Science.gov

Sample records for solar desiccant cooling

  1. Desiccant cooling using unglazed transpired solar collectors

    SciTech Connect

    Pesaran, A.A. ); Wipke, K. )

    1992-05-01

    The use of unglazed solar collectors for desiccant regeneration in a solid desiccant cooling cycle was investigated because these collectors are lower in cost than conventional glazed flat-plate collectors. Using computer models, the performance of a desiccant cooling ventilation cycle integrated with either unglazed transpired collectors or conventional glazed flat-plate collectors was obtained. We found that the thermal performance of the unglazed system was lower than the thermal performance of the glazed system because the unglazed system could not take advantage of the heat of adsorption released during the dehumidification process. For a 3-ton cooling system, although the area required for the unglazed collector was 69% more than that required for the glazed collector, the cost of the unglazed collector array was 44% less than the cost of the glazed collector array. The simple payback period of the unglazed system was half of the payback period of the glazed collector when compared to an equivalent gas-fired system. Although the use of unglazed transpired collectors makes economic sense, some practical considerations may limit their use in desiccant regeneration. 8 refs.

  2. Desiccant cooling using unglazed transpired solar collectors

    NASA Astrophysics Data System (ADS)

    Pesaran, A. A.; Wipke, K.

    1992-05-01

    The use of unglazed solar collectors for desiccant regeneration in a solid desiccant cooling cycle was investigated because these collectors are lower in cost than conventional glazed flat-plate collectors. Using computer models, the performance of a desiccant cooling ventilation cycle integrated with either unglazed transpired collectors or conventional glazed flat-plate collectors was obtained. We found that the thermal performance of the unglazed system was lower than the thermal performance of the glazed system because the unglazed system could not take advantage of the heat of adsorption released during the dehumidification process. For a 3-ton cooling system, although the area required for the unglazed collector was 69 percent more than that required for the glazed collector, the cost of the unglazed collector array was 44 percent less than the cost of the glazed collector array. The simple payback period of the unglazed system was half of the payback period of the glazed collector when compared to an equivalent gas-fired system. Although the use of unglazed transpired collectors makes economic sense, some practical considerations may limit their use in desiccant regeneration.

  3. Solar space heating and cooling by selective use of the components of a desiccant cooling system

    NASA Astrophysics Data System (ADS)

    Abbud, Ihsan Aladdin

    The economic advantages of by-passing various components of a desiccant cooling system under conditions not requiring their use are estimated by evaluating the annual costs of heating and cooling a commercial building in three representative U.S. cities. Life-cycle costs of systems employing solar heat for space heating and desiccant regeneration are compared with those using electric heat. The costs of purchasing and operating heating and desiccant cooling systems, with and without solar heat supply, are compared with those employing conventional heating and vapor compression cooling. The conditions under which commercial buildings can be cooled with desiccant systems at costs competitive with conventional systems are identified. A commercially available vapor compression air conditioner is used as a standard of comparison for energy consumption and room comfort. Heating and cooling requirements of the building are determined by use of the BLAST computer model in a simulation of long term system operation. Performance of the desiccant cooling system and life cycle savings obtained by its use are determined by simulation employing the TRNSYS computer model. TRNSYS compatible subroutines are developed to simulate operation of the desiccant equipment, the building, and the controllers that operate and monitor the system components. The results are presented in tabular and graphical form. This study shows that in the widely different climates represented in Los Angeles, New York, and Miami, by-passing various components in the desiccant cooling system when they are not needed is economically advantageous. Operation cost of the complete system decreased by 47.3% in Los Angeles, by 30.9% in New York City, and by 23.9% in Miami by not operating the desiccant wheel and other elements. The ventilation desiccant cooling system has major economic advantage over conventional systems under conditions of moderate humidity, as in Los Angeles and New York City. In Miami, however

  4. Study of parameters affecting the performance of solar desiccant cooling systems

    SciTech Connect

    Pesaran, A A; Hoo, E A

    1993-01-01

    The performance of a solar desiccant cooling system depends on the performance of its components, particularly the desiccant dehumidifier and solar collectors. The desiccant dehumidifier performance is affected by the properties of the desiccant, particularly the shape of the isotherm and the regeneration temperature. The performance of a solar collector, as one would expect, depends on its operating temperature, which is very close to the desiccant regeneration temperature. The purpose of this study was to identify the desiccant isotherm shape (characterized by separation factor) that would result in the optimum performance - based on thermal coefficient of performance and cooling capacity - of a desiccant cooling cycle operating in ventilation mode. Different regeneration temperatures ranging from 65{degree}C to 160{degree}C were investigated to identify the corresponding optimum isotherm shape at each. Thermal COP dictates the required area of the solar collectors, and the cooling capacity is an indication of the size and cost of the cooling equipment. Staged and no-staged regeneration methods were studied.

  5. Study of parameters affecting the performance of solar desiccant cooling systems

    SciTech Connect

    Pesaran, A.A.; Hoo, E.A.

    1993-01-01

    The performance of a solar desiccant cooling system depends on the performance of its components, particularly the desiccant dehumidifier and solar collectors. The desiccant dehumidifier performance is affected by the properties of the desiccant, particularly the shape of the isotherm and the regeneration temperature. The performance of a solar collector, as one would expect, depends on its operating temperature, which is very close to the desiccant regeneration temperature. The purpose of this study was to identify the desiccant isotherm shape (characterized by separation factor) that would result in the optimum performance - based on thermal coefficient of performance and cooling capacity - of a desiccant cooling cycle operating in ventilation mode. Different regeneration temperatures ranging from 65[degree]C to 160[degree]C were investigated to identify the corresponding optimum isotherm shape at each. Thermal COP dictates the required area of the solar collectors, and the cooling capacity is an indication of the size and cost of the cooling equipment. Staged and no-staged regeneration methods were studied.

  6. A low-cost-solar liquid desiccant system for residential cooling

    NASA Astrophysics Data System (ADS)

    Ware, Joel D., III

    The use of liquid desiccants for dehumidification of heating, ventilation, and air conditioning (HVAC) process air is becoming a more promising concept as the drive for energy conservation continues to grow. Recently, liquid desiccant systems have been implemented on the commercial level in conjunction with evaporative coolers and have recorded energy savings upwards of 50%. The aim of this research is to test the potential liquid desiccant systems have on the residential level when paired with a conventional vapor compression cycle and to construct a system that would overcome some of its barriers to the residential market. A complete low-cost-solar liquid desiccant system was designed, constructed, and tested in the Off-Grid Zero Emissions Building (OGZEB) at the Florida State University. Key design characteristics include turbulent process air flow through the conditioner and airside heating in the regenerator. The system was tested in the two following ways: (1) for the energy savings while maintaining a constant temperature over a twenty four hour period and (2) for the energy savings over a single cooling cycle. The liquid desiccant system achieved a maximum energy savings of 38% over a complete day and 52% over a single cooling cycle. It was projected that the system has the potential to save 1064 kWh over the course of a year. When combined with a renewable source of heat for regeneration, liquid desiccant systems become very cost effective. The levelized cost of energy for the combination of the liquid desiccant system and solar thermal collectors was calculated to be 7.06 C/kWh with a payback period of 4.4 years. This research provides evidence of the technology's potential on the residential sector and suggests ways for it to become competitive in the market.

  7. The performance of a solar-regenerated open-cycle desiccant bed grain cooling system

    SciTech Connect

    Ismail, M.Z.; Angus, D.E. ); Thorpe, G.R. )

    1991-01-01

    The cooling of stored food grains suppresses the growth of populations of insect pests, inhibits spoilage by fungi and helps to preserve grain quality. In temperate and subtropical climates, grains may be effectively cooled by ventilating them with ambient air. In tropical climates, the enthalpy of the air must be reduced before it can be used for cooling grain. One method of achieving this is to isothermally reduce the humidity of the air. This paper describes experiments carried out on a simple-to-build solar-regenerated open-cycle grain cooling system. The device consists of a 5.85 m{sup 2} collector coupled with two beds of silica gel. Results from a series of experiments suggest that the device may be used to cool up to 200 tons of grain. The electrical power consumption of the device is of the order of 0.3 watt per ton of grain cooled, and the total electrical energy consumption is of the order of 0.7 kWh per ton of grain stored for a six-month period. The effectiveness of the device is a function of air flow rate and the enthalpy of ambient air, and results presented in this paper suggest that the solar cooling device is particularly effective in tropical climates.

  8. Desiccant degradation in desiccant cooling systems: An experimental study

    SciTech Connect

    Pesaran, A.A.

    1993-11-01

    The authors conducted experiments to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. The source of contamination was cigarette smoke, which is considered one of the worst pollutants in building cooling applications. The authors exposed five different solid desiccants to ``ambient`` and ``contaminated`` humid air: silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. They obtained the moisture capacity of samples as a function of exposure time. Compared to virgin desiccant samples, the capacity loss caused by thermal cycling with humid ambient air was 10 percent to 30 percent for all desiccants. The capacity loss because of combined effect of thermal cycling with ``smoke-filled`` humid air was between 30 percent to 70 percent. The higher losses occurred after four months of experiment time, which is equivalent to four to eight years of field operation. Using a system model and smoke degradation data on silica gel, the authors predicted that, for low-temperature regeneration, the loss in performance of a ventilation-cycle desiccant cooling system would be between 10 percent to 35 percent, in about eight years, with higher value under worst conditions.

  9. Desiccant cooling: State-of-the-art assessment

    SciTech Connect

    Pesaran, A.A.; Penney, T.R.; Czanderna, A.W.

    1992-10-01

    The objectives of this document are to present an overview of the work accomplished to date on desiccant cooling to provide assessment of the state of the art of desiccant cooling technology in the field of desiccant material dehumidifier components, desiccant systems, and models. The report also discusses the factors that affect the widespread acceptance of desiccant cooling technology. This report is organized as follows. First, a basic description and historical overview of desiccant cooling technology is provided. Then, the recent research and development (R D) program history (focusing on DOE's funded efforts) is discussed. The status of the technology elements (materials, components, systems) is discussed in detail and a preliminary study on the energy impact of desiccant technology is presented. R D needs for advancing the technology in the market are identified. The National Renewable Energy Laboratory's unique desiccant test facilities and their typical outputs are described briefly. Finally, the results of a comprehensive literature search on desiccant cooling are presented in a bibliography. The bibliography contains approximately 900 citations on desiccant cooling.

  10. Desiccant cooling: State-of-the-art assessment

    SciTech Connect

    Pesaran, A.A.; Penney, T.R.; Czanderna, A.W.

    1992-10-01

    The objectives of this document are to present an overview of the work accomplished to date on desiccant cooling to provide assessment of the state of the art of desiccant cooling technology in the field of desiccant material dehumidifier components, desiccant systems, and models. The report also discusses the factors that affect the widespread acceptance of desiccant cooling technology. This report is organized as follows. First, a basic description and historical overview of desiccant cooling technology is provided. Then, the recent research and development (R&D) program history (focusing on DOE`s funded efforts) is discussed. The status of the technology elements (materials, components, systems) is discussed in detail and a preliminary study on the energy impact of desiccant technology is presented. R&D needs for advancing the technology in the market are identified. The National Renewable Energy Laboratory`s unique desiccant test facilities and their typical outputs are described briefly. Finally, the results of a comprehensive literature search on desiccant cooling are presented in a bibliography. The bibliography contains approximately 900 citations on desiccant cooling.

  11. Desiccant dehumidification and cooling systems assessment and analysis

    SciTech Connect

    Collier, R.K. Jr.

    1997-09-01

    The objective of this report is to provide a preliminary analysis of the principles, sensitivities, and potential for national energy savings of desiccant cooling and dehumidification systems. The report is divided into four sections. Section I deals with the maximum theoretical performance of ideal desiccant cooling systems. Section II looks at the performance effects of non-ideal behavior of system components. Section III examines the effects of outdoor air properties on desiccant cooling system performance. Section IV analyzes the applicability of desiccant cooling systems to reduce primary energy requirements for providing space conditioning in buildings. A basic desiccation process performs no useful work (cooling). That is, a desiccant material drying air is close to an isenthalpic process. Latent energy is merely converted to sensible energy. Only when heat exchange is applied to the desiccated air is any cooling accomplished. This characteristic is generic to all desiccant cycles and critical to understanding their operation. The analyses of Section I show that desiccant cooling cycles can theoretically achieve extremely high thermal CoP`s (>2). The general conclusion from Section II is that ventilation air processing is the most viable application for the solid desiccant equipment analyzed. The results from the seasonal simulations performed in Section III indicate that, generally, the seasonal performance of the desiccant system does not change significantly from that predicted for outdoor conditions. Results from Section IV show that all of the candidate desiccant systems can save energy relative to standard vapor-compression systems. The largest energy savings are achieved by the enthalpy exchange devise.

  12. An assessment of desiccant cooling and dehumidification technology

    SciTech Connect

    Mei, V.C.; Chen, F.C. ); Lavan, Z. ); Collier, R.K. Jr. ); Meckler, G. )

    1992-07-01

    Desiccant systems are heat-actuated cooling and dehumidification technology. With the recent advances in this technology, desiccant systems can now achieve a primary energy coefficient of performance (COP) between 1.3 and 1.5, with potential to go to 1.7 and higher. It is becoming one of the most promising alternatives to conventional cooling systems. Two important and well-known advantages of desiccant cooling systems are that they are CFC free and they can reduce the electricity peak load. Another important but lesser-known advantage of desiccant technology is its potential for energy conservation. The energy impact study in this report indicated that a possible 13% energy saving in residential cooling and 8% in commercial cooling is possible. Great energy saving potential also exists in the industrial sector if industrial waste heat can be used for desiccant regeneration. The latest study on desiccant-integrated building heating, ventilating, and air conditioning (HVAC) systems indicated that the initial cost for the conventional cooling equipment was greatly reduced by using desiccant technology because of downsized compressors, fans, and ductworks. This cost reduction was more than enough to offset the cost of desiccant equipment. Besides, the system operation cost was also reduced. All these indicate that desiccant systems are also cost effective. This study provides an updated state-of-the-art assessment forsiccant technology in the field of desiccant materials, systems, computer models, and theoretical analyses. From this information the technology options were derived and the future research and development needs were identified. Because desiccant technology has already been applied in the commercial building sector with very encouraging results, it is expected that future market breakthroughs will probably start in this sector. A market analysis for the commercial building application is therefore included.

  13. Annual DOE Active Solar Heating and Cooling Contractors Review meeting

    NASA Astrophysics Data System (ADS)

    1981-09-01

    Ninety three project summaries dicussing the following aspects of active solar heating and cooling are presented: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology.

  14. Development of Membrane-Based Desiccant Fiber for Vacuum Desiccant Cooling.

    PubMed

    Yang, Yifan; Rana, Dipak; Lan, Christopher Q; Matsuura, Takeshi

    2016-06-22

    A novel hydrophobic membrane-based desiccant fiber (MDF) was developed by loading lithium chloride into hydrophobic hollow fiber membranes. The MDF thus made was then tested for vapor absorption under controlled conditions. Furthermore, an MDF pad, which was made by weaving MDF into a piece of garment, was built into a laboratory vacuum desiccant cooling (VDC) setup, which included the MDF pad as the desiccant layer and a cooling towel saturated with water as the water reservoir, to test the cooling effects at atmospheric pressure and vacuum of 25 in. of Hg. Results indicate that MDF is suitable for applications such as in VDC. Mass and heat transfer of vapor absorption by MDF were also analyzed.

  15. Potential Evaluation of Solar Heat Assisted Desiccant Hybrid Air Conditioning System

    NASA Astrophysics Data System (ADS)

    Tran, Thien Nha; Hamamoto, Yoshinori; Akisawa, Atsushi; Kashiwagi, Takao

    The solar thermal driven desiccant dehumidification-absorption cooling hybrid system has superior advantage in hot-humid climate regions. The reasonable air processing of desiccant hybrid air conditioning system and the utility of clean and free energy make the system environment friendly and energy efficient. The study investigates the performance of the desiccant dehumidification air conditioning systems with solar thermal assistant. The investigation is performed for three cases which are combinations of solar thermal and absorption cooling systems with different heat supply temperature levels. Two solar thermal systems are used in the study: the flat plate collector (FPC) and the vacuum tube with compound parabolic concentrator (CPC). The single-effect and high energy efficient double-, triple-effect LiBr-water absorption cooling cycles are considered for cooling systems. COP of desiccant hybrid air conditioning systems are determined. The evaluation of these systems is subsequently performed. The single effect absorption cooling cycle combined with the flat plate collector solar system is found to be the most energy efficient air conditioning system.

  16. Annual DOE active solar heating and cooling contractors' review meeting. Premeeting proceedings and project summaries

    SciTech Connect

    None,

    1981-09-01

    Ninety-three project summaries are presented which discuss the following aspects of active solar heating and cooling: Rankine solar cooling systems; absorption solar cooling systems; desiccant solar cooling systems; solar heat pump systems; solar hot water systems; special projects (such as the National Solar Data Network, hybrid solar thermal/photovoltaic applications, and heat transfer and water migration in soils); administrative/management support; and solar collector, storage, controls, analysis, and materials technology. (LEW)

  17. Cool Earth Solar

    SciTech Connect

    Lamkin, Rob; McIlroy, Andy; Swalwell, Eric; Rajan, Kish

    2013-04-22

    In a public-private partnership that takes full advantage of the Livermore Valley Open Campus (LVOC) for the first time, Sandia National Laboratories and Cool Earth Solar have signed an agreement that could make solar energy more affordable and accessible. In this piece, representatives from Sandia, Cool Earth Solar, and leaders in California government all discuss the unique partnership and its expected impact.

  18. Cool Earth Solar

    ScienceCinema

    Lamkin, Rob; McIlroy, Andy; Swalwell, Eric; Rajan, Kish

    2016-07-12

    In a public-private partnership that takes full advantage of the Livermore Valley Open Campus (LVOC) for the first time, Sandia National Laboratories and Cool Earth Solar have signed an agreement that could make solar energy more affordable and accessible. In this piece, representatives from Sandia, Cool Earth Solar, and leaders in California government all discuss the unique partnership and its expected impact.

  19. Zero Carryover Liquid-Desiccant Air Conditioner for Solar Applications: Preprint

    SciTech Connect

    Lowenstein, A.; Slayzak, S.; Kozubal, E.

    2006-07-01

    A novel liquid-desiccant air conditioner that dries and cools building supply air will transform the use of direct-contact liquid-desiccant systems in HVAC applications, improving comfort, air quality, and providing energy-efficient humidity control.

  20. Performance Assessment of a Desiccant Cooling System in a CHP Application with an IC Engine

    SciTech Connect

    Jalalzadeh-Azar, A. A.; Slayzak, S.; Judkoff, R.; Schaffhauser, T.; DeBlasio, R.

    2005-04-01

    Performance of a desiccant cooling system was evaluated in the context of combined heat and power (CHP). The baseline system incorporated a desiccant dehumidifier, a heat exchanger, an indirect evaporative cooler, and a direct evaporative cooler. The desiccant unit was regenerated through heat recovery from a gas-fired reciprocating internal combustion engine. The system offered sufficient sensible and latent cooling capacities for a wide range of climatic conditions, while allowing influx of outside air in excess of what is typically required for commercial buildings. Energy and water efficiencies of the desiccant cooling system were also evaluated and compared with those of a conventional system. The results of parametric assessments revealed the importance of using a heat exchanger for concurrent desiccant post cooling and regeneration air preheating. These functions resulted in enhancement of both the cooling performance and the thermal efficiency, which are essential for fuel utilization improvement. Two approaches for mixing of the return air and outside air were examined, and their impact on the system cooling performance and thermal efficiency was demonstrated. The scope of the parametric analyses also encompassed the impact of improving the indirect evaporative cooling effectiveness on the overall cooling system performance.

  1. Developing, testing, evaluating and optimizing solar heating and cooling systems

    SciTech Connect

    Not Available

    1992-01-24

    The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems; (2) a project to build and test several generic solar water heaters; (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems; (4) a liquid desiccant cooling system development project; (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research; and (6) a management task. The objectives and progress in each task are described in this report.

  2. Prototype solar heating and cooling systems, including potable hot water

    NASA Technical Reports Server (NTRS)

    Bloomquist, D.; Oonk, R. L.

    1977-01-01

    Progress made in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water is reported. The system consists of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition. A comparison of the proposed Solaron Heat Pump and Solar Desiccant Heating and Cooling Systems, installation drawings, data on the Akron House at Akron, Ohio, and other program activities are included.

  3. Research and development needs for desiccant cooling technology 1992--1997. (Supplement to the NREL report, Desiccant Cooling: State-of-the-Art Assessment)

    SciTech Connect

    Pesaran, A A

    1992-12-01

    This report is a supplement to Desiccant Cooling: State-of-the-Art Assessment (NREL/TP-254-4147, DE93000013). In this supplement document we have described a detailed program assuming sufficient funding to implement the R&D activities needed. Desiccant dehumidification is a mature technology for industrial applications, and in recent years the technology has been used for air conditioning a number of institutional and commercial buildings. Our proposal is based on argumentative discussions at various national meetings with leaders of the technology. The goal is the penetration of the broad air conditioning market. This work is funded by the Buildings technology Office of the US Department of Energy.

  4. Zero Energy Communities with Central Solar Plants using Liquid Desiccants and Local Storage: Preprint

    SciTech Connect

    Burch, J.; Woods, J.; Kozubal, E.; Boranian, A.

    2012-08-01

    The zero energy community considered here consists of tens to tens-of-thousands of residences coupled to a central solar plant that produces all the community's electrical and thermal needs. A distribution network carries fluids to meet the heating and cooling loads. Large central solar systems can significantly reduce cost of energy vs. single family systems, and they enable economical seasonal heat storage. However, the thermal distribution system is costly. Conventional district heating/cooling systems use a water/glycol solution to deliver sensible energy. Piping is sized to meet the peak instantaneous load. A new district system introduced here differs in two key ways: (i) it continuously distributes a hot liquid desiccant (LD) solution to LD-based heating and cooling equipment in each home; and (ii) it uses central and local storage of both LD and heat to reduce flow rates to meet average loads. Results for piping sizes in conventional and LD thermal communities show that the LD zero energy community reduces distribution piping diameters meeting heating loads by {approx}5X and meeting cooling loads by {approx}8X for cooling, depending on climate.

  5. Research and development needs for desiccant cooling technology 1992--1997

    SciTech Connect

    Pesaran, A.A.

    1992-12-01

    This report is a supplement to Desiccant Cooling: State-of-the-Art Assessment (NREL/TP-254-4147, DE93000013). In this supplement document we have described a detailed program assuming sufficient funding to implement the R D activities needed. Desiccant dehumidification is a mature technology for industrial applications, and in recent years the technology has been used for air conditioning a number of institutional and commercial buildings. Our proposal is based on argumentative discussions at various national meetings with leaders of the technology. The goal is the penetration of the broad air conditioning market. This work is funded by the Buildings technology Office of the US Department of Energy.

  6. Radiative cooling for solar cells

    NASA Astrophysics Data System (ADS)

    Zhu, Linxiao; Raman, Aaswath; Wang, Ken X.; Anoma, Marc A.; Fan, Shanhui

    2015-03-01

    Standard solar cells heat up under sunlight, and the resulting increased temperature of the solar cell has adverse consequences on both its efficiency and its reliability. We introduce a general approach to radiatively lower the operating temperature of a solar cell through sky access, while maintaining its sunlight absorption. We present first an ideal scheme for the radiative cooling of solar cells. For an example case of a bare crystalline silicon solar cell, we show that the ideal scheme can passively lower the operating temperature by 18.3 K. We then show a microphotonic design based on realistic material properties, that approaches the performance of the ideal scheme. We also show that the radiative cooling effect is substantial, even in the presence of significant non-radiative heat change, and parasitic solar absorption in the cooling layer, provided that we design the cooling layer to be sufficiently thin.

  7. Cryopreservation of Quercus suber and Quercus ilex embryonic axes: in vitro culture, desiccation and cooling factors.

    PubMed

    Gonzalez-Benito, M Elena; Prieto, Roberto-Moreno; Herradon, Esther; Martin, Carmen

    2002-01-01

    This study examines different factors included in the cryopreservation protocols for Quercus ilex and Q. suber embryonic axes. In vitro incubation temperature played an important role in the appropriate development of Q. ilex axes, as 15 degrees C was superior to 25 degrees C. Q. suber axes proved to be more sensitive to desiccation and cooling. Poor survival (35%) was observed when axes were included into cryovials and then in liquid nitrogen, and none when immersed in sub-cooled liquid nitrogen (-210 degrees C). Q. ilex axes showed poorly organised development in vitro (c. 50% of non-cooled axes showed shoot development). However, c. 80% survival was observed after cryopreservation (either in liquid nitrogen or sub-cooled liquid nitrogen at 0.34 g water / g dry weight), of which c. 15% showed shoot development.

  8. Solar Heating and Cooling

    ERIC Educational Resources Information Center

    Duffie, John A.; Beckman, William A.

    1976-01-01

    Describes recent research that has made solar energy economically competitive with other energy sources. Includes solar energy building architecture, storage systems, and economic production data. (MLH)

  9. Colorado State University program for developing, testing, evaluating and optimizing solar heating and cooling systems

    SciTech Connect

    Not Available

    1993-01-07

    This program includes six tasks, including (1) a project measuring the performance of unique solar system components, (2) a project to develop a methodology for determining annual performance ratings of solar domestic hot water systems, (3) a project that will identify, analyze, design, build, and experimentally evaluate SDHW systems incorporating advanced concepts and components, (4) a liquid desiccant cooling system development project, (5) a project that will perform TRNSYS simulations to determine potential energy savings for desiccant cooling systems, especially in humid climates, and (6) a management task. The objectives and progress in each task are described.

  10. Developing, testing, evaluating and optimizing solar heating and cooling systems

    SciTech Connect

    Not Available

    1991-11-01

    The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well a previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--1992 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space hearing systems, (2) a project to build and test several generic solar water heaters, (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems, (4) a liquid desiccant cooling system development project, (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research, and (6) a management task. The objectives and progress in each task are described in this report. 6 figs., 2 tabs.

  11. Energy and economic performance analysis of an open cycle solar desiccant dehumidification air-conditioning system for application in Hong Kong

    SciTech Connect

    Li, Yutong; Lu, Lin; Yang, Hongxing

    2010-12-15

    In this article, a transient simulation model and the EnergyPlus were used to study the energy performance and economical feasibility for integrating a solar liquid desiccant dehumidification system with a conventional vapor compression air-conditioning system for the weather condition of Hong Kong. The vapor compression system capacity in the solar assisted air-conditioning system can be reduced to 19 kW from original 28 kW of a conventional air-conditioning system as a case study due to the solar desiccant cooling. The economical performance of the solar desiccant dehumidification system is compared with that of the conventional air-conditioning system. The results show that the energy saving potentials due to incorporation of the solar desiccant dehumidification system in a traditional air-conditioning system is significant for the hot wet weather in Hong Kong due to higher COP resulted from higher supply chilled water temperature from chiller plants. The annual operation energy savings for the hybrid system is 6760 kWh and the payback period of the hybrid system is around 7 years. The study shows that the solar assisted air-conditioning is a viable technology for utilizations in subtropical areas. (author)

  12. Experiences in solar cooling systems

    NASA Astrophysics Data System (ADS)

    Ward, D. S.

    The results of performance evaluations for nine solar cooling systems are presented, and reasons fow low or high net energy balances are discussed. Six of the nine systems are noted to have performed unfavorably compared to standard cooling systems due to thermal storage losses, excessive system electrical demands, inappropriate control strategies, poor system-to-load matching, and poor chiller performance. A reduction in heat losses in one residential unit increased the total system efficiency by 2.5%, while eliminating heat losses to the building interior increased the efficiency by 3.3%. The best system incorporated a lithium bromide absorption chiller and a Rankine cycle compression unit for a commercial application. Improvements in the cooling tower and fan configurations to increase the solar cooling system efficiency are indicated. Best performances are expected to occur in climates inducing high annual cooling loads.

  13. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C

    2013-12-24

    A solar-powered adsorption-desorption refrigeration and air conditioning system uses nanostructural materials made of high specific surface area adsorption aerogel as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material. A circulation system circulates refrigerant from the nanostructural material to a cooling unit.

  14. Experiences in solar cooling systems

    NASA Astrophysics Data System (ADS)

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

    Six of the nine solar cooling systems discussed in this paper had negative energy savings. In several cases the solar cooling system used substantially more energy than a conventional system could have been expected to use. Two systems, however, had significant energy savings. These systems (1 residential and 1 commercial) obtained system thermal efficiencies of 12.0 to 12.4 percent. Their system overall efficiences averaged 11.2 and 5.2 percent respectively. The residential-sized system achieved an annual energy savings of about 16.8 GJ/year, or approximately .34 GJ/year.m2 of collector. The commercial system had equivalent values of 137 GJ/year or about .22 GJ/year/sq m of collector. It should be noted that these efficiencies re much lower than those of well-designed and properly controlled cooling systems in commercial sizes. However, with realistic system modifications and subsequent improvements in performance these solar cooling systems can be expected to achieve savings in nonrenewable energy sources of approximately 1.2 GJ/year/sq m of collector. These savings can be compared to those associated with solar space and domestic hot water heating systems of 2.2 and 2.5 GJ/year/sq m of collector, respectively.

  15. Desiccant contamination research: Report on the desiccant contamination test facility

    SciTech Connect

    Pesaran, A.A.; Bingham, C.E.

    1991-07-01

    The activity in the cooling systems research involves research on high performance dehumidifiers and chillers that can operate efficiently with the variable thermal outputs and delivery temperatures associated with solar collectors. It also includes work on advanced passive cooling techniques. This report describes the work conducted to improve the durability of solid desiccant dehumidifiers by investigating the causes of degradation of desiccant materials from airborne contaminants and thermal cycling. The performance of a dehumidifier strongly depends on the physical properties and durability of the desiccant material. To make durable and reliable dehumidifiers, an understanding is needed of how and to what degree the performance of a dehumidifier is affected by desiccant degradation. This report, an account of work under Cooling Systems Research, documents the efforts to design and fabricate a test facility to investigate desiccant contamination based on industry and academia recommendations. It also discusses the experimental techniques needed for obtaining high-quality data and presents plans for next year. Researchers of the Mechanical and Industrial Technology Division performed this work at the Solar Energy Research Institute in FY 1988 for DOE's Office of Solar Heat Technologies. 7 refs., 19 figs., 1 tab.

  16. Moving Advanced Desiccant Materials into Mainstream Non-CFC Cooling Products

    SciTech Connect

    Sand, J R; Grossman, G; Rice, C K; Fairchild, P D; Gross, I L

    1994-01-01

    Desiccant air-conditioning systems can be used as alternatives for conventional air-conditioning equipment in any commercial or residential building. Recent breakthroughs in desiccant materials technology and the creation of new markets by Indoor Air Quality issues make desiccant-based air-conditioning equipment practical for many space-conditioning applications.

  17. Terrestrial cooling and solar variability

    NASA Technical Reports Server (NTRS)

    Agee, E. M.

    1982-01-01

    Observational evidence from surface temperature records is presented and discussed which suggests a significant cooling trend over the Northern Hemisphere from 1940 to the present. This cooling trend is associated with an increase of the latitudinal gradient of temperature and the lapse rate, as predicted by climate models with decreased solar input and feedback mechanisms. Evidence suggests that four of these 80- to 100-year cycles of global surface temperature fluctuation may have occurred, and in succession, from 1600 to the present. Interpretation of sunspot activity were used to infer a direct thermal response of terrestrial temperature to solar variability on the time scale of the Gleissberg cycle (90 years, an amplitude of the 11-year cycles). A physical link between the sunspot activity and the solar parameter is hypothesized. Observations of sensible heat flux by stationary planetary waves and transient eddies, as well as general circulation modeling results of these processes, were examined from the viewpoint of the hypothesis of cooling due to reduced insolation.

  18. Developing, testing, evaluating and optimizing solar heating and cooling systems. Project status report, November--December 1991

    SciTech Connect

    Not Available

    1992-01-24

    The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems; (2) a project to build and test several generic solar water heaters; (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems; (4) a liquid desiccant cooling system development project; (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research; and (6) a management task. The objectives and progress in each task are described in this report.

  19. Solar-powered cooling system

    DOEpatents

    Farmer, Joseph C.

    2015-07-28

    A solar-powered adsorption-desorption refrigeration and air conditioning system that uses nanostructural materials such as aerogels, zeolites, and sol gels as the adsorptive media. Refrigerant molecules are adsorbed on the high surface area of the nanostructural material while the material is at a relatively low temperature, perhaps at night. During daylight hours, when the nanostructural materials is heated by the sun, the refrigerant are thermally desorbed from the surface of the aerogel, thereby creating a pressurized gas phase in the vessel that contains the aerogel. This solar-driven pressurization forces the heated gaseous refrigerant through a condenser, followed by an expansion valve. In the condenser, heat is removed from the refrigerant, first by circulating air or water. Eventually, the cooled gaseous refrigerant expands isenthalpically through a throttle valve into an evaporator, in a fashion similar to that in more conventional vapor recompression systems.

  20. Advances in Solar Heating and Cooling Systems

    ERIC Educational Resources Information Center

    Ward, Dan S.

    1976-01-01

    Reports on technological advancements in the fields of solar collectors, thermal storage systems, and solar heating and cooling systems. Diagrams aid in the understanding of the thermodynamics of the systems. (CP)

  1. Anisotropic stress accumulation in cooling lava flows and resulting fracture patterns: Insights from starch-water desiccation experiments

    NASA Astrophysics Data System (ADS)

    Lodge, Robert W. D.; Lescinsky, David T.

    2009-09-01

    Desiccation of starch-water slurries is a useful analog for the production of polygonal fractures/columnar joints in cooling lava flows. When left to dry completely, a simple mixture of 1:1 starch and water will produce columns that appear remarkably similar to natural columnar joints formed in cooled lava flows. Columns form when the accumulation of isotropic stress exceeds the tensile strength of a material, at which point a fracture forms and advances through the material perpendicular to the desiccating surface. Individual fractures will initially form orthogonal to the desiccation surface but will quickly evolve into a hexagonal fracture network that advances incrementally through the material. However, some fracture patterns found within natural lava flows are not hexagonal ( Lodge and Lescinsky, 2009-this issue), but rather have fracture lengths that are much longer than the distance to adjacent fractures. These fractures are commonly found at lava flows that have interacted with glacial ice during emplacement. The purpose of this study is to utilize starch analog experiments to better understand the formation of these fractures and the stress regimes responsible for their non-hexagonal patterns. To simulate anisotropic conditions during cooling, the starch slurry was poured into a container with a movable wall that was attached to a screw-type jack. The jack was then set to slowly extend or retract while the slurry desiccated. This resulted in either a decrease or increase in the chamber cross-sectional area thus creating compressional or extensional regimes. Decreasing chamber area (DCA) experiments resulted in fractures with larger lengths parallel to the direction of wall movement (also direction of compression). It also caused localized thrust faulting and curved column development. Increasing chamber area (ICA) experiments produced a zone of horizontal column development along the expanding margin (produced when the wall detached from the sample

  2. The economics of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1978-01-01

    Analytic procedure evaluates cost of combining absorption-cycle chiller with solar-energy system in residential or commercial application. Procedure assumes that solar-energy system already exists to heat building and that cooling system must be added. Decision is whether to cool building with conventional vapor-compression-cycle chiller or to use solar-energy system to provide heat input to absorption chiller.

  3. Solar-Powered, Liquid-Desiccant Air Conditioner for Low-Electricity Humidity Control: Report and Summary Report

    SciTech Connect

    Dean, J.; Kozubal, E.; Herrmann, L.; Miller, J.; Lowenstein, A.; Barker, G.; Slayzak, S.

    2012-11-01

    The primary objective of this project was to demonstrate the capabilities of a new high-performance, liquid-desiccant dedicated outdoor air system (DOAS) to enhance cooling efficiency and comfort in humid climates while substantially reducing electric peak demand at Tyndall Air Force Base (AFB), which is 12 miles east of Panama City, Florida.

  4. Solar residential heating and cooling system

    NASA Technical Reports Server (NTRS)

    Melton, D. E.; Humphries, W. R.

    1975-01-01

    System has been placed in operation to verify technical feasibility of using solar energy to provide residential heating and cooling. Complete system analysis was performed to provide design information.

  5. Seminar 14 - Desiccant Enhanced Air Conditioning: Desiccant Enhanced Evaporative Air Conditioning (Presentation)

    SciTech Connect

    Kozubal, E.

