Sample records for central heating system

  1. Prospects for development of heat supply systems in high-rise districts

    NASA Astrophysics Data System (ADS)

    Zhila, Viktor; Solovyeva, Elena

    2018-03-01

    The article analyzes the main advantages and disadvantages of centralized and decentralized heat supply systems in high-rise districts. The main schemes of centralized heat supply systems are considered. They include centralized heat supply from boiler houses, centralized heat supply from autonomous heat sources, heat supply from roof boiler houses and door-to-door heating supply. For each of these variant, the gas distribution systems are considered and analyzed. These systems vary depending on the heat source location. For each of these systems, technical and economic indicators are taken into account, the analysis of which allows choosing the best option for districts where high-rise buildings predominate.

  2. 77 FR 8178 - Test Procedures for Central Air Conditioners and Heat Pumps: Public Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-14

    ... distribution of those central air conditioning systems and heat pump systems manufactured after January 1, 2010... system central air conditioners and heat pumps be tested using ``the evaporator coil that is likely to... issued two guidance documents surrounding testing central air conditioner and heat pump systems utilizing...

  3. Research status and evaluation system of heat source evaluation method for central heating

    NASA Astrophysics Data System (ADS)

    Sun, Yutong; Qi, Junfeng; Cao, Yi

    2018-02-01

    The central heating boiler room is a regional heat source heating center. It is also a kind of the urban environment pollution, it is an important section of building energy efficiency. This article through to the evaluation method of central heating boiler room and overviews of the researches during domestic and overseas, summarized the main influence factors affecting energy consumption of industrial boiler under the condition of stable operation. According to the principle of establishing evaluation index system. We can find that is great significance in energy saving and environmental protection for the content of the evaluation index system of the centralized heating system.

  4. Final Report. Montpelier District Energy Project

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

    Baker, Jessie; Motyka, Kurt; Aja, Joe

    2015-03-30

    The City of Montpelier, in collaboration with the State of Vermont, developed a central heat plant fueled with locally harvested wood-chips and a thermal energy distribution system. The project provides renewable energy to heat a complex of state buildings and a mix of commercial, private and municipal buildings in downtown Montpelier. The State of Vermont operates the central heat plant and the system to heat the connected state buildings. The City of Montpelier accepts energy from the central heat plant and operates a thermal utility to heat buildings in downtown Montpelier which elected to take heat from the system.

  5. 7 CFR 1721.104 - Eligible purposes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... measures: (i) Caulking; (ii) Weather-stripping; (iii) Heat pump systems (including water source heat pumps); (iv) Heat pumps, water heaters, and central heating or central air conditioning system replacements or modifications, which reduce energy consumption; (v) Ceiling insulation; (vi) Wall insulation; (vii) Floor...

  6. 7 CFR 1721.104 - Eligible purposes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... measures: (i) Caulking; (ii) Weather-stripping; (iii) Heat pump systems (including water source heat pumps); (iv) Heat pumps, water heaters, and central heating or central air conditioning system replacements or modifications, which reduce energy consumption; (v) Ceiling insulation; (vi) Wall insulation; (vii) Floor...

  7. 7 CFR 1721.104 - Eligible purposes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... measures: (i) Caulking; (ii) Weather-stripping; (iii) Heat pump systems (including water source heat pumps); (iv) Heat pumps, water heaters, and central heating or central air conditioning system replacements or modifications, which reduce energy consumption; (v) Ceiling insulation; (vi) Wall insulation; (vii) Floor...

  8. 7 CFR 1721.104 - Eligible purposes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... measures: (i) Caulking; (ii) Weather-stripping; (iii) Heat pump systems (including water source heat pumps); (iv) Heat pumps, water heaters, and central heating or central air conditioning system replacements or modifications, which reduce energy consumption; (v) Ceiling insulation; (vi) Wall insulation; (vii) Floor...

  9. 7 CFR 1721.104 - Eligible purposes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... measures: (i) Caulking; (ii) Weather-stripping; (iii) Heat pump systems (including water source heat pumps); (iv) Heat pumps, water heaters, and central heating or central air conditioning system replacements or modifications, which reduce energy consumption; (v) Ceiling insulation; (vi) Wall insulation; (vii) Floor...

  10. System design package for the solar heating and cooling central data processing system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The central data processing system provides the resources required to assess the performance of solar heating and cooling systems installed at remote sites. These sites consist of residential, commercial, government, and educational types of buildings, and the solar heating and cooling systems can be hot-water, space heating, cooling, and combinations of these. The instrumentation data associated with these systems will vary according to the application and must be collected, processed, and presented in a form which supports continuity of performance evaluation across all applications. Overall software system requirements were established for use in the central integration facility which transforms raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems.

  11. A new test procedure to evaluate the performance of substations for collective heating systems

    NASA Astrophysics Data System (ADS)

    Baetens, Robin; Verhaert, Ivan

    2017-11-01

    The overall heat demand of a single dwelling, existing out of space heating and domestic hot water production, decreases due to higher insulation rates. Because of this, investing in efficient and renewable heat generation becomes less interesting. Therefore, to incorporate renewables or residual heat on a larger scale, district heating or collective heating systems grow in importance. Within this set-up, the substation is responsible for the interaction between local demand for comfort and overall energy performance of the collective heating system. Many different configurations of substations exist, which influence both local comfort and central system performance. Next to that, also hybrids exist with additional local energy input. To evaluate performance of such substations, a new experimental-based test procedure is developed in order to evaluate these different aspects, characterized by the two roles a substation has, namely as heat generator and as heat consumer. The advantage of this approach is that an objective comparison between individual and central systems regarding performance on delivering local comfort can be executed experimentally. The lab set-up consists out of three different subsystems, namely the central system, the domestic hot water consumption and the local space heating. The central system can work with different temperature regimes and control strategies, as these aspects have proven to have the largest influence on actual performance. The domestic hot water system is able to generate similar tap profiles according to eco-design regulation for domestic hot water generation. The space heating system is able to demand a modular heat load.

  12. German central solar heating plants with seasonal heat storage

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

    Bauer, D.; Marx, R.; Nussbicker-Lux, J.

    2010-04-15

    Central solar heating plants contribute to the reduction of CO{sub 2}-emissions and global warming. The combination of central solar heating plants with seasonal heat storage enables high solar fractions of 50% and more. Several pilot central solar heating plants with seasonal heat storage (CSHPSS) built in Germany since 1996 have proven the appropriate operation of these systems and confirmed the high solar fractions. Four different types of seasonal thermal energy stores have been developed, tested and monitored under realistic operation conditions: Hot-water thermal energy store (e.g. in Friedrichshafen), gravel-water thermal energy store (e.g. in Steinfurt-Borghorst), borehole thermal energy store (inmore » Neckarsulm) and aquifer thermal energy store (in Rostock). In this paper, measured heat balances of several German CSHPSS are presented. The different types of thermal energy stores and the affiliated central solar heating plants and district heating systems are described. Their operational characteristics are compared using measured data gained from an extensive monitoring program. Thus long-term operational experiences such as the influence of net return temperatures are shown. (author)« less

  13. Acute lower respiratory tract infections in infants: the influence of central heating systems

    PubMed Central

    Stott, N. C. H.; West, R. R.

    1981-01-01

    A cohort of 342 infants in a group practice population were studied during the first year of life to assess whether hot-air central heating was associated with more severe respiratory infections than radiator central heating. Infants born into council house families with ducted hot-air central heating were at no greater risk of contracting severe respiratory infections than those with radiator central heating. The risk of a respiratory infection was positively correlated with size of sibship and maternal smoking habits. PMID:7277291

  14. A central solar domestic hot water system - Performance and economic analysis

    NASA Astrophysics Data System (ADS)

    Wolf, D.; Tamir, A.; Kudish, A. I.

    1980-02-01

    A solar-assisted central hot water system was retrofitted onto one of the student dormitory complexes. The system consisted of twenty commercial solar collectors, of the pipe and plate type, and central hot water tank connected to two dormitory buildings. The system has two loops: (1) a solar loop, in which the heated water circulates between the collector panels and the central hot water tank, and (2) a consumer loop, where the solar-heated water circulates between the central hot water tank and the dormitory. The solar-heated water circulates through the individual electric hot water tanks which serve as individual hot water storage and booster units, and the mains water is introduced at the bottom of the central tank to replace consumed water. The description of the system, the design and its performance, together with an economic analysis, are presented.

  15. 24 CFR 201.10 - Loan amounts.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... dealer's cost of purchasing and installing a central air conditioning system or heat pump, if not... cost of purchasing and installing a central air conditioning system or heat pump, if not installed by...

  16. Investigating the interactions of decentralized and centralized wastewater heat recovery systems.

    PubMed

    Sitzenfrei, Robert; Hillebrand, Sebastian; Rauch, Wolfgang

    2017-03-01

    In the urban water cycle there are different sources for extracting energy. In addition to potential and chemical energy in the wastewater, thermal energy can also be recovered. Heat can be recovered from the wastewater with heat exchangers that are located decentralized and/or centralized at several locations throughout the system. It can be recovered directly at the source (e.g. in the showers and bathrooms), at building block level (e.g. warm water tanks collecting all grey water), in sewers or at the wastewater treatment plant. However, an uncoordinated installation of systems on such different levels can lead to competing technologies. To investigate these interactions, a modelling environment is set up, tested and calibrated based on continuous sewer temperature and flow measurements. With that approach different heat recovery scenarios on a household level (decentralized) and of in-sewer heat recovery (centralized) are investigated. A maximum performance drop of 40% for a centralized energy recovery system was estimated when all bathrooms are equipped with decentralized recovery systems. Therefore, the proposed modelling approach is suitable for testing different future conditions and to identify robust strategies for heat recovery systems from wastewater.

  17. Classifications of central solar domestic hot water systems

    NASA Astrophysics Data System (ADS)

    Guo, J. Y.; Hao, B.; Peng, C.; Wang, S. S.

    2016-08-01

    Currently, there are many means by which to classify solar domestic hot water systems, which are often categorized according to their scope of supply, solar collector positions, and type of heat storage tank. However, the lack of systematic and scientific classification as well as the general disregard of the thermal performance of the auxiliary heat source is important to DHW systems. Thus, the primary focus of this paper is to determine a classification system for solar domestic hot water systems based on the positions of the solar collector and auxiliary heating device, both respectively and in combination. Field-testing data regarding many central solar DHW systems demonstrates that the position of the auxiliary heat source clearly reflects the operational energy consumption. The consumption of collective auxiliary heating hot water system is much higher than individual auxiliary heating hot water system. In addition, costs are significantly reduced by the separation of the heat storage tank and the auxiliary heating device.

  18. Energy Corner: Heat Reclamation Rescues Wasted Heat.

    ERIC Educational Resources Information Center

    Daugherty, Thomas

    1982-01-01

    Heat reclamation systems added to pre-existing central heating systems provide maximum savings at minimum cost. The benefits of a particular appliance marketed under the brand name "Energizer" are discussed. (Author/MLF)

  19. Appendices of an appraisal for the use of geothermal energy in state-owned buildings in Colorado. Section D. Durango

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

    Meyer, R.T.; Coe, B.A.; Dick, J.D.

    1981-01-01

    Four state-owned building complexes ahve been evaluated within the city of Durango: The State Fish Hatchery, Fort Lewis College, new State Highway Department Building near the Bodo Industrial Park, and the National Guard Building. Three of the state facilities in Durango are evaluated for geothermal systems on thea ssumption of taking geothermal water from a trunk-line originating at the area northof Durango: State Fish Hatchery, Fort Lewis College and new State Highway Department Building. The National Guard Building is evaluated on the basis of a water-to-air heat pump, with warm water derived from a hypothetical shallow aquifer immediately below themore » building site. Two geothermal options were separately evaluated for Fort Lewis College: a central heat exchanger system for delivery of 145/sup 0/F heating water to the campus buildings and a central heat pump system for boosting the heating water to 200/sup 0/F prior to delivery to the buildings; both systems require the installation of a distribution piping network for the entire campus area. Retrofit engineering for the State Fish Hatchery provides for the installation of a small scale central distribution piping system to the several buildings, a central heat excanger coupled to the geothermal trunk line, and the use of various fan coil and unit heaters for space heating. An option is provided for discharge-mixing the geothermal water into the fish ponds and runs in order to raise the hatchery water temperature a couple degrees for increasing fish production and yield. The heating system for the new State Highway Department Building is redesigned to replace the natural-gas-fired forced-air furnaces with a heat exchanger, hot water fan coils and unit heaters.« less

  20. Inverse problem and variation method to optimize cascade heat exchange network in central heating system

    NASA Astrophysics Data System (ADS)

    Zhang, Yin; Wei, Zhiyuan; Zhang, Yinping; Wang, Xin

    2017-12-01

    Urban heating in northern China accounts for 40% of total building energy usage. In central heating systems, heat is often transferred from heat source to users by the heat network where several heat exchangers are installed at heat source, substations and terminals respectively. For given overall heating capacity and heat source temperature, increasing the terminal fluid temperature is an effective way to improve the thermal performance of such cascade heat exchange network for energy saving. In this paper, the mathematical optimization model of the cascade heat exchange network with three-stage heat exchangers in series is established. Aim at maximizing the cold fluid temperature for given hot fluid temperature and overall heating capacity, the optimal heat exchange area distribution and the medium fluids' flow rates are determined through inverse problem and variation method. The preliminary results show that the heat exchange areas should be distributed equally for each heat exchanger. It also indicates that in order to improve the thermal performance of the whole system, more heat exchange areas should be allocated to the heat exchanger where flow rate difference between two fluids is relatively small. This work is important for guiding the optimization design of practical cascade heating systems.

  1. Subsystem design package for Mod 2 site data acquisition system: Solar heating and cooling

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The Mod II Site Data Acquisition Subsystem (SDAS) is designed to collect data from sensors located on residential or commercial buildings using a solar heating and/or cooling system. The SDAS takes the data obtained from sensors located on the solar heating and/or cooling system, processes the data into a suitable format, stores the data for a period of time, and provides the capability for both telephone retrieval by the Central Data Processing System (CDPS) and manual retrieval of the data for transfer to the central site. The unit is designed so it will not degrade the operation of the solar heating/cooling system which it is monitoring.

  2. System design package for solar heating and cooling site data acquisition subsystem

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Site Data Acquisition Subsystem (SDAS) designed to collect data from sensors located on residential or commercial buildings using a solar heating and/or cooling system is described. It takes the data obtained from sensors located on the solar system, processes the data into suitable format, stores the data for a period of time, and provides the capability for either telephone retrieval by the central data processing system or manual retrieval of the data for transfer to a central site. The SDAS is also designed so that it will not degrade the operation of the solar heating/cooling system which it is monitoring.

  3. Application analysis of solar total energy systems to the residential sector. Volume III, conceptual design. Final report

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

    Not Available

    1979-07-01

    The objective of the work described in this volume was to conceptualize suitable designs for solar total energy systems for the following residential market segments: single-family detached homes, single-family attached units (townhouses), low-rise apartments, and high-rise apartments. Conceptual designs for the total energy systems are based on parabolic trough collectors in conjunction with a 100 kWe organic Rankine cycle heat engine or a flat-plate, water-cooled photovoltaic array. The ORC-based systems are designed to operate as either independent (stand alone) systems that burn fossil fuel for backup electricity or as systems that purchase electricity from a utility grid for electrical backup.more » The ORC designs are classified as (1) a high temperature system designed to operate at 600/sup 0/F and (2) a low temperature system designed to operate at 300/sup 0/F. The 600/sup 0/F ORC system that purchases grid electricity as backup utilizes the thermal tracking principle and the 300/sup 0/F ORC system tracks the combined thermal and electrical loads. Reject heat from the condenser supplies thermal energy for heating and cooling. All of the ORC systems utilize fossil fuel boilers to supply backup thermal energy to both the primary (electrical generating) cycle and the secondary (thermal) cycle. Space heating is supplied by a central hot water (hydronic) system and a central absorption chiller supplies the space cooling loads. A central hot water system supplies domestic hot water. The photovoltaic system uses a central electrical vapor compression air conditioning system for space cooling, with space heating and domestic hot water provided by reject heat from the water-cooled array. All of the systems incorporate low temperature thermal storage (based on water as the storage medium) and lead--acid battery storage for electricity; in addition, the 600/sup 0/F ORC system uses a therminol-rock high temperature storage for the primary cycle. (WHK)« less

  4. Storage systems for solar thermal power

    NASA Technical Reports Server (NTRS)

    Calogeras, J. E.; Gordon, L. H.

    1978-01-01

    The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.

  5. Evolution of the Cerro Prieto geothermal system as interpreted from vitrinite reflectance under isothermal conditions

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

    Barker, C.E.; Pawlewicz, M.J.; Bostick, N.H.

    1981-01-01

    Temperature estimates from reflectance data in the Cerro Prieto system correlate with modern temperature logs and temperature estimates from fluid inclusion and oxygen isotope geothermometry indicating that the temperature in the central portion of the Cerro Prieto System is now at its historical maximum. Isoreflectance lines formed by contouring vitrinite reflectance data for a given isothermal surface define an imaginary surface that indicates an apparent duration of heating in the system. The 250/sup 0/C isothermal surface has a complex dome-like form suggesting a localized heat source that has caused shallow heating in the central portion of this system. Isoreflectance linesmore » relative to this 250/sup 0/C isothermal surface define a zone of low reflectance roughly corresponding to the crest of the isothermal surface. Comparison of these two surfaces suggest that the shallow heating in the central portion of Cerro Prieto is young relative to the heating (to 250/sup 0/C) on the system margins. Laboratory and theoretical models of hydrothermal convection cells suggest that the form of the observed 250/sup 0/C isothermal surface and the reflectance surface derived relative to it results from the convective rise of thermal fluids under the influence of a regional hydrodynamic gradient that induces a shift of the hydrothermal heating effects to the southwest.« less

  6. Preliminary design review package for the solar heating and cooling central data processing system

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The Central Data Processing System (CDPS) is designed to transform the raw data collected at remote sites into performance evaluation information for assessing the performance of solar heating and cooling systems. Software requirements for the CDPS are described. The programming standards to be used in development, documentation, and maintenance of the software are discussed along with the CDPS operations approach in support of daily data collection and processing.

  7. Availability of Heat to Drive Hydrothermal Systems in Large Martian Impact Craters

    NASA Technical Reports Server (NTRS)

    Thorsos, I. E.; Newsom, H. E.; Davies, A. G.

    2001-01-01

    The central uplift in large craters on Mars can provide a substantial source of heat, equivalent to heat produced by the impact melt sheet. The heat generated in large impacts could play a significant role in hydrothermal systems on Mars. Additional information is contained in the original extended abstract.

  8. Automatic temperature adjustment apparatus

    DOEpatents

    Chaplin, James E.

    1985-01-01

    An apparatus for increasing the efficiency of a conventional central space heating system is disclosed. The temperature of a fluid heating medium is adjusted based on a measurement of the external temperature, and a system parameter. The system parameter is periodically modified based on a closed loop process that monitors the operation of the heating system. This closed loop process provides a heating medium temperature value that is very near the optimum for energy efficiency.

  9. Malgorzata Kasperska Henryk Bunka

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

    NONE

    The MarCo Engineering Company Ltd. has its registered seat at Gdynia and was established in 1990. We are the exclusive representative for Poland of the world`s renowned manufacturers of heat distribution network products; Through six subsidiaries (Gdynia, Warsaw, Wroclaw, Cracow, Gliwice and Lublin) and our dealers` network all over Poland the following products and services are offered: (1) automatic control systems for heating and air conditioning; (2) a supervisory remote control system for heat distribution centers; (3) compensating devices for central heating and household hot water installations; (4) radiator thermostatic valves; (5) Meinecke water meters; (6) thermal energy counters; (6)more » a remote calorimeter data reading system SIOX; (7) an electronic central heating costs sharing system - GT-15; (8) compact thermal stations; and (9) compact and pipe exchangers. The modern, high standard devices offered have achieved much success on the Polish market.« less

  10. Heat Pumps and Combined Heat and Power | Climate Neutral Research Campuses

    Science.gov Websites

    heat and power (CHP) systems on research campuses can reduce climate impact by 15% to 30% and yield a take advantage of large central heating plants and steam distribution systems that are available on climate impact. The material handling and combustion systems used for coal are often suitable for partial

  11. Integration of Decentralized Thermal Storages Within District Heating (DH) Networks

    NASA Astrophysics Data System (ADS)

    Schuchardt, Georg K.

    2016-12-01

    Thermal Storages and Thermal Accumulators are an important component within District Heating (DH) systems, adding flexibility and offering additional business opportunities for these systems. Furthermore, these components have a major impact on the energy and exergy efficiency as well as the heat losses of the heat distribution system. Especially the integration of Thermal Storages within ill-conditioned parts of the overall DH system enhances the efficiency of the heat distribution. Regarding an illustrative and simplified example for a DH system, the interactions of different heat storage concepts (centralized and decentralized) and the heat losses, energy and exergy efficiencies will be examined by considering the thermal state of the heat distribution network.

  12. The analysis of thermal network of district heating system from investor point of view

    NASA Astrophysics Data System (ADS)

    Takács, Ján; Rácz, Lukáš

    2016-06-01

    The hydraulics of a thermal network of a district heating system is a very important issue, to which not enough attention is often paid. In this paper the authors want to point out some of the important aspects of the design and operation of thermal networks in district heating systems. The design boundary conditions of a heat distribution network and the requirements on active pressure - circulation pump - influencing the operation costs of the centralized district heating system as a whole, are analyzed in detail. The heat generators and the heat exchange stations are designed according to the design heat loads after thermal insulation, and modern boiler units are installed in the heating plant.

  13. Space shuttle heat pipe thermal control systems

    NASA Technical Reports Server (NTRS)

    Alario, J.

    1973-01-01

    Heat pipe (HP) thermal control systems designed for possible space shuttle applications were built and tested under this program. They are: (1) a HP augmented cold rail, (2) a HP/phase change material (PCM) modular heat sink and (3) a HP radiating panel for compartment temperature control. The HP augmented cold rail is similar to a standard two-passage fluid cold rail except that it contains an integral, centrally located HP throughout its length. The central HP core helps to increase the local power density capability by spreading concentrated heat inputs over the entire rail. The HP/PCM modular heat sink system consists of a diode HP connected in series to a standard HP that has a PCM canister attached to its mid-section. It is designed to connect a heat source to a structural heat sink during normal operation, and to automatically decouple from it and sink to the PCM whenever structural temperatures are too high. The HP radiating panel is designed to conductively couple the panel feeder HPs directly to a fluid line that serves as a source of waste heat. It is a simple strap-on type of system that requires no internal or external line modifications to distribute the heat to a large radiating area.

  14. Side-by-Side Testing of Water Heating Systems: Results from the 2013-2014 Evaluation

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

    Colon, Carlos

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  15. Thermal energy supply optimization for Edgewood Area, US Army Aberdeen Proving Ground: Energy supply alternatives. Final report

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

    McCammon, T.L.; Dilks, C.L.; Savoie, M.J.

    1995-09-01

    Relatively poor performance at the aging central heating plants (OH Ps) and planned changes in steam demand at Aberdeen Proving Ground (APG) Edgewood Area, Aberdeen, MD warranted an investigation of alternatives for providing thermal energy to the installation. This study: (1) evaluated the condition of the APG CHPs and heat distribution system, (2) identified thermal energy supply problems and cost-effective technologies to maintain APG`s capability to produce and distribute the needed thermal energy, and (3) recommended renovation and modernization projects for the system. Heating loads were analyzed using computer simulations, and life cycle costs were developed for each alternative. Recommendedmore » alternatives included upgrading the existing system, installing new boilers, consolidating the central heating plants, and introducing the use of absorption chilling.« less

  16. Steamtown District Heating and Cooling Project, Scranton, Pennsylvania. Final report

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

    NONE

    This report summarizes the activities of a study intended to examine the feasibility of a district heating and cooling alternative for the Steamtown National Historic Site in Scranton, PA. The objective of the study was to investigate the import of steam from the existing district heating system in Scranton which is operated by the Community Central Energy Corporation and through the use of modern technology provide hot and chilled water to Steamtown for its internal heating and cooling requirements. Such a project would benefit Steamtown by introducing a clean technology, eliminating on-site fuel use, avoiding first costs for central heatingmore » and cooling plants and reducing operation and maintenance expenditures. For operators of the existing district heating system, this project represents an opportunity to expand their customer base and demonstrate new technologies. The study was conducted by Joseph Technology Corporation, Inc. and performed for the Community Central Energy Corporation through a grant by the US Department of Energy. Steamtown was represented by the National Park Service, the developers of the site.« less

  17. Phased Retrofits in Existing Homes in Florida Phase II: Shallow Plus Retrofits

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

    Sutherland, K.; Parker, D.; Martin, E.

    Originally published in February 2016, this revision contains an added section called 'Evaluation of Complete Central System Replacement with Inverter-Driven Heat Pump,' which presents the designs and energy savings evaluations of two different schemes wherein inverter-driven systems replaced a home's existing central system. Analyses for three additional retrofit measures were bolstered by longer-term data; these are described in the sections on supplemental mini-split heat pumps (MSHPs), smart thermostats, and heat pump clothes dryers. The sections on supplemental MSHPs and smart thermostats were also enhanced with larger sample sizes and projections of weather-normalized annual energy savings. Finally, peak system hour energymore » demand-reduction predictions are provided for all retrofit measures where meaningful impacts could be drawn.« less

  18. Phased Retrofits in Existing Homes in Florida Phase II: Shallow Plus Retrofits

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

    Sutherland, K.; Parker, D.; Martin, E.

    Originally published in February 2016, this revision contains an added section called 'Evaluation of Complete Central System Replacement with Inverter-Driven Heat Pump,' which presents the designs and energy savings evaluations of two different schemes wherein inverter-driven systems replaced a home’s existing central system. Analyses for three additional retrofit measures were bolstered by longer-term data; these are described in the sections on supplemental mini-split heat pumps (MSHPs), smart thermostats, and heat pump clothes dryers. The sections on supplemental MSHPs and smart thermostats were also enhanced with larger sample sizes and projections of weather-normalized annual energy savings. Finally, peak system hour energymore » demand-reduction predictions are provided for all retrofit measures where meaningful impacts could be drawn.« less

  19. A feasibility study on solar utility total energy system /SUTES/

    NASA Astrophysics Data System (ADS)

    Bilgen, E.

    1980-11-01

    A fully dedicated central receiver solar utility (CRSU) designed to meet domestic energy requirements for space heating and hot water has been synthesized and assessed at the conceptual level. The solar utility total energy system (SUTES) integrates (1) a central receiver solar utility (CRSU), (2) an electrical power generating system (EPGS), (3) a hydrogen production plant (HPP), (4) a water chilling system for cooling, heat pump system (HPS), (5) necessary thermal energy storage systems (TES), (6) a district heating and cooling system (DH&CS). All subsystems are close-coupled. Using consistent costing bases, it has been found that the SUTES concept provides energy costs which are lower than those provided by a CRSU. Representative costs are $3.14/GJ versus $8.56/GJ for 10 percent recovery factor and $12.55/GJ versus $13.47/GJ for 17.5 percent recovery factor.

  20. Practical results of heat conservation in a housing estate scale-actions implemented by the Pradnik-Bialy-Zachod housing cooperative in Cracow

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

    Piotrowski, L.

    1995-12-31

    There are 11,600,000 apartments occupied in Poland. More than 7,700,000 of these apartments are located in towns. Energy consumption for heating, ventilation and district hot water in residential housing reaches 40% of the national power balance. A portion of district heat distribution and relatively low energy efficiency is characteristic for Polish residential housing. Seventy five percent of apartments in towns are provided with central heating installations and 55% of the entire heat demand in Polish buildings is covered by district heating systems. The total installed heat power of these systems reaches 46,000 MW. The situation with regard to conservation inmore » Polish residential housing is directly related to the legacy of central planning of the national economy and to the current phase of its re-organization to the market-oriented system. The standard value of the overall heat-transfer coefficient for external walls in Poland until 1980 was 1.16 W/m{sup 2}K; at present it is reduced to 0.55 W/m{sup 2}K. There are numerous reasons for the low energy efficiency in residential housing. These reasons are discussed.« less

  1. Central Data Processing System (CDPS) user's manual: Solar heating and cooling program

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The software and data base management system required to assess the performance of solar heating and cooling systems installed at multiple sites is presented. The instrumentation data associated with these systems is collected, processed, and presented in a form which supported continuity of performance evaluation across all applications. The CDPS consisted of three major elements: communication interface computer, central data processing computer, and performance evaluation data base. Users of the performance data base were identified, and procedures for operation, and guidelines for software maintenance were outlined. The manual also defined the output capabilities of the CDPS in support of external users of the system.

  2. Steam dispatching control system demonstration at Fort Benjamin Harrison. Final technical report

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

    Diks, C.L.; Moshage, R.E.; Lin, M.C.

    1993-07-01

    Currently most Army Central steam heating systems operate by maintaining a constant steam pressure regardless of actual steam demand. This method offers some operational convenience, but is often the cause of significant energy losses. Researchers at the U.S. Army Construction Engineering Research Laboratories (USACERL) have investigated the Steam Dispatching Control System (SDCS), a control system that lowers supply steam pressure-and therefore steam temperature-to slightly above the amount needed to meet the steam demand. The lower Steam temperature and reduction in steam loss (from leaks and faulty traps) result in lower heat losses and higher energy savings. Limiting steam pressure canmore » diminish the amount of excess heat loss in the distribution system while still meeting the demand. The Army's Facilities Engineering Applications Program (FEAP) chose Fort Benjamin Harrison, IN, as the Army demonstration site for SDCS. Researchers found that use of SDCS is technically and economically viable improvement over current operating procedures. Analysis based on demonstration results show that the simple payback for SDCS is less than 1 year. The results of this demonstration are generally applicable to installations with a large central heating plant and a substantial steam distribution system. Findings, indicate that energy savings form SDCS are significant regardless of what type of fuel powers the boiler. The authors note that, during the initial evaluation of a potential SDCS application, attention must be paid to the condensate return to ensure that it will operate properly. Fort Benjamin Harrison, IN, Steam Dispatching Control System(SDCS), Central heating plants, energy conservation.« less

  3. Mathematical model for calculation of the heat-hydraulic modes of heating points of heat-supplying systems

    NASA Astrophysics Data System (ADS)

    Shalaginova, Z. I.

    2016-03-01

    The mathematical model and calculation method of the thermal-hydraulic modes of heat points, based on the theory of hydraulic circuits, being developed at the Melentiev Energy Systems Institute are presented. The redundant circuit of the heat point was developed, in which all possible connecting circuits (CC) of the heat engineering equipment and the places of possible installation of control valve were inserted. It allows simulating the operating modes both at central heat points (CHP) and individual heat points (IHP). The configuration of the desired circuit is carried out automatically by removing the unnecessary links. The following circuits connecting the heating systems (HS) are considered: the dependent circuit (direct and through mixing elevator) and independent one (through the heater). The following connecting circuits of the load of hot water supply (HWS) were considered: open CC (direct water pumping from pipelines of heat networks) and a closed CC with connecting the HWS heaters on single-level (serial and parallel) and two-level (sequential and combined) circuits. The following connecting circuits of the ventilation systems (VS) were also considered: dependent circuit and independent one through a common heat exchanger with HS load. In the heat points, water temperature regulators for the hot water supply and ventilation and flow regulators for the heating system, as well as to the inlet as a whole, are possible. According to the accepted decomposition, the model of the heat point is an integral part of the overall heat-hydraulic model of the heat-supplying system having intermediate control stages (CHP and IHP), which allows to consider the operating modes of the heat networks of different levels connected with each other through CHP as well as connected through IHP of consumers with various connecting circuits of local systems of heat consumption: heating, ventilation and hot water supply. The model is implemented in the Angara data-processing complex. An example of the multilevel calculation of the heat-hydraulic modes of main heat networks and those connected to them through central heat point distribution networks in Petropavlovsk-Kamchatskii is examined.

  4. Limited energy study, Buildings 750 and 798, Fort Richardson, Alaska. Final report

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

    NONE

    1996-02-01

    The purpose of this study is to identify and evaluate Energy Conservation Opportunities (ECOs) for two motor pool facilities, Buildings 750 and 798, to determine their energy savings potential, economic feasibility, and to document results for possible future funding. Buildings 750 and 798 are heated by steam supplied from a central plant. The central plant uses natural gas as a primary fuel source to produce steam for both heating and electrical energy generation. Since power is produced on the base there is not a demand charge for electrical energy. Two ECOs examined the use of natural gas in conjunction withmore » steam as a method of heating the buildings. Annual baseline energy consumption and cost data for each building is presented. The heating system in Building 750 was found to be severely under capacity. This is the result of the disabling of the under-floor heating system and the roof top MAUs. Building 798 also has had the under-floor heating system disabled. However, baseline simulations show that the remaining system is capable of maintaining thermostat setpoints during all but the coldest days of a typical year.« less

  5. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from 2013-2014 Evaluation Final Report, Cocoa, FL

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

    Rothgeb, Stacey K; Colon, C.; Martin, E.

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  6. Building America Case Study: Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation Final Report

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

    C. Colon and E. Martin

    The Florida Solar Energy Center (FSEC) has completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). This report contains a summary of research activities regarding the evaluation of two residential electric heat pump water heaters (HPWHs), a solar thermal system utilizing a polymer glazed absorber and a high efficiency natural gas system.

  7. Thermal protection performance of magnetohydrodynamic heat shield system based on multipolar magnetic field

    NASA Astrophysics Data System (ADS)

    Kai, Li; Jun, Liu; Weiqiang, Liu

    2017-07-01

    In order to cover the shortage of dipole magnetic field in the magnetohydrodynamic(MHD) heat shield system, physical model of a multipolar magnetic field with central and peripheral solenoids is constructed. By employing the governing equations of three dimensional thermochemical nonequilibrium flow with electromagnetic source terms based on the low magneto-Reynolds assumption, the flow control performance of the dipole and multipolar magnetic fields are numerically simulated. To make the results comparable, two groups of cases are designed by first assuming equal stagnation magnetic induction strength and secondly assuming equal ampere-turns. Results show that, the five-magnet system, whose central polar orientation is the same with the peripheral ones, have stronger work capability and better shock control and thermal protection performance. Moreover, the five-solenoid systems are the best when the ampere-turns of the central solenoid are twice and fourth of the peripheral ones under those two circumstances respectively. Compared with the dipole magnetic field, the stagnation non-catalytic heat fluxes are decreased by a factor of 47.5% and 34.0% respectively.

  8. Analysis of trends in the development of cities' heat supply systems

    NASA Astrophysics Data System (ADS)

    Stennikov, V. A.; Mednikova, E. E.

    2016-09-01

    New challenges—including the modern urban development policy, formation of the market of energy efficient technologies and different types of equipment of a broad power capacity range, tightening requirements to reliability, quality, and economic accessibility of heat supply—enhance the competitiveness of decentralized heat supply. In addition, its spontaneous growth and not always reasonable implementation lead to unjustified expenses, low efficiency, and ecological inconsistency. This proves the relevance of solving the problems of dividing an urban territory into zones of centralized heating (CH) and decentralized heating (DCH) along with their planning and justification, as well as determining a reasonable level of heat supply centralization and concentration of heat sources' power capacity. Solving these problems using the suggested method will allow optimizing the application areas for various types of heat supply and heat sources, justifying the degree of heat power capacity concentration and the extent of the systems as early as at the phase of a detailed urban planning project and then refining them during the design of urban heat supply systems. This will dramatically improve the reasonability of the decisions made and will simplify the procedure of their implementation. For criteria of limiting the extent (radius) of heat supply systems and defining their type, we suggest using standard values—the density of heat load per unit length of the pipeline and per unit area of urban territory. Standard values must be differentiated across the territory of Russia taking into account regional climatic and economic conditions and unique characteristics of heat supply development in cities and towns. The present article continues and develops the statements made in the previous articles created within the framework of the Theory of Hydraulic Circuits and takes into account the current situation and emerging trends in heat supply.

  9. Involvement of central, but not placental corticotropin releasing hormone (CRH) in heat stress induced immunosuppression during pregnancy.

    PubMed

    Nakamura, H; Nagase, H; Ogino, K; Hatta, K; Matsuzaki, I

    2001-03-01

    To clarify whether corticotropin releasing hormone (CRH) and beta-endorphin (betaEP) system mediate maternal immunosuppression in pregnant rats exposed to heat through central or placental pathway, we examined the effects of intravenous (iv) (100 or 500 microg) or intracerebroventricular (icv) (5 microg) administration of CRH receptor antagonist alpha-helical CRH (9-41) on splenic natural killer cell activity (NKCA) as well as betaEP in blood, pituitary lobes, and placenta in pregnant rats at 15 to 16 days gestation. Two-way ANOVA revealed that heat reduced NKCA and elevated blood and pituitary betaEP but did not change placental betaEP. Iv administered 500 microg and icv administered alpha-helical CRH reversed the reduced NKCA and the elevated pituitary betaEP, while iv administration of 100 microg alpha-helical CRH did not. The increased blood betaEP was reversed by iv 100 and 500 microg alpha-helical CRH and icv administration. Both iv and icv administrations reduced placental betaEP independent of heat exposure. Thus, the response of placental betaEP to iv administration of alpha-helical CRH seemed to be stronger than that of pituitary betaEP. These results indicate that alpha-helical CRH which acts on pituitary betaEP antagonizes heat-induced immunosuppression during pregnancy, suggesting that immunosuppression produced by heat stress during pregnancy is mediated by the central CRH system. The placental CRH-betaEP system seems unlikely to be involved in the immunosuppression. Physiologic roles of placental CRH and opioid system should be clarified by future in vitro experiments using placenta specimen including placental immunocyte.

  10. Solar space and water heating system at Stanford University, Central Food Services Building

    NASA Astrophysics Data System (ADS)

    1980-05-01

    This active hydronic domestic hot water and space heating system was 840 sq ft of single-glazed, liquid, flat plate collectors and 1550 gal heat storage tanks. The following are discussed: energy conservation, design philosophy, operation, acceptance testing, performance data, collector selection, bidding, costs, economics, problems, and recommendations. An operation and maintenance manual and as-built drawings are included in appendices.

  11. 16 CFR Appendix H to Part 305 - Cooling Performance and Cost for Central Air Conditioners

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... for Central Air Conditioners Manufacturer's rated cooling capacities (Btu's/hr.) Range of SEER's Low High Single Package Units Central Air Conditioners (Cooling Only): All capacities 10.6 16.5 Heat Pumps (Cooling Function): All capacities 10.6 16.0 Split System Units Central Air Conditioners (Cooling Only...

  12. Human Cardiovascular Responses to Passive Heat Stress

    PubMed Central

    Crandall, Craig G.; Wilson, Thad E.

    2016-01-01

    Heat stress increases human morbidity and mortality compared to normothermic conditions. Many occupations, disease states, as well as stages of life are especially vulnerable to the stress imposed on the cardiovascular system during exposure to hot ambient conditions. This review focuses on the cardiovascular responses to heat stress that are necessary for heat dissipation. To accomplish this regulatory feat requires complex autonomic nervous system control of the heart and various vascular beds. For example, during heat stress cardiac output increases up to twofold, by increases in heart rate and an active maintenance of stroke volume via increases in inotropy in the presence of decreases in cardiac preload. Baroreflexes retain the ability to regulate blood pressure in many, but not all, heat stress conditions. Central hypovolemia is another cardiovascular challenge brought about by heat stress, which if added to a subsequent central volumetric stress, such as hemorrhage, can be problematic and potentially dangerous, as syncope and cardiovascular collapse may ensue. These combined stresses can compromise blood flow and oxygenation to important tissues such as the brain. It is notable that this compromised condition can occur at cardiac outputs that are adequate during normothermic conditions but are inadequate in heat because of the increased systemic vascular conductance associated with cutaneous vasodilation. Understanding the mechanisms within this complex regulatory system will allow for the development of treatment recommendations and countermeasures to reduce risks during the ever-increasing frequency of severe heat events that are predicted to occur. PMID:25589263

  13. Developing a strategy for improving efficiency in the heating sector in central and eastern Europe

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

    Meyer, A.S.

    1995-12-31

    Heating is a vital energy service in Central and Eastern Europe, but the current delivery mechanisms are riddled with problems. District heating (DH) in its present technical form and with the present management structures is an inefficient system which produces expensive heat. Customers cannot control it and react to overheating by opening windows, even in winter. DH facilities together with other forms of individual heating are responsible for air pollution, causing severe impacts on the health of urban residents. The issues relating to DH are discussed, the first World Bank activities and experiences with projects in Poland are analyzed, andmore » the cornerstones of a strategy to support future World Bank financing and the development of sound heating policies in CEE are presented.« less

  14. 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.

  15. Optimization and thermoeconomics research of a large reclaimed water source heat pump system.

    PubMed

    Zhang, Zi-ping; Du, Fang-hui

    2013-01-01

    This work describes a large reclaimed water source heat pump system (RWSHPS) and elaborates on the composition of the system and its design principles. According to the characteristics of the reclaimed water and taking into account the initial investment, the project is divided into two stages: the first stage adopts distributed heat pump heating system and the second adopts the combination of centralized and decentralized systems. We analyze the heating capacity of the RWSHPS, when the phase II project is completed, the system can provide hydronic heating water with the supply and return water temperature of 55°C/15°C and meet the hydronic heating demand of 8 million square meters of residential buildings. We make a thermal economics analysis by using Thermal Economics theory on RWSHPS and gas boiler system, it is known that the RWSHPS has more advantages, compared with the gas boiler heating system; both its thermal efficiency and economic efficiency are relatively high. It provides a reference for future applications of the RWSHPS.

  16. Hydronic Heating Retrofits for Low-Rise Multifamily Buildings: Boiler Control Replacement and Monitoring

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

    Dentz, J.; Henderson, H.; Varshney, K.

    2013-10-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. of Cambridge, Massachusetts, to implement and study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating control systems in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded.

  17. HSP70 protects rats and hippocampal neurons from central nervous system oxygen toxicity by suppression of NO production and NF-κB activation.

    PubMed

    Yi, Hongjie; Huang, Guoyang; Zhang, Kun; Liu, Shulin; Xu, Weigang

    2018-05-01

    During diving, central nervous system oxygen toxicity may cause drowning or barotrauma, which has dramatically limited the working benefits of hyperbaric oxygen in underwater operations and clinical applications. The aim of this study is to understand the effects and the underlying mechanism of heat shock protein 70 on central nervous system oxygen toxicity and its mechanisms in vivo and in vitro. Rats were given geranylgeranylacetone (800 mg/kg) orally to induce hippocampal expression of heat shock protein 70 and then treated with hyperbaric oxygen. The time course of hippocampal heat shock protein 70 expression after geranylgeranylacetone administration was measured. Seizure latency and first electrical discharge were recorded to evaluate the effects of HSP70 on central nervous system oxygen toxicity. Effects of inhibitors of nitric oxide synthase and nuclear factor-κB on the seizure latencies and changes in nitric oxide, nitric oxide synthase, and nuclear factor-κB levels in the hippocampus tissues were examined. In cell experiments, hippocampal neurons were transfected with a virus vector carrying the heat shock protein 70 gene (H3445) before hyperbaric oxygen treatment. Cell viability, heat shock protein 70 expression, nitric oxide, nitric oxide synthase, and NF-κB levels in neurons were measured. The results showed that heat shock protein 70 expression significantly increased and peaked at 48 h after geranylgeranylacetone was given. Geranylgeranylacetone prolonged the first electrical discharge and seizure latencies, which was reversed by neuronal nitric oxide synthase, inducible nitric oxide synthase and NF-κB inhibitors. Nitric oxide, nitric oxide synthase, and inducible nitric oxide synthase levels in the hippocampus were significantly increased after hyperbaric oxygen exposure, but reversed by geranylgeranylacetone, while heat shock protein 70 inhibitor quercetin could inhibit this effect of geranylgeranylacetone. In the in vitro study, heat shock protein 70-overexpression decreased the nitric oxide, nitric oxide synthase, and inducible nitric oxide synthase levels as well as the cytoplasm/nucleus ratio of nuclear factor-κB and protected neurons from hyperbaric oxygen-induced cell injury. In conclusion, overexpression of heat shock protein 70 in hippocampal neurons may protect rats from central nervous system oxygen toxicity by suppression of neuronal nitric oxide synthase and inducible nitric oxide synthase-mediated nitric oxide production and translocation of nuclear factor-κB to nucleus. Impact statement Because the pathogenesis of central nervous system oxygen toxicity (CNS-OT) remains unclear, there are few interventions available. To develop an efficient strategy against CNS-OT, it is necessary to understand its pathogenesis and in particular, the relevant key factors involved. This study examined the protective effects of heat shock protein 70 (HSP70) on CNS-OT via in vivo and in vitro experiments. Our results indicated that overexpression of HSP70 in hippocampal neurons may protect rats from CNS-OT by suppression of nNOS and iNOS-mediated NO production and the activation of NF-κB. These findings contribute to clarification of the role of HSP70 in CNS-OT and provide us a potential novel target to prevent CNS-OT. Clarification of the involvement of NO, NOS and NF-κB provides new insights into the mechanism of CNS-OT and may help us to develop new approach against it by interfering these molecules.

  18. Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

    DOEpatents

    Leung, Ka-Ngo; Gordon, K.C.; Kippenhan, D.O.; Purgalis, P.; Moussa, D.; Williams, M.D.; Wilde, S.B.; West, M.W.

    1987-10-16

    A large area directly heated lanthanum hexaboride (LaB/sub 6/) cathode system is disclosed. The system comprises a LaB/sub 6/ cathode element generally circular in shape about a central axis. The cathode element has a head with an upper substantially planar emission surface, and a lower downwardly and an intermediate body portion which diminishes in cross-section from the head towards the base of the cathode element. A central rod is connected to the base of the cathode element and extends along the central axis. Plural upstanding spring fingers are urged against an outer peripheral contact surface of the head end to provide a mechanical and electrical connection to the cathode element. 7 figs

  19. Solar heating and hot water system installed at James Hurst Elementary School, Portsmouth, Virginia

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Solar heating and a hot water system installed in an elementary school in Portsmouth, Virginia are examined. The building is zoned into four heating/cooling areas. Each area is equipped with an air handling unit that is monitored and controlled by central control and monitoring system. The solar system for the building uses a collector area of 3,630 sq. ft. of flat plate liquid collectors, and a 6,000 gallon storage tank. System descriptions, maintenance reports, detailed component specifications, and design drawings to evaluate this solar system are reported.

  20. Did we see the 2011 summer heat wave coming?

    NASA Astrophysics Data System (ADS)

    Luo, Lifeng; Zhang, Yan

    2012-05-01

    A series of climate extreme events affected many parts of the US during 2011, including the severe drought in Texas, the spring tornado outbreak in the southern states, and the weeklong summer heat wave in the Central Plains. Successful prediction of these events can better inform and prepare the general public to cope with these extremes. In this study, we investigate the operational capability of the new NCEP Climate Forecast System (CFSv2) in predicting the 2011 summer heat wave. We found that starting from April 2011, the operational CFSv2 forecast consistently suggested an elevated probability of extremely hot days during the forthcoming summer over the Central Plains, and as the summer was approaching the forecast became more certain about the summer heat wave in its geographic location, intensity and timing. This study demonstrates the capability of the new seasonal forecast system and its potential usefulness in decision making process.

  1. Recent trends (2003-2013) of land surface heat fluxes on the southern side of the central Himalayas, Nepal

    NASA Astrophysics Data System (ADS)

    Amatya, Pukar Man; Ma, Yaoming; Han, Cunbo; Wang, Binbin; Devkota, Lochan Prasad

    2015-12-01

    Novice efforts have been made in order to study the regional distribution of land surface heat fluxes on the southern side of the central Himalayas utilizing high-resolution remotely sensed products, but these have been on instantaneous scale. In this study the Surface Energy Balance System model is used to obtain annual averaged maps of the land surface heat fluxes for 11 years (2003-2013) and study their annual trends on the central Himalayan region. The maps were derived at 5 km resolution using monthly input products ranging from satellite derived to Global Land Data Assimilation System meteorological data. It was found that the net radiation flux is increasing as a result of decreasing precipitation (drier environment). The sensible heat flux did not change much except for the northwestern High Himalaya and High Mountains. In northwestern High Himalaya sensible heat flux is decreasing because of decrease in wind speed, ground-air temperature difference, and increase in winter precipitation, whereas in High Mountains it is increasing due to increase in ground-air temperature difference and high rate of deforestation. The latent heat flux has an overall increasing trend with increase more pronounced in the lower regions compared to high elevated regions. It has been reported that precipitation is decreasing with altitude in this region. Therefore, the increasing trend in latent heat flux can be attributed to increase in net radiation flux under persistent forest cover and irrigation land used for agriculture.

  2. Central Heating Plant site characterization report, Marine Corps Combat Development Command, Quantico, Virginia

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

    Not Available

    1990-08-01

    This report presents the methodology and results of a characterization of the operation and maintenance (O M) environment at the US Marine Corps (USMC) Quantico, Virginia, Central Heating Plant (CHP). This characterization is part of a program intended to provide the O M staff with a computerized artificial intelligence (AI) decision support system that will assist the plant staff in more efficient operation of their plant. 3 refs., 12 figs.

  3. Heating characteristics of the TRIPAS hyperthermia system for deep seated malignancy.

    PubMed

    Surowiec, A; Bicher, H I

    1995-01-01

    A deep heating hyperthermia device TRIPAS (a triapplicator system) consisting of three independent, dielectrically loaded horn applicators operating in phase at 300 MHz was investigated. The heating characteristics produced by this hyperthermia system were analyzed by means of thermochromic liquid-crystal cards and a modified CDRH (Center for Devices and Regulatory Health) elliptical phantom. Both homogenous and inhomogeneous phantoms were used, simulating high and low permittivity tissues (muscle and lung). These equivalent tissues were made of polyacrylamide gel. The semiquantitative heating pattern analysis showed a central heating of 1/3 of maximum heating at a depth of 10 cm in both homogenous (muscle) and heterogenous (muscle/fat) phantoms. Also more uniform temperature/SAR distributions were generated in muscle equivalent material than those in lung.

  4. Residential Central Air Conditioning and Heat Pump Installation – Workshop Outcomes

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

    Goetzler, William; Zogg, Robert; Young, Jim

    DOE's Building Technologies Office works with researchers and industry partners to develop and deploy technologies that can substantially reduce energy consumption in residential and commercial buildings. This report aims to advance BTO’s energy savings, emissions reduction, and other program goals by identifying research and development (R&D), demonstration and deployment, and other non-regulatory initiatives for improving the design and installation of residential central air conditioners (CAC) and central heat pumps (CHP). Improving the adoption of CAC/CHP design and installation best practices has significant potential to reduce equipment costs, improve indoor air quality and comfort, improve system performance, and most importantly, reducemore » household energy consumption and costs for heating and cooling by addressing a variety of common installation issues.« less

  5. Optimization and Thermoeconomics Research of a Large Reclaimed Water Source Heat Pump System

    PubMed Central

    Zhang, Zi-ping; Du, Fang-hui

    2013-01-01

    This work describes a large reclaimed water source heat pump system (RWSHPS) and elaborates on the composition of the system and its design principles. According to the characteristics of the reclaimed water and taking into account the initial investment, the project is divided into two stages: the first stage adopts distributed heat pump heating system and the second adopts the combination of centralized and decentralized systems. We analyze the heating capacity of the RWSHPS, when the phase II project is completed, the system can provide hydronic heating water with the supply and return water temperature of 55°C/15°C and meet the hydronic heating demand of 8 million square meters of residential buildings. We make a thermal economics analysis by using Thermal Economics theory on RWSHPS and gas boiler system, it is known that the RWSHPS has more advantages, compared with the gas boiler heating system; both its thermal efficiency and economic efficiency are relatively high. It provides a reference for future applications of the RWSHPS. PMID:24089607

  6. Large area directly heated lanthanum hexaboride cathode structure having predetermined emission profile

    DOEpatents

    Leung, Ka-Ngo; Gordon, Keith C.; Kippenham, Dean O.; Purgalis, Peter; Moussa, David; Williams, Malcom D.; Wilde, Stephen B.; West, Mark W.

    1989-01-01

    A large area directly heated lanthanum hexaboride (LaB.sub.6) cathode system (10) is disclosed. The system comprises a LaB.sub.6 cathode element (11) generally circular in shape about a central axis. The cathode element (11) has a head (21) with an upper substantially planar emission surface (23), and a lower downwardly and an intermediate body portion (26) which diminishes in cross-section from the head (21) towards the base (22) of the cathode element (11). A central rod (14) is connected to the base (22) of the cathode element (11) and extends along the central axis. Plural upstanding spring fingers (37) are urged against an outer peripheral contact surface (24) of the head end (21) to provide a mechanical and electrical connection to the cathode element (11).

  7. Ductless Mini-Split Heat Pump Comfort Evaluation

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

    Roth, K.; Sehgal, N.; Akers, C.

    2013-03-01

    Field tests were conducted in two homes in Austin, TX, to evaluate the comfort performance of ductless minisplit heat pumps (DMSHPs), measuring temperature and relative humidity measurements in four rooms in each home before and after retrofitting a central HVAC system with DMSHPs.

  8. Ductless Mini-Split Heat Pump Comfort Evaluation

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

    Roth, K.; Sehgal, N.; Akers, C.

    2013-03-01

    Field tests were conducted in two homes in Austin, TX to evaluate the comfort performance of ductless mini-split heat pumps (DMSHPs), measuring temperature and relative humidity measurements in four rooms in each home before and after retrofitting a central HVAC system with DMSHPs.

  9. [Pathophysiology of heat illness].

    PubMed

    Aruga, Tohru; Miyake, Yasufumi

    2012-06-01

    Human core temperature is strictly controlled by mechanism of radiation, conduction, convection, and evaporation from skin surface. Serial hot and humid climate induces dehydration which interferes heat pump-out from the body. Heart dysfunction is the third factor to rise body temperature. Hyperthermia and hypo-perfusion caused by dehydration and heart failure deteriorate specific organ functions, i.e. central nervous system, liver and renal functions and coagulation system. Disseminated intravascular coagulopathy is one of the standard indicators of severity and mortality of heat stroke.

  10. Performance and economics of the ACES and alternative residential heating and air conditioning systems in 115 US cities

    NASA Astrophysics Data System (ADS)

    Abbatiello, L. A.; Nephew, E. A.; Ballou, M. L.

    1981-03-01

    The efficiency and life cycle costs of the brine chiller minimal annual cycle energy system (ACES) for residential space heating, air conditioning, and water heating requirements are compared with three conventional systems. The conventional systems evaluated are a high performance air-to-air heat pump with an electric resistance water heater, an electric furnace with a central air conditioner and an electric resistance water heater, and a high performance air-to-air heat pump with a superheater unit for hot water production. Monthly energy requirements for a reference single family house are calculated, and the initial cost and annual energy consumption of the systems, providing identical energy services, are computed and compared. The ACES consumes one third to one half ot the electrical energy required by the conventional systems and delivers the same annual loads at comparable costs.

  11. Study of Thermal Control Systems for orbiting power systems

    NASA Technical Reports Server (NTRS)

    Howell, H. R.

    1981-01-01

    Thermal control system designs were evaluated for the 25 kW power system. Factors considered include long operating life, high reliability, and meteoroid hazards to the space radiator. Based on a cost advantage, the bumpered pumped fluid radiator is recommended for the initial 25 kW power system and intermediate versions up to 50 kW. For advanced power systems with heat rejection rates above 50 kW the lower weight of the advanced heat pipe radiator offsets the higher cost and this design is recommended. The power system payloads heat rejection allocations studies show that a centralized heat rejection system is the most weight and cost effective approach. The thermal interface between the power system and the payloads was addressed and a concept for a contact heat exchanger that eliminates fluid transfer between the power system and the payloads was developed. Finally, a preliminary design of the thermal control system, with emphasis on the radiator and radiator deployment mechanism, is presented.

  12. 26 CFR 1.856-3 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., the wiring in a building, plumbing systems, central heating, or central air-conditioning machinery, pipes or ducts, elevators or escalators installed in the building, or other items which are structural... operation of a business, such as machinery, printing press, transportation equipment which is not a...

  13. 26 CFR 1.856-3 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., the wiring in a building, plumbing systems, central heating, or central air-conditioning machinery, pipes or ducts, elevators or escalators installed in the building, or other items which are structural... operation of a business, such as machinery, printing press, transportation equipment which is not a...

  14. 26 CFR 1.856-3 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., the wiring in a building, plumbing systems, central heating, or central air-conditioning machinery, pipes or ducts, elevators or escalators installed in the building, or other items which are structural... operation of a business, such as machinery, printing press, transportation equipment which is not a...

  15. 26 CFR 1.856-3 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., the wiring in a building, plumbing systems, central heating, or central air-conditioning machinery, pipes or ducts, elevators or escalators installed in the building, or other items which are structural... operation of a business, such as machinery, printing press, transportation equipment which is not a...

  16. Building America Case Study: Multifamily Central Heat Pump Water Heaters, Davis, California

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

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16-month period were then used to validate a TRNSYS simulation model. The TRNSYSmore » model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.« less

  17. Minimum separation distances for natural gas pipeline and boilers in the 300 area, Hanford Site

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

    Daling, P.M.; Graham, T.M.

    1997-08-01

    The U.S. Department of Energy (DOE) is proposing actions to reduce energy expenditures and improve energy system reliability at the 300 Area of the Hanford Site. These actions include replacing the centralized heating system with heating units for individual buildings or groups of buildings, constructing a new natural gas distribution system to provide a fuel source for many of these units, and constructing a central control building to operate and maintain the system. The individual heating units will include steam boilers that are to be housed in individual annex buildings located at some distance away from nearby 300 Area nuclearmore » facilities. This analysis develops the basis for siting the package boilers and natural gas distribution systems to be used to supply steam to 300 Area nuclear facilities. The effects of four potential fire and explosion scenarios involving the boiler and natural gas pipeline were quantified to determine minimum separation distances that would reduce the risks to nearby nuclear facilities. The resulting minimum separation distances are shown in Table ES.1.« less

  18. Implications for organic maturation studies of evidence of a geologically rapid increase and stabilization of vitrinite reflectance at peak temperature: Cerro Prieto geothermal system, Mexico

    USGS Publications Warehouse

    Barker, C.E.

    1991-01-01

    A short-term rapid heating and cooling of the rock in well M-94 below 1300 m was caused by a pulse of hot water passing through the edge of the Cerro Prieto, Mexico, geothermal system. Below 1300 m, the peak paleotemperatures were about 225-250??C, but equilibrium well log temperatures indicate a decrease to 150-210??C at present. This hot water pulse sharply increased vitrinite reflectance to levels comparable to those measured in the central part of the system, even though studies of apatite fission-track annealing indicate that the duration of heating was only 100-101 yr in M-94, in contrast to 103-104 yr in the central part of the system. The quick change of the vitrinite reflectance geothermometer indicates that thermal maturation reactions can stabilize, after a geologically short period of heating, to a level consistent with peak temperature under moderate to high-temperature diagenesis in open, fluid-rich, geothermal systems. -from Author

  19. Fresh air indoors

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

    Kull, K.

    1988-09-01

    This article describes and compares ventilation systems for the control of indoor air pollution in residential housing. These include: local exhaust fans, whole-house fans, central exhaust with wall ports, and heat-recovery central ventilation (HRV). HRV's have a higher initial cost than the other systems but they are the only ones that save energy. Homeowners are given guidelines for choosing the system best suited for their homes in terms of efficiency and payback period.

  20. A central microprocessor controlled electrical storage heating system

    NASA Astrophysics Data System (ADS)

    Horstmann, H.

    1980-12-01

    The use of a microprocessor to control the reloading of electrical storage heaters not only during the night, but whenever the electrical grid is cycled down, was tested. The test setup, used to control a total of about 10 MW installed storage heating in 96 dwellings, is described. It is demonstrated that additional consumers can be connected to the system without demand for more power stations.

  1. REACTOR

    DOEpatents

    Spitzer, L. Jr.

    1962-01-01

    The system conteraplates ohmically heating a gas to high temperatures such as are useful in thermonuclear reactors of the stellarator class. To this end the gas is ionized and an electric current is applied to the ionized gas ohmically to heat the gas while the ionized gas is confined to a central portion of a reaction chamber. Additionally, means are provided for pumping impurities from the gas and for further heating the gas. (AEC)

  2. Response of the Land-Atmosphere System Over North-Central Oklahoma During the 2017 Eclipse

    NASA Astrophysics Data System (ADS)

    Turner, D. D.; Wulfmeyer, V.; Behrendt, A.; Bonin, T. A.; Choukulkar, A.; Newsom, R. K.; Brewer, W. A.; Cook, D. R.

    2018-02-01

    On 21 August 2017, a solar eclipse occurred over the continental United States resulting in a rapid reduction and subsequent increase of solar radiation over a large region of the country. The eclipse's effect on the land-atmosphere system is documented in unprecedented detail using a unique array of sensors deployed at three sites in north-central Oklahoma. The observations showed that turbulent fluxes of heat and momentum at the surface responded quickly to the change in solar radiation. The decrease in the sensible heat flux resulted in a decrease in the air temperature below 200 m, and a large decrease in turbulent motions throughout the boundary layer. Furthermore, the turbulent mixing in the boundary layer lagged behind the change in the surface fluxes, and this lag depended on the height above the surface. The turbulent motions increased and the convective boundary layer was reestablished as the sensible heat flux recovered.

  3. The "Public" University: Recalling Higher Education's Democratic Purpose

    ERIC Educational Resources Information Center

    Benson, Michael T.; Boyd, Hal R.

    2015-01-01

    The modern university has been called, "a series of separate schools and departments held together by a central heating system," and, in a play on this line, "a series of individual faculty entrepreneurs held together by a common grievance over parking." Whether parking, heating, or, more probable today, WiFi, these…

  4. System integration of marketable subsystems. [for residential solar heating and cooling

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Progress is reported in the following areas: systems integration of marketable subsystems; development, design, and building of site data acquisition subsystems; development and operation of the central data processing system; operation of the MSFC Solar Test Facility; and systems analysis.

  5. Potential for Hydrothermal Deposits in Large Martian Impact Craters

    NASA Astrophysics Data System (ADS)

    Thorsos, I. E.; Newsom, H. E.; Davies, A.

    2000-12-01

    Investigation of environments on Mars favorable for pre-biotic chemistry or primitive life is a goal of current strategy. Deposits left by hydrothermal systems on Mars are high priority targets. Impact craters larger than 50 km in diameter should have breached local aquifers and provided sufficient heat to power hydrothermal systems. The amount of heat in craters depends on the size of the melt sheet and uplifted basement forming the central peak. The volume of melt is estimated using scaling relationships (Cintala & Grieve, 1998). The central uplift originates below the transient crater cavity and has a stratigraphic uplift of 1/10 the final crater diameter (Melosh & Ivanov, 1999). The central uplift's temperature with depth profile is estimated using a cylindrical "plug" model and adding the enthalpy profile at the time of maximum impactor penetration (O'Keefe & Ahrens, 1994) to the ambient thermal gradient. The heat from the two sources is estimated over a range of crater diameters. The next phase of this work is to model the longevity and extent of the hydrothermal systems. Cintala, H. J. & R. A. F. Grieve, Meteor. and Plan. Sci. 33, 889-912, 1998. Melosh, H. J. & B. A. Ivanov, Annual Rev. Earth Planet. Sci., 385-415, 1999. O'Keefe, J. D. & T. J. Ahrens, Geol. Soc. Amer. Spec. Paper 293, 103-109, 1994.

  6. Dynamic conversion of solar generated heat to electricity

    NASA Technical Reports Server (NTRS)

    Powell, J. C.; Fourakis, E.; Hammer, J. M.; Smith, G. A.; Grosskreutz, J. C.; Mcbride, E.

    1974-01-01

    The effort undertaken during this program led to the selection of the water-superheated steam (850 psig/900 F) crescent central receiver as the preferred concept from among 11 candidate systems across the technological spectrum of the dynamic conversion of solar generated heat to electricity. The solar power plant designs were investigated in the range of plant capacities from 100 to 1000 Mw(e). The investigations considered the impacts of plant size, collector design, feed-water temperature ratio, heat rejection equipment, ground cover, and location on solar power technical and economic feasibility. For the distributed receiver systems, the optimization studies showed that plant capacities less than 100 Mw(e) may be best. Although the size of central receiver concepts was not parametrically investigated, all indications are that the optimal plant capacity for central receiver systems will be in the range from 50 to 200 Mw(e). Solar thermal power plant site selection criteria and methodology were also established and used to evaluate potentially suitable sites. The result of this effort was to identify a site south of Inyokern, California, as typically suitable for a solar thermal power plant. The criteria used in the selection process included insolation and climatological characteristics, topography, and seismic history as well as water availability.

  7. Cold Climate and Retrofit Applications for Air-to-Air Heat Pumps

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

    Baxter, Van D

    2015-01-01

    Air source heat pumps (ASHP) including air-to-air ASHPs are easily applied to buildings almost anywhere for new construction as well as retrofits or renovations. They are widespread in milder climate regions but their use in cold regions is hampered due to low heating efficiency and capacity at cold outdoor temperatures. Retrofitting air-to-air ASHPs to existing buildings is relatively easy if the building already has an air distribution system. For buildings without such systems alternative approaches are necessary. Examples are ductless, minisplit heat pumps or central heat pumps coupled to small diameter, high velocity (SDHV) air distribution systems. This article presentsmore » two subjects: 1) a summary of R&D investigations aimed at improving the cold weather performance of ASHPs, and 2) a brief discussion of building retrofit options using air-to-air ASHP systems.« less

  8. A generalized analysis of solar space heating

    NASA Astrophysics Data System (ADS)

    Clark, J. A.