    2013-02-01

    This presentation explains how liquid desiccant based coupled with an indirect evaporative cooler can efficiently produce cool, dry air, and how a liquid desiccant membrane air conditioner can efficiently provide cooling and dehumidification without the carryover problems of previous generations of liquid desiccant systems. It provides an overview to a liquid desiccant DX air conditioner that can efficiently provide cooling and dehumidification to high latent loads without the need for reheat, explains how liquid desiccant cooling and dehumidification systems can outperform vapor compression based air conditioning systems in hot and humid climates, explains how liquid desiccant cooling and dehumidification systems work, and describes a refrigerant free liquid desiccant based cooling system.

  6. Colorado State University program for developing, testing, evaluating and optimizing solar heating and cooling systems. Project status report, March--November 1992

    SciTech Connect

    Not Available

    1993-01-07

    This program includes six tasks, including (1) a project measuring the performance of unique solar system components, (2) a project to develop a methodology for determining annual performance ratings of solar domestic hot water systems, (3) a project that will identify, analyze, design, build, and experimentally evaluate SDHW systems incorporating advanced concepts and components, (4) a liquid desiccant cooling system development project, (5) a project that will perform TRNSYS simulations to determine potential energy savings for desiccant cooling systems, especially in humid climates, and (6) a management task. The objectives and progress in each task are described.

  7. Colorado State University program for developing, testing, evaluating and optimizing solar heating and cooling systems

    SciTech Connect

    Not Available

    1991-10-28

    The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The SEAL-DOE program includes six tasks which have received funding for the 1991--92 fifteen-month period. These include: (1) a project employing isothermal operation of air and liquid solar space heating systems; (2) a project to build and test several generic solar water heaters; (3) a project that will evaluate advanced solar domestic hot water components and concepts and integrate them into solar domestic hot water systems; (4) a liquid desiccant cooling system development project; (5) a project that will perform system modeling and analysis work on solid desiccant cooling systems research; and (6) a management task. The objectives and progress in each task are described in this report. 6 figs.

  8. Solar Heating and Cooling: An Economic Assessment.

    ERIC Educational Resources Information Center

    McGarity, Arthur E.

    This study serves as an introduction to the important economic considerations that are necessary for an assessment of the potential for solar heating and cooling in the United States. The first chapter introduces the technology that is used to tap solar energy for residential and commercial applications and illustrates the potential significance…

  9. Moving Advanced Desiccant Materials into Mainstream Non-CFC Cooling Products

    SciTech Connect

    Sand, J. R.; Grossman, T.; Rice, C. K.; Fairchild, P. D.; Gross, I. L.

    2004-12-30

    Desiccant dehumidification technology is emerging as a technically viable alternative for comfort conditioning in many commercial and institutional buildings. Attempts to improve the indoor air quality of buildings has resulted in increasingly stringent guidelines for occupant outdoor air ventilation rates. Additionally, revised building heating, ventilating, and air-conditioning (HVAC) design criteria based on regional peak dew point data highlight the important of the latent (moisture removal) building load relative to the sensible (temperature) building load.

  10. Solar heating and cooling: Technical data and systems analysis

    NASA Technical Reports Server (NTRS)

    Christensen, D. L.

    1975-01-01

    The solar energy research is reported including climatic data, architectural data, heating and cooling equipment, thermal loads, and economic data. Lists of data sources presented include: selected data sources for solar energy heating and cooling; bibliography of solar energy, and other energy sources; sources for manufacturing and sales, solar energy collectors; and solar energy heating and cooling projects.

  11. Solar absorption cooling plant in Seville

    SciTech Connect

    Bermejo, Pablo; Pino, Francisco Javier; Rosa, Felipe

    2010-08-15

    A solar/gas cooling plant at the Engineering School of Seville (Spain) was tested during the period 2008-2009. The system is composed of a double-effect LiBr + water absorption chiller of 174 kW nominal cooling capacity, powered by: (1) a pressurized hot water flow delivered by mean of a 352 m{sup 2} solar field of a linear concentrating Fresnel collector and (2) a direct-fired natural gas burner. The objective of the project is to indentify design improvements for future plants and to serve as a guideline. We focused our attention on the solar collector size and dirtiness, climatology, piping heat losses, operation control and coupling between solar collector and chiller. The daily average Fresnel collector efficiency was 0.35 with a maximum of 0.4. The absorption chiller operated with a daily average coefficient of performance of 1.1-1.25, where the solar energy represented the 75% of generator's total heat input, and the solar cooling ratio (quotient between useful cooling and insolation incident on the solar field) was 0.44. (author)

  12. Desiccant Enhanced Evaporative Air-Conditioning (DEVap): Evaluation of a New Concept in Ultra Efficient Air Conditioning

    SciTech Connect

    Kozubal, E.; Woods, J.; Burch, J.; Boranian, A.; Merrigan, T.

    2011-01-01

    NREL has developed the novel concept of a desiccant enhanced evaporative air conditioner (DEVap) with the objective of combining the benefits of liquid desiccant and evaporative cooling technologies into an innovative 'cooling core.' Liquid desiccant technologies have extraordinary dehumidification potential, but require an efficient cooling sink. DEVap's thermodynamic potential overcomes many shortcomings of standard refrigeration-based direct expansion cooling. DEVap decouples cooling and dehumidification performance, which results in independent temperature and humidity control. The energy input is largely switched away from electricity to low-grade thermal energy that can be sourced from fuels such as natural gas, waste heat, solar, or biofuels.

  13. Prototype solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A collection of monthly status reports on the development of eight prototype solar heating and cooling systems is presented. The effort calls for the development, manufacture, test, system installation, maintenance, problem resolution, and performance evaluation. The systems are 3, 25, and 75 ton size units.

  14. Public policy for solar heating and cooling

    NASA Technical Reports Server (NTRS)

    Hirshberg, A. S.

    1976-01-01

    Recent analyses indicated that solar heating and cooling systems for residential buildings are nearly economically competitive with conventional fossil fuel or electric systems, the former having higher initial cost but a lower operating cost than the latter. The paper examines obstacles to the widespread acceptance and use of solar space conditioning systems and explores some general policies which could help to overcome them. The discussion covers such institutional barriers limiting the adoption of solar technologies as existing building codes, financing constraints, and organizational structure of the building industry. The potential impact of financial incentives is analyzed. It is noted that a tax incentive of 25% could speed the use of solar energy by 7 to 8 years and produce an 8% reduction in fossil fuel use by 1990. A preliminary incentive package which could be helpful in promoting solar energy both at federal and state levels is proposed, and the necessary incentive level is analysed.

  15. Solar-Cooled Hotel in the Virgin Islands

    NASA Technical Reports Server (NTRS)

    Harber, H.

    1982-01-01

    Performance of solar cooling system is described in 21-page report. System provides cooling for public areas including ball rooms, restaurant, lounge, lobby and shops. Chilled water from solar-cooling system is also used to cool hot water from hotel's desalinization plant.

  16. Adiabatic cooling of solar wind electrons

    NASA Technical Reports Server (NTRS)

    Sandbaek, Ornulf; Leer, Egil

    1992-01-01

    In thermally driven winds emanating from regions in the solar corona with base electron densities of n0 not less than 10 exp 8/cu cm, a substantial fraction of the heat conductive flux from the base is transfered into flow energy by the pressure gradient force. The adiabatic cooling of the electrons causes the electron temperature profile to fall off more rapidly than in heat conduction dominated flows. Alfven waves of solar origin, accelerating the basically thermally driven solar wind, lead to an increased mass flux and enhanced adiabatic cooling. The reduction in electron temperature may be significant also in the subsonic region of the flow and lead to a moderate increase of solar wind mass flux with increasing Alfven wave amplitude. In the solar wind model presented here the Alfven wave energy flux per unit mass is larger than that in models where the temperature in the subsonic flow is not reduced by the wave, and consequently the asymptotic flow speed is higher.

  17. Analysis of the adsorption process and of desiccant cooling systems: a pseudo- steady-state model for coupled heat and mass transfer. [DESSIM, DESSIM2, DESSIM4

    SciTech Connect

    Barlow, R.S.

    1982-12-01

    A computer model to simulate the adiabatic adsorption/desorption process is documented. Developed to predict the performance of desiccant cooling systems, the model has been validated through comparison with experimental data for single-blow adsorption and desorption. A literature review on adsorption analysis, detailed discussions of the adsorption process, and an initial assessment of the potential for performance improvement through advanced component development are included.

  18. Market potential for solar heating and cooling in buildings

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The use of solar heating and cooling for buildings as a method of conserving fossil fuels is discussed. The residential and commercial end use consumption of energy is tabulated. A survey to project the energy requirements for home and industry heating and cooling is developed. The survey indicates that there is a market potential for solar heating and cooling of buildings. A prediction of three to five billion dollars per year as the potential for solar heating and cooling is made.

  19. Storage and cooling by solar energy

    NASA Astrophysics Data System (ADS)

    Exell, R. H. B.

    1982-01-01

    Techniques for converting solar energy into mechanical energy for use in small-to-large scale refrigeration systems are examined. The systems considered included a Rankine cycle, 106 kW system coupled to 58 sq m of flat plate collectors, photovoltaic panels with storage in the form of ice, a positive ventilation and ice bank cooling system, ammonia-water absorption refrigeration, intermittent refrigeration, and solid adsorption refrigeration. All the equipment will be required to produce storage temperatures in the range 0-10 C and, consequently, the use of solar energy for deep freeze applications is considered unlikely. Small units which feature storage spaces of around one cubic meter can be satisfied by solar cells or intermittent absorption units. Larger-sized storage will employ the ammonia absorption process. Flat-plate collectors are foreseen to supply the power in rural areas.

  20. Solar Powered Liquid Desiccant Air Conditioner for Low-Electricity Humidity Control

    DTIC Science & Technology

    2012-07-01

    thermal comfort conditions. Liquid-desiccants are solutions that are hygroscopic but are easily able to be pumped and applied within heating, ventilating, and air conditioning (HVAC) equipment as necessary.

  1. Solar thermal heating and cooling. A bibliography with abstracts

    NASA Technical Reports Server (NTRS)

    Arenson, M.

    1979-01-01

    This bibliographic series cites and abstracts the literature and technical papers on the heating and cooling of buildings with solar thermal energy. Over 650 citations are arranged in the following categories: space heating and cooling systems; space heating and cooling models; building energy conservation; architectural considerations, thermal load computations; thermal load measurements, domestic hot water, solar and atmospheric radiation, swimming pools; and economics.

  2. Potential of solar cooling systems for peak demand reduction

    SciTech Connect

    Pesaran, A A; Neymark, J

    1994-11-01

    We investigated the technical feasibility of solar cooling for peak demand reduction using a building energy simulation program (DOE2.1D). The system studied was an absorption cooling system with a thermal coefficient of performance of 0.8 driven by a solar collector system with an efficiency of 50% with no thermal storage. The analysis for three different climates showed that, on the day with peak cooling load, about 17% of the peak load could be met satisfactorily with the solar-assisted cooling system without any thermal storage. A performance availability analysis indicated that the solar cooling system should be designed for lower amounts of available solar resources that coincide with the hours during which peak demand reduction is required. The analysis indicated that in dry climates, direct-normal concentrating collectors work well for solar cooling; however, in humid climates, collectors that absorb diffuse radiation work better.

  3. Solar heating and cooling systems design and development

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The development and delivery of eight prototype solar heating and cooling systems for installation and operational test was reported. Two heating and six heating and cooling units will be delivered for single family residences, multiple family residences and commercial applications.

  4. Liquid cooled, linear focus solar cell receiver

    DOEpatents

    Kirpich, A.S.

    1983-12-08

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  5. Liquid cooled, linear focus solar cell receiver

    DOEpatents

    Kirpich, Aaron S.

    1985-01-01

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  6. Prototype solar heating and combined heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Eight prototype solar heating and combined heating and cooling systems are being developed. The effort includes development, manufacture, test, installation, maintenance, problem resolution, and performance evaluation.

  7. Prototype solar heating and combined heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Eight prototype solar heating and combined heating and cooling systems are considered. This effort includes development, manufacture, test, installation, maintenance, problem resolution, and performance evaluation.

  8. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress made in the manufacture, test, evaluation, installation, problem resolution, performance evaluation, and development of eight prototype solar heating and combined heating and cooling systems is described.

  9. Solar heating and cooling systems design and development

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Solar heating and heating/cooling systems were designed for single family, multifamily, and commercial applications. Subsystems considered included solar collectors, heat storage systems, auxiliary energy sources, working fluids, and supplementary controls, piping, and pumps.

  10. Technical use of solar energy: Conversion from solar to thermal energy, solar cooling and thermal energy storage

    NASA Astrophysics Data System (ADS)

    Arafa, A.; Fisch, N.; Hahne, E.; Kraus, K.; Seemann, D.; Seifert, B.; Sohns, J.; Schetter, G.; Schweigerer, W.

    1983-12-01

    Experimental and theoretical studies in the field of solar energy utilization are reviewed. Specific topics considered are: flat plate water collectors, solar absorbers, air collectors, solar absorption cooling, solar simulators, aquifiers, latent heat stores, and space heating systems.

  11. Prototype solar heating and combined heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Schedules and technical progress in the development of eight prototype solar heating and combined solar heating and cooling systems are reported. Particular emphasis is given to the analysis and preliminary design for the cooling subsystem, and the setup and testing of a horizontal thermal energy storage tank configuration and collector shroud evaluation.

  12. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The development of eight prototype solar heating and combined heating and cooling systems is reported. Manufacture, test, installation, maintenance, problem resolution, and monitoring the operation of prototype systems is included. Heating and cooling equipment for single family residential and commercial applications and eight operational test sites (four heating and four heating and cooling) is described.

  13. Cooling-load implications for residential passive solar heating systems

    NASA Astrophysics Data System (ADS)

    Jones, R. W.; McFarland, R. D.

    1983-11-01

    The quantification of cooling loads in residential buildings, particularly buildings with passive solar heating systems, is described, along with the computer simulation model used for calculating cooling loads. A sample of interim results is also presented. The objective of the research is to develop a simple analysis method, useful early in the design, to estimate the annual cooling energy requirement of a given building.

  14. Performance Analysis of XCPC Powered Solar Cooling Demonstration Project

    NASA Astrophysics Data System (ADS)

    Widyolar, Bennett K.

    A solar thermal cooling system using novel non-tracking External Compound Parabolic Concentrators (XCPC) has been built at the University of California, Merced and operated for two cooling seasons. Its performance in providing power for space cooling has been analyzed. This solar cooling system is comprised of 53.3 m2 of XCPC trough collectors which are used to power a 23 kW double effect (LiBr) absorption chiller. This is the first system that combines both XCPC and absorption chilling technologies. Performance of the system was measured in both sunny and cloudy conditions, with both clean and dirty collectors. It was found that these collectors are well suited at providing thermal power to drive absorption cooling systems and that both the coinciding of available thermal power with cooling demand and the simplicity of the XCPC collectors compared to other solar thermal collectors makes them a highly attractive candidate for cooling projects.

  15. Low-Flow Liquid Desiccant Air-Conditioning: Demonstrated Performance and Cost Implications

    SciTech Connect

    Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.; Lowenstein, A.

    2014-09-01

    Cooling loads must be dramatically reduced when designing net-zero energy buildings or other highly efficient facilities. Advances in this area have focused primarily on reducing a building's sensible cooling loads by improving the envelope, integrating properly sized daylighting systems, adding exterior solar shading devices, and reducing internal heat gains. As sensible loads decrease, however, latent loads remain relatively constant, and thus become a greater fraction of the overall cooling requirement in highly efficient building designs, particularly in humid climates. This shift toward latent cooling is a challenge for heating, ventilation, and air-conditioning (HVAC) systems. Traditional systems typically dehumidify by first overcooling air below the dew-point temperature and then reheating it to an appropriate supply temperature, which requires an excessive amount of energy. Another dehumidification strategy incorporates solid desiccant rotors that remove water from air more efficiently; however, these systems are large and increase fan energy consumption due to the increased airside pressure drop of solid desiccant rotors. A third dehumidification strategy involves high flow liquid desiccant systems. These systems require a high maintenance separator to protect the air distribution system from corrosive desiccant droplet carryover and so are more commonly used in industrial applications and rarely in commercial buildings. Both solid desiccant systems and most high-flow liquid desiccant systems (if not internally cooled) add sensible energy which must later be removed to the air stream during dehumidification, through the release of sensible heat during the sorption process.

  16. Preliminary design package for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Summarized preliminary design information on activities associated with the development, delivery and support of solar heating and cooling systems is given. These systems are for single family dwellings and commercial applications. The heating/cooling system use a reversible vapor compression heat pump that is driven in the cooling mode by a Rankine power loop, and in the heating mode by a variable speed electric motor. The heating/cooling systems differ from the heating-only systems in the arrangement of the heat pump subsystem and the addition of a cooling tower to provide the heat sink for cooling mode operation.

  17. Solar air-conditioning-active, hybrid and passive

    SciTech Connect

    Yellott, J. I.

    1981-04-01

    After a discussion of summer air conditioning requirements in the United States, active, hybrid, and passive cooling systems are defined. Active processes and systems include absorption, Rankine cycle, and a small variety of miscellaneous systems. The hybrid solar cooling and dehumidification technology of desiccation is covered as well as evaporative cooling. The passive solar cooling processes covered include convective, radiative and evaporative cooling. Federal and state involvement in solar cooling is then discussed. (LEW)

  18. Solar heating and cooling diode module

    DOEpatents

    Maloney, Timothy J.

    1986-01-01

    A high efficiency solar heating system comprising a plurality of hollow modular units each for receiving a thermal storage mass, the units being arranged in stacked relation in the exterior frame of a building, each of the units including a port for filling the unit with the mass, a collector region and a storage region, each region having inner and outer walls, the outer wall of the collector region being oriented for exposure to sunlight for heating the thermal storage mass; the storage region having an opening therein and the collector region having a corresponding opening, the openings being joined for communicating the thermal storage mass between the storage and collector regions by thermosiphoning; the collector region being disposed substantially below and in parallel relation to the storage region in the modular unit; and the inner wall of the collector region of each successive modular unit in the stacked relation extending over the outer wall of the storage region of the next lower modular unit in the stacked relation for reducing heat loss from the system. Various modifications and alternatives are disclosed for both heating and cooling applications.

  19. Prototype solar heating and combined heating cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The design and development of eight prototype solar heating and combined heating and cooling systems is discussed. The program management and systems engineering are reported, and operational test sites are identified.

  20. Solar heating and cooling technical data and systems analysis

    NASA Technical Reports Server (NTRS)

    Christensen, D. L.

    1977-01-01

    The research activities described herein were concentrated on the areas of economics, heating and cooling systems, architectural design, materials characteristics, climatic conditions, educational information packages, and evaluation of solar energy systems and components.

  1. Preliminary design activities for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information on the development of solar heating and cooling systems is presented. The major emphasis is placed on program organization, system size definition, site identification, system approaches, heat pump and equipment design, collector procurement, and other preliminary design activities.

  2. Solar heating and cooling systems design and development

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Progress in the development of prototype solar heating/cooling systems is reported. Results obtained from refinement/improvement of the single family, multifamily, and commercial systems configurations and generalized studies on several of the subsystems are presented.

  3. Solar residential heating and cooling system development test program

    NASA Technical Reports Server (NTRS)

    Humphries, W. R.; Melton, D. E.

    1974-01-01

    A solar heating and cooling system is described, which was installed in a simulated home at Marshall Space Flight Center. Performance data are provided for the checkout and initial operational phase for key subsystems and for the total system. Valuable information was obtained with regard to operation of a solar cooling system during the first summer of operation. Areas where improvements and modifications are required to optimize such a system are discussed.

  4. Solar heating and cooling systems design and development. [prototype development

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The development of twelve prototype solar heating/cooling systems, six heating and six heating and cooling systems, two each for single family, multi-family, and commercial applications, is reported. Schedules and technical discussions, along with illustrations on the progress made from April 1, 1977 through June 30, 1977 are detailed.

  5. Passive thermosyphon solar heating and cooling module with supplementary heating

    NASA Technical Reports Server (NTRS)

    1977-01-01

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

  6. Convective Array Cooling for a Solar Powered Aircraft

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Dolce, James (Technical Monitor)

    2003-01-01

    A general characteristic of photovoltaics is that they increase in efficiency as their operating temperature decreases. Based on this principal, the ability to increase a solar aircraft's performance by cooling the solar cells was examined. The solar cells were cooled by channeling some air underneath the cells and providing a convective cooling path to the back side of the array. A full energy balance and flow analysis of the air within the cooling passage was performed. The analysis was first performed on a preliminary level to estimate the benefits of the cooling passage. This analysis established a clear benefit to the cooling passage. Based on these results a more detailed analysis was performed. From this cell temperatures were calculated and array output power throughout a day period were determined with and without the cooling passage. The results showed that if the flow through the cooling passage remained laminar then the benefit in increased output power more than offset the drag induced by the cooling passage.

  7. SERI Desiccant Cooling Test Facility. Status report. Preliminary data on the performance of a rotary parallel-passage silica-gel dehumidifier

    SciTech Connect

    Schultz, K.J.

    1986-04-01

    This report describes the SERI Desiccant Cooling Test Facility. The facility can test bench-scale rotary dehumidifiers over a wide range of controlled conditions. We constructed and installed in the test loop a prototype parallel-passage rotary dehumidifier that has spirally wound polyester tape coated with silica gel. The initial tests gave satisfactory results indicating that approximately 90% of the silica gel was active and the overall Lewis number of the wheel was near unity. The facility has several minor difficulties including an inability to control humidity satisfactorily and nonuniform and highly turbulent inlet velocities. To completely validate the facility requires a range of dehumidifier designs. Several choices are available including constructing a second parallel-passage dehumidifier with the passage spacing more uniform.

  8. Solar powered dehumidifier apparatus

    DOEpatents

    Jebens, Robert W.

    1980-12-30

    A thermally insulated light transmitting housing forms a chamber containing a desiccant and having a first gas port open to the ambient and a second gas port connected by a two way valve to a volume to be dried. Solar energy transmitted through the housing heats and dries the desiccant. The increased air pressure due to the heating of the volume to be dried causes the air from the volume to be expelled through the valve into the chamber. The desiccant is then cooled by shielding it from solar energy before the volume cools thereby increasing its moisture absorbing capacity. Then the volume is allowed to cool drawing dehumidified air through the desiccant and the valve into the volume to be dried. This cycle is then repeated.

  9. Inhibitor analysis for a solar heating and cooling system

    NASA Technical Reports Server (NTRS)

    Tabony, J. H.

    1977-01-01

    A study of potential corrosion inhibitors for the NASA solar heating and cooling system which uses aluminum solar panels is provided. Research consisted of testing using a dynamic corrosion system, along with an economic analysis of proposed corrosion inhibitors. Very good progress was made in finding a suitable inhibitor for the system.

  10. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The design and development of marketable solar heating and cooling systems for single family and commercial applications is described. The delivery, installation, and monitoring of the prototype systems are discussed. Seven operational test sites are discussed in terms of system performance. Problems encountered with equipment and installation were usually due to lack of skills required for solar system installation.

  11. Preliminary design package for prototype solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A summary is given of the preliminary analysis and design activity on solar heating and cooling systems. The analysis was made without site specific data other than weather; therefore, the results indicate performance expected under these special conditions. Major items include a market analysis, design approaches, trade studies and other special data required to evaluate the preliminary analysis and design. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test. Two heating and six heating and cooling units will be delivered for Single Family Residences, Multiple-family Residences and commercial applications.

  12. Solar cooling system performance, Frenchman's Reef Hotel, Virgin Islands

    NASA Technical Reports Server (NTRS)

    Harber, H.

    1981-01-01

    The operational and thermal performance of a variety of solar systems are described. The Solar Cooling System was installed in a hotel at St. Thomas, U. S. Virgin Islands. The system consists of the evacuated glass tube collectors, two 2500 gallon tanks, pumps, computerized controller, a large solar optimized industrial sized lithium bromide absorption chiller, and associated plumbing. Solar heated water is pumped through the system to the designed public areas such as lobby, lounges, restaurant and hallways. Auxiliary heat is provided by steam and a heat exchanger to supplement the solar heat.

  13. Solar cooling system performance, Frenchman's Reef Hotel, Virgin Islands

    NASA Astrophysics Data System (ADS)

    Harber, H.

    1981-09-01

    The operational and thermal performance of a variety of solar systems are described. The Solar Cooling System was installed in a hotel at St. Thomas, U. S. Virgin Islands. The system consists of the evacuated glass tube collectors, two 2500 gallon tanks, pumps, computerized controller, a large solar optimized industrial sized lithium bromide absorption chiller, and associated plumbing. Solar heated water is pumped through the system to the designed public areas such as lobby, lounges, restaurant and hallways. Auxiliary heat is provided by steam and a heat exchanger to supplement the solar heat.

  14. Performance assessment and transient optimization of multi-stage solid desiccant air conditioning systems with building PV/T integration

    NASA Astrophysics Data System (ADS)

    Gadalla, Mohamed; Saghafifar, Mohammad

    2016-09-01

    One of the popular solar air conditioning technologies is desiccant air conditioning. Nonetheless, single stage desiccant air conditioning systems' coefficient of performance (COP) are relatively low. Therefore, multi-stage solid desiccant air conditioning systems are recommended. In this paper, an integrated double-stage desiccant air conditioning systems and PV/T collector is suggested for hot and humid climates such as the UAE. The results for the PV/T implementation in the double-stage desiccant cooling system are assessed against the PV/T results for a single-stage desiccant air conditioning system. In order to provide a valid comparative evaluation between the single and double stage desiccant air conditioning systems, an identical PV/T module, in terms of dimensions, is incorporated into these systems. The overall required auxiliary air heating is abated by 46.0% from 386.8 MWh to 209.0 MWh by replacing the single stage desiccant air conditioning system with the proposed double stage configuration during June to October. Moreover, the overall averaged solar share during the investigated months for the single and double stage systems are 36.5% and 43.3%.

  15. Solar-heating and cooling demonstration project

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Florida Solar Energy Center has retrofitted office building, approximately 5,000 square feet of area, with solar heating and air-conditioning. Information on operation, installation, controls, and hardware for system is contained in 164 page report. Document includes manufacturer's product literature and detailed drawings.

  16. Solar heating and cooling system installed at Leavenworth, Kansas

    NASA Technical Reports Server (NTRS)

    1980-01-01

    A solar heating and cooling is described which is designed to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2,200 square feet. Five 3 ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3,000 gallon chilled water storage tank. Two 3,000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

  17. Solar heating and cooling system installed at Leavenworth, Kansas

    NASA Astrophysics Data System (ADS)

    1980-06-01

    A solar heating and cooling is described which is designed to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2,200 square feet. Five 3 ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3,000 gallon chilled water storage tank. Two 3,000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

  18. Composite desiccant structure

    DOEpatents

    Fraioli, Anthony V.; Schertz, William W.

    1987-01-01

    A composite formed of small desiccant particles retained in a dark matrix composed of a porous binder containing a transition metal oxide with pores to provide moisture transport with respect to the particles, and metallic fibers to remove the heat of condensation during dehumidification and provide heat for the removal of moisture during regeneration. The moisture absorbing properties of the composite may be regenerated by exposure of the dark matrix to solar radiation with dehumidification occurring at night.

  19. Composite desiccant structure

    DOEpatents

    Fraioli, A.V.; Schertz, W.W.

    1984-06-06

    This patent discloses a composite formed of small desiccant particles retained in a dark matrix composed of a porous binder containing a transition metal oxide with pores to provide moisture transport with respect to the particles, and metallic fibers to remove the heat of condensation during dehumidification and provide heat for the removal of moisture during regeneration. The moisture absorbing properties of the composite may be regenerated by exposure of the dark matrix to solar radiation with dehumidification occurring at night.

  20. Solar heating and cooling technical data and systems analysis

    NASA Technical Reports Server (NTRS)

    Christensen, D. L.

    1976-01-01

    The acquisition and processing of selected parametric data for inclusion in a computerized Data Base using the Marshall Information Retrieval and Data System (MIRADS) developed by NASA-MSFC is discussed. This data base provides extensive technical and socioeconomic information related to solar energy heating and cooling on a national scale. A broadly based research approach was used to assist in the support of program management and the application of a cost-effective program for solar energy development and demonstration.

  1. Solar-Heated and Cooled Office Building--Columbus, Ohio

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Final report documents solar-energy system installed in office building to provide space heating, space cooling and domestic hot water. Collectors mounted on roof track Sun and concentrate rays on fluid-circulating tubes. Collected energy is distributed to hot-water-fired absorption chiller and space-heating and domestic-hot-water preheating systems.

  2. The development of a solar residential heating and cooling system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The MSFC solar heating and cooling facility was assembled to demonstrate the engineering feasibility of utilizing solar energy for heating and cooling buildings, to provide an engineering evaluation of the total system and the key subsystems, and to investigate areas of possible improvement in design and efficiency. The basic solar heating and cooling system utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating, and an absorption cycle air conditioner for space cooling. A complete description of all systems is given. Development activities for this test system included assembly, checkout, operation, modification, and data analysis, all of which are discussed. Selected data analyses for the first 15 weeks of testing are included, findings associated with energy storage and the energy storage system are outlined, and conclusions resulting from test findings are provided. An evaluation of the data for summer operation indicates that the current system is capable of supplying an average of 50 percent of the thermal energy required to drive the air conditioner. Preliminary evaluation of data collected for operation in the heating mode during the winter indicates that nearly 100 percent of the thermal energy required for heating can be supplied by the system.

  3. Corrosion inhibitors for solar-heating and cooling

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1979-01-01

    Report describes results of tests conducted to evaluate abilities of 12 candidate corrosion inhibitors to protect aluminum, steel, copper, or stainless steel at typical conditions encountered in solar heating and cooling systems. Inhibitors are based on sodium salts including nitrates, borates, silicates, and phosphates.

  4. Prototype solar heating and cooling systems including potable hot water

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress is reviewed in the development, delivery, and support of two prototype solar heating and cooling systems including potable hot water. The system consisted of the following subsystems: collector, auxiliary heating, potable hot water, storage, control, transport, and government-furnished site data acquisition.

  5. Solar Heating and Cooling of Residential Buildings: Design of Systems.

    ERIC Educational Resources Information Center

    Colorado State Univ., Ft. Collins. Solar Energy Applications Lab.

    This is the second of two training courses designed to develop the capability of practitioners in the home building industry to design solar heating and cooling systems. The course is organized in 23 modules to separate selected topics and to facilitate learning. Although a compact schedule of one week is shown, a variety of formats can be…

  6. International Energy Agency Solar Heating and Cooling Program

    NASA Astrophysics Data System (ADS)

    Brooks, A. J.

    This trip was undertaken to participate in and represent the United States Industry at the International Energy Agency (IEA) Solar Heating and Cooling Program (SHCP) Task 14 Workshop. The meeting took place at the A1 Bani Hotel in Rome Italy.

  7. Keeping Cool With Solar-Powered Refrigeration

    NASA Technical Reports Server (NTRS)

    2003-01-01

    In the midst of developing battery-free, solar-powered refrigeration and air conditioning systems for habitats in space, David Bergeron, the team leader for NASA's Advanced Refrigerator Technology Team at Johnson Space Center, acknowledged the need for a comparable solar refrigerator that could operate in conjunction with the simple lighting systems already in place on Earth. Bergeron, a 20-year veteran in the aerospace industry, founded the company Solus Refrigeration, Inc., in 1999 to take the patented advanced refrigeration technology he co-developed with his teammate, Johnson engineer Michael Ewert, to commercial markets. Now known as SunDanzer Refrigeration, Inc., Bergeron's company is producing battery-free, photovoltaic (PV) refrigeration systems under license to NASA, and selling them globally.

  8. Solar atrium: A hybrid solar heating and cooling system

    NASA Astrophysics Data System (ADS)

    Ueland, M.

    1980-06-01

    The atrium is designed to be constructed of materials and equipment that are economical and readily available. Cost effectiveness of installation and operation is a primary design objective. The solar atrium is a further development of efforts begun in the 1930's and 1940's to design houses that would obtain a major portion of their heating from the Sun. The early solar house experiments proved the benefits of large glazed areas for trapping solar energy. However, they were not equipped to collect and store surplus solar energy, nor were they equipped to control heat losses through glass areas at night or during cloudy days. The solar atrium incorporates the large glass areas of the earlier houses and adds facilities for heat storage and control of heat losses through glass. Progress and plans are outlined.

  9. Active solar heating and cooling information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-01-01

    The results of a series of telephone interviews with groups of users of information on active solar heating and cooling (SHAC). An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from 19 SHAC groups respondents are analyzed in this report: DOE-Funded Researchers, Non-DOE-Funded Researchers, Representatives of Manufacturers (4 groups), Distributors, Installers, Architects, Builders, Planners, Engineers (2 groups), Representatives of Utilities, Educators, Cooperative Extension Service County Agents, Building Owners/Managers, and Homeowners (2 groups). The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  10. Solar-powered Rankine heat pump for heating and cooling

    NASA Technical Reports Server (NTRS)

    Rousseau, J.

    1978-01-01

    The design, operation and performance of a familyy of solar heating and cooling systems are discussed. The systems feature a reversible heat pump operating with R-11 as the working fluid and using a motor-driven centrifugal compressor. In the cooling mode, solar energy provides the heat source for a Rankine power loop. The system is operational with heat source temperatures ranging from 155 to 220 F; the estimated coefficient of performance is 0.7. In the heating mode, the vapor-cycle heat pump processes solar energy collected at low temperatures (40 to 80 F). The speed of the compressor can be adjusted so that the heat pump capacity matches the load, allowing a seasonal coefficient of performance of about 8 to be attained.

  11. Solar heating and cooling demonstration project at the Florida solar energy center

    NASA Astrophysics Data System (ADS)

    1980-02-01

    The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. The system was designed to supply approximately 70 percent of the annual cooling and 100 percent of the heating load. The project provides unique high temperature, nonimaging, nontracking, evacuated tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection. Information is provided on the system's acceptance test results operation, controls, hardware and installation, including detailed drawings.

  12. Solar heating and cooling demonstration project at the Florida solar energy center

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. The system was designed to supply approximately 70 percent of the annual cooling and 100 percent of the heating load. The project provides unique high temperature, nonimaging, nontracking, evacuated tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection. Information is provided on the system's acceptance test results operation, controls, hardware and installation, including detailed drawings.

  13. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The progress of the program during the sixth program quarter is reported. The program calls for the development and delivery of eight prototype solar heating and cooling systems for installation and operational test. The William O'Brien single-family heating system was installed and is operational. The New Castle single-family heating residence is under construction. The Kansas University (KU) system is in the final design stages. The 25 ton cooling subsystem for KU is the debugging stage. Pressure drops that were greater than anticipated were encountered. The 3 ton simulation work is being finalized and the design parameters for the Rankine system were determined from simulation output.

  14. Solar Cooling for Buildings. Workshop Proceedings (Los Angeles, California, February 6-8, 1974).

    ERIC Educational Resources Information Center

    de Winter, Francis, Ed.

    A consensus has developed among U.S. solar researchers that the solar-powered cooling of buildings is an important topic. Most solar heating systems are technically simpler, and more highly developed, than solar cooling devices are. The determination of the best design concept for any particular application is not a simple process. Significant…

  15. Solar heating and cooling system installed at Columbus, Ohio

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The Solar Energy System was installed as a part of a new construction of a college building. The building will house classrooms and laboratories, administrative offices and three lecture halls. The Solar Energy System consists of 4,096 square feet (128 panels) Owens/Illinois Evacuated Glass Tube Collector Subsystem, and a 5,000 gallon steel tank below ground storage system. Hot water is circulated between the collectors and storage tank, passing through a water/lithium bromide absorption chiller to cool the building.

  16. Concerning the improvement of solar heating and cooling systems

    NASA Astrophysics Data System (ADS)

    Rashidov, Iu. K.

    It is suggested that systems of solar heating and cooling can be simplified by the use of 'organized hydrothermal processes' (OHP) in the elements (e.g., circulation systems and heat storage units) of such systems. This paper defines and classifies such processes. Design diagrams are presented for two types of systems: (1) a heating, hot-water, and storage system with one-phase OHPs; and (2) a gravity-assisted heat pipe and an adsorption-type solar refrigeration system with two-phase OHPs.

  17. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.; Deramus, G. E., Jr.

    1977-01-01

    Problems dealing with corrosion and corrosion protection of solar heating and cooling systems are discussed. A test program was conducted to find suitable and effective corrosion inhibitors for systems employing either water or antifreeze solutions for heat transfer and storage. Aluminum-mild-steel-copper-stainless steel assemblies in electrical contact were used to simulate a multimetallic system which is the type most likely to be employed. Several inhibitors show promise for this application.

  18. Heat transfer to the adsorbent in solar adsorption cooling device

    NASA Astrophysics Data System (ADS)

    Pilat, Peter; Patsch, Marek; Papucik, Stefan; Vantuch, Martin

    2014-08-01

    The article deals with design and construction of solar adsorption cooling device and with heat transfer problem in adsorber. The most important part of adsorption cooling system is adsorber/desorber containing adsorbent. Zeolith (adsorbent) type was chosen for its high adsorption capacity, like a coolant was used water. In adsorber/desorber occur, at heating of adsorbent, to heat transfer from heat change medium to the adsorbent. The time required for heating of adsorber filling is very important, because on it depend flexibility of cooling system. Zeolith has a large thermal resistance, therefore it had to be adapted the design and construction of adsorber. As the best shows the tube type of adsorber with double coat construction. By this construction is ensured thin layer of adsorbent and heating is quick in all volume of adsorbent. The process of heat transfer was experimentally measured, but for comparison simulated in ANSYS, too.

  19. Developing, testing, evaluating and optimizing solar heating and cooling systems

    NASA Astrophysics Data System (ADS)

    Karaki, S.

    1989-05-01

    The objective is to develop and test various integrated solar heating, cooling and domestic hot water systems, and to evaluate their performance. Systems composed of new, as well as previously tested, components are carefully integrated so that effects of new components on system performance can be clearly delineated. The program for 1989-90 is separated into seven tasks. There are asks for each of the three solar houses, a project to build and test several generic solar water heaters, a task involving development of an improved evacuated tube collector, a management task, and a task under which an international workshop will test IEA Task 4 models. The objectives and progress in each task are described in this report.

  20. Solar heating and cooling demonstration project at the Florida Solar Energy Center

    SciTech Connect

    Hankins, J.D.

    1980-02-01

    The retrofitted solar heating and cooling system installed at the Florida Solar Energy Center is described. Information is provided on the system's test, operation, controls, hardware and installation, including detailed drawings. The Center's office building, approximately 5000 square feet of space, with solar air conditioning and heating as a demonstration of the technical feasibility is located just north of Port Canaveral, Florida. The system was designed to supply approximately 70% of the annual cooling and 100% of the heating load. The project provides unique high-temperature, non-imaging, non-tracking, evacuated-tube collectors. The design of the system was kept simple and employs five hydronic loops. They are energy collection, chilled water production, space cooling, space heating and energy rejection.

  1. Citywide Impacts of Cool Roof and Rooftop Solar Photovoltaic Deployment on Near-Surface Air Temperature and Cooling Energy Demand

    NASA Astrophysics Data System (ADS)

    Salamanca, F.; Georgescu, M.; Mahalov, A.; Moustaoui, M.; Martilli, A.

    2016-10-01

    Assessment of mitigation strategies that combat global warming, urban heat islands (UHIs), and urban energy demand can be crucial for urban planners and energy providers, especially for hot, semi-arid urban environments where summertime cooling demands are excessive. Within this context, summertime regional impacts of cool roof and rooftop solar photovoltaic deployment on near-surface air temperature and cooling energy demand are examined for the two major USA cities of Arizona: Phoenix and Tucson. A detailed physics-based parametrization of solar photovoltaic panels is developed and implemented in a multilayer building energy model that is fully coupled to the Weather Research and Forecasting mesoscale numerical model. We conduct a suite of sensitivity experiments (with different coverage rates of cool roof and rooftop solar photovoltaic deployment) for a 10-day clear-sky extreme heat period over the Phoenix and Tucson metropolitan areas at high spatial resolution (1-km horizontal grid spacing). Results show that deployment of cool roofs and rooftop solar photovoltaic panels reduce near-surface air temperature across the diurnal cycle and decrease daily citywide cooling energy demand. During the day, cool roofs are more effective at cooling than rooftop solar photovoltaic systems, but during the night, solar panels are more efficient at reducing the UHI effect. For the maximum coverage rate deployment, cool roofs reduced daily citywide cooling energy demand by 13-14 %, while rooftop solar photovoltaic panels by 8-11 % (without considering the additional savings derived from their electricity production). The results presented here demonstrate that deployment of both roofing technologies have multiple benefits for the urban environment, while solar photovoltaic panels add additional value because they reduce the dependence on fossil fuel consumption for electricity generation.

  2. Solar heating and cooling of residential buildings: sizing, installation and operation of systems. 1980 edition

    SciTech Connect

    1980-09-01

    This manual was prepared as a text for a training course on solar heating and cooling of residential buildings. The course and text are directed toward sizing, installation, operation, and maintenance of solar systems for space heating and hot water supply, and solar cooling is treated only briefly. (MHR)

  3. Quantum-radiative cooling for solar cells with textured surface

    NASA Astrophysics Data System (ADS)

    Gilman, Boris; Ivanov, Igor

    2004-11-01

    Efficient technique of Quantum Radiative Cooling (QRC) of textured Solar Cells and Modules is described that is capable of Solar Module (SM) temperature reduction by 5-20C, resulting in 3-10% efficiency increase. Novel methods are based on the quantum assisted IR emission from the surface covered by either multi-layer coatings made of Si-nitride, SiO or Si oxy-nitride films or specifically designed insulating sun-transparent chamber (QRC zone) that contains Selective Emissive (SE) gas or gas mix. QRC zone is mounted on the top of Solar Module replacing existing lamination coatings. To enhance the efficiency of QRC some specific methods and fabrication procedures are proposed to form an electricly charged textured surface that provide a high Electric Field at the surface thus enhancing IR emissivity from the surface. Such procedure can be also used to form the field Induced Surface Barriers in the Si-based Solar Cells that can substitute the existing diffused Emitters resulting in significant reduction of the Cycle Time as well as prospective Fabrication Cost.

  4. Site-dependent factors affecting the economic feasibility of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1977-01-01

    A procedure has been developed which can be used to determine the economic feasibility of solar powered absorption cooling systems. This procedure has been used in a study to investigate the influence of the site-dependent parameters on the economic feasibility of solar absorption cooling. The purpose of this study was to make preliminary site selections for solar powered absorption cooling systems. This paper summarizes the results of that study.

  5. Solar-powered saline sorbent-solution heat pump/storage system. [Coastal Energy Laboratory-Chemical Heat Pump (CEL-CHEAP)

    SciTech Connect

    Robison, H.; Houston, S.

    1981-01-01

    Coastal Energy Laboratory Chemical Heat Pump (CEL-CHEAP) is a redesigned open-cycle liquid desiccant air conditioner. Heat is discharged to shallow-well water by dehumidification-humidification for cooling and extracted by humidification-dehumidification for heating. Direct solar radiation concentrates the desiccant. For continuous operation, a small uninsulated tank stores concentrated solution. 6 refs.

  6. Small Scale Solar Cooling Unit in Climate Conditions of Latvia: Environmental and Economical Aspects

    NASA Astrophysics Data System (ADS)

    Jaunzems, Dzintars; Veidenbergs, Ivars

    2010-01-01

    The paper contributes to the analyses from the environmental and economical point of view of small scale solar cooling system in climate conditions of Latvia. Cost analyses show that buildings with a higher cooling load and full load hours have lower costs. For high internal gains, cooling costs are around 1,7 €/kWh and 2,5 €/kWh for buildings with lower internal gains. Despite the fact that solar cooling systems have significant potential to reduce CO2 emissions due to a reduction of electricity consumption, the economic feasibility and attractiveness of solar cooling system is still low.

  7. Influence of solar variability on the infrared radiative cooling of the thermosphere from 2002 to 2014

    PubMed Central

    Mlynczak, Martin G; Hunt, Linda A; Mertens, Christopher J; Thomas Marshall, B; Russell, James M; Woods, Thomas; Earl Thompson, R; Gordley, Larry L

    2014-01-01

    Infrared radiative cooling of the thermosphere by carbon dioxide (CO2, 15 µm) and by nitric oxide (NO, 5.3 µm) has been observed for 12 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite. For the first time we present a record of the two most important thermospheric infrared cooling agents over a complete solar cycle. SABER has documented dramatic variability in the radiative cooling on time scales ranging from days to the 11 year solar cycle. Deep minima in global mean vertical profiles of radiative cooling are observed in 2008–2009. Current solar maximum conditions, evidenced in the rates of radiative cooling, are substantially weaker than prior maximum conditions in 2002–2003. The observed changes in thermospheric cooling correlate well with changes in solar ultraviolet irradiance and geomagnetic activity during the prior maximum conditions. NO and CO2 combine to emit 7 × 1018 more Joules annually at solar maximum than at solar minimum. Key Points First record of thermospheric IR cooling rates over a complete solar cycleIR cooling in current solar maximum conditions much weaker than prior maximumVariability in thermospheric IR cooling observed on scale of days to 11 years PMID:26074647

  8. Liquid flat plate collector and pump for solar heating and cooling systems: A collection of quarterly reports

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress in the development, fabrication, and delivery of solar subsystems consisting of a solar operated pump, and solar collectors which can be used in solar heating and cooling, or hot water, for single family, multifamily, or commercial applications is reported.

  9. Solar Heating and Cooling of Residential Buildings: Sizing, Installation and Operation of Systems.

    ERIC Educational Resources Information Center

    Colorado State Univ., Ft. Collins. Solar Energy Applications Lab.

    This training course and a companion course titled "Design of Systems for Solar Heating and Cooling of Residential Buildings," are designed to train home designers and builders in the fundamentals of solar hydronic and air systems for space heating and cooling and domestic hot water heating for residential buildings. Each course, organized in 22…

  10. Solar Heating and Cooling of Buildings: Phase 0. Executive Summary. Final Report.

    ERIC Educational Resources Information Center

    Westinghouse Electric Corp., Baltimore, MD.

    After the Westinghouse Electric Corporation made a comprehensive analysis of the technical, economic, social, environmental, and institutional factors affecting the feasibility of utilizing solar energy for heating and cooling buildings, it determined that solar heating and cooling systems can become competitive in most regions of the country in…

  11. System design package for a solar heating and cooling system installed at Akron, Ohio

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Information used to evaluate the design of a solar heating, cooling, and domestic hot water system is given. A conventional heat pump provides summer cooling items as the design data brochure, system performance specification, system hazard analysis, spare parts list, and detailed design drawings. A solar system is installed in a single-family dwelling at Akron, Ohio, and at Duffield, Virginia.

  12. Optimum hot water temperature for absorption solar cooling

    SciTech Connect

    Lecuona, A.; Ventas, R.; Venegas, M.; Salgado, R.; Zacarias, A.

    2009-10-15

    The hot water temperature that maximizes the overall instantaneous efficiency of a solar cooling facility is determined. A modified characteristic equation model is used and applied to single-effect lithium bromide-water absorption chillers. This model is based on the characteristic temperature difference and serves to empirically calculate the performance of real chillers. This paper provides an explicit equation for the optimum temperature of vapor generation, in terms of only the external temperatures of the chiller. The additional data required are the four performance parameters of the chiller and essentially a modified stagnation temperature from the detailed model of the thermal collector operation. This paper presents and discusses the results for small capacity machines for air conditioning of homes and small buildings. The discussion highlights the influence of the relevant parameters. (author)

  13. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  14. Establish feasibility for providing passive cooling with solar updraft and evaporate downdraft chimneys

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-01-01

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some applications.

  15. Methodology to determine cost and performance goals for active solar cooling systems

    NASA Astrophysics Data System (ADS)

    Warren, M. L.; Wahlig, M.

    1981-11-01

    Systems analysis is used to calculate the 20 yr. present value of energy savings of solar cooling systems located in Texas, Arizona, Florida, and Washington, DC, and methods of solar system development to meet the cost goals of economic operation are outlined. Solar cooling systems are projected to begin commercial entry in 1986 and reach 20% of the total cooling market by the year 2000, producing 0.14 quads of displaced energy. A numerical simulation was carried out for both residential and commercial solar cooling units with consideration for system cost goals, cost goals per unit collector area, and the cost goals per ton of cooling. System size was targeted as a 3 ton residential chiller and a 25 ton commercial absorption cooling unit. The costs for volume production are provided, along with trends for an incrementally decreasing need for tax incentives, ending in about 1994

  16. Solar energy to heat and cool a new NASA Langley office building

    NASA Technical Reports Server (NTRS)

    Maag, W. L.

    1974-01-01

    A solar heating and cooling system will be installed at a new NASA office building. The objective of this project is to establish a full-scale working test-bed facility to investigate solar energy for heating and cooling buildings. The energy collected will provide between 80 and 100 percent of the heating and cooling requirements during the cool months and between one-half and two-thirds of the cooling requirements in the summer. Thermal energy storage will be provided to bridge the gap between cloudy and clear days.

  17. Available solar exergy in an absorption cooling process

    SciTech Connect

    Millan, M.I.; Martin, E.; Hernandez, F.

    1996-06-01

    Using the global solar radiation on a flat plate converter of selective surface, the process temperature, the ambient temperature and the characteristics of the collector as initial data; the maximum available exergy for feeding a lithium bromide absorption cooling machine and its daily distribution in Madrid is determined. The conversion of solar radiation into exergy is calculated through the Mueser endoreversible engine. The model, which takes into account the relative Sun-Earth movements, the presence of the atmosphere, the transitory regime, the losses to the surroundings and the losses caused by the heat capacities effect, allows a maximum hourly exergy efficiency of the available heat between 11 and 14.6% and a daily exergy efficiency in the order of 3% to be obtained. The maximum available daily exergy varies from 800 kJ/(m{sup 2} day) for a very hot clear day to 950 kJ/(m{sup 2} day) for a warm clear day. 11 refs., 2 figs., 4 tabs.

  18. Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey. Final report

    SciTech Connect

    1981-03-01

    Solar heating and cooling of a 40,000 square foot manufacturing building, sales offices and the solar computer control center/display room are described. Information on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature and as-built drawings are provided also. The solar system is composed of 6000 square feet of Sunworks double glazed flat plate collectors, external above ground storage subsystem, controls, ARKLA absorption chiller, heat recovery and a cooling tower.

  19. Guidelines for selecting a solar heating, cooling or hot water design

    SciTech Connect

    Kelly, C.J. Jr.

    1981-12-01

    Guidelines are presented for the professional who may have to choose between competing solar heating and cooling designs for buildings. The experience of the National Solar Data Network in monitoring over 100 solar installations are drawn upon. Three basic principles and a design selection checklist are developed which will aid in choosing the most cost effective design.

  20. Solar heating and cooling demonstration project at Radian Corporation, Austin, Texas

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar heating and cooling system located at the Radian Corporation, Austin, Texas, is discussed. A technical description of the solar system is presented. The costs of the major components and the cost of installing the system are described. Flow diagrams and photographs of the solar system are provided.

  1. Analysis of the Solar Radiation Impact on Cooling Performance of the Absorption Chiller

    NASA Astrophysics Data System (ADS)

    Fedorčák, Pavol; Košičanová, Danica; Nagy, Richard; Mlynár, Peter

    2014-11-01

    Absorption cooling at low power is a new technology which has not yet been applied to current conditioning elements. This paper analyzes the various elements of solar absorption cooling. Individual states were simulated in which working conditions were set for the capability of solar absorption cooling to balance heat loads in the room. The research is based on an experimental device (absorption units with a performance of 10kW) developed at the STU in Bratislava (currently inputs and outputs of cold sources are being measured). Outputs in this paper are processed so that they connect the entire scheme of the solar absorption cooling system (i.e. the relationship between the solar systems hot and cold storage and the absorption unit). To determine the size of the storage required, calculated cooling for summer months is considered by the ramp rate of the absorption unit and required flow rate of the collectors.

  2. The development of a solar-powered residential heating and cooling system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Efforts to demonstrate the engineering feasibility of utilizing solar power for residential heating and cooling are described. These efforts were concentrated on the analysis, design, and test of a full-scale demonstration system which is currently under construction at the National Aeronautics and Space Administration, Marshall Space Flight Center, Huntsville, Alabama. The basic solar heating and cooling system under development utilizes a flat plate solar energy collector, a large water tank for thermal energy storage, heat exchangers for space heating and water heating, and an absorption cycle air conditioner for space cooling.

  3. The NASA-Lewis/ERDA solar heating and cooling technology program. [project planning/energy policy

    NASA Technical Reports Server (NTRS)

    Couch, J. P.; Bloomfield, H. S.

    1975-01-01

    Plans by NASA to carry out a major role in a solar heating and cooling program are presented. This role would be to create and test the enabling technology for future solar heating, cooling, and combined heating/cooling systems. The major objectives of the project are to achieve reduction in solar energy system costs, while maintaining adequate performance, reliability, life, and maintenance characteristics. The project approach is discussed, and will be accomplished principally by contract with industry to develop advanced components and subsystems. Advanced hardware will be tested to establish 'technology readiness' both under controlled laboratory conditions and under real sun conditions.

  4. 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.

  5. Survey and evaluation of available thermal insulation materials for use on solar heating and cooling systems

    SciTech Connect

    Not Available

    1980-03-01

    This is the final report of a survey and evaluation of insulation materials for use with components of solar heating and cooling systems. The survey was performed by mailing questionnaires to manufacturers of insulation materials and by conducting an extensive literature search to obtain data on relevant properties of various types of insulation materials. The study evaluated insulation materials for active and passive solar heating and cooling systems and for multifunction applications. Primary and secondary considerations for selecting insulation materials for various components of solar heating and cooling systems are presented.

  6. Site dependent factors affecting the economic feasibility of solar powered absorption cooling

    NASA Technical Reports Server (NTRS)

    Bartlett, J. C.

    1978-01-01

    A procedure was developed to evaluate the cost effectiveness of combining an absorption cycle chiller with a solar energy system. A basic assumption of the procedure is that a solar energy system exists for meeting the heating load of the building, and that the building must be cooled. The decision to be made is to either cool the building with a conventional vapor compression cycle chiller or to use the existing solar energy system to provide a heat input to the absorption chiller. Two methods of meeting the cooling load not supplied by solar energy were considered. In the first method, heat is supplied to the absorption chiller by a boiler using fossil fuel. In the second method, the load not met by solar energy is net by a conventional vapor compression chiller. In addition, the procedure can consider waste heat as another form of auxiliary energy. Commercial applications of solar cooling with an absorption chiller were found to be more cost effective than the residential applications. In general, it was found that the larger the chiller, the more economically feasible it would be. Also, it was found that a conventional vapor compression chiller is a viable alternative for the auxiliary cooling source, especially for the larger chillers. The results of the analysis gives a relative rating of the sites considered as to their economic feasibility of solar cooling.

  7. Initial operation of a solar heating and cooling system in a full-scale solar building test facility

    NASA Technical Reports Server (NTRS)

    Knoll, R. H.; Miao, D.; Hamlet, I. L.; Jensen, R. N.

    1976-01-01

    The Solar Building Test Facility (SBTF) located at Hampton, Virginia became operational in early summer of 1976. This facility is a joint effort by NASA-Lewis and NASA-Langley to advance the technology for heating and cooling of office buildings with solar energy. Its purposes are to (1) test system components which include high-performing collectors, (2) test performance of complete solar heating and cooling system, (3) investigate component interactions and (4) investigate durability, maintenance and reliability of components. The SBTF consists of a 50,000 square foot office building modified to accept solar heated water for operation of an absorption air conditioner and for the baseboard heating system. A 12,666 square foot solar collector field with a 30,000 gallon storage tank provides the solar heated water. A description of the system and the collectors selected is given here, along with the objectives, test approach, expected system performance and some preliminary results.

  8. Initial operation of a solar heating and cooling system in a full-scale solar building test facility

    NASA Technical Reports Server (NTRS)

    Knoll, R. H.; Miao, D.; Hamlet, I. L.; Jensen, R. N.

    1976-01-01

    The Solar Building Test Facility (SBTF) was constructed to advance the technology for heating and cooling of office buildings with solar energy. Its purposes are to (1) test system components which include high-performing collectors, (2) test the performance of a complete solar heating and cooling system, (3) investigate component interactions, and (4) investigate durability, maintenance and reliability of components. The SBTF consists of a 50,000 square foot office building modified to accept solar heated water for operation of an absorption air conditioner and for the baseboard heating system. A 12,666 square foot solar collector field with a 30,000 gallon storage tank provides the solar heated water. A description of the system and the collectors selected is printed along with the objectives, test approach, expected system performance, and some preliminary results.

  9. Development and testing of heat transport fluids for use in active solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Parker, J. C.

    1981-01-01

    Work on heat transport fluids for use with active solar heating and cooling systems is described. Program objectives and how they were accomplished including problems encountered during testing are discussed.

  10. Characterization of selected application of biomass energy technologies and a solar district heating and cooling system

    SciTech Connect

    D'Alessio, Dr., Gregory J.; Blaunstein, Robert P.

    1980-09-01

    The following systems are discussed: energy self-sufficient farms, wood gasification, energy from high-yield silviculture farms, and solar district heating and cooling. System descriptions and environmental data are included for each one. (MHR)

  11. Energy-efficient regenerative liquid desiccant drying process

    DOEpatents

    Ko, Suk M.; Grodzka, Philomena G.; McCormick, Paul O.

    1980-01-01

    This invention relates to the use of desiccants in conjunction with an open oop drying cycle and a closed loop drying cycle to reclaim the energy expended in vaporizing moisture in harvested crops. In the closed loop cycle, the drying air is brought into contact with a desiccant after it exits the crop drying bin. Water vapor in the moist air is absorbed by the desiccant, thus reducing the relative humidity of the air. The air is then heated by the used desiccant and returned to the crop bin. During the open loop drying cycle the used desiccant is heated (either fossil or solar energy heat sources may be used) and regenerated at high temperature, driving water vapor from the desiccant. This water vapor is condensed and used to preheat the dilute (wet) desiccant before heat is added from the external source (fossil or solar). The latent heat of vaporization of the moisture removed from the desiccant is reclaimed in this manner. The sensible heat of the regenerated desiccant is utilized in the open loop drying cycle. Also, closed cycle operation implies that no net energy is expended in heating drying air.

  12. Passive solar space heating and cooling. (Latest citations from the NTIS Bibliographic database). NewSearch

    SciTech Connect

    Not Available

    1994-10-01

    The bibliography contains citations concerning the passive use of solar energy for space heating and cooling in buildings, houses, and homes. Citations discuss the design, performance, models, and economic analysis of heating and cooling systems. Topics include solar architecture, energy consumption analysis, energy conservation, and heat recovery. Also included are thermal comfort, quality of life, and housing for the elderly. (Contains a minimum of 209 citations and includes a subject term index and title list.)

  13. Influence of solar variability on the infrared radiative cooling of the thermosphere from 2002 to 2014.

    PubMed

    Mlynczak, Martin G; Hunt, Linda A; Mertens, Christopher J; Thomas Marshall, B; Russell, James M; Woods, Thomas; Earl Thompson, R; Gordley, Larry L

    2014-04-16

    Infrared radiative cooling of the thermosphere by carbon dioxide (CO2, 15 µm) and by nitric oxide (NO, 5.3 µm) has been observed for 12 years by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on the Thermosphere-Ionosphere-Mesosphere Energetics and Dynamics satellite. For the first time we present a record of the two most important thermospheric infrared cooling agents over a complete solar cycle. SABER has documented dramatic variability in the radiative cooling on time scales ranging from days to the 11 year solar cycle. Deep minima in global mean vertical profiles of radiative cooling are observed in 2008-2009. Current solar maximum conditions, evidenced in the rates of radiative cooling, are substantially weaker than prior maximum conditions in 2002-2003. The observed changes in thermospheric cooling correlate well with changes in solar ultraviolet irradiance and geomagnetic activity during the prior maximum conditions. NO and CO2 combine to emit 7 × 10(18) more Joules annually at solar maximum than at solar minimum.

  14. Solar Heating and Cooling of Buildings (Phase O). Volume 1: Executive Summary.

    ERIC Educational Resources Information Center

    TRW Systems Group, Redondo Beach, CA.

    The purpose of this study was to establish the technical and economic feasibility of using solar energy for the heating and cooling of buildings. Five selected building types in 14 selected cities were used to determine loads for space heating, space cooling and dehumidification, and domestic service hot water heating. Relying on existing and…

  15. Kelvin-Helmholtz instability in solar cool surges

    NASA Astrophysics Data System (ADS)

    Zhelyazkov, I.; Zaqarashvili, T. V.; Chandra, R.; Srivastava, A. K.; Mishonov, T.

    2015-12-01

    We study the conditions for onset of Kelvin-Helmholtz (KH) instability in a cool solar surge observed in NOAA AR 8227 on 1998 May 30. The jet with speeds in the range of 45-50 km s-1, width of 7 Mm, and electron number density of 3.83 ×1010 cm-3 is assumed to be confined in a twisted magnetic flux tube embedded in a magnetic field of 7 G. The temperature of the plasma flow is of the order of 105 K while that of its environment is taken to be 2 ×106 K. The electron number density of surrounding magnetized plasma has a typical value for the TR/lower corona region of 2 ×109 cm-3. Under these conditions, the Alfvén speed inside the jet is equal to 78.3 km s-1. We model the surge as a moving magnetic flux tube for two magnetic field configurations: (i) a twisted tube surrounded by plasma with homogeneous background magnetic field, and (ii) a twisted tube which environment is plasma with also twisted magnetic field. The magnetic field twist in given region is characterized by the ratio of azimuthal to the axial magnetic field components evaluated at the flux tube radius. The numerical studies of appropriate dispersion relations of MHD modes supported by the plasma flow in both magnetic field configurations show that the Kelvin-Helmholtz instability can only occur for MHD waves propagating in axial direction, but with high negative azimuthal mode numbers, and the instability occurs at sub-Alfvénic critical flow velocities in the range of 24-60 km s-1.

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

    ERIC Educational Resources Information Center

    AAI Corp., Baltimore, MD.

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

  17. Tests of a reduced-scale experimental model of a building solar heating-cooling system

    NASA Technical Reports Server (NTRS)

    Namkoong, D.

    1976-01-01

    An experimental solar heating and cooling system model has been built and operated, combining elements that are programmable (e.g., heating and cooling load of a building and collected solar energy) with experimental equipment. The experimental system model was based on the loads and components used in the Solar Building Test Facility (SBTF), which includes a 1394 sq m solar collector field at NASA Langley. These tests covered 5 continuous days under summer conditions. For the system model up to 55 percent of the simulated collected solar energy was used for the building load. This amount of solar energy supplied 35 percent of the building cooling load. Heat loss was significant. If tank heat loss were eliminated, which would make it similar to the actual SBTF, 75 percent of the collected solar energy would be used. This amount would supply approximately 50 percent of the building cooling load. A higher fraction of solar energy is possible with a more performance-optimized system.

  18. Solar Heating and Cooling Experiment for a School in Atlanta. Performance Report.

    ERIC Educational Resources Information Center

    Westinghouse Electric Corp., Falls Church, VA.

    This report documents the performance and conclusions of a 13-month period of monitoring the performance of the experimental solar heating and cooling system installed in the George A. Towns Elementary School, Atlanta, Georgia. The objectives of the project were to (1) make a significant contribution to solar design, technology, and acceptability;…

  19. Active Desiccant-Based Preconditioning Market Analysis and Product Development

    SciTech Connect

    Fischer, J.

    2001-01-11

    The Phase 1 report (ORNL/Sub/94-SVO44/1), completed earlier in this program, involved a comprehensive field survey and market analysis comparing various specialized outdoor air handling units. This initial investigation included conventional cooling and reheat, conventional cooling with sensible recovery, total energy recovery systems (passive desiccant technology) and various active desiccant systems. The report concluded that several markets do promise a significant sales opportunity for a Climate Changer-based active desiccant system offering. (Climate Changer is a registered trademark of Trane Company.) This initial market analysis defined the wants and needs of the end customers (design engineers and building owners), which, along with subsequent information included in this report, have been used to guide the determination of the most promising active desiccant system configurations. This Phase 2 report begins with a summary of a more thorough investigation of those specific markets identified as most promising for active desiccant systems. Table 1 estimates the annual sales potential for a cost-effective product line of active desiccant systems, such as that built from Climate Changer modules. The Product Development Strategy section describes the active desiccant system configurations chosen to best fit the needs of the marketplace while minimizing system options. Key design objectives based on market research are listed in this report for these active desiccant systems. Corresponding performance goals for the dehumidification wheel required to meet the overall system design objectives are also defined. The Performance Modeling section describes the strategy used by SEMCO to design the dehumidification wheels integrated into the prototype systems currently being tested as part of the U.S. Department of Energy's Advanced Desiccant Technology Program. Actual performance data from wheel testing was used to revise the system performance and energy analysis

  20. 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.

  1. Design and operation of a solar heating and cooling system for a residential size building

    NASA Technical Reports Server (NTRS)

    Littles, J. W.; Humphries, W. R.; Cody, J. C.

    1978-01-01

    The first year of operation of solar house is discussed. Selected design information, together with a brief system description is included. The house was equipped with an integrated solar heating and cooling system which uses fully automated state-of-the art. Evaluation of the data indicate that the solar house heating and cooling system is capable of supplying nearly 100 percent of the thermal energy required for heating and approximately 50 percent of the thermal energy required to operate the absorption cycle air conditioner.

  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. Integrated Modeling of Building Energy Requirements IncorporatingSolar Assisted Cooling

    SciTech Connect

    Firestone, Ryan; Marnay, Chris; Wang, Juan

    2005-08-10

    This paper expands on prior Berkeley Lab work on integrated simulation of building energy systems by the addition of active solar thermal collecting devices, technology options not previously considered (Siddiqui et al 2005). Collectors can be used as an alternative or additional source of hot water to heat recovery from reciprocating engines or microturbines. An example study is presented that evaluates the operation of solar assisted cooling at a large mail sorting facility in southern California with negligible heat loads and year-round cooling loads. Under current conditions solar thermal energy collection proves an unattractive option, but is a viable carbon emission control strategy.

  4. Cooling a solar telescope enclosure: plate coil thermal analysis

    NASA Astrophysics Data System (ADS)

    Gorman, Michael; Galapon, Chriselle; Montijo, Guillermo; Phelps, LeEllen; Murga, Gaizka

    2016-08-01

    The climate of Haleakalā requires the observatories to actively adapt to changing conditions in order to produce the best possible images. Observatories need to be maintained at a temperature closely matching ambient or the images become blurred and unusable. The Daniel K. Inouye Solar Telescope is a unique telescope as it will be active during the day as opposed to the other night-time stellar observatories. This means that it will not only need to constantly match the ever-changing temperature during the day, but also during the night so as not to sub-cool and affect the view field of other telescopes while they are in use. To accomplish this task, plate coil heat exchanger panels will be installed on the DKIST enclosure that are designed to keep the temperature at ambient temperature +0°C/-4°C. To verify the feasibility of this and to validate the design models, a test rig has been installed at the summit of Haleakalā. The project's purpose is to confirm that the plate coil panels are capable of maintaining this temperature throughout all seasons and involved collecting data sets of various variables including pressures, temperatures, coolant flows, solar radiations and wind velocities during typical operating hours. Using MATLAB, a script was written to observe the plate coil's thermal performance. The plate coil did not perform as expected, achieving a surface temperature that was generally 2ºC above ambient temperature. This isn't to say that the plate coil does not work, but the small chiller used for the experiment was undersized resulting in coolant pumped through the plate coil that was not supplied at a low enough temperature. Calculated heat depositions were about 23% lower than that used as the basis of the design for the hillers to be used on the full system, a reasonable agreement given the fact that many simplifying assumptions were used in the models. These were not carried over into the testing. The test rig performance showing a 23% margin

  5. Comparison of solar panel cooling system by using dc brushless fan and dc water

    NASA Astrophysics Data System (ADS)

    Irwan, Y. M.; Leow, W. Z.; Irwanto, M.; M, Fareq; Hassan, S. I. S.; Safwati, I.; Amelia, A. R.

    2015-06-01

    The purpose of this article is to discuss comparison of solar panel cooling system by using DC brushless fan and DC water pump. Solar photovoltaic (PV) power generation is an interesting technique to reduce non-renewable energy consumption and as a renewable energy. The temperature of PV modules increases when it absorbs solar radiation, causing a decrease in efficiency. A solar cooling system is design, construct and experimentally researched within this work. To make an effort to cool the PV module, Direct Current (DC) brushless fan and DC water pump with inlet/outlet manifold are designed for constant air movement and water flow circulation at the back side and front side of PV module representatively. Temperature sensors were installed on the PV module to detect temperature of PV. PIC microcontroller was used to control the DC brushless fan and water pump for switch ON or OFF depend on the temperature of PV module automatically. The performance with and without cooling system are shown in this experiment. The PV module with DC water pump cooling system increase 3.52%, 36.27%, 38.98%in term of output voltage, output current, output power respectively. It decrease 6.36 °C compare than to PV module without DC water pump cooling system. While DC brushless fan cooling system increase 3.47%, 29.55%, 32.23%in term of output voltage, output current, and output power respectively. It decrease 6.1 °C compare than to PV module without DC brushless fan cooling system. The efficiency of PV module with cooling system was increasing compared to PV module without cooling system; this is because the ambient temperature dropped significantly. The higher efficiency of PV cell, the payback period of the system can be shorted and the lifespan of PV module can also be longer.

  6. Degradation of desiccants upon contamination: An experimental study

    SciTech Connect

    Pesaran, A A

    1990-11-01

    Experiments were conducted to quantify the effects of thermal cycling and exposure to contamination on solid desiccant materials that may be used in desiccant cooling systems. A test apparatus was used to thermally cycle several desiccant samples and expose them to ambient or contaminated humid air. The source of contamination was cigarette smoke. Six different solid desiccants were tested: two types of silica gel, activated alumina, activated carbon, molecular sieves, and lithium chloride. The exposed desiccant samples were removed after 0.5, 1, 2, 4, or 11 months of exposure and their moisture capacities were measured. Other tests were conducted to characterize pollutants deposited on the exposed samples or to evaluate impact of exposure on internal structure of the samples. Compared to fresh samples, the capacity loss due to thermal cycling with ambient air was generally 10% to 30%. The capacity loss due to only cigarette smoke was generally between 20% to 50%. 7 refs., 8 figs., 3 tabs.

  7. National commercial solar heating and cooling demonstration: purposes, program activities, and implications for future programs

    SciTech Connect

    Koontz, R.; Genest, M.; Bryant, B.

    1980-05-01

    The Solar Heating and Cooling Demonstration Act of 1974 created a set of activities to demonstrate the potential use of solar heating within a three-year period and of combined solar heating and cooling within a five-year period. This study assesses the Commercial Demonstration Program portion of the activity in terms of its stated goals and objectives. The primary data base was DOE contractor reports on commercial demonstration projects. It was concluded that the program did not provide data to support a positive decision for the immediate construction or purchase of commercial solar systems. However, the program may have contributed to other goals in the subsequent legislation; i.e., research and development information, stimulation of the solar industry, and more informed policy decisions.

  8. Solar cooling - comparative study between thermal and electrical use in industrial buildings

    NASA Astrophysics Data System (ADS)

    Badea, N.; Badea, G. V.; Epureanu, A.; Frumuşanu, G.

    2016-08-01

    The increase in the share of renewable energy sources together with the emphasis on the need for energy security bring to a spotlight the field of trigeneration autonomous microsystems, as a solution to cover the energy consumptions, not only for isolated industrial buildings, but also for industrial buildings located in urban areas. The use of solar energy for cooling has been taken into account to offer a cooling comfort in the building. Cooling and air- conditioned production are current applications promoting the use of solar energy technologies. Solar cooling systems can be classified, depending on the used energy, in electrical systems using mechanical compression chillers and systems using thermal compression by absorption or adsorption. This comparative study presents the main strengths and weaknesses of solar cooling obtained: i) through the transformation of heat resulted from thermal solar panels combined with adsorption chillers, and ii) through the multiple conversion of electricity - photovoltaic panels - battery - inverter - combined with mechanical compression chillers. Both solutions are analyzed from the standpoints of energy efficiency, dynamic performances (demand response), and costs sizes. At the end of the paper, experimental results obtained in the climatic condition of Galafi city, Romania, are presented.