    A life-cycle model is developed for solar space heating within the United States. The model consists of an analytical relationship among five dimensionless parameters that include all pertinent technical, climatological, solar, operating and economic factors that influence the performance of a solar space heating system. An important optimum condition presented is the break-even metered cost of conventional fuel at which the cost of the solar system is equal to that of a conventional heating system. The effect of Federal (1980) and State (1979) income tax credits on these costs is determined. A parameter that includes both solar availability and solar system utilization is derived and plotted on a map of the U.S. This parameter shows the most favorable present locations for solar space heating application to be in the Central and Mountain States. The data employed are related to the rehabilitated solar data recently made available by the National Climatic Center.

  9. First heat flow density determinations from Southeastern Zaïre (Central Africa)

    NASA Astrophysics Data System (ADS)

    Sebagenzi, M. N.; Vasseur, G.; Louis, P.

    1993-05-01

    First heat flow density determinations from southeastern Zaïre are presented. Sites are located in the late Proterozoic metasedimentary cover of the Pan-African belt (600 Ma.). For each individual boreholes, heat flow ranges between 48 and 72 mWm -2. The average value of 62 mW m -2 for the sites is similar to that of 66 mW m -2 observed in Zambia. Both values are higher than what is expected for Pan-African terranes. These heat flow determinations in Shaba province of southeastern Zaïre, together with gravity and seismological observations, support the hypothesis of lithospheric thinning for this area. As already suggested for Zambia, this lithospheric thinning may be associated with a southwestern extension of the East African Rift System from Tanganyika across the central African plateau.

  10. Case Study: Fuel Cells Provide Combined Heat and Power at Verizon's Garden City Central Office

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

    None

    2010-12-01

    This case study describes how Verizon's Central Office in Garden City, NY, installed a 1.4-MW phosphoric acid fuel cell system as an alternative solution to bolster electric reliability, optimize the company's energy use, and reduce costs in an environmentally responsible manner.

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

    A new generation of central, ducted variable-capacity heat pump systems has come on the market, promising very high cooling and heating efficiency. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they vary their cooling and heating output over a wide range (approximately 40 to 118% of nominal full capacity); thus, staying 'on' for 60% to 100% more hours per day compared to fixed-capacity systems. Current Phase 4 experiments in an instrumented lab home with simulated occupancy evaluate the impact of duct R-value enhancement on the overall operating efficiency of the variable-capacity systemmore » compared to the fixed-capacity system.« less

  12. Multifamily Individual Heating and Ventilation Systems, Lawrence, Massachusetts (Fact Sheet)

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

    Not Available

    The conversion of an older Massachusetts building into condominiums illustrates a safe, durable, and cost-effective solution for heating and ventilation systems that can potentially benefit millions of multifamily buildings. Merrimack Valley Habitat for Humanity (MVHfH) partnered with U.S. Department of Energy Building America team Building Science Corporation (BSC) to provide high performance affordable housing for 10 families in the retrofit of an existing mass masonry building (a former convent). The original ventilation design for the project was provided by a local engineer and consisted of a single large heat recovery ventilator (HRV) located in a mechanical room in the basementmore » with a centralized duct system providing supply air to the main living space and exhausting stale air from the single bathroom in each apartment. This design was deemed to be far too costly to install and operate for several reasons: the large central HRV was oversized and the specified flows to each apartment were much higher than the ASHRAE 62.2 rate; an extensive system of ductwork, smoke and fire dampers, and duct chases were specified; ductwork required a significant area of dropped ceilings; and the system lacked individual ventilation control in the apartments« less

  13. Energy Supply Options for Modernizing Army Heating Systems

    DTIC Science & Technology

    1999-01-01

    Army Regulation (AR) 420-49, Heating, Energy Selection and Fuel Storage, Distribution, and Dispens- ing Systems and Technical Manual (TM) 5-650...analysis. 26 USACERL TR 99/23 HEATMAP uses the AutoLISP program in AutoCAD to take the graphical input to populate a Microsoft® Access database in...of 1992, Subtitle F, Federal Agency Energy Man- agement. Technical Manual (TM) 5-650, Repairs and Utilities: Central Boiler Plants (HQDA, 13 October

  14. Heat transfer unit and method for prefabricated vessel

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

    Tamburello, David A.; Kesterson, Matthew R; Hardy, Bruce J.

    Vessel assemblies, heat transfer units for prefabricated vessels, and methods for heat transfer prefabricated vessel are provided. A heat transfer unit includes a central rod, and a plurality of peripheral rods surrounding the central rod and connected to the central rod. The plurality of peripheral rods are movable between a first collapsed position and a second bowed position, wherein in the second bowed position a midpoint of each of the plurality of peripheral rods is spaced from the central rod relative to in the first position. The heat transfer unit further includes a heat transfer element connected to one ofmore » the plurality of peripheral rods.« less

  15. Building America Case Study: Impact of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps, Cocoa, Florida

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

    C. Withers, J. Cummings, B. Nigusse, E. Martin

    A new generation of central, ducted variable-capacity heat pump systems has come on the market, promising very high cooling and heating efficiency. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they vary their cooling and heating output over a wide range (approximately 40 to 118% of nominal full capacity); thus, staying 'on' for 60% to 100% more hours per day compared to fixed-capacity systems. Current Phase 4 experiments in an instrumented lab home with simulated occupancy evaluate the impact of duct R-value enhancement on the overall operating efficiency of the variable-capacity systemmore » compared to the fixed-capacity system.« less

  16. Combined microwave heating and surface cooling of the cornea.

    PubMed

    Trembly, B S; Keates, R H

    1991-01-01

    We investigated a nonsurgical means of reshaping the cornea to correct hyperopia, keratoconus, or myopia. The object was to heat the central stroma of the cornea to the shrinkage temperature of collagen, 55-58 degrees C. The heating device was an open-ended, coaxial, near-field applicator driven at 2450 MHz; it incorporates cooling of the cornea surface by flow of saline. We investigated the system theoretically by computing the 2-D, axisymmetric temperature distribution with the finite element method. We investigated the system experimentally by heating excised steer corneas. Histology showed the system could shrink the stroma to a depth of 0.6 mm while sparing the epithelium in 75% of cases; the diameter of shrinkage was 1.3 mm. Theory predicted a significantly deeper and narrower region of shrinkage than was observed.

  17. Expression of the Hsp23 chaperone during Drosophila embryogenesis: association to distinct neural and glial lineages

    PubMed Central

    Michaud, Sébastien; Tanguay, Robert M

    2003-01-01

    Background In addition to their strong induction following stress, small heat shock proteins (Hsp) are also expressed during development in a wide variety of organisms. However, the precise identity of cell(s) expressing these proteins and the functional contribution of small heat shock proteins in such developmental context remain to be determined. The present study provides a detailed description of the Drosophila small heat shock protein Hsp23 expression pattern during embryogenesis and evaluates its functional contribution to central nervous system development. Results Throughout embryogenesis, Hsp23 is expressed in a stage-specific manner by a restricted number of neuronal and glial lineages of the central nervous system. Hsp23 is also detected in the amnioserosa and within a single lateral chordotonal organ. Its expression within the MP2 lineage does not require the presence of a functional midline nor the activity of the Notch signaling pathway. Transactivation assays demonstrate that transcription factors implicated in the differentiation of the midline also regulate hsp23 promoter activity. Phenotypic analysis of a transgenic line exhibiting loss of Hsp23 expression in the central nervous system suggests that Hsp23 is not required for development and function of this tissue. Likewise, its overexpression does not cause deleterious effects, as development remains unaffected. Conclusions Based on the presented data, we suggest that the tightly regulated developmental expression of Hsp23 is not actively involved in cell differentiation and central nervous system development per se but rather reflects a putative role in preventive "pre-stress" neuroprotection or in non-vital process(es) common to the identified cell lineages. PMID:14617383

  18. Ecrh on Asdex Upgrade - System Extension, New Modes of Operation, Plasma Physics Results

    NASA Astrophysics Data System (ADS)

    Stober, J.; Wagner, D.; Giannone, L.; Leuterer, F.; Marascheck, M.; Mlynek, A.; Monaco, F.; Münich, M.; Poli, E.; Reich, M.; Schmid-Lorch, D.; Schütz, H.; Schweinzer, J.; Treutterer, W.; Zohm, H.; Meier, A.; Scherer, Th.; Flamm, J.; Thumm, M.; Höhnle, H.; Kasparek, W.; Stroth, U.; Chirkov, A. V.; Denisov, G. G.; Litvak, A.; Malygin, S. A.; Myasnikov, V. E.; Nichiporenko, V. O.; Popov, L. G.; Soluyanova, E. A.; Tai, E. M.

    2011-02-01

    The ECRH system at ASDEX Upgrade is currently extended from 1.6 MW to 5 MW. The extension so far consists of 2-frequency units, which use single diamond-disk vacuum-windows to transmit power at the natural resonances of these disks (105 & 140 GHz). For the last unit of this extension two additional intermediate non-resonant frequencies are foreseen, requiring new window concepts. For the torus a polarisation-independent double-disk window has been developed. For the gyrotron a grooved diamond disk is actually favoured, for which the grooved surfaces act as anti-reflective coating. Since ASDEX Upgrade operates with completely W-covered plasma facing components, central ECRH is often applied to suppresses W-accumulation in the plasma center. In order to extend the operational range for central ECRH, X3- and O2-heating schemes were developed. Both are characterized by incomplete single-path absorption. For X3 heating, the X2 resonance at the pedestal on the high field side is used as a 'beam-dump', for the O2 scheme a specific reflector tile on the inner heat shield enforces a second path through the plasma center. The geometry for NTM control had to be modified to allow simultaneous central heating. In real-time the ECRH position can be determined either by ray-tracing based on real-time equilibria and density profiles or from ECE for modulated ECRH power. Fast real-time ECE also allows to determine the NTM position. Further major physics applications of the system are summarized.

  19. A thermodynamic analysis of a novel bidirectional district heating and cooling network

    DOE PAGES

    Zarin Pass, R.; Wetter, M.; Piette, M. A.

    2017-11-29

    In this study, we evaluate an ambient, bidirectional thermal network, which uses a single circuit for both district heating and cooling. When in net more cooling is needed than heating, the system circulates from a central plant in one direction. When more heating is needed, the system circulates in the opposite direction. A large benefit of this design is that buildings can recover waste heat from each other directly. We analyze the thermodynamic performance of the bidirectional system. Because the bidirectional system represents the state-of-the-art in design for district systems, its peak energy efficiency represents an upper bound on themore » thermal performance of any district heating and cooling system. However, because any network has mechanical and thermal distribution losses, we develop a diversity criterion to understand when the bidirectional system may be a more energy-efficient alternative to modern individual-building systems. We show that a simple model of a low-density, high-distribution loss network is more efficient than aggregated individual buildings if there is at least 1 unit of cooling energy per 5.7 units of simultaneous heating energy (or vice versa). We apply this criterion to reference building profiles in three cities to look for promising clusters.« less

  20. A thermodynamic analysis of a novel bidirectional district heating and cooling network

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

    Zarin Pass, R.; Wetter, M.; Piette, M. A.

    In this study, we evaluate an ambient, bidirectional thermal network, which uses a single circuit for both district heating and cooling. When in net more cooling is needed than heating, the system circulates from a central plant in one direction. When more heating is needed, the system circulates in the opposite direction. A large benefit of this design is that buildings can recover waste heat from each other directly. We analyze the thermodynamic performance of the bidirectional system. Because the bidirectional system represents the state-of-the-art in design for district systems, its peak energy efficiency represents an upper bound on themore » thermal performance of any district heating and cooling system. However, because any network has mechanical and thermal distribution losses, we develop a diversity criterion to understand when the bidirectional system may be a more energy-efficient alternative to modern individual-building systems. We show that a simple model of a low-density, high-distribution loss network is more efficient than aggregated individual buildings if there is at least 1 unit of cooling energy per 5.7 units of simultaneous heating energy (or vice versa). We apply this criterion to reference building profiles in three cities to look for promising clusters.« less

  1. Heat-flow properties of systems with alternate masses or alternate on-site potentials.

    PubMed

    Pereira, Emmanuel; Santana, Leonardo M; Ávila, Ricardo

    2011-07-01

    We address a central issue of phononics: the search of properties or mechanisms to manage the heat flow in reliable materials. We analytically study standard and simple systems modeling the heat flow in solids, namely, the harmonic, self-consistent harmonic and also anharmonic chains of oscillators, and we show an interesting insulating effect: While in the homogeneous models the heat flow decays as the inverse of the particle mass, in the chain with alternate masses it decays as the inverse of the square of the mass difference, that is, it decays essentially as the mass ratio (between the smaller and the larger one) for a large mass difference. A similar effect holds if we alternate on-site potentials instead of particle masses. The existence of such behavior in these different systems, including anharmonic models, indicates that it is a ubiquitous phenomenon with applications in the heat flow control.

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

    Tamburello, David A.; McWilliams, Anthony J.; Hardy, Bruce J.

    Vessel assemblies, heat transfer units for prefabricated vessels, and methods for heat transfer prefabricated vessel are provided. A heat transfer unit includes a central rod, and a plurality of peripheral rods surrounding the central rod and connected to the central rod. The plurality of peripheral rods are movable between a first collapsed position and a second bowed position, wherein in the second bowed position a midpoint of each of the plurality of peripheral rods is spaced from the central rod relative to in the first position. The heat transfer unit further includes a heat transfer element connected to one ofmore » the plurality of peripheral rods.« less

  3. A hemicyanine based ratiometric fluorescence probe for mapping lysosomal pH during heat stroke in living cells.

    PubMed

    Wu, Luling; Wang, Yang; James, Tony D; Jia, Nengqin; Huang, Chusen

    2018-05-29

    Heat stroke is a lethal condition which can cause dysfunction in the central nervous system, multi-organ damage and even death. However, there is still limited knowledge of the detailed mechanism about the roles of lysosomes in heat stroke due to lack of effective tools. Herein, we introduce our previously developed hemicyanine with a large D-π-A structure as the key fluorophore to develop a new fluorescent probe (CPY) for ratiometric mapping of lysosomal pH changes in live cells under a heat shock stimulus.

  4. Application of remote thermal scanning to the NASA energy conservation program

    NASA Technical Reports Server (NTRS)

    Bowman, R. L.; Jack, J. R.

    1977-01-01

    Airborne thermal scans of all NASA centers were made during 1975 and 1976. The remotely sensed data were used to identify a variety of heat losses, including those from building roofs and central heating system distribution lines. Thermal imagery from several NASA centers is presented to demonstrate the capability of detecting these heat losses remotely. Many heat loss areas located by the scan data were verified by ground surveys. At this point, at least for such energy-intensive areas, thermal scanning is an excellent means of detecting many possible energy losses.

  5. Response of the Land-Atmosphere System Over North-Central Oklahoma During the 2017 Eclipse

    DOE PAGES

    Turner, D. D.; Wulfmeyer, V.; Behrendt, A.; ...

    2018-02-05

    On 21 August 2017, a solar eclipse occurred over the continental United States resulting in a rapid reduction and subsequent increase of solar radiation over a large region of the country. The eclipse’s effect on the land-atmosphere system is documented in unprecedented detail using a unique array of sensors deployed at three sites in north-central Oklahoma. The observations showed that turbulent fluxes of heat and momentum at the surface responded quickly to the change in solar radiation. The decrease in the sensible heat flux resulted in a decrease in the air temperature below 200 m, and a large decrease inmore » turbulent motions throughout the boundary layer. Furthermore, the turbulent mixing in the boundary layer lagged behind the change in the surface fluxes, and this lag depended on the height above the surface. The turbulent motions increased and the convective boundary layer was reestablished as the sensible heat flux recovered.« less

  6. Response of the Land-Atmosphere System Over North-Central Oklahoma During the 2017 Eclipse

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

    Turner, D. D.; Wulfmeyer, V.; Behrendt, A.

    On 21 August 2017, a solar eclipse occurred over the continental United States resulting in a rapid reduction and subsequent increase of solar radiation over a large region of the country. The eclipse’s effect on the land-atmosphere system is documented in unprecedented detail using a unique array of sensors deployed at three sites in north-central Oklahoma. The observations showed that turbulent fluxes of heat and momentum at the surface responded quickly to the change in solar radiation. The decrease in the sensible heat flux resulted in a decrease in the air temperature below 200 m, and a large decrease inmore » turbulent motions throughout the boundary layer. Furthermore, the turbulent mixing in the boundary layer lagged behind the change in the surface fluxes, and this lag depended on the height above the surface. The turbulent motions increased and the convective boundary layer was reestablished as the sensible heat flux recovered.« less

  7. Evaluation of a low cost wireless heat ratio method system for measuring transpiration

    NASA Astrophysics Data System (ADS)

    Eiriksson, D.; Boyer, B.; Aishlin, P. S.; Bowling, D. R.

    2016-12-01

    For decades, environmental measurements in remote locations have consisted of sensors hard wired to loggers that send data to central servers via radio, satellite, or cellular telemetry. This model of data collection is effective when all sensors are located in close proximity to the central data logger, such as on a weather station. Frequently, however, in order to adequately capture the spatial heterogeneity associated with environmental processes (e.g., transpiration, soil moisture, or snow depth), it is necessary to install many sensors 10's to 100's of meters from a central data logging station. This presents a practical and financial obstacle when considering the cost of cabling and conduit, in addition to the potential data collection and data quality problems associated with long cable runs. We offer a solution to this persistent challenge with a hybrid datalogging system that combines the power and reliability of Campbell Scientific logging and telemetry equipment with low cost Xbee radios and Arduino based data logging platforms. To evaluate the promise of this hybrid datalogging concept we developed a new generation of low cost, homemade heat ratio sapflux sensors and tested them at a forested site in the Wasatch Mountains, near Salt Lake City, Utah. We present data from this test site, heat ratio method sensor construction details, and example code that merges the capabilities of Arduino and Campbell Scientific datalogging systems.

  8. An Overview of Atmospheric Fluidized Bed Combustion Systems as Applied to Army Scale Central Heat Plants

    DTIC Science & Technology

    1992-11-01

    heat transfer surfaces located in the path of the exiting combustion gases generate additional steam. Flue gas particulates entrained in the combustion...anid the overall heat transfer surface anid boiler volume can be reduced. After the hot flue gas exits thie bed, it enters the external COnv.ctfion...rates, underfeed stoker fired combustors emit little smoke, and only a low concentration of particulates entrained in the flue gas . Under these

  9. Wastewater recycling and heat reclamation at the Red Lion Central Laundry, Portland, Oregon

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

    Garlick, T.F.; Halverson, M.A.; Ledbetter, M.R.

    1996-09-01

    This report discusses water, energy, and cost savings that can be achieved in a commercial laundry through the use of a wastewater recycling and heat recovery system. Cost savings are achieved through reductions in water use, reduction in sewage charges, reductions in water heating energy, and potential reductions in water treatment chemicals. This report provides an economic analysis of the impact of capital investment, daily consumption, and local utility rates on the payback period.

  10. LSU Slashes Energy Use

    ERIC Educational Resources Information Center

    Collier, Herbert I.

    1978-01-01

    Energy conservation programs at Louisiana State University reduced energy use 23 percent. The programs involved computer controlled power management systems, adjustment of building temperatures and lighting levels to prescribed standards, consolidation of night classes, centralization of chilled water systems, and manual monitoring of heating and…

  11. Human psychophysics and rodent spinal neurones exhibit peripheral and central mechanisms of inflammatory pain in the UVB and UVB heat rekindling models.

    PubMed

    O'Neill, Jessica; Sikandar, Shafaq; McMahon, Stephen B; Dickenson, Anthony H

    2015-09-01

    Translational research is key to bridging the gaps between preclinical findings and the patients, and a translational model of inflammatory pain will ideally induce both peripheral and central sensitisation, more effectively mimicking clinical pathophysiology in some chronic inflammatory conditions. We conducted a parallel investigation of two models of inflammatory pain, using ultraviolet B (UVB) irradiation alone and UVB irradiation with heat rekindling. We used rodent electrophysiology and human quantitative sensory testing to characterise nociceptive processing in the peripheral and central nervous systems in both models. In both species, UVB irradiation produces peripheral sensitisation measured as augmented evoked activity of rat dorsal horn neurones and increased perceptual responses of human subjects to mechanical and thermal stimuli. In both species, UVB with heat rekindling produces central sensitisation. UVB irradiation alone and UVB with heat rekindling are translational models of inflammation that produce peripheral and central sensitisation, respectively. The predictive value of laboratory models for human pain processing is crucial for improving translational research. The discrepancy between peripheral and central mechanisms of pain is an important consideration for drug targets, and here we describe two models of inflammatory pain that involve ultraviolet B (UVB) irradiation, which can employ peripheral and central sensitisation to produce mechanical and thermal hyperalgesia in rats and humans. We use electrophysiology in rats to measure the mechanically- and thermally-evoked activity of rat spinal neurones and quantitative sensory testing to assess human psychophysical responses to mechanical and thermal stimulation in a model of UVB irradiation and in a model of UVB irradiation with heat rekindling. Our results demonstrate peripheral sensitisation in both species driven by UVB irradiation, with a clear mechanical and thermal hypersensitivity of rat dorsal horn neurones and enhanced perceptual responses of human subjects to both mechanical and thermal stimulation. Additional heat rekindling produces markers of central sensitisation in both species, including enhanced receptive field sizes. Importantly, we also showed a correlation in the evoked activity of rat spinal neurones to human thermal pain thresholds. The parallel results in rats and humans validate the translational use of both models and the potential for such models for preclinical assessment of prospective analgesics in inflammatory pain states. © 2015 The Authors. The Journal of Physiology © 2015 The Physiological Society.

  12. Geothermal System Extensions

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

    Gunnerson, Jon; Pardy, James J.

    This material is based upon work supported by the Department of Energy under Award Number DE-EE0000318. The City of Boise operates and maintains the nation’s largest geothermal heating district. Today, 91 buildings are connected, providing space heating to over 5.5 million square feet, domestic water heating, laundry and pool heating, sidewalk snowmelt and other related uses. Approximately 300 million gallons of 177°F geothermal water is pumped annually to buildings and institutions located in downtown Boise. The closed loop system returns all used geothermal water back into the aquifer after heat has been removed via an Injection Well. Water injected backmore » into the aquifer has an average temperature of 115°F. This project expanded the Boise Geothermal Heating District (Geothermal System) to bring geothermal energy to the campus of Boise State University and to the Central Addition Eco-District. In addition, this project also improved the overall system’s reliability and increased the hydraulic capacity.« less

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

    PubMed

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

    1987-01-01

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

  14. A generalized analysis of solar space heating in the United States

    NASA Astrophysics Data System (ADS)

    Clark, J. A.

    A life-cycle model is developed for solar space heating within the United States that is based on the solar design data from the Los Alamos Scientific Laboratory. The model consists of an analytical relationship among five dimensionless parameters that include all pertinent technical, climatological, solar, operating and economic factors that influence the performance of a Solar Space Heating System. An important optimum condition presented is the 'Breakeven' metered cost of conventional fuel at which the cost of the solar system is equal to that of a conventional heating system. The effect of Federal (1980) and State (1979) income tax credits on these costs is determined. A parameter that includes both solar availability and solar system utilization is derived and plotted on a map of the U.S. This parameter shows the most favorable present locations for solar space heating application to be in the Central and Mountain States. The data employed are related to the rehabilitated solar data recently made available by the National Climatic Center (SOLMET).

  15. Temperature offset control system

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

    Fried, M.

    1987-07-28

    This patent describes a temperature offset control system for controlling the operation of both heating and air conditioning systems simultaneously contained within the same premises each of which is set by local thermostats to operate at an appropriate temperature, the offset control system comprising: a central control station having means for presetting an offset temperature range, means for sensing the temperature at a central location, means for comparing the sensed temperature with the offset temperature range, means responsive to the comparison for producing a control signal indicative of whether the sensed temperature is within the offset temperature range or beyondmore » the offset temperature range, and means for transmitting the control signal onto the standard energy lines servicing the premises; and a receiving station respectively associated with each heating and air conditioning system, the receiving stations each comprising means for receiving the same transmitted control signal from the energy lines, and switch means for controlling the energization of the respective system in response to the received control signal. The heating systems and associated local thermostat are disabled by the control signal when the control signal originates from a sensed temperature above the lower end of the offset temperature range. The air conditioning systems and associated thermostats are disabled by the same control signal when the control signal originates from a sensed temperature below the upper end of the offset temperature range.« less

  16. Case Study for the ARRA-Funded Ground Source Heat Pump Demonstration at Ball State University

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

    Im, Piljae; Liu, Xiaobing; Henderson, Jr., Hugh

    With funding provided by the American Recovery and Reinvestment Act (ARRA), 26 ground-source heat pump (GSHP) projects were competitively selected in 2009 to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. One of the selected demonstration projects is a district central GSHP system installed at Ball State University (BSU) in Muncie, IN. Prior to implementing the district GSHP system, 47 major buildings in BSU were served by a central steam plant with four coal-fired and three natural-gas-fired steam boilers. Cooling was provided by five water-cooled centrifugal chillers at the District Energy Station Southmore » (DESS). The new district GSHP system replaced the existing coal-fired steam boilers and conventional water-cooled chillers. It uses ground-coupled heat recovery (HR) chillers to meet the simultaneous heating and cooling demands of the campus. The actual performance of the GSHP system was analyzed based on available measured data from August 2015 through July 2016, construction drawings, maintenance records, personal communications, and construction costs. Since Phase 1 was funded in part by the ARRA grant, it is the focus of this case study. The annual energy consumption of the GSHP system was calculated based on the available measured data and other related information. It was compared with the performance of a baseline scenario— a conventional water-cooled chiller and natural-gas-fired boiler system, both of which meet the minimum energy efficiencies allowed by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE 90.1-2013). The comparison was made to determine source energy savings, energy cost savings, and CO2 emission reductions achieved by the GSHP system. A cost analysis was performed to evaluate the simple payback of the GSHP system. The following sections summarize the results of the analysis, the lessons learned, and recommendations for improvement in the operation of this district GSHP system.« less

  17. Technology Solutions Case Study: Advanced Boiler Load Monitoring Controls, Chicago, Illinois

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

    None

    2014-09-01

    Most of Chicago’s older multifamily housing stock is heated by centrally metered steam or hydronic systems. The cost of heat is typically absorbed into the owner’s operating cost and is then passed to tenants. Central boilers typically have long service lifetimes; the incentive for retrofit system efficiency upgrades is greater than equipment replacement for the efficiency-minded owner. System improvements as the “low-hanging fruit” are familiar, from improved pipe insulation to aftermarket controls such as outdoor temperature reset (OTR) or lead/lag controllers for sites with multiple boilers. Beyond these initial system efficiency upgrades are an emerging class of Advanced Load Monitoringmore » (ALM) aftermarket controllers that dynamically respond to the boiler load, with claims of 10% to 30% of fuel savings over a heating season. In this project, the Building America team Partnership for Advanced Residential Retrofit (PARR) installed and monitored an ALM aftermarket controller, the M2G from Greffen Systems, at two Chicago area multifamily buildings with existing OTR control. Results show that energy savings depend on the degree to which boilers are oversized for their load, represented by cycling rates. Also, savings vary over the heating season with cycling rates, with greater savings observed in shoulder months. Over the monitoring period, oversized boilers at one site showed reductions in cycling and energy consumption in line with prior laboratory studies, while less oversized boilers at another site showed muted savings.« less

  18. A Conceptual Design Study on the Application of Liquid Metal Heat Transfer Technology to the Solar Thermal Power Plant

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.; Robertson, C. S.; Ehde, C. L.; Divakaruni, S. M.; Stacy, L. E.

    1979-01-01

    Alkali metal heat transfer technology was used in the development of conceptual designs for the transport and storage of sensible and latent heat thermal energy in distributed concentrator, solar Stirling power conversion systems at a power level of 15 kWe per unit. Both liquid metal pumped loop and heat pipe thermal transport were considered; system configurations included: (1) an integrated, focal mounted sodium heat pipe solar receiver (HPSR) with latent heat thermal energy storage; (2) a liquid sodium pumped loop with the latent heat storage, Stirling engine-generator, pump and valves located on the back side of the concentrator; and (3) similar pumped loops serving several concentrators with more centralized power conversion and storage. The focus mounted HPSR was most efficient, lightest and lowest in estimated cost. Design confirmation testing indicated satisfactory performance at all angles of inclination of the primary heat pipes to be used in the solar receiver.

  19. Energy saving analysis on mine-water source heat pump in a residential district of Henan province, central China

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Duan, Huanlin; Chen, Aidong

    2018-02-01

    In this paper, the mine-water source heat pump system is proposed in residential buildings of a mining community. The coefficient of performance (COP) and the efficiency of exergy are analyzed. The results show that the COP and exergy efficiency of the mine-water source heat pump are improved, the exergy efficiency of mine-water source heat pump is more than 10% higher than that of the air source heat pump.The electric power conservation measure of “peak load shifting” is also emphasized in this article. It shows that itis a very considerable cost in the electric saving by adopting the trough period electricity to produce hot water. Due to the proper temperature of mine water, the mine-watersource heat pump unit is more efficient and stable in performance, which further shows the advantage of mine-water source heat pump in energy saving and environmental protection. It provides reference to the design of similar heat pump system as well.

  20. Mold Heating and Cooling Pump Package Operator Interface Controls Upgrade

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

    Josh A. Salmond

    2009-08-07

    The modernization of the Mold Heating and Cooling Pump Package Operator Interface (MHC PP OI) consisted of upgrading the antiquated single board computer with a proprietary operating system to off-the-shelf hardware and off-the-shelf software with customizable software options. The pump package is the machine interface between a central heating and cooling system that pumps heat transfer fluid through an injection or compression mold base on a local plastic molding machine. The operator interface provides the intelligent means of controlling this pumping process. Strict temperature control of a mold allows the production of high quality parts with tight tolerances and lowmore » residual stresses. The products fabricated are used on multiple programs.« less

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

    NASA Astrophysics Data System (ADS)

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

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

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

    NASA Technical Reports Server (NTRS)

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

    1987-01-01

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

  3. Altered Pain Sensitivity in Elderly Women with Chronic Neck Pain

    PubMed Central

    Uthaikhup, Sureeporn; Prasert, Romchat; Paungmali, Aatit; Boontha, Kritsana

    2015-01-01

    Background Age-related changes occur in both the peripheral and central nervous system, yet little is known about the influence of chronic pain on pain sensitivity in older persons. The aim of this study was to investigate pain sensitivity in elders with chronic neck pain compared to healthy elders. Methods Thirty elderly women with chronic neck pain and 30 controls were recruited. Measures of pain sensitivity included pressure pain thresholds, heat/cold pain thresholds and suprathreshold heat pain responses. The pain measures were assessed over the cervical spine and at a remote site, the tibialis anterior muscle. Results Elders with chronic neck pain had lower pressure pain threshold over the articular pillar of C5-C6 and decreased cold pain thresholds over the cervical spine and tibialis anterior muscle when compared with controls (p < 0.05). There were no between group differences in heat pain thresholds and suprathreshold heat pain responses (p > 0.05). Conclusion The presence of pain hypersensitivity in elderly women with chronic neck pain appears to be dependent on types of painful stimuli. This may reflect changes in the peripheral and central nervous system with age. PMID:26039149

  4. Eddy Correlation Flux Measurement System (ECOR) Handbook

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

    Cook, DR

    2011-01-31

    The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.

  5. Fluid-cooled heat sink with improved fin areas and efficiencies for use in cooling various devices

    DOEpatents

    Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth; Narumanchi, Sreekant

    2015-04-21

    The disclosure provides a fluid-cooled heat sink having a heat transfer base and a plurality of heat transfer fins in thermal communication with the heat transfer base, where the heat transfer base and the heat transfer fins form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop of the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.

  6. 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.

  7. Performance of a Heating Block System Designed for Studying the Heat Resistance of Bacteria in Foods

    NASA Astrophysics Data System (ADS)

    Kou, Xiao-Xi; Li, Rui; Hou, Li-Xia; Huang, Zhi; Ling, Bo; Wang, Shao-Jin

    2016-07-01

    Knowledge of bacteria’s heat resistance is essential for developing effective thermal treatments. Choosing an appropriate test method is important to accurately determine bacteria’s heat resistances. Although being a major factor to influence the thermo-tolerance of bacteria, the heating rate in samples cannot be controlled in water or oil bath methods due to main dependence on sample’s thermal properties. A heating block system (HBS) was designed to regulate the heating rates in liquid, semi-solid and solid foods using a temperature controller. Distilled water, apple juice, mashed potato, almond powder and beef were selected to evaluate the HBS’s performance by experiment and computer simulation. The results showed that the heating rates of 1, 5 and 10 °C/min with final set-point temperatures and holding times could be easily and precisely achieved in five selected food materials. A good agreement in sample central temperature profiles was obtained under various heating rates between experiment and simulation. The experimental and simulated results showed that the HBS could provide a sufficiently uniform heating environment in food samples. The effect of heating rate on bacterial thermal resistance was evaluated with the HBS. The system may hold potential applications for rapid and accurate assessments of bacteria’s thermo-tolerances.

  8. Heat Transfer Phenomena in Concentrating Solar Power Systems.

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

    Armijo, Kenneth Miguel; Shinde, Subhash L.

    Concentrating solar power (CSP) utilizes solar thermal energy to drive a thermal power cycle for the generation of electricity. CSP systems are facilitated as large, centralized power plants , such as power towers and trough systems, to take advantage of ec onomies of scale through dispatchable thermal energy storage, which is a principle advantage over other energy generation systems . Additionally, the combination of large solar concentration ratios with high solar conversion efficiencies provides a strong o pportunity of employment of specific power cycles such as the Brayton gas cycle that utilizes super critical fluids such as supercritical carbon dioxidemore » (s CO 2 ) , compared to other sola r - fossil hybrid power plants. A comprehensive thermal - fluids examination is provided by this work of various heat transfer phenomena evident in CSP technologies. These include sub - systems and heat transfer fundamental phenomena evident within CSP systems , which include s receivers, heat transfer fluids (HTFs), thermal storage me dia and system designs , thermodynamic power block systems/components, as well as high - temperature materials. This work provides literature reviews, trade studies, and phenomenological comparisons of heat transfer media (HTM) and components and systems, all for promotion of high performance and efficient CSP systems. In addition, f urther investigations are also conducted that provide advanced heat transfer modeling approaches for gas - particle receiver systems , as well as performance/efficiency enhancement re commendations, particularly for solarized supercritical power systems .« less

  9. Central control of body temperature

    PubMed Central

    Morrison, Shaun F.

    2016-01-01

    Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis. PMID:27239289

  10. Central control of body temperature.

    PubMed

    Morrison, Shaun F

    2016-01-01

    Central neural circuits orchestrate the behavioral and autonomic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response and behavioral states and in response to declining energy homeostasis. This review summarizes the central nervous system circuit mechanisms controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction regulating heat loss and shivering and brown adipose tissue for thermogenesis. The activation of these thermoeffectors is regulated by parallel but distinct efferent pathways within the central nervous system that share a common peripheral thermal sensory input. The model for the neural circuit mechanism underlying central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation, for elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation, and for the discovery of novel therapeutic approaches to modulating body temperature and energy homeostasis.

  11. 16 CFR Appendix I to Part 305 - Heating Performance and Cost for Central Air Conditioners

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... for Central Air Conditioners Manufacturer's rated heating capacity (Btu's/hr.) Range of HSPF's Low... 16 Commercial Practices 1 2014-01-01 2014-01-01 false Heating Performance and Cost for Central Air Conditioners I Appendix I to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC...

  12. Fluid-cooled heat sink for use in cooling various devices

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

    Bharathan, Desikan; Bennion, Kevin; Kelly, Kenneth

    The disclosure provides a fluid-cooled heat sink having a heat transfer base, a shroud, and a plurality of heat transfer fins in thermal communication with the heat transfer base and the shroud, where the heat transfer base, heat transfer fins, and the shroud form a central fluid channel through which a forced or free cooling fluid may flow. The heat transfer pins are arranged around the central fluid channel with a flow space provided between adjacent pins, allowing for some portion of the central fluid channel flow to divert through the flow space. The arrangement reduces the pressure drop ofmore » the flow through the fins, optimizes average heat transfer coefficients, reduces contact and fin-pin resistances, and reduces the physical footprint of the heat sink in an operating environment.« less

  13. Value impact assessment: A preliminary assessment of improvement opportunities at the Quantico Central Heating Plant

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

    Brambley, M.R.; Weakley, S.A.

    1990-09-01

    This report presents the results of a preliminary assessment of opportunities for improvement at the US Marine Corps (USMC) Quantico, Virginia, Central Heating Plant (CHP). This study is part of a program intended to provide the CHP staff with a computerized Artificial Intelligence (AI) decision support system that will assist in a more efficient, reliable, and safe operation of their plant. As part of the effort to provide the AI decision support system, a team of six scientists and engineers from the Pacific Northwest Laboratory (PNL) visited the plant to characterize the conditions and environment of the CHP. This assessmentmore » resulted in a list of potential performance improvement opportunities at the CHP. In this report, 12 of these opportunities are discussed and qualitatively analyzed. 70 refs., 7 figs., 6 tabs.« less

  14. Numerical simulation of hydrothermal circulation in the Cascade Range, north-central Oregon

    USGS Publications Warehouse

    Ingebritsen, S.E.; Paulson, K.M.

    1990-01-01

    Alternate conceptual models to explain near-surface heat-flow observations in the central Oregon Cascade Range involve (1) an extensive mid-crustal magmatic heat source underlying both the Quaternary arc and adjacent older rocks or (2) a narrower deep heat source which is flanked by a relatively shallow conductive heat-flow anomaly caused by regional ground-water flow (the lateral-flow model). Relative to the mid-crustal heat source model, the lateral-flow model suggests a more limited geothermal resource base, but a better-defined exploration target. We simulated ground-water flow and heat transport through two cross sections trending west from the Cascade range crest in order to explore the implications of the two models. The thermal input for the alternate conceptual models was simulated by varying the width and intensity of a basal heat-flow anomaly and, in some cases, by introducing shallower heat sources beneath the Quaternary arc. Near-surface observations in the Breitenbush Hot Springs area are most readily explained in terms of lateral heat transport by regional ground-water flow; however, the deep thermal structure still cannot be uniquely inferred. The sparser thermal data set from the McKenzie River area can be explained either in terms of deep regional ground-water flow or in terms of a conduction-dominated system, with ground-water flow essentially confined to Quaternary rocks and fault zones.

  15. Whole body heat stress increases motor cortical excitability and skill acquisition in humans

    PubMed Central

    Littmann, Andrew E.; Shields, Richard K.

    2015-01-01

    Objective Vigorous systemic exercise stimulates a cascade of molecular and cellular processes that enhance central nervous system (CNS) plasticity and performance. The influence of heat stress on CNS performance and learning is novel. We designed two experiments to determine whether passive heat stress 1) facilitated motor cortex excitability and 2) improved motor task acquisition compared to no heat stress. Methods Motor evoked potentials (MEPs) from the first dorsal interosseus (FDI) were collected before and after 30 minutes of heat stress at 73° C. A second cohort of subjects performed a motor learning task using the FDI either following heat or the no heat condition. Results Heat stress increased heart rate to 65% of age-predicted maximum. After heat, mean resting MEP amplitude increased 48% (P < 0.05). MEP stimulus-response amplitudes did not differ according to stimulus intensity. In the second experiment, heat stress caused a significant decrease in absolute and variable error (p < 0.05) during a novel movement task using the FDI. Conclusions Passive environmental heat stress 1) increases motor cortical excitability, and 2) enhances performance in a motor skill acquisition task. Significance Controlled heat stress may prime the CNS to enhance motor skill acquisition during rehabilitation. PMID:26616546

  16. Beam Energy Scan of Specific Heat Through Temperature Fluctuations in Heavy Ion Collisions

    NASA Astrophysics Data System (ADS)

    Basu, Sumit; Nandi, Basanta K.; Chatterjee, Sandeep; Chatterjee, Rupa; Nayak, Tapan

    2016-01-01

    Temperature fluctuations may have two distinct origins, first, quantum fluctuations that are initial state fluctuations, and second, thermodynamical fluctuations. We discuss a method of extracting the thermodynamic temperature from the mean transverse momentum of pions, by using controllable parameters such as centrality of the system, and range of the transverse momenta. Event-by-event fluctuations in global temperature over a large phase space provide the specific heat of the system. We present Beam Energy Scan of specific heat from data, AMPT and HRG model prediction. Experimental results from NA49, STAR, PHENIX, PHOBOS and ALICE are combined to obtain the specific heat as a function of beam energy. These results are compared to calculations from AMPT event generator, HRG model and lattice calculations, respectively.

  17. Central control of thermogenesis.

    PubMed

    Clapham, John C

    2012-07-01

    In mammals and birds, conservation of body heat at around 37 °C is vital to life. Thermogenesis is the production of this heat which can be obligatory, as in basal metabolic rate, or it can be facultative such as the response to cold. A complex regulatory system has evolved which senses environmental or core temperature and integrates this information in hypothalamic regions such as the preoptic area and dorsomedial hypothalamus. These areas then send the appropriate signals to generate and conserve heat (or dissipate it). In this review, the importance of the sympathetic nervous system is discussed in relation to its role in basal metabolic rate and adaptive thermogenesis with a particular emphasis to human obesity. The efferent sympathetic pathway does not uniformly act on all tissues; different tissues can receive different levels of sympathetic drive at the same time. This is an important concept in the discussion of the pharmacotherapy of obesity. Despite decades of work the medicine chest contains only one pill for the long term treatment of obesity, orlistat, a lipase inhibitor that prevents the absorption of lipid from the gut and is itself not systemically absorbed. The central controlling system for thermogenesis has many potential intervention points. Several drugs, previously marketed, awaiting approval or in the earlier stages of development may have a thermogenic effect via activation of the sympathetic nervous system at some point in the thermoregulatory circuit and are discussed in this review. If the balance is weighted to the "wrong" side there is the burden of increased cardiovascular risk while a shift to the "right" side, if possible, will afford a thermogenic benefit that is conducive to weight loss maintenance. This article is part of a Special Issue entitled 'Central Control Food Intake' Copyright © 2011 Elsevier Ltd. All rights reserved.

  18. 16 CFR Appendix I to Part 305 - Heating Performance and Cost for Central Air Conditioners

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... RULEâ) Pt. 305, App. I Appendix I to Part 305—Heating Performance and Cost for Central Air Conditioners... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Heating Performance and Cost for Central Air Conditioners I Appendix I to Part 305 Commercial Practices FEDERAL TRADE COMMISSION REGULATIONS UNDER SPECIFIC...

  19. Heat flow in Railroad Valley, Nevada and implications for geothermal resources in the south-central Great Basin

    USGS Publications Warehouse

    Williams, C.F.; Sass, J.H.

    2006-01-01

    The Great Basin is a province of high average heat flow (approximately 90 mW m-2), with higher values characteristic of some areas and relatively low heat flow (<60 mW m-2) characteristic of an area in south-central Nevada known as the Eureka Low. There is hydrologie and thermal evidence that the Eureka Low results from a relatively shallow, hydrologically controlled heat sink associated with interbasin water flow in the Paleozoic carbonate aquifers. Evaluating this hypothesis and investigating the thermal state of the Eureka Low at depth is a high priority for the US Geological Survey as it prepares a new national geothermal resource assessment. Part of this investigation is focused on Railroad Valley, the site of the largest petroleum reservoirs in Nevada and one of the few locations within the Eureka Low with a known geothermal system. Temperature and thermal conductivity data have been acquired from wells in Railroad Valley in order to determine heat flow in the basin. The results reveal a complex interaction of cooling due to shallow ground-water flow, relatively low (49 to 76 mW m-2) conductive heat flow at depth in most of the basin, and high (up to 234 mW m-2) heat flow associated with the 125??C geothermal system that encompasses the Bacon Flat and Grant Canyon oil fields. The presence of the Railroad Valley geothermal resource within the Eureka Low may be reflect the absence of deep ground-water flow sweeping heat out of the basin. If true, this suggests that other areas in the carbonate aquifer province may contain deep geothermal resources that are masked by ground-water flow.

  20. 16 CFR 305.12 - Labeling for central air conditioners, heat pumps, and furnaces.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... pumps, and furnaces. (a) Layout. All energy labels for central air conditioners, heat pumps, and... the end of this part illustrating the basic layout. All positioning, spacing, type sizes, and line... calculated for heating Region IV for the standardized design heating requirement nearest the capacity...

  1. 16 CFR 305.12 - Labeling for central air conditioners, heat pumps, and furnaces.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pumps, and furnaces. (a) Layout. All energy labels for central air conditioners, heat pumps, and... the end of this part illustrating the basic layout. All positioning, spacing, type sizes, and line... calculated for heating Region IV for the standardized design heating requirement nearest the capacity...

  2. 16 CFR 305.12 - Labeling for central air conditioners, heat pumps, and furnaces.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... pumps, and furnaces. (a) Layout. All energy labels for central air conditioners, heat pumps, and... end of this part illustrating the basic layout. All positioning, spacing, type sizes, and line widths... calculated for heating Region IV for the standardized design heating requirement nearest the capacity...

  3. 16 CFR 305.12 - Labeling for central air conditioners, heat pumps, and furnaces.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... pumps, and furnaces. (a) Layout. All energy labels for central air conditioners, heat pumps, and... the end of this part illustrating the basic layout. All positioning, spacing, type sizes, and line... calculated for heating Region IV for the standardized design heating requirement nearest the capacity...

  4. Development of Passive Fuel Cell Thermal Management Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian J.; Colozza, Anthony J.

    2010-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates that could conduct the heat, provide a sufficiently uniform temperature heat sink for each cell of the fuel cell stack, and be substantially lighter than the conventional thermal management approach. Tests were run with different materials to evaluate the design approach to a heat exchanger that could interface with the edges of the passive cooling plates. Measurements were made during fuel cell operation to determine the temperature of individual cooling plates and also to determine the temperature uniformity from one cooling plate to another.

  5. Energy cogeneration handbook

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

    Polimeros, G.

    1981-01-01

    Design criteria for central plants that facilitate energy conversion, utilization, and conservation, an evaluation of project alternatives and an examination of systems and their functions to achieve optimum overall design in the generation of heating, cooling, and electricity are presented.

  6. 77 FR 237 - Protection of Stratospheric Ozone: Adjustments to the Allowance System for Controlling HCFC...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-04

    ..., Heating, and Air-Conditioning Contractors (NAICS code 238220), including Central air-conditioning system and commercial refrigeration installation; HVAC contractors. This list is not intended to be... selecting its highest ODP- weighted consumption year from among the years 1994 through 1997. [[Page 241...

  7. Hydronic Heating Retrofits for Low-Rise Multifamily Buildings: Boiler Control Replacement and Monitoring

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

    Dentz, J.; Henderson, H.; Varshney, K.

    2014-09-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency. Efficient operation of themore » heating system faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68 degrees F) than day (73 degrees F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.« less

  8. Multifamily Heat Pump Water Heater Evaluation

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

    Hoeschele, M.; Weitzel, E.

    2017-03-03

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. Themore » TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.« less

  9. Multifamily Heat Pump Water Heater Evaluation

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

    Hoeschele, M.; Weitzel, E.

    2017-03-01

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16 month period were then used to validate a TRNSYS simulation model. Themore » TRNSYS model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.« less

  10. Combined installation of electric and heat supply for climatic conditions of Iraq

    NASA Astrophysics Data System (ADS)

    Kaisi, Osama Al; Sidenkov, D. V.

    2017-11-01

    Electricity, heating and cooling are the three main components that make up the energy consumption base in residential, commercial and public buildings around the world. Demand for energy and fuel costs are constantly growing. Combined cooling, heating and power generation or trigeneration can be a promising solution to such a problem, providing an efficient, reliable, flexible, competitive and less harmful alternative to existing heat and cold supply systems. In this paper, scheme of the tri-generation plant on non-aqueous working substances is considered as an installation of a locally centralized electro-heat and cold supply of a typical residential house in a hot climate. The scheme of the combined installation of electro-heat (cold) supply consisted of the vapor power plant and heat pump system on low-boiling working substance for local consumers under the climatic conditions of Iraq is presented. The possibility of using different working substances in the thermodynamic cycles of these units, which will provide better efficiency of such tri-generation systems is shown. The calculations of steam turbine cycles and heat pump part on the selected working substances are conducted. It is proposed to use heat exchangers of plate type as the main exchangers in the combined processing. The developed method of thermal-hydraulic calculation of heat exchangers implemented in MathCad, which allows to evaluate the efficiency of plants of this type using the ε - NTU method. For the selected working substances of the steam part the optimal temperature of heat supply to the steam generator is determined. The results of thermodynamic and technical-economic analysis of the application of various working substances in the “organic” Rankine cycle of the steam turbine unit and the heat pump system of the heat and cold supply system are presented.

  11. Advanced concepts and solutions for geothermal heating applied in Oradea, Romania

    NASA Astrophysics Data System (ADS)

    Antal, C.; Popa, F.; Mos, M.; Tigan, D.; Popa, B.; Muresan, V.

    2017-01-01

    Approximately 70% of the total population of Oradea benefits from centralized heating, about 55,000 apartments and 159,000 inhabitants are connected. The heating system of Oradea consists of: sources of thermal energy production (Combined heat and power (CHP) I Oradea and geothermal water heating plants); a transport network of heat; heat distribution network for heating and domestic hot water; substations, most of them equipped with worn and obsolete equipment. Recently, only a few heat exchangers were rehabilitated and electric valves were installed to control the water flow. After heat extraction, geothermal chilled waters from the Oradea area are: discharged into the sewer system of the city, paying a fee to the local water company which manages the city’s sewers; discharged into the small river Peta; or re-injected into the reservoir. In order to ensure environmental protection and a sustainable energy development in Oradea, renewable sources of energy have been promoted in recent years. In this respect, the creation of a new well for geothermal water re-injection into the reservoir limits any accidental thermal pollution of the environment, while ensuring the conservation properties of the aquifer by recharging with geothermal chilled water. The paper presents the achievements of such a project whose aim is to replace thermal energy obtained from coal with geothermal heating. The novelty consists in the fact that within the substation we will replace old heat exchangers, circulation pumps and valves with fully automated substations operating in parallel on both a geothermal system and on a primary heating system of a thermal plant.

  12. Economic analysis of wind-powered refrigeration cooling/water-heating systems in food processing. Final report

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

    Garling, W.S.; Harper, M.R.; Merchant-Geuder, L.

    1980-03-01

    Potential applications of wind energy include not only large central turbines that can be utilized by utilities, but also dispersed systems for farms and other applications. The US Departments of Energy (DOE) and Agriculture (USDA) currently are establishing the feasibility of wind energy use in applications where the energy can be used as available, or stored in a simple form. These applications include production of hot water for rural sanitation, heating and cooling of rural structures and products, drying agricultural products, and irrigation. This study, funded by USDA, analyzed the economic feasibility of wind power in refrigeration cooling and watermore » heating systems in food processing plants. Types of plants included were meat and poultry, dairy, fruit and vegetable, and aquaculture.« less

  13. Themis - A solar power station

    NASA Astrophysics Data System (ADS)

    Hillairet, J.

    The organization, goals, equipment, costs, and performance of the French Themis (Thermo-helio-electric-MW) project are outlined. The program was begun for both the domestic energy market and for export. The installation comprises a molten eutectic salt loop which receives heat from radiators situated in a central tower. The salt transfers the heat to water for steam generation of electricity. A storage tank holds enough molten salt to supply one day's reserve of power, 40 MWh. A field of heliostats directs the suns rays for an estimated 2400 hr/yr onto the central receiver aperture, while 11 additional parabolic concentrators provide sufficient heat to keep the salt reservoir at temperatures exceeding 200 C. In a test run of several months during the spring of 1982 the heliostats directed the sun's rays with an average efficiency of 75 percent, yielding 2.3 MW of power at a system efficiency of 20.5 percent in completely automatic operation.

  14. Dormitory renovation project reduces energy use by 69%

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

    Kokayko, M.J.

    1997-06-01

    Baldwin Hall is a three-story, 46,000 ft{sup 2} (4,273 m{sup 1}) dormitory on the campus of Allegheny College in Meadville, Pa. The building was originally built in the 1950s; an additional wing was added in the 1970s so that it has about 37,000 ft{sup 2} (3,437 m{sup 2}). The building contains approximately 100 double-occupancy student rooms; three common bathroom groups per floor; central study, lounge, and computer areas; and a laundry. Design for the renovation started in the winter of 1993; construction took place in the summer of 1994. The major goals of the renovation were: (1) to replace themore » entire building heating system (central boiler plant, distribution piping, and room heating terminals); (2) add a ventilation system within the building; (3) upgrade the building electrical system; (4) provide computer data cabling and cable TV wiring to each room; and, (5) improve room and hallway lighting and finishes.« less

  15. Demonstration of Passive Fuel Cell Thermal Management Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony; Wynne, Robert; Miller, Michael; Meyer, Al; Smith, William

    2012-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

  16. Development of Passive Fuel Cell Thermal Management Technology

    NASA Technical Reports Server (NTRS)

    Burke, Kenneth A.; Jakupca, Ian; Colozza, Anthony

    2011-01-01

    The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA exploration program. The passive thermal management system relies on heat conduction within the cooling plate to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack rather than using a pumped loop cooling system to convectively remove the heat. Using the passive approach eliminates the need for a coolant pump and other cooling loop components which reduces fuel cell system mass and improves overall system reliability. Previous analysis had identified that low density, ultra-high thermal conductivity materials would be needed for the cooling plates in order to achieve the desired reductions in mass and the highly uniform thermal heat sink for each cell within a fuel cell stack. A pyrolytic graphite material was identified and fabricated into a thin plate using different methods. Also a development project with Thermacore, Inc. resulted in a planar heat pipe. Thermal conductivity tests were done using these materials. The results indicated that lightweight passive fuel cell cooling is feasible.

  17. Workshop on Two-Phase Fluid Behavior in a Space Environment

    NASA Technical Reports Server (NTRS)

    Swanson, Theodore D. (Editor); Juhasz, AL (Editor); Long, W. Russ (Editor); Ottenstein, Laura (Editor)

    1989-01-01

    The Workshop was successful in achieving its main objective of identifying a large number of technical issues relating to the design of two-phase systems for space applications. The principal concern expressed was the need for verified analytical tools that will allow an engineer to confidently design a system to a known degree of accuracy. New and improved materials, for such applications as thermal storage and as heat transfer fluids, were also identified as major needs. In addition to these research efforts, a number of specific hardware needs were identified which will require development. These include heat pumps, low weight radiators, advanced heat pipes, stability enhancement devices, high heat flux evaporators, and liquid/vapor separators. Also identified was the need for a centralized source of reliable, up-to-date information on two-phase flow in a space environment.

  18. Thermoregulation in multiple sclerosis.

    PubMed

    Davis, Scott L; Wilson, Thad E; White, Andrea T; Frohman, Elliot M

    2010-11-01

    Multiple sclerosis (MS) is a progressive neurological disorder that disrupts axonal myelin in the central nervous system. Demyelination produces alterations in saltatory conduction, slowed conduction velocity, and a predisposition to conduction block. An estimated 60-80% of MS patients experience temporary worsening of clinical signs and neurological symptoms with heat exposure. Additionally, MS may produce impaired neural control of autonomic and endocrine functions. This review focuses on five main themes regarding the current understanding of thermoregulatory dysfunction in MS: 1) heat sensitivity; 2) central regulation of body temperature; 3) thermoregulatory effector responses; 4) heat-induced fatigue; and 5) countermeasures to improve or maintain function during thermal stress. Heat sensitivity in MS is related to the detrimental effects of increased temperature on action potential propagation in demyelinated axons, resulting in conduction slowing and/or block, which can be quantitatively characterized using precise measurements of ocular movements. MS lesions can also occur in areas of the brain responsible for the control and regulation of body temperature and thermoregulatory effector responses, resulting in impaired neural control of sudomotor pathways or neural-induced changes in eccrine sweat glands, as evidenced by observations of reduced sweating responses in MS patients. Fatigue during thermal stress is common in MS and results in decreased motor function and increased symptomatology likely due to impairments in central conduction. Although not comprehensive, some evidence exists concerning treatments (cooling, precooling, and pharmacological) for the MS patient to preserve function and decrease symptom worsening during heat stress.

  19. Whole body heat stress increases motor cortical excitability and skill acquisition in humans.

    PubMed

    Littmann, Andrew E; Shields, Richard K

    2016-02-01

    Vigorous systemic exercise stimulates a cascade of molecular and cellular processes that enhance central nervous system (CNS) plasticity and performance. The influence of heat stress on CNS performance and learning is novel. We designed two experiments to determine whether passive heat stress (1) facilitated motor cortex excitability and (2) improved motor task acquisition compared to no heat stress. Motor evoked potentials (MEPs) from the first dorsal interosseus (FDI) were collected before and after 30 min of heat stress at 73 °C. A second cohort of subjects performed a motor learning task using the FDI either following heat or the no heat condition. Heat stress increased heart rate to 65% of age-predicted maximum. After heat, mean resting MEP amplitude increased 48% (p<0.05). MEP stimulus-response amplitudes did not differ according to stimulus intensity. In the second experiment, heat stress caused a significant decrease in absolute and variable error (p<0.05) during a novel movement task using the FDI. Passive environmental heat stress (1) increases motor cortical excitability, and (2) enhances performance in a motor skill acquisition task. Controlled heat stress may prime the CNS to enhance motor skill acquisition during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  20. Effects of passive heating on central blood volume and ventricular dimensions in humans

    PubMed Central

    Crandall, C G; Wilson, T E; Marving, J; Vogelsang, T W; Kjaer, A; Hesse, B; Secher, N H

    2008-01-01

    Mixed findings regarding the effects of whole-body heat stress on central blood volume have been reported. This study evaluated the hypothesis that heat stress reduces central blood volume and alters blood volume distribution. Ten healthy experimental and seven healthy time control (i.e. non-heat stressed) subjects participated in this protocol. Changes in regional blood volume during heat stress and time control were estimated using technetium-99m labelled autologous red blood cells and gamma camera imaging. Whole-body heating increased internal temperature (≥ 1.0°C), cutaneous vascular conductance (approximately fivefold), and heart rate (52 ± 2 to 93 ± 4 beats min−1), while reducing central venous pressure (5.5 ± 07 to 0.2 ± 0.6 mmHg) accompanied by minor decreases in mean arterial pressure (all P < 0.05). The heat stress reduced the blood volume of the heart (18 ± 2%), heart plus central vasculature (17 ± 2%), thorax (14 ± 2%), inferior vena cava (23 ± 2%) and liver (23 ± 2%) (all P≤ 0.005 relative to time control subjects). Radionuclide multiple-gated acquisition assessment revealed that heat stress did not significantly change left ventricular end-diastolic volume, while ventricular end-systolic volume was reduced by 24 ± 6% of pre-heat stress levels (P < 0.001 relative to time control subjects). Thus, heat stress increased left ventricular ejection fraction from 60 ± 1% to 68 ± 2% (P= 0.02). We conclude that heat stress shifts blood volume from thoracic and splanchnic regions presumably to aid in heat dissipation, while simultaneously increasing heart rate and ejection fraction. PMID:17962331

  1. Simulation and optimization study of a solar seasonal storage district heating system: the Fox River Valley case study

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

    Michaels, A.I.; Sillman, S.; Baylin, F.

    1983-05-01

    A central solar-heating plant with seasonal heat storage in a deep underground aquifer is designed by means of a solar-seasonal-storage-system simulation code based on the Solar Energy Research Institute (SERI) code for Solar Annual Storage Simulation (SASS). This Solar Seasonal Storage Plant is designed to supply close to 100% of the annual heating and domestic-hot-water (DHW) load of a hypothetical new community, the Fox River Valley Project, for a location in Madison, Wisconsin. Some analyses are also carried out for Boston, Massachusetts and Copenhagen, Denmark, as an indication of weather and insolation effects. Analyses are conducted for five different typesmore » of solar collectors, and for an alternate system utilizing seasonal storage in a large water tank. Predicted seasonal performance and system and storage costs are calculated. To provide some validation of the SASS results, a simulation of the solar system with seasonal storage in a large water tank is also carried out with a modified version of the Swedish Solar Seasonal Storage Code MINSUN.« less

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

    M. Hoeschele, E. Weitzel

    Although heat pump water heaters (HPWHs) have gained significant attention in recent years as a high efficiency electric water heating solution for single family homes, central HPWHs for commercial or multi-family applications are not as well documented in terms of measured performance and cost effectiveness. To evaluate this technology, the Alliance for Residential Building Innovation team monitored the performance of a 10.5 ton central HPWH installed on a student apartment building at the West Village Zero Net Energy Community in Davis, California. Monitoring data collected over a 16-month period were then used to validate a TRNSYS simulation model. The TRNSYSmore » model was then used to project performance in different climates using local electric rates. Results of the study indicate that after some initial commissioning issues, the HPWH operated reliably with an annual average efficiency of 2.12 (Coefficient of Performance). The observed efficiency was lower than the unit's rated efficiency, primarily due to the fact that the system rarely operated under steady-state conditions. Changes in the system configuration, storage tank sizing, and control settings would likely improve the observed field efficiency. Modeling results suggest significant energy savings relative to electric storage water heating systems (typical annual efficiencies around 0.90) providing for typical simple paybacks of six to ten years without any incentives. The economics versus gas water heating are currently much more challenging given the current low natural gas prices in much of the country. Increased market size for this technology would benefit cost effectiveness and spur greater technology innovation.« less

  3. Recent trends in the development of heat exchangers for geothermal systems

    NASA Astrophysics Data System (ADS)

    Franco, A.; Vaccaro, M.

    2017-11-01

    The potential use of geothermal resources has been a remarkable driver for market players and companies operating in the field of geothermal energy conversion. For this reason, medium to low temperature geothermal resources have been the object of recent rise in consideration, with strong reference to the perspectives of development of Organic Rankine Cycle (ORC) technology. The main components of geothermal plants based on ORC cycle are surely the heat exchangers. A lot of different heat exchangers are required for the operation of ORC plants. Among those it is surely of major importance the Recovery Heat Exchanger (RHE, typically an evaporator), in which the operating fluid is evaporated. Also the Recuperator, in regenerative Organic Rankine Cycle, is of major interest in technology. Another important application of the heat exchangers is connected to the condensation, according to the possibility of liquid or air cooling media availability. The paper analyzes the importance of heat exchangers sizing and the connection with the operation of ORC power plants putting in evidence the real element of innovation: the consideration of the heat exchangers as central element for the optimum design of ORC systems.

  4. A Model for Determining Modular Heat Recovery Incinerator Feasibility on Air Force Installations.

    DTIC Science & Technology

    1992-09-01

    INCINERATOR FEASIBILITY ON AIR FORCE INSTALLATIONS THESIS Presented to the Faculty of the School of Engineering of the Air Force Institute of Technology...commer- cial, (and) institutional discards...not (including] industrial process or manufacturing discards, segre- gated medical waste, or construction...have "... particular 11 value as an additive to an existing steam system, such as a central heating plant for an institution " (46:E-26). Exam- ples

  5. Experimental performance investigation of a shell and tube heat exchanger by exergy based sensitivity analysis

    NASA Astrophysics Data System (ADS)

    Mert, Suha Orçun; Reis, Alper

    2016-06-01

    Heat exchangers are used extensively in many industrial branches, primarily so in chemical and energy sectors. They also have important household usage as they are used in central and local heating systems. Any betterment on heat exchangers will serve greatly in preserving our already dwindling and costly energy resources. Strong approach of exergy analysis -which helps find out where the first steps should be taken in determining sources of inefficiencies and how to remedy them- will be used as a means to this end. The maximum useful work that can be harnessed from systems relationships with its environment is defined as exergy. In this study, the inlet and outlet flow rate values of fluids and temperature of hot stream both on shell and tube parts of a shell-tube heat exchange system have been inspected and their effects on the exergy efficiency of this thermal system have been analyzed. It is seen that the combination of high tube side inlet temperature, low shell side flow rate and high tube side flow rate are found to be the optimum for this experimental system with reaching 75, 65, and 32 % efficiencies respectively. Selecting operating conditions suitable to this behavior will help to increase the overall efficiency of shell-tube heat exchange systems and cause an increment in energy conservation.