  9. Enhancing photovoltaic efficiency through radiative cooling of solar cells below ambient temperature

    NASA Astrophysics Data System (ADS)

    Safi, Taqiyyah; Munday, Jeremy

    Sunlight heats up solar cells and the resulting elevated solar cell temperature adversely effects the photovoltaic efficiency and the reliability of the cell. Currently, a variety of active and passive cooling strategies are used to lower the operating temperature of the solar cell. Passive radiative cooling requires no energy input, and is ideal for solar cells; however, previously demonstrated devices still operate above the ambient, leading to a lower efficiency as compared to the ideal Shockley-Queisser limit, which is defined for a cell in contact with an ideal heat sink at ambient temperature (300 K). In this talk, we will describe the use of radiative cooling techniques to lower the cell temperature below the ambient temperature. We show that by combining specifically designed radiative cooling structures with solar cells, efficiencies higher than the limiting efficiency achievable at 300 K can be obtained for solar cells in both terrestrial and extraterrestrial environments. We show that these structures yield an efficiency 0.87% higher than a typical PV module at operating temperatures in a terrestrial application. We also demonstrate an efficiency advantage of 0.4-2.6% for cells in an extraterrestrial environment in near-earth orbit.

  10. A multifunction wall system for application with solar heating and ground cooling

    NASA Astrophysics Data System (ADS)

    Riley, J. F.; Schubert, R. P.

    1985-01-01

    The research presented in this report is an exploration of one alternative energy building system concept which is attempting to produce performance characteristics in a way closely approaching those of conventional fossil fuel heating and cooling systems. This alternative energy building system is a multifunction wall system for application with solar-heating and ground-cooling. The concept of the system is to expand the use of structure and enclosure elements of a building to function additionally as: (1) the ductwork for the solar-heated or earth-cooled air; (2) the heat transfer membrane between the heated or cooled air and the living environment of the building; (3) the heat storage medium (in winter); and (4) the temperature leveling and control medium. All these functions are integrated into a single wall construction using a new concrete block, surface-bonding cement, and the exterior insulation system. This report presents the series of experiments conducted on the Multifunction Wall System.

  11. A Novel Approach to Thermal Design of Solar Modules: Selective-Spectral and Radiative Cooling

    SciTech Connect

    Sun, Xingshu; Dubey, Rajiv; Chattopadhyay, Shashwata; Khan, Mohammad Ryyan; Chavali, Raghu Vamsi; Silverman, Timothy J.; Kottantharayil, Anil; Vasi, Juzer; Alam, Muhammad Ashraful

    2016-11-21

    For commercial solar modules, up to 80% of the incoming sunlight may be dissipated as heat, potentially raising the temperature 20-30 degrees C higher than the ambient. In the long run, extreme self-heating may erode efficiency and shorten lifetime, thereby, dramatically reducing the total energy output by almost ~10% Therefore, it is critically important to develop effective and practical cooling methods to combat PV self-heating. In this paper, we explore two fundamental sources of PV self-heating, namely, sub-bandgap absorption and imperfect thermal radiation. The analysis suggests that we redesign the optical and thermal properties of the solar module to eliminate the parasitic absorption (selective-spectral cooling) and enhance the thermal emission to the cold cosmos (radiative cooling). The proposed technique should cool the module by ~10 degrees C, to be reflected in significant long-term energy gain (~ 3% to 8% over 25 years) for PV systems under different climatic conditions.

  12. Solar-powered saline sorbent-solution heat pump/storage system

    NASA Astrophysics Data System (ADS)

    Robison, H.; Houston, S.

    Coastal Energy Laboratory Chemical Heat Pump (CEL-CHEAP) is a redesigned open-cycle liquid desiccant air conditioner. Heat is discharged to shallow-well water by dehumidification-humidification for cooling and extracted by humidification-dehumidification for heating. Direct solar radiation concentrates the desiccant. For continuous operation, a small uninsulated tank stores concentrated solution. This chemical heat pump needs no mechanical compressor, condenser, vacuum system, or pressure system. The collector-regenerators are inexpensive. The refrigerant is water and the desiccant is calcium chloride. First cost and operating expenses are very low.

  13. Hardware problems encountered in solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Cash, M.

    1978-01-01

    Numerous problems in the design, production, installation, and operation of solar energy systems are discussed. Described are hardware problems, which range from simple to obscure and complex, and their resolution.

  14. Solar-heating and cooling system design package

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Package of information includes design data, performance specifications, drawings, hazard analysis, and spare parts list for commercially produced system installed in single-family dwelling in Akron, Ohio. System uses air flat-plate collectors, 12000 kg rock storage and backup heat pump. Solar portion requires 0.7 kW, and provides 35% of average total heating load including hot water. Information aids persons considering installing solar home-heating systems.

  15. Impact of Hybrid Wet/Dry Cooling on Concentrating Solar Power Plant Performance

    SciTech Connect

    Wagner, M. J.; Kutscher, C.

    2010-01-01

    This paper examines the sensitivity of Rankine cycle plant performance to dry cooling and hybrid (parallel) wet/dry cooling combinations with the traditional wet-cooled model as a baseline. Plants with a lower temperature thermal resource are more sensitive to fluctuations in cooling conditions, and so the lower temperature parabolic trough plant is analyzed to assess the maximum impact of alternative cooling configurations. While low water-use heat rejection designs are applicable to any technology that utilizes a Rankine steam cycle for power generation, they are of special interest to concentrating solar power (CSP) technologies that are located in arid regions with limited water availability. System performance is evaluated using hourly simulations over the course of a year at Daggett, CA. The scope of the analysis in this paper is limited to the power block and the heat rejection system, excluding the solar field and thermal storage. As such, water used in mirror washing, maintenance, etc., is not included. Thermal energy produced by the solar field is modeled using NREL's Solar Advisor Model (SAM).

  16. Solar heating and cooling system installed at RKL Controls Company, Lumberton, New Jersey

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The final results of the design and operation of a computer controlled solar heated and cooled 40,000 square foot manufacturing building, sales office, and computer control center/display room are summarized. The system description, test data, major problems and resolutions, performance, operation and maintenance manual, equipment manufacturers' literature, and as-built drawings are presented. The solar system is composed of 6,000 square feet of flat plate collectors, external above ground storage subsystem, controls, absorption chiller, heat recovery, and a cooling tower.

  17. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody

    PubMed Central

    Zhu, Linxiao; Raman, Aaswath P.; Fan, Shanhui

    2015-01-01

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities. PMID:26392542

  18. Solar heating, cooling, and hot water systems installed at Richland, Washington

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The project described is part of the U. S. Department of Energy's solar demonstration program, and became operational in April 1978. The solar system uses 6,000 square feet of flat-plate liquid collectors in a closed loop to deliver solar energy through a liquid-liquid heat exchanger to the building heat-pump duct work or 9,000-gallon thermal energy storage tank. A 25-ton Arkla solar-driven absorption chiller provides the cooling, in conjunction with a 2,000 gallon chilled water storage tank and reflective ponds on three sides of the building surplus heat. A near-by building is essentially identical except for having conventional heat-pump heating and cooling, and can serve as an experimental control. An on-going public relations program was provided from the beginning of the program, and resulted in numerous visitors and tour groups.

  19. Direct contact liquid-liquid heat exchanger for solar heated and cooled buildings

    NASA Astrophysics Data System (ADS)

    Karaki, S.; Brothers, P.

    1980-06-01

    The technical and economic feasibility of using a direct contract liquid-liquid heat exchanger (DCLLHE) storage unit in a solar heating and cooling system is established. Experimental performance data were obtained from the CSU Solar House I using a DCLLHE for both heating and cooling functions. A simulation model for the system was developed. The model was validated using the experimental data and applied in five different climatic regions of the country for a complete year. The life-cycle cost of the system was estimated for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger. It is concluded that while there is a performance advantage with a DCLLHE system over a conventional solar system, the advantage is not sufficiently large to overcome slightly higher capital and operating costs for the DCLLHE system.

  20. Radiative cooling of solar absorbers using a visibly transparent photonic crystal thermal blackbody.

    PubMed

    Zhu, Linxiao; Raman, Aaswath P; Fan, Shanhui

    2015-10-06

    A solar absorber, under the sun, is heated up by sunlight. In many applications, including solar cells and outdoor structures, the absorption of sunlight is intrinsic for either operational or aesthetic considerations, but the resulting heating is undesirable. Because a solar absorber by necessity faces the sky, it also naturally has radiative access to the coldness of the universe. Therefore, in these applications it would be very attractive to directly use the sky as a heat sink while preserving solar absorption properties. Here we experimentally demonstrate a visibly transparent thermal blackbody, based on a silica photonic crystal. When placed on a silicon absorber under sunlight, such a blackbody preserves or even slightly enhances sunlight absorption, but reduces the temperature of the underlying silicon absorber by as much as 13 °C due to radiative cooling. Our work shows that the concept of radiative cooling can be used in combination with the utilization of sunlight, enabling new technological capabilities.

  1. Optimum dry-cooling sub-systems for a solar air conditioner

    NASA Technical Reports Server (NTRS)

    Chen, J. L. S.; Namkoong, D.

    1978-01-01

    Dry-cooling sub-systems for residential solar powered Rankine compression air conditioners were economically optimized and compared with the cost of a wet cooling tower. Results in terms of yearly incremental busbar cost due to the use of dry-cooling were presented for Philadelphia and Miami. With input data corresponding to local weather, energy rate and capital costs, condenser surface designs and performance, the computerized optimization program yields design specifications of the sub-system which has the lowest annual incremental cost.

  2. Solar heating and cooling system for an office building at Reedy Creek Utilities

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The solar energy system installed in a two story office building at a utilities company, which provides utility service to Walt Disney World, is described. The solar energy system application is 100 percent heating, 80 percent cooling, and 100 percent hot water. The storage medium is water with a capacity of 10,000 gallons hot and 10,000 gallons chilled water. Performance to date has equaled or exceeded design criteria.

  3. Direct contact liquid-liquid heat exchanger for solar-heated and cooled buildings

    NASA Astrophysics Data System (ADS)

    Karaki, S.; Brothers, P.

    1980-06-01

    The procedure used was to obtain experimental performance data from a solar system using a DCLLHE for both heating and cooling functions, develop a simulation model for the system, validate the model using the data, apply the model in five different climatic regions of the country for a complete year, and estimate the life-cycle cost of the system for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger.

  4. Considerations for performance evaluation of solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Littles, J. W.; Cody, J. C.

    1975-01-01

    One of the many factors which must be considered in performance evaluation of solar energy systems is the relative merit of a given solar energy system when compared to a standard conventional system. Although initial and operational costs will be dominant factors in the comparison of the two types of systems and will be given prime consideration in system selection, sufficient data are not yet available for a definitive treatment of these variables. It is possible, however, to formulate relationships between the nonsolar energy requirements of the solar energy systems and the energy requirements of a conventional system in terms of the primary performance parameters of the systems. Derivations of such relationships, some parametric data for selected ranges of the performance parameters, and data with respect to limiting conditions are presented.

  5. Solar heating and cooling system design and development

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Application surveys and performance studies were conducted to determine a solar heating and hot water configuration that could be used in a variety of applications, and to identify subsystem modules that could be utilized in a building block fashion to adapt hardware items to single and multi-family residential and commercial systems. Topics discussed include: subsystem development for the solar collectors, controls, other components, energy management module, and the heating system configuration test. Operational tests conducted at an Illinois farmhouse, and a YWCA in Spokane, Washington are discussed.

  6. How to solve materials and design problems in solar heating and cooling. Energy technology review No. 77

    SciTech Connect

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

    1982-01-01

    A broad range of difficulties encountered in active and passive solar space heating systems and active solar space cooling systems is covered. The problems include design errors, installation mistakes, inadequate durability of materials, unacceptable reliability of components, and wide variations in performance and operation of different solar systems. Feedback from designers and manufacturers involved in the solar market is summarized. The designers' experiences with and criticisms of solar components are presented, followed by the manufacturers' replies to the various problems encountered. Information is presented on the performance and operation of solar heating and cooling systems so as to enable future designs to maximize performance and eliminate costly errors. (LEW)

  7. Review of state-of-the-art of solar collector corrosion processes. Task 1 of solar collector studies for solar heating and cooling applications. Final technical progress report

    SciTech Connect

    Clifford, J E; Diegle, R B

    1980-04-11

    The state-of-the-art of solar collector corrosion processes is reviewed, and Task 1 of a current research program on use of aqueous heat transfer fluids for solar heating and cooling is summarized. The review of available published literature has indicated that lack of quantitative information exists relative to collector corrosion at the present time, particularly for the higher temperature applications of solar heating and cooling compared to domestic water heating. Solar collector systems are reviewed from the corrosion/service life viewpoint, with emphasis on various applications, collector design, heat transfer fluids, and freeze protection methods. Available information (mostly qualitative) on collector corrosion technology is reviewed to indicate potential corrosion problem areas and corrosion prevention practices. Sources of limited quantitative data that are reviewed are current solar applications, research programs on collector corrosion, and pertinent experience in related applications of automotive cooling and non-solar heating and cooling. A data bank was developed to catalog corrosion information. Appendix A of this report is a bibliography of the data bank, with abstracts reproduced from presently available literature accessions (about 220). This report is presented as a descriptive summary of information that is contained in the data bank.

  8. Corrosion inhibitors for solar heating and cooling systems

    NASA Technical Reports Server (NTRS)

    Humphries, T. S.

    1978-01-01

    Inhibitors which appeared promising in previous tests and additional inhibitors including several proprietary products were evaluated. Evaluation of the inhibitors was based on corrosion protection afforded an aluminum-mild steel-copper-stainless steel assembly in a hot corrosive water. Of the inhibitors tested two were found to be effective and show promise for protecting multimetallic solar heating systems.

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

    SciTech Connect

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

    1980-07-01

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

  10. Design, fabrication, testing, and delivery of a solar energy collector system for residential heating and cooling

    NASA Technical Reports Server (NTRS)

    Holland, T. H.; Borzoni, J. T.

    1976-01-01

    A low cost flat plate solar energy collector was designed for the heating and cooling of residential buildings. The system meets specified performance requirements, at the desired system operating levels, for a useful life of 15 to 20 years, at minimum cost and uses state-of-the-art materials and technology. The rationale for the design method was based on identifying possible material candidates for various collector components and then selecting the components which best meet the solar collector design requirements. The criteria used to eliminate certain materials were: performance and durability test results, cost analysis, and prior solar collector fabrication experience.

  11. Interim Policy Options for Commercialization of Solar Heating and Cooling Systems.

    ERIC Educational Resources Information Center

    Bezdek, Roger

    This interim report reviews the major incentive policy options available to accelerate market penetration of solar heating and cooling (SHAC) systems. Feasible policy options designed to overcome existing barriers to commercial acceptance and market penetration are identified and evaluated. The report is divided into seven sections, each dealing…

  12. Solar Heating and Cooling for a Controls Manufacturing Plant Lumberton, New Jersey

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Comprehensive report documents computer-controlled system which has separate solar-collector and cooling-tower areas located away from building and is completely computer controlled. System description, test data, major problems and resolution, performance, operation and maintenance, manufacturer's literature and drawing comprise part of 257-page report.

  13. Design data brochure for the Owens-Illinois Sunpak (TM) air-cooled solar collector

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information necessary to evaluate the design and installation of the Owens-Illinois Sunpak TM Air-Cooled Solar Collector is presented. Information includes collector features, fluid flow, thermal performance, installation and system tips. The collector utilizes a highly selective wavelength coating in combination with vacuum insulation, which virtually eliminates conduction and convention losses.

  14. National Program for Solar Heating and Cooling of Buildings. Project Data Summaries. Vol. II: Demonstration Support.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    Brief abstracts of projects funded by the Energy Research and Development Administration (ERDA) and conducted under the National Program for Solar Heating and Cooling of Buildings are presented in three volumes. This, the second volume, identifies the major efforts currently underway in support of the national program. The National Aeronautics and…

  15. Passive-solar-cooling system concepts for small office buildings. Final report

    SciTech Connect

    Whiddon, W.I.; Hart, G.K.

    1983-02-01

    This report summarizes the efforts of a small group of building design professionals and energy analysis experts to develop passive solar cooling concepts including first cost estimates for small office buildings. Two design teams were brought together at each of two workshops held in the fall of 1982. Each team included an architect, mechanical engineer, structural engineer, and energy analysis expert. This report presents the passive cooling system concepts resulting from the workshops. It summarizes the design problems, solutions and first-cost estimates relating to each technology considered, and documents the research needs identified by the participants in attempting to implement the various technologies in an actual building design. Each design problem presented at the workshops was based on the reference (base case) small office building analyzed as part of LBL's Cooling Assessment. Chapter II summarizes the thermal performance, physical specifications and estimated first-costs of the base case design developed for this work. Chapters III - VI describe the passive cooling system concepts developed for each technology: beam daylighting; mass with night ventilation; evaporative cooling; and integrated passive cooling systems. The final Chapters, VII and VIII present the preliminary implications for economics of passive cooling technologies (based on review of the design concepts) and recommendations of workshop participants for future research in passive cooling for commercial buildings. Appendices provide backup information on each chapter as indicated.

  16. Passive-solar directional-radiating cooling system

    DOEpatents

    Hull, John R.; Schertz, William W.

    1986-01-01

    A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.

  17. Passive-solar directional-radiating cooling system

    DOEpatents

    Hull, J.R.; Schertz, W.W.

    1985-06-27

    A radiative cooling system for use with an ice-making system having a radiating surface aimed at the sky for radiating energy at one or more wavelength bands for which the atmosphere is transparent and a cover thermally isolated from the radiating surface and transparent at least to the selected wavelength or wavelengths, the thermal isolation reducing the formation of condensation on the radiating surface and/or cover and permitting the radiation to continue when the radiating surface is below the dewpoint of the atmosphere, and a housing supporting the radiating surface, cover and heat transfer means to an ice storage reservoir.

  18. municipal recreation center is heated and cooled by solar energy

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Major fraction of energy requirements for community building is ksupplied by Sun. The 238 flat plate solar collectors are roof mounted on single story structure enclosing gymnasium, locker area, and health care clinic; heat exchanger transfers collected energy to 6,000 gallon storage tank. Final report chronicles project from inception to completion, documenting performance, costs, operating modes, and data acquisition system. Appendix contains manufacturers' product literature and engineering drawings.

  19. A study of different techniques for cooling solar cells in centralized concentrator photovoltaic power plants

    NASA Astrophysics Data System (ADS)

    Fortea, J.-P.

    Methods of cooling solar cells in concentrator assemblies in centralized power plants are examined with regard to feasibility, performance, and cost factors. The lowered efficiencies in Si, Ge, and GaAlAs-GaAs solar cells at elevated temperatures are noted, and the passive cooling system built into the mechanical architecture of the SOPHOCLE 1000 system is described. The cells were mounted on aluminum dissipators equipped with cooling fins. Second generation systems were investigated to achieve further cost reductions, and a numerical model was devised for the cooling operations. Passive coolers were found to be possible for GaAs concentrator assemblies with intensities of up to 500 suns, producing acceptable efficiencies. Passive cooling is not, however, feasible for Si cells over 100 suns concentration for 4 sq cm cells, and 150 suns for 1 sq cm cells. Evaluations of forced air and phase change active cooling systems demonstrate that the phase change, using for example, water, permits substantial weight and cost savings, depending on the particular application.

  20. Solar heating and cooling system installed at Leavenworth, Kansas. Final report

    SciTech Connect

    Perkins, R. M.

    1980-06-01

    The solar heating and cooling system installed at the headquarters of Citizens Mutual Savings Association in Leavenworth, Kansas, is described in detail. The project is part of the U.S. Department of Energy's solar demonstration program and became operational in March, 1979. The designer was TEC, Inc. Consulting Engineers, Kansas City, Missouri and contractor was Norris Brothers, Inc., Lawrence, Kansas. The solar system is expected to furnish 90 percent of the overall heating load, 70 percent of the cooling load and 100 percent of the domestic hot water load. The building has two floors with a total of 12,000 square feet gross area. The system has 120 flat-plate liquid solar panels with a net area of 2200 square feet. Five, 3-ton Arkla solar assisted absorption units provide the cooling, in conjunction with a 3000 gallon chilled water storage tank. Two, 3000 gallon storage tanks are provided with one designated for summer use, whereas both tanks are utilized during winter.

  1. Summary of NASA Lewis Research Center solar heating and cooling and wind energy programs

    NASA Technical Reports Server (NTRS)

    Vernon, R. W.

    1975-01-01

    Plans for the construction and operation of a solar heating and cooling system in conjunction with a office building being constructed at Langley Research Center, are discussed. Supporting research and technology includes: testing of solar collectors with a solar simulator, outdoor testing of collectors, property measurements of selective and nonselective coatings for solar collectors, and a solar model-systems test loop. The areas of a wind energy program that are being conducted include: design and operation of a 100-kW experimental wind generator, industry-designed and user-operated wind generators in the range of 50 to 3000 kW, and supporting research and technology for large wind energy systems. An overview of these activities is provided.

  2. Modelling the solar irradiance during the Maunder Minimum and the corresponding cooling

    SciTech Connect

    Garduno, R.; Mendoza, B.; Adem, J.

    1996-12-31

    Expressions to compute the solar irradiance as a function of the sun rotation rate, sunspot number and solar cycle length, are deduced. They yield a solar irradiance dimmed by about 0.5% during the Maunder Minimum (1660-1720). This parameter is put in the Adem thermodynamic model as an external forcing to simulate the corresponding climate change. Another forcing used is the preindustrial level of atmospheric CO{sub 2} which reinforces the cooling. The model generates three internal feedbacks: cryosphere, cloudiness and water vapor. The output is a cooling of about 0.5 to 1 C, with respect to present climate, depending on the forcings and feedbacks included. These results agree well with those from other authors and with the few historical records.

  3. Natural/passive solar heating and cooling for poultry sheds

    SciTech Connect

    Abd El-Salam, E.M.

    1980-12-01

    Arid climates, as in Egypt and the Middle-East regions, are characterized by large durinal and seasonal temperature variation coupled with clear skies and ample sunshine duration. Partial stabilization of indoor thermal environment in habitation is of great comfort for human and have large effects on animals or birds productivities. In case of poultry or animal sheds, can have some economical turn over in terms of increased egg or animal productivity and reduction of mortality rates if their indoor thermal environment is favorably controlled. Poultry birds are sensitive to changes of ambient temperatures, humidity and other environmental variables. This investigation describes an unconventional method of maintaining moderate thermal environment within poultry sheds by using the roof for storage of heat and coolness in appropriate seasons. During winter, underground water is circulated through specially designed pipe matrix imbeded in the roof slab and through radiant wall panels.

  4. IEA solar: Working toward greater cost-effectiveness, report of the International Energy Agency Solar Heating and Cooling Programme

    NASA Astrophysics Data System (ADS)

    Blum, S.

    1986-02-01

    This is the 1985 Annual Report of the International Energy Agency Solar Heating and Cooling (SHC) Program. The format of the report has been changed substantially from that of previous years. In addition, the report has been given a special theme: Working Toward Greater Cost-Effectiveness. Section 2 of this report, the special theme chapter, discusses the contributions of the cooperative activities to achieving more cost-effective solar heating and cooling systems. A report on the progress and accomplishments during 1985 of the current tasks is found in Section 3. Section 4, Appendix, contains a description of each of the tasks as background information for those unfamiliar with all or parts of the program. Finally, the Appendix also contains information on IEA SHC reports, meetings, Executive Committee Members and task technical participants.

  5. Direct observations of plasma upflows and condensation in a catastrophically cooling solar transition region loop

    SciTech Connect

    Orange, N. B.; Chesny, D. L.; Oluseyi, H. M.; Hesterly, K.; Patel, M.; Champey, P.

    2013-12-01

    Minimal observational evidence exists for fast transition region (TR) upflows in the presence of cool loops. Observations of such occurrences challenge notions of standard solar atmospheric heating models as well as their description of bright TR emission. Using the EUV Imaging Spectrometer on board Hinode, we observe fast upflows (v {sub λ} ≤ –10 km s{sup –1}) over multiple TR temperatures (5.8 ≤log T ≤ 6.0) at the footpoint sites of a cool loop (log T ≤ 6.0). Prior to cool loop energizing, asymmetric flows of +5 km s{sup –1} and –60 km s{sup –1} are observed at footpoint sites. These flows, speeds, and patterns occur simultaneously with both magnetic flux cancellation (at the site of upflows only) derived from the Solar Dynamics Observatory's Helioseismic Magnetic Imager's line-of-sight magnetogram images, and a 30% mass influx at coronal heights. The incurred non-equilibrium structure of the cool loop leads to a catastrophic cooling event, with subsequent plasma evaporation indicating that the TR is the heating site. From the magnetic flux evolution, we conclude that magnetic reconnection between the footpoint and background field is responsible for the observed fast TR plasma upflows.

  6. Characterization of a starch based desiccant wheel dehumidifier

    NASA Astrophysics Data System (ADS)

    Beery, Kyle Edward

    Starch, cellulose, and hemicellulose have an affinity for water, and adsorb water vapor from air. Materials made from combinations of these biobased sugar polymers also have been found to possess adsorptive properties. An interesting possible application of these starch-based adsorbents is the desiccant wheel dehumidifier. The desiccant wheel dehumidifier is used in conjunction with a standard air conditioning system. In this process, ambient air is passed through a stationary section while a wheel packed with desiccant rotates through that section. The desiccant adsorbs humidity (latent load) from the air, and the air conditioning system then cools the air (sensible load). Several starch based adsorbents were developed and tested for adsorptive capacity in a new high throughput screening system. The best formulations from the high throughput screening system, also taking into account economic considerations and structural integrity, were considered for use in the desiccant wheel dehumidifier. A suitable adsorbent was chosen and formulated into a matrix structure for the desiccant wheel system. A prototype desiccant wheel system was constructed and the performance was investigated under varying regeneration temperatures and rotation speeds. The results from the experiments showed that the starch based desiccant wheel dehumidification system does transfer moisture from the inlet process stream to the outlet regeneration stream. The DESSIM model was modified for the starch based adsorbent and compared to the experimental results. Also, the results when the wheel parameters were varied were compared to the predicted results from the model. The results given by the starch based desiccant wheel system show the desired proof of concept.

  7. Effect of solar radiation on the performance of cross flow wet cooling tower in hot climate of Iran

    NASA Astrophysics Data System (ADS)

    Banooni, Salem; Chitsazan, Ali

    2016-11-01

    In some cities such as Ahvaz-Iran, the solar radiation is very high and the annual-mean-daily of the global solar radiation is about 17.33 MJ m2 d-1. Solar radiation as an external heat source seems to affect the thermal performance of the cooling towers. Usually, in modeling cooling tower, the effects of solar radiation are ignored. To investigate the effect of sunshade on the performance and modeling of the cooling tower, the experiments were conducted in two different states, cooling towers with and without sunshade. In this study, the Merkel's approach and finite difference technique are used to predict the thermal behavior of cross flow wet cooling tower without sunshade and the results are compared with the data obtained from the cooling towers with and without sunshade. Results showed that the sunshade is very efficient and it reduced the outlet water temperature, the approach and the water exergy of the cooling tower up to 1.2 °C, 15 and 1.1 %, respectively and increased the range and the efficiency of the cooling tower up to 29 and 37 %, respectively. Also, the sunshade decreased the error between the experimental data of the cooling tower with sunshade and the modeling results of the cooling tower without sunshade 1.85 % in average.

  8. Desiccation tolerance of prokaryotes.

    PubMed Central

    Potts, M

    1994-01-01

    The removal of cell-bound water through air drying and the addition of water to air-dried cells are forces that have played a pivotal role in the evolution of the prokaryotes. In bacterial cells that have been subjected to air drying, the evaporation of free cytoplasmic water (Vf) can be instantaneous, and an equilibrium between cell-bound water (Vb) and the environmental water (vapor) potential (psi wv) may be achieved rapidly. In the air-dried state some bacteria survive only for seconds whereas others can tolerate desiccation for thousands, perhaps millions, of years. The desiccated (anhydrobiotic) cell is characterized by its singular lack of water--with contents as low as 0.02 g of H2O g (dry weight)-1. At these levels the monolayer coverage by water of macromolecules, including DNA and proteins, is disturbed. As a consequence the mechanisms that confer desiccation tolerance upon air-dried bacteria are markedly different from those, such as the mechanism of preferential exclusion of compatible solutes, that preserve the integrity of salt-, osmotically, and freeze-thaw-stressed cells. Desiccation tolerance reflects a complex array of interactions at the structural, physiological, and molecular levels. Many of the mechanisms remain cryptic, but it is clear that they involve interactions, such as those between proteins and co-solvents, that derive from the unique properties of the water molecule. A water replacement hypothesis accounts for how the nonreducing disaccharides trehalose and sucrose preserve the integrity of membranes and proteins. Nevertheless, we have virtually no insight into the state of the cytoplasm of an air-dried cell. There is no evidence for any obvious adaptations of proteins that can counter the effects of air drying or for the occurrence of any proteins that provide a direct and a tangible contribution to cell stability. Among the prokaryotes that can exist as anhydrobiotic cells, the cyanobacteria have a marked capacity to do so. One

  9. Solar heating and cooling of residential buildings: design of systems, 1980 edition

    SciTech Connect

    1980-09-01

    This manual was prepared primarily for use in conducting a practical training course on the design of solar heating and cooling systems for residential and small office buildings, but may also be useful as a general reference text. The content level is appropriate for persons with different and varied backgrounds, although it is assumed that readers possess a basic understanding of heating, ventilating, and air-conditioning systems of conventional (non-solar) types. This edition is a revision of the manual with the same title, first printed and distributed by the US Government Printing Office in October 1977. The manual has been reorganized, new material has been added, and outdated information has been deleted. Only active solar systems are described. Liquid and air-heating solar systems for combined space and service water heating or service water heating are included. Furthermore, only systems with proven experience are discussed to any extent.

  10. Coordination and management tasks for the IEA solar heating and cooling program and CCMS solar energy pilot study. Final report

    SciTech Connect

    Blum, S B; Kennish, W J

    1980-10-01

    The objective of the project entitled, Coordination/Management Tasks for the IEA Solar Heating and Cooling Program and CCMS Solar Energy Pilot Study, was to provide support to DOE in connection with the afore-named multilateral cooperative projects. The work included both management assistance for the overall IEA and CCMS projects and technical involvement in IEA Task I, particularly the solar system performance validation effort. The final report, covering the period March 15, 1979 - September 30, 1980, provides an overview of the accomplishments under this contract and gives conclusions and recommendations for future work. Also included in this document is the final project status report for the period May 15, 1980 to September 30, 1980.

  11. Solar heating and cooling system installed at Columbus, Ohio. Final report

    SciTech Connect

    Coy, R. G.; Braden, R. P.

    1980-09-01

    The Solar Energy System installed at Columbus Technical Institute, Columbus, Ohio was installed as a part of a new construction of a college building. The building will house classrooms and laboratories, administrative offices and three lecture halls. The Solar Energy System consists of 4096 square feet (128 panels) Owens/Illinois Evacuated Glass Tube Collector Subsystem, and a 5000 gallon steel tank below ground storage system, hot water is circulated between the collectors and storage tank, passing through a water/lithium bromide absorption chiller to cool the building. Extracts from the site files specification references, drawings, installation, operation and maintenance instructions are included.

  12. What are the relative roles of heating and cooling in generating solar wind temperature anisotropies?

    PubMed

    Maruca, B A; Kasper, J C; Bale, S D

    2011-11-11

    Temperature anisotropy in the solar wind results from a combination of mechanisms of anisotropic heating (e.g., cyclotron-resonant heating and dissipation of kinetic Alfvén waves) and cooling (e.g., Chew-Goldberger-Low double-adiabatic expansion). In contrast, anisotropy-driven instabilities such as the cyclotron, mirror, and firehose instabilities limit the allowable departure of the plasma from isotropy. This study used data from the Faraday cups on the Wind spacecraft to examine scalar temperature and temperature components of protons. Plasma unstable to the mirror or firehose instability was found to be about 3-4 times hotter than stable plasma. Since anisotropy-driven instabilities are not understood to heat the plasma, these results suggest that heating processes are more effective than cooling processes at creating and maintaining proton temperature anisotropy in the solar wind.

  13. Performance criteria for solar heating and cooling systems in residential buildings

    NASA Astrophysics Data System (ADS)

    1982-09-01

    This performance criteria, developed for the Department of Housing and Urban Development, is a baseline document for criteria and standards for the design, development, technical evaluation, and procurement of solar heating and cooling systems for residential buildings in accordance with the requirements of Section 8 of Public Law 93-409, the Solar Heating and Cooling Demonstration Act of 1974. The document is intended to establish minimum levels of performance with regard to health and safety and the various aspects of technical performance. The criteria for health and safety put primary emphasis on compliance with existing codes and standards. The criteria on thermal and mechanical performance, durability/reliability and operation/servicing present performance requirements considered to be representative of acceptable levels.

  14. Summary of NASA-Lewis Research Center solar heating and cooling and wind energy programs

    NASA Technical Reports Server (NTRS)

    Vernon, R. W.

    1975-01-01

    NASA is planning to construct and operate a solar heating and cooling system in conjunction with a new office building being constructed at Langley Research Center. The technology support for this project will be provided by a solar energy program underway at NASA's Lewis Research Center. The solar program at Lewis includes: testing of solar collectors with a solar simulator, outdoor testing of collectors, property measurements of selective and nonselective coatings for solar collectors, and a solar model-systems test loop. NASA-Lewis has been assisting the National Science Foundation and now the Energy Research and Development Administration in planning and executing a national wind energy program. The areas of the wind energy program that are being conducted by Lewis include: design and operation of a 100 kW experimental wind generator, industry-designed and user-operated wind generators in the range of 50 to 3000 kW, and supporting research and technology for large wind energy systems. An overview of these activities is provided.

  15. A high-tech low-energy house with solar thermal and sky radiation cooling

    SciTech Connect

    Saitoh, Takeo; Fujino, Tetsuji; Suzuki, Masanori

    1998-07-01

    A unique energy-independent house (HARBEMAN HOUSE; HARmony BEtween Man And Nature) incorporating solar thermal, underground coolness, sky radiation cooling, photovoltaic electricity generation and rain water was built in Sendai, Japan on July, 1996. The average solar energy received on a horizontal surface in January is 7900 kJ/m{sup 2}/day. This paper reports the experimental results since September 1996 to date. The annual variations of water temperature in the underground main tank, heating/cooling/domestic hot water demands, collected and emitted heats by solar collector and sky radiator, were obtained by the measured data. The paper also clarifies the method of computer simulation results for the HARBEMAN HOUSE and its results compared with the annual experimental data. The proposed HARBEMAN house, which meets almost all its energy demands, including space heating and cooling, domestic hot water, electricity generated by photovoltaic cell and rainwater for standard Japanese homes. The proposed system has two operational modes: (i) a long-term thermal energy storage mode extending from September to next March and (ii) a long-term cool storage mode extending from April to August. The system is intended to utilize as little energy as possible to collect and emit the heat. This paper also clarifies the primary energy consumption, the external costs (externalities) and the effect for reduction of carbon dioxide (CO2) emissions. The primary energy consumption and carbon dioxide emissions of the proposed house are only one-tenth of these of the conventional standard house. Finally, this paper validates the external costs of this house, which have been intensively discussed in recent years in European countries. The present energy-sufficient house will be promising in the 21st century to reduce carbon dioxide emissions, which will be one of the key factors for mitigating global warming.

  16. System design and installation for RS600 programmable control system for solar heating and cooling

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Procedures for installing, operating, and maintaining a programmable control system which utilizes a F8 microprocessor to perform all timing, control, and calculation functions in order to customize system performance to meet individual requirements for solar heating, combined heating and cooling, and/or hot water systems are described. The manual discusses user configuration and options, displays, theory of operation, trouble-shooting procedures, and warranty and assistance. Wiring lists, parts lists, drawings, and diagrams are included.

  17. 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.

  18. The design of a solar energy collection system to augment heating and cooling for a commercial office building

    NASA Technical Reports Server (NTRS)

    Basford, R. C.

    1977-01-01

    Analytical studies supported by experimental testing indicate that solar energy can be utilized to heat and cool commercial buildings. In a 50,000 square foot one-story office building at the Langley Research Center, 15,000 square feet of solar collectors are designed to provide the energy required to supply 79 percent of the building heating needs and 52 percent of its cooling needs. The experience gained from the space program is providing the technology base for this project. Included are some of the analytical studies made to make the building design changes necessary to utilize solar energy, the basic solar collector design, collector efficiencies, and the integrated system design.

  19. Evidence for Solar Cycle Influence on the Infrared Energy Budget and Radiative Cooling of the Thermosphere

    NASA Technical Reports Server (NTRS)

    Mlynczak, Martin G.; Martin-Torres, F. Javier; Marshall, B. Thomas; Thompson, R. Earl; Williams, Joshua; Turpin, TImothy; Kratz, D. P.; Russell, James M.; Woods, Tom; Gordley, Larry L.

    2007-01-01

    We present direct observational evidence for solar cycle influence on the infrared energy budget and radiative cooling of the thermosphere. By analyzing nearly five years of data from the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument, we show that the annual mean infrared power radiated by the nitric oxide (NO) molecule at 5.3 m has decreased by a factor of 2.9. This decrease is correlated (r = 0.96) with the decrease in the annual mean F10.7 solar index. Despite the sharp decrease in radiated power (which is equivalent to a decrease in the vertical integrated radiative cooling rate), the variability of the power as given in the standard deviation of the annual means remains approximately constant. A simple relationship is shown to exist between the infrared power radiated by NO and the F10.7 index, thus providing a fundamental relationship between solar activity and the thermospheric cooling rate for use in thermospheric models. The change in NO radiated power is also consistent with changes in absorbed ultraviolet radiation over the same time period.

  20. Analysis of the solar powered/fuel assisted Rankine cycle cooling system. Phase 1: Revision

    NASA Astrophysics Data System (ADS)

    Lior, N.; Koai, K.; Yeh, H.

    1985-04-01

    The subject of this analysis is a solar cooling system which consists of a conventional open-compressor chiller, driven by a novel hybrid steam Rankine cycle. Steam is generated by the use of solar energy collected at about 100C, and it is then superheated to about 600C in a fossil-fuel fired superheater. The steam drives a novel counter-rotating turbine, some of the heat from it is regenerated, and it is then condensed. Thermal storage is implemented as an integral part of the cycle, by means of hot-water which is flashed to steam when needed for driving the turbine. For the solar energy input, both evacuated and double-glazed flat-plate collectors were considered. A comprehensive computer program was developed to analyze the operation and performance of the entire power/cooling system. Each component was described by a separate subroutine to compute its performance from basic principles, and special attention was given to the parasitic losses, including pumps, fans and pressure drops in the piping and heat exchangers, and to describe the off-design performance of the components. The thermophysical properties of the fluids used are also described in separate subroutines. Transient simulation of the entire system was performed on an hourly basis over a cooling season in two representative climatic regions (Washington, DC, and Phoenix, AZ) for a number of system configurations.

  1. Solar thermoelectric cooling using closed loop heat exchangers with macro channels

    NASA Astrophysics Data System (ADS)

    Atta, Raghied M.

    2017-01-01

    In this paper we describe the design, analysis and experimental study of an advanced coolant air conditioning system which cools or warms airflow using thermoelectric (TE) devices powered by solar cells. Both faces of the TE devices are directly connected to closed-loop highly efficient channels plates with macro scale channels and liquid-to-air heat exchangers. The hot side of the system consists of a pump that moves a coolant through the hot face of the TE modules, a radiator that drives heat away into the air, and a fan that transfer the heat over the radiator by forced convection. The cold side of the system consists also of a pump that moves coolant through the cold face of the TE modules, a radiator that drives cold away into the air, and a fan that blows cold air off the radiator. The system was integrated with solar panels, tested and its thermal performance was assessed. The experimental results verify the possibility of heating or cooling air using TE modules with a relatively high coefficient of performance (COP). The system was able to cool a closed space of 30 m3 by 14 °C below ambient within 90 min. The maximum COP of the whole system was 0.72 when the TE modules were running at 11.2 Å and 12 V. This improvement in the system COP over the air cooled heat sink is due to the improvement of the system heat exchange by means of channels plates.

  2. Low-Cost "Vacuum Desiccator"

    NASA Astrophysics Data System (ADS)

    Sweet, Frederick

    2004-10-01

    Described are individualized, low-cost, and safe desiccators that can be efficiently and rapidly made with an inexpensive kitchen aid sold for shrink-wrapping food. The device can be used for enclosing small vials or bottles and also jars that are too large to be placed in conventional glass or plastic desiccators. This shrink-wrapping device is proposed for producing "vacuum desiccators" in large undergraduate chemistry laboratories or in graduate and research laboratories.

  3. Transient analysis and energy optimization of solar heating and cooling systems in various configurations

    SciTech Connect

    Calise, F.; Dentice d'Accadia, M.; Palombo, A.

    2010-03-15

    In this paper, a transient simulation model of solar-assisted heating and cooling systems (SHC) is presented. A detailed case study is also discussed, in which three different configurations are considered. In all cases, the SHC system is based on the coupling of evacuated solar collectors with a single-stage LiBr-H{sub 2}O absorption chiller, and a gas-fired boiler is also included for auxiliary heating, only during the winter season. In the first configuration, the cooling capacity of the absorption chiller and the solar collector area are designed on the basis of the maximum cooling load, and an electric chiller is used as the auxiliary cooling system. The second layout is similar to the first one, but, in this case, the absorption chiller and the solar collector area are sized in order to balance only a fraction of the maximum cooling load. Finally, in the third configuration, there is no electric chiller, and the auxiliary gas-fired boiler is also used in summer to feed the absorption chiller, in case of scarce solar irradiation. The simulation model was developed using the TRNSYS software, and included the analysis of the dynamic behaviour of the building in which the SHC systems were supposed to be installed. The building was simulated using a single-lumped capacitance model. An economic model was also developed, in order to assess the operating and capital costs of the systems under analysis. Furthermore, a mixed heuristic-deterministic optimization algorithm was implemented, in order to determine the set of the synthesis/design variables that maximize the energy efficiency of each configuration under analysis. The results of the case study were analyzed on monthly and weekly basis, paying special attention to the energy and monetary flows of the standard and optimized configurations. The results are encouraging as for the potential of energy saving. On the contrary, the SHC systems appear still far from the economic profitability: however, this is

  4. Solar heating and cooling R and D program coordination support. Final report, October 1, 1980-September 30, 1983

    SciTech Connect

    Not Available

    1984-01-01

    The objective of the project was to support the US Department of Energy's international R and D activities in the solar heating and cooling area. The cooperative programs were of two types: bilateral (involving the US and one other country) and multilateral (involving the US and several other countries). The multilateral programs supported under this contract were: International Energy Agency Solar Heating and Cooling Program; and NATO/CCMS Solar Energy Pilot Study. Solar heating and cooling projects under the following bilateral programs were supported: US/Mexico; US/Israel; and US/Spain. The assistance to DOE's Office of Solar Heat Technologies, consisted primarily of program management and coordination support, plus a smaller amount of technical support. This final report summarizes the work performed during the three years of this contract and the accomplishments.

  5. Experiments on solar photovoltaic power generation using concentrator and liquid cooling

    NASA Technical Reports Server (NTRS)

    Beam, B. H.; Hansen, C. F.

    1975-01-01

    Calculations and experimental data are presented leading to the development of a practical, economical solar photovoltaic power supply. The concept involves concentration of sunlight up to about 100 times normal solar intensity in a solar tracking collector and directing this to an array of solar cells. The cells are immersed in water circulated from a thermal reservoir which limits cell temperature rise to about 20 C above ambient during the day and which cools to ambient temperature during the night. Experiments were conducted on solar cells using a Fresnel lens for magnification, a telescope equatorial mount with clock drive, and tap water circulated through the solar cell holder cavity. Test results show that cells operate satisfactorily under these conditions. Power outputs achieved experimentally with cell optimized for 25 suns were linear with concentration to about 15 suns. Cells optimized for 100 suns were not available, but a corresponding linear relation of power output with concentration is anticipated. Test results have been used in a design analysis of the cost of systems utilizing this technique.

  6. National Program for Solar Heating and Cooling of Buildings. Project Date Summaries. Vol. I: Commercial and Residential Demonstrations.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    Three volumes present brief abstracts of projects funded by the Energy Research and Development Administration (ERDA) and conducted under the National Program for Solar Heating and Cooling of Buildings through July 1976. The overall federal program includes demonstrations of heating and/or combined cooling for residential and commercial buildings…

  7. Advanced glazing and associated materials for solar and building applications: International Energy Agency Solar Heating and Cooling Program Task 18

    NASA Astrophysics Data System (ADS)

    Hutchins, Michael G.

    1992-11-01

    Following a program definition phase of 2 years, Task 18 of the International Energy Agency Solar Heating & Cooling program commenced a 5 year research phase in April 1992. Task 18 investigates a wide range of advanced glazing materials and glazing systems which include monolithic and granular aerogels, transparent insulation materials, chromogenic materials, evacuated glazings, low-emittance coatings, solar collector covers, angular selective transmittance thin films, holographic and light guide materials, and frame and edge seal technology. In addition to materials-centered research, Task 18 concentrates on measurement of key glazing properties such as total energy transmittance, U-value, and spectral directional optical properties, and through the use of building energy analysis software tools the identification of appropriate applications, control strategies, and energy and environmental benefits to be derived from advanced glazing products. Fifteen OECD countries are participating in Task 18 which is led by the United Kingdom.

  8. Investigation of Absorption Cooling Application Powered by Solar Energy in the South Coast Region of Turkey

    NASA Astrophysics Data System (ADS)

    Babayigit, O.; Aksoy, M. H.; Ozgoren, M.; Solmaz, O.

    2013-04-01

    In this study, an absorption system using ammonia-water (NH3-H2O) solution has been theoretically examined in order to meet the cooling need of a detached building having 150 m2 floor area for Antalya, Mersin and Mugla provinces in Turkey. Hourly dynamic cooling load capacities of the building were determined by using Radiant Time Series (RTS) method in the chosen cities. For the analysis, hourly average meteorological data such as atmospheric air temperature and solar radiation belonging to the years 1998-2008 are used for performance prediction of the proposed system. Thermodynamic relations for each component of absorption cooling system is explained and coefficients of performance of the system are calculated. The maximum daily total radiation data were calculated as 7173 W/m2day on July 15, 7277 W/m2 day on July 19 and 7231 W/m2day on July 19 for Mersin, Antalya and Mugla, respectively on the 23° toward to south oriented panels from horizontal surface. The generator operating temperatures are considered between 90-130°C and the best result for 110°C is found the optimum degree for maximum coefficient of performance (COP) values at the highest solar radiation occurred time during the considered days for each province. The COP values varies between 0.521 and 0.530 for the provinces. In addition, absorber and condenser capacities and thermal efficiency for the absorption cooling system were calculated. The necessary evacuated tube collector area for the different provinces were found in the range of 45 m2 to 47 m2. It is shown that although the initial investment cost is higher for the proposed absorption cooling system, it is economically feasible because of its lower annual operation costs and can successfully be operated for the considered provinces.

  9. Influence of Ventilation Ratio on Desiccant Air Conditioning System's Efficiency Performance

    NASA Astrophysics Data System (ADS)

    Tran, Thien Nha; Akisawa, Atsushi; Kashiwagi, Takao; Hamamoto, Yoshinori

    Ventilation air is a concern for engineers since ventilated air controls indoor air contamination; additional ventilation, however, increases the energy consumption of buildings. The study investigates the energy efficiency performance of the desiccant dehumidification air conditioning system in the context of ventilation for a hot-humid climate such as summer in Japan. The investigation focuses on the variable ratio of ventilation air as required by the application of air conditioning system. The COP of the desiccant air conditioning system is determined. The evaluation is subsequently performed by comparing the desiccant based system with the conventional absorption cooling system and the vapor compression cooling system. Based on 12 desiccant rotor simulations, it is found that the desiccant regeneration temperature required varies between 47°C to 85°C as ventilation ratio increases from 0. 0 to 100%, and up to 52. 5°C as the ventilation ratio achieves 14%. The heat required for regenerating desiccant accounts for 55% and higher of the system's total heat consumption; the system is expected to be energy efficient by using wasted heat from the absorption chiller for desiccant regeneration; and its energy efficiency expands as the ratio of ventilation air rises above 15% compared with the conventional absorption cooling system. The energy efficiency also benefits as the ratio rises beyond 70% against the conventional vapor compression cooling system.

  10. A solar thermal cooling and heating system for a building: Experimental and model based performance analysis and design

    SciTech Connect

    Qu, Ming; Yin, Hongxi; Archer, David H.

    2010-02-15

    A solar thermal cooling and heating system at Carnegie Mellon University was studied through its design, installation, modeling, and evaluation to deal with the question of how solar energy might most effectively be used in supplying energy for the operation of a building. This solar cooling and heating system incorporates 52 m{sup 2} of linear parabolic trough solar collectors; a 16 kW double effect, water-lithium bromide (LiBr) absorption chiller, and a heat recovery heat exchanger with their circulation pumps and control valves. It generates chilled and heated water, dependent on the season, for space cooling and heating. This system is the smallest high temperature solar cooling system in the world. Till now, only this system of the kind has been successfully operated for more than one year. Performance of the system has been tested and the measured data were used to verify system performance models developed in the TRaNsient SYstem Simulation program (TRNSYS). On the basis of the installed solar system, base case performance models were programmed; and then they were modified and extended to investigate measures for improving system performance. The measures included changes in the area and orientation of the solar collectors, the inclusion of thermal storage in the system, changes in the pipe diameter and length, and various system operational control strategies. It was found that this solar thermal system could potentially supply 39% of cooling and 20% of heating energy for this building space in Pittsburgh, PA, if it included a properly sized storage tank and short, low diameter connecting pipes. Guidelines for the design and operation of an efficient and effective solar cooling and heating system for a given building space have been provided. (author)

  11. Recommended requirements to code officials for solar heating, cooling, and hot water systems. Model document for code officials on solar heating and cooling of buildings

    SciTech Connect

    1980-06-01

    These recommended requirements include provisions for electrical, building, mechanical, and plumbing installations for active and passive solar energy systems used for space or process heating and cooling, and domestic water heating. The provisions in these recommended requirements are intended to be used in conjunction with the existing building codes in each jurisdiction. Where a solar relevant provision is adequately covered in an existing model code, the section is referenced in the Appendix. Where a provision has been drafted because there is no counterpart in the existing model code, it is found in the body of these recommended requirements. Commentaries are included in the text explaining the coverage and intent of present model code requirements and suggesting alternatives that may, at the discretion of the building official, be considered as providing reasonable protection to the public health and safety. Also included is an Appendix which is divided into a model code cross reference section and a reference standards section. The model code cross references are a compilation of the sections in the text and their equivalent requirements in the applicable model codes. (MHR)

  12. Optimisation of concentrating solar cell systems with passive and active cooling

    NASA Astrophysics Data System (ADS)

    Blumenberg, J.

    1983-10-01

    Design considerations for concentrator solar cell arrays for space applications are reviewed, noting the restrictions on total mass that govern system selections. Consideration is given to systems with parabolic mirrors and Si and GaAs solar cells. Passive and active cooling systems for the arrays are discussed, as is the addition of a heat engine with a turbogenerator to utilize part of the waste heat of the cooling cycle. Attention is given to systems orbiting at 0.5, 1, and 3.5 AU from the sun. Flat panels are found to be more suitable for missions near the sun for Si solar cells, while GaAs cells with concentration are preferred to flat panel systems at all distances from the sun. Nuclear turboelectric systems are better than concentrator Si arrays at large distances from the sun, in terms of specific masses of the systems. The addition of a system to use waste heat is judged unfavorable from specific mass factors.

  13. Advanced phase change materials and systems for solar passive heating and cooling of residential buildings

    SciTech Connect

    Salyer, I.O.; Sircar, A.K.; Dantiki, S.

    1988-01-01

    During the last three years under the sponsorship of the DOE Solar Passive Division, the University of Dayton Research Institute (UDRI) has investigated four phase change material (PCM) systems for utility in thermal energy storage for solar passive heating and cooling applications. From this research on the basis of cost, performance, containment, and environmental acceptability, we have selected as our current and most promising series of candidate phase change materials, C-15 to C-24 linear crystalline alkyl hydrocarbons. The major part of the research during this contract period was directed toward the following three objectives. Find, test, and develop low-cost effective phase change materials (PCM) that melt and freeze sharply in the comfort temperature range of 73--77{degree}F for use in solar passive heating and cooling of buildings. Define practical materials and processes for fire retarding plasterboard/PCM building products. Develop cost-effective methods for incorporating PCM into building construction materials (concrete, plasterboard, etc.) which will lead to the commercial manufacture and sale of PCM-containing products resulting in significant energy conservation.

  14. Multi-criteria decision analysis of concentrated solar power with thermal energy storage and dry cooling.

    PubMed

    Klein, Sharon J W

    2013-12-17

    Decisions about energy backup and cooling options for parabolic trough (PT) concentrated solar power have technical, economic, and environmental implications. Although PT development has increased rapidly in recent years, energy policies do not address backup or cooling option requirements, and very few studies directly compare the diverse implications of these options. This is the first study to compare the annual capacity factor, levelized cost of energy (LCOE), water consumption, land use, and life cycle greenhouse gas (GHG) emissions of PT with different backup options (minimal backup (MB), thermal energy storage (TES), and fossil fuel backup (FF)) and different cooling options (wet (WC) and dry (DC). Multicriteria decision analysis was used with five preference scenarios to identify the highest-scoring energy backup-cooling combination for each preference scenario. MB-WC had the highest score in the Economic and Climate Change-Economy scenarios, while FF-DC and FF-WC had the highest scores in the Equal and Availability scenarios, respectively. TES-DC had the highest score for the Environmental scenario. DC was ranked 1-3 in all preference scenarios. Direct comparisons between GHG emissions and LCOE and between GHG emissions and land use suggest a preference for TES if backup is require for PT plants to compete with baseload generators.

  15. Large Eddy Simulation of complex sidearms subject to solar radiation and surface cooling.

    PubMed

    Dittko, Karl A; Kirkpatrick, Michael P; Armfield, Steven W

    2013-09-15

    Large Eddy Simulation (LES) is used to model two lake sidearms subject to heating from solar radiation and cooling from a surface flux. The sidearms are part of Lake Audrey, NJ, USA and Lake Alexandrina, SA, Australia. The simulation domains are created using bathymetry data and the boundary is modelled with an Immersed Boundary Method. We investigate the cooling and heating phases with separate quasi-steady state simulations. Differential heating occurs in the cavity due to the changing depth. The resulting temperature gradients drive lateral flows. These flows are the dominant transport process in the absence of wind. Study in this area is important in water quality management as the lateral circulation can carry particles and various pollutants, transporting them to and mixing them with the main lake body.

  16. 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.

  17. Cool roofs with high solar reflectance for the welfare of dairy farming animals

    NASA Astrophysics Data System (ADS)

    Santunione, G.; Libbra, A.; Muscio, A.

    2017-01-01

    Ensuring livestock welfare in dairy farming promotes the production capacity of the animals in terms of both quantity and quality. In welfare conditions, the animals can produce at their full potential. For the dairy cattle the most debilitating period of the year is summer, when the stress arising from overheating induces physiological alterations that compromise the animals’ productivity. In this study, the summer discomfort of dairy animals is primarily quantified and the production loss is quantified versus the Temperature Humidity Index (THI), which correlates the values of temperature and relative humidity to the thermal stress. In order to reduce or eliminate such thermal stress, it is then proposed to coat the roof of the stables with a paint having high solar reflectance and thermal emittance, that is a cool roof product. This type of roofing solution can considerably limit the overheating of stables caused by solar radiation, thus providing a positive impact on the animals’ welfare and improving significantly their productivity in summer.

  18. Desiccant outdoor air preconditioners maximize heat recovery ventilation potentials

    SciTech Connect

    Meckler, M.

    1995-12-31

    Microorganisms are well protected indoors by the moisture surrounding them if the relative humidity is above 70%. They can cause many acute diseases, infections, and allergies. Humidity also has an effect on air cleanliness and causes the building structure and its contents to deteriorate. Therefore, controlling humidity is a very important factor to human health and comfort and the structural longevity of a building. To date, a great deal of research has been done, and is continuing, in the use of both solid and liquid desiccants. This paper introduces a desiccant-assisted system that combines dehumidification and mechanical refrigeration by means of a desiccant preconditioning module that can serve two or more conventional air-conditioning units. It will be demonstrated that the proposed system, also having indirect evaporative cooling within the preconditioning module, can reduce energy consumption and provide significant cost savings, independent humidity and temperature control, and, therefore, improved indoor air quality and enhanced occupant comfort.

  19. Measurement uncertainty of adsorption testing of desiccant materials

    SciTech Connect

    Bingham, C E; Pesaran, A A

    1988-12-01

    The technique of measurement uncertainty analysis as described in the current ANSI/ASME standard is applied to the testing of desiccant materials in SERI`s Sorption Test Facility. This paper estimates the elemental precision and systematic errors in these tests and propagates them separately to obtain the resulting uncertainty of the test parameters, including relative humidity ({plus_minus}.03) and sorption capacity ({plus_minus}.002 g/g). Errors generated by instrument calibration, data acquisition, and data reduction are considered. Measurement parameters that would improve the uncertainty of the results are identified. Using the uncertainty in the moisture capacity of a desiccant, the design engineer can estimate the uncertainty in performance of a dehumidifier for desiccant cooling systems with confidence. 6 refs., 2 figs., 8 tabs.

  20. Solar heating, cooling, and domestic hot water system installed at Kaw Valley State Bank and Trust Company, Topeka, Kansas

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The building has approximately 5600 square feet of conditioned space. Solar energy was used for space heating, space cooling, and preheating domestic hot water (DHW). The solar energy system had an array of evacuated tube-type collectors with an area of 1068 square feet. A 50/50 solution of ethylene glycol and water was the transfer medium that delivered solar energy to a tube-in-shell heat exchanger that in turn delivered solar heated water to a 1100 gallon pressurized hot water storage tank. When solar energy was insufficient to satisfy the space heating and/or cooling demand, a natural gas-fired boiler provided auxiliary energy to the fan coil loops and/or the absorption chillers. Extracts from the site files, specification references, drawings, and installation, operation and maintenance instructions are presented.

  1. Pricing the urban cooling benefits of solar panel deployment in Sydney, Australia

    NASA Astrophysics Data System (ADS)

    Ma, S.; Goldstein, M.; Pitman, A. J.; Haghdadi, N.; MacGill, I.

    2017-03-01

    Cities import energy, which in combination with their typically high solar absorption and low moisture availability generates the urban heat island effect (UHI). The UHI, combined with human-induced warming, makes our densely populated cities particularly vulnerable to climate change. We examine the utility of solar photovoltaic (PV) system deployment on urban rooftops to reduce the UHI, and we price one potential value of this impact. The installation of PV systems over Sydney, Australia reduces summer maximum temperatures by up to 1 °C because the need to import energy is offset by local generation. This offset has a direct environmental benefit, cooling local maximum temperatures, but also a direct economic value in the energy generated. The indirect benefit associated with the temperature changes is between net AUD$230,000 and $3,380,000 depending on the intensity of PV systems deployment. Therefore, even very large PV installations will not offset global warming, but could generate enough energy to negate the need to import energy, and thereby reduce air temperatures. The energy produced, and the benefits of cooling beyond local PV installation sites, would reduce the vulnerability of urban populations and infrastructure to temperature extremes.

  2. Pricing the urban cooling benefits of solar panel deployment in Sydney, Australia

    PubMed Central

    Ma, S.; Goldstein, M.; Pitman, A. J.; Haghdadi, N.; MacGill, I.

    2017-01-01

    Cities import energy, which in combination with their typically high solar absorption and low moisture availability generates the urban heat island effect (UHI). The UHI, combined with human-induced warming, makes our densely populated cities particularly vulnerable to climate change. We examine the utility of solar photovoltaic (PV) system deployment on urban rooftops to reduce the UHI, and we price one potential value of this impact. The installation of PV systems over Sydney, Australia reduces summer maximum temperatures by up to 1 °C because the need to import energy is offset by local generation. This offset has a direct environmental benefit, cooling local maximum temperatures, but also a direct economic value in the energy generated. The indirect benefit associated with the temperature changes is between net AUD$230,000 and $3,380,000 depending on the intensity of PV systems deployment. Therefore, even very large PV installations will not offset global warming, but could generate enough energy to negate the need to import energy, and thereby reduce air temperatures. The energy produced, and the benefits of cooling beyond local PV installation sites, would reduce the vulnerability of urban populations and infrastructure to temperature extremes. PMID:28262843

  3. Pricing the urban cooling benefits of solar panel deployment in Sydney, Australia.

    PubMed

    Ma, S; Goldstein, M; Pitman, A J; Haghdadi, N; MacGill, I

    2017-03-06

    Cities import energy, which in combination with their typically high solar absorption and low moisture availability generates the urban heat island effect (UHI). The UHI, combined with human-induced warming, makes our densely populated cities particularly vulnerable to climate change. We examine the utility of solar photovoltaic (PV) system deployment on urban rooftops to reduce the UHI, and we price one potential value of this impact. The installation of PV systems over Sydney, Australia reduces summer maximum temperatures by up to 1 °C because the need to import energy is offset by local generation. This offset has a direct environmental benefit, cooling local maximum temperatures, but also a direct economic value in the energy generated. The indirect benefit associated with the temperature changes is between net AUD$230,000 and $3,380,000 depending on the intensity of PV systems deployment. Therefore, even very large PV installations will not offset global warming, but could generate enough energy to negate the need to import energy, and thereby reduce air temperatures. The energy produced, and the benefits of cooling beyond local PV installation sites, would reduce the vulnerability of urban populations and infrastructure to temperature extremes.

  4. Elemental abundances in atmospheres of cool dwarfs with solar-like activity

    NASA Astrophysics Data System (ADS)

    Antipova, L. I.; Boyarchuk, A. A.

    2016-01-01

    The elemental abundances in the atmosphere of the red dwarf HD 32147, which belongs to the HR 1614 moving groups, are analyzed. The atmospheric parameters determined from spectroscopic data (the condition of equal abundances for neutral and ionized atoms of a given element) differ considerably from those derived from photometry and parallax data. The abundances of several elements are also anomalous, with the anomaly increasing with decreasing ionization potential. It is concluded that this star is a red dwarf displaying solar-like activity; i.e., having dark (cool) spots on its surface, which may sometimes be considerable in size. Modeling synthetic spectra of stars with cool spots on their surfaces, with the spectral lines consisting of two components formed in media with different temperatures, indicate that the spectroscopic atmospheric parameters derived in such cases are incorrect; this can also explain the observed dependence of the elemental abundances on the corresponding ionization potentials. This leads to the conclusion thatHD32147 is indeed a star with solar-like activity. Several other such stars considered as examples display the same anomalies as those of HD 32147. These modeling results are also valid for Ap and Am stars, and are able to explain short-wavelength observations of the Sun and some stars (the FIP effect).

  5. Experimental and theoretical analysis of a hybrid solar thermoelectric generator with forced convection cooling

    NASA Astrophysics Data System (ADS)

    Sundarraj, Pradeepkumar; Taylor, Robert A.; Banerjee, Debosmita; Maity, Dipak; Sinha Roy, Susanta

    2017-01-01

    Hybrid solar thermoelectric generators (HSTEGs) have garnered significant research attention recently due to their potential ability to cogenerate heat and electricity. In this paper, theoretical and experimental investigations of the electrical and thermal performance of a HSTEG system are reported. In order to validate the theoretical model, a laboratory scale HSTEG system (based on forced convection cooling) is developed. The HSTEG consists of six thermoelectric generator modules, an electrical heater, and a stainless steel cooling block. Our experimental analysis shows that the HSTEG is capable of producing a maximum electrical power output of 4.7 W, an electrical efficiency of 1.2% and thermal efficiency of 61% for an average temperature difference of 92 °C across the TEG modules with a heater power input of 382 W. These experimental results of the HSTEG system are found to be in good agreement with the theoretical prediction. This experimental/theoretical analysis can also serve as a guide for evaluating the performance of the HSTEG system with forced convection cooling.

  6. Plate coil thermal test bench for the Daniel K. Inouye Solar Telescope (DKIST) carousel cooling system

    NASA Astrophysics Data System (ADS)

    Phelps, LeEllen; Murga, Gaizka; Montijo, Guillermo; Hauth, David

    2014-08-01

    Analyses have shown that even a white-painted enclosure requires active exterior skin-cooling systems to mitigate dome seeing which is driven by thermal nonuniformities that change the refractive index of the air. For the Daniel K. Inouye Solar Telescope (DKIST) Enclosure, this active surface temperature control will take the form of a system of water cooled plate coils integrated into the enclosure cladding system. The main objective of this system is to maintain the surface temperature of the enclosure as close as possible to, but always below, local ambient temperature in order to mitigate this effect. The results of analyses using a multi-layer cladding temperature model were applied to predict the behavior of the plate coil cladding system and ultimately, with safety margins incorporated into the resulting design thermal loads, the detailed designs. Construction drawings and specifications have been produced. Based on these designs and prior to procurement of the system components, a test system was constructed in order to measure actual system behavior. The data collected during seasonal test runs at the DKIST construction site on Haleakalā are used to validate and/or refine the design models and construction documents as appropriate. The test fixture was also used to compare competing hardware, software, components, control strategies, and configurations. This paper outlines the design, construction, test protocols, and results obtained of the plate coil thermal test bench for the DKIST carousel cooling system.

  7. Integrated energy, economic, and environmental assessment for the optimal solar absorption cooling and heating system

    NASA Astrophysics Data System (ADS)

    Hang, Yin

    Buildings in the United States are responsible for 41% of the primary energy use and 30% of carbon dioxide emissions. Due to mounting concerns about climate change and resource depletion, meeting building heating and cooling demand with renewable energy has attracted increasing attention in the energy system design of green buildings. One of these approaches, the solar absorption cooling and heating (SACH) technology can be a key solution to addressing the energy and environmental challenges. SACH system is an integration of solar thermal heating system and solar thermal driven absorption cooling system. So far, SACH systems still remain at the demonstration and testing stage due to not only its high cost but also complicated system characteristics. This research aims to develop a methodology to evaluate the life cycle energy, economic and environmental performance of SACH systems by high-fidelity simulations validated by experimental data. The developed methodology can be used to assist the system design. In order to achieve this goal, the study includes four objectives as follows: * Objective 1: Develop the evaluation model for the SACH system. The model includes three aspects: energy, economy, and environment from a life cycle point of view. * Objective 2: Validate the energy system model by solar experiments performance data. * Objective 3: Develop a fast and effective multi-objective optimization methodology to find the optimal system configuration which achieves the maximum system benefits on energy, economy and environment. Statistic techniques are explored to reveal the relations between the system key parameters and the three evaluation targets. The Pareto front is generated by solving this multi-objective optimization problem. * Objective 4: Apply the developed assessment methodology to different building types and locations. Furthermore, this study considered the influence of the input uncertainties on the overall system performance. The sensitivity

  8. Review of Desiccant Dehumidification Technology

    SciTech Connect

    Pesaran, A. A.

    1994-10-01

    This paper overviews applications of desiccant technology for dehumidifying commercial and institutional buildings. Because of various market, policy, and regulatory factors, this technology is especially attractive for dehumidification applications in the I990s.

  9. Performance evaluation of single-glazed and double glazed collectors/regenerators for an open cycle absorption solar cooling system

    SciTech Connect

    Yang, R.; Wang, P.L.

    1998-07-01

    Feasibility for an open-cycle absorption solar cooling system operated in Kaohsiung, Taiwan is studied via a computer simulation program using previous obtained experimental correlations for the collector/regenerator (C/R) performance and the TMY data of Kaohsiung, Taiwan. Three C/R models are considered in this study. They are the natural and the forced convection single-glazed Cs/Rs and the forced convection double-glazed C/R. The effects of the C/R area, the C/R solution flow rate, the solution storage, the chilled water temperature and the daily cooling demand on the system performance in terms of seasonal solar fraction are studied and discussed. The results show that the solar C/R is the key component of the cooling system and the open-cycle absorption system is a sound solar cooling system. It is shown that the double glazed forced convection C/R gives a better system performance. The simulation study is to evaluate the seasonal solar fraction, which is defined as F=(solar cooling load)/(total cooling load) Firstly, all three C/R models are simulated under the base case conditions. The seasonal averaged solar fraction for three models are found to be 0.7, 0.75 and 0.79, respectively, while the corresponding seasonal averaged C/R efficiencies are 15.7%, 18.4% and 20.6%. The double-glazed forced convection system performs better than the other two systems. This is consistent with the results of previous experimental studies for the C/R. A nearly linear relationship between the C/R efficiency and the solar fraction is shown. The solar fraction increases slightly with the solution storage volume for the natural convection case, but it is much more sensitive to the solution storage for the forced convection system. The solar fraction is relatively insensitive to the C/R area after a critical value is reached. A similar dependence is also found in other solar absorption air conditioning system alternatives.

  10. Solar heating, cooling and domestic hot water system installed at Columbia Gas System Service Corporation, Columbus, Ohio

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The solar energy system installed in the building has 2,978 sq ft of single axis tracking, concentrating collectors and provides solar energy for space heating, space cooling and domestic hot water. A 1,200,000 Btu/hour water tube gas boiler provides hot water for space heating. Space cooling is provided by a 100 ton hot water fired absorption chiller. Domestic hot water heating is provided by a 50 gallon natural gas domestic storage water heater. Extracts from the site files, specification references, drawings, installation, operation and maintenance instructions are included.

  11. Low-Flow Liquid Desiccant Air Conditioning: General Guidance and Site Considerations

    SciTech Connect

    Kozubal, E.; Herrmann, L.; Deru, M.; Clark, J.

    2014-09-01

    Dehumidification or latent cooling in buildings is an area of growing interest that has been identified as needing more research and improved technologies for higher performance. Heating, ventilating, and air-conditioning (HVAC) systems typically expend excessive energy by using overcool-and-reheat strategies to dehumidify buildings. These systems first overcool ventilation air to remove moisture and then reheat the air to meet comfort requirements. Another common strategy incorporates solid desiccant rotors that remove moisture from the air more efficiently; however, these systems increase fan energy consumption because of the high airside pressure drop of solid desiccant rotors and can add heat of absorption to the ventilation air. Alternatively, liquid desiccant air-conditioning (LDAC) technology provides an innovative dehumidification solution that: (1) eliminates the need for overcooling and reheating from traditional cooling systems; and (2) avoids the increased fan energy and air heating from solid desiccant rotor systems.

  12. Desiccant-Based Preconditioning Market Analysis

    SciTech Connect

    Fischer, J.

    2001-01-11

    A number of important conclusions can be drawn as a result of this broad, first-phase market evaluation. The more important conclusions include the following: (1) A very significant market opportunity will exist for specialized outdoor air-handling units (SOAHUs) as more construction and renovation projects are designed to incorporate the recommendations made by the ASHRAE 62-1989 standard. Based on this investigation, the total potential market is currently $725,000,000 annually (see Table 6, Sect. 3). Based on the market evaluations completed, it is estimated that approximately $398,000,000 (55%) of this total market could be served by DBC systems if they were made cost-effective through mass production. Approximately $306,000,000 (42%) of the total can be served by a non-regenerated, desiccant-based total recovery approach, based on the information provided by this investigation. Approximately $92,000,000 (13%) can be served by a regenerated desiccant-based cooling approach (see Table 7, Sect. 3). (2) A projection of the market selling price of various desiccant-based SOAHU systems was prepared using prices provided by Trane for central-station, air-handling modules currently manufactured. The wheel-component pricing was added to these components by SEMCO. This resulted in projected pricing for these systems that is significantly less than that currently offered by custom suppliers (see Table 4, Sect. 2). Estimated payback periods for all SOAHU approaches were quite short when compared with conventional over-cooling and reheat systems. Actual paybacks may vary significantly depending on site-specific considerations. (3) In comparing cost vs benefit of each SOAHU approach, it is critical that the total system design be evaluated. For example, the cost premium of a DBC system is very significant when compared to a conventional air handling system, yet the reduced chiller, boiler, cooling tower, and other expense often equals or exceeds this premium, resulting in a

  13. Final draft: IEA Task 1. Report on Subtask D, optimization of solar heating and cooling systems

    SciTech Connect

    Freeman, T.L.

    1981-03-01

    A review of general techniques and specific methods useful in the optimization of solar heating and cooling systems is undertaken. A discussion of the state-of-the-art and the principal problems in both the simplified thermal performance analysis and economic analysis portions of the optimization problem are presented. Sample economic analyses are performed using several widely used economic criteria. The predicted thermal results of one typical, widely used simplified method is compared to detailed simulation results. A methodology for and the results of a sensitivity study of key economic parameters in the life cycle cost method are presented. Finally, a simple graphical optimization technique based on the life cycle cost method is proposed.