  6. 2010 Carl Ludwig Distinguished Lectureship of the APS Neural Control and Autonomic Regulation Section: Central neural pathways for thermoregulatory cold defense

    PubMed Central

    2011-01-01

    Central neural circuits orchestrate the homeostatic repertoire to maintain body temperature during environmental temperature challenges and to alter body temperature during the inflammatory response. This review summarizes the research leading to a model representing our current understanding of the neural pathways through which cutaneous thermal receptors alter thermoregulatory effectors: the cutaneous circulation for control of heat loss, and brown adipose tissue, skeletal muscle, and the heart for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific core efferent pathways within the central nervous system (CNS) that share a common peripheral thermal sensory input. The thermal afferent circuit from cutaneous thermal receptors includes neurons in the spinal dorsal horn projecting to lateral parabrachial nucleus neurons that project to the medial aspect of the preoptic area. Within the preoptic area, warm-sensitive, inhibitory output neurons control heat production by reducing the discharge of thermogenesis-promoting neurons in the dorsomedial hypothalamus. The rostral ventromedial medulla, including the raphe pallidus, receives projections form the dorsomedial hypothalamus and contains spinally projecting premotor neurons that provide the excitatory drive to spinal circuits controlling the activity of thermogenic effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a platform for further understanding of the functional organization of central thermoregulation. PMID:21270352

  7. Analysis and improvement of the cavity structure of steam receiver of 1MWe solar tower power plant

    NASA Astrophysics Data System (ADS)

    Yu, Qiang; Wang, Zhifeng; Zhu, Lingzhi

    2017-06-01

    The central receiver, which plays a dominant role in the radiation-heat conversion, is one of the most important components in the solar tower power plants. Its performance can directly affect the efficiency of the entire solar power generation system. In general, the performance of the central receiver is mainly determined by two aspects: the first is the receiver structure and arrangement of heating pipes, the other is the integral control and operation strategy. The former is the internal essence of the receiver and the latter is extrinsic. In this paper, the latter is temporarily not in the scope of the discussion. According to the previous cavity structure and arrangement of the heating pipes, it is found that there are varying degrees of deformation to the heating pipes, especially for the superheated pipes. In order to make some improvement for the cavity receiver, firstly, the most likely causes were analyzed according to the previous structure. Secondly, a possible cavity structure was proposed according to the calculation results. The results show that the performance of the receiver is better than the previous one.

  8. Evaluating Domestic Hot Water Distribution System Options With Validated Analysis Models

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

    Weitzel, E.; Hoeschele, M.

    2014-09-01

    A developing body of work is forming that collects data on domestic hot water consumption, water use behaviors, and energy efficiency of various distribution systems. A full distribution system developed in TRNSYS has been validated using field monitoring data and then exercised in a number of climates to understand climate impact on performance. This study builds upon previous analysis modelling work to evaluate differing distribution systems and the sensitivities of water heating energy and water use efficiency to variations of climate, load, distribution type, insulation and compact plumbing practices. Overall 124 different TRNSYS models were simulated. Of the configurations evaluated,more » distribution losses account for 13-29% of the total water heating energy use and water use efficiency ranges from 11-22%. The base case, an uninsulated trunk and branch system sees the most improvement in energy consumption by insulating and locating the water heater central to all fixtures. Demand recirculation systems are not projected to provide significant energy savings and in some cases increase energy consumption. Water use is most efficient with demand recirculation systems, followed by the insulated trunk and branch system with a central water heater. Compact plumbing practices and insulation have the most impact on energy consumption (2-6% for insulation and 3-4% per 10 gallons of enclosed volume reduced). The results of this work are useful in informing future development of water heating best practices guides as well as more accurate (and simulation time efficient) distribution models for annual whole house simulation programs.« less

  9. OVERVIEW OF CENTRAL HEATING PLANT, WITH OIL STORAGE ON LEFT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    OVERVIEW OF CENTRAL HEATING PLANT, WITH OIL STORAGE ON LEFT, BOILER BUILDING ON RIGHT, SOUTH AND EAST ELEVATIONS, CAMERA FACING NORTH. - New Haven Rail Yard, Central Steam Plant and Oil Storage, Vicinity of Union Avenue, New Haven, New Haven County, CT

  10. Building America Case Study: Boiler Control Replacement for Hydronically Heated Multifamily Buildings, Cambridge, Massachusetts (Fact Sheet)

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

    Not Available

    2014-11-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency. Efficient operation of themore » heating system faced several obstacles, including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68 degrees F) than day (73 degrees F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.« less

  11. Heat waves over Central Europe in regional climate model simulations

    NASA Astrophysics Data System (ADS)

    Lhotka, Ondřej; Kyselý, Jan

    2014-05-01

    Regional climate models (RCMs) have become a powerful tool for exploring impacts of global climate change on a regional scale. The aim of the study is to evaluate the capability of RCMs to reproduce characteristics of major heat waves over Central Europe in their simulations of the recent climate (1961-2000), with a focus on the most severe and longest Central European heat wave that occurred in 1994. We analyzed 7 RCM simulations with a high resolution (0.22°) from the ENSEMBLES project, driven by the ERA-40 reanalysis. In observed data (the E-OBS 9.0 dataset), heat waves were defined on the basis of deviations of daily maximum temperature (Tmax) from the 95% quantile of summer Tmax distribution in grid points over Central Europe. The same methodology was applied in the RCM simulations; we used corresponding 95% quantiles (calculated for each RCM and grid point) in order to remove the bias of modelled Tmax. While climatological characteristics of heat waves are reproduced reasonably well in the RCM ensemble, we found major deficiencies in simulating heat waves in individual years. For example, METNOHIRHAM simulated very severe heat waves in 1996, when no heat wave was observed. Focusing on the major 1994 heat wave, considerable differences in simulated temperature patterns were found among the RCMs. The differences in the temperature patterns were clearly linked to the simulated amount of precipitation during this event. The 1994 heat wave was almost absent in all RCMs that did not capture the observed precipitation deficit, while it was by far most pronounced in KNMI-RACMO that simulated virtually no precipitation over Central Europe during the 15-day period of the heat wave. By contrast to precipitation, values of evaporative fraction in the RCMs were not linked to severity of the simulated 1994 heat wave. This suggests a possible major contribution of other factors such as cloud cover and associated downward shortwave radiation. Therefore, a more detailed analysis of individual components of the energy budget over Central Europe during and before the 1994 heat wave was performed.

  12. Use of multilevel modeling for determining optimal parameters of heat supply systems

    NASA Astrophysics Data System (ADS)

    Stennikov, V. A.; Barakhtenko, E. A.; Sokolov, D. V.

    2017-07-01

    The problem of finding optimal parameters of a heat-supply system (HSS) is in ensuring the required throughput capacity of a heat network by determining pipeline diameters and characteristics and location of pumping stations. Effective methods for solving this problem, i.e., the method of stepwise optimization based on the concept of dynamic programming and the method of multicircuit optimization, were proposed in the context of the hydraulic circuit theory developed at Melentiev Energy Systems Institute (Siberian Branch, Russian Academy of Sciences). These methods enable us to determine optimal parameters of various types of piping systems due to flexible adaptability of the calculation procedure to intricate nonlinear mathematical models describing features of used equipment items and methods of their construction and operation. The new and most significant results achieved in developing methodological support and software for finding optimal parameters of complex heat supply systems are presented: a new procedure for solving the problem based on multilevel decomposition of a heat network model that makes it possible to proceed from the initial problem to a set of interrelated, less cumbersome subproblems with reduced dimensionality; a new algorithm implementing the method of multicircuit optimization and focused on the calculation of a hierarchical model of a heat supply system; the SOSNA software system for determining optimum parameters of intricate heat-supply systems and implementing the developed methodological foundation. The proposed procedure and algorithm enable us to solve engineering problems of finding the optimal parameters of multicircuit heat supply systems having large (real) dimensionality, and are applied in solving urgent problems related to the optimal development and reconstruction of these systems. The developed methodological foundation and software can be used for designing heat supply systems in the Central and the Admiralty regions in St. Petersburg, the city of Bratsk, and the Magistral'nyi settlement.

  13. Badgastein spa—Austrian central Alps

    NASA Astrophysics Data System (ADS)

    Zötl, J. G.

    1995-12-01

    The Badgastein spa shows almost all the special geological and hydrological features existing in the northeastern central Alps. Situated within the Tauern window, the open joint system enables the infiltration of surface water to great depths. There it becomes heated and loaded with radon and trace elements such as fluor. The water discharges as thermal water springs at the steep right flank of the cascade of the Gastein-Ache. This hydraulic process occurs during a span of 3600 3800 years. The springs are captured in galleries, and the largest discharge is in gallery IX (2518 m3/d-1). The spa became known worldwide in the 19th century by visiting aristocrats from Central and Eastern Europe. The most important event in the 20th century was the discovery of the heat joint in the Böckstein gallery. In 1940 an effort to reactivate gold mining in the Radhausberg near Böckstein south of Badgastein failed. However, the miners had the unexpected experience of being cured of rheumatism. A connection between the great depth and high temperature in the gallery was made by the discovery of the joint set with heat and radon emanation. In the medical stations of the Böckstein gallery treatment of polyarthritis has become especially successful.

  14. Relevance of air conditioning for 222Radon concentration in shops of the Savona Province, Italy.

    PubMed

    Panatto, Donatella; Ferrari, Paola; Lai, Piero; Gallelli, Giovanni

    2006-02-15

    Radon (222Rn) concentration was evaluated in shops of the Savona Province, Italy, between summer 2002 and winter 2002-2003. The main characteristics of each shops were recorded through a questionnaire investigating the ventilation rate and factors related to 222Rn precursors in the soil and the construction materials. The main variables that were related to radon concentration were the following: age of the building, level of the shop above ground, season of the year, wind exposure, active windows, and type of heating system. Shops equipped with individual air heating/conditioning systems exhibited radon concentrations that were three times higher than those of shops heated by centralized furnaces. Our data indicate that the level of pollution in the shops was of medium level, with an expected low impact on the salespersons' health. Only in wintertime, the action level of 200 Bq m(-3) for the confined environment was reached in 10 shops equipped with individual air heating/conditioning systems.

  15. Crustal heat production and estimate of terrestrial heat flow in central East Antarctica, with implications for thermal input to the East Antarctic ice sheet

    NASA Astrophysics Data System (ADS)

    Goodge, John W.

    2018-02-01

    Terrestrial heat flow is a critical first-order factor governing the thermal condition and, therefore, mechanical stability of Antarctic ice sheets, yet heat flow across Antarctica is poorly known. Previous estimates of terrestrial heat flow in East Antarctica come from inversion of seismic and magnetic geophysical data, by modeling temperature profiles in ice boreholes, and by calculation from heat production values reported for exposed bedrock. Although accurate estimates of surface heat flow are important as an input parameter for ice-sheet growth and stability models, there are no direct measurements of terrestrial heat flow in East Antarctica coupled to either subglacial sediment or bedrock. As has been done with bedrock exposed along coastal margins and in rare inland outcrops, valuable estimates of heat flow in central East Antarctica can be extrapolated from heat production determined by the geochemical composition of glacial rock clasts eroded from the continental interior. In this study, U, Th, and K concentrations in a suite of Proterozoic (1.2-2.0 Ga) granitoids sourced within the Byrd and Nimrod glacial drainages of central East Antarctica indicate average upper crustal heat production (Ho) of about 2.6 ± 1.9 µW m-3. Assuming typical mantle and lower crustal heat flux for stable continental shields, and a length scale for the distribution of heat production in the upper crust, the heat production values determined for individual samples yield estimates of surface heat flow (qo) ranging from 33 to 84 mW m-2 and an average of 48.0 ± 13.6 mW m-2. Estimates of heat production obtained for this suite of glacially sourced granitoids therefore indicate that the interior of the East Antarctic ice sheet is underlain in part by Proterozoic continental lithosphere with an average surface heat flow, providing constraints on both geodynamic history and ice-sheet stability. The ages and geothermal characteristics of the granites indicate that crust in central East Antarctica resembles that in the Proterozoic Arunta and Tennant Creek inliers of Australia but is dissimilar to other areas like the Central Australian Heat Flow Province that are characterized by anomalously high heat flow. Age variation within the sample suite indicates that central East Antarctic lithosphere is heterogeneous, yet the average heat production and heat flow of four age subgroups cluster around the group mean, indicating minor variation in the thermal contribution to the overlying ice sheet from upper crustal heat production. Despite these minor differences, ice-sheet models may favor a geologically realistic input of crustal heat flow represented by the distribution of ages and geothermal characteristics found in these glacial clasts.

  16. Nanotube Heterojunctions and Endo-Fullerenes for Nanoelectronics

    NASA Technical Reports Server (NTRS)

    Srivastava, Deepak; Menon, M.; Andriotis, Antonis; Cho, K.; Park, Jun; Biegel, Bryan A. (Technical Monitor)

    2002-01-01

    Topics discussed include: (1) Light-Weight Multi-Functional Materials: Nanomechanics; Nanotubes and Composites; Thermal/Chemical/Electrical Characterization; (2) Biomimetic/Revolutionary Concepts: Evolutionary Computing and Sensing; Self-Heating Materials; (3) Central Computing System: Molecular Electronics; Materials for Quantum Bits; and (4) Molecular Machines.

  17. Energy Use Consequences of Ventilating a Net-Zero Energy House

    PubMed Central

    Ng, Lisa C.; Payne, W. Vance

    2016-01-01

    A Net-Zero Energy Residential Test Facility (NZERTF) has been constructed at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland to demonstrate that a home similar in size, aesthetics, and amenities to those in the surrounding communities can achieve net-zero energy use over the course of a year while meeting the average electricity and water use needs of a family of four in the United States. The facility incorporates renewable energy and energy efficient technologies, including an air-to-air heat pump system, a solar photovoltaic system, a solar thermal domestic hot water system, and a heat recovery ventilation system sized to meet American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) Standard 62.2-2010 ventilation requirements. The largest energy end use within the home was space conditioning, which included heat loss through the building envelope, ventilation air supplied by the heat recovery ventilator (HRV), and internal loads. While HRVs are often described as being able to save energy when compared to ventilating without heat recovery, there have been no studies using a full year of measured data that determine the thermal load and energy impacts of HRV-based ventilation on the central heating and cooling system. Over the course of a year, continuous operation of the HRV at the NZERTF resulted in an annual savings of 7 % in heat pump energy use compared with the hypothetical case of ventilating without heat recovery. The heat pump electrical use varied from an increase of 5 % in the cooling months to 36 % savings in the heating months compared with ventilation without heat recovery. The increase in the cooling months occurred when the outdoor temperature was lower than the indoor temperature, during which the availability of an economizer mode would have been beneficial. Nevertheless, the fan energy required to operate the selected HRV at the NZERTF paid for itself in the heat pump energy saved compared with ventilation without heat recovery. PMID:26903776

  18. Energy Use Consequences of Ventilating a Net-Zero Energy House.

    PubMed

    Ng, Lisa C; Payne, W Vance

    2016-03-05

    A Net-Zero Energy Residential Test Facility (NZERTF) has been constructed at the National Institute of Standards and Technology (NIST) in Gaithersburg, Maryland to demonstrate that a home similar in size, aesthetics, and amenities to those in the surrounding communities can achieve net-zero energy use over the course of a year while meeting the average electricity and water use needs of a family of four in the United States. The facility incorporates renewable energy and energy efficient technologies, including an air-to-air heat pump system, a solar photovoltaic system, a solar thermal domestic hot water system, and a heat recovery ventilation system sized to meet American Society of Heating, Refrigeration, and Air-Conditioning Engineers (ASHRAE) Standard 62.2-2010 ventilation requirements. The largest energy end use within the home was space conditioning, which included heat loss through the building envelope, ventilation air supplied by the heat recovery ventilator (HRV), and internal loads. While HRVs are often described as being able to save energy when compared to ventilating without heat recovery, there have been no studies using a full year of measured data that determine the thermal load and energy impacts of HRV-based ventilation on the central heating and cooling system. Over the course of a year, continuous operation of the HRV at the NZERTF resulted in an annual savings of 7 % in heat pump energy use compared with the hypothetical case of ventilating without heat recovery. The heat pump electrical use varied from an increase of 5 % in the cooling months to 36 % savings in the heating months compared with ventilation without heat recovery. The increase in the cooling months occurred when the outdoor temperature was lower than the indoor temperature, during which the availability of an economizer mode would have been beneficial. Nevertheless, the fan energy required to operate the selected HRV at the NZERTF paid for itself in the heat pump energy saved compared with ventilation without heat recovery.

  19. The study and development of the empirical correlations equation of natural convection heat transfer on vertical rectangular sub-channels

    NASA Astrophysics Data System (ADS)

    Kamajaya, Ketut; Umar, Efrizon; Sudjatmi, K. S.

    2012-06-01

    This study focused on natural convection heat transfer using a vertical rectangular sub-channel and water as the coolant fluid. To conduct this study has been made pipe heaters are equipped with thermocouples. Each heater is equipped with five thermocouples along the heating pipes. The diameter of each heater is 2.54 cm and 45 cm in length. The distance between the central heating and the pitch is 29.5 cm. Test equipment is equipped with a primary cooling system, a secondary cooling system and a heat exchanger. The purpose of this study is to obtain new empirical correlations equations of the vertical rectangular sub-channel, especially for the natural convection heat transfer within a bundle of vertical cylinders rectangular arrangement sub-channels. The empirical correlation equation can support the thermo-hydraulic analysis of research nuclear reactors that utilize cylindrical fuel rods, and also can be used in designing of baffle-free vertical shell and tube heat exchangers. The results of this study that the empirical correlation equations of natural convection heat transfer coefficients with rectangular arrangement is Nu = 6.3357 (Ra.Dh/x)0.0740.

  20. Light bulb heat exchanger for magnetohydrodynamic generator applications - Preliminary evaluation

    NASA Technical Reports Server (NTRS)

    Smith, J. M.; Hwang, C. C.; Seikel, G. R.

    1974-01-01

    The light-bulb heat-exchanger concept is investigated as a possible means of using a combustion heat source to supply energy to an inert gas MHD power generator system. In this concept, combustion gases flow through a central passage which consists of a duct with transparent walls through which heat is transferred by radiation to a radiation receiver which in turn heats the inert gas by convection. The effects of combustion-gas emissivity, transparent-wall-transmissivity, radiation-receiver emissivity, and the use of fins in the inert gas coolant passage are studied. The results indicate that inert gas outlet temperatures of 2500 K are possible for combustion temperatures of 3200 K and that sufficient energy can be transferred from the combustion gas to reduce its temperature to approximately 2000 K. At this temperature more conventional heat exchangers can be used.

  1. Mass-action model analysis of the apparent molar volume and heat capacity of pluronics in water and liposome suspensions at 25 °C.

    PubMed

    Quirion, François; Meilleur, Luc; Lévesque, Isabelle

    2013-07-09

    Pluronics are block copolymers composed of a central block of polypropylene oxide and two side chains of polyethylene oxide. They are used in water to generate aggregates and gels or added to phospholipid suspensions to prepare microparticles for drug delivery applications. The structure of these systems has been widely investigated. However, little is known about the mechanisms leading to these structures. This investigation compares the apparent molar volumes and heat capacities of Pluronics F38, F108, F127, P85, P104, and P103 at 25 °C in water and in the presence of lecithin liposomes. The changes in molar volumes, heat capacities, and enthalpies generated by a mass-action model are in good agreement with the loss of hydrophobic hydration of the polypropylene oxide central block of the Pluronics. However, the molecularity of the endothermic transitions is much smaller than the aggregation numbers reported in the literature for the same systems. It is suggested that Pluronics go through dehydration of their central block to form unimolecular or small entities having a hydrophobic polypropylene oxide core. In water, these entities would assemble athermally to form larger aggregates. In the presence of liposomes, they would be transferred into the hydrophobic lecithin bilayers of the liposomes. Light transmission experiments suggest that the liposome suspensions are significantly altered only when the added Pluronics are in the dehydrated state.

  2. Central mediators involved in the febrile response: effects of antipyretic drugs

    PubMed Central

    Zampronio, Aleksander R; Soares, Denis M; Souza, Glória E P

    2015-01-01

    Fever is a complex signal of inflammatory and infectious diseases. It is generally initiated when peripherally produced endogenous pyrogens reach areas that surround the hypothalamus. These peripheral endogenous pyrogens are cytokines that are produced by leukocytes and other cells, the most known of which are interleukin-1β, tumor necrosis factor-α, and interleukin-6. Because of the capacity of these molecules to induce their own synthesis and the synthesis of other cytokines, they can also be synthesized in the central nervous system. However, these pyrogens are not the final mediators of the febrile response. These cytokines can induce the synthesis of cyclooxygenase-2, which produces prostaglandins. These prostanoids alter hypothalamic temperature control, leading to an increase in heat production, the conservation of heat, and ultimately fever. The effect of antipyretics is based on blocking prostaglandin synthesis. In this review, we discuss recent data on the importance of prostaglandins in the febrile response, and we show that some endogenous mediators can still induce the febrile response even when known antipyretics reduce the levels of prostaglandins in the central nervous system. These studies suggest that centrally produced mediators other than prostaglandins participate in the genesis of fever. Among the most studied central mediators of fever are corticotropin-releasing factor, endothelins, chemokines, endogenous opioids, and substance P, which are discussed herein. Additionally, recent evidence suggests that these different pathways of fever induction may be activated during different pathological conditions. PMID:27227071

  3. Technology Solutions Case Study: Boiler Control Replacement for Hydronically Heated Multifamily Buildings, Cambridge, Massachusetts

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

    None

    2014-11-01

    The ARIES Collaborative, a U.S. Department of Energy Building America research team, partnered with NeighborWorks America affiliate Homeowners' Rehab Inc. (HRI) of Cambridge, Massachusetts, to study improvements to the central hydronic heating system in one of the nonprofit's housing developments. The heating controls in the three-building, 42-unit Columbia Cambridge Alliance for Spanish Tenants housing development were upgraded. Fuel use in the development was excessive compared to similar properties. A poorly insulated thermal envelope contributed to high energy bills, but adding wall insulation was not cost-effective or practical. The more cost-effective option was improving heating system efficiency, which faced several obstacles,more » including inflexible boiler controls and failed thermostatic radiator valves. Boiler controls were replaced with systems that offer temperature setbacks and one that controls heat based on apartment temperature in addition to outdoor temperature. Utility bill analysis shows that post-retrofit weather-normalized heating energy use was reduced by 10%-31% (average of 19%). Indoor temperature cutoff reduced boiler runtime (and therefore heating fuel consumption) by 28% in the one building in which it was implemented. Nearly all savings were obtained during night which had a lower indoor temperature cut off (68°F) than day (73° F). This implies that the outdoor reset curve was appropriately adjusted for this building for daytime operation. Nighttime setback of heating system supply water temperature had no discernable impact on boiler runtime or gas bills.« less

  4. Heat perturbation spreading in the Fermi-Pasta-Ulam-β system with next-nearest-neighbor coupling: Competition between phonon dispersion and nonlinearity

    NASA Astrophysics Data System (ADS)

    Xiong, Daxing

    2017-06-01

    We employ the heat perturbation correlation function to study thermal transport in the one-dimensional Fermi-Pasta-Ulam-β lattice with both nearest-neighbor and next-nearest-neighbor couplings. We find that such a system bears a peculiar phonon dispersion relation, and thus there exists a competition between phonon dispersion and nonlinearity that can strongly affect the heat correlation function's shape and scaling property. Specifically, for small and large anharmoncities, the scaling laws are ballistic and superdiffusive types, respectively, which are in good agreement with the recent theoretical predictions; whereas in the intermediate range of the nonlinearity, we observe an unusual multiscaling property characterized by a nonmonotonic delocalization process of the central peak of the heat correlation function. To understand these multiscaling laws, we also examine the momentum perturbation correlation function and find a transition process with the same turning point of the anharmonicity as that shown in the heat correlation function. This suggests coupling between the momentum transport and the heat transport, in agreement with the theoretical arguments of mode cascade theory.

  5. Cerebrovascular dysfunction is an attractive target for therapy in heat stroke.

    PubMed

    Chen, Sheng-Hsien; Niu, Ko-Chi; Lin, Mao-Tsun

    2006-08-01

    1. The aim of the present review is to summarize clinical observations and results of animal models that advance the knowledge of the attenuation of cerebrovascular dysfunction in the setting of heat stroke. It is a narrative review of selected published literature from Medline over the period 1959-2005. 2. All heat-stressed rodents, even under general anaesthesia, have hyperthermia, systemic inflammation, hypercoagulable state, arterial hypotension and tissue ischaemia and injury in multiple organs. These findings demonstrate that rodent heat stroke models can nearly mirror the full spectrum of human heat stroke. Experimental heat stroke fulfills the empirical triad used for the diagnosis of classical human heat stroke, namely hyperthermia, central nervous system alterations and a history of heat stress. 3. These physiological dysfunctions and survival during heat stroke can be improved by whole-body or brain cooling therapy adopted immediately after the onset of heat stroke. 4. However, in the absence of body or brain cooling, these heat stroke reactions can still be reduced by the following measures: (i) fluid replacement with 3% NaCl solution, 10% human albumin or hydroxyethyl starch; (ii) intravenous delivery of anti-inflammatory drugs, free radical scavengers or interleukin-1 receptor antagonists; (iii) hyperbaric oxygen therapy; or (iv) transplantation of human umbilical cord blood cells. 5. In addition, before initiation of heat stress, prior manipulations with one of the following measures was found to be able to protect against heat stroke reactions: (i) systemic delivery of alpha-tocopherol, mannitol, inducible nitric oxide synthase inhibitors, mu-opioid receptor antagonists, endothelin ETA receptor antagonists, serotoninergic nerve depletors or receptor antagonists, or glutamate receptor antagonists; or (ii) heat shock protein 72 preconditioning. 6. There is compelling evidence that cerebrovascular dysfunction is an attractive target for therapy in heat stroke.

  6. Function and regulation of heat shock factor 2 during mouse embryogenesis

    PubMed Central

    Rallu, M.; Loones, Mt.; Lallemand, Y.; Morimoto, R.; Morange, M.; Mezger, V.

    1997-01-01

    The spontaneous expression of heat shock genes during development is well documented in many animal species, but the mechanisms responsible for this developmental regulation are only poorly understood. In vertebrates, additional heat shock transcription factors, distinct from the heat shock factor 1 (HSF1) involved in the stress response, were suggested to be involved in this developmental control. In particular, the mouse HSF2 has been found to be active in testis and during preimplantation development. However, the role of HSF2 and its mechanism of activation have remained elusive due to the paucity of data on its expression during development. In this study, we have examined HSF2 expression during the postimplantation phase of mouse development. Our data show a developmental regulation of HSF2, which is expressed at least until 15.5 days of embryogenesis. It becomes restricted to the central nervous system during the second half of gestation. It is expressed in the ventricular layer of the neural tube which contains mitotically active cells but not in postmitotic neurons. Parallel results were obtained for mRNA, protein, and activity levels, demonstrating that the main level of control was transcriptional. The detailed analysis of the activity of a luciferase reporter gene under the control of the hsp70.1 promoter, as well as the description of the protein expression patterns of the major heat shock proteins in the central nervous system, show that HSF2 and heat shock protein expression domains do not coincide. This result suggests that HFS2 might be involved in other regulatory developmental pathways and paves the way to new functional approaches. PMID:9122205

  7. Analysis of Thermal and Reaction Times for Hydrogen Reduction of Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Hegde, U.; Balasubramaniam, R.; Gokoglu, S.

    2008-01-01

    System analysis of oxygen production by hydrogen reduction of lunar regolith has shown the importance of the relative time scales for regolith heating and chemical reaction to overall performance. These values determine the sizing and power requirements of the system and also impact the number and operational phasing of reaction chambers. In this paper, a Nusselt number correlation analysis is performed to determine the heat transfer rates and regolith heat up times in a fluidized bed reactor heated by a central heating element (e.g., a resistively heated rod, or a solar concentrator heat pipe). A coupled chemical and transport model has also been developed for the chemical reduction of regolith by a continuous flow of hydrogen. The regolith conversion occurs on the surfaces of and within the regolith particles. Several important quantities are identified as a result of the above analyses. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the particle Reynolds number, the Archimedes number, and the time needed for hydrogen to diffuse into the pores of the regolith particles. The analysis is used to determine the heat up and reaction times and its application to NASA s oxygen production system modeling tool is noted.

  8. Analysis of Thermal and Reaction Times for Hydrogen Reduction of Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Hegde, U.; Balasubramaniam, R.; Gokoglu, S.

    2009-01-01

    System analysis of oxygen production by hydrogen reduction of lunar regolith has shown the importance of the relative time scales for regolith heating and chemical reaction to overall performance. These values determine the sizing and power requirements of the system and also impact the number and operational phasing of reaction chambers. In this paper, a Nusselt number correlation analysis is performed to determine the heat transfer rates and regolith heat up times in a fluidized bed reactor heated by a central heating element (e.g., a resistively heated rod, or a solar concentrator heat pipe). A coupled chemical and transport model has also been developed for the chemical reduction of regolith by a continuous flow of hydrogen. The regolith conversion occurs on the surfaces of and within the regolith particles. Several important quantities are identified as a result of the above analyses. Reactor scale parameters include the void fraction (i.e., the fraction of the reactor volume not occupied by the regolith particles) and the residence time of hydrogen in the reactor. Particle scale quantities include the particle Reynolds number, the Archimedes number, and the time needed for hydrogen to diffuse into the pores of the regolith particles. The analysis is used to determine the heat up and reaction times and its application to NASA s oxygen production system modeling tool is noted.

  9. The Characteristics of Heat Flow in the Ryukyu Trench-Arc-Basin System: Constraints on Thermal Structure and Evolution of the Okinawa Trough

    NASA Astrophysics Data System (ADS)

    Zhang, L.

    2017-12-01

    Heat flow is an important constraint to study the thermal structure and evolution in modeling experiments. Based on the surface heat flow map and recent geochemistry results, a 2D transient heat conduction-advection model is used to investigate how the effects of sedimentation rate, magmatic intrusion, extension duration and rate on the surface heat flow distribution of the Okinawa Trough. Surface heat flow distribution map is interpolated based on a data set with 664 measurements in the Ryukyu trench-arc-basin system. The map shows an obviously correspondence between heat flows and tectonic zones, characterized by belts in E-W and blocks in S-N. The heat flow is extremely high and variable in the central Okinawa Trough (COT). The lowest heat values are distributed in the northwest of West Philippine Sea near the Ryukyu Trench. This phenomenon is likely related to increasing hydrothermal circulation of cold water into the upper portion of the incoming plate because of bend-faulting and little sediment coverage. Simulation results show that (1) High sedimentation rate can reduce heat flow by 30-35 % in the southern OT. (2) The sedimentation-corrected heat flow indicates that mantle upwelling occurred in the whole OT. The isotherm of 1000°C reaches to the depth of 19 km in the axil of the COT after 10 Ma. (3) The heat flow can be improved drastically by dyke intrusion along normal faults, but subsequent decreases rapidly about 15% after 0.1 Ma, which indicates the age of dyke intrusion under the Iheya area is younger than 0.5 Ma, and the depth is shallower than 2 km. Moreover, the magma fluid upward migrated along the magma conduits is required for the extremely high heat flow and its Darcy velocity can reach to 9 cm/yr. Based on the distribution of heat flow, we suggest that there is a different evolution model between the central- northern OT and the southern. The time of rifting in the NOT-COT began at 10 Ma with the mean rate of 0.4 cm/yr, while the rifting of the SOT started from 6 Ma with higher rate of 0.6 cm/yr.

  10. Increasing the efficiency of the condensing boiler

    NASA Astrophysics Data System (ADS)

    Zaytsev, O. N.; Lapina, E. A.

    2017-11-01

    Analysis of existing designs of boilers with low power consumption showed that the low efficiency of the latter is due to the fact that they work in most cases when the heating period in the power range is significantly less than the nominal power. At the same time, condensing boilers do not work in the most optimal mode (in condensing mode) in the central part of Russia, a significant part of their total operating time during the heating season. This is due to existing methods of equipment selection and joint operation with heating systems with quantitative control of the coolant. It was also revealed that for the efficient operation of the heating system, it is necessary to reduce the inertia of the heat generating equipment. Theoretical patterns of thermal processes in the furnace during combustion gas at different radiating surfaces location schemes considering the influence of the very furnace configuration, characterized in that to reduce the work condensing boiler in conventional gas boiler operation is necessary to maintain a higher temperature in the furnace (in the part where spiral heat exchangers are disposed), which is possible when redistributing heat flow - increase the proportion of radiant heat from the secondary burner emitter allow Perey For the operation of the condensing boiler in the design (condensation) mode practically the entire heating period.

  11. Cryogenic Considerations for Superconducting Magnet Design for the Material Plasma Exposure eXperiment

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

    Duckworth, Robert C; Demko, Dr. Jonathan A; Lumsdaine, Arnold

    2015-01-01

    In order to determine long term performance of plasma facing components such as diverters and first walls for fusion devices, next generation plasma generators are needed. A Material Plasma Exposure eXperiment (MPEX) has been proposed to address this need through the generation of plasmas in front of the target with electron temperatures of 1-15 eV and electron densities of 1020 to 1021 m-3. Heat fluxes on target diverters could reach 20 MW/m2. In order generate this plasma, a unique radio frequency helicon source and heating of electrons and ions through Electron Bernstein Wave (EBW) and Ion Cyclotron Resonance Heating (ICRH)more » has been proposed. MPEX requires a series of magnets with non-uniform central fields up to 2 T over a 5m length in the heating and transport region and 1 T uniform central field over a 1-m length on a diameter of 1.3 m. Given the field requirements, superconducting magnets are under consideration for MPEX. In order to determine the best construction method for the magnets, the cryogenic refrigeration has been analyzed with respect to cooldown and operational performance criteria for open-cycle and closed-cycle systems, capital and operating costs of these system, and maturity of supporting technology such as cryocoolers. These systems will be compared within the context of commercially available magnet constructions to determine the most economical method for MPEX operation. The current state of the MPEX magnet design including details on possible superconducting magnet configurations will be presented.« less

  12. Development, implementation, and validation of a modeling system for the San Francisco Bay and Estuary

    NASA Astrophysics Data System (ADS)

    Chao, Yi; Farrara, John D.; Zhang, Hongchun; Zhang, Yinglong J.; Ateljevich, Eli; Chai, Fei; Davis, Curtiss O.; Dugdale, Richard; Wilkerson, Frances

    2017-07-01

    A three-dimensional numerical modeling system for the San Francisco Bay is presented. The system is based on an unstructured grid numerical model known as Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM). The lateral boundary condition is provided by a regional coastal ocean model. The surface forcing is provided by a regional atmospheric model. The SCHISM results from a decadal hindcast run are compared with available tide gauge data, as well as a collection of temperature and salinity profiles. An examination of the observed climatological annual mean salinities at the United States Geological Survey (USGS) stations shows the highest salinities to be in the open ocean and the lowest well north (upstream) of the Central Bay, a pattern that does not change substantially with season. The corresponding mean SCHISM salinities reproduced the observed variations with location quite well, though with a fresh bias. The lowest values within the Bay occur during spring and the highest values during autumn, mirroring the seasonal variations in river discharge. The corresponding observed mean temperatures within the Bay were 2 to 3° C cooler in the Central Bay than to either the north or south. This observed pattern of a cooler Central Bay was not particularly well reproduced in the SCHISM results, which also showed a cold bias. Examination of the seasonal means revealed that the cool Central Bay pattern is found only during summer in the SCHISM results. The persistent cold and fresh biases in the model control run were nearly eliminated in a sensitivity run with modifications to the surface heat flux and river discharge. The surface atmospheric forcing and the heat flux at the western boundary are found to be the two major terms in a SCHISM-based heat budget analysis of the mean seasonal temperature cycle for the Central Bay. In the Central Bay salt budget, freshwater discharged by rivers into upstream portions of the Bay to the north balanced by the influx of salt from the west are the primary drivers of the mean seasonal salinity cycle. Concerning the interannual variability in temperatures, the warm anomalies during the period 2014-16 were the strongest and most persistent departures from normal during the period analyzed and were realistically reproduced by SCHISM. The most prominent salinity anomalies in both the observations and SCHISM results were the salty anomalies that persisted for most of the four-year California drought of 2012-2015.

  13. 76 FR 18105 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Central Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-01

    ... the low-voltage transformer used when testing coil-only residential central air conditioners and heat... the Low-Voltage Transformer Used When Testing Coil- Only Central Air Conditioners and Heat Pumps and... metric, estimating off-mode energy consumption, and selecting the low- voltage transformer in the test...

  14. Regional energy planning: Some suggestions to public administration

    NASA Astrophysics Data System (ADS)

    Sozzi, R.

    A methodology is proposed to estimate the relevant data and to improve the energy efficiency in regional energy planning. The quantification of the regional energy system is subdivided in three independent parameters which are separetely estimated: energy demand, energy consumption, and transformation capacity. Definitions and estimating procedures are given. The optimization of the regional planning includes the application, wherever possible, of the technologies which centralize the space-heating energy production or combine the production of electric energy with space-heating energy distribution.

  15. 7 CFR 1924.253 - Definitions.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) Serious defects in or improper installation of heating systems or central air conditioning. (4) Defects in... CONSTRUCTION AND REPAIR Complaints and Compensation for Construction Defects § 1924.253 Definitions. As used in..., smoke detectors, railings, etc., as well as failure to provide or properly install devices to aid...

  16. 7 CFR 1924.253 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) Serious defects in or improper installation of heating systems or central air conditioning. (4) Defects in... CONSTRUCTION AND REPAIR Complaints and Compensation for Construction Defects § 1924.253 Definitions. As used in..., smoke detectors, railings, etc., as well as failure to provide or properly install devices to aid...

  17. 7 CFR 1924.253 - Definitions.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) Serious defects in or improper installation of heating systems or central air conditioning. (4) Defects in... CONSTRUCTION AND REPAIR Complaints and Compensation for Construction Defects § 1924.253 Definitions. As used in..., smoke detectors, railings, etc., as well as failure to provide or properly install devices to aid...

  18. 7 CFR 1924.253 - Definitions.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) Serious defects in or improper installation of heating systems or central air conditioning. (4) Defects in... CONSTRUCTION AND REPAIR Complaints and Compensation for Construction Defects § 1924.253 Definitions. As used in..., smoke detectors, railings, etc., as well as failure to provide or properly install devices to aid...

  19. A Systematic Classification for HVAC Systems and Components

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

    Li, Han; Chen, Yan; Zhang, Jian

    Depending on the application, the complexity of an HVAC system can range from a small fan coil unit to a large centralized air conditioning system with primary and secondary distribution loops, and central plant components. Currently, the taxonomy of HVAC systems and the components has various aspects, which can get quite complex because of the various components and system configurations. For example, based on cooling and heating medium delivered to terminal units, systems can be classified as either air systems, water systems or air-water systems. In addition, some of the system names might be commonly used in a confusing manner,more » such as “unitary system” vs. “packaged system.” Without a systematic classification, these components and system terminology can be confusing to understand or differentiate from each other, and it creates ambiguity in communication, interpretation, and documentation. It is valuable to organize and classify HVAC systems and components so that they can be easily understood and used in a consistent manner. This paper aims to develop a systematic classification of HVAC systems and components. First, we summarize the HVAC component information and definitions based on published literature, such as ASHRAE handbooks, regulations, and rating standards. Then, we identify common HVAC system types and map them to the collected components in a meaningful way. Classification charts are generated and described based on the component information. Six main categories are identified for the HVAC components and equipment, i.e., heating and cooling production, heat extraction and rejection, air handling process, distribution system, terminal use, and stand-alone system. Components for each main category are further analyzed and classified in detail. More than fifty system names are identified and grouped based on their characteristics. The result from this paper will be helpful for education, communication, and systems and component documentation.« less

  20. Systematic heat flow measurements across the Wagner Basin, northern Gulf of California

    NASA Astrophysics Data System (ADS)

    Neumann, Florian; Negrete-Aranda, Raquel; Harris, Robert N.; Contreras, Juan; Sclater, John G.; González-Fernández, Antonio

    2017-12-01

    A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. The heat flow profile is 40 km long, has a nominal measurement spacing of ∼1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Although heat flow data were collected in shallow water, where there are significant temporal variations in bottom water temperature, we use CTD data collected over many years to correct our measurements to yield accurate values of heat flow. After correction for bottom water temperature, the mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220 ± 60, 99 ± 14, 889 ± 419 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Moreover, heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

  1. A Systematic Method for the Condition Assessment of Central Heating Plants in Air Force Logistics Command

    DTIC Science & Technology

    1990-09-01

    Oil Combustion/Fuel System 59 Derivation of HTHW Plant Condition Indices ...... ................. .. 65 Distribution System . ........ .. 66 HTHW...with Load ..... ............... .. 54 3. Boiler Efficiency Curve for Gas Combustion . 61 4. Boiler Efficiency Curve for Oil Combustion . 62 v List of...147 6. Round One Relative Responses for Gas and Oil Combustion/Fue System .... ............ . 147 7. Round One Relative Responses for Coal - Combustion

  2. Final Report: Cooling Seasonal Energy and Peak Demand Impacts of Improved Duct Insulation on Fixed-Capacity (SEER 13) and Variable-Capacity (SEER 22) Heat Pumps

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

    Withers, C.; Cummings, J.; Nigusse, B.

    A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied bymore » adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.« less

  3. Friction pull plug welding: chamfered heat sink pull plug design

    NASA Technical Reports Server (NTRS)

    Coletta, Edmond R. (Inventor); Cantrell, Mark A. (Inventor)

    2002-01-01

    Friction Pull Plug Welding (FPPW) is a solid state repair process for defects up to one inch in length, only requiring single sided tooling (OSL) for usage on flight hardware. Experimental data has shown that the mass of plug heat sink remaining above the top of the plate surface after a weld is completed (the plug heat sink) affects the bonding at the plug top. A minimized heat sink ensures complete bonding of the plug to the plate at the plug top. However, with a minimal heat sink three major problems can arise, the entire plug could be pulled through the plate hole, the central portion of the plug could be separated along grain boundaries, or the plug top hat can be separated from the body. The Chamfered Heat Sink Pull Plug Design allows for complete bonding along the ISL interface through an outside diameter minimal mass heat sink, while maintaining enough central mass in the plug to prevent plug pull through, central separation, and plug top hat separation.

  4. Large scale atmospheric drivers for heat waves in the Mediterranean Basin

    NASA Astrophysics Data System (ADS)

    Pasqui, Massimiliano; Di Giuseppe, Edmondo

    2016-04-01

    West African Heat Low (WAHL) is one of the prominent dynamical components of the West African Monsoon (WAM) system playing a key role in the summer atmospheric circulation over Mediterranean as well. It is characterized by a semi-permanent low pressure system generated and maintained by surface heating over the western part of Saharan desert in summer, and a divergent flux pattern above the atmospheric boundary level. In this study we analyse the formation and occurrence of heat waves in the Mediterranean Basin connected to the WAHL regimes in combination with the subtropical anticyclone regimes over North Atlantic basin (the "Azore High") . In this work, heat waves are defined when more than 6 consecutive days with a daily temperature above 90th percentile corresponding threshold are observed. We use 1971-2000 as reference period for thresholds calculation, based on two datasets: a) the European Climate Assessment & Dataset (ECAD/E-OBS) data; b) the Berkeley-Earth Project data; the analysis period covers March-September from 1951 to 2015 and 1951 to 2011 respectively. The WAHL index is calculated following the method proposed by Chauvin et al. (2010) and based on NCAR/NCEP Reanalysis dataset, while the Azore High pressure system regimes variability are computed as in Davis et al. (1997). We show that a statistical relationship between heat waves in Western and Central Mediterranean Basin and WAHL mechanism exists, being the latter a prominent causal factor. The relationships and causal connections between WAHL and Azores High atmospheric systems are also analysed to highlight potential implications for heat waves outlooks and early warning systems.

  5. Solar central receiver hybrid power system, phase 1. Volume 3: Appendices

    NASA Astrophysics Data System (ADS)

    1979-09-01

    Parametric salt piping data, sample heat exchanger calculations, and salt/materials compatibility evaluations are presented. Data lists that include the heliostat field coordinates, the STEAEC program input data, the hybrid receiver design drawings and models, and the piping stress analysis are also presented.

  6. Are Ducted Mini-Splits Worth It?

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

    Winkler, Jonathan M; Maguire, Jeffrey B; Metzger, Cheryn E.

    Ducted mini-split heat pumps are gaining popularity in some regions of the country due to their energy-efficient specifications and their ability to be hidden from sight. Although product and install costs are typically higher than the ductless mini-split heat pumps, this technology is well worth the premium for some homeowners who do not like to see an indoor unit in their living area. Due to the interest in this technology by local utilities and homeowners, the Bonneville Power Administration (BPA) has funded the Pacific Northwest National Laboratory (PNNL) and the National Renewable Energy Laboratory (NREL) to develop capabilities within themore » Building Energy Optimization (BEopt) tool to model ducted mini-split heat pumps. After the fundamental capabilities were added, energy-use results could be compared to other technologies that were already in BEopt, such as zonal electric resistance heat, central air source heat pumps, and ductless mini-split heat pumps. Each of these technologies was then compared using five prototype configurations in three different BPA heating zones to determine how the ducted mini-split technology would perform under different scenarios. The result of this project was a set of EnergyPlus models representing the various prototype configurations in each climate zone. Overall, the ducted mini-split heat pumps saved about 33-60% compared to zonal electric resistance heat (with window AC systems modeled in the summer). The results also showed that the ducted mini-split systems used about 4% more energy than the ductless mini-split systems, which saved about 37-64% compared to electric zonal heat (depending on the prototype and climate).« less

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

    Akar, Sertac; Turchi, Craig

    Substantial drought and declines in potable groundwater in the United States over the last decade has increased the demand for fresh water. Desalination of saline water such as brackish surface or groundwater, seawater, brines co-produced from oil and gas operations, industrial wastewater, blow-down water from power plant cooling towers, and agriculture drainage water can reduce the volume of water that requires disposal while providing a source of high-quality fresh water for industrial or commercial use. Membrane distillation (MD) is a developing technology that uses low-temperature thermal energy for desalination. Geothermal heat can be an ideal thermal-energy source for MD desalinationmore » technology, with a target range of $1/m3 to $2/m3 for desalinated water depending on the cost of heat. Three different cases were analyzed to estimate levelized cost of heat (LCOH) for integration of MD desalination technology with low-grade geothermal heat: (1) residual heat from injection brine at a geothermal power plant, (2) heat from existing underutilized low-temperature wells, and (3) drilling new wells for low-temperature resources. The Central and Western United States have important low-temperature (<90 degrees C) geothermal resource potential with wide geographic distribution, but these resources are highly underutilized because they are inefficient for power production. According to the USGS, there are 1,075 identified low temperature hydrothermal systems, 55 low temperature sedimentary systems and 248 identified medium to high temperature geothermal systems in the United States. The estimated total beneficial heat potential from identified low temperature hydrothermal geothermal systems and residual beneficial heat from medium to high temperature systems is estimated as 36,300 MWth, which could theoretically produce 1.4 to 7 million m3/day of potable water, depending on desalination efficiency.« less

  8. Low Temperature Geothermal Resource Assessment for Membrane Distillation Desalination in the United States

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

    Akar, Sertac; Turchi, Craig

    Substantial drought and declines in potable groundwater in the United States over the last decade has increased the demand for fresh water. Desalination of saline water such as brackish surface or groundwater, seawater, brines co-produced from oil and gas operations, industrial wastewater, blow-down water from power plant cooling towers, and agriculture drainage water can reduce the volume of water that requires disposal while providing a source of high-quality fresh water for industrial or commercial use. Membrane distillation (MD) is a developing technology that uses low-temperature thermal energy for desalination. Geothermal heat can be an ideal thermal-energy source for MD desalinationmore » technology, with a target range of $1/m3 to $2/m3 for desalinated water depending on the cost of heat. Three different cases were analyzed to estimate levelized cost of heat (LCOH) for integration of MD desalination technology with low-grade geothermal heat: (1) residual heat from injection brine at a geothermal power plant, (2) heat from existing underutilized low-temperature wells, and (3) drilling new wells for low-temperature resources. The Central and Western United States have important low-temperature (<90 degrees C) geothermal resource potential with wide geographic distribution, but these resources are highly underutilized because they are inefficient for power production. According to the USGS, there are 1,075 identified low temperature hydrothermal systems, 55 low temperature sedimentary systems and 248 identified medium to high temperature geothermal systems in the United States. The estimated total beneficial heat potential from identified low temperature hydrothermal geothermal systems and residual beneficial heat from medium to high temperature systems is estimated as 36,300 MWth, which could theoretically produce 1.4 to 7 million m3/day of potable water, depending on desalination efficiency.« less

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

    C. Withers; Cummings, J.; Nigusse, B.

    A new generation of full variable-capacity, central, ducted air-conditioning (AC) and heat pump units has come on the market, and they promise to deliver increased cooling (and heating) efficiency. They are controlled differently than standard single-capacity (fixed-capacity) systems. Instead of cycling on at full capacity and then cycling off when the thermostat is satisfied, they can vary their capacity over a wide range (approximately 40% to 118% of nominal full capacity), thus staying “on” for up to twice as many hours per day compared to fixed-capacity systems of the same nominal capacity. The heating and cooling capacity is varied bymore » adjusting the indoor fan air flow rate, compressor, and refrigerant flow rate as well as the outdoor unit fan air flow rate. Note that two-stage AC or heat pump systems were not evaluated in this research effort. The term dwell is used to refer to the amount of time distributed air spends inside ductwork during space-conditioning cycles. Longer run times mean greater dwell time and therefore greater exposure to conductive gains and losses.« less

  10. Bulk ion heating with ICRF waves in tokamaks

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

    Mantsinen, M. J., E-mail: mervi.mantsinen@bsc.es; Barcelona Supercomputing Center, Barcelona; Bilato, R.

    2015-12-10

    Heating with ICRF waves is a well-established method on present-day tokamaks and one of the heating systems foreseen for ITER. However, further work is still needed to test and optimize its performance in fusion devices with metallic high-Z plasma facing components (PFCs) in preparation of ITER and DEMO operation. This is of particular importance for the bulk ion heating capabilities of ICRF waves. Efficient bulk ion heating with the standard ITER ICRF scheme, i.e. the second harmonic heating of tritium with or without {sup 3}He minority, was demonstrated in experiments carried out in deuterium-tritium plasmas on JET and TFTR andmore » is confirmed by ICRF modelling. This paper focuses on recent experiments with {sup 3}He minority heating for bulk ion heating on the ASDEX Upgrade (AUG) tokamak with ITER-relevant all-tungsten PFCs. An increase of 80% in the central ion temperature T{sub i} from 3 to 5.5 keV was achieved when 3 MW of ICRF power tuned to the central {sup 3}He ion cyclotron resonance was added to 4.5 MW of deuterium NBI. The radial gradient of the T{sub i} profile reached locally values up to about 50 keV/m and the normalized logarithmic ion temperature gradients R/LT{sub i} of about 20, which are unusually large for AUG plasmas. The large changes in the T{sub i} profiles were accompanied by significant changes in measured plasma toroidal rotation, plasma impurity profiles and MHD activity, which indicate concomitant changes in plasma properties with the application of ICRF waves. When the {sup 3}He concentration was increased above the optimum range for bulk ion heating, a weaker peaking of the ion temperature profile was observed, in line with theoretical expectations.« less

  11. TPV Systems — From Research Towards Commercialisation

    NASA Astrophysics Data System (ADS)

    Bitnar, Bernd; Durisch, Wilhelm; Waser, Alfred

    2004-11-01

    An overview on the development of thermophotovoltaic (TPV) systems heated with concentrated sunlight (STPV) and with a combustion flame (CTPV) is given. Only a few experimental works on STPV are reported. Lifetime investigations of TPV emitters in solar dish concentrators were carried out. A complete STPV system reported in the literature achieved a system efficiency below 0.1 %. In contrast to these experiments we present simulations, which show that an optimised STPV system with Yb2O3 emitter and high efficient Si solar cells is able to achieve a system efficiency in the order of 30 %. Quite more experimental results are reported for CTPV systems, but a series production and commercialisation of CTPV was not achieved, so far. An application for a CTPV system is a portable electrical power supply. The highest system efficiency reported so far is 6 %. Whether this efficiency is sufficient to successfully compete with generators driven by a gas engine or a diesel motor, remains unclear. Another application for CTPV that was reported is a gas fired stove, which produces electricity in addition to heat. The application of a CTPV system for electrically autonomous domestic central heating systems could probably result in a first commercialisation of TPV. For this application, a system efficiency in the order of 1 % is sufficient. A gas fired TPV system is presented, which uses a novel foam ceramic emitter made from Yb2O3 and commercially available Si solar cells. The proof-of-concept of this prototype CTPV system could successfully be furnished. Possible applications for this CTPV system are: electrically autonomous domestic heating systems, parking heating systems for vehicles, heaters for caravans and boats or large industrial burner systems.

  12. Space station common module thermal management: Design and construction of a test bed

    NASA Technical Reports Server (NTRS)

    Barile, R. G.

    1986-01-01

    In this project, a thermal test bed was designed, simulated, and planned for construction. The thermal system features interior and exterior thermal loads and interfacing with the central-radiator thermal bus. Components of the test bed include body mounted radiator loop with interface heat exchangers (600 Btu/hr); an internal loop with cabin air-conditioning and cold plates (3400 Btu/hr); interface heat exchangers to the central bus (13,000 Btu/hr); and provisions for new technology including advanced radiators, thermal storage, and refrigeration. The apparatus will be mounted in a chamber, heated with lamps, and tested in a vacuum chamber with LN2-cooled walls. Simulation of the test bed was accomplished using a DEC PRO 350 computer and the software package TK! olver. Key input variables were absorbed solar radiation and cold plate loads. The results indicate temperatures on the two loops will be nominal when the radiation and cold plate loads are in the range of 25% to 75% of peak loads. If all loads fall to zero, except the cabin air system which was fixed, the radiator fluid will drop below -100 F and may cause excessive pressure drop. If all loads reach 100%, the cabin air temperature could rise to 96 F.

  13. Passive restriction of blood flow and counter-current heat exchange via lingual retia in the tongue of a neonatal gray whale Eschrichtius robustus (Cetacea, Mysticeti).

    PubMed

    Ekdale, Eric G; Kienle, Sarah S

    2015-04-01

    Retia mirabilia play broad roles in cetacean physiology, including thermoregulation during feeding and pressure regulations during diving. Vascular bundles of lingual retia are described within the base of the tongue of a neonatal female gray whale (Eschrichtius robustus). Each rete consists of a central artery surrounded by four to six smaller veins. The retia and constituent vessels decrease in diameter as they extend anteriorly within the hyoglossus muscle from a position anterior to the basihyal cartilage toward the apex of the tongue. The position of the retia embedded in the hyoglossus and the anterior constriction of the vessels differs from reports of similar vascular bundles that were previously identified in gray whales. The retia likely serve as a counter-current heat exchange system to control body temperature during feeding. Cold blood flowing toward the body center within the periarterial veins would accept heat from warm blood in the central artery flowing toward the anterior end of the tongue. Although thermoregulatory systems have been identified within the mouths of a few mysticete species, the distribution of such vascular structures likely is more widespread among baleen whales than has previously been described. © 2015 Wiley Periodicals, Inc.

  14. Integrated thermal management of a hybrid electric vehicle

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

    Traci, R.M.; Acebal, R.; Mohler, T.

    1999-01-01

    A thermal management methodology, based on the Vehicle Integrated Thermal Management Analysis Code (VITMAC), has been developed for a notional vehicle employing the All-Electric Combat Vehicle (AECV) concept. AECV uses a prime power source, such as a diesel, to provide mechanical energy which is converted to electrical energy and stored in a central energy storage system consisting of flywheels, batteries and/or capacitors. The combination of prime power and stored energy powers the vehicle drive system and also advanced weapons subsystems such as an ETC or EM gun, electrically driven lasers, an EM armor system and an active suspension. Every majormore » system is electrically driven with energy reclamation when possible from braking and gun recoil. Thermal management of such a complicated energy transfer and utilization system is a major design consideration due to the substantial heat rejection requirements. In the present paper, an overall integrated thermal management system (TMS) is described which accounts for energy losses from each subsystem component, accepts the heat using multiple coolant loops and expels the heat from the vehicle. VITMAC simulations are used to design the TMS and to demonstrate that a conventional TMS approach is capable of successfully handling vehicle heat rejection requirements under stressing operational conditions.« less

  15. Complex Mobile Independent Power Station for Urban Areas

    NASA Astrophysics Data System (ADS)

    Tunik, A. A.; Tolstoy, M. Y.

    2017-11-01

    A new type of a complex mobile independent power station developed in the Department of Engineering Communications and Life-Support Systems of Irkutsk National Research Technical University, is presented in this article. This station contains only solar panel, wind turbine, accumulator, diesel generator and microbial fuel cell for to produce electric energy, heat pump and solar collector to generate heat energy and also wastewater treatment plant and new complex control system. The complex mobile independent power station is intended for full power supply of a different kind of consumers located even in remote areas thus reducing their dependence from centralized energy supply systems, decrease the fossil fuel consumption, improve the environment of urban areas and solve the problems of the purification of industrial and municipal wastewater.

  16. Electric home heating: Substitution for oil and gas

    NASA Astrophysics Data System (ADS)

    Burwell, C. C.; Devine, W. D., Jr.; Phung, D. L.

    1982-03-01

    The objective of the research is to determine the potential for substituting electricity generated with surplus coal and nuclear capacity for gas and oil used for home heating. The relative effectiveness of electric heating was determined by an analysis of the purposes of extra winter sales of electricity to the residential sector compared to a similar analysis for extra winter sales of natural gas. The price of electricity for heating is determined based on utility rate structures for selected utilities (primarily located in the north and south central portions of the country) having surplus coal and nuclear capacity throughout the decade of the 1980s. It is found that, on the average, the overall efficiency of fuel use for heating homes electrically is comparable to the use of combustion systems in the home and that electric heating is substantially less costly than direct heating with oil in regions where coal and uranium are the primary fuels used for power generation.

  17. Life expectancy impacts due to heating energy utilization in China: Distribution, relations, and policy implications.

    PubMed

    Wang, Shaobin; Luo, Kunli

    2018-01-01

    The relation between life expectancy and energy utilization is of particular concern. Different viewpoints concerned the health impacts of heating policy in China. However, it is still obscure that what kind of heating energy or what pattern of heating methods is the most related with the difference of life expectancies in China. The aim of this paper is to comprehensively investigate the spatial relations between life expectancy at birth (LEB) and different heating energy utilization in China by using spatial autocorrelation models including global spatial autocorrelation, local spatial autocorrelation and hot spot analysis. The results showed that: (1) Most of heating energy exhibit a distinct north-south difference, such as central heating supply, stalks and domestic coal. Whereas spatial distribution of domestic natural gas and electricity exhibited west-east differences. (2) Consumption of central heating, stalks and domestic coal show obvious spatial dependence. Whereas firewood, natural gas and electricity did not show significant spatial autocorrelation. It exhibited an extinct south-north difference of heat supply, stalks and domestic coal which were identified to show significant positive spatial autocorrelation. (3) Central heating, residential boilers and natural gas did not show any significant correlations with LEB. While, the utilization of domestic coal and biomass showed significant negative correlations with LEB, and household electricity shows positive correlations. The utilization of domestic coal in China showed a negative effect on LEB, rather than central heating. To improve the solid fuel stoves and control consumption of domestic coal consumption and other low quality solid fuel is imperative to improve the public health level in China in the future. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Colorado geothermal commercialization program: community development of geothermal energy in Pagosa Springs, Colorado

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

    Coe, B.A.

    1980-01-01

    A district heating system for the Pagosa Springs central business district is in the planning stage. A detailed analysis of the project is presented. It comprises area and site specific studies and describes in detail the recent, current, anticipated, and postulated geothermal development activities. (MHR)

  19. Public policy issues. A Southern California Gas Company project SAGE report

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Hirsberg, A. S.

    1978-01-01

    The use of solar energy to stretch our supplies of fossil fuels was investigated. Project SAGE (semi-automated ground environment) addresses itself to one application of this goal, solar assistance in central water heating systems for multifamily projects. Public policy issues that affect the rate of adoption of solar energy systems were investigated and policy actions were offered to accelerate the adoption of SAGE and other solar energy systems.

  20. Developing and demonstrating low-energy climate control and production techniques for greenhouse-grown citrus and ornamental crops

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

    Bodnaruk, W.H. Jr.

    1983-04-01

    The aim of this study was to develop and demonstrate low energy climate control and production techniques for greenhouse grown citrus and ornamental crops. Emphasis was placed on design, fuel efficiency and plant response to warm water soil heating systems using solar energy and LP gas. An energy requirement of 28Btus output per hour per square foot of bed space will provide soil temperature of 70/sup 0/F minimum when air temperatures are maintained at 60/sup 0/F. Soil heating to 70/sup 0/ increased rooting and growth of 8 foliage plant varieties by 25 to 45% compared to plants grown under 60/supmore » 0/F air temperature conditions. Providing soil heating, however, increased fuel consumption in the central Florida test facilities by 30% in the winters of 1980-81 and 1981-82. Solar tie-in to soil heating systems has the potential of reducing fuel usage. Solar heated water provided 4 hours of soil heating following a good collection day. Decreased in-bed pipe spacing and increased storage capacity should increase the solar percentage to 6 hours.« less

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

    Liu, Xiaobing; Zheng, O'Neill; Niu, Fuxin

    Most commercial ground source heat pump systems (GSHP) in the United States are in a distributed configuration. These systems circulate water or an anti-freeze solution through multiple heat pump units via a central pumping system, which usually uses variable speed pump(s). Variable speed pumps have potential to significantly reduce pumping energy use; however, the energy savings in reality could be far away from its potential due to improper pumping system design and controls. In this paper, a simplified hydronic pumping system was simulated with the dynamic Modelica models to evaluate three different pumping control strategies. This includes two conventional controlmore » strategies, which are to maintain a constant differential pressure across either the supply and return mains, or at the most hydraulically remote heat pump; and an innovative control strategy, which adjusts system flow rate based on the demand of each heat pump. The simulation results indicate that a significant overflow occurs at part load conditions when the variable speed pump is controlled to main a constant differential pressure across the supply and return mains of the piping system. On the other hand, an underflow occurs at part load conditions when the variable speed pump is controlled to maintain a constant differential pressure across the furthest heat pump. The flow-demand-based control can provide needed flow rate to each heat pump at any given time, and with less pumping energy use than the two conventional controls. Finally, a typical distributed GSHP system was studied to evaluate the energy saving potential of applying the flow-demand-based pumping control strategy. This case study shows that the annual pumping energy consumption can be reduced by 62% using the flow-demand-based control compared with that using the conventional pressure-based control to maintain a constant differential pressure a cross the supply and return mains.« less

  2. Estimation of the effective heating systems radius as a method of the reliability improving and energy efficiency

    NASA Astrophysics Data System (ADS)

    Akhmetova, I. G.; Chichirova, N. D.

    2017-11-01

    When conducting an energy survey of heat supply enterprise operating several boilers located not far from each other, it is advisable to assess the degree of heat supply efficiency from individual boiler, the possibility of energy consumption reducing in the whole enterprise by switching consumers to a more efficient source, to close in effective boilers. It is necessary to consider the temporal dynamics of perspective load connection, conditions in the market changes. To solve this problem the radius calculation of the effective heat supply from the thermal energy source can be used. The disadvantage of existing methods is the high complexity, the need to collect large amounts of source data and conduct a significant amount of computational efforts. When conducting an energy survey of heat supply enterprise operating a large number of thermal energy sources, rapid assessment of the magnitude of the effective heating radius requires. Taking into account the specifics of conduct and objectives of the energy survey method of calculation of effective heating systems radius, to use while conducting the energy audit should be based on data available heat supply organization in open access, minimize efforts, but the result should be to match the results obtained by other methods. To determine the efficiency radius of Kazan heat supply system were determined share of cost for generation and transmission of thermal energy, capital investment to connect new consumers. The result were compared with the values obtained with the previously known methods. The suggested Express-method allows to determine the effective radius of the centralized heat supply from heat sources, in conducting energy audits with the effort minimum and the required accuracy.

  3. Heat flow and thermotectonic problems of the central Ventura Basin, southern California

    USGS Publications Warehouse

    De Rito, R. F.; Lachenbruch, A.H.; Moses, T.H.; Munroe, R.J.

    1989-01-01

    The Ventura Basin, southern California, is located near the Big Bend area of the San Andreas fault system, within the Transverse Ranges physiographic province. Negative curvature of the Ventura Avenue temperature profiles may be explained by an increase in thermal conductivity associated with tectonic compaction of the underlying Pliocene clastic sequence. Basinwide, heat flow averages about 48 mW/m2, a value which is low relative to most of southern California. As heat flow does not vary systematically to the maximum measured depth of about 4 km, this anomly is not easily explained in terms of hydrologic effects or recent uplift and erosion. However, a diminution of heat flow is an expectable consequence of the accumulation of cold sediments (up to 12 km) since Eocene time. -from Authors

  4. Conceptual design of advanced central receiver power systems sodium-cooled receiver concept. Volume 1. Executive summary. Final report

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

    Not Available

    1979-06-01

    The conceptual design of an advanced central receiver power system using liquid sodium as a heat transport medium has been completed by a team consisting of the Energy Systems Group (prime contractor), McDonnell Douglas, Stearns-Roger, The University of Houston, and Salt River Project. The purpose of this study was to determine the technical and economic advantages of this concept for commercial-scale power plants. This final report covers all tasks of the project. These tasks were as follows: (1) review and analysis of preliminary specification; (2) parametric analysis; (3) select commercial configuration; (4) commercial plant conceptual design; (5) assessment of commercialmore » plant; (6) advanced central receiver power system development plan; (7) program plan; (8) reports and data; (9) program management; and (10) safety analysis. A programmatic overview of the accomplishments of this program is given. The 100-MW conceptual commercial plant, the 281-MW optimum plant, and the 10-MW pilot plant are described. (WHK)« less

  5. Heat capacity of a self-gravitating spherical shell of radiations

    NASA Astrophysics Data System (ADS)

    Kim, Hyeong-Chan

    2017-10-01

    We study the heat capacity of a static system of self-gravitating radiations analytically in the context of general relativity. To avoid the complexity due to a conical singularity at the center, we excise the central part and replace it with a regular spherically symmetric distribution of matters of which specifications we are not interested in. We assume that the mass inside the inner boundary and the locations of the inner and the outer boundaries are given. Then, we derive a formula relating the variations of physical parameters at the outer boundary with those at the inner boundary. Because there is only one free variation at the inner boundary, the variations at the outer boundary are related, which determines the heat capacity. To get an analytic form for the heat capacity, we use the thermodynamic identity δ Srad=β δ Mrad additionally, which is derived from the variational relation of the entropy formula with the restriction that the mass inside the inner boundary does not change. Even if the radius of the inner boundary of the shell goes to zero, in the presence of a central conical singularity, the heat capacity does not go to the form of the regular sphere. An interesting discovery is that another legitimate temperature can be defined at the inner boundary which is different from the asymptotic one β-1.

  6. Heat storage in alloy transformations

    NASA Technical Reports Server (NTRS)

    Birchenall, C. E.

    1980-01-01

    Heats of transformation of eutectic alloys were measured for many binary and ternary systems by differential scanning calorimetry and thermal analysis. Only the relatively cheap and plentiful elements Mg, Al, Si, P, Ca, Cu, Zn were considered. A method for measuring volume change during transformation was developed using x-ray absorption in a confined sample. Thermal expansion coefficients of both solid and liquid states of aluminum and of its eutectics with copper and with silicon also were determined. Preliminary evaluation of containment materials lead to the selection of silicon carbide as the initial material for study. Possible applications of alloy PCMs for heat storage in conventional and solar central power stations, small solar receivers and industrial furnace operations are under consideration.

  7. Low-temperature thermal control for a lunar base

    NASA Technical Reports Server (NTRS)

    Swanson, Theodore D.; Radermacher, Reinhard; Costello, Frederick A.; Moore, James S., Jr.; Mengers, David R.

    1990-01-01

    The generic problem of rejecting low- to moderate-temperature heat from space facilities located in a hot thermal sink environment is studied, and the example of a lunar base located near the equator is described. The effective thermal sink temperature is often above or near nominal room temperature. A three heat pump assisted thermal bus concept appears to be the most viable as they are the least sensitive to environmental conditions. Weight estimates are also developed for each of the five thermal control concepts studied: (1) 149kg/kW for a central thermal loop with unitary heat pumps; (2) 133 kg/kW for a conventional bus connected to large, central heat pumps at the radiator; (3) 134 kg/kW for a central, dual loop heat pump concept; (4) 95 kg/kW for the selective field-of-view radiator; and (5) 126 kg/kW for the regolith concept.

  8. A simulation-based study on different control strategies for variable speed pump in distributed ground source heat pump systems

    DOE PAGES

    Liu, Xiaobing; Zheng, O'Neill; Niu, Fuxin

    2016-01-01

    Most commercial ground source heat pump systems (GSHP) in the United States are in a distributed configuration. These systems circulate water or an anti-freeze solution through multiple heat pump units via a central pumping system, which usually uses variable speed pump(s). Variable speed pumps have potential to significantly reduce pumping energy use; however, the energy savings in reality could be far away from its potential due to improper pumping system design and controls. In this paper, a simplified hydronic pumping system was simulated with the dynamic Modelica models to evaluate three different pumping control strategies. This includes two conventional controlmore » strategies, which are to maintain a constant differential pressure across either the supply and return mains, or at the most hydraulically remote heat pump; and an innovative control strategy, which adjusts system flow rate based on the demand of each heat pump. The simulation results indicate that a significant overflow occurs at part load conditions when the variable speed pump is controlled to main a constant differential pressure across the supply and return mains of the piping system. On the other hand, an underflow occurs at part load conditions when the variable speed pump is controlled to maintain a constant differential pressure across the furthest heat pump. The flow-demand-based control can provide needed flow rate to each heat pump at any given time, and with less pumping energy use than the two conventional controls. Finally, a typical distributed GSHP system was studied to evaluate the energy saving potential of applying the flow-demand-based pumping control strategy. This case study shows that the annual pumping energy consumption can be reduced by 62% using the flow-demand-based control compared with that using the conventional pressure-based control to maintain a constant differential pressure a cross the supply and return mains.« less

  9. Life-threatening heat stroke presenting with ST elevations: a report of consecutive cases during the heat wave in Austria in July 2013.

    PubMed

    Lassnig, Elisabeth; Dinkhauser, Patrick; Maurer, Edwin; Eber, Bernd

    2014-08-01

    Heat stroke is a life-threatening condition due to an acute thermoregulatory failure during exposure to high environmental temperatures. We report a series of four cases (three exertional, one classic heat stroke) during the heat wave of July 2013 in Austria. All of them presented with a core temperature > 41 °C, central nervous dysfunction, acute respiratory and renal failure, disseminated intravascular coagulation, rhabdomyolysis, and severe electrocardiographic changes, two cases even mimicking ST-elevation myocardial infarction. The patients were cooled to normal temperature with the "Arctic sun" external cooling system within hours. Electrocardiographic changes resolved quickly. All patients primarily recovered from multiple organ dysfunction and could be discharged from intensive care unit. Unfortunately, the two elder patients died 1 week and 5 weeks later because of late complications.

  10. The impact of winter heating on air pollution in China.

    PubMed

    Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

    2015-01-01

    Fossil-fuel combustion related winter heating has become a major air quality and public health concern in northern China recently. We analyzed the impact of winter heating on aerosol loadings over China using the MODIS-Aqua Collection 6 aerosol product from 2004-2012. Absolute humidity (AH) and planetary boundary layer height (PBL) -adjusted aerosol optical depth (AOD*) was constructed to reflect ground-level PM2.5 concentrations. GIS analysis, standard statistical tests, and statistical modeling indicate that winter heating is an important factor causing increased PM2.5 levels in more than three-quarters of central and eastern China. The heating season AOD* was more than five times higher as the non-heating season AOD*, and the increase in AOD* in the heating areas was greater than in the non-heating areas. Finally, central heating tend to contribute less to air pollution relative to other means of household heating.

  11. The Impact of Winter Heating on Air Pollution in China

    PubMed Central

    Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

    2015-01-01

    Fossil-fuel combustion related winter heating has become a major air quality and public health concern in northern China recently. We analyzed the impact of winter heating on aerosol loadings over China using the MODIS-Aqua Collection 6 aerosol product from 2004–2012. Absolute humidity (AH) and planetary boundary layer height (PBL) -adjusted aerosol optical depth (AOD*) was constructed to reflect ground-level PM2.5 concentrations. GIS analysis, standard statistical tests, and statistical modeling indicate that winter heating is an important factor causing increased PM2.5 levels in more than three-quarters of central and eastern China. The heating season AOD* was more than five times higher as the non-heating season AOD*, and the increase in AOD* in the heating areas was greater than in the non-heating areas. Finally, central heating tend to contribute less to air pollution relative to other means of household heating. PMID:25629878

  12. Therapeutic treatment with ascorbate rescues mice from heat stroke-induced death by attenuating systemic inflammatory response and hypothalamic neuronal damage.

    PubMed

    Chang, Chia-Yu; Chen, Jen-Yin; Chen, Sheng-Hsien; Cheng, Tain-Junn; Lin, Mao-Tsun; Hu, Miao-Lin

    2016-04-01

    The impact of ascorbate on oxidative stress-related diseases is moderate because of its limited oral bioavailability and rapid clearance. However, recent evidence of the clinical benefit of parenteral vitamin C administration has emerged, especially in critical care. Heatstroke is defined as a form of excessive hyperthermia associated with a systemic inflammatory response that results in multiple organ dysfunctions in which central nervous system disorders such as delirium, convulsions, and coma are predominant. The thermoregulatory, immune, coagulation and tissue injury responses of heatstroke closely resemble those observed during sepsis and are likely mediated by similar cellular mechanisms. This study was performed by using the characteristic high lethality rate and sepsis-mimic systemic inflammatory response of a murine model of heat stroke to test our hypothesis that supra-physiological doses of ascorbate may have therapeutic use in critical care. We demonstrated that parenteral administration of ascorbate abrogated the lethality and thermoregulatory dysfunction in murine model of heat stroke by attenuating heat stroke-induced accelerated systemic inflammatory, coagulation responses and the resultant multiple organ injury, especially in hypothalamus. Overall, our findings support the hypothesis and notion that supra-physiological doses of ascorbate may have therapeutic use in critical care. Copyright © 2016. Published by Elsevier Inc.

  13. Mechanisms for eco-immunity in a changing enviroment: how does the coral innate immune system contend with climate change?

    NASA Astrophysics Data System (ADS)

    Traylor-Knowles, N. G.

    2016-02-01

    Innate immunity plays a central role in maintaining homeostasis, and within the context of impending climate change scenarios, understanding how this system works is critical. However, the actual mechanisms involved in the evolution of the innate immune system are largely unknown. Cnidaria (including corals, sea anemones and jellyfish) are well suited for studying the fundamental functions of innate immunity because they share a common ancestor with bilaterians. This study will highlight the transcriptomic changes during a heat shock in the coral Acropora hyacinthus of American Samoa, examining the temporal changes, every half an hour for 5 hours. We hypothesize that genes involved in innate immunity, and extracellular matrix maintenance will be key components to the heat stress response. This presentation will highlight the novel role of the tumor necrosis factor receptor gene family as a responder to heat stress and present future directions for this developing field in coral reef research.

  14. Intra-Sensor Variability Study of two BLS 900 Scintillometers

    NASA Astrophysics Data System (ADS)

    Thiem, Christina; Mauder, Matthias; Chwala, Christian; Bernhardt, Matthias; Kunstmann, Harald; Schulz, Karsten

    2017-04-01

    The latent heat flux is an important validation parameter for satellite measurements and a wide variety of hydrological and meteorological numerical models. Scintillometers can provide references for such validations due to their ability to spatially integrate turbulent fluxes. Large-aperture near-infrared scintillometers are capable of determining spatial averages of the structure parameter of temperature and the sensible heat flux over path lengths up to 5 km. One way to derive both sensible and latent heat flux is to use a combined optical and microwave scintillometer system. With only an optical scintillometer and additional measurements of ground heat flux and net radiation, the latent heat flux can be calculated from the residual of the energy balance. Studies have shown, however, that in certain cases measurements from the same types of scintillometers differ due to minute differences in construction. In order to prove the robustness of the measurements of two near-infrared scintillometers for future studies, we compared their observations and validated them by comparison to the sensible heat flux derived from an eddy covariance system. In this study two boundary layer scintillometers (BLS; BLS900, Scintec, Rottenburg, Germany) were installed in a central European valley as part of the TERENO preAlpine observatory during the years 2013 and 2015. An independent measurement of the sensible and latent heat flux was obtained from a permanent eddy covariance system installed in the vicinity of the scintillometer path. The structure parameter of the refractive index and average sensible heat fluxes of both BLS units were compared with each other. In general, the BLS structure parameters correlated very well and the high correlation between the BLS-derived sensible heat fluxes and the eddy covariance-derived sensible heat fluxes encouraged further application of these scintillometers in separate experiments.

  15. Improved atmosphere-ocean coupled modeling in the tropics for climate prediction

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

    Zhang, Minghua

    2015-01-01

    We investigated the initial development of the double ITCZ in the Community Climate System Model (CCSM Version 3) in the central Pacific. Starting from a resting initial condition of the ocean in January, the model developed a warm bias of sea-surface temperature (SST) in the central Pacific from 5oS to 10oS in the first three months. We found this initial bias to be caused by excessive surface shortwave radiation that is also present in the standalone atmospheric model. The initial bias is further amplified by biases in both surface latent heat flux and horizontal heat transport in the upper ocean.more » These biases are caused by the responses of surface winds to SST bias and the thermocline structure to surface wind curls. We also showed that the warming biases in surface solar radiation and latent heat fluxes are seasonally offset by cooling biases from reduced solar radiation after the austral summer due to cloud responses and in the austral fall due to enhanced evaporation when the maximum SST is closest to the equator. The warming biases from the dynamic heat transport by ocean currents however stay throughout all seasons once they are developed, which are eventually balanced by enhanced energy exchange and penetration of solar radiation below the mixed layer. Our results also showed that the equatorial cold tongue develops after the warm biases in the south central Pacific, and the overestimation of surface shortwave radiation recurs in the austral summer in each year.« less

  16. About opportunities of the sharing of city infrastructure centralized warmly - and water supply

    NASA Astrophysics Data System (ADS)

    Zamaleev, M. M.; Gubin, I. V.; Sharapov, V. I.

    2017-11-01

    It is shown that joint use of engineering infrastructure of centralized heat and water supply of consumers will be the cost-efficient decision for municipal services of the city. The new technology for regulated heating of drinking water in the condenser of steam turbines of combined heat and power plant is offered. Calculation of energy efficiency from application of new technology is executed.

  17. Circulatory failure during severe hyperthermia in dog.

    PubMed

    Miki, K; Morimoto, T; Nose, H; Itoh, T; Yamada, S

    1983-01-01

    The effect of acute hyperthermia on circulatory function was studied in 6 mongrel dogs. At a core temperature of about 40 degrees C, central venous pressure and stroke volume were maintained at almost normal level. Cardiac output significantly increased (26 ml/(kg . min)) while systemic vascular resistance significantly decreased (1.2 mmHg . sec/ml). In addition, significant decrease in vascular compliance by 40% was observed. When body temperature was raised further (severe hyperthermia), an abrupt fall of arterial pressure was observed at the rectal temperature of about 41-42 degrees C. Concomitant decreases in central venous pressure (3 mmHg), stroke volume (2.1 ml/beat) and cardiac output (29 ml/(kg . min)) were observed while heart rate increased (48 beats/min). These results suggest that the decrease in cardiac output during severe hyperthermia is due to the fall of central venous pressure, and the fall was attributed to the increase in unstressed vascular volume of systemic circulation due to the heat-induced cutaneous vasodilation. The observed decrease in systemic vascular compliance is considered to have a significant role in the maintenance of central venous pressure under hyperthermia.

  18. Experience gained from the development and results from tests of the equipment of the Kalinin NPP Unit 4 regeneration and intermediate steam separation and reheating system

    NASA Astrophysics Data System (ADS)

    Trifonov, N. N.; Sukhorukov, Yu. G.; Ermolov, V. F.; Svyatkin, F. A.; Nikolaenkova, E. K.; Sintsova, T. G.; Grigor'eva, E. B.; Esin, S. B.; Ukhanova, M. G.; Golubev, E. A.; Bik, S. P.; Tren'kin, V. B.

    2014-06-01

    The equipment of the Kalinin NPP Unit 4 regeneration, intermediate separation, and steam reheating (ISSR) systems is described and the results of their static and dynamic tests are presented. It was shown from an analysis of test results that the equipment of the regeneration and ISSR systems produce the design thermal and hydraulic characteristics in static and dynamic modes of its operation. Specialists of the Central boiler-Turbine Institute Research and Production Association have developed procedures and computer programs for calculating the system of direct-contact horizontal low-pressure heaters (connected according to the gravity circuit arrangement jointly with the second-stage electrically-driven condensate pumps) and the ISSR system, the results of which are in satisfactory agreement with experimental data. The drawbacks of the layout solutions due to which cavitation failure of the pumps may occur are considered. Technical solutions aimed at securing stable operation of the equipment of regeneration and ISSR systems are proposed. The process arrangement for heating the chamber-type high-pressure heaters adopted at the Kalinin NPP is analyzed. The version of this circuit developed at the Central Boiler-Turbine Institute Research and Production Association that allows the heating rate equal to 1°C/min to be obtained is proposed.

  19. Quantum thermodynamics of general quantum processes.

    PubMed

    Binder, Felix; Vinjanampathy, Sai; Modi, Kavan; Goold, John

    2015-03-01

    Accurately describing work extraction from a quantum system is a central objective for the extension of thermodynamics to individual quantum systems. The concepts of work and heat are surprisingly subtle when generalizations are made to arbitrary quantum states. We formulate an operational thermodynamics suitable for application to an open quantum system undergoing quantum evolution under a general quantum process by which we mean a completely positive and trace-preserving map. We derive an operational first law of thermodynamics for such processes and show consistency with the second law. We show that heat, from the first law, is positive when the input state of the map majorizes the output state. Moreover, the change in entropy is also positive for the same majorization condition. This makes a strong connection between the two operational laws of thermodynamics.

  20. 10 CFR 429.16 - Central air conditioners and heat pumps.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...-system, when combined with a selected evaporator coil (indoor unit) or a set of selected indoor units...-evaporator coil combination selected for tests pursuant to paragraph (a)(2)(i) of this section shall include the evaporator coil that is likely to have the largest volume of retail sales with the particular...

  1. 10 CFR 429.16 - Central air conditioners and heat pumps.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-system, when combined with a selected evaporator coil (indoor unit) or a set of selected indoor units...-evaporator coil combination selected for tests pursuant to paragraph (a)(2)(i) of this section shall include the evaporator coil that is likely to have the largest volume of retail sales with the particular...

  2. 10 CFR 429.16 - Central air conditioners and heat pumps.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...-system, when combined with a selected evaporator coil (indoor unit) or a set of selected indoor units...-evaporator coil combination selected for tests pursuant to paragraph (a)(2)(i) of this section shall include the evaporator coil that is likely to have the largest volume of retail sales with the particular...

  3. Process optimization of an auger pyrolyzer with heat carrier using response surface methodology.

    PubMed

    Brown, J N; Brown, R C

    2012-01-01

    A 1 kg/h auger reactor utilizing mechanical mixing of steel shot heat carrier was used to pyrolyze red oak wood biomass. Response surface methodology was employed using a circumscribed central composite design of experiments to optimize the system. Factors investigated were: heat carrier inlet temperature and mass flow rate, rotational speed of screws in the reactor, and volumetric flow rate of sweep gas. Conditions for maximum bio-oil and minimum char yields were high flow rate of sweep gas (3.5 standard L/min), high heat carrier temperature (∼600 °C), high auger speeds (63 RPM) and high heat carrier mass flow rates (18 kg/h). Regression models for bio-oil and char yields are described including identification of a novel interaction effect between heat carrier mass flow rate and auger speed. Results suggest that auger reactors, which are rarely described in literature, are well suited for bio-oil production. The reactor achieved liquid yields greater than 73 wt.%. Copyright © 2011 Elsevier Ltd. All rights reserved.

  4. Cooling apparatus with a resilient heat conducting member

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

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

    2016-06-14

    A cooling structure including a thermally conducting central element having a channel formed therein, the channel being configured for flow of cooling fluid there through, a first pressure plate, and a first thermally conductive resilient member disposed between the thermally conducting central element and the first pressure plate, wherein the first pressure plate, the first thermally conductive resilient member, and the thermally conducting central element form a first heat transfer path.

  5. Assessment of the potential of solar thermal small power systems in small utilities

    NASA Technical Reports Server (NTRS)

    Steitz, P.; Mayo, L. G.; Perkins, S. P., Jr.

    1978-01-01

    The potential economic benefit of small solar thermal electric power systems to small municipal and rural electric utilities is assessed. Five different solar thermal small power system configurations were considered in three different solar thermal technologies. The configurations included: (1) 1 MW, 2 MW, and 10 MW parabolic dish concentrators with a 15 kW heat engine mounted at the focal point of each dish, these systems utilized advanced battery energy storage; (2) a 10 MW system with variable slat concentrators and central steam Rankine energy conversion, this system utilized sensible thermal energy storage; and (3) a 50 MW central receiver system consisting of a field of heliostats concentrating energy on a tower-mounted receiver and a central steam Rankine conversion system, this system also utilized sensible thermal storage. The results are summarized in terms of break-even capital costs. The break-even capital cost was defined as the solar thermal plant capital cost which would have to be achieved in order for the solar thermal plants to penetrate 10 percent of the reference small utility generation mix by the year 2000. The calculated break-even capital costs are presented.

  6. Status of the ITER Electron Cyclotron Heating and Current Drive System

    NASA Astrophysics Data System (ADS)

    Darbos, Caroline; Albajar, Ferran; Bonicelli, Tullio; Carannante, Giuseppe; Cavinato, Mario; Cismondi, Fabio; Denisov, Grigory; Farina, Daniela; Gagliardi, Mario; Gandini, Franco; Gassmann, Thibault; Goodman, Timothy; Hanson, Gregory; Henderson, Mark A.; Kajiwara, Ken; McElhaney, Karen; Nousiainen, Risto; Oda, Yasuhisa; Omori, Toshimichi; Oustinov, Alexander; Parmar, Darshankumar; Popov, Vladimir L.; Purohit, Dharmesh; Rao, Shambhu Laxmikanth; Rasmussen, David; Rathod, Vipal; Ronden, Dennis M. S.; Saibene, Gabriella; Sakamoto, Keishi; Sartori, Filippo; Scherer, Theo; Singh, Narinder Pal; Strauß, Dirk; Takahashi, Koji

    2016-01-01

    The electron cyclotron (EC) heating and current drive (H&CD) system developed for the ITER is made of 12 sets of high-voltage power supplies feeding 24 gyrotrons connected through 24 transmission lines (TL), to five launchers, four located in upper ports and one at the equatorial level. Nearly all procurements are in-kind, following general ITER philosophy, and will come from Europe, India, Japan, Russia and the USA. The full system is designed to couple to the plasma 20 MW among the 24 MW generated power, at the frequency of 170 GHz, for various physics applications such as plasma start-up, central H&CD and magnetohydrodynamic (MHD) activity control. The design takes present day technology and extends toward high-power continuous operation, which represents a large step forward as compared to the present state of the art. The ITER EC system will be a stepping stone to future EC systems for DEMO and beyond.

  7. Latent heating characteristics of the MJO computed from TRMM Observations

    DOE PAGES

    Barnes, Hannah C.; Zuluaga, Manuel D.; Houze, Robert A.

    2015-01-14

    We report the Tropical Rainfall Measurement Mission's (TRMM) Spectral Latent Heating algorithm shows the contributions of different forms of convection to the latent heating profiles of the Madden-Julian Oscillation over the central Indian and West Pacific Oceans. In both oceanic regions, storms containing broad stratiform regions produce increased upper level heating during active Madden-Julian Oscillation (MJO) phases. The largest differences between the central Indian and West Pacific Ocean heating are associated with heating produced by convective elements. Examination of the most extreme forms of convection shows that mesoscale organized convection often produces at least as much latent heat as youngmore » vigorous deep convection. Heating from nonextreme (often midlevel-topped) convection is an important component of the MJO heating in both regions in all stages of the MJO. Over the central Indian Ocean the heating profile changes from having a maximum at 2 km due to nonextreme convection to a profile during the active stage that has two maxima: one at 3 km due to nonextreme convection and 6 km owing to numerous mature mesoscale storms with broad stratiform precipitation components. Lastly, over the West Pacific, the maxima at 3 and 6 km are present in all MJO stages, but the magnitude of the 6 km maximum sharply increases in the active MJO stage due to an increase in the number of storms with broad stratiform precipitation areas.« less

  8. Pellet injection research on the HT-6M and HT-7 tokamaks

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Bao, Yi; Li, Jiangang; Gu, Xuemao; He, Yexi

    1999-11-01

    A multishot in situ pellet injection system has been constructed in the Institute of Plasma Physics. Single- and multi-pellet injection experiments were performed on the HT-6M and superconducting HT-7 tokamaks. The system proved to be convenient and reliable to operate. Pellets were fired into ohmically and LHCD and ICRF heated plasmas. Single pellet injection in ohmic discharge was found to increase the central density of HT-7 by about one half, while two pellet injection increased the central density in a step-like fashion by one half with each shot. Peaking of the electron density profile and a hollow electron temperature profile were obtained.

  9. The 10 MWe Solar Thermal Central Receiver Pilot Plant: Solar facilities design integration. Pilot-plant station manual (RADL Item 2-1). Volume 1: System description

    NASA Astrophysics Data System (ADS)

    1982-09-01

    The complete Barstow Solar Pilot Plant is described. The plant requirements and general description are presented, the mechanical, electric power, and control and instrumentation systems as well as civil engineering and structural aspects and the station buildings are described. Included in the mechanical systems are the heliostats, receiver, thermal storage system, beam characterization system, steam, water, nitrogen, and compressed air systems, chemical feed system, fire protection system, drains, sumps and the waste disposal systems, and heating, ventilating, and air conditioning systems.

  10. Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates

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

    Lemaire, R., E-mail: romain.lemaire@mines-douai.fr; Menanteau, S.

    2016-01-15

    This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flamemore » stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>10{sup 5} K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.« less

  11. Development and numerical/experimental characterization of a lab-scale flat flame reactor allowing the analysis of pulverized solid fuel devolatilization and oxidation at high heating rates

    NASA Astrophysics Data System (ADS)

    Lemaire, R.; Menanteau, S.

    2016-01-01

    This paper deals with the thorough characterization of a new experimental test bench designed to study the devolatilization and oxidation of pulverized fuel particles in a wide range of operating conditions. This lab-scale facility is composed of a fuel feeding system, the functioning of which has been optimized by computational fluid dynamics. It allows delivering a constant and time-independent mass flow rate of fuel particles which are pneumatically transported to the central injector of a hybrid McKenna burner using a carrier gas stream that can be inert or oxidant depending on the targeted application. A premixed propane/air laminar flat flame stabilized on the porous part of the burner is used to generate the hot gases insuring the heating of the central coal/carrier-gas jet with a thermal gradient similar to those found in industrial combustors (>105 K/s). In the present work, results issued from numerical simulations performed a priori to characterize the velocity and temperature fields in the reaction chamber have been analyzed and confronted with experimental measurements carried out by coupling particle image velocimetry, thermocouple and two-color pyrometry measurements so as to validate the order of magnitude of the heating rate delivered by such a new test bench. Finally, the main features of the flat flame reactor we developed have been discussed with respect to those of another laboratory-scale system designed to study coal devolatilization at a high heating rate.

  12. Brain mediators of the effects of noxious heat on pain

    PubMed Central

    Atlas, Lauren Y.; Lindquist, Martin A.; Bolger, Niall; Wager, Tor D.

    2014-01-01

    Recent human neuroimaging studies have investigated the neural correlates of either noxious stimulus intensity or reported pain. While useful, analyzing brain relationships with stimulus intensity and behavior separately does not address how sensation and pain are linked in the central nervous system. In this paper, we used multi-level mediation analysis to identify brain mediators of pain—regions whose trial-by-trial responses to heat explained variability in the relationship between noxious stimulus intensity (across four levels) and pain. This approach has the potential to identify multiple circuits with complementary roles in pain genesis. Brain mediators of noxious heat effects on pain included targets of ascending nociceptive pathways (anterior cingulate, insula, SII, and medial thalamus) and also prefrontal and subcortical regions not associated with nociceptive pathways per se. Cluster analysis revealed that mediators were grouped into several distinct functional networks, including: a) somatosensory, paralimbic, and striatal-cerebellar networks that increased with stimulus intensity; and b) two networks co-localized with ‘default mode’ regions in which stimulus intensity-related decreases mediated increased pain. We also identified ‘thermosensory’ regions that responded to increasing noxious heat but did not predict pain reports. Finally, several regions did not respond to noxious input, but their activity predicted pain; these included ventromedial prefrontal cortex, dorsolateral prefrontal cortex, cerebellar regions, and supplementary motor cortices. These regions likely underlie both nociceptive and non-nociceptive processes that contribute to pain, such as attention and decision-making processes. Overall, these results elucidate how multiple distinct brain systems jointly contribute to the central generation of pain. PMID:24845572

  13. Convective and Stratiform Precipitation Processes and their Relationship to Latent Heating

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Lang, Steve; Zeng, Xiping; Shige, Shoichi; Takayabu, Yukari

    2009-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of its formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the Tropics. Associated with this rainfall is a vast amount of heat, which is known as latent heat. It arises mainly due to the phase change of water vapor condensing into liquid droplets; three-fourths of the total heat energy available to the Earth's atmosphere comes from tropical rainfall. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. An improved convective -stratiform heating (CSH) algorithm has been developed to obtain the 3D structure of cloud heating over the Tropics based on two sources of information: 1) rainfall information, namely its amount and the fraction due to light rain intensity, observed directly from the Precipitation Radar (PR) on board the TRMM satellite and 2) synthetic cloud physics information obtained from cloud-resolving model (CRM) simulations of cloud systems. The cloud simulations provide details on cloud processes, specifically latent heating, eddy heat flux convergence and radiative heating/cooling, that. are not directly observable by satellite. The new CSH algorithm-derived heating has a noticeably different heating structure over both ocean and land regions compared to the previous CSH algorithm. One of the major differences between new and old algorithms is that the level of maximum cloud heating occurs 1 to 1.5 km lower in the atmosphere in the new algorithm. This can effect the structure of the implied air currents associated with the general circulation of the atmosphere in the Tropics. The new CSH algorithm will be used provide retrieved heating data to other heating algorithms to supplement their performance.

  14. Solar space- and water-heating system at Stanford University. Central Food Services Building

    NASA Astrophysics Data System (ADS)

    1980-05-01

    The closed-loop drain-back system is described as offering dependability of gravity drain-back freeze protection, low maintenance, minimal costs, and simplicity. The system features an 840 square-foot collector and storage capacity of 1550 gallons. The acceptance testing and the predicted system performance data are briefly described. Solar performance calculations were performed using a computer design program (FCHART). Bidding, costs, and economics of the system are reviewed. Problems are discussed and solutions and recommendations given. An operation and maintenance manual is given.

  15. Heating of H II regions with application to the Galactic center

    NASA Technical Reports Server (NTRS)

    Maloney, Philip R.; Hollenbach, David J.; Townes, Charles H.

    1992-01-01

    The heating and thermal equilibrium of photoionized gas is reviewed. Photon-heating mechanisms (UV photoionization heating, grain photoelectric heating, and X-ray heating) either fail to provide the required heating rates or else require that the ionization state of the gas is very high. Specific application to the Galactic center observations show that the total heating power required to maintain the gas at the derived temperatures, using the observed emission measure in the bar and the temperature distribution derived from the radio recombination lines, is about 7 x 10 exp 6 solar luminosities, comparable to the bolometric luminosity of the central source as measured by the FIR flux from grains. Thus, the cooling emission from this hot gas, if LTE-derived temperatures are correct, would supply a major fraction of the bolometric and ionizing luminosity inferred from the ionized gas in the central 1 pc cavity and the dust and neutral gas in the surrounding torus.

  16. Case Study for the ARRA-funded Ground Source Heat Pump (GSHP) Demonstration at Wilders Grove Solid Waste Service Center in Raleigh, NC

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

    Liu, Xiaobing; Malhotra, Mini; Xiong, Zeyu

    High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights the findings of a case study of one of the ARRA-funded GSHP demonstration projects, a distributed GSHP system for providing all the space conditioning, outdoor air ventilation, and 100% domestic hot water tomore » the Wilders Grove Solid Waste Service Center of City of Raleigh, North Carolina. This case study is based on the analysis of measured performance data, construction costs, and simulations of the energy consumption of conventional central heating, ventilation, and air-conditioning (HVAC) systems providing the same level of space conditioning and outdoor air ventilation as the demonstrated GSHP system. The evaluated performance metrics include the energy efficiency of the heat pump equipment and the overall GSHP system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of the GSHP system compared with conventional HVAC systems. This case study also identified opportunities for reducing uncertainties in the performance evaluation and improving the operational efficiency of the demonstrated GSHP system.« less

  17. Selective Internal Heat Distribution in Modified Trombe Wall

    NASA Astrophysics Data System (ADS)

    Szyszka, Jerzy; Kogut, Janusz; Skrzypczak, Izabela; Kokoszka, Wanda

    2017-12-01

    At present, the requirements for thermal insulation of the external walls in buildings are being increased. There is a need to reduce energy consumption for heating rooms during the winter season. This may be achieved by increasing the thermal resistance of the outer partitions, using solutions that utilize either recuperation or solar radiation. The most popular systems include either solar collectors, or heat pump links or ground exchangers. Trombe walls (TW) are a very promising passive heating system, which requires little or no effort to operate, and may be very convenient in different climate conditions. A typical TW consists of a masonry wall painted a dark, heat absorbing paint colour and faced with a single or double layer of glass. The principle of operation is based on the photothermal conversion of solar radiation. There are various modifications of TW. They may improve the energy efficiency in relation to the climate conditions in which they operate. The hybrid solutions are also known. The efficiency of walls is related to the use of proper materials. In TW, the compromise should be sought between the thermal resistance and the ability to distribute heat from the absorbed energy of solar radiation. The paper presents an overview of the most commonly used solutions and discusses its own concept dedicated to the climate conditions of Central Europe.

  18. Minimizing temperature instability of heat recovery hot water system utilizing optimized thermal energy storage

    NASA Astrophysics Data System (ADS)

    Suamir, I. N.; Sukadana, I. B. P.; Arsana, M. E.

    2018-01-01

    One energy-saving technology that starts gaining attractive for hotel industry application in Indonesia is the utilization of waste heat of a central air conditioning system to heat water for domestic hot water supply system. Implementing the technology for such application at a hotel was found that hot water capacity generated from the heat recovery system could satisfy domestic hot water demand of the hotel. The gas boilers installed in order to back up the system have never been used. The hot water supply, however, was found to be instable with hot water supply temperature fluctuated ranging from 45 °C to 62 °C. The temperature fluctuations reaches 17 °C, which is considered instable and can reduce hot water usage comfort level. This research is aimed to optimize the thermal energy storage in order to minimize the temperature instability of heat recovery hot water supply system. The research is a case study approach based on cooling and hot water demands of a hotel in Jakarta-Indonesia that has applied water cooled chillers with heat recovery systems. The hotel operation with 329 guest rooms and 8 function rooms showed that hot water production in the heat recovery system completed with 5 m3 thermal energy storage (TES) could not hold the hot water supply temperature constantly. The variations of the cooling demand and hot water demands day by day were identified. It was found that there was significant mismatched of available time (hours) between cooling demand which is directly correlated to the hot water production from the heat recovery system and hot water usage. The available TES system could not store heat rejected from the condenser of the chiller during cooling demand peak time between 14.00 and 18.00 hours. The extra heat from the heat recovery system consequently increases the temperature of hot water up to 62 °C. It is about 12 K above 50 °C the requirement hot water temperature of the hotel. In contrast, the TES could not deliver proper temperature of hot water during peak hot water demand and on that time between 06.00 and 10.00 hours, the hotel also experiences a low cooling demand. Subsequently, the temperature of hot water supplied drops down as low as 45 °C. The study was found that optimization on the TES can significantly minimize temperature variation of the hot water supplied to the hotel appliances. A TES of 30 m3 storage capacity is considered the optimum capacity which can reduce the temperature fluctuation from 17 K down to 3 K. The study also found that maintaining the storage temperature relatively lower than the condenser temperature could increase hot water production of the heat recovery system.

  19. Trend of heat flow in france: relation with deep structures

    NASA Astrophysics Data System (ADS)

    Vasseur, Guy; Nouri, Yamina; Groupe Fluxchaf

    1980-06-01

    The trend of heat flow over France is discussed using both direct measurements at equilibrium in boreholes and file data. The two types of data are found to be in agreement. They exhibit high heat flow values over the Massif Central and the Vosges. An E-W cross section across the Massif Central allows us to observe the relationship between the high heat flow values, the thinning of the crust and the uprising of the asthenosphere deduced from seismic and gravity measurements. High heat flow values could be explained using a cinematic model where upward convection occurs in the upper mantle for a period of 40 m.y. with a vertical velocity reaching 5 mm/y.

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

    Barnes, Hannah C.; Zuluaga, Manuel D.; Houze, Robert A.

    We report the Tropical Rainfall Measurement Mission's (TRMM) Spectral Latent Heating algorithm shows the contributions of different forms of convection to the latent heating profiles of the Madden-Julian Oscillation over the central Indian and West Pacific Oceans. In both oceanic regions, storms containing broad stratiform regions produce increased upper level heating during active Madden-Julian Oscillation (MJO) phases. The largest differences between the central Indian and West Pacific Ocean heating are associated with heating produced by convective elements. Examination of the most extreme forms of convection shows that mesoscale organized convection often produces at least as much latent heat as youngmore » vigorous deep convection. Heating from nonextreme (often midlevel-topped) convection is an important component of the MJO heating in both regions in all stages of the MJO. Over the central Indian Ocean the heating profile changes from having a maximum at 2 km due to nonextreme convection to a profile during the active stage that has two maxima: one at 3 km due to nonextreme convection and 6 km owing to numerous mature mesoscale storms with broad stratiform precipitation components. Lastly, over the West Pacific, the maxima at 3 and 6 km are present in all MJO stages, but the magnitude of the 6 km maximum sharply increases in the active MJO stage due to an increase in the number of storms with broad stratiform precipitation areas.« less

  1. Performance outlook of the SCRAP receiver

    NASA Astrophysics Data System (ADS)

    Lubkoll, Matti; von Backström, Theodor W.; Harms, Thomas M.

    2016-05-01

    A combined cycle (CC) concentrating solar power (CSP) plant provides significant potential to achieve an efficiency increase and an electricity cost reduction compared to current single-cycle plants. A CC CSP system requires a receiver technology capable of effectively transferring heat from concentrated solar irradiation to a pressurized air stream of a gas turbine. The small number of pressurized air receivers demonstrated to date have practical limitations, when operating at high temperatures and pressures. As yet, a robust, scalable and efficient system has to be developed and commercialized. A novel receiver system, the Spiky Central Receiver Air Pre-heater (SCRAP) concept has been proposed to comply with these requirements. The SCRAP system is conceived as a solution for an efficient and robust pressurized air receiver that could be implemented in CC CSP concepts or standalone solar Brayton cycles without a bottoming Rankine cycle. The presented work expands on previous publications on the thermal modeling of the receiver system. Based on the analysis of a single heat transfer element (spike), predictions for its thermal performance can be made. To this end the existing thermal model was improved by heat transfer characteristics for the jet impingement region of the spike tip as well as heat transfer models simulating the interaction with ambient. While the jet impingement cooling effect was simulated employing a commercial CFD code, the ambient heat transfer model was based on simplifying assumptions in order to employ empirical and analytical equations. The thermal efficiency of a spike under design conditions (flux 1.0 MW/m2, air outlet temperature just below 800 °C) was calculated at approximately 80 %, where convective heat losses account for 16.2 % of the absorbed radiation and radiative heat losses for a lower 2.9 %. This effect is due to peak surface temperatures occurring at the root of the spikes. It can thus be concluded that the geometric receiver layout assists to limit radiative heat losses.

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

    Yusa, Y.; Ohsawa, S.; Kitaoka, K.

    The central part of Kyushu Island, southwest Japan, is located at the junction of the Southwest Japan Arc and the Ryukyu Arc, where a graben (Beppu-Shimabara Graben) has been formed by the rifting tectonic movement. There are many Quaternary volcanoes and active geo- and hydro-thermal fields within the Graben. The Beppu hydrothermal system extends around the Tsurumi-Garandake volcanoes at the eastern end of the Graben. This report will deal with the hydrothermal system beneath the volcanoes specially focusing on Garandake. Modest or violent fumarolic activities are visible near the summit of Garandake (1045 m in height). The total water(steam) outputmore » is 1.4 kg/s and its heat output 3.8 MW, while the heat output from the ground surface of 5.5 x 10{sup 4} m{sup 2} is 19.5 MW estimated by a heat balance analysis based on infrared radiation measurements (Yuhara et al., 1987). Thus the main process of heat discharge from Garandake, totally 23.3 MW, is the radiation from the ground surface. The geothermal gradient observed in a well drilled near the summit indicates that the large heat output is caused by some special process different from conduction because the heat flow by conduction is estimated to be 0.03 MW, which is very small compared with the observed output. Allis and Yusa (1989) suggested that a two-phase flow system is developed in Garandake. The two-phase flow, steam rising and water failing, acts as a heat pipe, by which a large quantity of (latent) heat can be transported upwards. Applying the theory of two-phase flow (Yusa and Oishi, 1989) to the Garandake system, the upflow rate of steam is estimated to be 10.3 kg/s at 100{degrees}C; the temperature near the ground surface, A part of rising steam (1.4 kg/s) flows out through fumaroles, and the remnant condenses to flow downwards. If the system is vapor-dominated, the intrinsic permeability at the shallow part should be about 1 darcy.« less

  3. Environmental Assessment of a Central Heating Plant.

    DTIC Science & Technology

    1983-02-01

    control equipment will be required. One proven system for SO2 control is flue gas desulfurization (FGt). A variety of systems are currently in use on...low sulfur coal, but it could be further reduced by flue gas desulfur - ization. This option, however, entails greater capital and operating costs and an... wet or dry. Wet processes involve contacting the flue gas with aqueous slurries or solutions of absorbents and produce liquid wastes for direct

  4. One-dimensional model and solutions for creeping gas flows in the approximation of uniform pressure

    NASA Astrophysics Data System (ADS)

    Vedernikov, A.; Balapanov, D.

    2016-11-01

    A model, along with analytical and numerical solutions, is presented to describe a wide variety of one-dimensional slow flows of compressible heat-conductive fluids. The model is based on the approximation of uniform pressure valid for the flows, in which the sound propagation time is much shorter than the duration of any meaningful density variation in the system. The energy balance is described by the heat equation that is solved independently. This approach enables the explicit solution for the fluid velocity to be obtained. Interfacial and volumetric heat and mass sources as well as boundary motion are considered as possible sources of density variation in the fluid. A set of particular tasks is analyzed for different motion sources in planar, axial, and central symmetries in the quasistationary limit of heat conduction (i.e., for large Fourier number). The analytical solutions are in excellent agreement with corresponding numerical solutions of the whole system of the Navier-Stokes equations. This work deals with the ideal gas. The approach is also valid for other equations of state.

  5. Development and validation of a predictive model for the influences of selected product and process variables on ascorbic acid degradation in simulated fruit juice.

    PubMed

    Gabriel, Alonzo A; Cayabyab, Jochelle Elysse C; Tan, Athalie Kaye L; Corook, Mark Lester F; Ables, Errol John O; Tiangson-Bayaga, Cecile Leah P

    2015-06-15

    A predictive response surface model for the influences of product (soluble solids and titratable acidity) and process (temperature and heating time) parameters on the degradation of ascorbic acid (AA) in heated simulated fruit juices (SFJs) was established. Physicochemical property ranges of freshly squeezed and processed juices, and a previously established decimal reduction times of Escherichiacoli O157:H7 at different heating temperatures were used in establishing a Central Composite Design of Experiment that determined the combinations of product and process variable used in the model building. Only the individual linear effects of temperature and heating time significantly (P<0.05) affected AA reduction (%AAr). Validating systems either over- or underestimated actual %AAr with bias factors 0.80-1.20. However, all validating systems still resulted in acceptable predictive efficacy, with accuracy factor 1.00-1.26. The model may be useful in establishing unique process schedules for specific products, for the simultaneous control and improvement of food safety and quality. Copyright © 2015 Elsevier Ltd. All rights reserved.

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

    Im, Piljae; Liu, Xiaobing

    High initial costs and lack of public awareness of ground-source heat pump (GSHP) technology are the two major barriers preventing rapid deployment of this energy-saving technology in the United States. Under the American Recovery and Reinvestment Act (ARRA), 26 GSHP projects have been competitively selected and carried out to demonstrate the benefits of GSHP systems and innovative technologies for cost reduction and/or performance improvement. This paper highlights the findings of a case study of one of the ARRA-funded GSHP demonstration projects, a ground-source variable refrigerant flow (GS-VRF) system installed at the Human Health Building at Oakland University in Rochester, Michigan.more » This case study is based on the analysis of measured performance data, maintenance records, construction costs, and simulations of the energy consumption of conventional central heating, ventilation, and air-conditioning (HVAC) systems providing the same level of space conditioning as the demonstrated GS-VRF system. The evaluated performance metrics include the energy efficiency of the heat pump equipment and the overall GS-VRF system, pumping performance, energy savings, carbon emission reductions, and cost-effectiveness of the GS-VRF system compared with conventional HVAC systems. This case study also identified opportunities for reducing uncertainties in the performance evaluation, improving the operational efficiency, and reducing the installed cost of similar GSHP systems in the future.« less

  7. Civil Engineering in Primary Schools

    ERIC Educational Resources Information Center

    Brown, Martin; Strong, Alan

    2010-01-01

    For many children of primary school age, an engineer is the man who comes to service the central heating system or who fixes the family car when it breaks down. Most have never met a "real" professional engineer, and have no idea of what is involved in the exciting world of engineering. Most assume that engineers are men. To try to…

  8. Design and Economic Analysis of a Heating/Absorption Cooling System Operating with Municipal Solid Waste Digester: A Case Study of Gazi University

    NASA Astrophysics Data System (ADS)

    Coşar, Gökhan; Pooyanfar, Mirparham; Amirabedin, Ehsan; Topal, Hüseyin

    2013-12-01

    Recovering energy from municipal solid waste (MSW) is one of the most important issues of energy management in developed countries. This raises even more interest as world fossil fuel reserves diminish and fuel prices rise. Being one of main processes of waste disposal, anaerobic digestion can be used as a means to reduce fossil fuel and electricity consumption as well as reducing emissions. With growing demand for cooling in Turkey, especially during warm seasons and considering the energy costs, utilizing heat-driven absorption cooling systems coupled with an anaerobic digester for local cooling purposes is a potentially interesting alternative for electricity driven compression cooling. The aim of this article is to study the viability of utilizing biogas obtained from MSW anaerobic digestion as the main fuel for heating facilities of Gazi University, Turkey and also the energy source for an absorption cooling system designed for the central library of the aforementioned campus. The results prove that the suggested system is sustainably and financially appealing and has the potential to replace the conventional electricity driven cooling systems with a reasonable net present worth; moreover, it can notably reduce carbon dioxide emissions.

  9. Development of a prototype two-phase thermal bus system for Space Station

    NASA Technical Reports Server (NTRS)

    Myron, D. L.; Parish, R. C.

    1987-01-01

    This paper describes the basic elements of a pumped two-phase ammonia thermal control system designed for microgravity environments, the development of the concept into a Space Station flight design, and design details of the prototype to be ground-tested in the Johnson Space Center (JSC) Thermal Test Bed. The basic system concept is one of forced-flow heat transport through interface heat exchangers with anhydrous ammonia being pumped by a device expressly designed for two-phase fluid management in reduced gravity. Control of saturation conditions, and thus system interface temperatures, is accomplished with a single central pressure regulating valve. Flow control and liquid inventory are controlled by passive, nonelectromechanical devices. Use of these simple control elements results in minimal computer controls and high system reliability. Building on the basic system concept, a brief overview of a potential Space Station flight design is given. Primary verification of the system concept will involve testing at JSC of a 25-kW ground test article currently in fabrication.

  10. Refined Three-Dimensional Modelling of Thermally-Driven Flow in the Bormio System (Central Italian Alps)

    NASA Astrophysics Data System (ADS)

    Volpi, Giorgio; Riva, Federico; Frattini, Paolo; Battista Crosta, Giovanni; Magri, Fabien

    2016-04-01

    Thermal springs are widespread in the European Alps, where more than 80 geothermal sites are known and exploited. The quantitative assessment of those thermal flow systems is a challenging issue and requires accurate conceptual model and a thorough understanding of thermo-hydraulic properties of the aquifers. Accordingly in the last years, several qualitative studies were carried out to understand the heat and fluid transport processes driving deep fluids from the reservoir to the springs. Our work focused on thermal circulation and fluid outflows of the area around Bormio (Central Italian Alps), where nine geothermal springs discharge from dolomite bodies located close to a regional alpine thrust, called the Zebrù Line. At this site, water is heated in deep circulation systems and vigorously upwells at temperature of about 40°C. The aim of this paper is to explore the mechanisms of heat and fluid transport in the Bormio area by carrying out refined steady and transient three-dimensional finite element simulations of thermally-driven flow and to quantitatively assess the source area of the thermal waters. The full regional model (ca. 700 km2) is discretized with a highly refined triangular finite element planar grid obtained with Midas GTS NX software. The structural 3D features of the regional Zebrù thrust are built by interpolating series of geological cross sections using Fracman. A script was developed to convert and implement the thrust grid into FEFLOW mesh that comprises ca. 4 million elements. The numerical results support the observed discharge rates and temperature field within the simulated domain. Flow and temperature patterns suggest that thermal groundwater flows through a deep system crossing both sedimentary and metamorphic lithotypes, and a fracture network associated to the thrust system. Besides providing a numerical framework to simulate complex fractured systems, this example gives insights into the influence of deep alpine structures on groundwater circulation that underlies the development of many hydrothermal systems.

  11. Temperature measurement systems in wearable electronics

    NASA Astrophysics Data System (ADS)

    Walczak, S.; Gołebiowski, J.

    2014-08-01

    The aim of this paper is to present the concept of temperature measurement system, adapted to wearable electronics applications. Temperature is one of the most commonly monitored factor in smart textiles, especially in sportswear, medical and rescue products. Depending on the application, measured temperature could be used as an initial value of alert, heating, lifesaving or analysis system. The concept of the temperature measurement multi-point system, which consists of flexible screen-printed resistive sensors, placed on the T-shirt connected with the central unit and the power supply is elaborated in the paper.

  12. Systematic Heat Flow Measurements Across the Wagner Basin, Northern Gulf of California

    NASA Astrophysics Data System (ADS)

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

    2017-12-01

    A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. Seismic reflection profiles show sediment in excess of 5 s two-way travel time, implying a sediment thickness of > 7 km. The heat flow profile is 40 km long, has a nominal measurement spacing of 1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Most measurements are of good quality in that the probe fully penetrated sediments and measurements were stable enough to invert for heat flow and thermal properties. We have estimated corrections for environmental perturbations due to changes in bottom water temperature and sedimentation. The mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220±60, 99±14, 1058±519 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Based on an observed fault depth of 1.75 km we estimated the maximum Darcy velocities through the western and eastern flanks as 3 and 10 cm yr-1, respectively. Heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

  13. Extension of the ECRH operational space with O2 and X3 heating schemes to control tungsten accumulation in ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Höhnle, H.; Stober, J.; Herrmann, A.; Kasparek, W.; Leuterer, F.; Monaco, F.; Neu, R.; Schmid-Lorch, D.; Schütz, H.; Schweinzer, J.; Stroth, U.; Wagner, D.; Vorbrugg, S.; Wolfrum, E.; ASDEX Upgrade Team

    2011-08-01

    ASDEX Upgrade has been operated with tungsten-coated plasma-facing components for several years. H-mode operation with good confinement has been demonstrated. Nevertheless, purely neutral beam injection-heated H-modes with reduced gas puff, moderate heating power or/and increased triangularity tend to accumulate tungsten, followed by a radiative collapse. Under these conditions, central electron heating with electron cyclotron resonance heating (ECRH), usually in X2 polarization, changes the impurity transport in the plasma centre, reducing the central tungsten concentration and, in many cases, stabilizing the plasma. In order to extend the applicability of central ECRH to a wider range of magnetic field and plasma current additional ECRH schemes with reduced single-pass absorption have been implemented: X3 heating allows us to reduce the magnetic field by 30%, such that the first H-modes with an ITER-like value of the safety factor of q95 = 3 could be run in the tungsten-coated device. O2 heating increases the cutoff density by a factor of 2 allowing higher currents and triangularities to be addressed. For both schemes, scenarios have been developed to cope with the associated reduced absorption. In the case of central X3 heating, the X2 resonance lies close to the pedestal top at the high-field side of the plasma, serving as a beam dump. For O2, holographic mirrors have been developed which guarantee a second pass through the plasma centre. The beam position on these reflectors is controlled by fast thermocouples. Stray-radiation protection has been implemented using sniffer probes.

  14. Housing conditions, respiratory illness, and lung function in children in South Wales.

    PubMed Central

    Yarnell, J W; St Leger, A S

    1977-01-01

    The hypothesis was tested that respiratory illness in children occurs more commonly in old housing than in housing built to modern standards. Three areas of housing were chosen in a South Wales valley: a recently constructed council estate with district central heating; a modern council estate heated with open coal fires; and an area of much older, traditional valley housing. Mothers reported the greatest proportion of children free of colds and sore throats during the previous 12 months in the area of traditional valley housing; mothers of children in the centrally heated estate reported the least proportion of children free of colds. Children's lung function was best in the area of traditional valley housing and worst in the centrally heated council estate. Data on demographic indices and respiratory morbidity suggest that the inhabitants of the two council estates have comparable characteristics. Another hypothesis which may explain the findings is proposed. PMID:588858

  15. Exertional heat stroke and acute liver failure: a late dysfunction

    PubMed Central

    Carvalho, Ana Sofia; Rodeia, Simão C; Silvestre, Joana; Póvoa, Pedro

    2016-01-01

    Heat stroke (HS) is defined as a severe elevation of core body temperature along with central nervous system dysfunction. Exertional heat stroke (EHS) with acute liver failure (ALF) is a rare condition. The authors report the case of a 25-year-old man with a history of cognitive enhancers’ intake who developed hyperthermia and neurological impairment while running an outdoor marathon. The patient was cooled and returned to normal body temperature after 6 h. He subsequently developed ALF and was transferred to the intensive care unit. Over-the-counter drug intake may have been related to heat intolerance and contributed to the event. The patient was successfully treated with conservative measures. In the presence of EHS, it is crucial to act promptly with aggressive total body cooling, in order to prevent progression of the clinical syndrome. Liver function must also be monitored, since it can be a late organ dysfunction. PMID:26969359

  16. Land surface and atmospheric conditions associated with heat waves over the Chickasaw Nation in the South Central United States

    NASA Astrophysics Data System (ADS)

    Lee, Eungul; Bieda, Rahama; Shanmugasundaram, Jothiganesh; Basara Richter, Heather

    2016-06-01

    Exposure to extreme heat was reconstructed based on regional land-atmosphere processes from 1979 to 2010 in the South Central U.S. The study region surrounds the Chickasaw Nation (CN), a predominantly Native American population with a highly prevalent burden of climate-sensitive chronic diseases. Land surface and atmospheric conditions for summer heat waves were analyzed during spring (March-April-May, MAM) and summer (June-July-August, JJA) based on the Climate and Ocean: Variability, Predictability, and Change maximum temperature definition for heat wave frequency (HWF). The spatial-temporal pattern of HWF was determined using empirical orthogonal function (EOF) analysis and the corresponding principle component time series of the first EOF of HWF. Statistically significant analyses of observed conditions indicated that sensible heat increased and latent heat fluxes decreased with high HWF in the South Central U.S. The largest positive correlations of sensible heat flux to HWF and the largest negative correlations of latent heat flux to HWF were specifically observed over the CN. This is a significantly different energy transfer regime due to less available soil moisture during the antecedent MAM and JJA. The higher sensible heat from dry soil could cause significant warming from the near surface (>2.0°C) to the lower troposphere (>1.5°C), and accumulated boundary layer heat could induce the significant patterns of higher geopotential height and enhance anticyclonic circulations (negative vorticity anomaly) at the midtroposphere. Results suggested a positive land-atmosphere feedback associated with heat waves and called attention to the need for region-specific climate adaptation planning.

  17. Land surface and atmospheric conditions associated with heat waves in the South Central United States

    NASA Astrophysics Data System (ADS)

    Lee, Eungul; Bieda, Rahama; Shanmugasundaram, Jothiganesh; Richter, Heather

    2017-04-01

    Exposure to extreme heat was reconstructed based on regional land-atmosphere processes from 1979 to 2010 in the South Central U.S. The study region surrounds the Chickasaw Nation (CN), a predominantly Native American population with a highly prevalent burden of climate-sensitive chronic diseases. Land surface and atmospheric conditions for summer heat waves were analyzed during spring (March-April-May, MAM) and summer (June-July-August, JJA) based on the Climate and Ocean: Variability, Predictability, and Change maximum temperature definition for heat wave frequency (HWF). The spatial-temporal pattern of HWF was determined using empirical orthogonal function (EOF) analysis and the corresponding principle component time series of the first EOF of HWF. Statistically significant analyses of observed conditions indicated that sensible heat increased and latent heat fluxes decreased with high HWF in the South Central U.S. The largest positive correlations of sensible heat flux to HWF and the largest negative correlations of latent heat flux to HWF were specifically observed over the CN. This is a significantly different energy transfer regime due to less available soil moisture during the antecedent MAM and JJA. The higher sensible heat from dry soil could cause significant warming from the near surface (> 2.0°C) to the lower troposphere (> 1.5°C), and accumulated boundary layer heat could induce the significant patterns of higher geopotential height and enhance anticyclonic circulations (negative vorticity anomaly) at the midtroposphere. Results suggested a positive land-atmosphere feedback associated with heat waves and called attention to the need for region-specific climate adaptation planning.

  18. Cooperation of Horizontal Ground Heat Exchanger with the Ventilation Unit During Summer - Case Study

    NASA Astrophysics Data System (ADS)

    Romańska-Zapała, Anna; Furtak, Marcin; Dechnik, Mirosław

    2017-10-01

    Renewable energy sources are used in the modern energy-efficient buildings to improve their energy balance. One of them is used in the mechanical ventilation system ground air heat exchanger (earth-air heat exchanger - EAHX). This solution, right after heat recovery from exhaust air (recuperation), allows the reduction in the energy needed to obtain the desired temperature of supply air. The article presents the results of "in situ" measurements of pipe ground air heat exchanger cooperating with the air handling unit, supporting cooling the building in the summer season, in Polish climatic conditions. The laboratory consists of a ventilation unit intake - exhaust with rotor for which the source of fresh air is the air intake wall and two air intakes field cooperating with the tube with ground air heat exchangers. Selection of the source of fresh air is performed using sprocket with actuators. This system is part of the ventilation system of the Malopolska Laboratory of Energy-Efficient Building (MLBE) building of Cracow University of Technology. The measuring system are, among others, the sensors of parameters of air inlets and outlets of the heat exchanger channels EAHX and weather station that senses the local weather conditions. The measurement data are recorded and archived by the integrated process control system in the building of MLBE. During the study measurements of operating parameters of the ventilation unit cooperating with the selected source of fresh air were performed. Two cases of operation of the system: using EAHX heat exchanger and without it, were analyzed. Potentially the use of ground air heat exchanger in the mechanical ventilation system can reduce the energy demand for heating or cooling rooms by the pre-adjustment of the supply air temperature. Considering the results can be concluded that the continuous use of these exchangers is not optimal. This relationship is appropriate not only on an annual basis for the transitional periods (spring and autumn), but also in individual days in the potentially most favorable periods of work exchanger (summer and winter). Inappropriate operation of the heat exchanger, will lead to a temporary increase in energy consumption for the preparation of the desired air temperature, relative to the fresh air unit which is non-pretreated. For optimal energy system operation: exchanger EAHX - air handling unit, to preserve the most favourable parameters of inlet air to handling unit, there is a need to dynamically adjust the source of fresh air, depending on changing external conditions and the required outlet temperature of central unit (temperature of air forced to the rooms).

  19. 8. Several of the rental rooms are joined by doors, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. Several of the rental rooms are joined by doors, and each room is accessed from the corridor. Originally, the transoms were glazed. When a central heating/cooling system was installed, the transoms were modified to accommodate air grilles that are supplied by a duct located in the corridor. The five-panel door and wood wainscot are original features. However, the wainscot does not occur in every room. The lath and plaster partitions and the wood flooring are typical of the original construction. Credit GADA/MRM. - Stroud Building, 31-33 North Central Avenue, Phoenix, Maricopa County, AZ

  20. Renal sympathetic nerve, blood flow, and epithelial transport responses to thermal stress.

    PubMed

    Wilson, Thad E

    2017-05-01

    Thermal stress is a profound sympathetic stress in humans; kidney responses involve altered renal sympathetic nerve activity (RSNA), renal blood flow, and renal epithelial transport. During mild cold stress, RSNA spectral power but not total activity is altered, renal blood flow is maintained or decreased, and epithelial transport is altered consistent with a sympathetic stress coupled with central volume loaded state. Hypothermia decreases RSNA, renal blood flow, and epithelial transport. During mild heat stress, RSNA is increased, renal blood flow is decreased, and epithelial transport is increased consistent with a sympathetic stress coupled with a central volume unloaded state. Hyperthermia extends these directional changes, until heat illness results. Because kidney responses are very difficult to study in humans in vivo, this review describes and qualitatively evaluates an in vivo human skin model of sympathetically regulated epithelial tissue compared to that of the nephron. This model utilizes skin responses to thermal stress, involving 1) increased skin sympathetic nerve activity (SSNA), decreased skin blood flow, and suppressed eccrine epithelial transport during cold stress; and 2) increased SSNA, skin blood flow, and eccrine epithelial transport during heat stress. This model appears to mimic aspects of the renal responses. Investigations of skin responses, which parallel certain renal responses, may aid understanding of epithelial-sympathetic nervous system interactions during cold and heat stress. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Brain mediators of the effects of noxious heat on pain.

    PubMed

    Atlas, Lauren Y; Lindquist, Martin A; Bolger, Niall; Wager, Tor D

    2014-08-01

    Recent human neuroimaging studies have investigated the neural correlates of either noxious stimulus intensity or reported pain. Although useful, analyzing brain relationships with stimulus intensity and behavior separately does not address how sensation and pain are linked in the central nervous system. In this study, we used multi-level mediation analysis to identify brain mediators of pain--regions in which trial-by-trial responses to heat explained variability in the relationship between noxious stimulus intensity (across 4 levels) and pain. This approach has the potential to identify multiple circuits with complementary roles in pain genesis. Brain mediators of noxious heat effects on pain included targets of ascending nociceptive pathways (anterior cingulate, insula, SII, and medial thalamus) and also prefrontal and subcortical regions not associated with nociceptive pathways per se. Cluster analysis revealed that mediators were grouped into several distinct functional networks, including the following: somatosensory, paralimbic, and striatal-cerebellar networks that increased with stimulus intensity; and 2 networks co-localized with "default mode" regions in which stimulus intensity-related decreases mediated increased pain. We also identified "thermosensory" regions that responded to increasing noxious heat but did not predict pain reports. Finally, several regions did not respond to noxious input, but their activity predicted pain; these included ventromedial prefrontal cortex, dorsolateral prefrontal cortex, cerebellar regions, and supplementary motor cortices. These regions likely underlie both nociceptive and non-nociceptive processes that contribute to pain, such as attention and decision-making processes. Overall, these results elucidate how multiple distinct brain systems jointly contribute to the central generation of pain. Copyright © 2014 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  2. A Geophysical Flow Experiment in a Compressible Critical Fluid

    NASA Technical Reports Server (NTRS)

    Hegseth, John; Garcia, Laudelino

    1996-01-01

    The first objective of this experiment is to build an experimental system in which, in analogy to a geophysical system, a compressible fluid in a spherical annulus becomes radially stratified in density through an A.C. electric field. When this density gradient is demonstrated, the system will be augmented so that the fluid can be driven by heating and rotation and tested in preparation for a microgravity experiment. This apparatus consists of a spherical capacitor filled with critical fluid in a temperature controlled environment. To make the fluid critical, the apparatus will be operated near the critical pressure, critical density, and critical temperature of the fluid. This will result in a highly compressible fluid because of the properties of the fluid near its critical point. A high voltage A.C. source applied across the capacitor will create a spherically symmetric central force because of the dielectric properties of the fluid in an electric field gradient. This central force will induce a spherically symmetric density gradient that is analogous to a geophysical fluid system. To generate such a density gradient the system must be small (approx. 1 inch diameter). This small cell will also be capable of driving the critical fluid by heating and rotation. Since a spherically symmetric density gradient can only be made in microgravity, another small cell, of the same geometry, will be built that uses incompressible fluid. The driving of the fluid by rotation and heating in these small cells will be developed. The resulting instabilities from the driving in these two systems will then be studied. The second objective is to study the pattern forming instabilities (bifurcations) resulting from the well controlled experimental conditions in the critical fluid cell. This experiment will come close to producing conditions that are geophysically similar and will be studied as the driving parameters are changed.

  3. The Lassen hydrothermal system

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Bergfeld, Deborah; Clor, Laura; Evans, William C.

    2016-01-01

    The active Lassen hydrothermal system includes a central vapor-dominated zone or zones beneath the Lassen highlands underlain by ~240 °C high-chloride waters that discharge at lower elevations. It is the best-exposed and largest hydrothermal system in the Cascade Range, discharging 41 ± 10 kg/s of steam (~115 MW) and 23 ± 2 kg/s of high-chloride waters (~27 MW). The Lassen system accounts for a full 1/3 of the total high-temperature hydrothermal heat discharge in the U.S. Cascades (140/400 MW). Hydrothermal heat discharge of ~140 MW can be supported by crystallization and cooling of silicic magma at a rate of ~2400 km3/Ma, and the ongoing rates of heat and magmatic CO2 discharge are broadly consistent with a petrologic model for basalt-driven magmatic evolution. The clustering of observed seismicity at ~4–5 km depth may define zones of thermal cracking where the hydrothermal system mines heat from near-plastic rock. If so, the combined areal extent of the primary heat-transfer zones is ~5 km2, the average conductive heat flux over that area is >25 W/m2, and the conductive-boundary length <50 m. Observational records of hydrothermal discharge are likely too short to document long-term transients, whether they are intrinsic to the system or owe to various geologic events such as the eruption of Lassen Peak at 27 ka, deglaciation beginning ~18 ka, the eruptions of Chaos Crags at 1.1 ka, or the minor 1914–1917 eruption at the summit of Lassen Peak. However, there is a rich record of intermittent hydrothermal measurement over the past several decades and more-frequent measurement 2009–present. These data reveal sensitivity to climate and weather conditions, seasonal variability that owes to interaction with the shallow hydrologic system, and a transient 1.5- to twofold increase in high-chloride discharge in response to an earthquake swarm in mid-November 2014.