  14. Stability of cool flux tubes in the solar chromosphere. II - Non-linear dynamical behaviour

    NASA Astrophysics Data System (ADS)

    Hassan, S. S.; Kneer, F.

    1990-06-01

    A single vertical cool flux tube in the solar chromosphere is focused upon for stability studies. The analysis of a previous study by Hasan and Kneer (1986) is extended to the nonlinear regime with a view to examining the consequences of having self-exciting mechanisms of oscillations above the photosphere. In particular, the possibility of whether the motions driven by the convective instability caused by the presence of CO could extract sufficient energy from the radiation field near the Tmin region of empirical models and deposit it in higher layers to produce chromospheric heating is investigated. The time evolution of this instability is followed by solving the MHD equations in the thin flux tube approximation. The analysis includes energy exchange with the radiation field. The simulations of a flux tube with a transmitting upper boundary show that the average energy flux in the oscillations is inadequate for chromospheric heating.

  15. Final draft: IEA task 1. Report on subtask D, optimization of solar heating and cooling systems

    NASA Astrophysics Data System (ADS)

    Freeman, T. L.

    1981-03-01

    A review of general techniques and specific methods useful in the optimization of solar heating and cooling systems is undertaken. A discussion of the state of the art and the principal problems in both the simplified thermal performance analysis and economic analysis portions of the optimization problem are presented. Sample economic analyses are performed using several widely used economic criteria. The predicted thermal results of one typical, widely used simplified method is compared to detailed simulation results. A methodology for and the results of a sensitivity study of key economic parameters in the life cycle cost method are presented. Finally, a simple graphical optimization technique based on the life cycle cost method is proposed.

  16. Thermal storage studies for solar heating and cooling: Applications using chemical heat pumps

    NASA Astrophysics Data System (ADS)

    Offenhartz, P. O.

    1981-04-01

    The simulation of chemical heat pumps and simulations (including heating, cooling, and domestic hot water) were performed for Washington, D.C. and Ft. Worth, Texas. Direct weekly comparisons of the H2SO4/H2O and CaCl2/CH3OH cycles were carried out. Projected performance of the NH4NO3/NH3 cycle was also investigated, and was identical to H2SO4/H2O. In all simulated cases, the solar collector is a fixed evacuated tube system. With standard residential loads, the chemical heat pumps performed well. Gas fired backup via the heat pump was quite effective in reducing fossil fuel consumption. Chemical heat pumps are designed to reject heat at relatively high temperatures, however, they are also effective in providing domestic hot water.

  17. Incorporation of Solar Noble Gases from a Nebula-Derived Atmosphere During Magma Ocean Cooling

    NASA Technical Reports Server (NTRS)

    Woolum, D. S.; Cassen, P.; Wasserburg, G. J.; Porcelli, D.; DeVincenzi, Donald (Technical Monitor)

    1998-01-01

    The presence of solar noble gases in the deep interior of the Earth is inferred from the Ne isotopic compositions of MORB (Mid-ocean Ridge Basalts) and OIB (Oceanic Island Basalt); Ar data may also consistent with a solar component in the deep mantle. Models of the transport and distribution of noble gases in the earth's mantle allow for the presence of solar Ar/Ne and Xe/Ne ratios and permit the calculation of lower mantle noble gas concentrations. These mantle data and models also indicate that the Earth suffered early (0.7 to 2 x 10(exp 8) yr) and large (greater than 99 percent) losses of noble gases from the interior, a result previously concluded for atmospheric Xe. We have pursued the suggestion that solar noble gases were incorporated in the forming Earth from a massive, nebula-derived atmosphere which promoted large-scale melting, so that gases from this atmosphere dissolved in the magma ocean and were mixed downward. Models of a primitive atmosphere captured from the solar nebula and supported by accretion luminosity indicate that pressures at the Earth's surface were adequate (and largely more than the required 100 Atm) to dissolve sufficient gases. We have calculated the coupled evolution of the magma ocean and the overlying atmosphere under conditions corresponding to the cessation (or severe attenuation) of the sustaining accretion luminosity, prior to the complete removal of the solar nebula. Such a condition was likely to obtain, for instance, when most of the unaccumulated mass resided in large bodies which were only sporadically accreted. The luminosity supporting the atmosphere is then that provided by the cooling Earth, consideration of which sets a lower limit to the time required to solidify the mantle and terminate the incorporation of atmospheric gases within it. In our initial calculations, we have fixed the nebula temperature at To = 300K, a value likely to be appropriate for nebular temperatures at lAU in the early planet-building epoch

  18. Establish feasibility for providing passive cooling with solar updraft and evaporative downdraft chimneys. Final report, June 15, 1984--December 31, 1987

    SciTech Connect

    Cunningham, W.A.; Mignon, G.V.; Thompson, T.L.

    1987-12-31

    Natural draft towers can be used for cooling and ventilating structures. From an operational perspective, the downdraft evaporatively cooled tower is preferred for a dry climate. Solar chimneys, when used alone, tend to require an excessively large solar collector area when appreciable quantities of air must be moved. When used in combination with a downdraft tower, the roof and attic of buildings may assist the solar chimney and their use becomes more attractive. Both a frame building and a greenhouse were successfully cooled during this program. The economics of the downdraft tower compare favorably with conventional evaporative cooling for some application.

  19. DIRECT EVIDENCE FOR CONDENSATION IN THE EARLY SOLAR SYSTEM AND IMPLICATIONS FOR NEBULAR COOLING RATES

    SciTech Connect

    Berg, T.; Maul, J.; Schoenhense, G.; Marosits, E.; Hoppe, P.; Ott, U.; Palme, H.

    2009-09-10

    We have identified in an acid resistant residue of the carbonaceous chondrite Murchison a large number (458) of highly refractory metal nuggets (RMNs) that once were most likely hosted by Ca,Al-rich inclusions (CAIs). While osmium isotopic ratios of two randomly selected particles rule out a presolar origin, the bulk chemistry of 88 particles with sizes in the submicron range determined by energy dispersive X-ray (EDX) spectroscopy shows striking agreement with predictions of single-phase equilibrium condensation calculations. Both chemical composition and morphology strongly favor a condensation origin. Particularly important is the presence of structurally incompatible elements in particles with a single-crystal structure, which also suggests the absence of secondary alteration. The metal particles represent the most pristine early solar system material found so far and allow estimation of the cooling rate of the gaseous environment from which the first solids formed by condensation. The resulting value of 0.5 K yr{sup -1} is at least 4 orders of magnitude lower than the cooling rate of molten CAIs. It is thus possible, for the first time, to see through the complex structure of most CAIs and infer the thermal history of the gaseous reservoir from which their components formed by condensation.

  20. Decay-phase Cooling and Inferred Heating of M- and X-class Solar Flares

    NASA Astrophysics Data System (ADS)

    Ryan, Daniel; Chamberlin, Phillip C.; Milligan, Ryan O.; Gallagher, Peter T

    2014-06-01

    Hydrodynamic modelling is a well established and important field in understanding the evolution of solar flares. However, in order to be of greatest use the results of such models must be compared to statistically significant samples of flare observations. In this talk we observationally investigate the hydrodynamic decay phase evolution of 72 M- and X-class flares using GOES/XRS, SDO/EVE and Hinode/XRT and quantify their cooling rates. The results are then compared to the predictions of an analytical zero-dimensional hydrodynamic model. We find that the model does not fit the observations well, but does provide a well-defined lower limit on a flare's total cooling time. The discrepancy between observations and the model is then assumed to be primarily due to heating during the decay phase. The decay-phase heating necessary to account for the discrepancy is quantified and found be ~50% of the total thermally radiated energy, as calculated with GOES/XRS. This suggests that the energy released during the decay phase may be as significant as that released during the rise phase.

  1. Introduction to Solar Heating and Cooling Systems. D.O.T. 637.281 and .381. Student's Manual.

    ERIC Educational Resources Information Center

    Grimes, L. A., Jr.

    This manual on solar heating and cooling systems is one of a series of individualized instructional materials for students. The manual is self-paced, but is designed to be used under the supervision of a coordinator or an instructor. The manual contains 15 assignments, each with all the information needed, a list of objectives that should be met,…

  2. Introduction to Solar Heating and Cooling Systems. D.O.T. 637.281 and .381. Instructor's Guide.

    ERIC Educational Resources Information Center

    Grimes, L. A., Jr.

    This instructor's guide on solar heating and cooling is part of a series of individualized instructional materials. The guide is provided to help the instructor make certain that each student gets the most benefit possible from both the student's manual and what he/she does on the job. Notes for the instructor contain suggestions on how the…

  3. Design, evaluation and recommedation effort relating to the modification of a residential 3-ton absorption cycle cooling unit for operation with solar energy

    NASA Technical Reports Server (NTRS)

    Merrick, R. H.; Anderson, P. P.

    1973-01-01

    The possible use of solar energy powered absorption units to provide cooling and heating of residential buildings is studied. Both, the ammonia-water and the water-lithium bromide cycles, are considered. It is shown that the air cooled ammonia water unit does not meet the criteria for COP and pump power on the cooling cycle and the heat obtained from it acting as a heat pump is at too low a temperature. If the ammonia machine is water cooled it will meet the design criteria for cooling but can not supply the heating needs. The water cooled lithium bromide unit meets the specified performance for cooling with appreciably lower generator temperatures and without a mechanical solution pump. It is recommeded that in the demonstration project a direct expansion lithium bromide unit be used for cooling and an auxiliary duct coil using the solar heated water be employed for heating.

  4. Efficiently-cooled plasmonic amorphous silicon solar cells integrated with a nano-coated heat-pipe plate

    PubMed Central

    Zhang, Yinan; Du, Yanping; Shum, Clifford; Cai, Boyuan; Le, Nam Cao Hoai; Chen, Xi; Duck, Benjamin; Fell, Christopher; Zhu, Yonggang; Gu, Min

    2016-01-01

    Solar photovoltaics (PV) are emerging as a major alternative energy source. The cost of PV electricity depends on the efficiency of conversion of light to electricity. Despite of steady growth in the efficiency for several decades, little has been achieved to reduce the impact of real-world operating temperatures on this efficiency. Here we demonstrate a highly efficient cooling solution to the recently emerging high performance plasmonic solar cell technology by integrating an advanced nano-coated heat-pipe plate. This thermal cooling technology, efficient for both summer and winter time, demonstrates the heat transportation capability up to ten times higher than those of the metal plate and the conventional wickless heat-pipe plates. The reduction in temperature rise of the plasmonic solar cells operating under one sun condition can be as high as 46%, leading to an approximate 56% recovery in efficiency, which dramatically increases the energy yield of the plasmonic solar cells. This newly-developed, thermally-managed plasmonic solar cell device significantly extends the application scope of PV for highly efficient solar energy conversion. PMID:27113558

  5. Efficiently-cooled plasmonic amorphous silicon solar cells integrated with a nano-coated heat-pipe plate

    NASA Astrophysics Data System (ADS)

    Zhang, Yinan; Du, Yanping; Shum, Clifford; Cai, Boyuan; Le, Nam Cao Hoai; Chen, Xi; Duck, Benjamin; Fell, Christopher; Zhu, Yonggang; Gu, Min

    2016-04-01

    Solar photovoltaics (PV) are emerging as a major alternative energy source. The cost of PV electricity depends on the efficiency of conversion of light to electricity. Despite of steady growth in the efficiency for several decades, little has been achieved to reduce the impact of real-world operating temperatures on this efficiency. Here we demonstrate a highly efficient cooling solution to the recently emerging high performance plasmonic solar cell technology by integrating an advanced nano-coated heat-pipe plate. This thermal cooling technology, efficient for both summer and winter time, demonstrates the heat transportation capability up to ten times higher than those of the metal plate and the conventional wickless heat-pipe plates. The reduction in temperature rise of the plasmonic solar cells operating under one sun condition can be as high as 46%, leading to an approximate 56% recovery in efficiency, which dramatically increases the energy yield of the plasmonic solar cells. This newly-developed, thermally-managed plasmonic solar cell device significantly extends the application scope of PV for highly efficient solar energy conversion.

  6. Efficiently-cooled plasmonic amorphous silicon solar cells integrated with a nano-coated heat-pipe plate.

    PubMed

    Zhang, Yinan; Du, Yanping; Shum, Clifford; Cai, Boyuan; Le, Nam Cao Hoai; Chen, Xi; Duck, Benjamin; Fell, Christopher; Zhu, Yonggang; Gu, Min

    2016-04-26

    Solar photovoltaics (PV) are emerging as a major alternative energy source. The cost of PV electricity depends on the efficiency of conversion of light to electricity. Despite of steady growth in the efficiency for several decades, little has been achieved to reduce the impact of real-world operating temperatures on this efficiency. Here we demonstrate a highly efficient cooling solution to the recently emerging high performance plasmonic solar cell technology by integrating an advanced nano-coated heat-pipe plate. This thermal cooling technology, efficient for both summer and winter time, demonstrates the heat transportation capability up to ten times higher than those of the metal plate and the conventional wickless heat-pipe plates. The reduction in temperature rise of the plasmonic solar cells operating under one sun condition can be as high as 46%, leading to an approximate 56% recovery in efficiency, which dramatically increases the energy yield of the plasmonic solar cells. This newly-developed, thermally-managed plasmonic solar cell device significantly extends the application scope of PV for highly efficient solar energy conversion.

  7. Performance of evacuated tubular solar collectors in a residential heating and cooling system. Final report, 1 October 1978-30 September 1979

    SciTech Connect

    Duff, W.S.; Loef, G.O.G.

    1981-03-01

    Operation of CSU Solar House I during the heating season of 1978-1979 and during the 1979 cooling season was based on the use of systems comprising an experimental evacuated tubular solar collector, a non-freezing aqueous collection medium, heat exchange to an insulated conventional vertical cylindrical storage tank and to a built-up rectangular insulated storage tank, heating of circulating air by solar heated water and by electric auxiliary in an off-peak heat storage unit, space cooling by lithium bromide absorption chiller, and service water heating by solar exchange and electric auxiliary. Automatic system control and automatic data acquisition and computation are provided. This system is compared with others evaluated in CSU Solar Houses I, II and III, and with computer predictions based on mathematical models. Of the 69,513 MJ total energy requirement for space heating and hot water during a record cold winter, solar provided 33,281 MJ equivalent to 48 percent. Thirty percent of the incident solar energy was collected and 29 percent was delivered and used for heating and hot water. Of 33,320 MJ required for cooling and hot water during the summer, 79 percent or 26,202 MJ were supplied by solar. Thirty-five percent of the incident solar energy was collected and 26 percent was used for hot water and cooling in the summer. Although not as efficient as the Corning evacuated tube collector previously used, the Philips experimental collector provides solar heating and cooling with minimum operational problems. Improved performance, particularly for cooling, resulted from the use of a very well-insulated heat storage tank. Day time (on-peak) electric auxiliary heating was completely avoided by use of off-peak electric heat storage. A well-designed and operated solar heating and cooling system provided 56 percent of the total energy requirements for heating, cooling, and hot water.

  8. Radiative energy balance of Venus: An approach to parameterize thermal cooling and solar heating rates

    NASA Astrophysics Data System (ADS)

    Haus, R.; Kappel, D.; Arnold, G.

    2017-03-01

    Thermal cooling rates QC and solar heating rates QH in the atmosphere of Venus at altitudes between 0 and 100 km are investigated using the radiative transfer and radiative balance simulation techniques described by Haus et al. (2015b, 2016). QC strongly responds to temperature profile and cloud parameter changes, while QH is less sensitive to these parameters. The latter mainly depends on solar insolation conditions and the unknown UV absorber distribution. A parameterization approach is developed that permits a fast and reliable calculation of temperature change rates Q for different atmospheric model parameters and that can be applied in General Circulation Models to investigate atmospheric dynamics. A separation of temperature, cloud parameter, and unknown UV absorber influences is performed. The temperature response parameterization relies on a specific altitude and latitude-dependent cloud model. It is based on an algorithm that characterizes Q responses to a broad range of temperature perturbations at each level of the atmosphere using the Venus International Reference Atmosphere (VIRA) as basis temperature model. The cloud response parameterization considers different temperature conditions and a range of individual cloud mode factors that additionally change cloud optical depths as determined by the initial latitude-dependent model. A QH response parameterization for abundance changes of the unknown UV absorber is also included. Deviations between accurate calculation and parameterization results are in the order of a few tenths of K/day at altitudes below 90 km. The parameterization approach is used to investigate atmospheric radiative equilibrium (RE) conditions. Polar mesospheric RE temperatures above the cloud top are up to 70 K lower and equatorial temperatures up to 10 K higher than observed values. This radiative forcing field is balanced by dynamical processes that maintain the observed thermal structure.

  9. Effects of periodic desiccation on the synthesis of the UV-screening compound, scytonemin, in cyanobacteria.

    PubMed

    Fleming, Erich D; Castenholz, Richard W

    2007-06-01

    Scytonemin is an ultraviolet radiation (UVR)-screening compound synthesized by some sheathed cyanobacteria exposed to high solar and sky radiation. It is primarily produced in response to UVA radiation, but certain environmental stresses can enhance synthesis. This study focuses on the effects of periodic desiccation on scytonemin synthesis in three desiccation-tolerant cyanobacterial strains, Nostoc punctiforme PCC 73102, Chroococcidiopsis CCMEE 5056 and Chroococcidiopsis CCMEE 246. Nostoc punctiforme and Chroococcidiopsis CCMEE 5056 exposed to UVA radiation produced more concentrated scytonemin screens when experiencing periodic desiccation (i.e. 1 day desiccated for every 2 days hydrated) than when continuously hydrated. A more concentrated scytonemin screen would reduce the amount of UVR damage accrued when cells are desiccated and metabolically inactive. This might allow the cyanobacteria to allocate more energy to systems other than UVR damage repair during rehydration, which would facilitate recovery. The scytonemin screen is extremely stable, remaining largely intact in the sheaths of desiccated N. punctiforme even when continuously exposed to UVA radiation for about 2 months. In contrast to the above findings, scytonemin synthesis in Chroococcidiopsis CCMEE 246, a strain that produces scytonemin constitutively under low visible light (no UVA), was partially inhibited by periodic desiccation.

  10. Roof aperture system for selective collection and control of solar energy for building heating, cooling and daylighting

    DOEpatents

    Sanders, William J.; Snyder, Marvin K.; Harter, James W.

    1983-01-01

    The amount of building heating, cooling and daylighting is controlled by at least one pair of solar energy passing panels, with each panel of the pair of panels being exposed to a separate direction of sun incidence. A shutter-shade combination is associated with each pair of panels and the shutter is connected to the shade so that rectilinear movement of the shutter causes pivotal movement of the shade.

  11. Evaluation of residential and commercial solar/gas heating and cooling technologies. Volume 1: Program overview

    NASA Astrophysics Data System (ADS)

    Hirshberg, A. S.; Haas, S. A.; Jacobsen, A. S.

    1980-12-01

    The technologies and economics of solar/gas systems for application in the single-family residential market and in the small (individual building) commerical market were evaluated. The effects of solar industry maturity on system cost and the impact of solar incentives and natural gas price uncertainties on solar/gas system economics were studied. Projected solar/gas systems with advanced conventional gas equipment such as pulse combustion furnaces are discussed.

  12. Cool School.

    ERIC Educational Resources Information Center

    Stephens, Suzanne

    1980-01-01

    The design for Floyd Elementary School in Miami (Florida) seeks to harness solar energy to provide at least 70 percent of the annual energy for cooling needs and 90 percent for hot water. (Author/MLF)

  13. Instructor's Manual for Teaching and Practical Courses on Design of Systems and Sizing, Installation and Operation of Systems for Solar Heating and Cooling of Residential Buildings.

    ERIC Educational Resources Information Center

    Colorado State Univ., Ft. Collins. Solar Energy Applications Lab.

    Presented are guidelines for instructors of two courses in the design, installation, and operation of solar heating and cooling systems. These courses are: (1) Design of Systems, and (2) Sizing, Installation, and Operation of Systems. Limited in scope to active solar systems for residential buildings, these courses place primary emphasis upon…

  14. Solar Heating and Cooling of Buildings: Phase 0. Feasibility and Planning Study. Volume 1: Executive Summary. Document No. 74SD419. Final Report.

    ERIC Educational Resources Information Center

    General Electric Co., Philadelphia, PA. Space Div.

    The purpose of this study was to establish the technical and economic feasibility of using solar energy for the heating and cooling of buildings and to provide baseline information for the widespread application of solar energy. The initial step in this program was a study of the technical, economic, societal, legal, and environmental factors…

  15. Development and Implementation of Training Curriculum/Program in Solar Heating and Cooling at the Technician Level, December 1, 1976 - November 30, 1977. Final Report.

    ERIC Educational Resources Information Center

    Kuhnle, Carl J., Jr.

    The program proposal is designed to address the increasing demand for trained personnel to support the installation and maintenance of solar energy systems at residential and commercial sites. The three main objectives of the proposed program are: (1) to develop a flexible curricula to train a solar heating and cooling workforce; (2) to identify…

  16. Installation package for integrated programmable electronic controller and hydronic subsystem - solar heating and cooling

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A description is given of the Installation, Operation, and Maintenance Manual and information on the power panel and programmable microprocessor, a hydronic solar pump system and a hydronic heating hot water pumping system. These systems are integrated into various configurations for usages in solar energy management, control and monitoring, lighting control, data logging and other solar related applications.

  17. Active Desiccant Dehumidification Module Integration with Rooftop Packaged HVAC

    SciTech Connect

    Fischer, J

    2002-04-17

    This report summarizes a research and development program that produced a stand-alone active desiccant module (ADM) that can be easily integrated with new or existing packaged cooling equipment. The program also produced a fully integrated hybrid system, combining the active desiccant section with a conventional direct expansion air-conditioning unit, that resulted in a compact, low-cost, energy-efficient end product. Based upon the results of this investigation, both systems were determined to be highly viable products for commercialization. Major challenges--including wheel development, compact packaging, regeneration burner development, control optimization, and low-cost design--were all successfully addressed by the final prototypes produced and tested as part of this program. Extensive laboratory testing was completed in the SEMCO laboratory for each of the two ADM system approaches. This testing confirmed the performance of the ADM systems to be attractive compared with that of alternate approaches currently used to precondition outdoor air, where a return air path is not readily available for passive desiccant recovery or where first cost is the primary design criterion. Photographs, schematics, and performance maps are provided for the ADM systems that were developed; and many of the control advantages are discussed. Based upon the positive results of this research and development program, field tests are under way for fully instrumented pilot installations of ADM systems in both a hotel/motel and a restaurant.

  18. Gas Engine-Driven Heat Pump with Desiccant Dehumidification

    SciTech Connect

    Shen, Bo; Abu-Heiba, Ahmad

    2017-01-01

    About 40% of total U.S. energy consumption was consumed in residential and commercial buildings. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. This paper describes the development of an innovative natural gas, propane, LNG or bio-gas IC engine-driven heat pump (GHP) with desiccant dehumidification (GHP/DD). This integrated system has higher overall efficiencies than conventional equipment for space cooling, addresses both new and existing commercial buildings, and more effectively controls humidity in humid areas. Waste heat is recovered from the GHP to provide energy for regenerating the desiccant wheel and to augment heating capacity and efficiency. By combining the two technologies, an overall source COP of greater that 1.5 (hot, humid case) can be achieved by utilizing waste heat from the engine to reduce the overall energy required to regenerate the desiccant. Moreover, system modeling results show that the sensible heat ratio (SHR- sensible heat ratio) can be lowered to less 60% in a dedicated outdoor air system application with hot, humid cases.

  19. A comparison of fuel savings in the residential and commercial sectors generated by the installation of solar heating and cooling systems under three tax credit scenarios

    NASA Astrophysics Data System (ADS)

    Moden, R.

    An analysis of expected energy savings between 1977 and 1980 under three different solar tax credit scenarios is presented. The results were obtained through the solar heating and cooling of buildings (SHACOB) commercialization model. This simulation provides projected savings of conventional fuels through the installation of solar heating and cooling systems on buildings in the residential and commercial sectors. The three scenarios analyzed considered the tax credits contained in the Windfall Profits Tax of April 1980, the National Tax Act of November 1978, and a case where no tax credit is in effect.

  20. Market assessment for active solar heating and cooling products. Category B: a survey of decision-makers in the HVAC marketplace. Final report

    SciTech Connect

    1980-09-01

    A comprehensive evaluation of the market for solar heating and cooling products for new and retrofit markets is reported. The emphasis is on the analysis of solar knowledge among HVAC decision makers and a comprehensive evaluation of their solar attitudes and behavior. The data from each of the following sectors are described and analyzed: residential consumers, organizational and manufacturing buildings, HVAC engineers and architects, builders/developers, and commercial/institutional segments. (MHR)

  1. Spectroscopic study of a dark lane and a cool loop in a solar limb active region by Hinode/EIS

    SciTech Connect

    Lee, Kyoung-Sun; Imada, S.; Moon, Y.-J.; Lee, Jin-Yi

    2014-01-10

    We investigated a cool loop and a dark lane over a limb active region on 2007 March 14 using the Hinode/EUV Imaging Spectrometer. The cool loop is clearly seen in the spectral lines formed at the transition region temperature. The dark lane is characterized by an elongated faint structure in the coronal spectral lines and is rooted on a bright point. We examined their electron densities, Doppler velocities, and nonthermal velocities as a function of distance from the limb. We derived electron densities using the density sensitive line pairs of Mg VII, Si X, Fe XII, Fe XIII, and Fe XIV spectra. We also compared the observed density scale heights with the calculated scale heights from each peak formation temperatures of the spectral lines under the hydrostatic equilibrium. We noted that the observed density scale heights of the cool loop are consistent with the calculated heights, with the exception of one observed cooler temperature; we also found that the observed scale heights of the dark lane are much lower than their calculated scale heights. The nonthermal velocity in the cool loop slightly decreases along the loop, while nonthermal velocity in the dark lane sharply falls off with height. Such a decrease in the nonthermal velocity may be explained by wave damping near the solar surface or by turbulence due to magnetic reconnection near the bright point.

  2. Deriving precise parameters for cool solar-type stars. Optimizing the iron line list

    NASA Astrophysics Data System (ADS)

    Tsantaki, M.; Sousa, S. G.; Adibekyan, V. Zh.; Santos, N. C.; Mortier, A.; Israelian, G.

    2013-07-01

    Context. Temperature, surface gravity, and metallicitity are basic stellar atmospheric parameters necessary to characterize a star. There are several methods to derive these parameters and a comparison of their results often shows considerable discrepancies, even in the restricted group of solar-type FGK dwarfs. Aims: We want to check the differences in temperature between the standard spectroscopic technique based on iron lines and the infrared flux method (IRFM). We aim to improve the description of the spectroscopic temperatures especially for the cooler stars where the differences between the two methods are higher, as presented in a previous work. Methods: Our spectroscopic analysis was based on the iron excitation and ionization balance, assuming Kurucz model atmospheres in LTE. The abundance analysis was determined using the code MOOG. We optimized the line list using a cool star (HD 21749) with high resolution and high signal-to-noise spectrum, as a reference in order to check for weak, isolated lines. Results: We test the quality of the new line list by re-deriving stellar parameters for 451 stars with high resolution and signal-to-noise HARPS spectra, that were analyzed in a previous work with a larger line list. The comparison in temperatures between this work and the latest IRFM for the stars in common shows that the differences for the cooler stars are significantly smaller and more homogeneously distributed than in previous studies for stars with temperatures below 5000 K. Moreover, a comparison is presented between interferometric temperatures with our results that shows good agreement, even though the sample is small and the errors of the mean differences are large. We use the new line list to re-derive parameters for some of the cooler stars that host planets. Finally, we present the impact of the new temperatures on the [Cr i/Cr ii] and [Ti i/Ti ii] abundance ratios that previously showed systematic trends with temperature. We show that the slopes

  3. The Effects of Desiccation and Climatic Change on the Hydrology of the Aral Sea.

    NASA Astrophysics Data System (ADS)

    Small, Eric E.; Giorgi, Filippo; Cirbus Sloan, Lisa; Hostetler, Steven

    2001-02-01

    Anthropogenic desiccation of the Aral Sea between 1960 and the mid-1990s resulted in a substantial modification of the land surface that changed air temperature in the surrounding region. During the desiccation interval, the net annual rate of precipitation minus evaporation (P E) over the Aral Sea's surface became more negative by 15%, with the greatest changes occurring during the summer months. In addition, Aral Sea surface temperatures (SST) increased by up to 5°C in the spring and summer and decreased by up to 4°C in the fall and winter. A series of coupled regional climate-lake model experiments were completed to evaluate if the observed hydrologic changes are caused by desiccation or instead reflect larger-scale climatic variability or change, or some combination of both. If the P E changes are the result of desiccation, then a positive feedback exists that has amplified the anthropogenic perturbation to the hydrologic system.The effects of desiccation are examined by varying the simulated area, depth, and salinity of the Aral Sea in different model experiments. The simulated changes in SST resulting from desiccation are similar to the observed changes-both simulated and observed SSTs have increased during the spring and summer and have decreased during the fall and winter. The simulated changes in the annual cycle of P E resulting from desiccation are also similar to observed changes, but the simulated net annual decrease in P E is only 30% of the observed decrease. Warming has been observed across central Asia during the desiccation interval. The hydrologic response to this large-scale climatic variability or change was assessed by perturbing the meteorological boundary conditions (1.5°C cooling with constant relative humidity) but leaving the Aral Sea characteristics unchanged. The simulated effects of warming do not closely match the observed changes on the monthly timescale-SST changes are positive and the P E changes are negative in all months

  4. Coordination and management tasks for the IEA solar heating and cooling program and CCMS solar energy pilot study

    NASA Astrophysics Data System (ADS)

    Blum, S. B.; Kennish, W. J.

    1980-10-01

    Both the management assistance and technical involvement are discussed for a solar system performance validation effort. An overview of the program accomplishments is presented as well as conclusions for future work.

  5. Membrane-Based Absorption Refrigeration Systems: Nanoengineered Membrane-Based Absorption Cooling for Buildings Using Unconcentrated Solar & Waste Heat

    SciTech Connect

    2010-09-01

    BEETIT Project: UFL is improving a refrigeration system that uses low quality heat to provide the energy needed to drive cooling. This system, known as absorption refrigeration system (ARS), typically consists of large coils that transfer heat. Unfortunately, these large heat exchanger coils are responsible for bulkiness and high cost of ARS. UFL is using new materials as well as system design innovations to develop nanoengineered membranes to allow for enhanced heat exchange that reduces bulkiness. UFL’s design allows for compact, cheaper and more reliable use of ARS that use solar or waste heat.

  6. Program plan for reliability and maintainability in active solar heating and cooling systems

    NASA Astrophysics Data System (ADS)

    1980-10-01

    Specific objectives are as follows: provide all groups that have solar R & M concerns with the information that is available to the program and that can assist in alleviating those concerns; assist the solar energy industry in improving levels of R & M performance in state of the art solar energy systems, components, and materials; assist in the early development of a viable infrastructure for the design, manufacture, installation, and maintenance of reliable, maintainable, and durable solar energy systems; assist in the development of appropriate standards, code provisions, and certification programs relating to the R & M performance of solar energy systems, components, and materials; and develop the information required to support the other activities within the R & M program. These objectives correspond to five areas of action: regulations, research and development, technology transfer, solar industry infrastructure development, and data collection and analysis.

  7. Monitoring Vadose Zone Desiccation with Geophysical Methods

    SciTech Connect

    Truex, Michael J.; Johnson, Timothy C.; Strickland, Christopher E.; Peterson, John E.; Hubbard, Susan S.

    2013-05-01

    Soil desiccation was recently field tested as a potential vadose zone remediation technology. Desiccation removes water from the vadose zone and significantly decreases the aqueous-phase permeability of the desiccated zone, thereby decreasing movement of moisture and contaminants. The 2-D and 3-D distribution of moisture content reduction over time provides valuable information for desiccation operations and for determining when treatment goals have been reached. This type of information can be obtained through use of geophysical methods. Neutron moisture logging, cross-hole electrical resistivity tomography, and cross-hole ground penetrating radar approaches were evaluated with respect to their ability to provide effective spatial and temporal monitoring of desiccation during a treatability study conducted in the vadose zone of the DOE Hanford Site in WA.

  8. Energy and peak power saved by passively cooled residences

    NASA Astrophysics Data System (ADS)

    Clark, G.; Loxsom, F.; Doderer, E.; Vieira, R.; Fleischhacker, P.

    1983-11-01

    The energy displacement potential of roof pond cooling in humid climates is sensitive to the type of dehumidification equipment employed and the humidity levels allowed. The simulated energy requirements of roof pond residences assisted by two high efficiency dehumidifier options are described. One dehumidifier was a vapor compression air conditioner with sensible cooling recovery by an air-to-air heat exchanger (improved mechanical dehumidification or IMD). The second option was a solar regenerated desiccant dehumidifier (SRDD). An IMD assisted roof pond house had energy savings of 30 to 65% in humid climates compared to the conventional house; an SRDD assisted roof pond house had energy savings of 70 to 75% in humid climates.

  9. Solar-heated and cooled savings and loan building-1-Leavenworth, Kanasas

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Report describes heating and cooling system which furnishes 90 percent of annual heating load, 70 percent of cooling load, and all hot water for two-story building. Roof-mounted flat-plate collectors allow three distinct flow rates and are oriented south for optimum energy collection. Building contains fully automated temperature controls is divided into five temperature-load zones, each with independent heat pump.

  10. Solar heating, cooling, and domestic hot water system installed at Kaw Valley State Bank and Trust Company, Topeka, Kansas. Final report

    SciTech Connect

    1980-11-01

    The building has approximately 5600 square feet of conditioned space. Solar energy is used for space heating, space cooling, and preheating domestic hot water (DHW). The solar energy system has an array of evacuated tube-type collectors with an area of 1068 square feet. A 50/50 solution of ethylene glycol and water is the transfer medium that delivers solar energy to a tube-in-shell heat exchanger that in turn delivers solar-heated water to a 1100 gallon pressurized hot water storage tank. When solar energy is insufficient to satisfy the space heating and/or cooling demand, a natural gas-fired boiler provides auxiliary energy to the fan coil loops and/or the absorption chillers. Extracts from the site files, specification references, drawings, and installation, operation and maintenance instructions are included.

  11. Investigating the Effects of "Cool" Solar Reflective Pavements on California Climate

    NASA Astrophysics Data System (ADS)

    Mohegh, M.; Ban-Weiss, G. A.; Levinson, R.; Rosado, P.

    2015-12-01

    Implementing "Cool pavement" is a local mitigation strategy that can reduce urban heat islands. We investigated the climate impacts of widespread deployment of cool pavements by increasing the albedo of the pavements from 0.1 to 0.5 to understand the efficiency of cool pavements in reducing the temperature in California's urban areas. A validated parameterization of WRF model coupled with Single Layer Urban Canopy Model (SLUCM) is employed to simulate the effects of pavements at the bottom of canopy on urban heat islands. The results show local surface air temperature reductions, peaking at late morning and late evening which coincides with the lowest boundary layer height in the day time. Summer time temperature reductions up to 0.62 K in the evening (20:00 local) and 0.32 K in afternoon (14:00) in California are predicted. The cooling effects of 15 cities in California are sampled and analyzed. The average temperature reductions for the cities in California show 0.32 K temperature reduction per 0.1 total albedo reduction in the afternoon (14:00) which is consistent with the previous works. The linear relation between temperature reductions and the albedo increase is used to estimate the effect of cool pavements in "No Canopy" state, which can be used as an upper bound of the effects of cool pavements.

  12. Owens-Illinois subsystem design package for the SEC-601 air-cooled solar collector

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The subsystem design of the SEC-601 solar collector was evaluated. The collector is of modular design and is approximately 12 feet three inches wide and eight feet seven inches tall. It contains 72 collector tube elements and weighs approximately 300 pounds. Included in this report are the subsystem performance specifications and the assembly and installation drawings of the solar collectors and manifold.

  13. Evaluation of residential and commercial solar/gas heating and cooling technologies, volume 2

    NASA Astrophysics Data System (ADS)

    Hirshberg, A. S.; Haas, S. A.; Jacobsen, A. S.

    1980-12-01

    The economics of the most cost-effective solar/gas hybrid systems against a range of advanced gas-fired space conditioning equipment, including both conventional gas furnaces and pulse combustion gas furnaces were analyzed. In addition, the economic comparison considered improvements in performance and cost reduction for both solar/gas systems and advanced gas-fired equipment.