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

    Dubin, F S; Halfon, A; Herzog, P

    The ice-generating HP-ICES uses the heat of fusion of water as a heat source for the heat pump, thus converting the water into ice. The ice will be stored in a bin and used the following summer for cooling which, therefore, could be considered a by-product of heating. The annual overall Coefficient of Performance is expected to reach a value of 4.85 and related to source energy a value of 4.85 x 0.31 = 1.5. In a detailed case study on the Market Square project in Washington, D.C., it was found that for the HP-ICES the annual source energy inputmore » is about 60% and the life cycle annual average cost is 40% of the corresponding quantities for a conventional central system with equal heating and cooling capacity. The annual average operating and administration cost for the HP-ICES is less than 70% of the corresponding costs for the conventional system, while the first cost of the HP-ICES is about 70% larger than the first cost of the conventional system. With the values assumed for the discount rate, interest rate, etc., the return on investment was found to be about 15%, which gives a discounted payback period of about 6.7 years. For the Park Plaza in Boston, the annual source energy input for the HP-ICES is 35% and the energy cost is about 30% of the corresponding quantities for the conventional system. The annual average operating and administration cost for the HP-ICES is 4.5 times as great as the first cost for the conventional system. The return on investment is 13% and the payback is 8 years. These results show that the HP-ICES can be better both in energy usage and in life cycle cost than a conventional system of the same heating and cooling capacity, and holds great promise as an energy saving system.« less

  5. Design and calibration of a novel transient radiative heat flux meter for a spacecraft thermal test

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

    Sheng, Chunchen; Hu, Peng, E-mail: hupeng@ustc.edu.cn; Cheng, Xiaofang

    2016-06-15

    Radiative heat flux measurement is significantly important for a spacecraft thermal test. To satisfy the requirements of both high accuracy and fast response, a novel transient radiative heat flux meter was developed. Its thermal receiver consists of a central thermal receiver and two thermal guarded annular plates, which ensure the temperature distribution of the central thermal receiver to be uniform enough for reasonably applying lumped heat capacity method in a transient radiative heat flux measurement. This novel transient radiative heat flux meter design can also take accurate measurements regardless of spacecraft surface temperature and incident radiation spectrum. The measurement principlemore » was elaborated and the coefficients were calibrated. Experimental results from testing a blackbody furnace and an Xenon lamp show that this novel transient radiative heat flux meter can be used to measure transient radiative heat flux up to 1400 W/m{sup 2} with high accuracy and the response time of less than 10 s.« less

  6. Neuronal nitric oxide synthase control mechanisms in the cutaneous vasculature of humans in vivo

    PubMed Central

    Kellogg, Dean L; Zhao, Joan L; Wu, Yubo

    2008-01-01

    The physiological roles of constituitively expressed nitric oxide synthase (NOS) isoforms in humans, in vivo, are unknown. Cutaneous vasodilatation during both central nervous system-mediated, thermoregulatory reflex responses to whole-body heat stress and during peripheral axon reflex-mediated, local responses to skin warming in humans depend on nitric oxide (NO) generation by constituitively expressed NOS of uncertain isoform. We hypothesized that neuronal NOS (nNOS, NOS I) effects cutaneous vasodilatation during whole-body heat stress, but not during local skin warming. We examined the effects of the nNOS inhibitor 7-nitroindazole (7-NI) administered by intradermal microdialysis on vasodilatation induced by whole-body heat stress or local skin warming. Skin blood flow (SkBF) was monitored by laser–Doppler flowmetry (LDF). Blood pressure (MAP) was monitored and cutaneous vascular conductance calculated (CVC = LDF/MAP). In protocol 1, whole-body heat stress was induced with water-perfused suits. In protocol 2, local skin warming was induced through local warming units at LDF sites. At the end of each protocol, 56 mm sodium nitroprusside was perfused at microdialysis sites to raise SkBF to maximal levels for data normalization. 7-NI significantly attenuated CVC increases during whole-body heat stress (P < 0.05), but had no effect on CVC increases induced by local skin warming (P > 0.05). These diametrically opposite effects of 7-NI on two NO-dependent processes verify selective nNOS antagonism, thus proving that the nNOS isoform affects NO increases and hence vasodilatation during centrally mediated, reflex responses to whole-body heat stress, but not during locally mediated, axon reflex responses to local skin warming. We conclude that the constituitively expressed nNOS isoform has distinct physiological roles in cardiovascular control mechanisms in humans, in vivo. PMID:18048451

  7. Effects of Elastoplastic Material Properties on Shallow Fault Slip and Surface Displacement Fields

    NASA Astrophysics Data System (ADS)

    Nevitt, J. M.; Brooks, B. A.; Minson, S. E.; Lockner, D. A.; Moore, D. E.; Ericksen, T. L.; Hudnut, K. W.; Glennie, C. L.; Madugo, C. M.

    2016-12-01

    A primary control on the geodynamics of rifting is the thermal regime. To better understand the geodynamics of rifting in the northern Gulf of California we systematically measured heat-flow across the Wagner Basin, a tectonically active basin that lies near the southern terminus of the Cerro Prieto fault. Seismic reflection profiles show sediment in excess of 5 s two-way travel time, implying a sediment thickness of > 7 km. The heat flow profile is 40 km long, has a nominal measurement spacing of 1 km, and is collocated with a seismic reflection profile. Heat flow measurements were made with a 6.5-m violin-bow probe. Most measurements are of good quality in that the probe fully penetrated sediments and measurements were stable enough to invert for heat flow and thermal properties. We have estimated corrections for environmental perturbations due to changes in bottom water temperature and sedimentation. The mean and standard deviation of heat flow across the western, central, and eastern parts of the basin are 220±60, 99±14, 1058±519 mW m-2, respectively. Corrections for sedimentation would increase measured heat flow across the central part of basin by 40 to 60%. We interpret the relatively high heat flow and large variability on the western and eastern flanks in terms of upward fluid flow at depth below the seafloor, whereas the lower and more consistent values across the central part of the basin are suggestive of conductive heat transfer. Based on an observed fault depth of 1.75 km we estimated the maximum Darcy velocities through the western and eastern flanks as 3 and 10 cm yr-1, respectively. Heat flow across the central basin is consistent with gabbroic underplating at a depth of 15 km and suggests that continental rupture here has not gone to completion.

  8. Applications of HCMM satellite data to the study of urban heating patterns

    NASA Technical Reports Server (NTRS)

    Carlson, T. N. (Principal Investigator)

    1980-01-01

    The first analyses of the Washington, D.C. area was completed in which a method was employed to determine the surface energy balance, moisture availability, and thermal inertia. Further analyses of the Clarksville, Tennessee area during project STATE were completed. To test a newly operational interactive system, a temperature study of the Central Pennsylvania Barrens was performed.

  9. Northern Hemisphere Glaciation during the Globally Warm Early Late Pliocene

    PubMed Central

    De Schepper, Stijn; Groeneveld, Jeroen; Naafs, B. David A; Van Renterghem, Cédéric; Hennissen, Jan; Head, Martin J.; Louwye, Stephen; Fabian, Karl

    2013-01-01

    The early Late Pliocene (3.6 to ∼3.0 million years ago) is the last extended interval in Earth's history when atmospheric CO2 concentrations were comparable to today's and global climate was warmer. Yet a severe global glaciation during marine isotope stage (MIS) M2 interrupted this phase of global warmth ∼3.30 million years ago, and is seen as a premature attempt of the climate system to establish an ice-age world. Here we propose a conceptual model for the glaciation and deglaciation of MIS M2 based on geochemical and palynological records from five marine sediment cores along a Caribbean to eastern North Atlantic transect. Our records show that increased Pacific-to-Atlantic flow via the Central American Seaway weakened the North Atlantic Current and attendant northward heat transport prior to MIS M2. The consequent cooling of the northern high latitude oceans permitted expansion of the continental ice sheets during MIS M2, despite near-modern atmospheric CO2 concentrations. Sea level drop during this glaciation halted the inflow of Pacific water to the Atlantic via the Central American Seaway, allowing the build-up of a Caribbean Warm Pool. Once this warm pool was large enough, the Gulf Stream–North Atlantic Current system was reinvigorated, leading to significant northward heat transport that terminated the glaciation. Before and after MIS M2, heat transport via the North Atlantic Current was crucial in maintaining warm climates comparable to those predicted for the end of this century. PMID:24349081

  10. Systems evaluation of thermal bus concepts

    NASA Technical Reports Server (NTRS)

    Stalmach, D. D.

    1982-01-01

    Thermal bus concepts, to provide a centralized thermal utility for large, multihundred kilowatt space platforms, were studied and the results are summarized. Concepts were generated, defined, and screened for inclusion in system level thermal bus trades. Parametric trade studies were conducted in order to define the operational envelope, performance, and physical characteristics of each. Two concepts were selected as offering the most promise for thermal bus development. All of four concepts involved two phase flow in order to meet the required isothermal nature of the thermal bus. Two of the concepts employ a mechanical means to circulate the working fluid, a liquid pump in one case and a vapor compressor in another. Another concept utilizes direct osmosis as the driving force of the thermal bus. The fourth concept was a high capacity monogroove heat pipe. After preliminary sizing and screening, three of these concepts were selected to carry into the trade studies. The monogroove heat pipe concept was deemed unsuitable for further consideration because of its heat transport limitations. One additional concept utilizing capillary forces to drive the working fluid was added. Parametric system level trade studies were performed. Sizing and weight calculations were performed for thermal bus sizes ranging from 5 to 350 kW and operating temperatures in the range of 4 to 120 C. System level considerations such as heat rejection and electrical power penalties and interface temperature losses were included in the weight calculations.

  11. Prospects of engineering thermotolerance in crops through modulation of heat stress transcription factor and heat shock protein networks.

    PubMed

    Fragkostefanakis, Sotirios; Röth, Sascha; Schleiff, Enrico; Scharf, Klaus-Dieter

    2015-09-01

    Cell survival under high temperature conditions involves the activation of heat stress response (HSR), which in principle is highly conserved among different organisms, but shows remarkable complexity and unique features in plant systems. The transcriptional reprogramming at higher temperatures is controlled by the activity of the heat stress transcription factors (Hsfs). Hsfs allow the transcriptional activation of HSR genes, among which heat shock proteins (Hsps) are best characterized. Hsps belong to multigene families encoding for molecular chaperones involved in various processes including maintenance of protein homeostasis as a requisite for optimal development and survival under stress conditions. Hsfs form complex networks to activate downstream responses, but are concomitantly subjected to cell-type-dependent feedback regulation through factor-specific physical and functional interactions with chaperones belonging to Hsp90, Hsp70 and small Hsp families. There is increasing evidence that the originally assumed specialized function of Hsf/chaperone networks in the HSR turns out to be a complex central stress response system that is involved in the regulation of a broad variety of other stress responses and may also have substantial impact on various developmental processes. Understanding in detail the function of such regulatory networks is prerequisite for sustained improvement of thermotolerance in important agricultural crops. © 2014 John Wiley & Sons Ltd.

  12. Iterative management of heat early warning systems in a changing climate.

    PubMed

    Hess, Jeremy J; Ebi, Kristie L

    2016-10-01

    Extreme heat is a leading weather-related cause of morbidity and mortality, with heat exposure becoming more widespread, frequent, and intense as climates change. The use of heat early warning and response systems (HEWSs) that integrate weather forecasts with risk assessment, communication, and reduction activities is increasingly widespread. HEWSs are frequently touted as an adaptation to climate change, but little attention has been paid to the question of how best to ensure effectiveness of HEWSs as climates change further. In this paper, we discuss findings showing that HEWSs satisfy the tenets of an intervention that facilitates adaptation, but climate change poses challenges infrequently addressed in heat action plans, particularly changes in the onset, duration, and intensity of dangerously warm temperatures, and changes over time in the relationships between temperature and health outcomes. Iterative management should be central to a HEWS, and iteration cycles should be of 5 years or less. Climate change adaptation and implementation science research frameworks can be used to identify HEWS modifications to improve their effectiveness as temperature continues to rise, incorporating scientific insights and new understanding of effective interventions. We conclude that, at a minimum, iterative management activities should involve planned reassessment at least every 5 years of hazard distribution, population-level vulnerability, and HEWS effectiveness. © 2016 New York Academy of Sciences.

  13. The effect of direct heating and cooling of heat regulation centers on body temperature

    NASA Technical Reports Server (NTRS)

    Barbour, H. G.

    1978-01-01

    Experiments were done on 28 rabbits in which puncture instruments were left in the brain for 1-2 days until the calori-puncture hyperthermia had passed and the body temperature was again normal. The instrument remaining in the brain was then used as a galvanic electrode and a second fever was produced, this time due to the electrical stimulus. It was concluded that heat is a centrally acting antipyretic and that cold is a centrally acting stimulus which produces hyperpyrexia cold-induced fever.

  14. Human thermoregulation and measurement of body temperature in exercise and clinical settings.

    PubMed

    Lim, Chin Leong; Byrne, Chris; Lee, Jason Kw

    2008-04-01

    This review discusses human thermoregulation during exercise and the measurement of body temperature in clinical and exercise settings. The thermoregulatory mechanisms play important roles in maintaining physiological homeostasis during rest and physical exercise. Physical exertion poses a challenge to thermoregulation by causing a substantial increase in metabolic heat production. However, within a non-thermolytic range, the thermoregulatory mechanisms are capable of adapting to sustain physiological functions under these conditions. The central nervous system may also rely on hyperthermia to protect the body from "overheating." Hyperthermia may serve as a self-limiting signal that triggers central inhibition of exercise performance when a temperature threshold is achieved. Exposure to sub-lethal heat stress may also confer tolerance against higher doses of heat stress by inducing the production of heat shock proteins, which protect cells against the thermolytic effects of heat. Advances in body temperature measurement also contribute to research in thermoregulation. Current evidence supports the use of oral temperature measurement in the clinical setting, although it may not be as convenient as tympanic temperature measurement using the infrared temperature scanner. Rectal and oesophagus temperatures are widely accepted surrogate measurements of core temperature (Tc), but they cause discomfort and are less likely to be accepted by users. Gastrointestinal temperature measurement using the ingestible temperature sensor provides an acceptable level of accuracy as a surrogate measure of Tc without causing discomfort to the user. This form of Tc measurement also allows Tc to be measured continuously in the field and has gained wider acceptance in the last decade.

  15. ION PRODUCING MECHANISM (CHARGE CUPS)

    DOEpatents

    Brobeck, W.W.

    1959-04-21

    The problems of confining a charge material in a calutron and uniformly distributing heat to the charge is described. The charge is held in a cup of thermally conductive material removably disposed within the charge chamber of the ion source block. A central thermally conducting stem is incorporated within the cup for conducting heat to the central portion of the charge contained within the cup.

  16. Heat transfer experiments with a central receiver tube subjected to unsteady and non-uniform heat flux

    NASA Astrophysics Data System (ADS)

    Fernández-Torrijos, María; Marugán-Cruz, Carolina; Sobrino, Celia; Santana, Domingo

    2017-06-01

    In this work, a molten salt test loop to study the heat transfer process in external molten salt receivers is described. The experimental installation is formed by a cylindrical molten salt tank, a pump, a flow meter, and an induction heater to generate the heat flux, which is applied in a small rectangular region of the tube surface. In central tower plants, the external receiver pipe is considered to be under unilateral concentrated solar radiation, because only one side of the pipe receives high heat flux. The main advantage of using an induction heater is the control of heating in different areas of the tube. In order to measure the effects of a non-homogenous and unsteady heat flux on the wall temperature distribution a series of experiments have been carried out. 4 K-type thermocouples have been welded at different axial and azimuthal positions of the pipe to obtain the wall temperature distribution. Different temperature measurements have been made varying the heat flux and water velocity to study their effects on the heat transfer process.

  17. Evidence that exercise-induced heat storage is dependent on adrenomedullary secretion.

    PubMed

    Rodrigues, A G; Lima, N R V; Coimbra, C C; Marubayashi, U

    2008-06-09

    To investigate the influence of medullary adrenal secretion on thermoregulation during exercise, Phy (Eserine, 5x10(-3) M) was injected into the lateral cerebral ventricle of normal (INT) or bilaterally adrenodemedullated (ADM) untrained rats. Body temperature (Tb) and metabolic rate were measured in the rats while they were exercising on a treadmill (20 m min(-1), 5% inclination) until fatigue or while they were at rest after drug injection. In resting rats, Phy increased oxygen consumption in both INT or ADM rats without any effect on core temperature. During the dynamic phase of exercise (first 20 min), ADM attenuated the exercise-induced increase in core temperature (0.86+/-0.12 degrees C ADM Sal vs 1.48+/-0.21 degrees C INT Sal), thus reducing heat storage (HS) levels. Icv injection of Phy in ADM rats significantly reduced the increase in Tb (0.012+/-0.10 degrees C min(-1) Phy vs 0.042+/-0.006 degrees C min(-1) Sal; p<0.02) and HS (65.8+/-56.1 cal Phy vs 207.7+/-32.7 cal Sal; p<0.04) compared to ADM Sal rats. In conclusion, the exercise-induced increase in heat storage was attenuated by adrenodemedullation in rats. Furthermore, the activation of heat loss mechanisms by the central cholinergic system during exercise occurs independently of adrenal medullary secretion suppression and can be improved by previous adrenodemedullation. Our data indicate the existence of a dual mechanism of heat loss control during the dynamic phase of exercise: one involving sympathoadrenal system activation that impairs heat loss and another that counteracts the increased sympathoadrenal activity through the hypothalamic cholinergic system to promote heat loss.

  18. Effects of anthropogenic heat due to air-conditioning systems on an extreme high temperature event in Hong Kong

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Li, Y.; Di Sabatino, S.; Martilli, A.; Chan, P. W.

    2018-03-01

    Anthropogenic heat flux is the heat generated by human activities in the urban canopy layer, which is considered the main contributor to the urban heat island (UHI). The UHI can in turn increase the use and energy consumption of air-conditioning systems. In this study, two effective methods for water-cooling air-conditioning systems in non-domestic areas, including the direct cooling system and central piped cooling towers (CPCTs), are physically based, parameterized, and implemented in a weather research and forecasting model at the city scale of Hong Kong. An extreme high temperature event (June 23-28, 2016) in the urban areas was examined, and we assessed the effects on the surface thermal environment, the interaction of sea-land breeze circulation and urban heat island circulation, boundary layer dynamics, and a possible reduction of energy consumption. The results showed that both water-cooled air-conditioning systems could reduce the 2 m air temperature by around 0.5 °C-0.8 °C during the daytime, and around 1.5 °C around 7:00-8:00 pm when the planetary boundary layer (PBL) height was confined to a few hundred meters. The CPCT contributed around 80%-90% latent heat flux and significantly increased the water vapor mixing ratio in the atmosphere by around 0.29 g kg-1 on average. The implementation of the two alternative air-conditioning systems could modify the heat and momentum of turbulence, which inhibited the evolution of the PBL height (a reduction of 100-150 m), reduced the vertical mixing, presented lower horizontal wind speed and buoyant production of turbulent kinetic energy, and reduced the strength of sea breeze and UHI circulation, which in turn affected the removal of air pollutants. Moreover, the two alternative air-conditioning systems could significantly reduce the energy consumption by around 30% during extreme high temperature events. The results of this study suggest potential UHI mitigation strategies and can be extended to other megacities to enable them to be more resilient to UHI effects.

  19. Modeling the Intra- and Extracellular Cytokine Signaling Pathway under Heat Stroke in the Liver

    PubMed Central

    Rodriguez-Fernandez, Maria; Grosman, Benyamin; Yuraszeck, Theresa M.; Helwig, Bryan G.; Leon, Lisa R.; Doyle III, Francis J.

    2013-01-01

    Heat stroke (HS) is a life-threatening illness induced by prolonged exposure to a hot environment that causes central nervous system abnormalities and severe hyperthermia. Current data suggest that the pathophysiological responses to heat stroke may not only be due to the immediate effects of heat exposure per se but also the result of a systemic inflammatory response syndrome (SIRS). The observation that pro- (e.g., IL-1) and anti-inflammatory (e.g., IL-10) cytokines are elevated concomitantly during recovery suggests a complex network of interactions involved in the manifestation of heat-induced SIRS. In this study, we measured a set of circulating cytokine/soluble cytokine receptor proteins and liver cytokine and receptor mRNA accumulation in wild-type and tumor necrosis factor (TNF) receptor knockout mice to assess the effect of neutralization of TNF signaling on the SIRS following HS. Using a systems approach, we developed a computational model describing dynamic changes (intra- and extracellular events) in the cytokine signaling pathways in response to HS that was fitted to novel genomic (liver mRNA accumulation) and proteomic (circulating cytokines and receptors) data using global optimization. The model allows integration of relevant biological knowledge and formulation of new hypotheses regarding the molecular mechanisms behind the complex etiology of HS that may serve as future therapeutic targets. Moreover, using our unique modeling framework, we explored cytokine signaling pathways with three in silico experiments (e.g. by simulating different heat insult scenarios and responses in cytokine knockout strains in silico). PMID:24039931

  20. VACUUM TRAP

    DOEpatents

    Gordon, H.S.

    1959-09-15

    An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

  1. Energy security of residential buildings as an aspect of managerial activity in the modern concept of globalization

    NASA Astrophysics Data System (ADS)

    Chumakova, Olga

    2017-10-01

    The paper shows the management aspects of ensuring the safety of residential buildings. The article presents an analytical review of the state of the existing heat supply systems in the Russian Federation, assesses their energy security, highlights the results of research into the causes of accidents in engineering systems in water-bearing communications, and provides methods and comparative calculations of failures of these systems. It is indicated that according to the results of the All-Russian Census of 2010, the total population of the Russian Federation at the time of the survey was 142 million 857 thousand people living in more than 1100 settlements that have the status of the city (subject to their identification by population, administrative and national economic significance and the nature of the building), as well as in almost 160,000 rural settlements. It should be noted that in accordance with the classification of settlements in the Russian Federation, there are five main categories, namely: The above classification of settlements has formed the basis for the analysis of the existing processes of functioning of the heat supply systems of the Russian Federation at the objects of housing, social and industrial development from the point of view of energy security. Thus, for example, it turned out that in large cities with multi-storey buildings the centralized heat supply system is dominated by a system consisting of one or several sources of heat, heat networks having different diameter of pipelines, their number and length, and also serving various types of heat consumers) from cogeneration plants (CHP) of public use, or industrial enterprises. As for the welterweight and small towns, including urban-type settlements with a multi-storey building of the post-war period, they, as a rule, have the majority of IGFs, fed from the city or district boiler houses.

  2. Identifying possible non-thermal effects of radio frequency energy on inactivating food microorganisms.

    PubMed

    Kou, Xiaoxi; Li, Rui; Hou, Lixia; Zhang, Lihui; Wang, Shaojin

    2018-03-23

    Radio frequency (RF) heating has been successfully used for inactivating microorganisms in agricultural and food products. Athermal (non-thermal) effects of RF energy on microorganisms have been frequently proposed in the literature, resulting in difficulties for developing effective thermal treatment protocols. The purpose of this study was to identify if the athermal inactivation of microorganisms existed during RF treatments. Escherichia coli and Staphylococcus aureus in apple juice and mashed potato were exposed to both RF and conventional thermal energies to compare their inactivation populations. A thermal death time (TDT) heating block system was used as conventional thermal energy source to simulate the same heating treatment conditions, involving heating temperature, heating rate and uniformity, of a RF treatment at a frequency of 27.12 MHz. Results showed that a similar and uniform temperature distribution in tested samples was achieved in both heating systems, so that the central sample temperature could be used as representative one for evaluating thermal inactivation of microorganisms. The survival patterns of two target microorganisms in two food samples were similar both for RF and heating block treatments since their absolute difference of survival populations was <1 log CFU/ml. The statistical analysis indicated no significant difference (P > 0.05) in inactivating bacteria between the RF and the heating block treatments at each set of temperatures. The solid temperature and microbial inactivation data demonstrated that only thermal effect of RF energy at 27.12 MHz was observed on inactivating microorganisms in foods. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. RESTful M2M Gateway for Remote Wireless Monitoring for District Central Heating Networks

    PubMed Central

    Cheng, Bo; Wei, Zesan

    2014-01-01

    In recent years, the increased interest in energy conservation and environmental protection, combined with the development of modern communication and computer technology, has resulted in the replacement of distributed heating by central heating in urban areas. This paper proposes a Representational State Transfer (REST) Machine-to-Machine (M2M) gateway for wireless remote monitoring for a district central heating network. In particular, we focus on the resource-oriented RESTful M2M gateway architecture, and present an uniform devices abstraction approach based on Open Service Gateway Initiative (OSGi) technology, and implement the resource mapping mechanism between resource address mapping mechanism between RESTful resources and the physical sensor devices, and present the buffer queue combined with polling method to implement the data scheduling and Quality of Service (QoS) guarantee, and also give the RESTful M2M gateway open service Application Programming Interface (API) set. The performance has been measured and analyzed. Finally, the conclusions and future work are presented. PMID:25436650

  4. RESTful M2M gateway for remote wireless monitoring for district central heating networks.

    PubMed

    Cheng, Bo; Wei, Zesan

    2014-11-27

    In recent years, the increased interest in energy conservation and environmental protection, combined with the development of modern communication and computer technology, has resulted in the replacement of distributed heating by central heating in urban areas. This paper proposes a Representational State Transfer (REST) Machine-to-Machine (M2M) gateway for wireless remote monitoring for a district central heating network. In particular, we focus on the resource-oriented RESTful M2M gateway architecture, and present an uniform devices abstraction approach based on Open Service Gateway Initiative (OSGi) technology, and implement the resource mapping mechanism between resource address mapping mechanism between RESTful resources and the physical sensor devices, and present the buffer queue combined with polling method to implement the data scheduling and Quality of Service (QoS) guarantee, and also give the RESTful M2M gateway open service Application Programming Interface (API) set. The performance has been measured and analyzed. Finally, the conclusions and future work are presented.

  5. Retrieved Latent Heating from TRMM

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Smith, Eric A.; Houze Jr, Robert

    2008-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of precipitation formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the tropics with the associated latent heating (LH) accounting for three-fourths of the total heat energy available to the Earth's atmosphere. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. In the last decade, it has been established that standard products of LH from satellite measurements, particularly TRMM measurements, would be a valuable resource for scientific research and applications. Such products would enable new insights and investigations concerning the complexities of convection system life cycles, the diabatic heating controls and feedbacks related to meso-synoptic circulations and their forecasting, the relationship of tropical patterns of LH to the global circulation and climate, and strategies for improving cloud parameterizations in environmental prediction models. The status of retrieved TRMM LH products, TRMM LH inter-comparison and validation project, current TRMM LH applications and critic issues/action items (based on previous five TRMM LH workshops) is presented in this article.

  6. Power-to-heat in adiabatic compressed air energy storage power plants for cost reduction and increased flexibility

    NASA Astrophysics Data System (ADS)

    Dreißigacker, Volker

    2018-04-01

    The development of new technologies for large-scale electricity storage is a key element in future flexible electricity transmission systems. Electricity storage in adiabatic compressed air energy storage (A-CAES) power plants offers the prospect of making a substantial contribution to reach this goal. This concept allows efficient, local zero-emission electricity storage on the basis of compressed air in underground caverns. The compression and expansion of air in turbomachinery help to balance power generation peaks that are not demand-driven on the one hand and consumption-induced load peaks on the other. For further improvements in cost efficiencies and flexibility, system modifications are necessary. Therefore, a novel concept regarding the integration of an electrical heating component is investigated. This modification allows increased power plant flexibilities and decreasing component sizes due to the generated high temperature heat with simultaneously decreasing total round trip efficiencies. For an exemplarily A-CAES case simulation studies regarding the electrical heating power and thermal energy storage sizes were conducted to identify the potentials in cost reduction of the central power plant components and the loss in round trip efficiency.

  7. Coherent Turbulence Rig in the Engine Research Building

    NASA Image and Video Library

    1979-08-21

    An engineer examines the Coherent Turbulence Rig in the Engine Research Building at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Coherent turbulence occurs when waves of uniform size and alignment are present in airflow. Researchers at NASA Lewis were interested in determining the relation between the size of the waves and their heat transfer properties. The massive 4.25-acre Engine Research Building contains dozens of test cells, test stands, and altitude chambers. A powerful a collection of compressors and exhausters located in the central portion of the basement provides process air and exhaust for these test areas. This system is connected to similar process air systems in the laboratory’s other large test facilities. The Central Control Room coordinates this activity and communicates with the local utilities.

  8. Life-cycle assessment of a Waste-to-Energy plant in central Norway: Current situation and effects of changes in waste fraction composition.

    PubMed

    Lausselet, Carine; Cherubini, Francesco; Del Alamo Serrano, Gonzalo; Becidan, Michael; Strømman, Anders Hammer

    2016-12-01

    Waste-to-Energy (WtE) plants constitute one of the most common waste management options to deal with municipal solid waste. WtE plants have the dual objective to reduce the amount of waste sent to landfills and simultaneously to produce useful energy (heat and/or power). Energy from WtE is gaining steadily increasing importance in the energy mix of several countries. Norway is no exception, as energy recovered from waste currently represents the main energy source of the Norwegian district heating system. Life-cycle assessments (LCA) of WtE systems in a Norwegian context are quasi-nonexistent, and this study assesses the environmental performance of a WtE plant located in central Norway by combining detailed LCA methodology with primary data from plant operations. Mass transfer coefficients and leaching coefficients are used to trace emissions over the various life-cycle stages from waste logistics to final disposal of the ashes. We consider different fractions of input waste (current waste mix, insertion of 10% car fluff, 5% clinical waste and 10% and 50% wood waste), and find a total contribution to Climate Change Impact Potential ranging from 265 to 637gCO 2 eq/kg of waste and 25 to 61gCO 2 eq/MJ of heat. The key drivers of the environmental performances of the WtE system being assessed are the carbon biogenic fraction and the lower heating value of the incoming waste, the direct emissions at the WtE plant, the leaching of the heavy metals at the landfill sites and to a lesser extent the use of consumables. We benchmark the environmental performances of our WtE systems against those of fossil energy systems, and we find better performance for the majority of environmental impact categories, including Climate Change Impact Potential, although some trade-offs exist (e.g. higher impacts on Human Toxicity Potential than natural gas, but lower than coal). Also, the insertion of challenging new waste fractions is demonstrated to be an option both to cope with the excess capacity of the Norwegian WtE sector and to reach Norway's ambitious political goals for environmentally friendly energy systems. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Stochasticity and organization of tropical convection: Role of stratiform heating in the simulation of MJO in an aquaplanet coarse resolution GCM using a stochastic multicloud parameterization

    NASA Astrophysics Data System (ADS)

    Khouider, B.; Majda, A.; Deng, Q.; Ravindran, A. M.

    2015-12-01

    Global climate models (GCMs) are large computer codes based on the discretization of the equations of atmospheric and oceanic motions coupled to various processes of transfer of heat, moisture and other constituents between land, atmosphere, and oceans. Because of computing power limitations, typical GCM grid resolution is on the order of 100 km and the effects of many physical processes, occurring on smaller scales, on the climate system are represented through various closure recipes known as parameterizations. The parameterization of convective motions and many processes associated with cumulus clouds such as the exchange of latent heat and cloud radiative forcing are believed to be behind much of uncertainty in GCMs. Based on a lattice particle interacting system, the stochastic multicloud model (SMCM) provide a novel and efficient representation of the unresolved variability in GCMs due to organized tropical convection and the cloud cover. It is widely recognized that stratiform heating contributes significantly to tropical rainfall and to the dynamics of tropical convective systems by inducing a front-to-rear tilt in the heating profile. Stratiform anvils forming in the wake of deep convection play a central role in the dynamics of tropical mesoscale convective systems. Here, aquaplanet simulations with a warm pool like surface forcing, based on a coarse-resolution GCM , of ˜170 km grid mesh, coupled with SMCM, are used to demonstrate the importance of stratiform heating for the organization of convection on planetary and intraseasonal scales. When some key model parameters are set to produce higher stratiform heating fractions, the model produces low-frequency and planetary-scale Madden Julian oscillation (MJO)-like wave disturbances while lower to moderate stratiform heating fractions yield mainly synoptic-scale convectively coupled Kelvin-like waves. Rooted from the stratiform instability, it is conjectured here that the strength and extent of stratiform downdrafts are key contributors to the scale selection of convective organizations perhaps with mechanisms that are in essence similar to those of mesoscale convective systems.

  10. JPRS report: Science and technology. Central Eurasia

    NASA Astrophysics Data System (ADS)

    1995-02-01

    Translated articles cover the following topics: laser-controlled rotary microwave waveguide junction; optical pulse-phase modulation of semiconductor laser; amplitude-phase distortions of light beam obliquely propagating through ground layer of troposphere; antenna arrays with ultrafast beam scanning; materials for a walk on moon; textile-wood-coal briquette path to capitalism; and development of automated system for scientific research and design of heat and mass transfer processes.

  11. Fungistatic activity of heat-treated flaxseed determined by response surface methodology.

    PubMed

    Xu, Y; Hall, C; Wolf-Hall, C

    2008-08-01

    The objective of this study was to evaluate the effect of heat treatment on the fungistatic activity of flaxseed (Linum usitatissimum) in potato dextrose agar (PDA) medium and a fresh noodle system. The radial growth of Penicilliumn chrysogenum, Aspergillus flavus, and a Penicillium sp. isolated from moldy noodles, as well as the mold count of fresh noodle enriched with heat treated flaxseed, were used to assess antifungal activity. A central composite design in the response surface methodology was used to predict the effect of heating temperature and time on antifungal activity of flaxseed flour (FF). Statistical analysis determined that the linear terms of both variables (that is, heating temperature and time) and the quadratic terms of the heating temperature had significant (P<0.05) effects on the radial growth of all 3 test fungi and the mold count log-cycle reduction of fresh noodle. The interactions between the temperature and time were significant for all dependent variables (P<0.05). Significant reductions in antifungal activities were found when FF was subjected to high temperatures, regardless of heating time. In contrast, prolonging the heating time did not substantially affect the antifungal activities of FF at low temperature. However, 60% of the antifungal activity was retained after FF was heated at 100 degrees C for 15 min, which suggests a potential use of FF as an antifungal additive in food products subjected to low to mild heat treatments.

  12. Effect of Running Parameters on Flow Boiling Instabilities in Microchannels.

    PubMed

    Zong, Lu-Xiang; Xu, Jin-Liang; Liu, Guo-Hua

    2015-04-01

    Flow boiling instability (FBI) in microchannels is undesirable because they can induce the mechanical vibrations and disturb the heat transfer characteristics. In this study, the synchronous optical visualization experimental system was set up. The pure acetone liquid was used as the working fluid, and the parallel triangle silicon microchannel heat sink was designed as the experimental section. With the heat flux ranging from 0-450 kW/m2 the microchannel demand average pressure drop-heater length (Δp(ave)L) curve for constant low mass flux, and the demand pressure drop-mass flux (Δp(ave)G) curve for constant length on main heater surface were obtained and studied. The effect of heat flux (q = 188.28, 256.00, and 299.87 kW/m2), length of main heater surface (L = 4.5, 6.25, and 8.00 mm), and mass flux (G = 188.97, 283.45, and 377.94 kg/m2s) on pressure drops (Ap) and temperatures at the central point of the main heater surface (Twc) were experimentally studied. The results showed that, heat flux, length of the main heater surface, and mass flux were identified as the important parameters to the boiling instability process. The boiling incipience (TBI) and critical heat flux (CHF) were early induced for the lower mass flux or the main heater surface with longer length. With heat flux increasing, the pressure drops were linearly and slightly decreased in the single liquid region but increased sharply in the two phase flow region, in which the flow boiling instabilities with apparent amplitude and long period were more easily triggered at high heat flux. Moreover, the system pressure was increased with the increase of the heat flux.

  13. UTCI-Fiala multi-node model of human heat transfer and temperature regulation

    NASA Astrophysics Data System (ADS)

    Fiala, Dusan; Havenith, George; Bröde, Peter; Kampmann, Bernhard; Jendritzky, Gerd

    2012-05-01

    The UTCI-Fiala mathematical model of human temperature regulation forms the basis of the new Universal Thermal Climate Index (UTC). Following extensive validation tests, adaptations and extensions, such as the inclusion of an adaptive clothing model, the model was used to predict human temperature and regulatory responses for combinations of the prevailing outdoor climate conditions. This paper provides an overview of the underlying algorithms and methods that constitute the multi-node dynamic UTCI-Fiala model of human thermal physiology and comfort. Treated topics include modelling heat and mass transfer within the body, numerical techniques, modelling environmental heat exchanges, thermoregulatory reactions of the central nervous system, and perceptual responses. Other contributions of this special issue describe the validation of the UTCI-Fiala model against measured data and the development of the adaptive clothing model for outdoor climates.

  14. Study of Plasma Behavior during ECRH Injection in the GAMMA 10 SMBI Experiments

    NASA Astrophysics Data System (ADS)

    Maidul Islam, Md.; Nakashima, Yousuke; Kobayashi, Shinji; Nishino, Nobuhiro; Ichimura, Kazuya; Iijima, Takaaki; Shahinul Islam, Md.; Yokodo, Takayuki; Lee, Guanyi; Yoshimoto, Tsubasa; Yamashita, Sotaro; Yoshikawa, Masayuki; Kohagura, Junko; Hirata, Mafumi; Minami, Ryutaro; Kariya, Tsuyoshi; Ikezoe, Ryuya; Ichimura, Makoto; Sakamoto, Mizuki; Imai, Tsuyoshi

    2018-01-01

    Establishment of fueling system is one of the critical issues for the future fusion reactors. Fueling experiment supersonic molecular beam injection (SMBI) have been carried out in the central-cell of GAMMA 10. In GAMMA 10, electron cyclotron resonance heating (ECRH) is used at plug/barrier-cells for the formation of the axial confining potential. Recently, ECRH was applied during SMBI to plug the loss particles and increased the plasma density in the central-cell compared to without ECRH. This result suggests that the particles are confined during SMBI due to the injection of ECRH at plug/barrier-cells in GAMMA 10.

  15. 12. DETAIL, DECORATIVE PANEL, HEAT EXCHANGER (CROPPED PRINT FROM 21/4 ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. DETAIL, DECORATIVE PANEL, HEAT EXCHANGER (CROPPED PRINT FROM 2-1/4 x 2-3/4 NEGATIVE) - U.S. General Services Administration, Central Heating Plant, C & D Streets between Twelfth & Thirteenth Streets Southwest, Washington, District of Columbia, DC

  16. Physical and chemical parameter correlations with technical and technological characteristics of heating systems and the presence of Legionella spp. in the hot water supply.

    PubMed

    Rakić, Anita; Štambuk-Giljanović, Nives

    2016-02-01

    The purpose of this study was to evaluate the prevalence of Legionella spp. and compare the quality of hot water between four facilities for accommodation located in Southern Croatia (the Split-Dalmatian County). The research included data collection on the technical and technological characteristics in the period from 2009 to 2012. The survey included a type of construction material for the distribution and internal networks, heating system water heater type, and water consumption. Changes in water quality were monitored by determination of the physical and chemical parameters (temperature, pH, free chlorine residual concentrations, iron, zinc, copper and manganese) in the samples, as well as the presence and concentration of bacteria Legionella spp. The temperature is an important factor for the development of biofilms, and it is in negative correlation with the appearance of Legionella spp. Positive correlations between the Fe and Zn concentrations and Legionella spp. were established, while the inhibitory effect of a higher Cu concentration on the Legionella spp. concentration was proven. Legionella spp. were identified in 38/126 (30.2%) of the water samples from the heating system with zinc-coated pipes, as well as in 78/299 (26.1%) of the samples from systems with plastic pipes. A similar number of Legionella spp. positive samples were established regardless of the type of the water heating system (central or independent). The study confirms the necessity of regular microbial contamination monitoring of the drinking water distribution systems (DWDSs).

  17. Computer models of complex multiloop branched pipeline systems

    NASA Astrophysics Data System (ADS)

    Kudinov, I. V.; Kolesnikov, S. V.; Eremin, A. V.; Branfileva, A. N.

    2013-11-01

    This paper describes the principal theoretical concepts of the method used for constructing computer models of complex multiloop branched pipeline networks, and this method is based on the theory of graphs and two Kirchhoff's laws applied to electrical circuits. The models make it possible to calculate velocities, flow rates, and pressures of a fluid medium in any section of pipeline networks, when the latter are considered as single hydraulic systems. On the basis of multivariant calculations the reasons for existing problems can be identified, the least costly methods of their elimination can be proposed, and recommendations for planning the modernization of pipeline systems and construction of their new sections can be made. The results obtained can be applied to complex pipeline systems intended for various purposes (water pipelines, petroleum pipelines, etc.). The operability of the model has been verified on an example of designing a unified computer model of the heat network for centralized heat supply of the city of Samara.

  18. Columbia County Habitat for Humanity Passive Townhomes

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

    Dentz, Jordan; Alaigh, Kunal; Dadia, Devanshi

    2016-03-18

    Columbia County (New York) Habitat for Humanity built a pair of townhomes to Passive House criteria with the purpose of exploring approaches for achieving Passive House performance and to eventually develop a prototype design for future projects. The project utilized a 2x6 frame wall with a structural insulated panel curtain wall and a ventilated attic over a sealed OSB ceiling air barrier. Mechanical systems include a single head, wall mounted ductless mini-split heat pump in each unit and a heat recovery ventilator. Costs were $26,000 per unit higher for Passive House construction compared with the same home built to ENERGYmore » STAR version 3 specifications, representing about 18% of total construction cost. This report discusses the cost components, energy modeling results and lessons from construction. Two alternative ventilation systems are analyzed: a central system; and, a point-source system with small through-wall units distributed throughout the house. The report includes a design and cost analysis of these two approaches.« less

  19. Building America Case Study: Columbia County Habitat for Humanity Passive Townhomes, Hudson, New York

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

    2016-04-01

    Columbia County (New York) Habitat for Humanity built a pair of townhomes to Passive House criteria with the purpose of exploring approaches for achieving Passive House performance and to eventually develop a prototype design for future projects. The project utilized a 2x6 frame wall with a structural insulated panel curtain wall and a ventilated attic over a sealed OSB ceiling air barrier. Mechanical systems include a single head, wall mounted ductless mini-split heat pump in each unit and a heat recovery ventilator. Costs were $26,000 per unit higher for Passive House construction compared with the same home built to ENERGYmore » STAR version 3 specifications, representing about 18 percent of total construction cost. This report discusses the cost components, energy modeling results and lessons from construction. Two alternative ventilation systems are analyzed: a central system; and, a point-source system with small through-wall units distributed throughout the house. The report includes a design and cost analysis of these two approaches.« less

  20. Mechanisms of thermal acclimation to exercise and heat

    NASA Technical Reports Server (NTRS)

    Nadel, E. R.; Pandolf, K. B.; Roberts, M. F.; Stolwijk, J. A. J.

    1974-01-01

    By plotting local sweating rate from a given area against the central sweating drive (which is analogous to esophageal temperature, when mean skin temperature is constant), it is possible to determine the characteristic gain constant of that area as well as its point of zero central drive. An increase in the gain constant as a result of acclimation would indicate an increased sensitivity of the sweating mechanism per unit of central sweating drive, i.e., enhanced peripheral sensitivity. A displacement of the point of zero central drive as a result of acclimation would indicate that central mechanisms are responsible for the heightened sweating response. The study was undertaken to provide information about whether central or peripheral physiological mechanisms provide for increased sweating capabilities during acclimation, and about whether the increased sweating capabilities in heat acclimation and physical training are provided for by the same mechanisms.

  1. Ground source heat pumps (GSHP) for heating and cooling in Greece

    NASA Astrophysics Data System (ADS)

    Dimera, Nikoletta

    This report presents the results of a theoretical study about the feasibility of closed loop Ground Source Heat Pumps (GSHP) for heating and cooling in Greece in terms of their impact on the capital and running costs of the building services systems of the buildings. The main aim of carrying out this study was to investigate if the heating and cooling potential of the ground could be utilized cost efficiently to serve the buildings energy demand in the Greek region. At first, an existing implementation of a closed loop GSHP system in Greece is presented and its efficiency is discussed. The aim of doing so was to understand the way of sizing such systems and the efficiency of this technology in Greek climatic and ground conditions. In a separate part of this report, the impact of different user behaviour and of various ways of sizing a GSHP system is investigated in terms of the cost impact of the examined different options as well as of their effect on the internal health and comfort conditions. After the building simulation under different scenarios, it was concluded that the user behavior - the operation of windows mostly - can result in great savings on the annual energy bills. The conclusions of this first part of the report about the user behaviour and the way of sizing GSHP systems were utilized in the next part of it, where a GSHP system is proposed for a building currently under construction in central Greece. A simple 30-year cost analysis was used in order to estimate the performance of the proposed GSHP system in economic terms and to compare it with the conventional HVAC system commonly used in Greece. According to the results of the analysis, the capital cost of installing a GSHP system for heating and cooling in buildings in Greece appears higher than the cost of conventional HVAC systems. More specifically, the capital cost of an installation for heating including gas boilers and a cooling system based on air conditioning split units is about the half of installing a GSHP system for heating and cooling designed to serve the same loads. On the other hand, if the conventional HVAC system included cooling towers instead of A/C split units, the capital cost of such the installation raises up to double the price of the GSHP system for the same needs. However, after a 30-years period of continuous use of the systems, the money spent for installing and running the GSHP system are about the half of those that should be paid once a conventional HVAC system was preferred for the same energy demand.

  2. Progress of long pulse discharges by ECH in LHD

    NASA Astrophysics Data System (ADS)

    Yoshimura, Y.; Kasahara, H.; Tokitani, M.; Sakamoto, R.; Ueda, Y.; Ito, S.; Okada, K.; Kubo, S.; Shimozuma, T.; Igami, H.; Takahashi, H.; Tsujimura, T. I.; Makino, R.; Kobayashi, S.; Mizuno, Y.; Akiyama, T.; Ashikawa, N.; Masuzaki, S.; Motojima, G.; Shoji, M.; Suzuki, C.; Tanaka, H.; Tanaka, K.; Tokuzawa, T.; Tsuchiya, H.; Yamada, I.; Goto, Y.; Yamada, H.; Mutoh, T.; Komori, A.; Takeiri, Y.; the LHD Experiment Group

    2016-04-01

    Using ion cyclotron heating and electron cyclotron heating (ECH), or solo ECH, trials of steady state plasma sustainment have been conducted in the superconducting helical/stellarator, large helical device (LHD) (Ida K et al 2015 Nucl. Fusion 55 104018). In recent years, the ECH system has been upgraded by applying newly developed 77 and 154 GHz gyrotrons. A new gas fueling system applied to the steady state operations in the LHD realized precise feedback control of the line average electron density even when the wall condition varied during long pulse discharges. Owing to these improvements in the ECH and the gas fueling systems, a stable 39 min discharge with a line average electron density n e_ave of 1.1  ×  1019 m-3, a central electron temperature T e0 of over 2.5 keV, and a central ion temperature T i0 of 1.0 keV was successfully performed with ~350 kW EC-waves. The parameters are much improved from the previous 65 min discharge with n e_ave of 0.15  ×  1019 m-3 and T e0 of 1.7 keV, and the 30 min discharge with n e_ave of 0.7  ×  1019 m-3 and T e0 of 1.7 keV.

  3. Projected techno-economic improvements for advanced solar thermal power plants

    NASA Technical Reports Server (NTRS)

    Fujita, T.; Manvi, R.; Roschke, E. J.

    1979-01-01

    The projected characteristics of solar thermal power plants (with outputs up to 10 MWe) employing promising advanced technology subsystems/components are compared to current (or pre-1985) steam-Rankine systems. Improvements accruing to advanced technology development options are delineated. The improvements derived from advanced systems result primarily from achieving high efficiencies via solar collector systems which (1) capture a large portion of the available insolation and (2) concentrate this captured solar flux to attain high temperatures required for high heat engine/energy conversion performance. The most efficient solar collector systems employ two-axis tracking. Attractive systems include the central receiver/heliostat and the parabolic dish.

  4. Positive or negative involvement of heat shock proteins in multiple sclerosis pathogenesis: an overview.

    PubMed

    Turturici, Giuseppina; Tinnirello, Rosaria; Sconzo, Gabriella; Asea, Alexzander; Savettieri, Giovanni; Ragonese, Paolo; Geraci, Fabiana

    2014-12-01

    Multiple sclerosis (MS) is the most diffuse chronic inflammatory disease of the central nervous system. Both immune-mediated and neurodegenerative processes apparently play roles in the pathogenesis of this disease. Heat shock proteins (HSPs) are a family of highly evolutionarily conserved proteins; their expression in the nervous system is induced in a variety of pathologic states, including cerebral ischemia, neurodegenerative diseases, epilepsy, and trauma. To date, investigators have observed protective effects of HSPs in a variety of brain disease models (e.g. of Alzheimer disease and Parkinson disease). In contrast, unequivocal data have been obtained for their roles in MS that depend on the HSP family and particularly on their localization (i.e. intracellular or extracellular). This article reviews our current understanding of the involvement of the principal HSP families in MS.

  5. Determination of hot-spot susceptibility of multistring photovoltaic modules in a central-station application

    NASA Technical Reports Server (NTRS)

    Gonzalez, C. C.; Weaver, R. W.; Ross, R. G., Jr.; Spencer, R.; Arnett, J. C.

    1984-01-01

    Part of the effort of the Jet Propulsion Laboratory (JPL) Flat-Plate Solar Array Project (FSA) includes a program to improve module and array reliability. A collaborative activity with industry dealing with the problem of hot-spot heating due to the shadowing of photovoltaic cells in modules and arrays containing several paralleled cell strings is described. The use of multiparallel strings in large central-station arrays introduces the likelihood of unequal current sharing and increased heating levels. Test results that relate power dissipated, current imbalance, cross-strapping frequency, and shadow configuration to hot-spot heating levels are presented. Recommendations for circuit design configurations appropriate to central-station applications that reduce the risk of hot-spot problems are offered. Guidelines are provided for developing hot-spot tests for arrays when current imbalance is a threat.

  6. Stress-induced thermotolerance of ventilatory motor pattern generation in the locust, Locusta migratoria.

    PubMed

    Newman, Amy E M; Foerster, Melody; Shoemaker, Kelly L; Robertson, R Meldrum

    2003-11-01

    Ventilation is a crucial motor activity that provides organisms with an adequate circulation of respiratory gases. For animals that exist in harsh environments, an important goal is to protect ventilation under extreme conditions. Heat shock, anoxia, and cold shock are environmental stresses that have previously been shown to trigger protective responses. We used the locust to examine stress-induced thermotolerance by monitoring the ability of the central nervous system to generate ventilatory motor patterns during a subsequent heat exposure. Preparations from pre-stressed animals had an increased incidence of motor pattern recovery following heat-induced failure, however, prior stress did not alter the characteristics of the ventilatory motor pattern. During constant heat exposure at sub-lethal temperatures, we observed a protective effect of heat shock pre-treatment. Serotonin application had similar effects on motor patterns when compared to prior heat shock. These studies are consistent with previous studies that indicate prior exposure to extreme temperatures and hypoxia can protect neural operation against high temperature stress. They further suggest that the protective mechanism is a time-dependent process best revealed during prolonged exposure to extreme temperatures and is mediated by a neuromodulator such as serotonin.

  7. Impairments in central cardiovascular function contribute to attenuated reflex vasodilation in aged skin

    PubMed Central

    Stanhewicz, Anna E.; Proctor, David N.; Alexander, Lacy M.; Kenney, W. Larry

    2015-01-01

    During supine passive heating, increases in skin blood flow (SkBF) and cardiac output (Qc) are both blunted in older adults. The aim here was to determine the effect of acutely correcting the peripheral vasodilatory capacity of aged skin on the integrated cardiovascular responses to passive heating. A secondary aim was to examine the SkBF-Qc relation during hyperthermia in the presence (upright posture) and absence (dynamic exercise) of challenges to central venous pressure. We hypothesized that greater increases in SkBF would be accompanied by greater increases in Qc. Eleven healthy older adults (69 ± 3 yr) underwent supine passive heating (0.8°C rise in core temperature; water-perfused suit) after ingesting sapropterin (BH4, a nitric oxide synthase cofactor; 10 mg/kg) or placebo (randomized double-blind crossover design). Twelve young (24 ± 1 yr) subjects served as a comparison group. SkBF (laser-Doppler flowmetry) and Qc (open-circuit acetylene wash-in) were measured during supine heating, heating + upright posture, and heating + dynamic exercise. Throughout supine and upright heating, sapropterin fully restored the SkBF response of older adults to that of young adults but Qc remained blunted. During heat + upright posture, SkBF failed to decrease in untreated older subjects. There were no age- or treatment-related differences in SkBF-Qc during dynamic exercise. The principal finding of this study was that the blunted Qc response to passive heat stress is directly related to age as opposed to the blunted peripheral vasodilatory capacity of aged skin. Furthermore, peripheral impairments to SkBF in the aged may contribute to inapposite responses during challenges to central venous pressure during hyperthermia. PMID:26494450

  8. Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation

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

    Colon, Carlos

    2017-07-01

    The Florida Solar Energy Center (FSEC) completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). The evaluation studied the performance of five hot water systems (HWS) plus a reference baseline system for each fuel, (i.e., electric and natural gas). Electric HWS consisted of two residential electric heat pump water heaters (HPWHs, 60 and 80 gallons), a solar thermal system using a polymer absorber (glazed) collector with 80-gallon storage and a duplicate 50-gallon standard electric water heater with added cap and wrap insulation. Baseline performance data were collected from amore » standard 50-gallon electric water heater of minimum code efficiency to compare energy savings. Similarly, a standard 40-gallon upright vented natural gas water heater served as baseline for the natural gas fuel category. The latter, having a larger jacket diameter [18 in., with an energy factor (EF) of 0.62] with increased insulation, replaced a former baseline (17 in. diameter, EF = 0.59) that served during three previous testing rotations (2009–2013). A high-efficiency, condensing natural gas hybrid water heater with 27-gallon buffered tank was also tested and compared against the gas baseline. All systems underwent testing simultaneously side-by-side under the criteria specified elsewhere in this report.« less

  9. Side-by-Side Testing of Water Heating Systems: Results from the 2013–2014 Evaluation

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

    Colon, Carlos

    The Florida Solar Energy Center (FSEC) completed a fourth year-long evaluation on residential hot water heating systems in a laboratory environment (east central Florida, hot-humid climate). The evaluation studied the performance of five hot water systems (HWS) plus a reference baseline system for each fuel, (i.e., electric and natural gas). Electric HWS consisted of two residential electric heat pump water heaters (HPWHs, 60 and 80 gallons), a solar thermal system using a polymer absorber (glazed) collector with 80-gallon storage and a duplicate 50-gallon standard electric water heater with added cap and wrap insulation. Baseline performance data were collected from amore » standard 50-gallon electric water heater of minimum code efficiency to compare energy savings. Similarly, a standard 40-gallon upright vented natural gas water heater served as baseline for the natural gas fuel category. The latter, having a larger jacket diameter [18 in., with an energy factor (EF) of 0.62] with increased insulation, replaced a former baseline (17 in. diameter, EF = 0.59) that served during three previous testing rotations (2009–2013). A high-efficiency, condensing natural gas hybrid water heater with 27-gallon buffered tank was also tested and compared against the gas baseline. All systems underwent testing simultaneously side-by-side under the criteria specified elsewhere in this report.« less

  10. Hydrogen turbine power conversion system assessment

    NASA Technical Reports Server (NTRS)

    Wright, D. E.; Lucci, A. D.; Campbell, J.; Lee, J. C.

    1978-01-01

    A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system.

  11. Alterations in Pain Responses in Treated and Untreated Patients with Restless Legs Syndrome: Associations with Sleep Disruption

    PubMed Central

    Edwards, Robert R; Quartana, Phillip J.; Allen, Richard P; Greenbaum, Seth; Earley, Christopher J; Smith, Michael T

    2011-01-01

    Objective There has been recent interest in characterizing potential abnormalities of pain processing in patients with sleep disorders such as Restless Legs Syndrome (RLS). The aim of this study was to evaluate psychophysical responses to noxious heat and pressure stimuli in both treated and untreated RLS patients, compared to matched controls. Methods This study is a cross-sectional group comparison of RLS patients with matched controls. A total of 31 patients (15 treated, 16 untreated) with a confirmed diagnosis of RLS were compared to 18 controls with no history of RLS or related sleep disorders. Results RLS patients (both treated and untreated) demonstrated reduced pain thresholds and reported greater clinical pain relative to controls. Moreover, RLS patients demonstrated enhanced temporal summation of heat pain (p< .05), which may reflect aberrant central nervous system facilitation of pain transmission. Both treated and untreated RLS patients reported disrupted sleep relative to controls, and mediation analyses suggested that the reduced pain thresholds in RLS were attributable to sleep disturbance. However, the effect of RLS on the magnitude of temporal summation of heat pain was independent of sleep disturbance. Conclusions These findings suggest that central nervous system pain processing may be amplified in RLS, perhaps partially as a consequence of sleep disruption. RLS patients, even those whose symptoms are managed pharmacologically, may be at elevated long-term risk for the development or maintenance of persistent pain conditions. Further studies in larger samples could help to improve the prospects for pain management in RLS patients. PMID:21570347

  12. Vertical Profiles of Latent Heat Release over the Global Tropics using TRMM Rainfall Products from December 1997 to November 2002

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.

    2003-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs. S. America ) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in stratiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMEX), Brazil in 1999 (TRMM-LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model. Review of other latent heating algorithms will be discussed in the workshop.

  13. Recovery after exercise in the heat--factors influencing fluid intake

    NASA Technical Reports Server (NTRS)

    Mack, G. W.

    1998-01-01

    The restoration of body fluid balance following dehydration induced by exercise will occur through regulatory responses which stimulate ingestion of water and sodium ions. A number of different afferent signalling systems are necessary to generate appropriate thirst or sodium appetite. The primary sensory information of naturally occurring thirst is derived from receptors sensing cell volume and the volume of the extracellular fluid compartment. Sensory information from the oropharyngeal region is also an important determinant of thirst. The interaction of these various afferent signalling systems within the central nervous system determines the extent of fluid replacement following dehydration.

  14. Thermal management system options for high power space platforms

    NASA Technical Reports Server (NTRS)

    Sadunas, J. A.; Lehtinen, A.; Parish, R.

    1985-01-01

    Thermal Management System (TMS) design options for a high power (75kWe), low earth orbit, multimodule space platform were investigated. The approach taken was to establish a baseline TMS representative of current technology, and to make incremental improvements through successive subsystem trades that lead to a candidate TMS. The TMS trades included centralized and decentralized transport, single-phase and two-phase transport, alternate working fluids, liquid loop and heat pipe radiators, deployed fixed, body mounted and steerable radiators, and thermal storage. The subsystem options were evaluated against criteria such as weight, TMS power requirement, reliability, system isothermality penalty, and growth potential.

  15. Variation of Evaporation Across a Corn-Soybean Production Region in Central Iowa

    NASA Astrophysics Data System (ADS)

    Prueger, J. H.; Hatfield, J. L.; Kustas, W. P.

    2003-12-01

    Evaporation from production corn-soybean surfaces is often assumed to be uniform across a regional extent such as the Upper Midwest in the U.S.; however, there are few direct measurements of the spatial and temporal variation of evaporation to support this assumption. During a soil moisture remote sensing study in the summer of 2002 (SMEX02), fourteen energy balance stations complete with net radiometers, soil heat flux plates, a three-dimensional sonic anemometer, and fast response CO2-H2O sensors (eddy covariance) were deployed across an 25-kilometer corn-soybean production watershed in central Iowa south of Ames, Iowa. Data were collected beginning in mid-May through August and summarized into half-hourly and daily intervals. Two intercomparisons of all eddy covariance systems were conducted, one prior to the SMEX02 study (May 2002) over an alfalfa field and one after the study over a grass surface in August (2002). The coefficient of variation among the eddy covariance instruments was less than 7%. Latent heat flux values among corn and soybean fields that were greater than 7% were considered to be real differences in evaporation among fields. Diurnal differences in net radiation and latent heat fluxes were evident among both corn and soybean fields and when seasonal totals were evaluated the differences persisted. Variation in latent heat flux among corn and soybeans was attributed to soil type, water availability and spatial variation of precipitation across the watershed. The results from fourteen eddy covariance stations provide a measure of the spatial variation in latent heat flux across a region that is considered to be relatively homogenous. This information will aid in evaluating regional evaporation models.

  16. Observationally-based Metrics of Ocean Carbon and Biogeochemical Variables are Essential for Evaluating Earth System Model Projections

    NASA Astrophysics Data System (ADS)

    Russell, J. L.; Sarmiento, J. L.

    2017-12-01

    The Southern Ocean is central to the climate's response to increasing levels of atmospheric greenhouse gases as it ventilates a large fraction of the global ocean volume. Global coupled climate models and earth system models, however, vary widely in their simulations of the Southern Ocean and its role in, and response to, the ongoing anthropogenic forcing. Due to its complex water-mass structure and dynamics, Southern Ocean carbon and heat uptake depend on a combination of winds, eddies, mixing, buoyancy fluxes and topography. Understanding how the ocean carries heat and carbon into its interior and how the observed wind changes are affecting this uptake is essential to accurately projecting transient climate sensitivity. Observationally-based metrics are critical for discerning processes and mechanisms, and for validating and comparing climate models. As the community shifts toward Earth system models with explicit carbon simulations, more direct observations of important biogeochemical parameters, like those obtained from the biogeochemically-sensored floats that are part of the Southern Ocean Carbon and Climate Observations and Modeling project, are essential. One goal of future observing systems should be to create observationally-based benchmarks that will lead to reducing uncertainties in climate projections, and especially uncertainties related to oceanic heat and carbon uptake.

  17. Heat killed Saccharomyces cerevisiae as an adjuvant for the induction of vaccine-mediated immunity against infection with Mycobacterium tuberculosis.

    PubMed

    Grover, Ajay; McLean, Jennifer L; Troudt, JoLynn M; Foster, Chad; Izzo, Linda; Creissen, Elisabeth; MacDonald, Elisabeth; Troy, Amber; Izzo, Angelo A

    2016-05-27

    The use of novel vaccine delivery systems allows for the manipulation of the adaptive immune systems through the use of molecular adjuvants that target specific innate pathways. Such strategies have been used extensively for vaccines against cancer and multiple pathogens such as Mycobacterium tuberculosis. In the current study we used heat killed non-pathogenic recombinant Saccharomyces cerevisiae expressing M. tuberculosis antigen Rv1886c (fbpB, mpt59, Ag85B) as a delivery system in conjunction with its ability to stimulate innate immunity to determine its ability to induce immunity. We established that the recombinant yeast induced activated antigen specific T cells are capable of reducing the mycobacterial burden. Inoculation of the recombinant yeast after vaccination with BCG resulted in a systemic alteration of the phenotype of the immune response although this was not reflected in an increase in the reduction of the mycobacterial burden. Taken together the data suggest that heat killed yeast can induce multiple cytokines required for induction of protective immunity and can function as a vehicle for delivery of M. tuberculosis antigens in a vaccine formulation. In addition, while it can enhance the effector memory response induced by BCG, it had little effect on central memory responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Adaptability of optimization concept in the context of cryogenic distribution for superconducting magnets of fusion machine

    NASA Astrophysics Data System (ADS)

    Sarkar, Biswanath; Bhattacharya, Ritendra Nath; Vaghela, Hitensinh; Shah, Nitin Dineshkumar; Choukekar, Ketan; Badgujar, Satish

    2012-06-01

    Cryogenic distribution system (CDS) plays a vital role for reliable operation of largescale fusion machines in a Tokamak configuration. Managing dynamic heat loads from the superconducting magnets, namely, toroidal field, poloidal field, central solenoid and supporting structure is the most important function of the CDS along with the static heat loads. Two concepts are foreseen for the configuration of the CDS: singular distribution and collective distribution. In the first concept, each magnet is assigned with one distribution box having its own sub-cooler bath. In the collective concept, it is possible to share one common bath for more than one magnet system. The case study has been performed with an identical dynamic heat load profile applied to both concepts in the same time domain. The choices of a combined system from the magnets are also part of the study without compromising the system functionality. Process modeling and detailed simulations have been performed for both the options using Aspen HYSYS®. Multiple plasma pulses per day have been considered to verify the residual energy deposited in the superconducting magnets at the end of the plasma pulse. Preliminary 3D modeling using CATIA® has been performed along with the first level of component sizing.

  19. Three-dimensional control of crystal growth using magnetic fields

    NASA Astrophysics Data System (ADS)

    Dulikravich, George S.; Ahuja, Vineet; Lee, Seungsoo

    1993-07-01

    Two coupled systems of partial differential equations governing three-dimensional laminar viscous flow undergoing solidification or melting under the influence of arbitrarily oriented externally applied magnetic fields have been formulated. The model accounts for arbitrary temperature dependence of physical properties including latent heat release, effects of Joule heating, magnetic field forces, and mushy region existence. On the basis of this model a numerical algorithm has been developed and implemented using central differencing on a curvilinear boundary-conforming grid and Runge-Kutta explicit time-stepping. The numerical results clearly demonstrate possibilities for active and practically instantaneous control of melt/solid interface shape, the solidification/melting front propagation speed, and the amount and location of solid accrued.

  20. JPRS report: Science and technology. Central Eurasia: Engineering and equipment

    NASA Astrophysics Data System (ADS)

    1993-10-01

    Translated articles cover the following topics: transient gas dynamic processes in ramjet engines; aerodynamic characteristics of delta wings with detached leading edge shock wave at hypersonic flight velocities; effect of atmospheric density gradient on aerodynamic stabilization; measurement of target radar scattering characteristics using frequency synthesized signals; assessing survivability and ensuring safety of large axial-flow compressor blades; procedure for experimentally determining transient aerodynamic forces caused by flat vane cascade; analysis of aerodynamic interaction of profile and vortex; laser machine for balancing dynamically adjusted gyros; use of heat pumps in solar heat supply systems; numerical simulation of deflagration transition to detonation in homogeneous combustible fuel mixture; and investigation of chemically nonequilibrium flow about bodies allowing for vibrational relaxation.

  1. Field free, directly heated lanthanum boride cathode

    DOEpatents

    Leung, Ka-Ngo; Moussa, D.; Wilde, S.B.

    1987-02-02

    A directly heated cylindrical lanthanum boride cathode assembly is disclosed which minimizes generation of magnetic field which would interfere with electron emission from the cathode. The cathode assembly comprises a lanthanum boride cylinder in electrical contact at one end with a central support shaft which functions as one electrode to carry current to the lanthanum boride cylinder and in electrical contact, at its opposite end with a second electrode which is coaxially position around the central support shaft so that magnetic fields generated by heater current flowing in one direction through the central support shaft are cancelled by an opposite magnetic field generated by current flowing through the lanthanum boride cylinder and the coaxial electrode in a direction opposite to the current flow in the central shaft.

  2. Central Heating Plant Coal Use Handbook. Volume 1: Technical Reference.

    DTIC Science & Technology

    1996-11-01

    variation of a dry desulfurization system simply uses dry calcium hydroxide that is injected into the flue gas stream before entry to a fabric filter...97/14, Voll 173 competitive capital and operating costs compared with conventional technology using flue gas desulfurization reduced NOx emissions...ferric iron in slag, expressed as a percentage of the total iron calculated as ferric iron FGD: Flue gas desulfurization filter: A device for

  3. Conductive heat flux in VC-1 and the thermal regime of Valles caldera, Jemez Mountains, New Mexico ( USA).

    USGS Publications Warehouse

    Sass, J.H.; Morgan, P.

    1988-01-01

    Over 5% of heat in the western USA is lost through Quaternary silicic volcanic centers, including the Valles caldera in N central New Mexico. These centers are the sites of major hydrothermal activity and upper crustal metamorphism, metasomatism, and mineralization, producing associated geothermal resources. Presents new heat flow data from Valles caldera core hole 1 (VC-1), drilled in the SW margin of the Valles caldera. Thermal conductivities were measured on 55 segments of core from VC-1, waxed and wrapped to preserve fluids. These values were combined with temperature gradient data to calculate heat flow. Above 335 m, which is probably unsaturated, heat flow is 247 + or - 16 mW m-2. Inteprets the shallow thermal gradient data and the thermal regime at VC-1 to indicate a long-lived hydrothermal (and magmatic) system in the southwestern Valles caldera that has been maintained through the generation of shallow magma bodies during the long postcollapse history of the caldera. High heat flow at the VC-1 site is interpreted to result from hot water circulating below the base of the core hole, and we attribute the lower heat flow in the unsaturated zone is attributed to hydrologic recharge. -from Authors

  4. Thermal oxidation saves $500,000, lifts capacity, upholds compliance

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

    Harley, C.G.; Nagy, A.J.; Sendecki, M.

    1985-12-01

    The age and destruction of the heat recovery system dictated the replacement of the original fume incinerator at the Congoleum Resilient Flooring Division Plant in Trenton, NJ. The original unit, installed in 1967, had a conventional air-to-oil heat recovery system. Plant personnel placed high priority on finding a replacement with a higher thermal efficiency while still maintaining environmental integrity. A proprietary software program was used to obtain values for NPV (net pressure value) for several competitive equipment systems. The NPV allows simple comparison of equipment based on data such as purchase pgsrice, cost of installation, operating costs, and maintenance costsmore » for the predicted life span of each unit. Based on NPV analysis, a regenerative thermal oxidation unit was selected. To assure expansion capability, Congoleum opted for a 30,000 scfm system. The regenerative thermal oxidation unit consists of a central combustion chamber with five lobes extending radially outward. Each lobe is packed with ceramic refractory elements (saddles) which serve as heat exchange media. The elements are retained by perforated refractory blocks on the hot combustion chamber side and by a grating on the cold side. Estimated savings from the system, about a half million dollars the first year, are expected to significantly exceed Congoleum's original estimates. About half of the total savings will result from reduced consumption of natural gas since the unit is fueled mainly by the organic material in the process exhaust. The other half of the savings has resulted from improvements in production efficiency and the recycling of waste heat from the thermal oxidizer.« less

  5. Quantitative Phosphoproteomics Reveals the Role of Protein Arginine Phosphorylation in the Bacterial Stress Response*

    PubMed Central

    Schmidt, Andreas; Trentini, Débora Broch; Spiess, Silvia; Fuhrmann, Jakob; Ammerer, Gustav; Mechtler, Karl; Clausen, Tim

    2014-01-01

    Arginine phosphorylation is an emerging protein modification implicated in the general stress response of Gram-positive bacteria. The modification is mediated by the arginine kinase McsB, which phosphorylates and inactivates the heat shock repressor CtsR. In this study, we developed a mass spectrometric approach accounting for the peculiar chemical properties of phosphoarginine. The improved methodology was used to analyze the dynamic changes in the Bacillus subtilis arginine phosphoproteome in response to different stress situations. Quantitative analysis showed that a B. subtilis mutant lacking the YwlE arginine phosphatase accumulated a strikingly large number of arginine phosphorylations (217 sites in 134 proteins), however only a minor fraction of these sites was increasingly modified during heat shock or oxidative stress. The main targets of McsB-mediated arginine phosphorylation comprise central factors of the stress response system including the CtsR and HrcA heat shock repressors, as well as major components of the protein quality control system such as the ClpCP protease and the GroEL chaperonine. These findings highlight the impact of arginine phosphorylation in orchestrating the bacterial stress response. PMID:24263382

  6. Energy supply for buildings with focus on solar power in the urban context - an interactive WebGIS implementation for citizens

    NASA Astrophysics Data System (ADS)

    Castellazzi, Bernhard; Biberacher, Markus

    2016-04-01

    Many European cities nowadays offer their citizens Web-GIS applications to access data about solar potentials for specific buildings. However, the actual benefit of such solar systems can only be investigated, if their generation is not considered singularly, but in combination with information about temporal appearance of energy demand (heat, electricity), type of primary heating system, hourly internal consumption of photovoltaic power, feed-in power and other important financial and ecological aspects. Hence, the presented application addresses citizens, who are interested in the integration of solar power in buildings and would like to have an extended view on related impacts. Based on user inputs on building parameters and energy use, as well as high spatial and temporal resolved solar data for individual roof areas, financial and ecological effects of solar thermal installations and PV are estimated. Also interactions between heat and power generation are considered in the implemented approach. The tool was developed within the Central Europe project „Cities on Power" and is being realized for the cities Torino, Warsaw, Dresden, Klagenfurt and Ravenna.

  7. Quantitative phosphoproteomics reveals the role of protein arginine phosphorylation in the bacterial stress response.

    PubMed

    Schmidt, Andreas; Trentini, Débora Broch; Spiess, Silvia; Fuhrmann, Jakob; Ammerer, Gustav; Mechtler, Karl; Clausen, Tim

    2014-02-01

    Arginine phosphorylation is an emerging protein modification implicated in the general stress response of Gram-positive bacteria. The modification is mediated by the arginine kinase McsB, which phosphorylates and inactivates the heat shock repressor CtsR. In this study, we developed a mass spectrometric approach accounting for the peculiar chemical properties of phosphoarginine. The improved methodology was used to analyze the dynamic changes in the Bacillus subtilis arginine phosphoproteome in response to different stress situations. Quantitative analysis showed that a B. subtilis mutant lacking the YwlE arginine phosphatase accumulated a strikingly large number of arginine phosphorylations (217 sites in 134 proteins), however only a minor fraction of these sites was increasingly modified during heat shock or oxidative stress. The main targets of McsB-mediated arginine phosphorylation comprise central factors of the stress response system including the CtsR and HrcA heat shock repressors, as well as major components of the protein quality control system such as the ClpCP protease and the GroEL chaperonine. These findings highlight the impact of arginine phosphorylation in orchestrating the bacterial stress response.

  8. Contrasting Heat Budget Dynamics During Two La Niña Marine Heat Wave Events Along Northwestern Australia

    NASA Astrophysics Data System (ADS)

    Xu, Jiangtao; Lowe, Ryan J.; Ivey, Gregory N.; Jones, Nicole L.; Zhang, Zhenling

    2018-02-01

    Two marine heat wave events along Western Australia (WA) during the alternate austral summer periods of 2010/2011 and 2012/2013, both linked to La Niña conditions, severely impacted marine ecosystems over more than 12° of latitude, which included the unprecedented bleaching of many coral reefs. Although these two heat waves were forced by similar large-scale climate drivers, the warming patterns differed substantially between events. The central coast of WA (south of 22°S) experienced greater warming in 2010/2011, whereas the northwestern coast of WA experienced greater warming in 2012/2013. To investigate how oceanic and atmospheric heat exchange processes drove these different spatial patterns, an analysis of the ocean heat budget was conducted by integrating remote sensing observations, in situ mooring data, and a high-resolution (˜1 km) ocean circulation model (Regional Ocean Modeling System). The results revealed substantial spatial differences in the relative contributions made by heat advection and air-sea heat exchange between the two heat wave events. During 2010/2011, anomalous warming driven by heat advection was present throughout the region but was much stronger south of 22°S where the poleward-flowing Leeuwin Current strengthens. During 2012/2013, air-sea heat exchange had a much more positive (warming) influence on sea surface temperatures (especially in the northwest), and when combined with a more positive contribution of heat advection in the north, this can explain the regional differences in warming between these two La Niña-associated marine heat wave events.

  9. Comparison of fuel-cell and diesel integrated energy systems and a conventional system for a 500-unit apartment

    NASA Technical Reports Server (NTRS)

    Simons, S. N.; Maag, W. L.

    1978-01-01

    The electrical and thermal energy utilization efficiencies of a 500 unit apartment complex are analyzed and compared for each of three energy supply systems. Two on-site integrated energy systems, one powered by diesel engines and the other by phosphoric-acid fuel cells were compared with a conventional system which uses purchased electricity and on-site boilers for heating. All fuels consumed on-site are clean, synthetic fuels (distillate fuel oil or pipeline quality gas) derived from coal. Purchased electricity was generated from coal at a central station utility. The relative energy consumption and economics of the three systems are analyzed and compared.

  10. Central sensitization as the mechanism underlying pain in joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type.

    PubMed

    Di Stefano, G; Celletti, C; Baron, R; Castori, M; Di Franco, M; La Cesa, S; Leone, C; Pepe, A; Cruccu, G; Truini, A; Camerota, F

    2016-09-01

    Patients with joint hypermobility syndrome/Ehlers-Danlos syndrome, hypermobility type (JHS/EDS-HT) commonly suffer from pain. How this hereditary connective tissue disorder causes pain remains unclear although previous studies suggested it shares similar mechanisms with neuropathic pain and fibromyalgia. In this prospective study seeking information on the mechanisms underlying pain in patients with JHS/EDS-HT, we enrolled 27 consecutive patients with this connective tissue disorder. Patients underwent a detailed clinical examination, including the neuropathic pain questionnaire DN4 and the fibromyalgia rapid screening tool. As quantitative sensory testing methods, we included thermal-pain perceptive thresholds and the wind-up ratio and recorded a standard nerve conduction study to assess non-nociceptive fibres and laser-evoked potentials, assessing nociceptive fibres. Clinical examination and diagnostic tests disclosed no somatosensory nervous system damage. Conversely, most patients suffered from widespread pain, the fibromyalgia rapid screening tool elicited positive findings, and quantitative sensory testing showed lowered cold and heat pain thresholds and an increased wind-up ratio. While the lack of somatosensory nervous system damage is incompatible with neuropathic pain as the mechanism underlying pain in JHS/EDS-HT, the lowered cold and heat pain thresholds and increased wind-up ratio imply that pain in JHS/EDS-HT might arise through central sensitization. Hence, this connective tissue disorder and fibromyalgia share similar pain mechanisms. WHAT DOES THIS STUDY ADD?: In patients with JHS/EDS-HT, the persistent nociceptive input due to joint abnormalities probably triggers central sensitization in the dorsal horn neurons and causes widespread pain. © 2016 European Pain Federation - EFIC®

  11. 10 CFR 430.62 - Submission of data.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... energy factor expressed in cycles per kilowatt-hour. (vii) Faucets, the maximum water use in gpm (L/min... seasonal energy efficiency ratio and heating seasonal performance factor. For central air conditioning heat pumps whose seasonal energy efficiency ratio and heating seasonal performance factor are based on an...

  12. ENERGY STAR Certified Non-AHRI Central Air Conditioner Equipment and Air Source Heat Pump

    EPA Pesticide Factsheets

    Certified models meet all ENERGY STAR requirements as listed in the Version 5.0 ENERGY STAR Program Requirements for Air Source Heat Pump and Central Air Conditioner Equipment that are effective as of September 15, 2015. A detailed listing of key efficiency criteria are available at http://www.energystar.gov/index.cfm?c=airsrc_heat.pr_crit_as_heat_pumps Listed products have been submitted to EPA by ENERGY STAR partners that do not participate in the AHRI certification program. EPA will continue to update this list with products that are certified by EPA-recognized certification bodies other than AHRI. The majority of ENERGY STAR products, certified by AHRI, can be found on the CEE/AHRI Verified Directory at http://www.ceedirectory.org/

  13. 10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 3 2012-01-01 2012-01-01 false Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps M Appendix M to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. M Appendix M to Subpart B of...

  14. 10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 3 2013-01-01 2013-01-01 false Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps M Appendix M to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. M Appendix M to Subpart B of...

  15. 10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 3 2014-01-01 2014-01-01 false Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps M Appendix M to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. M Appendix M to Subpart B of...

  16. 10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps M Appendix M to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. M Appendix M to Subpart B of...

  17. 10 CFR Appendix M to Subpart B of... - Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false Uniform Test Method for Measuring the Energy Consumption of Central Air Conditioners and Heat Pumps M Appendix M to Subpart B of Part 430 Energy DEPARTMENT OF ENERGY ENERGY CONSERVATION ENERGY CONSERVATION PROGRAM FOR CONSUMER PRODUCTS Test Procedures Pt. 430, Subpt. B, App. M Appendix M to Subpart B of...

  18. Compliance Testing of Grissom AFB Central Heating Plant Coal-Fired Boilers 3 and 5, Grissom AFB, Indiana

    DTIC Science & Technology

    1988-06-01

    common breeching and can be routed to the wet-scrubber or to a bypass stack. The scrubber is a double-alkali flue - gas desulfurization system using soda...Illustrations Figure Title Page 1 View of Scrubber and Bypass Stacks 3 2 Scrubber Stacks 4 3 Bypass Stack 5 4 Flue Gas Flow Diagram 6 5 ORSAT Sampling...of gases and to provide a positive static pressure at flue gas exhaust discharge points. The ash system pneumatically removes ash from bottom-ash

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

    Turner, D. D.; Wulfmeyer, V.; Behrendt, A.

    On 21 August 2017, a solar eclipse occurred over the continental United States resulting in a rapid reduction and subsequent increase of solar radiation over a large region of the country. The eclipse’s effect on the land-atmosphere system is documented in unprecedented detail using a unique array of sensors deployed at three sites in north-central Oklahoma. The observations showed that turbulent fluxes of heat and momentum at the surface responded quickly to the change in solar radiation. The decrease in the sensible heat flux resulted in a decrease in the air temperature below 200 m, and a large decrease inmore » turbulent motions throughout the boundary layer. Furthermore, the turbulent mixing in the boundary layer lagged behind the change in the surface fluxes, and this lag depended on the height above the surface. The turbulent motions increased and the convective boundary layer was reestablished as the sensible heat flux recovered.« less

  20. Heat regulation: homeostasis of central temperature in man.

    PubMed

    Benzinger, T H

    1969-10-01

    Focus is on the concept of the quantitative thermostat or setpoint as it evolved experimentally, not theoretically, from measurements of central temperature at the tympanic membrane and from measurements of physiological responses by human gradient layer calorimetry and continuous analysis of oxygen consumption. Heat-flow responses as they relate to stimuli by which they are evoked -- peripheral or central temperatures at thermoreceptive sites -- and discussed, and individual systems of reflex action are described. These systems are then correlated with what is known of their tangible components -- sensory receptors, effector organs, nervous centers, and afferent or efferent nervous pathways -- classically derived from anatomical studies, lesion experiments, recording of action currents, or electrical or thermal stimulation of pertinent structures. Such as correlation is a crucial test, and when the results are consistent, they provide independent, mutual confirmation via the 2 approaches. Doubts are then removed that lesions or interferences, which are unavoidable with most neurophysiological methods, may have produced artifacts. Conversely, calorimetry allows one to observe and analyze thermoregulation in process in a human subject without disturbing normal structures or functions other than by the stresses to which the body is made to respond. Prior to a description of experimental findings, the essential methods are reviewed. With the methods of gradient layer calorimetry, tympanic (eardrum) thermonetry, and indirect calorimetry, thermoregulatory responses -- by chemical overproduction of metabolic heat -- were observed in transient states as a result of a stimulus of cold impinging on peripheral neurons or warm-inhibition removed from central structures. With tympanic thermometry permitting for the 1st time om humans the continuous recording of central thermal stimulation, and with gradient calorimetry permitting the continuous recording (with insignificant inertial distortion) of the sweating responses in precisely controlled environments of a large variety and under conditions where complete evaporation of sweat is ensured by strong but smooth air convection, a new study of physical thermoregulation was initiated in 1958. The experimental results did not support the expection that sweating would follow the average temperature of the skin in the classical tradition, with skin warm-receptors as the hypothetical origin of exciting warm-impulses and cenral temperature as a participant prescribing the action of the "thermoregulator" in some as yet undetermined, additive, manner. Vasomotor mechanisms to human thermoregulation can be assessed in quantitative manner only by whole-body calorimetry. Mechanisms of thermal homeostasis also considered include hormonal regulation, transmitter substances, conscious sensation of warmth and coordinations of behavioral and autonomic mechanisms, setpoint and its variations, and fever.

  1. Denver airport pumping systems achieve optimal [Delta] T's

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

    Mannion, G.F.; Krist, G.D.

    1994-07-01

    This article describes how the pumping and generating systems at the new Denver Airport operate efficiently with the user loops in the buildings producing design temperature rise at all load levels. Fifteen miles east of Denver's Stapleton International Airport lies the newly completed Denver International Airport (DIA)--the world's largest and most high-tech airport. Besides being one of the largest construction projects in the works, it has many of the latest technical innovations available. Of particular interest to the HVAC industry is the design of the heating and cooling water systems. These systems provide environmental cooling and heating water to themore » three concourses, the airport office building, and the main terminal. The mechanical engineers for the project were all from the Denver area. The central plant design was the work of Behrent Engineering Co.; the three concourses were designed by Swanson-Rink Associates; and the main terminal and administrative office building were designed by Abeyta Engineering Consultants. The overall system concept was developed during the initial design phase by engineers from these firms, members of the DIA staff, and application engineers from several manufacturers.« less

  2. On the possibility of generation of cold and additional electric energy at thermal power stations

    NASA Astrophysics Data System (ADS)

    Klimenko, A. V.; Agababov, V. S.; Borisova, P. N.

    2017-06-01

    A layout of a cogeneration plant for centralized supply of the users with electricity and cold (ECCG plant) is presented. The basic components of the plant are an expander-generator unit (EGU) and a vapor-compression thermotransformer (VCTT). At the natural-gas-pressure-reducing stations, viz., gas-distribution stations and gas-control units, the plant is connected in parallel to a throttler and replaces the latter completely or partially. The plant operates using only the energy of the natural gas flow without burning the gas; therefore, it can be classified as a fuelless installation. The authors compare the thermodynamic efficiencies of a centralized cold supply system based on the proposed plant integrated into the thermal power station scheme and a decentralized cold supply system in which the cold is generated by electrically driven vapor-compression thermotransformers installed on the user's premises. To perform comparative analysis, the exergy efficiency was taken as the criterion since in one of the systems under investigation the electricity and the cold are generated, which are energies of different kinds. It is shown that the thermodynamic efficiency of the power supply using the proposed plant proves to be higher within the entire range of the parameters under consideration. The article presents the results of investigating the impact of the gas heating temperature upstream from the expander on the electric power of the plant, its total cooling capacity, and the cooling capacities of the heat exchangers installed downstream from the EGU and the evaporator of the VCTT. The results of calculations are discussed that show that the cold generated at the gas-control unit of a powerful thermal power station can be used for the centralized supply of the cold to the ventilation and conditioning systems of both the buildings of the power station and the neighboring dwelling houses, schools, and public facilities during the summer season.

  3. Wood energy for residential heating in Alaska: current conditions, attitudes, and expected use

    Treesearch

    David L. Nicholls; Allen M. Brackley; Valerie Barber

    2010-01-01

    This study considered three aspects of residential wood energy use in Alaska: current conditions and fuel consumption, knowledge and attitudes, and future use and conditions. We found that heating oil was the primary fuel for home heating in southeast and interior Alaska, whereas natural gas was used most often in south-central Alaska (Anchorage). Firewood heating...

  4. Mechanisms of orthostatic intolerance during heat stress

    PubMed Central

    Schlader, Zachary J.; Wilson, Thad E.; Crandall, Craig G.

    2017-01-01

    Heat stress profoundly and unanimously reduces orthostatic tolerance. This review aims to provide an overview of the numerous and multifactorial mechanisms by which this occurs in humans. Potential causal factors include changes in arterial and venous vascular resistance and blood distribution, and the modulation of cardiac output, all of which contribute to the inability to maintain cerebral perfusion during heat and orthostatic stress. A number of countermeasures have been established to improve orthostatic tolerance during heat stress, which alleviate heat stress induced central hypovolemia (e.g., volume expansion) and/or increase peripheral vascular resistance (e.g., skin cooling). Unfortunately, these countermeasures can often be cumbersome to use with populations prone to syncopal episodes. Identifying the mechanisms of inter-individual differences in orthostatic intolerance during heat stress has proven elusive, but could provide greater insights into the development of novel and personalized countermeasures for maintaining or improving orthostatic tolerance during heat stress. This development will be especially impactful in occuational settings and clinical situations that present with orthostatic intolerance and/or central hypovolemia. Such investigations should be considered of vital importance given the impending increased incidence of heat events, and associated cardiovascular challenges that are predicted to occur with the ensuing changes in climate. PMID:26723547

  5. Future heat waves and surface ozone

    NASA Astrophysics Data System (ADS)

    Meehl, Gerald A.; Tebaldi, Claudia; Tilmes, Simone; Lamarque, Jean-Francois; Bates, Susan; Pendergrass, Angeline; Lombardozzi, Danica

    2018-06-01

    A global Earth system model is used to study the relationship between heat waves and surface ozone levels over land areas around the world that could experience either large decreases or little change in future ozone precursor emissions. The model is driven by emissions of greenhouse gases and ozone precursors from a medium-high emission scenario (Representative Concentration Pathway 6.0–RCP6.0) and is compared to an experiment with anthropogenic ozone precursor emissions fixed at 2005 levels. With ongoing increases in greenhouse gases and corresponding increases in average temperature in both experiments, heat waves are projected to become more intense over most global land areas (greater maximum temperatures during heat waves). However, surface ozone concentrations on future heat wave days decrease proportionately more than on non-heat wave days in areas where ozone precursors are prescribed to decrease in RCP6.0 (e.g. most of North America and Europe), while surface ozone concentrations in heat waves increase in areas where ozone precursors either increase or have little change (e.g. central Asia, the Mideast, northern Africa). In the stabilized ozone precursor experiment, surface ozone concentrations increase on future heat wave days compared to non-heat wave days in most regions except in areas where there is ozone suppression that contributes to decreases in ozone in future heat waves. This is likely associated with effects of changes in isoprene emissions at high temperatures (e.g. west coast and southeastern North America, eastern Europe).

  6. Vertical Profiles of Latent Heat Release over the Global Tropics using TRMM rainfall products from December 1997 to November 2001

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.

    2002-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2001. Rainfall, latent heating and radar reflectivity structures between El Nino (DE 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs. west Pacific, Africa vs. S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in strtaiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMEX), Brazil in 1999 (TRMM-LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model.

  7. Vertical Profiles of Latent Heat Release Over the Global Tropics using TRMM Rainfall Products from December 1997 to November 2001

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Simpson, J.; Meneghini, R.; Halverson, J.; Johnson, R.; Adler, R.; Starr, David (Technical Monitor)

    2002-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in stratiform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMEX), Brazil in 1999 (TRMM-LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model.

  8. Vertical Profiles of Latent Heat Release over the Global Tropics Using TRMM Rainfall Products from December 1997 to November 2002

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.

    2003-01-01

    NASA Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) derived rainfall information will be used to estimate the four-dimensional structure of global monthly latent heating and rainfall profiles over the global tropics from December 1997 to November 2000. Rainfall, latent heating and radar reflectivity structures between El Nino (DJF 1997-98) and La Nina (DJF 1998-99) will be examined and compared. The seasonal variation of heating over various geographic locations (i.e., oceanic vs continental, Indian ocean vs west Pacific, Africa vs S. America) will also be analyzed. In addition, the relationship between rainfall, latent heating (maximum heating level), radar reflectivity and SST is examined and will be presented in the meeting. The impact of random error and bias in straitform percentage estimates from PR on latent heating profiles is studied and will also be presented in the meeting. The Goddard Cumulus Ensemble Model is being used to simulate various mesoscale convective systems that developed in different geographic locations. Specifically, the model estimated rainfall, radar reflectivity and latent heating profiles will be compared to observational data collected from TRMM field campaigns over the South China Sea in 1998 (SCSMXX), Brazil in 1999 (TRMM- LBA), and the central Pacific in 1999 (KWAJEX). Sounding diagnosed heating budgets and radar reflectivity from these experiments can provide the means to validate (heating product) as well as improve the GCE model.

  9. Einstein-Podolsky-Rosen paradox implies a minimum achievable temperature

    NASA Astrophysics Data System (ADS)

    Rogers, David M.

    2017-01-01

    This work examines the thermodynamic consequences of the repeated partial projection model for coupling a quantum system to an arbitrary series of environments under feedback control. This paper provides observational definitions of heat and work that can be realized in current laboratory setups. In contrast to other definitions, it uses only properties of the environment and the measurement outcomes, avoiding references to the "measurement" of the central system's state in any basis. These definitions are consistent with the usual laws of thermodynamics at all temperatures, while never requiring complete projective measurement of the entire system. It is shown that the back action of measurement must be counted as work rather than heat to satisfy the second law. Comparisons are made to quantum jump (unravelling) and transition-probability based definitions, many of which appear as particular limits of the present model. These limits show that our total entropy production is a lower bound on traditional definitions of heat that trace out the measurement device. Examining the master equation approximation to the process at finite measurement rates, we show that most interactions with the environment make the system unable to reach absolute zero. We give an explicit formula for the minimum temperature achievable in repeatedly measured quantum systems. The phenomenon of minimum temperature offers an explanation of recent experiments aimed at testing fluctuation theorems in the quantum realm and places a fundamental purity limit on quantum computers.

  10. Geothermal Heat Flux: Linking Deep Earth's Interior and the Dynamics of Large-Scale Ice Sheets

    NASA Astrophysics Data System (ADS)

    Rogozhina, Irina; Vaughan, Alan

    2014-05-01

    Regions covered by continental-scale ice sheets have the highest degree of uncertainty in composition and structure of the crust and lithospheric mantle, compounded by the poorest coverage on Earth of direct heat flow measurements. In addition to challenging conditions that make direct measurements and geological survey difficult Greenland and Antarctica are known to be geologically complex. Antarctica in particular is marked by two lithospherically distinct zones. In contrast to young and thin lithosphere of West Antarctica, East Antarctica is a collage of thick Precambrian fragments of Gondwana and earlier supercontinents. However, recent observations and modeling studies have detected large systems of subglacial lakes extending beneath much of the East Antarctic ice sheet base that have been linked to anomalously elevated heat flow. Outcrop samples from the rift margin with Australia (Prydz Bay) have revealed highly radiogenic Cambrian granite intrusives that are implicated in regional increase of crustal heat flux by a factor of two to three compared to the estimated continental background. Taken together, these indicate high variability of heat flow and properties of rocks across Antarctica. Similar conclusions have been made based on direct measurements and observations of the Greenland ice sheet. Airborne ice-penetrating radar and deep ice core projects show very high rates of basal melt for parts of the ice sheet in northern and central Greenland that have been explained by abnormally high heat flux. Archaean in age, the Greenland lithosphere was significantly reworked during the Early Proterozoic. In this region, the interpretation of independent geophysical data is complicated by Proterozoic and Phanerozoic collision zones, compounded by strong thermochemical effects of rifting along the western and eastern continental margins between 80 and 25 million years ago. In addition, high variability of heat flow and thermal lithosphere structure in central Greenland results from the remanent effects of an Early Cenozoic passage of the lithosphere above the Iceland mantle plume that is implicated in strong thermochemical erosion of the lithosphere and significant long-term effects on the present-day subglacial heat flow pattern and thermodynamic state of the Greenland ice sheet. These observations and our modeling results (Petrunin et al., 2013) show that the present-day thermal state of Greenland and Antarctic lithosphere cannot be well understood without taking into account a long-term tectonic history of these regions. The goal of the IceGeoHeat project is to combine existing independent geophysical data and innovative modeling approaches to comprehensively study the evolution and present state of the lithosphere in Greenland and Antarctica, and assess the role of geothermal heat flux in shaping the present-day ice sheet dynamics. This requires multiple collaborations involving experts across a range of disciplines. The project builds on the IceGeoHeat initiative formed in April 2012 and now including researchers from ten countries in the main core (MC) with expertise in numerical modeling and data assessment in geodynamics, geology, geothermics, cryosphere and (paleo-)climate. Petrunin, A., Rogozhina, I., Vaughan, A. P. M., Kukkonen, I. T., Kaban, M., Koulakov, I., Thomas, M. (2013): Heat flux variations beneath central Greenland's ice due to anomalously thin lithosphere. - Nature Geoscience, 6, 746-750.

  11. Unified picture of strong-coupling stochastic thermodynamics and time reversals

    NASA Astrophysics Data System (ADS)

    Aurell, Erik

    2018-04-01

    Strong-coupling statistical thermodynamics is formulated as the Hamiltonian dynamics of an observed system interacting with another unobserved system (a bath). It is shown that the entropy production functional of stochastic thermodynamics, defined as the log ratio of forward and backward system path probabilities, is in a one-to-one relation with the log ratios of the joint initial conditions of the system and the bath. A version of strong-coupling statistical thermodynamics where the system-bath interaction vanishes at the beginning and at the end of a process is, as is also weak-coupling stochastic thermodynamics, related to the bath initially in equilibrium by itself. The heat is then the change of bath energy over the process, and it is discussed when this heat is a functional of the system history alone. The version of strong-coupling statistical thermodynamics introduced by Seifert and Jarzynski is related to the bath initially in conditional equilibrium with respect to the system. This leads to heat as another functional of the system history which needs to be determined by thermodynamic integration. The log ratio of forward and backward system path probabilities in a stochastic process is finally related to log ratios of the initial conditions of a combined system and bath. It is shown that the entropy production formulas of stochastic processes under a general class of time reversals are given by the differences of bath energies in a larger underlying Hamiltonian system. The paper highlights the centrality of time reversal in stochastic thermodynamics, also in the case of strong coupling.

  12. Dysfunction of Iron Metabolism and Iron-Regulatory Proteins in the Rat Hippocampus After Heat Stroke.

    PubMed

    Liu, Jing; Wan, Shengming; Zhang, Yun; Zhang, Shu; Zhang, Hongying; Wu, Shiwen

    2018-05-11

    Heat stroke, the most serious type of heat illness, refers to the presence of hyperthermia (core temperature >40°C), accompanied by central nervous system dysfunction. The hippocampus is a particularly vulnerable region in the early stage of heat stroke. Increasing evidence suggests that dysregulation of brain iron metabolism is involved in many neurodegenerative diseases. However, whether heat stroke causes dysfunction of iron metabolism, as well as iron-regulatory proteins, in the hippocampus remains unknown. The present study was conducted to explore the effects on spatial learning and memory, as well as iron content, ferroportin 1 (Fpn1), and hepcidin expression in the hippocampus after heat stroke in rats. Compared with the Sham group, learning ability and memory declined in rats after heat stroke. Iron concentration was significantly increased in the hippocampus. Expression of Fpn1 protein significantly decreased in the hippocampus, while expression of hepcidin increased. Interestingly, Fpn1 mRNA expression in the hippocampus increased. Our data thereby indicate that heat stroke can decrease learning ability and memory in rats. The mechanism may be related to changes of iron levels, as well as Fpn1 and hepcidin expression, in the hippocampus. Furthermore, hepcidin may rapidly decrease cellular Fpn1 protein levels, even under conditions of iron loading, indicating that hepcidin is a more dominant regulator of Fpn1 than is iron.

  13. A GIS approach to urban heat island research: The case of Huntsville, Alabama

    NASA Technical Reports Server (NTRS)

    Lo, Chor Pong

    1994-01-01

    The urban heat island represents a case of inadvertent human modification of climate in an urban environment. Urbanization changes the nature of the surface and atmospheric properties of a region. As a result, radiation balance in the urban areas is altered and sensible heat is added to the point that urban areas are warmer than surrounding rural areas. At the boundary between the rural and urban area, a sharp rise in temperature occurs, culminating to a peak temperature at the central business district of the city, hence the name 'urban heat island'. The extent and intensity of the urban heat island are a function of population size, land use, and topography. Because the urban heat island exhibits spatial variations of temperatures, the use of Geographic Information System (GIS) is appropriate. The research on the urban heat island focuses on the acquisition of 15 bands of visible and thermal infrared data (ranging from 0.45 to 12.2 microns) from an aerial platform using NASA's ATLAS (Airborne Thermal/Visible Land Application Sensor) over Huntsville, Alabama. The research reported in this paper is an analysis of the impact of population, land use, and topography on the shape of the urban heat island that could be developed in Huntsville using the GIS approach. The outcome of this analysis can then be verified using the acquired remotely sensed data.

  14. A device for microwave sintering large ceramic articles

    DOEpatents

    Kimrey, H.D. Jr.

    1987-07-24

    A microwave sintering system is provided for uniform sintering of large and/or irregular shapes ceramic articles at microwave frequencies of at least 28 GHz in the hundreds of kilowatts power range in an untuned cavity. A 28 GHz, 200 kw gyrotron with variable power output is used as the microwave source connected to an untuned microwave cavity formed of an electrically conductive housing. The part to be sintered is placed in the cavity and supported on a removable high temperature table in a central location within the cavity. The part is surrounded by a microwave transparent bulk insulating material to reduce thermal heat loss at the part surfaces and maintain more uniform temperature. The cavity may be operated at a high vacuum to aid in preventing arcing. The system allows controlled increased heating rates of greater than 200/degree/C/min to provide rapid heating of a ceramic part to a selected sintering temperature where it is maintained by regulating the microwave power applied to the part. As a result of rapid heating, the extent on non-isothermal processes such as segregation of impurities to the grain boundaries are minimized and exaggerated grain growth is reduced, thereby strengthening the mechanical properties of the ceramic part being sintered. 1 fig.

  15. Conductor analysis of the ITER FEAT poloidal field coils during a plasma scenario

    NASA Astrophysics Data System (ADS)

    Nicollet, S.; Hertout, P.; Duchateau, J. L.; Bleyer, A.; Bessette, D.

    2002-05-01

    In the framework of the ITER (International Thermonuclear Experimental Reactor) FEAT (Fusion Energy Advanced Tokamak) project, a fully superconducting PF (Poloidal Field) system has been designed in detail. The Central Solenoid and the 6 equilibrium coils constituting the PF system provide the magnetic fields which develop, shape and control the 15 MA plasma during the 1800 s of a typical plasma scenario. The 6 PF coils will be wound two-in-hand from a 45 kA niobium-titanium CICC (Cable-In-Conduit-Conductor). These coils will experience severe heat loads specially during the 400 s of the plasma burn: nuclear heating due to the 400 MW of fusion power, thermal radiation and AC losses (30 to 300 kJ). The AC losses along the PF coil pancakes are deduced from accurate magnetic field computations performed with a 3D magnetostatic code, TRAPS. The nuclear heating and the thermal radiation are assumed to be uniform over a given face of the PF coils. These heat loads are used as input to perform the thermal and hydraulic analysis with a finite element code, GANDALF. The temperature increases (0.1 to 0.4 K) are computed, the margins and performances of the conductor are evaluated.

  16. Turbulent heating in galaxy clusters brightest in X-rays.

    PubMed

    Zhuravleva, I; Churazov, E; Schekochihin, A A; Allen, S W; Arévalo, P; Fabian, A C; Forman, W R; Sanders, J S; Simionescu, A; Sunyaev, R; Vikhlinin, A; Werner, N

    2014-11-06

    The hot (10(7) to 10(8) kelvin), X-ray-emitting intracluster medium (ICM) is the dominant baryonic constituent of clusters of galaxies. In the cores of many clusters, radiative energy losses from the ICM occur on timescales much shorter than the age of the system. Unchecked, this cooling would lead to massive accumulations of cold gas and vigorous star formation, in contradiction to observations. Various sources of energy capable of compensating for these cooling losses have been proposed, the most promising being heating by the supermassive black holes in the central galaxies, through inflation of bubbles of relativistic plasma. Regardless of the original source of energy, the question of how this energy is transferred to the ICM remains open. Here we present a plausible solution to this question based on deep X-ray data and a new data analysis method that enable us to evaluate directly the ICM heating rate from the dissipation of turbulence. We find that turbulent heating is sufficient to offset radiative cooling and indeed appears to balance it locally at each radius-it may therefore be the key element in resolving the gas cooling problem in cluster cores and, more universally, in the atmospheres of X-ray-emitting, gas-rich systems on scales from galaxy clusters to groups and elliptical galaxies.

  17. Seasonal and Interannual Variations of Sea Ice Mass Balance From the Central Arctic to the Greenland Sea

    NASA Astrophysics Data System (ADS)

    Lei, Ruibo; Cheng, Bin; Heil, Petra; Vihma, Timo; Wang, Jia; Ji, Qing; Zhang, Zhanhai

    2018-04-01

    The seasonal evolution of sea ice mass balance between the Central Arctic and Fram Strait, as well as the underlying driving forces, remain largely unknown because of a lack of observations. In this study, two and three buoys were deployed in the Central Arctic during the summers of 2010 and 2012, respectively. It was established that basal ice growth commenced between mid-October and early December. Annual basal ice growth, ranging from 0.21 to 1.14 m, was determined mainly by initial ice thickness, air temperature, and oceanic heat flux during winter. An analytic thermodynamic model indicated that climate warming reduces the winter growth rate of thin ice more than for thick ice because of the weak thermal inertia of the former. Oceanic heat flux during the freezing season was 2-4 W m-2, which accounted for 18-31% of the basal ice energy balance. We identified two mechanisms that modified the oceanic heat flux, i.e., solar energy absorbed by the upper ocean during summer, and interaction with warm waters south of Fram Strait; the latter resulted in basal ice melt, even in winter. In summer 2010, ice loss in the Central Arctic was considerable, which led to increased oceanic heat flux into winter and delayed ice growth. The Transpolar Drift Stream was relatively weak in summer 2013. This reduced sea ice advection out of the Arctic Ocean, and it restrained ice melt because of the cool atmospheric conditions, weakened albedo feedback, and relatively small oceanic heat flux in the north.

  18. Handling Hot Water, With a Payoff

    ERIC Educational Resources Information Center

    Stewart, Ronald; Mathur, S. P.

    1970-01-01

    Discusses methods of utilizing waste heat from the increasing number of power stations. Possible uses include agri- and mariculture, centralized urban and industrial heating, and deicing of airports and marine facilities. (AL)

  19. Realizing "2001: A Space Odyssey": Piloted Spherical Torus Nuclear Fusion Propulsion

    NASA Technical Reports Server (NTRS)

    Williams, Craig H.; Dudzinski, Leonard A.; Borowski, Stanley K.; Juhasz, Albert J.

    2005-01-01

    A conceptual vehicle design enabling fast, piloted outer solar system travel was created predicated on a small aspect ratio spherical torus nuclear fusion reactor. The initial requirements were satisfied by the vehicle concept, which could deliver a 172 mt crew payload from Earth to Jupiter rendezvous in 118 days, with an initial mass in low Earth orbit of 1,690 mt. Engineering conceptual design, analysis, and assessment was performed on all major systems including artificial gravity payload, central truss, nuclear fusion reactor, power conversion, magnetic nozzle, fast wave plasma heating, tankage, fuel pellet injector, startup/re-start fission reactor and battery bank, refrigeration, reaction control, communications, mission design, and space operations. Detailed fusion reactor design included analysis of plasma characteristics, power balance/utilization, first wall, toroidal field coils, heat transfer, and neutron/x-ray radiation. Technical comparisons are made between the vehicle concept and the interplanetary spacecraft depicted in the motion picture 2001: A Space Odyssey.

  20. Engineering Biomaterial Properties for Central Nervous System Applications

    NASA Astrophysics Data System (ADS)

    Rivet, Christopher John

    Biomaterials offer unique properties that are intrinsic to the chemistry of the material itself or occur as a result of the fabrication process; iron oxide nanoparticles are superparamagnetic, which enables controlled heating in the presence of an alternating magnetic field, and a hydrogel and electrospun fiber hybrid material provides minimally invasive placement of a fibrous, artificial extracellular matrix for tissue regeneration. Utilization of these unique properties towards central nervous system disease and dysfunction requires a thorough definition of the properties in concert with full biological assessment. This enables development of material-specific features to elicit unique cellular responses. Iron oxide nanoparticles are first investigated for material-dependent, cortical neuron cytotoxicity in vitro and subsequently evaluated for alternating magnetic field stimulation induced hyperthermia, emulating the clinical application for enhanced chemotherapy efficacy in glioblastoma treatment. A hydrogel and electrospun fiber hybrid material is first applied to a rat brain to evaluate biomaterial interface astrocyte accumulation as a function of hybrid material composition. The hybrid material is then utilized towards increasing functional engraftment of dopaminergic progenitor neural stem cells in a mouse model of Parkinson's disease. Taken together, these two scenarios display the role of material property characterization in development of biomaterial strategies for central nervous system repair and regeneration.

  1. Pioneering Heat Pump Project

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

    Aschliman, Dave; Lubbehusen, Mike

    2015-06-30

    This project was initiated at a time when ground coupled heat pump systems in this region were limited in size and quantity. There were economic pressures with costs for natural gas and electric utilities that had many organizations considering ground coupled heat pumps; The research has added to the understanding of how ground temperatures fluctuate seasonally and how this affects the performance and operation of the heat pumps. This was done by using a series of temperature sensors buried within the middle of one of the vertical bore fields with sensors located at various depths below grade. Trending of themore » data showed that there is a lag in ground temperature with respect to air temperatures in the shoulder months, however as full cooling and heating season arrives, the heat rejection and heat extraction from the ground has a significant effect on the ground temps; Additionally it is better understood that while a large community geothermal bore field serving multiple buildings does provide a convenient central plant to use, it introduces complexity of not being able to easily model and predict how each building will contribute to the loads in real time. Additional controllers and programming were added to provide more insight into this real time load profile and allow for intelligent shedding of load via a dry cooler during cool nights in lieu of rejecting to the ground loop. This serves as a means to ‘condition’ the ground loop and mitigate thermal creep of the field, as is typically observed; and It has been observed when compared to traditional heating and cooling equipment, there is still a cost premium to use ground source heat pumps that is driven mostly by the cost for vertical bore holes. Horizontal loop systems are less costly to install, but do not perform as well in this climate zone for heating mode« less

  2. Preliminary design of a solar central receiver for site-specific repowering application (Saguaro Power Plant). Volume II. Preliminary design. Final report, October 1982-September 1983

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

    Weber, E.R.

    1983-09-01

    The solar central receiver technology, site, and specific unit for repowering were selected in prior analyses and studies. The objectives of this preliminary design study were to: develop a solar central receiver repowering design for Saguaro that (1) has potential to be economically competitive with fossil fueled plants in near and long term applications, (2) has the greatest chance for completion without further government funding, (3) will further define technical and economic feasibility of a 66 MWe gross size plant that is adequate to meet the requirements for utility and industrial process heat applications, (4) can potentially be constructed andmore » operated within the next five years, and (5) incorporates solar central receiver technology and represents state-of-the-art development. This volume on the preliminary design includes the following sections: executive summary; introduction; changes from advanced conceptual design; preliminary design; system characteristics; economic analysis; and development plan.« less

  3. Multiphase environment of compact galactic nuclei: the role of the nuclear star cluster

    NASA Astrophysics Data System (ADS)

    Różańska, A.; Kunneriath, D.; Czerny, B.; Adhikari, T. P.; Karas, V.

    2017-01-01

    We study the conditions for the onset of thermal instability in the innermost regions of compact galactic nuclei, where the properties of the interstellar environment are governed by the interplay of quasi-spherical accretion on to a supermassive black hole (SMBH) and the heating/cooling processes of gas in a dense nuclear star cluster (NSC). Stellar winds are the source of material for radiatively inefficient (quasi-spherical, non-magnetized) inflow/outflow on to the central SMBH, where a stagnation point develops within the Bondi-type accretion. We study the local thermal equilibrium to determine the parameter space that allows cold and hot phases in mutual contact to co-exist. We include the effects of mechanical heating by stellar winds and radiative cooling/heating by the ambient field of the dense star cluster. We consider two examples: the NSC in the Milky Way central region (including the gaseous mini-spiral of Sgr A*), and the ultracompact dwarf galaxy M60-UCD1. We find that the two systems behave in different ways because they are placed in different areas of parameter space in the instability diagram: gas temperature versus dynamical ionization parameter. In the case of Sgr A*, stellar heating prevents the spontaneous formation of cold clouds. The plasma from stellar winds joins the hot X-ray emitting phase and forms an outflow. In M60-UCD1, our model predicts spontaneous formation of cold clouds in the inner part of the galaxy. These cold clouds may survive since the cooling time-scale is shorter than the inflow/outflow time-scale.

  4. Polar Biomedical Research: An Assessment. Appendix. Polar Medicine - A Literature Review.

    DTIC Science & Technology

    1982-10-01

    hypoglycemia of any cause , function of the central nervous system thermoregulatory centers is disturbed because of low cerebrospinal fluid glucose...insulin required to correct the hyperglycemia may cause profound hypoglycemia as the patient is warmed. For this reason hyperglycemia should be treated...summarized.151,163-16 5 As tissue cools, several mechanisms decrease tissue perfusion and thereby reduce heat 1o8..166 Cold causes directl6 7-169 and

  5. 8. PHOTOCOPY, HEATING DRAWING FOR ADMINISTRATION BUILDING. NIKE Missile ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    8. PHOTOCOPY, HEATING DRAWING FOR ADMINISTRATION BUILDING. - NIKE Missile Base SL-40, Administration Building, East central portion of base, southeast of Mess Hall, northeast of HIPAR Equipment Building, Hecker, Monroe County, IL

  6. Mixed Layer Temperature Budget for the Northward Propagating Summer Monsoon Intraseasonal Oscillation (MISO) in the Central Bay of Bengal

    NASA Astrophysics Data System (ADS)

    Girishkumar, M. S.; Joseph, J.; Thangaprakash, V. P.; Pottapinjara, V.; McPhaden, M. J.

    2017-11-01

    Composite analyses of mixed layer temperature (MLT) budget terms from near-surface meteorological and oceanic observations in the central Bay of Bengal are utilized to evaluate the modulation of air-sea interactions and MLT processes in response to the summer monsoon intraseasonal oscillation (MISO). For this purpose, we use moored buoy data at 15°N, 12°N, and 8°N along 90°E together with TropFlux meteorological parameters and the Ocean Surface Current Analyses Real-time (OSCAR) current product. Our analysis shows a strong cooling tendency in MLT with maximum amplitude in the central and northern BoB during the northward propagation of enhanced convective activity associated with the active phase of the MISO; conversely, warming occurs during the suppressed phase of the MISO. The surface mixed layer is generally heated during convectively inactive phases of the MISO primarily due to increased net surface heat flux into the ocean. During convectively active MISO phases, the surface mixed layer is cooled by the combined influence of net surface heat loss to the atmosphere and entrainment cooling at the base of mixed layer. The variability of net surface heat flux is primarily due to modulation of latent heat flux and shortwave radiation. Shortwave is mostly controlled by an enhancement or reduction of cloudiness during the active and inactive MISO phases and latent heat flux is mostly controlled by variations in air-sea humidity difference.

  7. Slow Temporal Summation of Pain for Assessment of Central Pain Sensitivity and Clinical Pain of Fibromyalgia Patients

    PubMed Central

    Staud, Roland; Weyl, Elizabeth E.; Riley, Joseph L.; Fillingim, Roger B.

    2014-01-01

    Background In healthy individuals slow temporal summation of pain or wind-up (WU) can be evoked by repetitive heat-pulses at frequencies of ≥.33 Hz. Previous WU studies have used various stimulus frequencies and intensities to characterize central sensitization of human subjects including fibromyalgia (FM) patients. However, many trials demonstrated considerable WU-variability including zero WU or even wind-down (WD) at stimulus intensities sufficient for activating C-nociceptors. Additionally, few WU-protocols have controlled for contributions of individual pain sensitivity to WU-magnitude, which is critical for WU-comparisons. We hypothesized that integration of 3 different WU-trains into a single WU-response function (WU-RF) would not only control for individuals’ pain sensitivity but also better characterize their central pain responding including WU and WD. Methods 33 normal controls (NC) and 38 FM patients participated in a study of heat-WU. We systematically varied stimulus intensities of.4 Hz heat-pulse trains applied to the hands. Pain summation was calculated as difference scores of 1st and 5th heat-pulse ratings. WU-difference (WU-Δ) scores related to 3 heat-pulse trains (44°C, 46°C, 48°C) were integrated into WU-response functions whose slopes were used to assess group differences in central pain sensitivity. WU-aftersensations (WU-AS) at 15 s and 30 s were used to predict clinical FM pain intensity. Results WU-Δ scores linearly accelerated with increasing stimulus intensity (p<.001) in both groups of subjects (FM>NC) from WD to WU. Slope of WU-RF, which is representative of central pain sensitivity, was significantly steeper in FM patients than NC (p<.003). WU-AS predicted clinical FM pain intensity (Pearson’s r = .4; p<.04). Conclusions Compared to single WU series, WU-RFs integrate individuals’ pain sensitivity as well as WU and WD. Slope of WU-RFs was significantly different between FM patients and NC. Therefore WU-RF may be useful for assessing central sensitization of chronic pain patients in research and clinical practice. PMID:24558475

  8. Temperature and blood flow distribution in the human leg during passive heat stress.

    PubMed

    Chiesa, Scott T; Trangmar, Steven J; González-Alonso, José

    2016-05-01

    The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. Copyright © 2016 the American Physiological Society.

  9. Temperature and blood flow distribution in the human leg during passive heat stress

    PubMed Central

    Chiesa, Scott T.; Trangmar, Steven J.

    2016-01-01

    The influence of temperature on the hemodynamic adjustments to direct passive heat stress within the leg's major arterial and venous vessels and compartments remains unclear. Fifteen healthy young males were tested during exposure to either passive whole body heat stress to levels approaching thermal tolerance [core temperature (Tc) + 2°C; study 1; n = 8] or single leg heat stress (Tc + 0°C; study 2; n = 7). Whole body heat stress increased perfusion and decreased oscillatory shear index in relation to the rise in leg temperature (Tleg) in all three major arteries supplying the leg, plateauing in the common and superficial femoral arteries before reaching severe heat stress levels. Isolated leg heat stress increased arterial blood flows and shear patterns to a level similar to that obtained during moderate core hyperthermia (Tc + 1°C). Despite modest increases in great saphenous venous (GSV) blood flow (0.2 l/min), the deep venous system accounted for the majority of returning flow (common femoral vein 0.7 l/min) during intense to severe levels of heat stress. Rapid cooling of a single leg during severe whole body heat stress resulted in an equivalent blood flow reduction in the major artery supplying the thigh deep tissues only, suggesting central temperature-sensitive mechanisms contribute to skin blood flow alone. These findings further our knowledge of leg hemodynamic responses during direct heat stress and provide evidence of potentially beneficial vascular alterations during isolated limb heat stress that are equivalent to those experienced during exposure to moderate levels of whole body hyperthermia. PMID:26823344

  10. Waking the sleeping giant: Introducing new heat exchanger technology into the residential air-conditioning marketplace

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

    Chapp, T.; Voss, M.; Stephens, C.

    1998-07-01

    The Air Conditioning Industry has made tremendous strides in improvements to the energy efficiency and reliability of its product offerings over the past 40 years. These improvement can be attributed to enhancements of components, optimization of the energy cycle, and modernized and refined manufacturing techniques. During this same period, energy consumption for space cooling has grown significantly. In January of 1992, the minimum efficiency requirement for central air conditioning equipment was raised to 10 SEER. This efficiency level is likely to increase further under the auspices of the National Appliance Energy Conservation Act (NAECA). A new type of heat exchangermore » was developed for air conditioning equipment by Modine Manufacturing Company in the early 1990's. Despite significant advantages in terms of energy efficiency, dehumidification, durability, and refrigerant charge there has been little interest expressed by the air conditioning industry. A cooperative effort between Modine, various utilities, and several state energy offices has been organized to test and demonstrate the viability of this heat exchanger design throughout the nation. This paper will review the fundamentals of heat exchanger design and document this simple, yet novel technology. These experiences involving equipment retrofits have been documented with respect to the performance potential of air conditioning system constructed with PF{trademark} Heat Exchangers (generically referred to as microchannel heat exchangers) from both an energy efficiency as well as a comfort perspective. The paper will also detail the current plan to introduce 16 to 24 systems into an extended field test throughout the US which commenced in the Fall of 1997.« less

  11. Goddard Cumulus Ensemble (GCE) Model: Application for Understanding Preciptation Processes

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The global hydrological cycle is central to climate system interactions and the key to understanding their behavior. Rainfall and its associated precipitation processes are a key link in the hydrologic cycle. Fresh water provided by tropical rainfall and its variability can exert a large impact upon the structure of the upper ocean layer. In addition, approximately two-thirds of the global rain falls in the Tropics, while the associated latent heat release accounts for about three-fourths of the total heat energy for the Earth's atmosphere. Precipitation from convective cloud systems comprises a large portion of tropical heating and rainfall. Furthermore, the vertical distribution of convective latent-heat releases modulates large-scale tropical circulations (e.g., the 30-60-day intraseasonal oscillation), which, in turn, impacts midlatitude weather through teleconnection patterns such as those associated with El Nino. Shifts in these global circulations can result in prolonged periods of droughts and floods, thereby exerting a tremendous impact upon the biosphere and human habitation. And yet, monthly rainfall over the tropical oceans is still not known within a factor of two over large (5 degrees latitude by 5 degrees longitude) areas. Hence, the Tropical Rainfall Measuring Mission (TRMM), a joint U.S./Japan space project, can provide a more accurate measurement of rainfall as well as estimate the four-dimensional structure of diabatic heating over the global tropics. The distributions of rainfall and inferred heating can be used to advance our understanding of the global energy and water cycle. In addition, this information can be used for global circulation and climate models for testing and improving their parameterizations.

  12. Transpiration-Cooled Spacecraft-Insulation-Repair Fasteners

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J.; Pettit, Donald R.; Glass, David; Scotti, Stephen J.; Vaughn, Wallace Lee; Rawal, Suraj

    2012-01-01

    Transpiration-cooled fasteners are proposed that operate like an open-loop heat pipe (self-tapping screws, bolts, and spikes) for use in on-orbit repair of thermal- insulation of a space shuttle or other spacecraft. By limiting the temperature rise of such a fastener and of the adjacent repair material and thermal protection system, the transpiration cooling would contribute to the ability of the repair to retain its strength and integrity in the high-heat-flux, oxidizing environment of reentry into the atmosphere of the Earth. A typical fastener according to the proposal would include a hollow refractory-metal, refractory-composite, or ceramic screw or bolt, the central cavity of which would be occupied by a porous refractory- metal or ceramic plug that would act as both a reservoir and a wick for a transpirant liquid. The plug dimensions, the plug material, and the sizes of the pores would be chosen in conjunction with the transpirant liquid so that (1) capillary pumping could be relied upon to transport the liquid to the heated surface, where the liquid would be vaporized, and (2) the amount of liquid would suffice for protecting against the anticipated heat flux and integrated heat load.

  13. Development and Testing of a Refractory Millimeter-Wave Absorbent Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Lambot, Thomas; Myrabo, Leik; Murakami, David; Parkin, Kevin

    2014-01-01

    Central to the Millimeter-Wave Thermal Launch System (MTLS) is the millimeter-wave absorbent heat exchanger. We have developed metallic and ceramic variants, with the key challenge being the millimeter-wave absorbent coatings for each. The ceramic heat exchanger came to fruition first, demonstrating for the first time 1800 K peak surface temperatures under illumination by a 110 GHz Gaussian beam. Absorption efficiencies of up to 80 are calculated for mullite heat exchanger tubes and up to 50 are calculated for alumina tubes. These are compared with estimates based on stratified layer and finite element analyses. The problem of how to connect the 1800 K end of the ceramic tubes to a graphite outlet manifold and nozzle is solved by press fitting, or by threading the ends of the ceramic tubes and screwing them into place. The problem of how to connect the ceramic tubes to a metallic or nylon inlet pipe is solved by using soft compliant PTFE and PVC tubes that accommodate thermal deformations of the ceramic tubes during startup and operation. We show the resulting heat exchangers in static tests using argon and helium as propellants.

  14. Hypothetical Reentry Thermostructural Performance of Space Shuttle Orbiter With Missing or Eroded Thermal Protection Tiles

    NASA Technical Reports Server (NTRS)

    Ko, William L.; Gong, Leslie; Quinn, Robert D.

    2004-01-01

    This report deals with hypothetical reentry thermostructural performance of the Space Shuttle orbiter with missing or eroded thermal protection system (TPS) tiles. The original STS-5 heating (normal transition at 1100 sec) and the modified STS-5 heating (premature transition at 800 sec) were used as reentry heat inputs. The TPS missing or eroded site is assumed to be located at the center or corner (spar-rib juncture) of the lower surface of wing midspan bay 3. For cases of missing TPS tiles, under the original STS-5 heating, the orbiter can afford to lose only one TPS tile at the center or two TPS tiles at the corner (spar-rib juncture) of the lower surface of wing midspan bay 3. Under modified STS-5 heating, the orbiter cannot afford to lose even one TPS tile at the center or at the corner of the lower surface of wing midspan bay 3. For cases of eroded TPS tiles, the aluminum skin temperature rises relatively slowly with the decreasing thickness of the eroded central or corner TPS tile until most of the TPS tile is eroded away, and then increases exponentially toward the missing tile case.

  15. Mapping QTL for the traits associated with heat tolerance in Wheat (Triticum Aestivum L.)

    USDA-ARS?s Scientific Manuscript database

    High temperature (heat) stress during grain filling is a major problem in most of the wheat growing areas. Developing heat-tolerant cultivars is becoming a principal breeding goal in the Southern and Central Great Plain areas of USA. Traits associated with high temperature tolerance can be used to d...

  16. 19. VIEW OF THE BAKEOUT FURNACE, WHERE PARTS WERE HEATED ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    19. VIEW OF THE BAKE-OUT FURNACE, WHERE PARTS WERE HEATED UNDER A VACUUM TO HEAT TREAT OR TO BAKE OUT ANY IMPURITIES. (9/19/72) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  17. 12. VIEW OF THE MANIPULATOR AND PARTS HEATING FURNACE. THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    12. VIEW OF THE MANIPULATOR AND PARTS HEATING FURNACE. THE METALS WERE HEATED PRIOR TO BEING PRESSED. THE ARM IS DRAPED WITH FIRE RESISTANT MATERIAL. (2/9/79) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  18. Permanent magnet design for magnetic heat pumps using total cost minimization

    NASA Astrophysics Data System (ADS)

    Teyber, R.; Trevizoli, P. V.; Christiaanse, T. V.; Govindappa, P.; Niknia, I.; Rowe, A.

    2017-11-01

    The active magnetic regenerator (AMR) is an attractive technology for efficient heat pumps and cooling systems. The costs associated with a permanent magnet for near room temperature applications are a central issue which must be solved for broad market implementation. To address this problem, we present a permanent magnet topology optimization to minimize the total cost of cooling using a thermoeconomic cost-rate balance coupled with an AMR model. A genetic algorithm identifies cost-minimizing magnet topologies. For a fixed temperature span of 15 K and 4.2 kg of gadolinium, the optimal magnet configuration provides 3.3 kW of cooling power with a second law efficiency (ηII) of 0.33 using 16.3 kg of permanent magnet material.

  19. CATS landline installed beneath the river Tees

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

    Not Available

    Press Construction Ltd. has completed installation of the land portion of a new gas pipeline from the North Sea, including a tunnel beneath the River Tees in the north of England. The work was carried out under a multi-million dollar contract from Amoco (UK) Exploration Co. The pipeline is the land portion of the Central Area Transmission System. The 4.6-mile, 36-in. onshore pipeline connects a valve station at the CATS landfall at Coatham Sands, just south of Tees Bay, to a gas terminal north of the River Tees. This paper reports on the entire CATS system which runs for nearlymore » 250 miles from a riser platform in the Central Graben area of the North Sea to the Coatham Sands landfall and then overland to the gas terminal. The gas will fuel a new combined heat-and-power generating plant on Teesside, currently under construction by Teesside Power.« less

  20. Control Strategies to Reduce the Energy Consumption of Central Domestic Hot Water Systems

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

    Dentz, Jordan; Ansanelli, Eric; Henderson, Hugh

    Domestic hot water (DHW) heating is the second largest energy end use in U.S. buildings, exceeded only by space conditioning. Recirculation systems consisting of a pump and piping loop(s) are commonly used in multifamily buildings to reduce wait time for hot water at faucets; however, constant pumping increases energy consumption by exposing supply and return line piping to continuous heat loss, even during periods when there is no demand for hot water. In this study, ARIES installed and tested two types of recirculation controls in a pair of buildings in order to evaluate their energy savings potential. Demand control, temperaturemore » modulation controls, and the simultaneous operation of both were compared to the baseline case of constant recirculation. Additionally, interactive effects between DHW control fuel reductions and space conditioning (heating and cooling) were estimated in order to make more realistic predictions of the payback and financial viability of retrofitting DHW systems with these controls. Results showed that DHW fuel consumption reduced by 7% after implementing the demand control technique, 2% after implementing temperature modulation, and 15% after implementing demand control and temperature modulation techniques simultaneously; recirculation pump runtime was reduced to 14 minutes or less per day. With space heating and cooling interactions included, the estimated annual cost savings were 8%, 1%, and 14% for the respective control techniques. Possible complications in the installation, commissioning and operation of the controls were identified and solutions offered.« less

  1. Nonadiabatic heating of the central plasma sheet at substorm onset

    NASA Technical Reports Server (NTRS)

    Huang, C. Y.; Frank, L. A.; Rostoker, G.; Fennell, J.; Mitchell, D. G.

    1992-01-01

    Heating events in the plasma sheet boundary layer and central plasma sheet are found to occur at the onset of expansive phase activity. The main effect is a dramatic increase in plasma temperature, coincident with a partial dipolarization of the magnetic field. Fluxes of energetic particles increase without dispersion during these events which occur at all radial distances up to 23 RE, the apogee of the ISEE spacecraft. A major difference between these heating events and those observed at geosynchronous distances lies in the heating mechanism which is nonadiabatic beyond 10 RE but may be adiabatic closer to earth. The energy required to account for the increase in plasma thermal energy is comparable with that required for Joule heating of the ionosphere. The plasma sheet must be considered as a major sink in the energy balance of a substorm. Lobe magnetic pressures during these events are estimated. Change in lobe pressure are generally not correlated with onsets or intensifications of expansive phase activity.