  14. Water isotopes in desiccating lichens

    PubMed Central

    Cuntz, Matthias; Máguas, Cristina; Lakatos, Michael

    2009-01-01

    The stable isotopic composition of water is routinely used as a tracer to study water exchange processes in vascular plants and ecosystems. To date, no study has focussed on isotope processes in non-vascular, poikilohydric organisms such as lichens and bryophytes. To understand basic isotope exchange processes of non-vascular plants, thallus water isotopic composition was studied in various green-algal lichens exposed to desiccation. The study indicates that lichens equilibrate with the isotopic composition of surrounding water vapour. A model was developed as a proof of concept that accounts for the specific water relations of these poikilohydric organisms. The approach incorporates first their variable thallus water potential and second a compartmentation of the thallus water into two isotopically distinct but connected water pools. Moreover, the results represent first steps towards the development of poikilohydric organisms as a recorder of ambient vapour isotopic composition. PMID:19888598

  15. Thermal and economic assessment of hot side sensible heat and cold side phase change storage combination fo absorption solar cooling system

    NASA Astrophysics Data System (ADS)

    Choi, M. K.; Morehouse, J. H.

    An analysis of a solar assisted absorption cooling system which employs a combination of phase change on the cold side and sensible heat storage on the hot side of the cooling machine for small commercial buildings is given. The year-round thermal performance of this system for space cooling were determined by simulation and compared against conventional cooling systems in three geographic locations: Phoenix, Arizona; Miami, Florida and Washington, D.C. The results indicate that the hot-cold storage combination has a considerable amount of energy and economical savings over hot side sensible heat storage. Using the hot-cold storage combination, the optimum collector areas for Washington, D.C., Phoenix and Miami are 355 m squared, 250 m squared and 495 m squared, respectively. Compared against conventional vapor compression chiller, the net solar fractions are 61, 67 and 69 percent, respectively.

  16. 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.

  17. Development of flat-plate solar collectors for the heating and cooling of buildings

    NASA Technical Reports Server (NTRS)

    Ramsey, J. W.; Borzoni, J. T.; Holland, T. H.

    1975-01-01

    The relevant design parameters in the fabrication of a solar collector for heating liquids were examined. The objective was to design, fabricate, and test a low-cost, flat-plate solar collector with high collection efficiency, high durability, and requiring little maintenance. Computer-aided math models of the heat transfer processes in the collector assisted in the design. The preferred physical design parameters were determined from a heat transfer standpoint and the absorber panel configuration, the surface treatment of the absorber panel, the type and thickness of insulation, and the number, spacing and material of the covers were defined. Variations of this configuration were identified, prototypes built, and performance tests performed using a solar simulator. Simulated operation of the baseline collector configuration was combined with insolation data for a number of locations and compared with a predicted load to determine the degree of solar utilization.

  18. [Desiccation cracking of soil body: a review].

    PubMed

    Pei, Yin-Ge; Xu, Ze-Min; Zhang, Jia-Ming

    2012-04-01

    Desiccation cracking of soil body is a complex physical process, which can affect the strength, stability, and permeability of soil body, and involve in several disciplines such as soil science, agricultural science, engineering geology, and environmental science. This paper introduced the significances of the study on the desiccation cracking of soil body, reviewed the related theoretical and applied researches and the quantitative analysis of crack morphology, and discussed the deficiencies in the research fields, research contents, and research methods. The future research directions about the desiccation cracking of soil body were pointed out.

  19. Development of flat-plate solar collectors for the heating and cooling of buildings: Executive summary

    NASA Technical Reports Server (NTRS)

    1978-01-01

    An efficient, low cost, flat-plate solar collector was developed. Computer aided mathematical models of the heat process in the collector were used in defining absorber panel configuration; determining insulation thickness; and in selecting the number, spacing, and material of the covers. Prototypes were built and performance tested. Data from simulated operation of the collector are compared with predicted loads from a number of locations to determine the degree of solar utilization.

  20. Cool heliosheath plasma and deceleration of the upstream solar wind at the termination shock.

    PubMed

    Richardson, John D; Kasper, Justin C; Wang, Chi; Belcher, John W; Lazarus, Alan J

    2008-07-03

    The solar wind blows outward from the Sun and forms a bubble of solar material in the interstellar medium. The termination shock occurs where the solar wind changes from being supersonic (with respect to the surrounding interstellar medium) to being subsonic. The shock was crossed by Voyager 1 at a heliocentric radius of 94 au (1 au is the Earth-Sun distance) in December 2004 (refs 1-3). The Voyager 2 plasma experiment observed a decrease in solar wind speed commencing on about 9 June 2007, which culminated in several crossings of the termination shock between 30 August and 1 September 2007 (refs 4-7). Since then, Voyager 2 has remained in the heliosheath, the region of shocked solar wind. Here we report observations of plasma at and near the termination shock and in the heliosheath. The heliosphere is asymmetric, pushed inward in the Voyager 2 direction relative to the Voyager 1 direction. The termination shock is a weak, quasi-perpendicular shock that heats the thermal plasma very little. An unexpected finding is that the flow is still supersonic with respect to the thermal ions downstream of the termination shock. Most of the solar wind energy is transferred to the pickup ions or other energetic particles both upstream of and at the termination shock.

  1. Comfortable, high-efficiency heat pump with desiccant-coated, water-sorbing heat exchangers

    PubMed Central

    Tu, Y. D.; Wang, R. Z.; Ge, T. S.; Zheng, X.

    2017-01-01

    Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8–3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed. Here, we report on a desiccant-enhanced, direct expansion heat pump based on a water-sorbing heat exchanger with a desiccant coating that exhibits an ultrahigh COP value of more than 7 without sacrificing any comfort or compactness. The pump’s efficiency is doubled compared to that of pumps currently used in conventional room air conditioners, which is a revolutionary HVAC breakthrough. Our proposed water-sorbing heat exchanger can independently handle sensible and latent loads at the same time. The desiccants adsorb moisture almost isothermally and can be regenerated by condensation heat. This new approach opens up the possibility of achieving ultrahigh efficiency for a broad range of temperature- and humidity-control applications. PMID:28079171

  2. Comfortable, high-efficiency heat pump with desiccant-coated, water-sorbing heat exchangers.

    PubMed

    Tu, Y D; Wang, R Z; Ge, T S; Zheng, X

    2017-01-12

    Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8-3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed. Here, we report on a desiccant-enhanced, direct expansion heat pump based on a water-sorbing heat exchanger with a desiccant coating that exhibits an ultrahigh COP value of more than 7 without sacrificing any comfort or compactness. The pump's efficiency is doubled compared to that of pumps currently used in conventional room air conditioners, which is a revolutionary HVAC breakthrough. Our proposed water-sorbing heat exchanger can independently handle sensible and latent loads at the same time. The desiccants adsorb moisture almost isothermally and can be regenerated by condensation heat. This new approach opens up the possibility of achieving ultrahigh efficiency for a broad range of temperature- and humidity-control applications.

  3. Comfortable, high-efficiency heat pump with desiccant-coated, water-sorbing heat exchangers

    NASA Astrophysics Data System (ADS)

    Tu, Y. D.; Wang, R. Z.; Ge, T. S.; Zheng, X.

    2017-01-01

    Comfortable, efficient, and affordable heating, ventilation, and air conditioning systems in buildings are highly desirable due to the demands of energy efficiency and environmental friendliness. Traditional vapor-compression air conditioners exhibit a lower coefficient of performance (COP) (typically 2.8–3.8) owing to the cooling-based dehumidification methods that handle both sensible and latent loads together. Temperature- and humidity-independent control or desiccant systems have been proposed to overcome these challenges; however, the COP of current desiccant systems is quite small and additional heat sources are usually needed. Here, we report on a desiccant-enhanced, direct expansion heat pump based on a water-sorbing heat exchanger with a desiccant coating that exhibits an ultrahigh COP value of more than 7 without sacrificing any comfort or compactness. The pump’s efficiency is doubled compared to that of pumps currently used in conventional room air conditioners, which is a revolutionary HVAC breakthrough. Our proposed water-sorbing heat exchanger can independently handle sensible and latent loads at the same time. The desiccants adsorb moisture almost isothermally and can be regenerated by condensation heat. This new approach opens up the possibility of achieving ultrahigh efficiency for a broad range of temperature- and humidity-control applications.

  4. Comparison of solar heat pump systems to conventional methods for residential heating, cooling, and water heating, volume 2

    NASA Astrophysics Data System (ADS)

    Hughes, P. J.; Morehouse, J. H.

    1980-04-01

    The series and parallel combined solar heat pump systems investigated are at best marginally competitive, on a 20 year life cycle cost basis, with conventional oil and electric furnace systems. The combined solar heat pump systems are not economically competitive with conventional gas furnace or stand alone heat pump systems for residential space heating, cooling and water heating. The combined solar heat pump systems do offer the potential for significant energy savings as compared to conventional furnace systems and the stand alone heat pump. The cost of that savings, however, is beyond that which the average consumer can be expected to pay. Barring unforeseen manufacturing process or materials breakthroughs, parallel systems prices are firm. The prices listed for series systems already include low cost site built collectors and an optimistic estimate of the liquid to air heat pump costs, and prices on other series system components are firm. A collector cost sensitivity analysis did not offer any encouraging directions towards significant systems cost reduction.

  5. Decay-phase cooling and inferred heating of M- and X-class solar flares

    SciTech Connect

    Ryan, Daniel F.; Gallagher, Peter T.; Chamberlin, Phillip C.; Milligan, Ryan O.

    2013-11-20

    In this paper, the cooling of 72 M- and X-class flares is examined using GOES/XRS and SDO/EVE. The observed cooling rates are quantified and the observed total cooling times are compared with the predictions of an analytical zero-dimensional hydrodynamic model. We find that the model does not fit the observations well, but does provide a well-defined lower limit on a flare's total cooling time. The discrepancy between observations and the model is then assumed to be primarily due to heating during the decay phase. The decay-phase heating necessary to account for the discrepancy is quantified and found be ∼50% of the total thermally radiated energy, as calculated with GOES. This decay-phase heating is found to scale with the observed peak thermal energy. It is predicted that approximating the total thermal energy from the peak is minimally affected by the decay-phase heating in small flares. However, in the most energetic flares the decay-phase heating inferred from the model can be several times greater than the peak thermal energy.

  6. Direct contact liquid-liquid heat exchanger for solar heated and cooled buildings. Final report, January 1, 1979-May 30, 1980

    SciTech Connect

    Karaki, S.; Brothers, P.

    1980-06-01

    The technical and economic feasibility of using a direct contact liquid-liquid heat exchanger (DCLLHE) storage unit in a solar heating and cooling system is established. Experimental performance data were obtained from the CSU Solar House I using a DCLLHE for both heating and cooling functions. A simulation model for the system was developed. The model was validated using the experimental data and applied in five different climatic regions of the country for a complete year. The life-cycle cost of the system was estimated for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger. It is concluded that while thare is a performance advantage with a DCLLHE system over a conventional solar system, the advantage is not sufficiently large to overcome slightly higher capital and operating costs for the DCLLHE system.

  7. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume III. Appendices

    SciTech Connect

    1980-01-01

    The overall, long term objective of the Solar Central Receiver Hybrid Power System is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumpton, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains appendices to the conceptual design and systems analysis studies gien in Volume II, Books 1 and 2. (WHK)

  8. Solute Leakage Resulting from Leaf Desiccation

    PubMed Central

    Leopold, A. Carl; Musgrave, Mary E.; Williams, Kathleen M.

    1981-01-01

    The leakage of solutes from foliar tissue is utilized as a dynamic measure of apparent changes in membrane integrity in response to desiccation. It is found that rehydrating leaf discs of cowpea (Vigna sinensis [L.] Endl.) show increasing leakiness in proportion to the extent of prior desiccation, whereas Selaginella lepidophylla Spring., a resurrection plant, does not. The elevated leakage rate of cowpea after desiccation recovers with time, and the passage of time in the stressed condition results in reduced subsequent leakiness. These characteristics are interpreted as suggesting that the leakage of solute reflects the condition of cellular membranes, and that desiccation stress leads to lesions in the membranes. The kinetics of solute leakage is suggested as a simple means of following changes in membrane lesions and associated features of membrane repair and hardening. PMID:16662082

  9. Direct contact liquid-liquid heat exchanger for solar-heated and -cooled buildings. Final report, January 1, 1979-May 30, 1980

    SciTech Connect

    Karaki, S.; Brothers, P.

    1980-06-01

    The procedure used was to obtain experimental performance data from a solar system using a DCLLHE for both heating and cooling functions, develop a simulation model for the system, validate the model using the data, apply the model in five different climatic regions of the country for a complete year, and estimate the life-cycle cost of the system for each application. The results are compared to a conventional solar system, using a standard shell-and-tube heat exchanger.

  10. Surface roughness effects on the solar reflectance of cool asphalt shingles

    SciTech Connect

    Akbari, Hashem; Berdahl, Paul; Akbari, Hashem; Jacobs, Jeffry; Klink, Frank

    2008-02-17

    We analyze the solar reflectance of asphalt roofing shingles that are covered with pigmented mineral roofing granules. The reflecting surface is rough, with a total area approximately twice the nominal area. We introduce a simple analytical model that relates the 'micro-reflectance' of a small surface region to the 'macro-reflectance' of the shingle. This model uses a mean field approximation to account for multiple scattering effects. The model is then used to compute the reflectance of shingles with a mixture of different colored granules, when the reflectances of the corresponding mono-color shingles are known. Simple linear averaging works well, with small corrections to linear averaging derived for highly reflective materials. Reflective base granules and reflective surface coatings aid achievement of high solar reflectance. Other factors that influence the solar reflectance are the size distribution of the granules, coverage of the asphalt substrate, and orientation of the granules as affected by rollers during fabrication.

  11. Passive solar/Earth sheltered office/dormitory cooling season thermal performance

    NASA Astrophysics Data System (ADS)

    Christian, J.

    1984-06-01

    Continuous detailed hourly thermal performance measurements were taken since February 1982 in and around an occupied, underground, 4000 ft(2) office/dormitory building at the Oak Ridge National Laboratory in Oak Ridge, Tennessee. This building has a number of energy saving features which were analyzed relative to their performance in a southeastern US climate and with respect to overall commercial building performance. Cooling season performance is documented, as well as effects of earth constact, interior thermal mass, an economizer cycle and interface of an efficient building envelope with a central three-ton heat pump. The Joint Institute Dormitory obtains a cooling energy savings of about 30% compared with an energy-efficient, above-grade structure and has the potential to save as much as 50%. The proper instllation of the overhand, interior thermal mass, massive supply duct system, and earth contact team up to prevent summertime overheating. From May through September, this building cost a total of $300 (at 5.7) cents/kWh) to cool and ventilate 24 hours per day. Besides thermal performance of the building envelope, extensive comfort data was taken illustrating that at least 90% of the occupants are comfortable all of the time according to the PMV measurements.

  12. Performance simulation of the JPL solar-powered distiller. Part 1: Quasi-steady-state conditions. [for cooling microwave equipment

    NASA Technical Reports Server (NTRS)

    Yung, C. S.; Lansing, F. L.

    1983-01-01

    A 37.85 cu m (10,000 gallons) per year (nominal) passive solar powered water distillation system was installed and is operational in the Venus Deep Space Station. The system replaced an old, electrically powered water distiller. The distilled water produced with its high electrical resistivity is used to cool the sensitive microwave equipment. A detailed thermal model was developed to simulate the performance of the distiller and study its sensitivity under varying environment and load conditions. The quasi-steady state portion of the model is presented together with the formulas for heat and mass transfer coefficients used. Initial results indicated that a daily water evaporation efficiency of 30% can be achieved. A comparison made between a full day performance simulation and the actual field measurements gave good agreement between theory and experiment, which verified the model.

  13. The cool component and the dichotomy, lateral expansion, and axial rotation of solar X-ray jets

    SciTech Connect

    Moore, Ronald L.; Sterling, Alphonse C.; Falconer, David A.; Robe, Dominic

    2013-06-01

    We present results from a study of 54 polar X-ray jets that were observed in coronal X-ray movies from the X-ray Telescope on Hinode and had simultaneous coverage in movies of the cooler transition region (T ∼ 10{sup 5} K) taken in the He II 304 Å band of the Atmospheric Imaging Assembly (AIA) on Solar Dynamics Observatory. These dual observations verify the standard-jet/blowout-jet dichotomy of polar X-ray jets previously found primarily from XRT movies alone. In accord with models of blowout jets and standard jets, the AIA 304 Å movies show a cool (T ∼ 10{sup 5} K) component in nearly all blowout X-ray jets and in a small minority of standard X-ray jets, obvious lateral expansion in blowout X-ray jets but none in standard X-ray jets, and obvious axial rotation in both blowout X-ray jets and standard X-ray jets. In our sample, the number of turns of axial rotation in the cool-component standard X-ray jets is typical of that in the blowout X-ray jets, suggesting that the closed bipolar magnetic field in the jet base has substantial twist not only in all blowout X-ray jets but also in many standard X-ray jets. We point out that our results for the dichotomy, lateral expansion, and axial rotation of X-ray jets add credence to published speculation that type-II spicules are miniature analogs of X-ray jets, are generated by granule-size emerging bipoles, and thereby carry enough energy to power the corona and solar wind.

  14. To develop a dynamic model of a collector loop for purpose of improved control of solar heating and cooling. Final technical report. [TRNSYS code

    SciTech Connect

    Herczfeld, P R; Fischl, R

    1980-01-01

    The program objectives were to (1) assess the feasibility of using the TRNSYS computer code for solar heating and cooling control studies and modify it wherever possible, and (2) develop a new dynamic model of the solar collector which reflects the performance of the collector under transient conditions. Also, the sensitivity of the performance of this model to the various system parameters such as collector time constants, flow rates, turn-on and turn-off temperature set points, solar insolation, etc., was studied. Results are presented and discussed. (WHK)

  15. Colorado State University program for developing, testing, evaluating and optimizing solar heating and cooling systems: Project status report for the months of October and November, 1994

    SciTech Connect

    Not Available

    1994-12-01

    This report describes a project to develop tools for evaluating solar heating and cooling systems. Current work on this project has been to validate the Florida Solar Energy Center`s (FSEC) models of the Solahart 302K and 302K-AS systems to prepare a rating for the Sacramento Municipal Utility District`s rebate program for solar domestic hot water heaters. A preliminary rating has been issued by FSEC and updated ratings will be released as necessary. Two of the problems that were mentioned in the August/September report are addressed and a tank heat loss test is discussed. Work continues on improving and validating the models.

  16. Tardigrades Use Intrinsically Disordered Proteins to Survive Desiccation.

    PubMed

    Boothby, Thomas C; Tapia, Hugo; Brozena, Alexandra H; Piszkiewicz, Samantha; Smith, Austin E; Giovannini, Ilaria; Rebecchi, Lorena; Pielak, Gary J; Koshland, Doug; Goldstein, Bob

    2017-03-16

    Tardigrades are microscopic animals that survive a remarkable array of stresses, including desiccation. How tardigrades survive desiccation has remained a mystery for more than 250 years. Trehalose, a disaccharide essential for several organisms to survive drying, is detected at low levels or not at all in some tardigrade species, indicating that tardigrades possess potentially novel mechanisms for surviving desiccation. Here we show that tardigrade-specific intrinsically disordered proteins (TDPs) are essential for desiccation tolerance. TDP genes are constitutively expressed at high levels or induced during desiccation in multiple tardigrade species. TDPs are required for tardigrade desiccation tolerance, and these genes are sufficient to increase desiccation tolerance when expressed in heterologous systems. TDPs form non-crystalline amorphous solids (vitrify) upon desiccation, and this vitrified state mirrors their protective capabilities. Our study identifies TDPs as functional mediators of tardigrade desiccation tolerance, expanding our knowledge of the roles and diversity of disordered proteins involved in stress tolerance.

  17. Market assessment for active solar heating and cooling products. Category B: A survey of decision makers in the HVAC market place. Survey instruments

    SciTech Connect

    Lilien, G. L.; Johnston, P. E.

    1980-09-01

    Telephone screener questionnaires and mail-out questionnaires for marketing surveys for solar heating and cooling equipment are presented. Questionnaires are included for the residential segment, industrial segment, HVAC professionals segment, builder/developer segment, and the commercial segment. No results are reported. (WHK)

  18. Desiccation tolerance in Bryophytes: relevance to the evolution of desiccation tolerance in Land Plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The majority of desiccation-tolerant plants are found in the less complex clades that constitute the algae, lichens and bryophytes. However, within the larger and more complex groups of vascular land plants there are some 120-130 species that exhibit some degree of vegetative desiccation tolerance. ...

  19. Parametric study of rock pile thermal storage for solar heating and cooling phase 1

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1977-01-01

    The test data and an analysis were presented, of heat transfer characteristics of a solar thermal energy storage bed utilizing water filled cans as the energy storage medium. An attempt was made to optimize can size, can arrangement, and bed flow rates by experimental and analytical means. Liquid filled cans, as storage media, utilize benefits of both solids like rocks, and liquids like water. It was found that this combination of solid and liquid media shows unique heat transfer and heat content characteristics and is well suited for use with solar air systems for space and hot water heating. An extensive parametric study was made of heat transfer characteristics of rocks, of other solids, and of solid containers filled with liquids.

  20. Validation of the solar heating and cooling high speed performance (HISPER) computer code

    NASA Technical Reports Server (NTRS)

    Wallace, D. B.

    1980-01-01

    Developed to give a quick and accurate predictions HISPER, a simplification of the TRNSYS program, achieves its computational speed by not simulating detailed system operations or performing detailed load computations. In order to validate the HISPER computer for air systems the simulation was compared to the actual performance of an operational test site. Solar insolation, ambient temperature, water usage rate, and water main temperatures from the data tapes for an office building in Huntsville, Alabama were used as input. The HISPER program was found to predict the heating loads and solar fraction of the loads with errors of less than ten percent. Good correlation was found on both a seasonal basis and a monthly basis. Several parameters (such as infiltration rate and the outside ambient temperature above which heating is not required) were found to require careful selection for accurate simulation.

  1. Transcriptomic analysis of Salmonella desiccation resistance.

    PubMed

    Li, Haiping; Bhaskara, Anuhya; Megalis, Christina; Tortorello, Mary Lou

    2012-12-01

    The survival of Salmonella in low moisture foods and processing environments remains a great challenge for the food industry and public health. To explore the mechanisms of Salmonella desiccation resistance, we studied the transcriptomic responses in Salmonella Tennessee (Tennessee), using Salmonella Typhimurium LT2 (LT2), a strain weakly resistant to desiccation, as a reference strain. In response to 2 h of air-drying at 11% equilibrated relative humidity, approximately one-fourth of the open reading frames (ORFs) in the Tennessee genome and one-fifth in LT2 were differentially expressed (>2-fold). Among all differentially expressed functional groups (>5-fold) in both strains, the expression fold change associated with fatty acid metabolism was the highest, and constituted 51% and 35% of the total expression fold change in Tennessee and LT2, respectively. Tennessee showed greater changes in expression of genes associated with stress response and envelope modification than LT2, while showing lesser changes in protein biosynthesis expression. Expression of flagella genes was significantly more inhibited in stationary phase cells of Tennessee than LT2 both before and after desiccation. The accumulation of the osmolyte trehalose was significantly induced by desiccation in Tennessee, but no increase was detectable in LT2, which is consistent with the expression patterns of the entire trehalose biosynthesis and degradation pathways in both strains. Results from this study present a global view of the dynamic desiccation responses in Salmonella, which will guide future research efforts to control Salmonella in low moisture environments.

  2. Proof-of-Concept Testing of the Passive Cooling System (T-CLIP™) for Solar Thermal Applications at an Elevated Temperature

    SciTech Connect

    Kim, Seung Jun; Quintana, Donald L.; Vigil, Gabrielle M.; Perraglio, Martin Juan; Farley, Cory Wayne; Tafoya, Jose I.; Martinez, Adam L.

    2015-11-30

    The Applied Engineering and Technology-1 group (AET-1) at Los Alamos National Laboratory (LANL) conducted the proof-of-concept tests of SolarSPOT LLC’s solar thermal Temperature- Clipper, or T-CLIP™ under controlled thermal conditions using a thermal conditioning unit (TCU) and a custom made environmental chamber. The passive T-CLIP™ is a plumbing apparatus that attaches to a solar thermal collector to limit working fluid temperature and to prevent overheating, since overheating may lead to various accident scenarios. The goal of the current research was to evaluate the ability of the T-CLIP™ to control the working fluid temperature by using its passive cooling mechanism (i.e. thermosiphon, or natural circulation) in a small-scale solar thermal system. The assembled environmental chamber that is thermally controlled with the TCU allows one to simulate the various possible weather conditions, which the solar system will encounter. The performance of the T-CLIP™ was tested at two different target temperatures: 1) room temperature (70 °F) and 2) an elevated temperature (130 °F). The current test campaign demonstrated that the T-CLIP™ was able to prevent overheating by thermosiphon induced cooling in a small-scale solar thermal system. This is an important safety feature in situations where the pump is turned off due to malfunction or power outages.

  3. Sun Heats, Cools Columbus Tech.

    ERIC Educational Resources Information Center

    American School and University, 1980

    1980-01-01

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

  4. Large-Scale Coronal Heating from "Cool" Activity in the Solar Magnetic Network

    NASA Technical Reports Server (NTRS)

    Falconer, D. A.; Moore, R. L.; Porter, J. G.; Hathaway, D. H.

    1999-01-01

    In Fe XII images from SOHO/EIT, the quiet solar corona shows structure on scales ranging from sub-supergranular (i.e., bright points and coronal network) to multi-supergranular (large-scale corona). In Falconer et al 1998 (Ap.J., 501, 386) we suppressed the large-scale background and found that the network-scale features are predominantly rooted in the magnetic network lanes at the boundaries of the supergranules. Taken together, the coronal network emission and bright point emission are only about 5% of the entire quiet solar coronal Fe XII emission. Here we investigate the relationship between the large-scale corona and the network as seen in three different EIT filters (He II, Fe IX-X, and Fe XII). Using the median-brightness contour, we divide the large-scale Fe XII corona into dim and bright halves, and find that the bright-half/dim half brightness ratio is about 1.5. We also find that the bright half relative to the dim half has 10 times greater total bright point Fe XII emission, 3 times greater Fe XII network emission, 2 times greater Fe IX-X network emission, 1.3 times greater He II network emission, and has 1.5 times more magnetic flux. Also, the cooler network (He II) radiates an order of magnitude more energy than the hotter coronal network (Fe IX-X, and Fe XII). From these results we infer that: 1) The heating of the network and the heating of the large-scale corona each increase roughly linearly with the underlying magnetic flux. 2) The production of network coronal bright points and heating of the coronal network each increase nonlinearly with the magnetic flux. 3) The heating of the large-scale corona is driven by widespread cooler network activity rather than by the exceptional network activity that produces the network coronal bright points and the coronal network. 4) The large-scale corona is heated by a nonthermal process since the driver of its heating is cooler than it is. This work was funded by the Solar Physics Branch of NASA's office of

  5. Successive dehumidification/regeneration cycles by LiCL desiccant for air-conditioning system

    NASA Astrophysics Data System (ADS)

    Bouzenada, S.; Kaabi, A. N.; Fraikin, L.; Léonard, A.

    2017-02-01

    Dehumidification by desiccant is a new application in air-conditioning system. This technology is providing important advantages in solving many problems and brings environmentally friendly products. Desiccants are natural substances that are capable of showing a strong attraction for water vapour and can be regenerated. They can undergo continuous cycles. An experimental study is carried out on successive phases of absorption/regeneration, during 7 days by using LiCl desiccant and on separate phases. The effect of climatic parameters on moisture removal rate and salt concentration on absorption and regeneration processes is discussed. The results show that higher air humidity gives a higher mass transfer potential then a higher moisture rate absorbed dm/dt. The decrease of salt concentration affects the dm/dt and vapour pressure. Also, these results show that at regeneration temperature, the amount of water desorbed is nearly equal to the amount of water absorbed (equilibrium condition) for a complete cycle. The amount of 7.87 mg of water vapor can be absorbed in the first hour of absorption cycle for 12.6144 mg at 50% of relative humidity, and 7.004mg for 36.31 mg of initial mass subjected at 70% RH. The LiCl desiccant is able to return to almost its original concentration 31.39% during regeneration phase. Also, LiCl desiccant is able to be regenerated at low temperature 40°C which can be easily obtained by using solar energy. Then, the LiCl is a good hygroscopic material for using in liquid desiccant air-conditioning system.

  6. Performance evaluation of a solar ejector-vapour compression cycle for cooling application

    NASA Astrophysics Data System (ADS)

    Megdouli, K.; Elakhdar, M.; Nahdi, E.; Kairouani, L.; Mhimid, A.

    2015-04-01

    This study deals with the performance of the ejector-vapour compression cycle assisted by solar. The effect of operating conditions on the combined cycle performance is examined. Also, a comparison of the system performance with environment friendly refrigerants (R134a, R600, R123, R141b, R142b, R152a, R290, and R245fa) is made. This performance is calculated using an empirical correlation. Thermodynamic properties of functioning fluids are obtained with package REFPROP 8. Using the typical meteorological year file containing the weather data of the city of Tunis, the system performance is computed for three collector types. The theoretical results show that the R290 offers the highest coefficient of performance, COP=3.75, for generator temperature TB = 78°C, condenser temperature Tc = 30°C and the intercooler temperature Te = 15°C.

  7. Vapor pressures of the aqueous desiccants

    SciTech Connect

    Chung, T.W.; Luo, C.M.

    1999-09-01

    The vapor pressures of the aqueous desiccants lithium chloride, lithium bromide, calcium chloride, ethylene glycol, propylene glycol, and their mixtures were measured at their typical operating concentrations and at temperatures from 298 K to 313 K. The experimental data were fitted to an Antoine type of equation, ln[P(kPa)] = A {minus} B/[T(K) + C], where A, B, and C are constants and are concentration dependent. Vapor pressure data were further used to predict the effectiveness of dehumidification in liquid desiccant dehumidifiers.

  8. From Anti-greenhouse Effect of Solar Absorbers to Cooling Effect of Greenhouse Gases: A 1-D Radiative Convective Model Study

    NASA Astrophysics Data System (ADS)

    Shia, R.

    2012-12-01

    The haze layer in Titan's upper atmosphere absorbs 90% of the solar radiation, but is inefficient for trapping infrared radiation generated by the surface. Its existence partially compensates for the greenhouse warming and keeps the surface approximately 9°C cooler than would otherwise be expected from the greenhouse effect alone. This is the so called anti-greenhouse effect (McKay et al., 1991). This effect can be used to alleviate the warming caused by the increasing level of greenhouse gases in the Earth's atmosphere. A one-dimensional radiative convective model (Kasting et al., 2009 and references listed there) is used to investigate the anti-greenhouse effect in the Earth atmosphere. Increasing of solar absorbers, e.g. aerosols and ozone, in the stratosphere reduces the surface solar flux and cool the surface. However, the absorption of the solar flux also increases the temperature in the upper atmosphere, while reduces the temperature at the surface. Thus, the temperature profile of the atmosphere changes and the regions with positive vertical temperature gradient are expanded. According to Shia (2010) the radiative forcing of greenhouse gases is directly related to the vertical temperature gradient. Under the new temperature profile increases of greenhouse gases should have less warming effect. When the solar absorbers keep increasing, eventually most of the atmosphere has positive temperature gradient and increasing greenhouse gases would cool the surface (Shia, 2011). The doubling CO2 scenario in the Earth atmosphere is simulated for different levels of solar absorbers using the 1-D RC model. The model results show that if the solar absorber increases to a certain level that less than 50% solar flux reaching the surface, doubling CO2 cools the surface by about 2 C. This means if the snowball Earth is generated by solar absorbers in the stratosphere, increasing greenhouse gases would make it freeze even more (Shia, 2011). References: Kasting, J. et al

  9. Experimental performance study of a proposed desiccant based air conditioning system.

    PubMed

    Bassuoni, M M

    2014-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system.

  10. Experimental performance study of a proposed desiccant based air conditioning system

    PubMed Central

    Bassuoni, M.M.

    2013-01-01

    An experimental investigation on the performance of a proposed hybrid desiccant based air conditioning system referred as HDBAC is introduced in this paper. HDBAC is mainly consisted of a liquid desiccant dehumidification unit integrated with a vapor compression system (VCS). The VCS unit has a cooling capacity of 5.27 kW and uses 134a as refrigerant. Calcium chloride (CaCl2) solution is used as the working desiccant material. HDBAC system is used to serve low sensible heat factor applications. The effect of different parameters such as, process air flow rate, desiccant solution flow rate, evaporator box and condenser box solution temperatures, strong solution concentration and regeneration temperature on the performance of the system is studied. The performance of the system is evaluated using some parameters such as: the coefficient of performance (COPa), specific moisture removal and energy saving percentage. A remarkable increase of about 54% in the coefficient of performance of the proposed system over VCS with reheat is achieved. A maximum overall energy saving of about 46% is observed which emphasizes the use of the proposed system as an energy efficient air conditioning system. PMID:25685475

  11. C4 grasses prosper as carbon dioxide eliminates desiccation in warmed semi-arid grassland.

    PubMed

    Morgan, Jack A; LeCain, Daniel R; Pendall, Elise; Blumenthal, Dana M; Kimball, Bruce A; Carrillo, Yolima; Williams, David G; Heisler-White, Jana; Dijkstra, Feike A; West, Mark

    2011-08-03

    Global warming is predicted to induce desiccation in many world regions through increases in evaporative demand. Rising CO(2) may counter that trend by improving plant water-use efficiency. However, it is not clear how important this CO(2)-enhanced water use efficiency might be in offsetting warming-induced desiccation because higher CO(2) also leads to higher plant biomass, and therefore greater transpirational surface. Furthermore, although warming is predicted to favour warm-season, C(4) grasses, rising CO(2) should favour C(3), or cool-season plants. Here we show in a semi-arid grassland that elevated CO(2) can completely reverse the desiccating effects of moderate warming. Although enrichment of air to 600 p.p.m.v. CO(2) increased soil water content (SWC), 1.5/3.0 °C day/night warming resulted in desiccation, such that combined CO(2) enrichment and warming had no effect on SWC relative to control plots. As predicted, elevated CO(2) favoured C(3) grasses and enhanced stand productivity, whereas warming favoured C(4) grasses. Combined warming and CO(2) enrichment stimulated above-ground growth of C(4) grasses in 2 of 3 years when soil moisture most limited plant productivity. The results indicate that in a warmer, CO(2)-enriched world, both SWC and productivity in semi-arid grasslands may be higher than previously expected.

  12. DEVELOPMENT OF A SOFTWARE DESIGN TOOL FOR HYBRID SOLAR-GEOTHERMAL HEAT PUMP SYSTEMS IN HEATING- AND COOLING-DOMINATED BUILDINGS

    SciTech Connect

    Yavuzturk, C. C.; Chiasson, A. D.; Filburn, T. P.

    2012-11-29

    This project provides an easy-to-use, menu-driven, software tool for designing hybrid solar-geothermal heat pump systems (GHP) for both heating- and cooling-dominated buildings. No such design tool currently exists. In heating-dominated buildings, the design approach takes advantage of glazed solar collectors to effectively balance the annual thermal loads on the ground with renewable solar energy. In cooling-dominated climates, the design approach takes advantage of relatively low-cost, unglazed solar collectors as the heat rejecting component. The primary benefit of hybrid GHPs is the reduced initial cost of the ground heat exchanger (GHX). Furthermore, solar thermal collectors can be used to balance the ground loads over the annual cycle, thus making the GHX fully sustainable; in heating-dominated buildings, the hybrid energy source (i.e., solar) is renewable, in contrast to a typical fossil fuel boiler or electric resistance as the hybrid component; in cooling-dominated buildings, use of unglazed solar collectors as a heat rejecter allows for passive heat rejection, in contrast to a cooling tower that consumes a significant amount of energy to operate, and hybrid GHPs can expand the market by allowing reduced GHX footprint in both heating- and cooling-dominated climates. The design tool allows for the straight-forward design of innovative GHP systems that currently pose a significant design challenge. The project lays the foundations for proper and reliable design of hybrid GHP systems, overcoming a series of difficult and cumbersome steps without the use of a system simulation approach, and without an automated optimization scheme. As new technologies and design concepts emerge, sophisticated design tools and methodologies must accompany them and be made usable for practitioners. Lack of reliable design tools results in reluctance of practitioners to implement more complex systems. A menu-driven software tool for the design of hybrid solar GHP systems is

  13. Comparative metabolic profiling between desiccation-sensitive and desiccation-tolerant species of Selaginella reveals insights into the resurrection trait

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Spike-mosses (Selaginellaceae) represent an ancient lineage of vascular plants in which some species have evolved or revolved desiccation tolerance (DT). A sister group comparison was conducted between a desiccation-tolerant species, Selaginella lepidophylla, and a desiccation-sensitive species, S. ...