  2. Incorporating Cutting Edge Scientific Results from the Margins-Geoprisms Program into the Undergraduate Curriculum: The Subduction Factory

    NASA Astrophysics Data System (ADS)

    Penniston-Dorland, S.; Stern, R. J.; Edwards, B. R.; Kincaid, C. R.

    2014-12-01

    The NSF-MARGINS Program funded a decade of research on continental margin processes. The NSF-GeoPRISMS Mini-lesson Project, funded by NSF-TUES, is designed to integrate fundamental results from the MARGINS program into open-source college-level curriculum. Three Subduction Factory (SubFac) mini-lessons were developed as part of this project. These include hands-on examinations of data sets representing 3 key components of the subduction zone system: 1) Heat transfer in the subducted slab; 2) Metamorphic processes happening at the plate interface; and 3) Typical magmatic products of arc systems above subduction zones. Module 1: "Slab Temperatures Control Melting in Subduction Zones, What Controls Slab Temperature?" allows students to work in groups using beads rolling down slopes as an analog for the mathematics of heat flow. Using this hands-on, exploration-based approach, students develop an intuition for the mathematics of heatflow and learn about heat conduction and advection in the subduction zone environment. Module 2: "Subduction zone metamorphism" introduces students to the metamorphic rocks that form as the subducted slab descends and the mineral reactions that characterize subduction-related metamorphism. This module includes a suite of metamorphic rocks available for instructors to use in a lab, and exercises in which students compare pressure-temperature estimates obtained from metamorphic rocks to predictions from thermal models. Module 3: "Central American Arc Volcanoes, Petrology and Geochemistry" introduces students to basic concepts in igneous petrology using the Central American volcanic arc, a MARGINS Subduction Factory focus site, as an example. The module relates data from two different volcanoes - basaltic Cerro Negro (Nicaragua) and andesitic Ilopango (El Salvador) including hand sample observations and major element geochemistry - to explore processes of mantle and crustal melting and differentiation in arc volcanism.

  3. Design and Control of Hydronic Radiant Cooling Systems

    NASA Astrophysics Data System (ADS)

    Feng, Jingjuan

    Improving energy efficiency in the Heating Ventilation and Air conditioning (HVAC) systems in buildings is critical to achieve the energy reduction in the building sector, which consumes 41% of all primary energy produced in the United States, and was responsible for nearly half of U.S. CO2 emissions. Based on a report by the New Building Institute (NBI), when HVAC systems are used, about half of the zero net energy (ZNE) buildings report using a radiant cooling/heating system, often in conjunction with ground source heat pumps. Radiant systems differ from air systems in the main heat transfer mechanism used to remove heat from a space, and in their control characteristics when responding to changes in control signals and room thermal conditions. This dissertation investigates three related design and control topics: cooling load calculations, cooling capacity estimation, and control for the heavyweight radiant systems. These three issues are fundamental to the development of accurate design/modeling tools, relevant performance testing methods, and ultimately the realization of the potential energy benefits of radiant systems. Cooling load calculations are a crucial step in designing any HVAC system. In the current standards, cooling load is defined and calculated independent of HVAC system type. In this dissertation, I present research evidence that sensible zone cooling loads for radiant systems are different from cooling loads for traditional air systems. Energy simulations, in EnergyPlus, and laboratory experiments were conducted to investigate the heat transfer dynamics in spaces conditioned by radiant and air systems. The results show that the magnitude of the cooling load difference between the two systems ranges from 7-85%, and radiant systems remove heat faster than air systems. For the experimental tested conditions, 75-82% of total heat gain was removed by radiant system during the period when the heater (simulating the heat gain) was on, while for air system, 61-63% were removed. From a heat transfer perspective, the differences are mainly because the chilled surfaces directly remove part of the radiant heat gains from a zone, thereby bypassing the time-delay effect caused by the interaction of radiant heat gain with non-active thermal mass in air systems. The major conclusions based on these findings are: 1) there are important limitations in the definition of cooling load for a mixing air system described in Chapter 18 of ASHRAE Handbook of Fundamentals when applied to radiant systems; 2) due to the obvious mismatch between how radiant heat transfer is handled in traditional cooling load calculation methods compared to its central role in radiant cooling systems, this dissertation provides improvements for the current cooling load calculation method based on the Heat Balance procedure. The Radiant Time Series method is not appropriate for radiant system applications. The findings also directly apply to the selection of space heat transfer modeling algorithms that are part of all energy modeling software. Cooling capacity estimation is another critical step in a design project. The above mentioned findings and a review of the existing methods indicates that current radiant system cooling capacity estimation methods fail to take into account incident shortwave radiation generated by solar and lighting in the calculation process. This causes a significant underestimation (up to 150% for some instances) of floor cooling capacity when solar load is dominant. Building performance simulations were conducted to verify this hypothesis and quantify the impacts of solar for different design scenarios. A new simplified method was proposed to improve the predictability of the method described in ISO 11855 when solar radiation is present. The dissertation also compares the energy and comfort benefits of the model-based predictive control (MPC) method with a fine-tuned heuristic control method when applied to a heavyweight embedded surface system. A first order dynamic model of a radiant slab system was developed for implementation in model predictive controllers. A calibrated EnergyPlus model of a typical office building in California was used as a testbed for the comparison. The results indicated that MPC is able to reduce the cooling tower energy consumption by 55% and pumping power consumption by 26%, while maintaining equivalent or even better thermal comfort conditions. In summary, the dissertation work has: (1) provided clear evidence that the fundamental heat transfer mechanisms differ between radiant and air systems. These findings have important implications for the development of accurate and reliable design and energy simulation tools; (2) developed practical design methods and guidance to aid practicing engineers who are designing radiant systems; and (3) outlined future research and design tools need to advance the state-of-knowledge and design and operating guidelines for radiant systems.

  4. Environmental Assessment: Demolition of McGuire Central Heat Plant at Joint Base McGuire-Dix-Lakehurst, New Jersey

    DTIC Science & Technology

    2012-06-01

    insulation, boiler, holding tank and duct coverings, floor tiles , window caulking/glazing, and corrugated building siding. The asbestos insulation and...facility, with the Bulk Fuel Storage area and the golf course located between them. BOMARC is located several miles from the proposed solar sites...Architectural Resources The Central Heat Plant was constructed in 1956. It is a flat- roofed building originally rectangular in form, and is now L-shaped. The

  5. Preliminary design of a solar central receiver for a site-specific repowering application (Saguaro Power Plant). Volume 1. Executive summary. Final report, October 1982-September 1983

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

    Weber, E.R.

    1983-09-01

    The preliminary design of a solar central receiver repowered gas/oil fired steam-Rankine cycle electric power generation plant was completed. The design is based on a central receiver technology using molten salt (60% NaNO/sub 3/, 40% KNO/sub 3/, by weight) for the heat transport and thermal storage fluid. Unit One of APS's Saguaro power plant located 43 km (27 mi) northwest of Tucson, AZ, is to be repowered. The selection of both the site and the molten salt central receiver promotes a near-term feasibility demonstration and cost-effective power production from an advanced solar thermal technology. The recommended system concept is tomore » repower the existing electric power generating system at the minimum useful level (66 MW/sub e/ gross) using a field of 4850 Martin Marietta second-generation (58.5 m/sup 2/) heliostats and a storage capacity of 4.0 hours. The storage capacity will be used to optimize dispatch of power to the utility system. The preliminary design was based on the use of the systems approach to design where the overall project was divided into systems, each of which is clearly bounded, and performs specific functions. The total project construction cost was estimated to be 213 million in 1983 dollars. The plant will be capable of displacing fossil energy equivalent to 2.4 million barrels of No. 6 oil in its first 10 years of operation.« less

  6. Shallow and Deep Latent Heating Modes Over Tropical Oceans Observed with TRMM PR Spectral Latent Heating Data

    NASA Technical Reports Server (NTRS)

    Takayabu, Yukari N.; Shige, Shoichi; Tao, Wei-Kuo; Hirota, Nagio

    2010-01-01

    The global hydrological cycle is central to the Earth's climate system, with rainfall and the physics of its formation acting as the key links in the cycle. Two-thirds of global rainfall occurs in the Tropics. Associated with this rainfall is a vast amount of heat, which is known as latent heat. It arises mainly due to the phase change of water vapor condensing into liquid droplets; three-fourths of the total heat energy available to the Earth's atmosphere comes from tropical rainfall. In addition, fresh water provided by tropical rainfall and its variability exerts a large impact upon the structure and motions of the upper ocean layer. Three-dimensional distributions of latent heating estimated from Tropical Rainfall Measuring Mission Precipitation Radar (TRMM PR)utilizing the Spectral Latent Heating (SLH) algorithm are analyzed. Mass-weighted and vertically integrated latent heating averaged over the tropical oceans is estimated as approx.72.6 J/s (approx.2.51 mm/day), and that over tropical land is approx.73.7 J/s (approx.2.55 mm/day), for 30degN-30degS. It is shown that non-drizzle precipitation over tropical and subtropical oceans consists of two dominant modes of rainfall systems, deep systems and congestus. A rough estimate of shallow mode contribution against the total heating is about 46.7 % for the average tropical oceans, which is substantially larger than 23.7 % over tropical land. While cumulus congestus heating linearly correlates with the SST, deep mode is dynamically bounded by large-scale subsidence. It is notable that substantial amount of rain, as large as 2.38 mm day-1 in average, is brought from congestus clouds under the large-scale subsiding circulation. It is also notable that even in the region with SST warmer than 28 oC, large-scale subsidence effectively suppresses the deep convection, remaining the heating by congestus clouds. Our results support that the entrainment of mid-to-lower-tropospheric dry air, which accompanies the large-scale subsidence is the major factor suppressing the deep convection. Therefore, representation of the realistic entrainment is very important for proper reproduction of precipitation distribution and resultant large-scale circulation.

  7. Temperature analysis during bonding of brackets using LED or halogen light base units.

    PubMed

    Silva, Paulo César Gomes; De Fátima Zanirato Lizarelli, Rosane; Moriyama, Lílian Tan; De Toledo Porto Neto, Sizenando; Bagnato, Vanderlei Salvador

    2005-02-01

    The purpose of our investigation is to compare the intrapulpal temperature changes following blue LED system and halogen lamp irradiation at the enamel surface of permanent teeth. The fixation of brackets using composite resin is more comfortable and faster when using a photo-curable composite. Several light sources can be used: halogens, arc plasma, lasers, and recently blue LED systems. An important aspect to be observed during such a procedures is the temperature change. In this study, we have used nine human extracted permanent teeth: three central incisors, three lateral incisors, and three canines. Teeth were exposed to two light sources: blue LED system (preliminary commercial model LEC 470-II) and halogen lamp (conventional photo-cure equipment). The surface of teeth was exposed for 20, 40, and 60 sec at the buccal and lingual enamel surface with an angle of 45 degrees. Temperature values measured by a thermistor placed at pulpar chamber were read in time intervals of 1 sec. We obtained plots showing the temperature evolution as a function of time for each experiment. There is a correlation between heating quantity and exposition time of light source: with increasing exposition time, heating increases into the pulpal chamber. The halogen lamp showed higher heating than the LED system, which showed a shorter time of cooling than halogen lamp. The blue LED system seems like the indicated light source for photo-cure of composite resin during the bonding of brackets. The fixation of brackets using composite resin is more comfortable and faster when using a photo-curable composite. Blue LED equipment did not heat during its use. This could permit a shorter clinical time of operation and better performance.

  8. Space Station thermal storage/refrigeration system research and development

    NASA Astrophysics Data System (ADS)

    Dean, W. G.; Karu, Z. S.

    1993-02-01

    Space Station thermal loading conditions represent an order of magnitude increase over current and previous spacecraft such as Skylab, Apollo, Pegasus III, Lunar Rover Vehicle, and Lockheed TRIDENT missiles. Thermal storage units (TSU's) were successfully used on these as well as many applications for ground based solar energy storage applications. It is desirable to store thermal energy during peak loading conditions as an alternative to providing increased radiator surface area which adds to the weight of the system. Basically, TSU's store heat by melting a phase change material (PCM) such as a paraffin. The physical property data for the PCM's used in the design of these TSU's is well defined in the literature. Design techniques are generally well established for the TSU's. However, the Space Station provides a new challenge in the application of these data and techniques because of three factors: the large size of the TSU required, the integration of the TSU for the Space Station thermal management concept with its diverse opportunities for storage application, and the TSU's interface with a two-phase (liquid/vapor) thermal bus/central heat rejection system. The objective in the thermal storage research and development task was to design, fabricate, and test a demonstration unit. One test article was to be a passive thermal storage unit capable of storing frozen food at -20 F for a minimum of 90 days. A second unit was to be capable of storing frozen biological samples at -94 F, again for a minimum of 90 days. The articles developed were compatible with shuttle mission conditions, including safety and handling by astronauts. Further, storage rack concepts were presented so that these units can be integrated into Space Station logistics module storage racks. The extreme sensitivity of spacecraft radiator systems design-to-heat rejection temperature requirements is well known. A large radiator area penalty is incurred if low temperatures are accommodated via a single centralized radiator system. As per the scope of work of this task, the applicability of refrigeration system tailored to meet the specialized requirements of storage of food and biological samples was investigated. The issues addressed were the anticipated power consumption and feasible designs and cycles for meeting specific storage requirements. Further, development issues were assessed related to the operation of vapor compression systems in micro-gravity addressing separation of vapor and liquid phases (via capillary systems).

  9. Space Station thermal storage/refrigeration system research and development

    NASA Technical Reports Server (NTRS)

    Dean, W. G.; Karu, Z. S.

    1993-01-01

    Space Station thermal loading conditions represent an order of magnitude increase over current and previous spacecraft such as Skylab, Apollo, Pegasus III, Lunar Rover Vehicle, and Lockheed TRIDENT missiles. Thermal storage units (TSU's) were successfully used on these as well as many applications for ground based solar energy storage applications. It is desirable to store thermal energy during peak loading conditions as an alternative to providing increased radiator surface area which adds to the weight of the system. Basically, TSU's store heat by melting a phase change material (PCM) such as a paraffin. The physical property data for the PCM's used in the design of these TSU's is well defined in the literature. Design techniques are generally well established for the TSU's. However, the Space Station provides a new challenge in the application of these data and techniques because of three factors: the large size of the TSU required, the integration of the TSU for the Space Station thermal management concept with its diverse opportunities for storage application, and the TSU's interface with a two-phase (liquid/vapor) thermal bus/central heat rejection system. The objective in the thermal storage research and development task was to design, fabricate, and test a demonstration unit. One test article was to be a passive thermal storage unit capable of storing frozen food at -20 F for a minimum of 90 days. A second unit was to be capable of storing frozen biological samples at -94 F, again for a minimum of 90 days. The articles developed were compatible with shuttle mission conditions, including safety and handling by astronauts. Further, storage rack concepts were presented so that these units can be integrated into Space Station logistics module storage racks. The extreme sensitivity of spacecraft radiator systems design-to-heat rejection temperature requirements is well known. A large radiator area penalty is incurred if low temperatures are accommodated via a single centralized radiator system. As per the scope of work of this task, the applicability of refrigeration system tailored to meet the specialized requirements of storage of food and biological samples was investigated. The issues addressed were the anticipated power consumption and feasible designs and cycles for meeting specific storage requirements. Further, development issues were assessed related to the operation of vapor compression systems in micro-gravity addressing separation of vapor and liquid phases (via capillary systems).

  10. Heat Tolerance of the Brown Recluse Spider (Araneae: Sicariidae): Potential for Pest Control.

    PubMed

    Cramer, Kenneth L; Zagar, Lindsey M

    2016-02-01

    The brown recluse spider, Loxosceles reclusa Gertsch & Mulaik, is a well-known venomous spider common in the south-central United States where infestations can reach thousands of individuals in a single structure. Bites from this spider pose a risk of dermonecrotic lesions (loxoscelism) or, rarely, more serious systemic effects. The heat tolerance of this spider is understudied but may offer an alternative pest control solution to pesticides or fumigation, both of which have their disadvantages. We subjected brown recluse spiders to increasing temperatures to establish the upper lethal temperature (LT). Using probit analysis to generate probability of mortality at increasing temperatures, we then exposed adult spiders to the observed LT50 to simulate whole-room heat treatment. Laboratory results predict exposure to 48°C for 130 min will achieve 100% mortality of adult spiders. Field tests need to be conducted to determine the efficacy of heat treatment in a variety of real-world situations. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  11. Excessive heat-associated gingival necrosis: a case report.

    PubMed

    Barnes, P L; Rossi-Fedele, G

    2017-09-01

    Heat-delivery devices have been associated with relatively high temperatures. Previous basic research studies suggest that the risk for periodontal tissues is negligible, as the presence of the root filling materials, amongst other factors, reduce the risk of overheating. This report describes the case of a 45 year old male, who was undergoing restorative treatment in a multi-specialty dental practice. As part of his overall treatment planning, orthograde root canal retreatment for his maxillary left incisor teeth was deemed necessary, due to chronic apical periodontitis. Following cold lateral compaction, the coronal portion of the core material was severed using a System B Heat Source (Kerr Dental, Orange, CA, USA), with the patient reporting pain as well as a burning sensation. The following day the patient was seen by a periodontist and gingival necrosis in relation to the central incisor was found. The most likely cause of the complication was considered to be excessive heat during the operative procedure. The patient was followed up for a 2-year period and the soft tissues returned to their original condition without the need for periodontal treatment. © 2017 Australian Dental Association.

  12. Composite Study Of Aerosol Long-Range Transport Events From East Asia And North America

    NASA Astrophysics Data System (ADS)

    Jiang, X.; Waliser, D. E.; Guan, B.; Xavier, P.; Petch, J.; Klingaman, N. P.; Woolnough, S.

    2011-12-01

    While the Madden-Julian Oscillation (MJO) exerts pronounced influences on global climate and weather systems, current general circulation models (GCMs) exhibit rather limited capability in representing this prominent tropical variability mode. Meanwhile, the fundamental physics of the MJO are still elusive. Given the central role of the diabatic heating for prevailing MJO theories and demands for reducing the model deficiencies in simulating the MJO, a global model inter-comparison project on diabatic processes and vertical heating structure associated with the MJO has been coordinated through a joint effort by the WCRP-WWRP/THORPEX YOTC MJO Task Force and GEWEX GASS Program. In this presentation, progress of this model inter-comparison project will be reported, with main focus on climate simulations from about 27 atmosphere-only and coupled GCMs. Vertical structures of heating and diabatic processes associated with the MJO based on multi-model simulations will be presented along with their reanalysis and satellite estimate counterparts. Key processes possibly responsible for a realistic simulation of the MJO, including moisture-convection interaction, gross moist stability, ocean coupling, and surface heat flux, will be discussed.

  13. Buildings operations and ETS exposure.

    PubMed Central

    Spengler, J D

    1999-01-01

    Mechanical systems are used in buildings to provide conditioned air, dissipate thermal loads, dilute contaminants, and maintain pressure differences. The characteristics of these systems and their operations h implications for the exposures of workers to environmental tobacco smoke (ETS) and for the control of these exposures. This review describes the general features of building ventilation systems and the efficacy of ventilation for controlling contaminant concentrations. Ventilation can reduce the concentration of ETS through dilution, but central heating, ventilating, and air conditioning (HVAC) can also move air throughout a building that has been contaminated by ETS. An understanding of HVAC systems is needed to develop models for exposures of workers to ETS. Images Figure 1 Figure 2 Figure 3 PMID:10375293

  14. Ablative stabilization of Rayleigh-Taylor instabilities resulting from a laser-driven radiative shock

    NASA Astrophysics Data System (ADS)

    Huntington, C. M.; Shimony, A.; Trantham, M.; Kuranz, C. C.; Shvarts, D.; Di Stefano, C. A.; Doss, F. W.; Drake, R. P.; Flippo, K. A.; Kalantar, D. H.; Klein, S. R.; Kline, J. L.; MacLaren, S. A.; Malamud, G.; Miles, A. R.; Prisbrey, S. T.; Raman, K. S.; Remington, B. A.; Robey, H. F.; Wan, W. C.; Park, H.-S.

    2018-05-01

    The Rayleigh-Taylor (RT) instability is a common occurrence in nature, notably in astrophysical systems like supernovae, where it serves to mix the dense layers of the interior of an exploding star with the low-density stellar wind surrounding it, and in inertial confinement fusion experiments, where it mixes cooler materials with the central hot spot in an imploding capsule and stifles the desired nuclear reactions. In both of these examples, the radiative flux generated by strong shocks in the system may play a role in partially stabilizing RT instabilities. Here, we present experiments performed on the National Ignition Facility, designed to isolate and study the role of radiation and heat conduction from a shock front in the stabilization of hydrodynamic instabilities. By varying the laser power delivered to a shock-tube target with an embedded, unstable interface, the radiative fluxes generated at the shock front could be controlled. We observe decreased RT growth when the shock significantly heats the medium around it, in contrast to a system where the shock did not produce significant heating. Both systems are modeled with a modified set of buoyancy-drag equations accounting for ablative stabilization, and the experimental results are consistent with ablative stabilization when the shock is radiative. This result has important implications for our understanding of astrophysical radiative shocks and supernova radiative hydrodynamics [Kuranz et al., Nature Communications 9(1), 1564 (2018)].

  15. Retrieved Vertical Profiles of Latent Heat Release Using TRMM Rainfall Products

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Lang, S.; Olson, W. S.; Meneghini, R.; Yang, S.; Simpson, J.; Kummerow, C.; Smith, E.

    2000-01-01

    This paper represents the first attempt to use TRMM rainfall information to estimate the four dimensional latent heating structure over the global tropics for February 1998. The mean latent heating profiles over six oceanic regions (TOGA COARE IFA, Central Pacific, S. Pacific Convergence Zone, East Pacific, Indian Ocean and Atlantic Ocean) and three continental regions (S. America, Central Africa and Australia) are estimated and studied. The heating profiles obtained from the results of diagnostic budget studies over a broad range of geographic locations are used to provide comparisons and indirect validation for the heating algorithm estimated heating profiles. Three different latent heating algorithms, the Goddard Convective-Stratiform (CSH) heating, the Goddard Profiling (GPROF) heating, and the Hydrometeor heating (HH) are used and their results are intercompared. The horizontal distribution or patterns of latent heat release from the three different heating retrieval methods are quite similar. They all can identify the areas of major convective activity (i.e., a well defined ITCZ in the Pacific, a distinct SPCZ) in the global tropics. The magnitude of their estimated latent heating release is also not in bad agreement with each other and with those determined from diagnostic budget studies. However, the major difference among these three heating retrieval algorithms is the altitude of the maximum heating level. The CSH algorithm estimated heating profiles only show one maximum heating level, and the level varies between convective activity from various geographic locations. These features are in good agreement with diagnostic budget studies. By contrast, two maximum heating levels were found using the GPROF heating and HH algorithms. The latent heating profiles estimated from all three methods can not show cooling between active convective events. We also examined the impact of different TMI (Multi-channel Passive Microwave Sensor) and PR (Precipitation Radar) rainfall information on latent heating structures.

  16. Soviet steam generator technology: fossil fuel and nuclear power plants. [Glossary included

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

    Rosengaus, J.

    1987-01-01

    In the Soviet Union, particular operational requirements, coupled with a centralized planning system adopted in the 1920s, have led to a current technology which differs in significant ways from its counterparts elsewhere in the would and particularly in the United States. However, the monograph has a broader value in that it traces the development of steam generators in response to the industrial requirements of a major nation dealing with the global energy situation. Specifically, it shows how Soviet steam generator technology evolved as a result of changing industrial requirements, fuel availability, and national fuel utilization policy. The monograph begins withmore » a brief technical introduction focusing on steam-turbine power plants, and includes a discussion of the Soviet Union's regional power supply (GRES) networks and heat and power plant (TETs) systems. TETs may be described as large central co-generating stations which, in addition to electricity, provide heat in the form of steam and hot water. Plants of this type are a common feature of the USSR today. The adoption of these cogeneration units as a matter of national policy has had a central influence on Soviet steam generator technology which can be traced throughout the monograph. The six chapters contain: a short history of steam generators in the USSR; steam generator design and manufacture in the USSR; boiler and furnace assemblies for fossil fuel-fired power stations; auxiliary components; steam generators in nuclear power plants; and the current status of the Soviet steam generator industry. Chapters have been abstracted separately. A glossary is included containing abbreviations and acronyms of USSR organizations. 26 references.« less

  17. 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.

  18. Potential for a significant deep basin geothermal system in Tintic Valley, Utah

    NASA Astrophysics Data System (ADS)

    Hardwick, C.; Kirby, S.

    2014-12-01

    The combination of regionally high heat flow, deep basins, and permeable reservoir rocks in the eastern Great Basin may yield substantial new geothermal resources. We explore a deep sedimentary basin geothermal prospect beneath Tintic Valley in central Utah using new 2D and 3D models coupled with existing estimates of heat flow, geothermometry, and shallow hydrologic data. Tintic Valley is a sediment-filled basin bounded to the east and west by bedrock mountain ranges where heat-flow values vary from 85 to over 240 mW/m2. Based on modeling of new and existing gravity data, a prominent 30 mGal low indicates basin fill thickness may exceed 2 km. The insulating effect of relatively low thermal conductivity basin fill in Tintic Valley, combined with typical Great Basin heat flow, predict temperatures greater than 150 °C at 3 km depth. The potential reservoir beneath the basin fill is comprised of Paleozoic carbonate and clastic rocks. The hydrology of the Tintic Valley is characterized by a shallow, cool groundwater system that recharges along the upper reaches of the basin and discharges along the valley axis and to a series of wells. The east mountain block is warm and dry, with groundwater levels just above the basin floor and temperatures >50 °C at depth. The west mountain block contains a shallow, cool meteoric groundwater system. Fluid temperatures over 50 °C are sufficient for direct-use applications, such as greenhouses and aquaculture, while temperatures exceeding 140°C are suitable for binary geothermal power plants. The geologic setting and regionally high heat flow in Tintic Valley suggest a geothermal resource capable of supporting direct-use geothermal applications and binary power production could be present.

  19. Attribution of the July–August 2013 heat event in Central and Eastern China to anthropogenic greenhouse gas emissions

    DOE PAGES

    Ma, Shuangmei; Zhou, Tianjun; Stone, Dáithí A.; ...

    2017-05-19

    In the midsummer of 2013, Central and Eastern China (CEC) was hit by an extraordinary heat event, with the region experiencing the warmest July-August on record. To explore how human-induced greenhouse gas emissions and natural internal variability contributed to this heat event, we compare observed July-August mean surface air temperature wit h that simulated by climate models. We find that both atmospheric natural variability and anthropogenic factors contributed to this heat event. This extreme warm midsummer was associated with a positive high-pressure anomaly that was closely related to the stochastic behavior of atmospheric circulation. Diagnosis of CMIP5 models and largemore » ensembles of two atmospheric models indicates that human influence has substantially increased the chance of warm mid-summers such as 2013 in CEC, although the exact estimated increase depends on the selection of climate models.« less

  20. Optimizing the parameters of heat transmission in a small heat exchanger with spiral tapes cut as triangles and Aluminum oxide nanofluid using central composite design method

    NASA Astrophysics Data System (ADS)

    Ghasemi, Nahid; Aghayari, Reza; Maddah, Heydar

    2018-07-01

    The present study aims at optimizing the heat transmission parameters such as Nusselt number and friction factor in a small double pipe heat exchanger equipped with rotating spiral tapes cut as triangles and filled with aluminum oxide nanofluid. The effects of Reynolds number, twist ratio (y/w), rotating twisted tape and concentration (w%) on the Nusselt number and friction factor are also investigated. The central composite design and the response surface methodology are used for evaluating the responses necessary for optimization. According to the optimal curves, the most optimized value obtained for Nusselt number and friction factor was 146.6675 and 0.06020, respectively. Finally, an appropriate correlation is also provided to achieve the optimal model of the minimum cost. Optimization results showed that the cost has decreased in the best case.

  1. Optimizing the parameters of heat transmission in a small heat exchanger with spiral tapes cut as triangles and Aluminum oxide nanofluid using central composite design method

    NASA Astrophysics Data System (ADS)

    Ghasemi, Nahid; Aghayari, Reza; Maddah, Heydar

    2018-02-01

    The present study aims at optimizing the heat transmission parameters such as Nusselt number and friction factor in a small double pipe heat exchanger equipped with rotating spiral tapes cut as triangles and filled with aluminum oxide nanofluid. The effects of Reynolds number, twist ratio (y/w), rotating twisted tape and concentration (w%) on the Nusselt number and friction factor are also investigated. The central composite design and the response surface methodology are used for evaluating the responses necessary for optimization. According to the optimal curves, the most optimized value obtained for Nusselt number and friction factor was 146.6675 and 0.06020, respectively. Finally, an appropriate correlation is also provided to achieve the optimal model of the minimum cost. Optimization results showed that the cost has decreased in the best case.

  2. Attribution of the July–August 2013 heat event in Central and Eastern China to anthropogenic greenhouse gas emissions

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

    Ma, Shuangmei; Zhou, Tianjun; Stone, Dáithí A.

    In the midsummer of 2013, Central and Eastern China (CEC) was hit by an extraordinary heat event, with the region experiencing the warmest July-August on record. To explore how human-induced greenhouse gas emissions and natural internal variability contributed to this heat event, we compare observed July-August mean surface air temperature wit h that simulated by climate models. We find that both atmospheric natural variability and anthropogenic factors contributed to this heat event. This extreme warm midsummer was associated with a positive high-pressure anomaly that was closely related to the stochastic behavior of atmospheric circulation. Diagnosis of CMIP5 models and largemore » ensembles of two atmospheric models indicates that human influence has substantially increased the chance of warm mid-summers such as 2013 in CEC, although the exact estimated increase depends on the selection of climate models.« less

  3. Modeling, Analysis, and Control of a Hypersonic Vehicle with Significant Aero-Thermo-Elastic-Propulsion Interactions: Elastic, Thermal and Mass Uncertainty

    NASA Astrophysics Data System (ADS)

    Khatri, Jaidev

    This thesis examines themodeling, analysis, and control system design issues for scramjet powered hypersonic vehicles. A nonlinear three degrees of freedom longitudinal model which includes aero-propulsion-elasticity effects was used for all analyses. This model is based upon classical compressible flow and Euler-Bernouli structural concepts. Higher fidelity computational fluid dynamics and finite element methods are needed for more precise intermediate and final evaluations. The methods presented within this thesis were shown to be useful for guiding initial control relevant design. The model was used to examine the vehicle's static and dynamic characteristics over the vehicle's trimmable region. The vehicle has significant longitudinal coupling between the fuel equivalency ratio (FER) and the flight path angle (FPA). For control system design, a two-input two-output plant (FER - elevator to speed-FPA) with 11 states (including 3 flexible modes) was used. Velocity, FPA, and pitch were assumed to be available for feedback. Aerodynamic heat modeling and design for the assumed TPS was incorporated to original Bolender's model to study the change in static and dynamic properties. De-centralized control stability, feasibility and limitations issues were dealt with the change in TPS elasticity, mass and physical dimension. The impact of elasticity due to TPS mass, TPS physical dimension as well as prolonged heating was also analyzed to understand performance limitations of de-centralized control designed for nominal model.

  4. Microcomputer keeps watch at Emerald Mine

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

    Not Available

    1987-04-01

    This paper reviews the computerized mine monitoring system set up at the Emerald Mine, SW Pennsylvania, USA. This coal mine has pioneered the automation of many production and safety features and this article covers their work in fire detection and conveyor belt monitoring. A central computer control room can safely watch over the whole underground mining operation using one 25 inch colour monitor. These new data-acquisition systems will lead the way, in the future, to safer move efficient coal mining. Multi-point monitoring of carbon monoxide, heat anomalies, toxic gases and the procedures in conveyor belt operation from start-up to closedown.

  5. 77 FR 1649 - Energy Conservation Program for Consumer Products and Certain Commercial and Industrial Equipment...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-01-11

    ... of a central air conditioner which is designed to remove the heat absorbed by the refrigerant and to... heat absorbed by the refrigerant and to transfer it to the outside environment, and which consists of... pump that is designed to transfer heat between the refrigerant and the outdoor air, and which consists...

  6. Relationship between lunar tidal enhancements in the equatorial electrojet and tropospheric eddy heat flux during stratospheric sudden warmings

    NASA Astrophysics Data System (ADS)

    Siddiqui, T. A.; Yamazaki, Y.; Stolle, C.; Lühr, H.; Matzka, J.

    2017-12-01

    A number of studies in recent years have reported about the lunar tidal enhancements in the equatorial electrojet (EEJ) from ground- and space-based magnetometer measurements during stratospheric sudden warming (SSW) events. In this study, we make use of the ground magnetometer recordings at Huancayo observatory in Peru for the years 1978 - 2013 to derive a relationship between the lunar tidal enhancements in the EEJ and tropospheric eddy heat fluxes at 100 hPa during the SSW events. Tropospheric eddy heat fluxes are used to quantify the amount of wave activity entering the stratosphere. Anomalously large upward wave activity is known to precede the polar vortex breakdown during SSWs. We make use of the superposed epoch analysis method to determine the temporal relations between lunar tidal enhancements and eddy heat flux anomalies during SSWs, in order to demonstrate the causal relationship between these two phenomena. We also compare the lunar tidal enhancements and eddy heat flux anomalies for vortex split and for vortex displaced SSWs. It is found that larger lunar tidal enhancements are recorded for vortex split events, as compared to vortex displaced events. This confirms earlier observation; larger heat flux anomalies are recorded during vortex split SSW events than the heat flux anomalies during vortex displaced SSW events. Further, the temporal relations of lunar tidal enhancements in the EEJ have been compared separately for both the QBO phases and with the phases of the moon with respect to the central epoch of SSWs by means of the superposed epoch analysis approach. The EEJ lunar tidal enhancements in the east phase of QBO are found to be larger than the lunar tidal enhancements in the west phase of QBO. The phase of moon relative to the central SSW epoch also affects the lunar tidal enhancement in the EEJ. It is found that the lunar tidal enhancements are significantly larger when the day of new or full moon lies near the central SSW epoch, as compared to cases when new or full moon occur further away from the central SSW epoch.

  7. Temperature measuring analysis of the nuclear reactor fuel assembly

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

    Urban, F., E-mail: jozef.bereznai@stuba.sk, E-mail: zdenko.zavodny@stuba.sk; Kučák, L., E-mail: jozef.bereznai@stuba.sk, E-mail: zdenko.zavodny@stuba.sk; Bereznai, J., E-mail: jozef.bereznai@stuba.sk, E-mail: zdenko.zavodny@stuba.sk

    2014-08-06

    Study was based on rapid changes of measured temperature values from the thermocouple in the VVER 440 nuclear reactor fuel assembly. Task was to determine origin of fluctuations of the temperature values by experiments on physical model of the fuel assembly. During an experiment, heated water was circulating in the system and cold water inlet through central tube to record sensitivity of the temperature sensor. Two positions of the sensor was used. First, just above the central tube in the physical model fuel assembly axis and second at the position of the thermocouple in the VVER 440 nuclear reactor fuelmore » assembly. Dependency of the temperature values on time are presented in the diagram form in the paper.« less

  8. Origin and dynamics of emission line clouds in cooling flow environments

    NASA Technical Reports Server (NTRS)

    Loewenstein, Michael

    1990-01-01

    The author suggests that since clouds are born co-moving in a turbulent intra-cluster medium (ICM), the allowed parameter space can now be opened up to a more acceptable range. Large-scale motions can be driven in the central parts of cooling flows by a number of mechanisms including the motion of the central and other galaxies, and the dissipation of advected, focussed rotational and magnetic energy. In addition to the velocity width paradox, two other paradoxes (Heckman et al. 1989) can be solved if the ICM is turbulent. Firstly, the heating source for the emission line regions has always been puzzling - line luminosities are extremely high for a given (optical or radio) galaxy luminosity compared to those in non-cooling flow galaxies, therefore a mechanism peculiar to cooling flows must be at work. However most, if not all, previously suggested heating mechanisms either fail to provide enough ionization or give the wrong line ratios, or both. The kinetic energy in the turbulence provides a natural energy source if it can be efficiently converted to cloud heat. Researchers suggest that this can be done via magneto-hydrodynamic waves through plasma slip. Secondly, while the x ray observations indicate extended mass deposition, the optical line emission is more centrally concentrated. Since many of the turbulence-inducing mechanisms are strongest in the central regions of the ICM, so is the method of heating. In other words material is dropping out everywhere but only being lit up in the center.

  9. Wellbore heat flow from the Toa Baja scientific drillhole, Puerto Rico

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

    Anderson, R.N.; Larue, D.K.

    1991-03-01

    Heat flow values, determined from temperature logs and estimates of thermal conductivity from geophysical logs range from 23 to 37 mW/m{sup 2} from 800 to 2,500 m depth in the Toa Baja scientific drillhole on the north, central coast of Puerto Rico. Near the target seismic reflector at the base of the well, an active hydrothermal system was encountered in which heat flow of up to 90 mW/m{sup 2} was found in a mineralized zone beneath a volcanic sill or flow. The heat flow then dropped to 50 mW/m{sub 2} beneath this subhorizontal flow zone. The mining of heat frommore » downdip is proposed to account for this thermal anomaly, as well as the scatter in the heat flow determined from the few other wells drilled into Puerto Rico. The time-temperature history of the well indicates that Eocene volcaniclastics of the lower 2 km were deposited into a geothermal gradient of 60C/km north of an active arc (heat flow estimated to have been 120-180 mW/m{sup 2}). Uplift, erosion and cooling occurred between 40 and 30 Ma. Reburial and deposition of Oligocene-Miocene Limestones produced the present-day geothermal gradient of 15C/km (heat flow of 30-50 mW/m{sup 2}). Based upon comparisons with slab cooling models, the crustal thickness beneath Puerto Rico is estimated to be closer to continental then oceanic.« less

  10. Wireless ZigBee home automation system

    NASA Astrophysics Data System (ADS)

    Craciunescu, Razvan; Halunga, Simona; Fratu, Octavian

    2015-02-01

    The home automation system concept existed for many years but in the last decade, due to the rapid development of sensors and wireless technologies, a large number of various such "intelligent homes" have been developed. The purpose of the present paper is to demonstrate the flexibility, reliability and affordability of home automation projects, based on a simple and affordable implementation. A wireless sensing and control system have been developed and tested, having a number of basic functionalities such as switching on/off the light according to ambient lighting and turning on/off the central heating. The system has been built around low power microcontrollers and ZigBee modems for wireless communication, using a set of Vishay 640 thermistor sensors for temperature measurements and Vishay LDR07 photo-resistor for humidity measurements. A trigger is activated when the temperature or light measurements are above/below a given threshold and a command is transmitted to the central unit through the ZigBee radio module. All the data processing is performed by a low power microcontroller both at the sensing device and at the control unit.

  11. Cardiopulmonary baroreceptor control of muscle sympathetic nerve activity in heat-stressed humans

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.; Etzel, R. A.; Farr, D. B.

    1999-01-01

    Whole body heating decreases central venous pressure (CVP) while increasing muscle sympathetic nerve activity (MSNA). In normothermia, similar decreases in CVP elevate MSNA, presumably via cardiopulmonary baroreceptor unloading. The purpose of this project was to identify whether increases in MSNA during whole body heating could be attributed to cardiopulmonary baroreceptor unloading coincident with the thermal challenge. Seven subjects were exposed to whole body heating while sublingual temperature, skin blood flow, heart rate, arterial blood pressure, and MSNA were monitored. During the heat stress, 15 ml/kg warmed saline was infused intravenously over 7-10 min to increase CVP and load the cardiopulmonary baroreceptors. We reported previously that this amount of saline was sufficient to return CVP to pre-heat stress levels. Whole body heating increased MSNA from 25 +/- 3 to 39 +/- 3 bursts/min (P < 0. 05). Central blood volume expansion via rapid saline infusion did not significantly decrease MSNA (44 +/- 4 bursts/min, P > 0.05 relative to heat stress period) and did not alter mean arterial blood pressure (MAP) or pulse pressure. To identify whether arterial baroreceptor loading decreases MSNA during heat stress, in a separate protocol MAP was elevated via steady-state infusion of phenylephrine during whole body heating. Increasing MAP from 82 +/- 3 to 93 +/- 4 mmHg (P < 0.05) caused MSNA to decrease from 36 +/- 3 to 15 +/- 4 bursts/min (P < 0.05). These data suggest that cardiopulmonary baroreceptor unloading during passive heating is not the primary mechanism resulting in elevations in MSNA. Moreover, arterial baroreceptors remain capable of modulating MSNA during heat stress.

  12. Recent GPS Results at SLAC

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

    Behrend, Dirk; Imfeld, Hans L.; /SLAC

    2005-08-17

    The Alignment Engineering Group (AEG) makes use of GPS technology for fulfilling part of its above ground surveying tasks at SLAC since early 2002. A base station (SLAC M40) has been set up at a central location of the SLAC campus serving both as master station for real-time kinematic (RTK) operations and as datum point for local GPS campaigns. The Leica RS500 system is running continuously and the GPS data are collected both externally (logging PC) and internally (receiver flashcard). The external logging is facilitated by a serial to Ethernet converter and an Ethernet connection at the station. Internal loggingmore » (ring buffer) is done for data security purposes. The weatherproof boxes for the instrumentation are excellent shelters against rain and wind, but do heat up considerably in sun light. Whereas the GPS receiver showed no problems, the Pacific Crest PDL 35 radio shut down several times due to overheating disrupting the RTK operations. In order to prevent heat-induced shutdowns, a protection against direct sun exposure (shading) and a constant air circulation system (ventilation) were installed. As no further shutdowns have occurred so far, it appears that the two measures successfully mended the heat problem.« less

  13. Century/millennium internal climate oscillations in an ocean-atmosphere-continental ice sheet model

    NASA Technical Reports Server (NTRS)

    Birchfield, Edward G.; Wang, Huaxiao; Rich, Jonathan J.

    1994-01-01

    We demonstrate in a simple climate model that there exist nonlinear feedbacks between the atmosphere, ocean, and ice sheets capable of producing century/millennium timescale internal oscillations resembling those seen in the paleoclimate record. Feedbacks involve meridional heat and salt transports in the North Atlantic, surface ocean freshwater fluxes associated with melting and growing continental ice sheets in the northen hemisphere and with Atlantic to Pacific water vapor transport. The positive feedback between the production of North Atlantic Deep Water (NADW) and the meridional salt transport by the Atlantic thermohaline circulation tends to destabilize the climate system, while the negative feedback between the freshwater flux, either to or from the continental ice sheets, and meridional heat flux to the high-latitude North Atlantic, accomplished by the thermohaline circulation, stabilizes the system. The thermohaline circulation plays a central role in both positive and negative feedbacks because of its transport of both heat and salt. Because of asymmetries between the growth and melt phases the oscillations are, in general, accompanied by a growing or decreasing ice volume over each cycle, which in the model is reflected by increasing or decreasing mean salinity.

  14. An Improved Model of Heat-Induced Hyperalgesia—Repetitive Phasic Heat Pain Causing Primary Hyperalgesia to Heat and Secondary Hyperalgesia to Pinprick and Light Touch

    PubMed Central

    Henrich, Florian; Magerl, Walter; May, Arne

    2014-01-01

    This study tested a modified experimental model of heat-induced hyperalgesia, which improves the efficacy to induce primary and secondary hyperalgesia and the efficacy-to-safety ratio reducing the risk of tissue damage seen in other heat pain models. Quantitative sensory testing was done in eighteen healthy volunteers before and after repetitive heat pain stimuli (60 stimuli of 48°C for 6 s) to assess the impact of repetitive heat on somatosensory function in conditioned skin (primary hyperalgesia area) and in adjacent skin (secondary hyperalgesia area) as compared to an unconditioned mirror image control site. Additionally, areas of flare and secondary hyperalgesia were mapped, and time course of hyperalgesia determined. After repetitive heat pain conditioning we found significant primary hyperalgesia to heat, and primary and secondary hyperalgesia to pinprick and to light touch (dynamic mechanical allodynia). Acetaminophen (800 mg) reduced pain to heat or pinpricks only marginally by 11% and 8%, respectively (n.s.), and had no effect on heat hyperalgesia. In contrast, the areas of flare (−31%) and in particular of secondary hyperalgesia (−59%) as well as the magnitude of hyperalgesia (−59%) were significantly reduced (all p<0.001). Thus, repetitive heat pain induces significant peripheral sensitization (primary hyperalgesia to heat) and central sensitization (punctate hyperalgesia and dynamic mechanical allodynia). These findings are relevant to further studies using this model of experimental heat pain as it combines pronounced peripheral and central sensitization, which makes a convenient model for combined pharmacological testing of analgesia and anti-hyperalgesia mechanisms related to thermal and mechanical input. PMID:24911787

  15. 76 FR 65616 - Energy Conservation Program for Consumer Products: Test Procedures for Residential Central Air...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-24

    ... measure the energy efficiency, energy use or estimated annual operating cost of a covered product over an... the June 2010 NOPR would be used to determine the average power consumption of a residential central... residential central air conditioners, the unit's average power consumption during the heating season...

  16. Climate change scenarios of heat waves in Central Europe and their uncertainties

    NASA Astrophysics Data System (ADS)

    Lhotka, Ondřej; Kyselý, Jan; Farda, Aleš

    2018-02-01

    The study examines climate change scenarios of Central European heat waves with a focus on related uncertainties in a large ensemble of regional climate model (RCM) simulations from the EURO-CORDEX and ENSEMBLES projects. Historical runs (1970-1999) driven by global climate models (GCMs) are evaluated against the E-OBS gridded data set in the first step. Although the RCMs are found to reproduce the frequency of heat waves quite well, those RCMs with the coarser grid (25 and 50 km) considerably overestimate the frequency of severe heat waves. This deficiency is improved in higher-resolution (12.5 km) EURO-CORDEX RCMs. In the near future (2020-2049), heat waves are projected to be nearly twice as frequent in comparison to the modelled historical period, and the increase is even larger for severe heat waves. Uncertainty originates mainly from the selection of RCMs and GCMs because the increase is similar for all concentration scenarios. For the late twenty-first century (2070-2099), a substantial increase in heat wave frequencies is projected, the magnitude of which depends mainly upon concentration scenario. Three to four heat waves per summer are projected in this period (compared to less than one in the recent climate), and severe heat waves are likely to become a regular phenomenon. This increment is primarily driven by a positive shift of temperature distribution, but changes in its scale and enhanced temporal autocorrelation of temperature also contribute to the projected increase in heat wave frequencies.

  17. Method and device for microwave sintering large ceramic articles

    DOEpatents

    Kimrey, Jr., Harold D.

    1990-01-01

    A microwave sintering system and method are provided for extremely uniform sintering of large and/or irregular shaped ceramic articles at microwave frequencies of at least 28 GHz in the hundreds of kilowatts power range in an untuned cavity. A 28 GHz, 200 kw gyrotron with variable power output is used as the microwave source connected to an untuned microwave cavity formed of an electrically conductive housing through an overmoded waveguide arrangement which acts in conjunction with a mode promoter within the cavity to achieve unexpected field uniformity. The part to be sintered is placed in the cavity and supported on a removable high temperature table in a central location within the cavity. The part is surrounded by a microwave transparent bulk insulating material to reduce thermal heat loss at the part surfaces and maintain more uniform temperature. The cavity may be operated at a high vacuum to aid in preventing arcing. The system allows controlled increased heating rates of greater than 200.degree. C./min to provide rapid heating of a ceramic part to a selected sintering temperature where it is maintained by regulating the microwave power applied to the part. As a result of rapid heating, the extent of non-isothermal processes such as segregation of impurities to the grain boundaries are minimized and exaggerated grain growth is reduced, thereby strengthening the mechanical properties of the ceramic part being sintered.

  18. Spatial analysis of climate factors used to determine suitability of greenhouse production in Turkey

    NASA Astrophysics Data System (ADS)

    Cemek, Bilal; Güler, Mustafa; Arslan, Hakan

    2017-04-01

    This study aimed to identify the most suitable growing periods for greenhouse production in Turkey in order to make valuable contribution to economic viability. Data collected from the meteorological databases of 81 provinces was used to determine periodic climatological requirements of greenhouses in terms of cooling, heating, natural ventilation, and lighting. Spatial distributions of mean daily outside temperatures and greenhouse heating requirements were derived using ordinary co-kriging (OCK) supported by Geographical Information System (GIS). Mean monthly temperatures throughout the country were found to decrease below 12 °C in January, February, March, and December, indicating heating requirements, whereas temperatures in 94.46 % of the country rose above 22 °C in July, indicating cooling requirements. Artificial lighting is not a requirement in Turkey except for November, December, and January. The Mediterranean, Aegean, Marmara, and Black Sea Regions are more advantageous than the Central, East, and Southeast Anatolia Regions in terms of greenhouse production because the Mediterranean and Aegean Regions are more advantageous in terms of heating, and the Black Sea Region is more advantageous in terms of cooling. Results of our study indicated that greenhouse cultivation of winter vegetables is possible in certain areas in the north of the country. Moreover, greenhouses could alternatively be used for drying fruits and vegetables during the summer period which requires uneconomical cooling systems due to high temperatures in the Mediterranean and Southeastern Anatolian Regions.

  19. Evaluation of sodium benzoate and licorice (Glycyrrhiza glabra) root extract as heat-sensitizing additives against Escherichia coli O157:H7 in mildly heated young coconut liquid endosperm.

    PubMed

    Gabriel, A A; Salazar, S K P

    2014-08-01

    This study evaluated the use of sodium benzoate (SB) and licorice root extract (LRE) as heat-sensitizing additives against Escherichia coli O157:H7 in mildly heated young coconut liquid endosperm. Consumer acceptance scoring showed that maximum permissible supplementation (MPS) levels for SB and LRE were at 300 and 250 ppm, respectively. The MPS values were considered in the generation of a 2-factor rotatable central composite design for the tested SB and LRE concentration combinations. Liquid endosperm with various SB and LRE supplementation combinations was inoculated with E. coli O157:H7 and heated to 55°C. The susceptibility of the cells towards heating was expressed in terms of the decimal reduction time (D55 ). Response surface analysis showed that only the individual linear effect of benzoate significantly influenced D55 value, where increasing supplementation level resulted in increasing susceptibility. The results reported could serve as baseline information in further investigating other additives that could be used as heat-sensitizing agents against pathogens in heat-labile food systems. Fruit juice products have been linked to outbreaks of microbial infection, where unpasteurized products were proven vectors of diseases. Processors often opt not to apply heat process to juice products as the preservation technique often compromises the sensorial quality. This work evaluated two common additives for their heat-sensitizing effects against E. coli O157:H7 in coconut liquid endosperm, the results of which may serve as baseline information to small- and medium-scale processors, and researchers in the establishment of mild heat process schedule for the test commodity and other similar products. © 2014 The Society for Applied Microbiology.

  20. Heat wave over India during summer 2015: an assessment of real time extended range forecast

    NASA Astrophysics Data System (ADS)

    Pattanaik, D. R.; Mohapatra, M.; Srivastava, A. K.; Kumar, Arun

    2017-08-01

    Hot winds are the marked feature of summer season in India during late spring preceding the climatological onset of the monsoon season in June. Some years the conditions becomes very vulnerable with the maximum temperature ( T max) exceeding 45 °C for many days over parts of north-western, eastern coastal states of India and Indo-Gangetic plain. During summer of 2015 (late May to early June) eastern coastal states, central and northwestern parts of India experienced severe heat wave conditions leading to loss of thousands of human life in extreme high temperature conditions. It is not only the loss of human life but also the animals and birds were very vulnerable to this extreme heat wave conditions. In this study, an attempt is made to assess the performance of real time extended range forecast (forecast up to 3 weeks) of this scorching T max based on the NCEP's Climate Forecast System (CFS) latest version coupled model (CFSv2). The heat wave condition was very severe during the week from 22 to 28 May with subsequent week from 29 May to 4 June also witnessed high T max over many parts of central India including eastern coastal states of India. The 8 ensemble members of operational CFSv2 model are used once in a week to prepare the weekly bias corrected deterministic (ensemble mean) T max forecast for 3 weeks valid from Friday to Thursday coinciding with the heat wave periods of 2015. Using the 8 ensemble members separately and the CFSv2 corresponding hindcast climatology the probability of above and below normal T max is also prepared for the same 3 weeks. The real time deterministic and probabilistic forecasts did indicate impending heat wave over many parts of India during late May and early June of 2015 associated with strong northwesterly wind over main land mass of India, delaying the sea breeze, leading to heat waves over eastern coastal regions of India. Thus, the capability of coupled model in providing early warning of such killer heat wave can be very useful to the disaster managers to take appropriate actions to minimize the loss of life and property due to such high T max.

  1. Seasonal meningoencephalitis in Holstein cattle caused by Naegleria fowleri.

    PubMed

    Daft, Barbara M; Visvesvara, Govinda S; Read, Deryck H; Kinde, Hailu; Uzal, Francisco A; Manzer, Michael D

    2005-11-01

    Primary amoebic meningoencephalitis is a fulminant infection of the human central nervous system caused by Naegleria fowleri, a free-living amoeba that thrives in artificially or naturally heated water. The infection usually is acquired while bathing or swimming in such waters. The portal of entry is the olfactory neuroepithelium. This report describes fatal meningoencephalitis caused by N. fowleri in Holstein cattle that consumed untreated surface water in an area of California where summer temperatures at times exceed 42 degrees C. In the summers of 1998 and 1999, severe multifocal necrosuppurative hemorrhagic meningoencephalitis was observed in brain samples from nine 10-20-month-old heifers with clinical histories of acute central nervous system disease. Olfactory lobes and cerebella were most severely affected. Lesions were also evident in periventricular and submeningeal neuropil as well as olfactory nerves. Naegleria fowleri was demonstrated by immunohistochemistry in brain and olfactory nerve lesions and was isolated from one brain. Even though cultures of drinking water did not yield N. fowleri, drinking water was the likely source of the amoeba. The disease in cattle closely resembles primary amoebic meningoencephalitis in humans. Naegleria meningoencephalitis should be included among differential diagnoses of central nervous system disease in cattle during the summer season in areas with high ambient temperatures.

  2. Electromagnetic tornadoes in space

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

    Chang, T.; Crew, G.B.; Retterer, J.M.

    1988-01-01

    The exotic phenomenon of energetic-ion conic formation by plasma waves in the magnetosphere is considered. Two particular transverse heating mechanisms are reviewed in detail; lower-hybrid energization of ions in the boundary layer of the plasma sheet and electromagnetic ion cyclotron resonance heating in the central region of the plasma sheet. Mean particle calculations, plasma simulations and analytical treatments of the heating processes are described.

  3. Engine Air Intake Manifold Having Built In Intercooler

    DOEpatents

    Freese, V, Charles E.

    2000-09-12

    A turbocharged V type engine can be equipped with an exhaust gas recirculation cooler integrated into the intake manifold, so as to achieve efficiency, cost reductions and space economization improvements. The cooler can take the form of a tube-shell heat exchanger that utilizes a cylindrical chamber in the air intake manifold as the heat exchanger housing. The intake manifold depends into the central space formed by the two banks of cylinders on the V type engine, such that the central space is effectively utilized for containing the manifold and cooler.

  4. Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City.

    PubMed

    Dang, Tran Ngoc; Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T; Honda, Yasushi

    2018-04-01

    To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. The temperature-mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted.

  5. [Effect of heat shock on courtship behavior, sound production, and learning in comparison with the brain content of LIMK1 in Drosophila melanogaster males with altered structure of the LIMK1 gene].

    PubMed

    Nikitina, E A; Kaminskaya, A N; Molotkov, D A; Popov, A V; Savvateeva-Popova, E V

    2014-01-01

    In this paper we present results of a comprehensive analysis of the effect of heat shock at different stages of ontogenesis (adult stage, development of the mushroom bodies and the central complex) on courtship behavior (latency, duration and efficacy of courtship), sound production (pulse interval, dispersion of interpulse interval, the percentage of distorted pulses, the mean duration of the pulse parcels), learning and memory formation compared with the content of isoforms LIMK1 in Drosophila melanogaster male with altered structure of the limk1 gene. The heat shock is shown to affect the behavior parameters and LIMK1 content in analyzed strains of Drosophila. The most pronounced effect of the heat shock was observed at the stage of development of the central complex (CC). Heat shock at CC and adult restores the ability of learning and memory formation in the mutant strain agn(ts3), which normally is not able to learn and form memory. Correlations between changes of content of isoforms LIMK1 and behavioral parameters due to heat shock have not been established.

  6. Green Space and Deaths Attributable to the Urban Heat Island Effect in Ho Chi Minh City

    PubMed Central

    Van, Doan Quang; Kusaka, Hiroyuki; Seposo, Xerxes T.; Honda, Yasushi

    2018-01-01

    Objectives. To quantify heat-related deaths in Ho Chi Minh City, Vietnam, caused by the urban heat island (UHI) and explore factors that may alleviate the impact of UHIs. Methods. We estimated district-specific meteorological conditions from 2010 to 2013 using the dynamic downscaling model and calculated the attributable fraction and number of mortalities resulting from the total, extreme, and mild heat in each district. The difference in attributable fraction of total heat between the central and outer districts was classified as the attributable fraction resulting from the UHI. The association among attributable fraction, attributable number with a green space, population density, and budget revenue of each district was then explored. Results. The temperature–mortality relationship between the central and outer areas was almost identical. The attributable fraction resulting from the UHI was 0.42%, which was contributed by the difference in temperature distribution between the 2 areas. Every 1-square-kilometer increase in green space per 1000 people can prevent 7.4 deaths caused by heat. Conclusions. Green space can alleviate the impacts of UHIs, although future studies conducting a heath economic evaluation of tree planting are warranted. PMID:29072938

  7. Observations of electron heating during 28 GHz microwave power application in proto-MPEX

    DOE PAGES

    Biewer, Theodore M.; Bigelow, Tim S.; Caneses Marin, Juan F.; ...

    2018-02-01

    The Prototype Material Plasma Exposure Experiment at the Oak Ridge National Laboratory utilizes a variety of power systems to generate and deliver a high heat flux plasma onto the surface of material targets. In the experiments described here, a deuterium plasma is produced via a ~100 kW, 13.56 MHz RF helicon source, to which ~20 kW of 28 GHz microwave power is applied. The electron density and temperature profiles are measured using a Thomson scattering (TS) diagnostic, and indicate that the electron density is centrally peaked. In the core of the plasma column, the electron density is higher than themore » cut-off density (~0.9 × 1019 m -3) for the launched mixture of X- and O-mode electron cyclotron heating waves to propagate. TS measurements indicate electron temperature increases from ~5 eV to ~20 eV during 28 GHz power application when the neutral deuterium pressure is reduced below 0.13 Pa (~1 mTorr.).« less

  8. Observations of electron heating during 28 GHz microwave power application in proto-MPEX

    NASA Astrophysics Data System (ADS)

    Biewer, T. M.; Bigelow, T. S.; Caneses, J. F.; Diem, S. J.; Green, D. L.; Kafle, N.; Rapp, J.; Proto-MPEX Team

    2018-02-01

    The Prototype Material Plasma Exposure Experiment at the Oak Ridge National Laboratory utilizes a variety of power systems to generate and deliver a high heat flux plasma onto the surface of material targets. In the experiments described here, a deuterium plasma is produced via a ˜100 kW, 13.56 MHz RF helicon source, to which ˜20 kW of 28 GHz microwave power is applied. The electron density and temperature profiles are measured using a Thomson scattering (TS) diagnostic, and indicate that the electron density is centrally peaked. In the core of the plasma column, the electron density is higher than the cut-off density (˜0.9 × 1019 m-3) for the launched mixture of X- and O-mode electron cyclotron heating waves to propagate. TS measurements indicate electron temperature increases from ˜5 eV to ˜20 eV during 28 GHz power application when the neutral deuterium pressure is reduced below 0.13 Pa (˜1 mTorr.).

  9. Using thermal stress to model aspects of disease states.

    PubMed

    Wilson, Thad E; Klabunde, Richard E; Monahan, Kevin D

    2014-07-01

    Exposure to acute heat or cold stress elicits numerous physiological responses aimed at maintaining body temperatures. Interestingly, many of the physiological responses, mediated by the cardiovascular and autonomic nervous systems, resemble aspects of, or responses to, certain disease states. The purpose of this Perspective is to highlight some of these areas in order to explore how they may help us better understand the pathophysiology underlying aspects of certain disease states. The benefits of using this human thermal stress approach are that (1) no adjustments for inherent comparative differences in animals are needed, (2) non-medicated healthy humans with no underlying co-morbidities can be studied in place of complex patients, and (3) more mechanistic perturbations can be safely employed without endangering potentially vulnerable populations. Cold stress can be used to induce stable elevations in blood pressure. Cold stress may also be used to model conditions where increases in myocardial oxygen demand are not met by anticipated increases in coronary blood flow, as occurs in older adults. Lower-body negative pressure has the capacity to model aspects of shock, and the further addition of heat stress improves and expands this model because passive-heat exposure lowers systemic vascular resistance at a time when central blood volume and left-ventricular filling pressure are reduced. Heat stress can model aspects of heat syncope and orthostatic intolerance as heat stress decreases cerebral blood flow and alters the Frank-Starling mechanism resulting in larger decreases in stroke volume for a given change in left-ventricular filling pressure. Combined, thermal perturbations may provide in vivo paradigms that can be employed to gain insights into pathophysiological aspects of certain disease states. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. The Effect of Multigrid Parameters in a 3D Heat Diffusion Equation

    NASA Astrophysics Data System (ADS)

    Oliveira, F. De; Franco, S. R.; Pinto, M. A. Villela

    2018-02-01

    The aim of this paper is to reduce the necessary CPU time to solve the three-dimensional heat diffusion equation using Dirichlet boundary conditions. The finite difference method (FDM) is used to discretize the differential equations with a second-order accuracy central difference scheme (CDS). The algebraic equations systems are solved using the lexicographical and red-black Gauss-Seidel methods, associated with the geometric multigrid method with a correction scheme (CS) and V-cycle. Comparisons are made between two types of restriction: injection and full weighting. The used prolongation process is the trilinear interpolation. This work is concerned with the study of the influence of the smoothing value (v), number of mesh levels (L) and number of unknowns (N) on the CPU time, as well as the analysis of algorithm complexity.

  11. Enrichment of Secondary Wastewater Sludge for Production of Hydrogen from Crude Glycerol and Comparative Evaluation of Mono-, Co- and Mixed-Culture Systems

    PubMed Central

    Pachapur, Vinayak Laxman; Kutty, Prianka; Brar, Satinder Kaur; Ramirez, Antonio Avalos

    2016-01-01

    Anaerobic digestion using mixed-culture with broader choice of pretreatments for hydrogen (H2) production was investigated. Pretreatment of wastewater sludge by five methods, such as heat, acid, base, microwave and chloroform was conducted using crude glycerol (CG) as substrate. Results for heat treatment (100 °C for 15 min) showed the highest H2 production across the pretreatment methods with 15.18 ± 0.26 mmol/L of medium at 30 °C in absence of complex media and nutrient solution. The heat-pretreated inoculum eliminated H2 consuming bacteria and produced twice as much as H2 as compared to other pretreatment methods. The fermentation conditions, such as CG concentration (1.23 to 24 g/L), percentage of inoculum size (InS) (1.23% to 24% v/v) along with initial pH (2.98 to 8.02) was tested using central composite design (CCD) with H2 production as response parameter. The maximum H2 production of 29.43 ± 0.71 mmol/L obtained at optimum conditions of 20 g/L CG, 20% InS and pH 7. Symbiotic correlation of pH over CG and InS had a significant (p-value: 0.0011) contribution to H2 production. The mixed-culture possessed better natural acclimatization activity for degrading CG, at substrate inhibition concentration and provided efficient inoculum conditions in comparison to mono- and co-culture systems. The heat pretreatment step used across mixed-culture system is simple, cheap and industrially applicable in comparison to mono-/co-culture systems for H2 production. PMID:26771607

  12. Environments of Long-Lived Mesoscale Convective Systems Over the Central United States in Convection Permitting Climate Simulations: Long-Lived Mesoscale Convective Systems

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

    Yang, Qing; Houze, Robert A.; Leung, L. Ruby

    Continental-scale convection-permitting simulations of the warm seasons of 2011 and 2012 reproduce realistic structure and frequency distribution of lifetime and event mean precipitation of mesoscale convective systems (MCSs) over the central United States. Analysis is performed to determine the environmental conditions conducive to generating the longest-lived MCSs and their subsequent interactions. The simulations show that MCSs systematically form over the Great Plains ahead of a trough in the westerlies in combination with an enhanced low-level jet from the Gulf of Mexico. These environmental properties at the time of storm initiation are most prominent for the MCSs that persist for themore » longest times. Systems reaching 9 h or more in lifetime exhibit feedback to the environment conditions through diabatic heating in the MCS stratiform regions. As a result, the parent synoptic-scale wave is strengthened as a divergent perturbation develops over the MCS at high levels, while a cyclonic circulation perturbation develops in the midlevels of the trough, where the vertical gradient of heating in the MCS region is maximized. The quasi-balanced mesoscale vortex helps to maintain the MCS over a long period of time by feeding dry, cool air into the environment at the rear of the MCS region, so that the MCS can draw in air that increases the evaporative cooling that helps maintain the MCS. At lower levels the south-southeasterly jet of warm moist air from the Gulf is enhanced in the presence of the synoptic-scale wave. That moisture supply is essential to the continued redevelopment of the MCS.« less

  13. Evaluation of major heat waves' mechanisms in EURO-CORDEX RCMs over Central Europe

    NASA Astrophysics Data System (ADS)

    Lhotka, Ondřej; Kyselý, Jan; Plavcová, Eva

    2018-06-01

    The main aim of the study is to evaluate the capability of EURO-CORDEX regional climate models (RCMs) to simulate major heat waves in Central Europe and their associated meteorological factors. Three reference major heat waves (1994, 2006, and 2015) were identified in the E-OBS gridded data set, based on their temperature characteristics, length and spatial extent. Atmospheric circulation, precipitation, net shortwave radiation, and evaporative fraction anomalies during these events were assessed using the ERA-Interim reanalysis. The analogous major heat waves and their links to the aforementioned factors were analysed in an ensemble of EURO-CORDEX RCMs driven by various global climate models in the 1970-2016 period. All three reference major heat waves were associated with favourable circulation conditions, precipitation deficit, reduced evaporative fraction and increased net shortwave radiation. This joint contribution of large-scale circulation and land-atmosphere interactions is simulated with difficulties in majority of the RCMs, which affects the magnitude of modelled major heat waves. In some cases, the seemingly good reproduction of major heat waves' magnitude is erroneously achieved through extremely favourable circulation conditions compensated by a substantial surplus of soil moisture or vice versa. These findings point to different driving mechanisms of major heat waves in some RCMs compared to observations, which should be taken into account when analysing and interpreting future projections of these events.

  14. In-field measurements of PCDD/F emissions from domestic heating appliances for solid fuels.

    PubMed

    Hübner, C; Boos, R; Prey, T

    2005-01-01

    Within this project the emissions into the atmosphere of polychlorinated dibenzo-p-dioxins and -furans (PCDD/F) of 30 domestic heating appliances in Austrian households were tested. The appliances were single stoves (kitchen stove, continuous burning stove and tiled stove) and central heating boilers for solid fuels up to a nominal heat input of 50 kW. A main objective of this survey was to determine the PCDD/F emissions of domestic heating units under routine conditions. Therefore, the habitual combustion conditions used by the operators were not influenced. The original fuels and lightning supports were used and the operation of the units was carried out by the householders according to their usual practice. The data obtained were used to calculate in-field PCDD/F-emission factors. Most of the appliances have shown PCDD/F emissions within a concentration range of 0.01-0.3 ng TEQ/MJ. Modern fan-assisted wood heating boilers with afterburning and units for continuously burning of wood chips and wood pellets had the lowest emissions. High emissions were caused by unsuitable heating habits such as combustion of wastes and inappropriate operation of the appliances. There were only small differences between single stoves and central heating boilers or between wood and coal-fired appliances. The emission factors calculated are higher than those cited in literature, which are mainly derived from trials on test stands under laboratory conditions.

  15. On the Dynamics of Austral Heat Waves

    NASA Astrophysics Data System (ADS)

    Risbey, James S.; O'Kane, Terence J.; Monselesan, Didier P.; Franzke, Christian L. E.; Horenko, Illia

    2018-01-01

    This work examines summer heat wave events in four different regions of Australia (southwest, central, southeast, and northeast) to assess similarities and differences in the circulations that precede, accompany, and follow the heat wave events. A series of circulation composites are constructed for days from 10 days prior to 5 days following onset of each heat wave event. The composites of geopotential height anomalies and wave activity flux vectors show that heat waves in southwest and southeast Australia are preceded by coherent wave train structures in the Indian Ocean region, accompanied by blocking in the Australian region (as an amplified node of the wave train structure), and followed by coherent responses of wave train patterns in the Pacific and South America regions. The heat wave blocking high is maintained by convergence of wave activity in a well-defined wave channel. The concentration of wave activity in the block is aided by the formation of a subtropical jet branch and wave barrier on the equatorward side of the block. Heat waves in central and northeast Australia show similar wave train life cycle responses, but with a proximate ridge in the midtroposphere and a trough in the nearby waveguide region. Heat waves in Australia can be viewed as an element of successive expression of the planetary waveguide modes in the Southern Hemisphere and serve as signifiers of organized, active phases of these modes.

  16. Central dopaminergic neurotransmission plays an important role in thermoregulation and performance during endurance exercise.

    PubMed

    Zheng, Xinyan; Hasegawa, Hiroshi

    2016-10-01

    Dopamine (DA) has been widely investigated for its potential role in determining exercise performance. It was originally thought that DA's ergogenic effect was by mediating psychological responses. Recently, some studies have also suggested that DA may regulate physiological responses, such as thermoregulation. Hyperthermia has been demonstrated as an important limiting factor during endurance exercise. DA is prominent in the thermoregulatory centre, and changes in DA concentration have been shown to affect core temperature regulation during exercise. Some studies have proposed that DA or DA/noradrenaline (NA) reuptake inhibitors can improve exercise performance, despite hyperthermia during exercise in the heat. DA/NA reuptake inhibitors also increase catecholamine release in the thermoregulatory centre. Intracerebroventricularly injected DA has been shown to improve exercise performance through inhibiting hyperthermia-induced fatigue, even at normal ambient temperatures. Further, caffeine has been reported to increase DA release in the thermoregulatory centre and improves endurance exercise performance despite increased core body temperature. Taken together, DA has been shown to have ergogenic effects and increase heat storage and hyperthermia tolerance. The mechanisms underlying these effects seem to involve limiting/overriding the inhibitory signals from the central nervous system that result in cessation of exercise due to hyperthermia.

  17. Different mechanisms of magnetisation recorded in experimental fires: Archaeomagnetic implications

    NASA Astrophysics Data System (ADS)

    Carrancho, Á.; Villalaín, J. J.

    2011-12-01

    We present here the archaeomagnetic and rock-magnetic results obtained from the experimental recreation of prehistoric fires on a clayish soil substratum. By using a system of thermocouples that allows the control of temperatures and heat penetration with depth, the magneto-mineralogical transformations as well as the ability to acquire magnetic remanences are studied. A detailed set of rock-magnetic analyses - carried out both on surface and depth with a millimetre scale resolution- shows the creation of post-burn magnetite over the entire surface of the hearth, thus promoting a distinguishable magnetic enhancement. On the basis of a detailed control of temperatures, interesting differences between areas (centre vs. periphery) were observed and two different mechanisms of magnetisation have been recorded. The central area which exceeded 600 °C acquired a thermal remanent magnetisation (TRM) and the periphery, which was heated up to 300 °C, recorded a thermo-chemical (TCRM) remanent magnetisation. The most noticeable mineralogical changes are focused to the first centimetre of the central area, where single-domain magnetite has been created. The implications of these results for archaeomagnetic and palaeointensity studies as well as their utility for the detection of fire in archaeological sites are discussed.

  18. Wastewater recycling and heat reclamation project: Red Lion Central Laundry, Portland, Oregon

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

    Garlick, T.F.; Halverson, M.A.; Ledbetter, M.R.

    1997-06-01

    This report discusses water, energy, and cost savings that can be achieved in a commercial laundry through the use of a wastewater recycling and heat recovery system. Cost savings are achieved through reductions in water use, reduction in sewage charges (typically based on water use), reductions in water heating energy, and potential reductions in water treatment chemicals because the recycled water has already been treated with soaps and conditioners. A recovery system saves water by recycling wash water that would normally be dumped into the city sewage system. Recycling the wash water produces considerable energy savings because the recycled watermore » has a higher temperature than fresh water. As a result, a hot water heater consumes less energy to heat the recycled water. The demonstration project discussed in this report was based in a large commercial laundry in Portland, Oregon. The laundry serves a large hotel/motel chain and processes an average of 25,000 pounds of laundry per day. A wastewater recovery system using a membrane microfiltration unit (MFU) was installed in the laundry in September 1995. Time series data of the water and energy consumption of the laundry were taken before and after installation of the MFU. Energy savings were measured by performing a thermal energy balance around the washing machines. Water savings were calculated by metering volumetric flow rates. After a period of approximately five months, the MFU has achieved final results of 52 percent savings in water consumption and 44 percent savings in energy to heat water. This five-month period represents a learning curve during which several small technical improvements were made to the MFU and laundry staff adjusted laundry operations to maximize the benefits of the MFU. An economic analysis discusses the impact of capital investment, daily consumption, and local utility rates on the payback period.« less

  19. Heating and Cooling Master Plan for Fort Bragg, NC, Fiscal Years 2005 to 2030

    DTIC Science & Technology

    2009-02-01

    Pacific Northwest National Labora- tory ( PNNL ) performed an energy use analysis on these buildings in 2005. These buildings are located in 33 specific...electrical equipment the electrical use is provided in the PNNL analysis .* The central chilled water system energy use is reported in cooling chilled...February 2009 C on st ru ct io n E n gi n ee ri n g R es ea rc h L ab or at or y Approved for public release; distribution is unlimited

  20. Apparatus for precise regulation and chilling of water temperatures in laboratory studies

    USGS Publications Warehouse

    Burger, C.; ,

    1991-01-01

    Laboratory simulation of water temperature regimes that occur in subarctic rivers through winter necessitates the ability to maintain near-freezing conditions. A heat-exchangeing apparatus is described that provided a convenient means of simulating the range of temperatures (0.5-12 degrees C) that incubating eggs of salmon (Oncorhynchus spp.) typically experience in south-central Alaska watersheds. The system was reliable, easily maintained precise temperatures at our coldest test levels, and was used over several years with few mechanical complications.

  1. Hyperthermia combined with ethanol administration induces c-fos expression in the central amygdaloid nucleus of the mouse brain. A possible mechanism of heatstroke under the influence of ethanol intake.

    PubMed

    Kibayashi, Kazuhiko; Nakao, Ken-ichiro; Shojo, Hideki

    2009-09-01

    Heatstroke is defined as a core body temperature that rises above 40.6 degrees C and is accompanied by mental status abnormalities such as delirium, convulsions, or coma resulting from exposure to environmental heat. There is fairly wide agreement that ethanol intake is a predisposing factor in heatstroke. This study was performed to identify the brain changes induced by heatstroke, using a mouse hyperthermia model with and without preceding ethanol administration. Exposure to heat of 42 degrees C until the core temperature reached to 43 degrees C followed by exposure to 37 degrees C for 15 min decreased the levels of partial pressures of O(2) in blood. Preceding ethanol administration and heat exposure induced hypotension, severe metabolic acidosis and respiratory failure, and, accordingly, produced heatstroke. Immunohistochemistry of the brains showed that preceding ethanol administration increased the number of c-fos-immunoreactive neurons, as a marker of neuronal activation, in the central amygdaloid nucleus, which is involved in thermoregulation. These results indicate that combined effects of ethanol and heat exposure induce heatstroke that is associated with activation of the central amygdaloid nucleus, implicating the pathophysiology and mechanisms of heatstroke under the influence of ethanol intake.

  2. DNB heat flux in forced convection of liquid hydrogen for a wire set in central axis of vertically mounted flow channel

    NASA Astrophysics Data System (ADS)

    Matsumoto, T.; Shirai, Y.; Shiotsu, M.; Fujita, K.; Kainuma, T.; Tatsumoto, H.; Naruo, Y.; Kobayashi, H.; Nonaka, S.; Inatani, Y.

    2017-12-01

    Liquid hydrogen has excellent physical properties, high latent heat and low viscosity of liquid, as a coolant for superconductors like MgB2. The knowledge of Departure from Nucleate Boiling (DNB) heat flux of liquid hydrogen is necessary for designing and cooling analysis of high critical temperature superconducting devices. In this paper, DNB heat fluxes of liquid hydrogen were measured under saturated and subcooled conditions at absolute pressures of 400, 700 and 1100 kPa for various flow velocities. Two wire test heaters made by Pt-Co alloy with the length of 200 mm and the diameter of 0.7 mm were used. And these round heaters were set in central axis of a flow channel made of Fiber Reinforced Plastic (FRP) with inner diameters of 8 mm and 12 mm. These test bodies were vertically mounted and liquid hydrogen flowed upward through the channel. From these experimental values, the correlations of DNB heat flux under saturated and subcooled conditions are presented in this paper.

  3. Lunar in-core thermionic nuclear reactor power system conceptual design

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Schmitz, Paul C.; Gallup, Donald R.

    1991-01-01

    This paper presents a conceptual design of a lunar in-core thermionic reactor power system. The concept consists of a thermionic reactor located in a lunar excavation with surface mounted waste heat radiators. The system was integrated with a proposed lunar base concept representative of recent NASA Space Exploration Initiative studies. The reference mission is a permanently-inhabited lunar base requiring a 550 kWe, 7 year life central power station. Performance parameters and assumptions were based on the Thermionic Fuel Element (TFE) Verification Program. Five design cases were analyzed ranging from conservative to advanced. The cases were selected to provide sensitivity effects on the achievement of TFE program goals.

  4. Preliminary design of the Space Station internal thermal control system

    NASA Technical Reports Server (NTRS)

    Herrin, Mark T.; Patterson, David W.; Turner, Larry D.

    1987-01-01

    The baseline preliminary design configuration of the Internal Thermal Control system (ITCS) of the U.S. Space Station pressurized elements (i.e., the Habitation and U.S. Laboratory modules, pressurized logistics carrier, and resources nodes) is defined. The ITCS is composed of both active and passive components. The subsystems which comprise the ITCS are identified and their functional descriptions are provided. The significant trades and analyses, which were performed during Phase B (i.e., the preliminary design phase) that resulted in the design described herein, are discussed. The ITCS interfaces with the station's central Heat Rejection and Transport System (HRTS), other systems, and externally attached pressurized payloads are described. Requirements on the ITCS with regard to redundancy and experiment support are also addressed.

  5. Predicting the Impacts of Climate Change on Central American Agriculture

    NASA Astrophysics Data System (ADS)

    Winter, J. M.; Ruane, A. C.; Rosenzweig, C.

    2011-12-01

    Agriculture is a vital component of Central America's economy. Poor crop yields and harvest reliability can produce food insecurity, malnutrition, and conflict. Regional climate models (RCMs) and agricultural models have the potential to greatly enhance the efficiency of Central American agriculture and water resources management under both current and future climates. A series of numerical experiments was conducted using Regional Climate Model Version 3 (RegCM3) and the Weather Research and Forecasting Model (WRF) to evaluate the ability of RCMs to reproduce the current climate of Central America and assess changes in temperature and precipitation under multiple future climate scenarios. Control simulations were thoroughly compared to a variety of observational datasets, including local weather station data, gridded meteorological data, and high-resolution satellite-based precipitation products. Future climate simulations were analyzed for both mean shifts in climate and changes in climate variability, including extreme events (droughts, heat waves, floods). To explore the impacts of changing climate on maize, bean, and rice yields in Central America, RCM output was used to force the Decision Support System for Agrotechnology Transfer Model (DSSAT). These results were synthesized to create climate change impacts predictions for Central American agriculture that explicitly account for evolving distributions of precipitation and temperature extremes.

  6. Peristaltic flow of Powell-Eyring fluid in curved channel with heat transfer: A useful application in biomedicine.

    PubMed

    Hina, S; Mustafa, M; Hayat, T; Alsaedi, A

    2016-10-01

    In this work, we explore the heat transfer characteristics in the peristaltic transport of Powell-Eyring fluid inside a curved channel with complaint walls. The study has motivation toward the understanding of blood flow in microcirculatory system. Formulation is developed in the existence of velocity slip and temperature jump conditions. Perturbation approach has been utilized to present series expressions of axial velocity and temperature distributions. Streamlines are prepared to analyze the interesting phenomenon of trapping. Moreover, the plots of heat transfer coefficient for a broad range of embedded parameters are presented and discussed. The results indicate that slip effects substantially influence the velocity and temperature distributions. Axial flow accelerates when slip parameter is incremented. Temperature rises and wall heat flux grows when viscous dissipation effect is strengthened. In contrast to the planar channels, here velocity and temperature functions do not exhibit symmetry with respect to the central line. In addition, bolus size and its shape are different in upper and lower portions of the channel. Heat transfer coefficient enlarges when the curvature effects are reduced. The behaviors of wall tension and wall mass parameters on the profiles are qualitatively similar. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  7. Identifying student difficulties with entropy, heat engines, and the Carnot cycle

    NASA Astrophysics Data System (ADS)

    Smith, Trevor I.; Christensen, Warren M.; Mountcastle, Donald B.; Thompson, John R.

    2015-12-01

    [This paper is part of the Focused Collection on Upper Division Physics Courses.] We report on several specific student difficulties regarding the second law of thermodynamics in the context of heat engines within upper-division undergraduate thermal physics courses. Data come from ungraded written surveys, graded homework assignments, and videotaped classroom observations of tutorial activities. Written data show that students in these courses do not clearly articulate the connection between the Carnot cycle and the second law after lecture instruction. This result is consistent both within and across student populations. Observation data provide evidence for myriad difficulties related to entropy and heat engines, including students' struggles in reasoning about situations that are physically impossible and failures to differentiate between differential and net changes of state properties of a system. Results herein may be seen as the application of previously documented difficulties in the context of heat engines, but others are novel and emphasize the subtle and complex nature of cyclic processes and heat engines, which are central to the teaching and learning of thermodynamics and its applications. Moreover, the sophistication of these difficulties is indicative of the more advanced thinking required of students at the upper division, whose developing knowledge and understanding give rise to questions and struggles that are inaccessible to novices.

  8. Central neural control of thermoregulation and brown adipose tissue

    PubMed Central

    Morrison, Shaun F.

    2016-01-01

    Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation. PMID:26924538

  9. Central neural control of thermoregulation and brown adipose tissue.

    PubMed

    Morrison, Shaun F

    2016-04-01

    Central neural circuits orchestrate the homeostatic repertoire that maintains body temperature during environmental temperature challenges and alters body temperature during the inflammatory response. This review summarizes the experimental underpinnings of our current model of the CNS pathways controlling the principal thermoeffectors for body temperature regulation: cutaneous vasoconstriction controlling heat loss, and shivering and brown adipose tissue for thermogenesis. The activation of these effectors is regulated by parallel but distinct, effector-specific, core efferent pathways within the CNS that share a common peripheral thermal sensory input. Via the lateral parabrachial nucleus, skin thermal afferent input reaches the hypothalamic preoptic area to inhibit warm-sensitive, inhibitory output neurons which control heat production by inhibiting thermogenesis-promoting neurons in the dorsomedial hypothalamus that project to thermogenesis-controlling premotor neurons in the rostral ventromedial medulla, including the raphe pallidus, that descend to provide the excitation of spinal circuits necessary to drive thermogenic thermal effectors. A distinct population of warm-sensitive preoptic neurons controls heat loss through an inhibitory input to raphe pallidus sympathetic premotor neurons controlling cutaneous vasoconstriction. The model proposed for central thermoregulatory control provides a useful platform for further understanding of the functional organization of central thermoregulation and elucidating the hypothalamic circuitry and neurotransmitters involved in body temperature regulation. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Health and safety implications of alternative energy technologies. II. Solar

    NASA Astrophysics Data System (ADS)

    Etnier, E. L.; Watson, A. P.

    1981-09-01

    No energy technology is risk free when all aspects of its utilization are taken into account. Every energy technology has some attendant direct and indirect health and safety concerns. Solar technologies examined in this paper are wind, ocean thermal energy gradients, passive, photovoltaic, satellite power systems, low- and high-temperature collectors, and central power stations, as well as tidal power. For many of these technologies, insufficient historical data are available from which to assess the health risks and environmental impacts. However, their similarities to other projects make certain predictions possible. For example, anticipated problems in worker safety in constructing ocean thermal energy conversion systems will be similar to those associated with other large-scale construction projects, like deep-sea oil drilling platforms. Occupational hazards associated with photovoltaic plant operation would be those associated with normal electricity generation, although for workers involved in the actual production of photovoltaic materials, there is some concern for the toxic effects of the materials used, including silicon, cadmium, and gallium arsenide. Satellite power systems have several unique risks. These include the effects of long-term space travel for construction workers, effects on the ozone layer and the attendant risk of skin cancer in the general public, and the as-yet-undetermined effects of long-term, low-level microwave exposure. Hazards may arise from three sources in solar heating and cooling systems: water contamination from corrosion inhibitors, heat transfer fluids, and bactericides; collector over-heating, fires, and “out-gassing” and handling and disposal of system fluids and wastes. Similar concerns exist for solar thermal power systems. Even passive solar systems may increase indoor exposure levels to various air pollutants and toxic substances, eitherdirectly from the solar system itself or indirectly by trapping released pollutants from furnishings, building materials, and indoor combustion.

  11. Central circuitries for body temperature regulation and fever.

    PubMed

    Nakamura, Kazuhiro

    2011-11-01

    Body temperature regulation is a fundamental homeostatic function that is governed by the central nervous system in homeothermic animals, including humans. The central thermoregulatory system also functions for host defense from invading pathogens by elevating body core temperature, a response known as fever. Thermoregulation and fever involve a variety of involuntary effector responses, and this review summarizes the current understandings of the central circuitry mechanisms that underlie nonshivering thermogenesis in brown adipose tissue, shivering thermogenesis in skeletal muscles, thermoregulatory cardiac regulation, heat-loss regulation through cutaneous vasomotion, and ACTH release. To defend thermal homeostasis from environmental thermal challenges, feedforward thermosensory information on environmental temperature sensed by skin thermoreceptors ascends through the spinal cord and lateral parabrachial nucleus to the preoptic area (POA). The POA also receives feedback signals from local thermosensitive neurons, as well as pyrogenic signals of prostaglandin E(2) produced in response to infection. These afferent signals are integrated and affect the activity of GABAergic inhibitory projection neurons descending from the POA to the dorsomedial hypothalamus (DMH) or to the rostral medullary raphe region (rMR). Attenuation of the descending inhibition by cooling or pyrogenic signals leads to disinhibition of thermogenic neurons in the DMH and sympathetic and somatic premotor neurons in the rMR, which then drive spinal motor output mechanisms to elicit thermogenesis, tachycardia, and cutaneous vasoconstriction. Warming signals enhance the descending inhibition from the POA to inhibit the motor outputs, resulting in cutaneous vasodilation and inhibited thermogenesis. This central thermoregulatory mechanism also functions for metabolic regulation and stress-induced hyperthermia.

  12. Solidification processing of alloys using an applied electric field

    NASA Technical Reports Server (NTRS)

    Mckannan, Eugene C. (Inventor); Schmidt, Deborah D. (Inventor); Ahmed, Shaffiq (Inventor); Bond, Robert W. (Inventor)

    1990-01-01

    A method is provided for obtaining an alloy having an ordered microstructure which comprises the steps of heating the central portion of the alloy under uniform temperature so that it enters a liquid phase while the outer portions remain solid, applying a constant electric current through the alloy during the heating step, and solidifying the liquid central portion of the alloy by subjecting it to a temperature-gradient zone so that cooling occurs in a directional manner and at a given rate of speed while maintaining the application of the constant electric current through the alloy. The method of the present invention produces an alloy having superior characteristics such as reduced segregation. After subsequent precipitation by heat-treatment, the alloys produced by the present invention will have excellent strength and high-temperature resistance.

  13. Effect of intrathecal baclofen on evoked pain perception: an evoked potentials and quantitative thermal testing study.

    PubMed

    Kumru, H; Kofler, M; Flores, M C; Portell, E; Robles, V; Leon, N; Vidal, J

    2013-08-01

    Somatic antinociceptive effects of baclofen have been demonstrated in animal models. We hypothesized that if enhanced thermal or pain sensitivity is produced by loss of gamma-aminobutyric acid (GABA)-ergic tone in the central nervous system, spinal administration of GABA agonists might be predicted to be effective in thermal and/or pain perception changes and pain-related evoked potentials in candidates for intrathecal baclofen (ITB) treatment. Eleven patients with severe spinal cord injury (SCI) who suffered from severe spasticity were evaluated during a 50-μg ITB bolus test. Warm and heat pain thresholds, evoked heat pain perception, and contact heat-evoked potentials (CHEPs) were determined above SCI level from the right and left sides. Nine age- and gender-matched healthy volunteers undergoing repeat testing without any placebo injection served as control group. In patients, heat pain perception threshold increased, and evoked pain perception and amplitude of CHEPs decreased significantly after ITB bolus application in comparison with baseline (p < 0.005), with no change in warm perception threshold. In controls, no significant changes were observed in repeat testing over time. Our findings indicate that ITB modulates heat pain perception threshold, evoked heat pain perception and heat pain-related evoked potentials without inducing warm perception threshold changes in SCI patients. This phenomenon should be taken into account in the clinical evaluation and management of pain in patients receiving baclofen. © 2012 European Federation of International Association for the Study of Pain Chapters.

  14. Electron Bernstein Wave Emission Studies on the TJ-II Stellarator

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

    Caughman, John B; Fernandez, A.; Cappa, A.

    2009-01-01

    Electron Bernstein Wave (EBW) heating is important for high-beta plasma experiments and will be used for heating over-dense plasmas on TJ-II. TJ-II is a medium sized Heliac operating at CIEMAT in Madrid, whose plasmas are created and heated by ECH via two 300 kW gyrotrons at second harmonic X-mode (53.2 GHz), with additional heating provided by two neutral beam injectors. Theoretical work has shown that the most suitable scheme for launching EBWs in TJ-II is O-X-B mode conversion, which has acceptable heating efficiency for central densities above 1.2 x 1019 m-3.[1] A system based on a 28 GHz-100ms diode gyrotronmore » will be used to deliver 300 kW through a corrugated waveguide. The microwave heating beam will be directed and focused by a steering mirror located inside the vacuum vessel. Prior to the heating experiments, measurement of the thermal EBW emission (EBE) from the plasma is being made to help determine the optimum launch angle for EBW mode conversion, and also to provide an indication of the electron temperature evolution in over-dense plasmas. A dual-polarized quad-ridged broadband horn is used to measure the EBW emission and polarization at 28 GHz. Initial measurements indicate that the emission in under-dense plasmas corresponds to oblique electron cyclotron emission (ECE) and then converts to EBE when the plasma becomes over-dense during neutral beam injection.« less

  15. Conceptual Model for the Geothermal System of the Wagner Basin, Gulf of California

    NASA Astrophysics Data System (ADS)

    Gonzalez-Fernandez, A.; Neumann, F.; Negrete-Aranda, R.; Contreras, J.; Batista-Cruz, R. Y.; Kretzschmar, T.; Avilés-Esquivel, T. A.; Reyes Ortega, V.; Flores-Luna, C. F.; Gomez-Trevino, E.; Martin, A.; Constable, S.

    2017-12-01

    Cerro Prieto in northwestern Mexico is one of the biggest geothermal plants in the world. Cerro Prieto sits in the Gulf of California rift system, which consists of a series of spreading centers and transform faults. The aim of this study is to evaluate the geothermal potential of the nearby offshore Wagner basin. To this end, we acquired and analyzed a set of different methods, such as reflection seismics, heat flow, magnetotelluric and controlled source electromagnetics, hydrogeochemistry and echosounder. Seismic reflection data show that the Wagner basin is a semi-graben, A profile crossing it shows numerous closely spaced faults, particularly in its eastern part. We found very high heat flow values, in excess of 1000 mW/m2, and large variability on the eastern flank of the Wagner basin, whereas there are more consistent and much lower values across the central and western parts. The high and variable heat flow values are suggestive of advective heat transfer We collected cores and interstitial water samples. The hydrogeochemistry analyses show that in the cores recovered from high heat flow areas, the relations bromide/choride and bromide/sulfide are clearly different from sea water. In contrast, those relations were close to sea water in areas with low heat flow. Similarly, the isotope relations such as 2H/18O show a similar pattern, further indicating the groundwater origin of the interstitial water found in high heat flow zones. In the magnetoteluric measurements we found the presence of a deep conductor that is located approximately under the basin center, extends from the base of the crust to depths of about 40 km, and dips toward the NE. This conductor is probably related to the heat source of the geothermal system. Active source electromagnetics show the presence of shallow conductors that correlate with the faults visible in the seismic sections. There are two distinct conductors, one in the eastern flank and another in the western flank of the basin. The echosounder data and previous studies support the presence of fluid discharge, focused specially in the eastern part of the basin. According to our results, there is recharge in the western part of the basin, a deep heat source beneath the basin, related to the rift process, and groundwater discharge in the eastern part of the basin, channeled by closely spaced faults.

  16. Heat acclimation and cross-tolerance against novel stressors: genomic-physiological linkage.

    PubMed

    Horowitz, Michal

    2007-01-01

    Heat acclimation (AC) is a "within lifetime" reversible phenotypic adaptation, enhancing thermotolerance and heat endurance via a transition to "efficient" cellular performance when acclimatory homeostasis is reached. An inseparable outcome of AC is the development of cross-tolerance (C-T) against novel stressors. This chapter focuses on central plasticity and the molecular-physiological linkage of acclimatory and C-T responses. A drop in temperature thresholds (T-Tsh) for activation of heat-dissipation mechanisms and an elevated T-Tsh for thermal injury development imply autonomic nervous system (ANS) and cytoprotective network involvement in these processes. During acclimation, the changes in T-Tsh for heat dissipation are biphasic. Initially T-Tsh drops, signifying the early autonomic response, and is associated with perturbed peripheral effector cellular performance. Pre-acclimation values return when acclimatory homeostasis is achieved. The changes in the ANS suggest that acclimatory plasticity involves molecular and cellular changes. These changes are manifested by the activation of central peripheral molecular networks and post-translational modifications. Sympathetic induction of elevated HSP 72 reservoirs, with faster heat shock response, is only one example of this. The global genomic response, detected using gene-chips and cluster analyses imply upregulation of genes encoding ion channels, pumps, and transporters (markers for neuronal excitability) in the hypothalamus at the onset of AC and down regulation of metabotrophic genes upon long term AC. Peripherally, the transcriptional program indicates a two-tier defense strategy. The immediate transient response is associated with the maintenance of DNA and cellular integrity. The sustained response correlates with long-lasting cytoprotective-signaling networks. C-T is recorded against cerebral hypoxia, hyperoxia, and traumatic brain injury. Using the highly developed ischemic/reperfused heart model as a baseline, it is evident that C-T stems via protective shared pathways developed with AC. These comprise constitutive elevation of HIF 1alpha and associated target pathways, HSPs, anti-apoptosis, and antioxidative pathways. Collectively the master regulators of AC and C-T are still enigmatic; however, cutting-edge investigative techniques, using a broad molecular approach, challenge current ideas, and the data accumulated will pinpoint novel pathways and provide new perspectives.

  17. Heated CO(2) with or without humidification for minimally invasive abdominal surgery.

    PubMed

    Birch, Daniel W; Manouchehri, Namdar; Shi, Xinzhe; Hadi, Ghassan; Karmali, Shahzeer

    2011-01-19

    Intraoperative hypothermia during both open and laparoscopic abdominal surgery may be associated with adverse events. For laparoscopic abdominal surgery, the use of heated insufflation systems for establishing pneumoperitoneum has been described to prevent hypothermia. Humidification of the insufflated gas is also possible. Past studies have shown inconclusive results with regards to maintenance of core temperature and reduction of postoperative pain and recovery times. To determine the effect of heated gas insufflation on patient outcomes following minimally invasive abdominal surgery. The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE (PubMed), EMBASE, International Pharmaceutical Abstracts (IPA), Web of Science, Scopus, www.clinicaltrials.gov and the National Research Register were searched (1956 to 14 June 2010). Grey literature and cross-references were also searched. Searches were limited to human studies without language restriction. All included studies were randomized trials comparing heated (with or without humidification) gas insufflation with cold gas insufflation in adult and pediatric populations undergoing minimally invasive abdominal procedures. Study quality was assessed in regards to relevance, design, sequence generation, allocation concealment, blinding, possibility of incomplete data and selective reporting. The selection of studies for the review was done independently by two authors, with any disagreement resolved in consensus with a third co-author. Screening of eligible studies, data extraction and methodological quality assessment of the trials were performed by the authors. Data from eligible studies were collected using data sheets. Results were presented using mean differences for continuous outcomes and relative risks with 95% confidence intervals for dichotomous outcomes. The estimated effects were calculated using the latest version of RevMan software. Publication bias was taken into consideration and funnel plots were compiled. Sixteen studies were included in the analysis. During laparoscopic abdominal surgery, no effect on postoperative pain nor changes in core temperature, morphine consumption, length of hospitalisation, lens fogging, length of operation or recovery room stay were associated with heated compared to cold gas insufflation with or without humidification. The study offers evidence that during laparoscopic abdominal surgery, heated gas insufflation, with or without humidification, has minimal benefit on patient outcomes.

  18. Water and Energy Balance in Response to the Removal of Invasive Phragmites Australis in a Riparian Wetland

    NASA Astrophysics Data System (ADS)

    Mykleby, P.; Lenters, J. D.; Cutrell, G. J.; Herrman, K.; Istanbulluoglu, E.; Scott, D.

    2011-12-01

    Vegetation plays an important role in the surface energy and water balance of wetlands. Transpiration from phreatophytes, in particular, withdraws water directly from groundwater, often impacting streamflow rates in adjacent tributaries. In the Republican River basin of the Central Plains (USA), streamflow has declined significantly in the past 30-40 years. Invasive vegetation species (such as Phragmites australis) have been removed from portions of the riparian corridor in an effort to halt or reverse the downward trend in streamflow. In this study, we investigated the energy and water balance of a P. australis-dominated riparian wetland in south-central Nebraska to assess the potential effectiveness of such an approach. Evapotranspiration (ET) rates were measured during two growing seasons - one being 2009, when the P. australis was at full growth, and the other during 2010, after the vegetation had been sprayed with herbicide (and remained only as dead, standing biomass). Energy balance measurements at the field site included net radiation, heat storage rates in the canopy, soil, and standing water, and sensible heat flux, which was measured using a large-aperture scintillometer (LAS). Latent heat flux (i.e., ET) was calculated as a residual of the energy balance, and comparisons were made between the two growing seasons. As a result of the spraying of the P. australis vegetation, season-mean ET rates dropped from 4.4 mm day-1 in 2009 to 3.0 mm day-1 in 2010. This decrease in ET was associated with a large increase in sensible heat flux, which more than doubled between the two years (from 33 W m-2 in 2009 to 76 W m-2 in 2010). Meteorological conditions at the site were slightly different from one year to the next, but the differences were not large enough to account for the dramatic changes in latent and sensible heat flux that were observed. We conclude, therefore, that the majority of the ~30% decrease in ET (and ~130% increase in sensible heat flux) was the result of the invasive removal. This suggests that eradication of P. australis from riparian systems - at least in the initial year following removal - has the potential to provide some "water savings" in the form of groundwater recharge and/or surface runoff to local stream systems. Whether or not such water savings can be sustained in the long term would ultimately depend on the type of vegetation that establishes itself to replace the P. australis land cover.

  19. 11. VIEW OF THE MANIPULATOR AND THE PARTS HEATING FURNACE. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. VIEW OF THE MANIPULATOR AND THE PARTS HEATING FURNACE. THE PARTS OR METALS WERE HEATED PRIOR TO BEING PRESSED. THE MANIPULATOR ARM WAS USED TO INSERT AND REMOVE PARTS OR METALS FROM THE FURNACE. (2/9/79) - Rocky Flats Plant, Uranium Rolling & Forming Operations, Southeast section of plant, southeast quadrant of intersection of Central Avenue & Eighth Street, Golden, Jefferson County, CO

  20. Gamma-ray spectrometry in the field: Radioactive heat production in the Central Slovakian Volcanic Zone

    NASA Astrophysics Data System (ADS)

    Harley, Thomas L.; Westaway, Rob; McCay, Alistair T.

    2017-05-01

    We report 62 sets of measurements from central-southern Slovakia, obtained using a modern portable gamma-ray spectrometer, which reveal the radioactive heat production in intrusive and extrusive igneous rocks of the Late Cenozoic Central Slovakian Volcanic Zone. Sites in granodiorite of the Štiavnica pluton are thus shown to have heat production in the range 2.2-4.9 μW m- 3, this variability being primarily a reflection of variations in content of the trace element uranium. Sites in dioritic parts of this pluton have a lower, but overlapping, range of values, 2.1-4.4 μW m- 3. Sites that have been interpreted in adjoining minor dioritic intrusions of similar age have heat production in the range 1.4-3.3 μW m- 3. The main Štiavnica pluton has zoned composition, with potassium and uranium content and radioactive heat production typically increasing inward from its margins, reflecting variations observed in other granodioritic plutons elsewhere. It is indeed possible that the adjoining dioritic rocks, hitherto assigned to other minor intrusions of similar age, located around the periphery of the Štiavnica pluton, in reality provide further evidence for zonation of the same pluton. The vicinity of this pluton is associated with surface heat flow 40 mW m- 2 above the regional background. On the basis of our heat production measurements, we thus infer that the pluton has a substantial vertical extent, our preferred estimate for the scale depth for its downward decrease in radioactive heat production being 8 km. Nonetheless, this pluton lacks any significant negative Bouguer gravity anomaly. We attribute this to the effect of the surrounding volcanic caldera, filled with relatively low-density lavas, 'masking' the pluton's own gravity anomaly. We envisage that emplacement occurred when the pluton was much hotter, and thus of lower density, than at present, its continued uplift, evident from the local geomorphology, being the isostatic consequence of localized erosion. The heat production in this intrusion evidently plays a significant role, hitherto unrecognized, in the regional geothermics.

  1. Central Control of Brown Adipose Tissue Thermogenesis

    PubMed Central

    Morrison, Shaun F.; Madden, Christopher J.; Tupone, Domenico

    2011-01-01

    Thermogenesis, the production of heat energy, is an essential component of the homeostatic repertoire to maintain body temperature during the challenge of low environmental temperature and plays a key role in elevating body temperature during the febrile response to infection. Mitochondrial oxidation in brown adipose tissue (BAT) is a significant source of neurally regulated metabolic heat production in many species from mouse to man. BAT thermogenesis is regulated by neural networks in the central nervous system which responds to feedforward afferent signals from cutaneous and core body thermoreceptors and to feedback signals from brain thermosensitive neurons to activate BAT sympathetic nerve activity. This review summarizes the research leading to a model of the feedforward reflex pathway through which environmental cold stimulates BAT thermogenesis and includes the influence on this thermoregulatory network of the pyrogenic mediator, prostaglandin E2, to increase body temperature during fever. The cold thermal afferent circuit from cutaneous thermal receptors, through second-order thermosensory neurons in the dorsal horn of the spinal cord ascends to activate neurons in the lateral parabrachial nucleus which drive GABAergic interneurons in the preoptic area (POA) to inhibit warm-sensitive, inhibitory output neurons of the POA. The resulting disinhibition of BAT thermogenesis-promoting neurons in the dorsomedial hypothalamus activates BAT sympathetic premotor neurons in the rostral ventromedial medulla, including the rostral raphe pallidus, which provide excitatory, and possibly disinhibitory, inputs to spinal sympathetic circuits to drive BAT thermogenesis. Other recently recognized central sites influencing BAT thermogenesis and energy expenditure are also described. PMID:22389645

  2. Effect of Ducted HPWH on Space-Conditioning and Water Heating Energy Use -- Central Florida Lab Home

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

    Colon, Carlos; Martin, Eric; Parker, Danny

    2016-11-01

    The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWHs) on space conditioning and water heating energy use in residential applications. Two identical HPWHs, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

  3. Effect of Ducted HPWH on Space-Conditioning and Water Heating Energy Use -- Central Florida Lab Home

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

    Colon, Carlos; Martin, Eric; Parker, Danny

    2016-11-01

    The purpose of this research is to investigate the impact of ducted heat pump water heaters (HPWH's) on space conditioning and water heating energy use in residential applications. Two identical HPWH's, each of 60 gallon capacity were tested side by side at the Flexible Residential Test facility (FRTF) laboratories of the Florida Solar Energy Center (FSEC) campus in Cocoa, Florida. The water heating experiments were run in each test house from July 2014 until February 2015.

  4. Application of X-Ray Computer Tomography for Observing the Central Void Formations and the Fuel Pin Deformations of Irradiated FBR Fuel Assemblies

    NASA Astrophysics Data System (ADS)

    Katsuyama, Kozo; Nagamine, Tsuyoshi; Furuya, Hirotaka

    2010-10-01

    In order to observe the structural change in the interior of irradiated fuel assemblies, a non-destructive post-irradiation examination (PIE) technique using X-ray computer tomography (X-ray CT) was developed. This X-ray CT technique was applied to observe the central void formations and fuel pin deformations of fuel assemblies which had been irradiated at high linear heat rating. The central void sizes in all fuel pins were measured on five cross sections of the core fuel column as a parameter for evaluating fuel thermal performance. In addition, the fuel pin deformations were analyzed from X-ray CT images obtained along the axial direction of a fuel assembly at the same separation interval. A dependence of void size on the linear heat rating was seen in the fuel assembly irradiated at high linear heat rating. In addition, significant undulations of the fuel pin were observed along the axial direction, coinciding with the wrapping wire pitch in the core fuel column. Application of the developed technique should provide enhanced resolution of measurements and simplify fuel PIEs.

  5. Experimental investigation of an ammonia-based combined power and cooling cycle

    NASA Astrophysics Data System (ADS)

    Tamm, Gunnar Olavi

    A novel ammonia-water thermodynamic cycle, capable of producing both power and refrigeration, was proposed by D. Yogi Goswami. The binary mixture exhibits variable boiling temperatures during the boiling process, which leads to a good thermal match between the heating fluid and working fluid for efficient heat source utilization. The cycle can be driven by low temperature sources such as solar, geothermal, and waste heat from a conventional power cycle, reducing the reliance on high temperature sources such as fossil fuels. A theoretical simulation of the cycle at heat source temperatures obtainable from low and mid temperature solar collectors showed that the ideal cycle could produce power and refrigeration at a maximum exergy efficiency, defined as the ratio of the net work and refrigeration output to the change in availability of the heat source, of over 60%. The exergy efficiency is a useful measure of the cycle's performance as it compares the effectiveness of different cycles in harnessing the same source. An experimental system was constructed to demonstrate the feasibility of the cycle and to compare the experimental results with the theoretical simulations. In this first phase of experimentation, the turbine expansion was simulated with a throttling valve and a heat exchanger. Results showed that the vapor generation and absorption condensation processes work experimentally. The potential for combined turbine work and refrigeration output was evidenced in operating the system. Analysis of losses led to modifications in the system design, which were implemented to yield improvements in heat exchange, vapor generation, pump performance and overall stability. The research that has been conducted verifies the potential of the power and cooling cycle as an alternative to using conventional fossil fuel technologies. The research that continues is to further demonstrate the concept and direct it towards industry. On the large scale, the cycle can be used for industrial power production or as a central power plant for a community, with refrigeration produced as required by the application. On the small scale, an affordable residential or commercial unit could allow independent electricity generation for the home or business while also cooling it.

  6. Fluid restriction during exercise in the heat reduces tolerance to progressive central hypovolaemia.

    PubMed

    Schlader, Zachary J; Gagnon, Daniel; Rivas, Eric; Convertino, Victor A; Crandall, Craig G

    2015-08-01

    What is the central question of this study? Interactions between dehydration, as occurs during exercise in the heat without fluid replacement, and hyperthermia on the ability to tolerate central hypovolaemia are unknown. What is the main finding and its importance? We show that inadequate fluid intake during exercise in the heat can impair tolerance to central hypovolaemia even when it elicits only mild dehydration. These findings suggest that hydration during physical work in the heat has important military and occupational relevance for protection against the adverse effects of a subsequent haemorrhagic injury. This study tested the hypothesis that dehydration induced via exercise in the heat impairs tolerance to central hypovolaemia. Eleven male subjects (32 ± 7 years old, 81.5 ± 11.1 kg) walked (O2 uptake 1.7 ± 0.4 l min(-1) ) in a 40°C, 30% relative humidity environment on three occasions, as follows: (i) subjects walked for 90 min, drinking water to offset sweat loss (Hydrated, n = 11); (ii) water intake was restricted, and exercise was terminated when intestinal temperature increased to the same level as in the Hydrated trial (Isothermic Dehydrated, n = 11); and (iii) water intake was restricted, and exercise duration was 90 min (Time Match Dehydrated, n = 9). For each trial, tolerance to central hypovolaemia was determined following exercise via progressive lower body negative pressure and quantified as time to presyncope. Increases in intestinal temperature prior to lower body negative pressure were not different (P = 0.91) between Hydrated (1.1 ± 0.4°C) and Isothermic Dehydrated trials (1.1 ± 0.4°C), but both were lower than in the Time Match Dehydrated trial (1.7 ± 0.5°C, P < 0.01). Prior to lower body negative pressure, body weight was unchanged in the Hydrated trial (-0.1 ± 0.2%), but was reduced in Isothermic Dehydrated (-0.9 ± 0.4%) and further so in Time Match Dehydrated trial (-1.9 ± 0.6%, all P < 0.01). Time to presyncope was greater in Hydrated (14.7 ± 3.2 min) compared with Isothermic Dehydrated (11.9 ± 3.3 min, P < 0.01) and Time Match Dehydrated trials (10.2 ± 1.6 min, P = 0.03), which were not different (P = 0.19). These data indicate that inadequate fluid intake during exercise in the heat reduces tolerance to central hypovolaemia independent of increases in body temperature. © 2015 The Authors. Experimental Physiology © 2015 The Physiological Society.

  7. Analysis of pre-heated fuel combustion and heat-emission dynamics in a diesel engine

    NASA Astrophysics Data System (ADS)

    Plotnikov, S. A.; Kartashevich, A. N.; Buzikov, S. V.

    2018-01-01

    The article explores the feasibility of diesel fuel pre-heating. The research goal was to obtain and analyze the performance diagrams of a diesel engine fed with pre-heated fuel. The engine was tested in two modes: at rated RPMs and at maximum torque. To process the diagrams the authors used technique developed by the Central Diesel Research Institute (CDRI). The diesel engine’s heat emission curves were obtained. The authors concluded that fuel pre-heating shortened the initial phase of the combustion process and moderated the loads, thus making it possible to boost a diesel engine’s mean effective pressure.

  8. Seasonal thermal storage: Swedish practice, developments and cost projections

    NASA Astrophysics Data System (ADS)

    Margen, P.

    1981-06-01

    The types of heat store being developed in Sweden for seasonal storage of heat are discussed. This type of storage allows summer excess heat from industrial waste heat plants, garbage burning plants and future central solar heat stations to be stored for winter use on district heating networks. Whereas above ground steel or concrete tanks are usually too expensive insulated earth pits, uninsulated rock caverns and deep ground schemes using rock or clay promise to achieve sufficiently low costs to justify storage when supplied with free or cheap summer treat. For all these concepts demonstration plants were or are being built in Sweden.

  9. Advanced Thermal Storage for Central Receivers with Supercritical Coolants

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

    Kelly, Bruce D.

    2010-06-15

    The principal objective of the study is to determine if supercritical heat transport fluids in a central receiver power plant, in combination with ceramic thermocline storage systems, offer a reduction in levelized energy cost over a baseline nitrate salt concept. The baseline concept uses a nitrate salt receiver, two-tank (hot and cold) nitrate salt thermal storage, and a subcritical Rankine cycle. A total of 6 plant designs were analyzed, as follows: Plant Designation Receiver Fluid Thermal Storage Rankine Cycle Subcritical nitrate salt Nitrate salt Two tank nitrate salt Subcritical Supercritical nitrate salt Nitrate salt Two tank nitrate salt Supercritical Lowmore » temperature H2O Supercritical H2O Two tank nitrate salt Supercritical High temperature H2O Supercritical H2O Packed bed thermocline Supercritical Low temperature CO2 Supercritical CO2 Two tank nitrate salt Supercritical High temperature CO2 Supercritical CO2 Packed bed thermocline Supercritical Several conclusions have been drawn from the results of the study, as follows: 1) The use of supercritical H2O as the heat transport fluid in a packed bed thermocline is likely not a practical approach. The specific heat of the fluid is a strong function of the temperatures at values near 400 °C, and the temperature profile in the bed during a charging cycle is markedly different than the profile during a discharging cycle. 2) The use of supercritical CO2 as the heat transport fluid in a packed bed thermocline is judged to be technically feasible. Nonetheless, the high operating pressures for the supercritical fluid require the use of pressure vessels to contain the storage inventory. The unit cost of the two-tank nitrate salt system is approximately $24/kWht, while the unit cost of the high pressure thermocline system is nominally 10 times as high. 3) For the supercritical fluids, the outer crown temperatures of the receiver tubes are in the range of 700 to 800 °C. At temperatures of 700 °C and above, intermetallic compounds can precipitate between, and within, the grains of nickel alloys. The precipitation leads to an increase in tensile strength, and a decrease in ductility. Whether the proposed tube materials can provide the required low cycle fatigue life for the supercritical H2O and CO2 receivers is an open question. 4) A ranking of the plants, in descending order of technical and economic feasibility, is as follows: i) Supercritical nitrate salt and baseline nitrate salt: equal ratings ii) Low temperature supercritical H2O iii) Low temperature supercritical CO2 iv) High temperature supercritical CO2 v) High temperature supercritical H2O 5) The two-tank nitrate salt thermal storage systems are strongly preferred over the thermocline systems using supercritical heat transport fluids.« less

  10. The GOL-NB program: further steps in multiple-mirror confinement research

    NASA Astrophysics Data System (ADS)

    Postupaev, V. V.; Batkin, V. I.; Beklemishev, A. D.; Burdakov, A. V.; Burmasov, V. S.; Chernoshtanov, I. S.; Gorbovsky, A. I.; Ivanov, I. A.; Kuklin, K. N.; Mekler, K. I.; Rovenskikh, A. F.; Sidorov, E. N.; Yurov, D. V.

    2017-03-01

    Physical and technical details of the GOL-NB project are presented. GOL-NB is a medium-scale multiple-mirror trap that is under development in the Budker Institute, Novosibirsk, Russia. This device will be created in several years as a deep conversion of the existing GOL-3 facility. It will consist of a central trap with two 0.75 MW neutral beams, two multiple-mirror solenoids, two expander tanks and a plasma gun that creates the start plasma. The central trap with the neutral beam injection-heated plasma is a compact gas-dynamic system. The multiple-mirror sections should decrease the power and particle losses along the magnetic field. The confinement improvement factor depends on plasma parameters and on the magnetic configuration in the multiple mirrors. The main physical task of GOL-NB is direct demonstration of the performance of multiple-mirror sections that will change equilibrium plasma parameters in the central trap. In this paper we discuss results of the scenario modeling and progress in the hardware.

  11. A Modelica-based Model Library for Building Energy and Control Systems

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

    Wetter, Michael

    2009-04-07

    This paper describes an open-source library with component models for building energy and control systems that is based on Modelica, an equation-based objectoriented language that is well positioned to become the standard for modeling of dynamic systems in various industrial sectors. The library is currently developed to support computational science and engineering for innovative building energy and control systems. Early applications will include controls design and analysis, rapid prototyping to support innovation of new building systems and the use of models during operation for controls, fault detection and diagnostics. This paper discusses the motivation for selecting an equation-based object-oriented language.more » It presents the architecture of the library and explains how base models can be used to rapidly implement new models. To demonstrate the capability of analyzing novel energy and control systems, the paper closes with an example where we compare the dynamic performance of a conventional hydronic heating system with thermostatic radiator valves to an innovative heating system. In the new system, instead of a centralized circulation pump, each of the 18 radiators has a pump whose speed is controlled using a room temperature feedback loop, and the temperature of the boiler is controlled based on the speed of the radiator pump. All flows are computed by solving for the pressure distribution in the piping network, and the controls include continuous and discrete time controls.« less

  12. Teleconnections, Midlatitude Cyclones and Aegean Sea Turbulent Heat Flux Variability on Daily Through Decadal Time Scales

    NASA Technical Reports Server (NTRS)

    Romanski, Joy; Romanou, Anastasia; Bauer, Michael; Tselioudis, George

    2013-01-01

    We analyze daily wintertime cyclone variability in the central and eastern Mediterranean during 1958-2001, and identify four distinct cyclone states, corresponding to the presence or absence of cyclones in each basin. Each cyclone state is associated with wind flows that induce characteristic patterns of cooling via turbulent (sensible and latent) heat fluxes in the eastern Mediterranean basin and Aegean Sea. The relative frequency of occurrence of each state determines the heat loss from the Aegean Sea during that winter, with largest heat losses occurring when there is a storm in the eastern but not central Mediterranean (eNOTc), and the smallest occurring when there is a storm in the central but not eastern Mediterranean (cNOTe). Time series of daily cyclone states for each winter allow us to infer Aegean Sea cooling for winters prior to 1985, the earliest year for which we have daily heat flux observations. We show that cyclone states conducive to Aegean Sea convection occurred in 1991/1992 and 1992/1993, the winters during which deep water formation was observed in the Aegean Sea, and also during the mid-1970s and the winters of 1963/1964 and 1968/1969. We find that the eNOTc cyclone state is anticorrelated with the North Atlantic Oscillation (NAO) prior to 1977/1978. After 1977/1978, the cNOTe state is anticorrelated with both the NAO and the North Caspian Pattern (NCP), showing that the area of influence of large scale atmospheric teleconnections on regional cyclone activity shifted from the eastern to the central Mediterranean during the late 1970s. A trend toward more frequent occurrence of the positive phase of the NAO produced less frequent cNOTe states since the late 1970s, increasing the number of days with strong cooling of the Aegean Sea surface waters.

  13. Molecular symmetry determines the mechanism of a very efficient ultrafast excitation-to-heat conversion in Ni-substituted chlorophylls.

    PubMed

    Pilch, Mariusz; Dudkowiak, Alina; Jurzyk, Barbara; Lukasiewicz, Jędrzej; Susz, Anna; Stochel, Grażyna; Fiedor, Leszek

    2013-01-01

    In the Ni-substituted chlorophylls, an ultrafast (<60 fs) deactivation channel is created, which is not present in Ni-porphyrins. This observation prompted us to investigate in detail the mechanism of excitation-to-heat conversion in Ni-substituted chlorophylls, experimentally, using time-resolved laser-induced optoacoustic spectroscopy, and theoretically, using group theory approach. The Ni-substituted chlorophylls show exceptional photostability and the optoacoustic measurements confirm the prompt and very efficient (100%) excitation-into-heat conversion in these complexes. Considering their excellent spectral properties and the loss-free excitation-into-heat conversion they are likely to become a new class of versatile photocalorimetric references. The curious features of the Ni-substituted chlorophylls originate from the symmetry of a ligand field created in the central cavity. The central N-Ni(2+) bonds, formed via the donation of two electrons from each of the sp(2) orbitals of two central nitrogens to an empty [Formula: see text] hybrid centered on Ni(2+), have a considerable covalent character. The extreme rate of excited state relaxation is then not due to a ladder of the metal centered d-states, often invoked in metalloporphyrins, but seems to result from a peculiar topology of the potential energy surface (a saddle-shaped crossing) due to the covalent character of the N-Ni(2+) bonds. This is confirmed by a strong 0→0 character of electronic transitions in these complexes indicating a similarity of their equilibrium geometries in the ground (S(0)) and the excited states (both Q(X) and Q(Y)). The excitation energy is very efficiently converted into molecular vibrations and dissipated as heat, involving the central Ni(2+). These Ni-substituted pigments pose a fine exemplification of symmetry control over properties of excited states of transition metal complexes. Copyright © 2012. Published by Elsevier B.V.

  14. [Mathematical modeling for conditionality of cardiovascular disease by housing conditions].

    PubMed

    Meshkov, N A

    2014-01-01

    There was studied the influence of living conditions (housing area per capita, availability of housing water supply, sewerage and central heating) on the morbidity of the cardiovascular diseases in child and adult population. With the method of regression analysis the morbidity rate was established to significantly decrease with the increase in the area of housing, constructed models are statistically significant, respectively, p = 0.01 and p = 0.02. There was revealed the relationship of the morbidity rate of cardiovascular diseases in children and adults with the supply with housing central heating (p = 0.02 and p = 0.009).

  15. Understanding the Role of the Saharan Heat Low in Modifying Atmospheric Dust Distributions - Observations From Two Research Aircraft Flying Simultaneously Over Western Africa

    NASA Astrophysics Data System (ADS)

    Engelstaedter, S.; Washington, R.; Allen, C.; Flamant, C.; Chaboureau, J.-P.; Kocha, C.; Lavaysse, C.

    2012-04-01

    The near-surface low pressure system that develops over western Africa in Boreal summer (know as the Saharan Heat Low) is thought to have a significant influence on regional and global climate due to its links with the Monsoon, the Northern Atlantic and the Mediterranean climate system. The SHL is associated with the deepest atmospheric boundary layer on the planet and is co-located with the highest dust loadings in the world. The processes that link the heat low and dust distribution are only poorly understood. Improving the representation of the heat low and the processes that control the emission and atmospheric distribution of dust in climate and NWP models is crucial if we are to reduce known systematic errors in climate predictions and weather forecasts. In collaboration with European partners, the UK-based consortium project "Fennec - The Saharan Climate System" aims at improving our understanding of this complex climate system by integrating for the first time coordinated ground and aircraft observations from the central Sahara, newly developed satellite products, and the application of regional and global models. On 22 June 2011, two research aircraft operating out of Fuerteventura (Spain) surveyed the Saharan Heat Low centred over Mauritania-Mali border. The aircraft flew simultaneously in the morning and in the afternoon on two different tracks thereby sampling each track four times on that day. Both aircraft were equipped with a downward looking LIDAR for aerosol detection. In total, 51 sondes were dropped during the flights making this the most comprehensive dataset to study the spatio-temporal diurnal evolution of the heat low including the interactions between the atmospheric boundary layer and dust distributions. Combining LIDAR observations, satellite imagery and back-trajectory modelling we show that an aged dust layer was present in the heat low region resulting from previous day's dust activity associated with a south-moving density current from the Atlas mountains and westward-moving Haboob fronts originating along the Algeria-Mali border. We show how the dust is distributed within the atmosphere and how it is modified during the course of the day by various processes including the development of the atmospheric boundary layer and associated dry convection as well as the inflow of moisture-rich monsoon air from the south.

  16. The warming trend of ground surface temperature in the Choshui Alluvial Fan, western central Taiwan

    NASA Astrophysics Data System (ADS)

    Chen, W.; Chang, M.; Chen, J.; Lu, W.; Huang, C. C.; Wang, Y.

    2013-12-01

    Heat storage in subsurface of the continents forms a fundamental component of the global energy budget and plays an important role in the climate system. Several researches revealed that subsurface temperatures were being increased to 1.8-2.8°C higher in mean ground surface temperature (GST) for some Asian cities where are experiencing a rapid growth of population. Taiwan is a subtropic-tropic island with densely populated in the coastal plains surrounding its mountains. We investigate the subsurface temperature distribution and the borehole temperature-depth profiles by using groundwater monitoring wells in years 2000 and 2010. Our data show that the western central Taiwan plain also has been experiencing a warming trend but with a higher temperatures approximately 3-4 °C of GST during the last 250 yrs. We suggest that the warming were mostly due to the land change to urbanization and agriculture. The current GSTs from our wells are approximately 25.51-26.79 °C which are higher than the current surface air temperature (SAT) of 23.65 °C. Data from Taiwan's weather stations also show 1-1.5 °C higher for the GST than the SAT at neighboring stations. The earth surface heat balance data indicate that GST higher than SAT is reasonable. More researches are needed to evaluate the interaction of GST and SAT, and how a warming GST's impact to the SAT and the climate system of the Earth.

  17. Numerical simulations of hydrothermal circulation resulting from basalt intrusions in a buried spreading center

    USGS Publications Warehouse

    Fisher, A.T.; Narasimhan, T.N.

    1991-01-01

    A two-dimensional, one by two-kilometer section through the seafloor was simulated with a numerical model to investigate coupled fluid and heat flow resulting from basalt intrusions in a buried spreading center. Boundary and initial conditions and physical properties of both sediments and basalt were constrained by field surveys and drilling in the Guaymas Basin, central Gulf of California. Parametric variations in these studies included sediment and basalt permeability, anisotropy in sediment permeability, and the size of heat sources. Faults were introduced through new intrusions both before and after cooling.Background heat input caused fluid convection at velocities ≤ 3 cm a−1 through shallow sediments. Eighty to ninety percent of the heat introduced at the base of the simulations exited through the upper, horizontal surface, even when the vertical boundaries were made permeable to fluid flow. The simulated injection of a 25–50 m thick basalt intrusion at a depth of 250 m resulted in about 10 yr of pore-fluid expulsion through the sea-floor in all cases, leaving the sediments above the intrusions strongly underpressured. A longer period of fluid recharge followed, sometimes accompanied by reductions in total seafloor heat output of 10% in comparison to pre-intrusion values. Additional discharge-recharge events were dispersed chaotically through the duration of the cooling period. These cycles in heat and fluid flow resulted from the response of the simulated system to a thermodynamic shock, the sudden emplacement of a large heat source, and not from mechanical displacement of sediments and pore fluids, which was not simulated.Water/rock mass ratios calculated from numerical simulations are in good agreement with geochemical estimates from materials recovered from the Guaymas Basin, assuming a bulk basalt permeability value of at least 10−17 m2/(10−2 mD). The addition of faults through intrusions and sediments in these simulations did not facilitate continuous, rapid venting. Increased heat input at the base of the faults resulted in temporarily greater fluid discharge, but the flow could not be sustained because the modeled system could not recharge cold fluid quickly enough to remove sufficient heat through the vents.

  18. Long-term Turbulent Sensible-Heat-Flux Measurements with a Large-Aperture Scintillometer in the Centre of Łódź, Central Poland

    NASA Astrophysics Data System (ADS)

    Zieliński, Mariusz; Fortuniak, Krzysztof; Pawlak, Włodzimierz; Siedlecki, Mariusz

    2018-01-01

    We investigate the area-averaged sensible heat flux (QH ) obtained with a scintillometer along a 3.1-km path length over the city centre of Łódź, Central Poland. The annual cycle of QH peaks in June but is lower by the middle of summer. In winter, due to a large amount of anthropogenic heat input, QH remains positive all day long, with positive night-time fluxes also found during months with frequent cold advection, e.g., June 2010. In the diurnal cycle of this flux, several features specific to urban areas are seen: the peak shifts 1-2 h after noon, the heat flux turns from positive to negative 1-2 h after sunset. In Łódź QH was observed during inflow from the north and north-west, i.e. from the city centre. As this area is mostly covered with impervious materials, most of the heat exchanged between the ground and the overlying air is in the form of sensible heat flux. Under the conditions of inflow from the east and south-east, the maximum heat flux is approximately 100 W m^{-2} lower than during the inflow from the city centre, since more vegetation exists to the east and south-east of the scintillometer path. Cold and warm advection are found to be a vital factor in the observed heat-flux variability in the centre of Łódź.

  19. Long-term Turbulent Sensible-Heat-Flux Measurements with a Large-Aperture Scintillometer in the Centre of Łódź, Central Poland

    NASA Astrophysics Data System (ADS)

    Zieliński, Mariusz; Fortuniak, Krzysztof; Pawlak, Włodzimierz; Siedlecki, Mariusz

    2018-06-01

    We investigate the area-averaged sensible heat flux (QH) obtained with a scintillometer along a 3.1-km path length over the city centre of Łódź, Central Poland. The annual cycle of QH peaks in June but is lower by the middle of summer. In winter, due to a large amount of anthropogenic heat input, QH remains positive all day long, with positive night-time fluxes also found during months with frequent cold advection, e.g., June 2010. In the diurnal cycle of this flux, several features specific to urban areas are seen: the peak shifts 1-2 h after noon, the heat flux turns from positive to negative 1-2 h after sunset. In Łódź QH was observed during inflow from the north and north-west, i.e. from the city centre. As this area is mostly covered with impervious materials, most of the heat exchanged between the ground and the overlying air is in the form of sensible heat flux. Under the conditions of inflow from the east and south-east, the maximum heat flux is approximately 100 W m^{-2} lower than during the inflow from the city centre, since more vegetation exists to the east and south-east of the scintillometer path. Cold and warm advection are found to be a vital factor in the observed heat-flux variability in the centre of Łódź.

  20. Glucose Starvation Alters Heat Shock Response, Leading to Death of Wild Type Cells and Survival of MAP Kinase Signaling Mutant

    PubMed Central

    Higgins, LeeAnn; Markowski, Todd; Brambl, Robert

    2016-01-01

    A moderate heat shock induces Neurospora crassa to synthesize large quantities of heat shock proteins that are protective against higher, otherwise lethal temperatures. However, wild type cells do not survive when carbohydrate deprivation is added to heat shock. In contrast, a mutant strain defective in a stress-activated protein kinase does survive the combined stresses. In order to understand the basis for this difference in survival, we have determined the relative levels of detected proteins in the mutant and wild type strain during dual stress, and we have identified gene transcripts in both strains whose quantities change in response to heat shock or dual stress. These data and supportive experimental evidence point to reasons for survival of the mutant strain. By using alternative respiratory mechanisms, these cells experience less of the oxidative stress that proves damaging to wild type cells. Of central importance, mutant cells recycle limited resources during dual stress by undergoing autophagy, a process that we find utilized by both wild type and mutant cells during heat shock. Evidence points to inappropriate activation of TORC1, the central metabolic regulator, in wild type cells during dual stress, based upon behavior of an additional signaling mutant and inhibitor studies. PMID:27870869

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