  14. Tolerance to environmental desiccation in moss sperm.

    PubMed

    Shortlidge, Erin E; Rosenstiel, Todd N; Eppley, Sarah M

    2012-05-01

    • Sexual reproduction in mosses requires that sperm be released freely into the environment before finding and fertilizing a receptive female. After release from the male plant, moss sperm may experience a range of abiotic stresses; however, few data are available examining stress tolerance of moss sperm and whether there is genetic variation for stress tolerance in this important life stage. • Here, we investigated the effects of environmental desiccation and recovery on the sperm cells of three moss species (Bryum argenteum, Campylopus introflexus, and Ceratodon purpureus). • We found that a fraction of sperm cells were tolerant to environmental desiccation for extended periods (d) and that tolerance did not vary among species. We found that this tolerance occurs irrespective of ambient dehydration conditions, and that the addition of sucrose during dry-down improved cell recovery. Although we observed no interspecific variation, significant variation among individuals within species in sperm cell tolerance to environmental desiccation was observed, suggesting selection could potentially act on this basic reproductive trait. • The observation of desiccation-tolerant sperm in multiple moss species has important implications for understanding bryophyte reproduction, suggesting the presence of a significant, uncharacterized complexity in the ecology of moss mating systems.

  15. Desiccation Tolerance Studied in the Resurrection Plant Craterostigma plantagineum.

    PubMed

    Bartels, Dorothea

    2005-11-01

    This review will focus on the acquisition of desiccation tolerance in the resurrection plant Craterostigma plantagineum. Molecular aspects of desiccation tolerance in this plant will be compared with the response of non-tolerant plants to dehydration. Unique features of C. plantagineum are described like the CDT-1 (Craterostigma desiccation tolerance gene-1) gene and the carbohydrate metabolism. Abundant proteins which are associated with the desiccation tolerance phenomenon are the late embryogenesis abundant (=LEA) proteins. These proteins are very hydrophilic and occur in several other species which have acquired desiccation tolerance.

  16. Energy storage using phase-change materials for active solar heating and cooling: An evaluation of future research and development direction

    NASA Astrophysics Data System (ADS)

    Borkowski, R. J.; Stovall, T. K.; Kedl, R. J.; Tomlinson, J. J.

    1982-04-01

    The current state of the art and commercial potential of active solar heating and cooling systems for buildings, and the use of thermal energy storage with these systems are assessed. The need for advanced latent heat storage subsystems in these applications and priorities for their development are determined. Latent storage subsystems are advantageous in applications where their compactness may be exploited. It is suggested that subsystems could facilitate storage in retrofit applications in which storage would be physically impossible otherwise.

  17. Desiccant Humidity Control System Using Waste Heat of Water Source Heat Pump

    NASA Astrophysics Data System (ADS)

    Wada, Kazuki; Mashimo, Kouichi; Takahashi, Mikio; Tanaka, Kitoshi; Toya, Saburo; Tateyama, Ryotaro; Miyamoto, Kazuhiro; Yamaguchi, Masahiro

    The authors hope to develop an air-conditioning system that processes the latent heat load and the sensible heat load separately. This would enable the efficiency of the chilling unit to be improved because the temperature of the chilled water used for cooling would be higher than normal. However, if lukewarm water is used, there is insufficient cooling and dehumidification. Therefore, a dehumidifier such as a desiccant air-conditioning system is needed. Using the waste heat generated when the desiccant air-conditioning system is in operation increases efficiency. The authors are developing a prototype desiccant humidity control system that makes use of the waste heat generated by a water source heat pump. This paper describes the results of an experiment that was conducted for this prototype based on the assumption that it would be installed in an office building. The dehumidification performance achieved was sufficient to process the indoor latent heat load. The prototype was able to adjust the indoor relative humidity from 40% to 60% under conditions in which the indoor latent heat load varied. Humidification without the use of water was possible even in the absence of an indoor latent heat load when the outdoor absolute humidity was 3.5 g/kg' or more.

  18. Indirect evaporative cooler using membrane-contained, liquid desiccant for dehumidification

    SciTech Connect

    Kozubal, Eric Joseph

    2016-12-13

    An indirect evaporative cooler for cooling inlet supply air from a first temperature to a second, lower temperature using a stream of liquid coolant and a stream of exhaust or purge air. The cooler includes a first flow channel for inlet supply air and a second flow channel adjacent the first for exhaust air. The first and second flow channels are defined in part by sheets of a membrane permeable to water vapor such that mass is transferred as a vapor through the membrane from the inlet supply air to a contained liquid desiccant for dehumidification and also to the exhaust air as heat is transferred from the inlet supply air to the liquid coolant. A separation wall divides the liquid desiccant and the coolant but allows heat to be transferred from the supply air to the coolant which releases water vapor to the counter or cross flowing exhaust air.

  19. Frost Growth CFD Model of an Integrated Active Desiccant Rooftop Unit

    SciTech Connect

    Geoghegan, Patrick J; Petrov, Andrei Y; Vineyard, Edward Allan; Zaltash, Abdolreza; Linkous, Randall Lee

    2008-01-01

    A frost growth model is incorporated into a Computational Fluid Dynamics (CFD) simulation of a heat pump by means of a user-defined function in FLUENT, a commercial CFD code. The transient model is applied to the outdoor section of an Integrated Active Desiccant Rooftop (IADR) unit in heating mode. IADR is a hybrid vapor compression and active desiccant unit capable of handling 100% outdoor air (dedicated outdoor air system) or as a total conditioning system, handling both outdoor air and space cooling or heating loads. The predicted increase in flow resistance and loss in heat transfer capacity due to frost build-up are compared to experimental pressure drop readings and thermal imaging. The purpose of this work is to develop a CFD model that is capable of predicting frost growth, an invaluable tool in evaluating the effectiveness of defrost-on-demand cycles.

  20. Indirect evaporative cooler using membrane-contained, liquid desiccant for dehumidification

    DOEpatents

    Kozubal, Eric Joseph; Slayzak, Steven Joseph

    2014-07-08

    An indirect evaporative cooler for cooling inlet supply air from a first temperature to a second, lower temperature using a stream of liquid coolant and a stream of exhaust or purge air. The cooler includes a first flow channel for inlet supply air and a second flow channel adjacent the first for exhaust air. The first and second flow channels are defined in part by sheets of a membrane permeable to water vapor such that mass is transferred as a vapor through the membrane from the inlet supply air to a contained liquid desiccant for dehumidification and also to the exhaust air as heat is transferred from the inlet supply air to the liquid coolant. A separation wall divides the liquid desiccant and the coolant but allows heat to be transferred from the supply air to the coolant which releases water vapor to the counter or cross flowing exhaust air.

  1. Desiccant-Based Combined Systems: Integrated Active Desiccant Rooftop Hybrid System Development and Testing Final Report- Phase 4

    SciTech Connect

    Fischer, J

    2005-05-06

    provide individual sensible and latent loads required by an occupied space without over-cooling and reheating air. The product was developed using a housing construction similar to that of a conventional packaged rooftop unit. The resulting integrated active desiccant rooftop (IADR) is similar in size to a currently available conventional rooftop unit sized to provide an equivalent total cooling capacity. Unlike a conventional rooftop unit, the IADR can be operated as a dedicated outdoor air system processing 100% outdoor air, as well as a total conditioning system capable of handling any ratio of return air to outdoor air. As part of this R&D program, a detailed investigation compared the first cost and operating cost of the IADR with costs for a conventional packaged approach for an office building located in Jefferson City, MO. The results of this comparison suggest that the IADR approach, once commercialized, could be cost-competitive with existing technology--exhibiting a one-year to two-year payback period--while simultaneously offering improved humidity control, indoor air quality, and energy efficiency.

  2. Field Demonstration of Active Desiccant-Based Outdoor Air Preconditioning Systems, Final Report: Phase 3

    SciTech Connect

    Fischer, J.

    2001-07-09

    This report summarizes an investigation of the performance of two active desiccant cooling systems that were installed as pilot systems in two locations--a college dormitory and a research laboratory--during the fall of 1999. The laboratory system was assembled in the field from commercially available Trane air-handling modules combined with a standard total energy recovery module and a customized active desiccant wheel, both produced by SEMCO. The dormitory system was a factory-built, integrated system produced by SEMCO that included both active desiccant and sensible-only recovery wheels, a direct-fired gas regeneration section, and a pre-piped Trane heat pump condensing section. Both systems were equipped with direct digital control systems, complete with full instrumentation and remote monitoring capabilities. This report includes detailed descriptions of these two systems, installation details, samples of actual performance, and estimations of the energy savings realized. These pilot sites represent a continuation of previous active desiccant product development research (Fischer, Hallstrom, and Sand 2000; Fischer 2000). Both systems performed as anticipated, were reliable, and required minimal maintenance. The dehumidification/total-energy-recovery hybrid approach was particularly effective in all respects. System performance showed remarkable improvement in latent load handling capability and operating efficiency compared with the original conventional cooling system and with the conventional system that remained in another, identical wing of the facility. The dehumidification capacity of the pilot systems was very high, the cost of operation was very low, and the system was cost-effective, offering a simple payback for these retrofit installations of approximately 5 to 6 years. Most important, the dormitory system resolved numerous indoor air quality problems in the dormitory by providing effective humidity control and increased, continuous ventilation air.

  3. TOR and RAS pathways regulate desiccation tolerance in Saccharomyces cerevisiae

    PubMed Central

    Welch, Aaron Z.; Gibney, Patrick A.; Botstein, David; Koshland, Douglas E.

    2013-01-01

    Tolerance to desiccation in cultures of Saccharomyces cerevisiae is inducible; only one in a million cells from an exponential culture survive desiccation compared with one in five cells in stationary phase. Here we exploit the desiccation sensitivity of exponentially dividing cells to understand the stresses imposed by desiccation and their stress response pathways. We found that induction of desiccation tolerance is cell autonomous and that there is an inverse correlation between desiccation tolerance and growth rate in glucose-, ammonia-, or phosphate-limited continuous cultures. A transient heat shock induces a 5000–fold increase in desiccation tolerance, whereas hyper-ionic, -reductive, -oxidative, or -osmotic stress induced much less. Furthermore, we provide evidence that the Sch9p-regulated branch of the TOR and Ras-cAMP pathway inhibits desiccation tolerance by inhibiting the stress response transcription factors Gis1p, Msn2p, and Msn4p and by activating Sfp1p, a ribosome biogenesis transcription factor. Among 41 mutants defective in ribosome biogenesis, a subset defective in 60S showed a dramatic increase in desiccation tolerance independent of growth rate. We suggest that reduction of a specific intermediate in 60S biogenesis, resulting from conditions such as heat shock and nutrient deprivation, increases desiccation tolerance. PMID:23171550

  4. Desiccant-based dehumidification system and method

    DOEpatents

    Fischer, John C.

    2004-06-22

    The present invention provides an apparatus for dehumidifying air supplied to an enclosed space by an air conditioning unit. The apparatus includes a partition separating the interior of the housing into a supply portion and a regeneration portion. The supply portion has an inlet for receiving supply air from the air conditioning unit and an outlet for supplying air to the enclosed space. A regeneration fan creates the regeneration air stream. The apparatus includes an active desiccant wheel positioned such that a portion of the wheel extends into the supply portion and a portion of the wheel extends into the regeneration portion, so that the wheel can rotate through the supply air stream and the regeneration air stream to dehumidify the supply air stream. A heater warms the regeneration air stream as necessary to regenerate the desiccant wheel. The invention also comprises a hybrid system that combines air conditioning and dehumidifying components into a single integrated unit.

  5. Composite desiccant material "CaCl2/Vermiculite/Saw wood": a new material for fresh water production from atmospheric air

    NASA Astrophysics Data System (ADS)

    Kumar, Manoj; Yadav, Avadhesh

    2016-04-01

    In this study a novel composite desiccant material "CaCl2/Vermiculite/Saw wood" have been synthesized and tested for the water generation from atmospheric air. The vermiculite- saw wood used as a host matrix and CaCl2 as a hygroscopic salt. A solar glass desiccant box type system with a collector area of 0.36 m2 has been used. Design parameters for water generation are height of glass from the desiccant material bed as 0.22 m, inclination in angle as 30º, the effective thickness of glass as 3 mm and number of glazing as single. It has been found that the concentration of calcium chloride is the most influencing factor for fresh water generation from atmospheric air. The maximum amount of water produced by using novel composite desiccant material is 195 ml/kg/day.

  6. A review of desiccant dehumidification technology

    SciTech Connect

    Pesaran, A.A.

    1994-10-01

    This paper overviews applications of desiccant technology for dehumidifying commercial and institutional buildings. Because of various market, policy, and regulatory factors, this technology is especially attractive for dehumidification applications in the 1990s. After briefly reviewing the principle of operation, the authors present three case studies-for supermarkets, a hotel, and an office building. The authors also discuss recent advances and ongoing research and development activities.

  7. An investigation of the acceptance of solar heating and cooling in the housing industry in New Mexico

    NASA Technical Reports Server (NTRS)

    Lundahl, C. R.; Scott, J. C.; Dennis, D. M.

    1976-01-01

    A data base of information relating to the acceptability of solar-energy technology in the New Mexican housing industry was developed. Topics examined include: (1) the factors which influence the adoption of solar-energy systems in the New Mexican housing industry; (2) the degree of acceptability of various solar factors among New Mexican consumers, architects, contractors, financiers, energy suppliers, and governmental officials; and (3) the current attitudes toward the acceptability of solar energy factors in the New Mexican housing industry.

  8. Desiccation tolerance and drought acclimation in the Antarctic collembolan Cryptopygus antarcticus.

    PubMed

    Elnitsky, Michael A; Benoit, Joshua B; Denlinger, David L; Lee, Richard E

    2008-01-01

    The availability of water is recognized as the most important determinant of the distribution and activity of terrestrial organisms within the maritime Antarctic. Within this environment, arthropods may be challenged by drought stress during both the austral summer, due to increased temperature, wind, insolation, and extended periods of reduced precipitation, and the winter, as a result of vapor pressure gradients between the surrounding icy environment and the body fluids. The purpose of the present study was to assess the desiccation tolerance of the Antarctic springtail, Cryptopygus antarcticus, under ecologically-relevant conditions characteristic of both summer and winter along the Antarctic Peninsula. In addition, this study examined the physiological changes and effects of mild drought acclimation on the subsequent desiccation tolerance of C. antarcticus. The collembolans possessed little resistance to water loss under dry air, as the rate of water loss was >20% h(-1) at 0% relative humidity (RH) and 4 degrees C. Even under ecologically-relevant desiccating conditions, the springtails lost water at all relative humidities below saturation (100% RH). However, slow dehydration at high RH dramatically increased the desiccation tolerance of C. antarcticus, as the springtails tolerated a greater loss of body water. Relative to animals maintained at 100% RH, a mild drought acclimation at 98.2% RH significantly increased subsequent desiccation tolerance. Drought acclimation was accompanied by the synthesis and accumulation of several sugars and polyols that could function to stabilize membranes and proteins during dehydration. Drought acclimation may permit C. antarcticus to maintain activity and thereby allow sufficient time to utilize behavioral strategies to reduce water loss during periods of reduced moisture availability. The springtails were also susceptible to desiccation at subzero temperatures in equilibrium with the vapor pressure of ice; they lost

  9. Design, fabrication, testing and delivery of a solar collector

    NASA Technical Reports Server (NTRS)

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

    1976-01-01

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

  10. Proteome analysis of leaves of the desiccation-tolerant grass, sporobolus stapfianus, in response to desiccation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sporobolus stapfianus is a resurrection grass native to South Africa which can tolerate the complete drying of its vegetative tissue structure; i.e., desiccation, and recover fully within hours of rewetting. Gene expression studies have demonstrated that the grass employs a strategy of gene inductio...

  11. Vehicle cabin cooling system for capturing and exhausting heated boundary layer air from inner surfaces of solar heated windows

    DOEpatents

    Farrington, Robert B.; Anderson, Ren

    2001-01-01

    The cabin cooling system includes a cooling duct positioned proximate and above upper edges of one or more windows of a vehicle to exhaust hot air as the air is heated by inner surfaces of the windows and forms thin boundary layers of heated air adjacent the heated windows. The cabin cooling system includes at least one fan to draw the hot air into the cooling duct at a flow rate that captures the hot air in the boundary layer without capturing a significant portion of the cooler cabin interior air and to discharge the hot air at a point outside the vehicle cabin, such as the vehicle trunk. In a preferred embodiment, the cooling duct has a cross-sectional area that gradually increases from a distal point to a proximal point to the fan inlet to develop a substantially uniform pressure drop along the length of the cooling duct. Correspondingly, this cross-sectional configuration develops a uniform suction pressure and uniform flow rate at the upper edge of the window to capture the hot air in the boundary layer adjacent each window.

  12. Molecular mechanisms of desiccation tolerance in resurrection plants.

    PubMed

    Gechev, Tsanko S; Dinakar, Challabathula; Benina, Maria; Toneva, Valentina; Bartels, Dorothea

    2012-10-01

    Resurrection plants are a small but diverse group of land plants characterized by their tolerance to extreme drought or desiccation. They have the unique ability to survive months to years without water, lose most of the free water in their vegetative tissues, fall into anabiosis, and, upon rewatering, quickly regain normal activity. Thus, they are fundamentally different from other drought-surviving plants such as succulents or ephemerals, which cope with drought by maintaining higher steady state water potential or via a short life cycle, respectively. This review describes the unique physiological and molecular adaptations of resurrection plants enabling them to withstand long periods of desiccation. The recent transcriptome analysis of Craterostigma plantagineum and Haberlea rhodopensis under drought, desiccation, and subsequent rehydration revealed common genetic pathways with other desiccation-tolerant species as well as unique genes that might contribute to the outstanding desiccation tolerance of the two resurrection species. While some of the molecular responses appear to be common for both drought stress and desiccation, resurrection plants also possess genes that are highly induced or repressed during desiccation with no apparent sequence homologies to genes of other species. Thus, resurrection plants are potential sources for gene discovery. Further proteome and metabolome analyses of the resurrection plants contributed to a better understanding of molecular mechanisms that are involved in surviving severe water loss. Understanding the cellular mechanisms of desiccation tolerance in this unique group of plants may enable future molecular improvement of drought tolerance in crop plants.

  13. Effect of supply/regeneration section area ratio on the performance of desiccant wheels in hot and humid climates: an experimental investigation

    NASA Astrophysics Data System (ADS)

    Zendehboudi, Alireza; Esmaeili, Hossein

    2016-06-01

    Desiccant cooling system is a suitable alternative option for conventional cooling system in humid climates. It is an environmental protection technique for cooling buildings. This study has investigated the effect of supply/regeneration section area ratio on the performance of desiccant wheels in hot and humid climates, using Silica Gel (WSG) and Molecular Sieve (LT3) desiccants. To this end, some parameters such as outlet air humidity ratio, process removed moisture, process outlet temperature, reactivation outlet temperature and reactivation outlet moisture have been examined as a function of rotational speed and inlet air humidity ratio in 1:3, 1:2 and 1:1 split. In this study, desiccant materials are regenerated using a constant regeneration temperature of 80 °C, wheel rotation speed range of 4-12 RPH (revolutions per hour) and variable humidity. The results show that a rise in area ratio causes an increase in process removed moisture, process outlet temperature, reactivation outlet temperature and a drop in reactivation outlet moisture and outlet humidity ratio of process air.

  14. Research and Development of a Small-Scale Adsorption Cooling System

    NASA Astrophysics Data System (ADS)

    Gupta, Yeshpal

    The world is grappling with two serious issues related to energy and climate change. The use of solar energy is receiving much attention due to its potential as one of the solutions. Air conditioning is particularly attractive as a solar energy application because of the near coincidence of peak cooling loads with the available solar power. Recently, researchers have started serious discussions of using adsorptive processes for refrigeration and heat pumps. There is some success for the >100 ton adsorption systems but none exists in the <10 ton size range required for residential air conditioning. There are myriad reasons for the lack of small-scale systems such as low Coefficient of Performance (COP), high capital cost, scalability, and limited performance data. A numerical model to simulate an adsorption system was developed and its performance was compared with similar thermal-powered systems. Results showed that both the adsorption and absorption systems provide equal cooling capacity for a driving temperature range of 70--120 ºC, but the adsorption system is the only system to deliver cooling at temperatures below 65 ºC. Additionally, the absorption and desiccant systems provide better COP at low temperatures, but the COP's of the three systems converge at higher regeneration temperatures. To further investigate the viability of solar-powered heat pump systems, an hourly building load simulation was developed for a single-family house in the Phoenix metropolitan area. Thermal as well as economic performance comparison was conducted for adsorption, absorption, and solar photovoltaic (PV) powered vapor compression systems for a range of solar collector area and storage capacity. The results showed that for a small collector area, solar PV is more cost-effective whereas adsorption is better than absorption for larger collector area. The optimum solar collector area and the storage size were determined for each type of solar system. As part of this dissertation

  15. Desiccation tolerance of Sphagnum revisited: a puzzle resolved.

    PubMed

    Hájek, T; Vicherová, E

    2014-07-01

    As ecosystem engineers, Sphagnum mosses control their surroundings through water retention, acidification and peat accumulation. Because water retention avoids desiccation, sphagna are generally intolerant to drought; however, the literature on Sphagnum desiccation tolerance (DT) provides puzzling results, indicating the inducible nature of their DT. To test this, various Sphagnum species and other mesic bryophytes were hardened to drought by (i) slow drying; (ii) ABA application and (iii) chilling or frost. DT tolerance was assessed as recovery of chlorophyll fluorescence parameters after severe desiccation. We monitored the seasonal course of DT in bog bryophytes. Under laboratory conditions, following initial de-hardening, untreated Sphagnum shoots lacked DT; however, DT was induced by all hardening treatments except chilling, notably by slow drying, and in Sphagnum species of the section Cuspidata. In the field, sphagna in hollows and lawns developed DT several times during the growing season, responding to reduced precipitation and a lowered water table. Hummock and aquatic species developed DT only in late autumn, probably as a response to frost. Sphagnum protonemata failed to develop DT; hence, desiccation may limit Sphagnum establishment in drier habitats with suitable substrate chemistry. Desiccation avoiders among sphagna form compact hummocks or live submerged; thus, they do not develop DT in the field, lacking the initial desiccation experience, which is frequent in hollow and lawn habitats. We confirmed the morpho-physiological trade-off: in contrast to typical hollow sphagna, hummock species invest more resources in water retention (desiccation avoidance), while they have a lower ability to develop physiological DT.

  16. Desiccation of the resurrection plant Haberlea rhodopensis at high temperature.

    PubMed

    Mihailova, Gergana; Petkova, Snejana; Büchel, Claudia; Georgieva, Katya

    2011-05-01

    Haberlea rhodopensis plants, growing under low irradiance in their natural habitat, were desiccated to air-dry state at a similar light intensity (about 30 μmol m(-2) s(-1)) under optimal (23/20°C, day/night) or high (38/30°C) temperature. Dehydration of plants at high temperature increased the rate of water loss threefold and had a more detrimental effect than either drought or high temperature alone. Water deficit decreased the photochemical activity of PSII and PSI and the rate of photosynthetic oxygen evolution, and these effects were stronger when desiccation was carried out at 38°C. Some reduction in the amount of the main PSI and PSII proteins was observed especially in severely desiccated Haberlea leaves. The results clearly showed that desiccation of the homoiochlorophyllous poikilohydric plant Haberlea rhodopensis at high temperature had more damaging effects than desiccation at optimal temperature and in addition recovery was slower. Increased thermal energy dissipation together with higher proline and carotenoid content in the course of desiccation at 38°C compared to desiccation at 23°C probably helped in overcoming the stress.

  17. Breathing air purification; Desiccant vs. refrigerated

    SciTech Connect

    McKay, K.L.; Swanson, A.L. )

    1986-07-01

    Carbon monoxide (CO) is a common contaminant of ambient air - levels as high as 200 ppm are not uncommon in urban, industrial, or high automotive-traffic areas. Carbon monoxide may also be produced by the oxidation of lubricating oil in overheated compressors. Air from an oil-lubricated compressor, even when an aftercooler is used, often contains significant quantities of oil mist and vapor. Even where a breathing air (non-oil-lubricated) compressor is used , oil. levels in the air taken into the compressor can still exceed Grade D standards, especially in industrial environments. Other contaminants (gaseous hydrocarbons, particulate matter, and odors), while not addressed by the Grade D criteria, are also present in harmful or objectionable levels in industrial environments; therefore, they must be taken into account in the design of the air purification systems. This paper discusses two basic types of breathing air purifiers: desiccant and refrigerated purifiers.

  18. Meteoritic Constraints on Temperatures, Pressures, Cooling Rates, Chemical Compositions and Modes of Condensation in the Solar Nebula

    NASA Astrophysics Data System (ADS)

    Petaev, M. I.; Wood, J. A.

    2005-12-01

    Monotonic, equilibrium condensation of nebular materials from a chemically homogeneous solar nebula is unlikely. Condensation of nebular gas was quite rapid, resulting in significant deviations from chemical equilibrium between condensed phases and the residual gas. A few primitive nebular components condensed from a gas of solar composition; most of them formed in fractionated nebular systems. Local chemical variations caused by both depletion and enrichment in dust relative to gas were commonplace in the solar nebula. Local variations of nebular pressure were, in general, in the range of ~10-4 - 6×10-6 bar. Short-lived temperature excursions might have exceeded 2000 K, with the sustained temperatures in the 16O-rich nebular source regions of CAIs and AOAs being in the range of 1230-1350 K. Silicate melts might have been temporarily stable in nebular source regions heavily enriched in dust.

  19. Economic analysis of the integrated heating and cooling potential of a residential passive-solar water wall design

    NASA Astrophysics Data System (ADS)

    Roach, F.; Mangeng, C.; Kirschner, C.; Ben-David, S.

    Preliminary performance estimates for the heating and cooling potential of water walls were made. These estimates include the Btu displacement that is attributable to a 300-square foot water wall design in a 1200-square foot residence. The design is for a forced ventalation water wall system that includes the fans and ducting necessary to achieve a 3000-cfm flow of air. The cooling and heating energy displacement estimates are combined with appropriate region-specific fuel prices, system costs, and general economic parameters in a lifecycle cost analysis of this fixed-size water wall design. The economic indicators used to discusse the results include net present value and a total cost goal. Input data and results are presented in mapped form and used to assess the energy savings potential of the water wall in 220 regions of the continental United States.

  20. Liquid Desiccant in Air Conditioners: Nano-Engineered Porous Hollow Fiber Membrane-Based Air Conditioning System

    SciTech Connect

    2010-09-02

    BEETIT Project: UTRC is developing an air conditioning system that is optimized for use in warm and humid climates. UTRC’s air conditioning system integrates a liquid drying agent or desiccant and a traditional vapor compression system found in 90% of air conditioners. The drying agent reduces the humidity in the air before it is cooled, using less energy. The technology uses a membrane as a barrier between the air and the liquid salt stream allowing only water vapor to pass through and not the salt molecules. This solves an inherent problem with traditional liquid desiccant systems—carryover of the liquid drying agent into the conditioned air stream—which eliminates corrosion and health issues

  1. Research Proposal for the Design and Engineering Phase of a Solar Heating and Cooling System Experiment at the Warner Robins Public Library, Warner Robins, Georgia. Submitted to the United States Energy Research and Development Administration.

    ERIC Educational Resources Information Center

    Phillips, Warren H.; And Others

    A number of reasons are advanced to include a solar heating and cooling experiment in a library building. The unique aspects of the experiment are to be a seasonally adjustable collector tilt and testing of a new generation of absorption air conditioners. After a brief description of the proposed experiment, the proposal contains forms filed by…

  2. Effect of desiccation of marine environment on beam structure

    NASA Astrophysics Data System (ADS)

    Chen, Da; Wang, Na; Hou, Li-jun; Liao, Ying-di

    2013-03-01

    This paper presents the study on the effect of desiccation for different part of offshore structure corresponding to the water level. A coupled elastoplastic damage model is proposed to describe the mechanical behavior of cement-based materials under external loading and desiccation, in which both the plastic and damage behaviors under multi-axial stress are considered in composition with the desiccation effect. The comparison between numerical simulation and experimental data indicates that the proposed model can well predict the mechanical characteristics of cement-based materials with different saturations. In addition, a series of small beams subjected to desiccation are further analyzed to reveal the response of structure in the drying process.

  3. Genetic Analysis of Desiccation Tolerance in Saccharomyces cerevisiae

    PubMed Central

    Calahan, Dean; Dunham, Maitreya; DeSevo, Chris; Koshland, Douglas E.

    2011-01-01

    Desiccation tolerance, the ability to survive nearly total dehydration, is a rare strategy for survival and reproduction observed in all taxa. However, the mechanism and regulation of this phenomenon are poorly understood. Correlations between desiccation tolerance and potential effectors have been reported in many species, but their physiological significance has not been established in vivo. Although the budding yeast Saccharomyces cerevisiae exhibits extreme desiccation tolerance, its usefulness has been hampered by an inability to reduce tolerance more than a few fold by physiological or genetic perturbations. Here we report that fewer than one in a million yeast cells from low-density logarithmic cultures survive desiccation, while 20–40% of cells from saturated cultures survive. Using this greatly expanded metric, we show that mutants defective in trehalose biosynthesis, hydrophilins, responses to hyperosmolarity, and hypersalinity, reactive oxygen species (ROS) scavenging and DNA damage repair nevertheless retain wild-type levels of desiccation tolerance, suggesting that this trait involves a unique constellation of stress factors. A genome-wide screen for mutants that render stationary cells as sensitive as log phase cells identifies only mutations that block respiration. Respiration as a prerequisite for acquiring desiccation tolerance is corroborated by respiration inhibition and by growth on nonfermentable carbon sources. Suppressors bypassing the respiration requirement for desiccation tolerance reveal at least two pathways, one of which, involving the Mediator transcription complex, is associated with the shift from fermentative to respiratory metabolism. Further study of these regulators and their targets should provide important clues to the sensors and effectors of desiccation tolerance. PMID:21840858

  4. Parametric study of thermal storage containing rocks or fluid filled cans for solar heating and cooling, phase 2

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1981-01-01

    The test data and an analysis of the heat transfer characteristics of a solar thermal energy storage bed utilizing water filled cans and standard bricks as energy storage medium are presented. This experimental investigation was initiated to find a usable heat intensive solar thermal storage device other than rock storage and water tank. Four different sizes of soup cans were stacked in a chamber in three different arrangements-vertical, horizontal, and random. Air is used as transfer medium for charging and discharge modes at three different mass flow rates and inlet air temperature respectively. These results are analyzed and compared, which show that a vertical stacking and medium size cans with Length/Diameter (L/D) ratio close to one have better average characteristics of heat transfer and pressure drop.

  5. Heterogeneity in Desiccated Solutions: Implications for Biostabilization

    PubMed Central

    Ragoonanan, Vishard; Aksan, Alptekin

    2008-01-01

    Biopreservation processes such as freezing and drying inherently introduce heterogeneity. We focused on exploring the mechanisms responsible for heterogeneity in isothermal, diffusively dried biopreservation solutions that contain a model protein. The biopreservation solutions used contained trehalose (a sugar known for its stabilization effect) and salts (LiCl, NaCl, MgCl2, and CaCl2). Performing Fourier transform infrared spectroscopy analysis on the desiccated droplets, spatial distributions of the components within the dried droplet, as well as their specific interactions, were investigated. It was established that the formation of multiple thermodynamic states was induced by the spatial variations in the cosolute concentration gradients, directly affecting the final structure of the preserved protein. The spatial distribution gradients were formed by two competing flows that formed within the drying droplet: a dominant peripheral flow, induced by contact line pinning, and the Marangoni flow, induced by surface tension gradients. It was found that the changes in cosolute concentrations and drying conditions affected the spatial heterogeneity and stability of the product. It was also found that trehalose and salts had a synergistic stabilizing effect on the protein structure, which originated from destructuring of the vicinal water, which in turn mediated the interactions of trehalose with the protein. This interaction was observed by the change in the glycosidic CO, and the CH stretch vibrations of the trehalose molecule. PMID:18055531

  6. Solar energy

    NASA Technical Reports Server (NTRS)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  7. Developing sporophytes transition from an inducible to a constitutive ecological strategy of desiccation tolerance in the moss Aloina ambigua: effects of desiccation on fitness

    PubMed Central

    Stark, Lloyd R.; Brinda, John C.

    2015-01-01

    Background and Aims Two ecological strategies of desiccation tolerance exist in plants, constitutive and inducible. Because of difficulties in culturing sporophytes, very little is known about desiccation tolerance in this generation and how desiccation affects sexual fitness. Methods Cultured sporophytes and vegetative shoots from a single genotype of the moss Aloina ambigua raised in the laboratory were tested for their strategy of desiccation tolerance by desiccating the shoot–sporophyte complex and vegetative shoots at different intensities, and comparing outcomes with those of undried shoot–sporophyte complexes and vegetative shoots. By using a dehardened clonal line, the effects of field, age and genetic variance among plants were removed. Key Results The gametophyte and embryonic sporophyte were found to employ a predominantly inducible strategy of desiccation tolerance, while the post-embryonic sporophyte was found to employ a moderately constitutive strategy of desiccation tolerance. Further, desiccation reduced sporophyte fitness, as measured by sporophyte mass, seta length and capsule size. However, the effects of desiccation on sporophyte fitness were reduced if the stress occurred during embryonic development as opposed to postembryonic desiccation. Conclusions The effects of desiccation on dehardened sporophytes of a bryophyte are shown for the first time. The transition from one desiccation tolerance strategy to the other in a single structure or generation is shown for only the second time in plants and for the first time in bryophytes. Finding degrees of inducible strategies of desiccation tolerance in different life phases prompts the formulation of a continuum hypothesis of ecological desiccation tolerance in mosses, where desiccation tolerance is not an either/or phenomenon, but varies in degree along a gradient of ecological inducibility. PMID:25578378

  8. Solar energy: Program summary document

    NASA Astrophysics Data System (ADS)

    1980-08-01

    Solar programs and the eight solar technologies are discussed, including biomass energy systems, photovoltaic energy systems, wind energy conversion systems, solar thermal power, ocean systems, agricultural and industrial process heat, active solar heating and cooling, passive and hybrid solar heating and cooling.

  9. Insect capa neuropeptides impact desiccation and cold tolerance

    PubMed Central

    Terhzaz, Selim; Teets, Nicholas M.; Cabrero, Pablo; Henderson, Louise; Ritchie, Michael G.; Nachman, Ronald J.; Dow, Julian A. T.; Denlinger, David L.; Davies, Shireen-A.

    2015-01-01

    The success of insects is linked to their impressive tolerance to environmental stress, but little is known about how such responses are mediated by the neuroendocrine system. Here we show that the capability (capa) neuropeptide gene is a desiccation- and cold stress-responsive gene in diverse dipteran species. Using targeted in vivo gene silencing, physiological manipulations, stress-tolerance assays, and rationally designed neuropeptide analogs, we demonstrate that the Drosophila melanogaster capa neuropeptide gene and its encoded peptides alter desiccation and cold tolerance. Knockdown of the capa gene increases desiccation tolerance but lengthens chill coma recovery time, and injection of capa peptide analogs can reverse both phenotypes. Immunohistochemical staining suggests that capa accumulates in the capa-expressing Va neurons during desiccation and nonlethal cold stress but is not released until recovery from each stress. Our results also suggest that regulation of cellular ion and water homeostasis mediated by capa peptide signaling in the insect Malpighian (renal) tubules is a key physiological mechanism during recovery from desiccation and cold stress. This work augments our understanding of how stress tolerance is mediated by neuroendocrine signaling and illustrates the use of rationally designed peptide analogs as agents for disrupting protective stress tolerance. PMID:25730885

  10. Insect capa neuropeptides impact desiccation and cold tolerance.

    PubMed

    Terhzaz, Selim; Teets, Nicholas M; Cabrero, Pablo; Henderson, Louise; Ritchie, Michael G; Nachman, Ronald J; Dow, Julian A T; Denlinger, David L; Davies, Shireen-A

    2015-03-03

    The success of insects is linked to their impressive tolerance to environmental stress, but little is known about how such responses are mediated by the neuroendocrine system. Here we show that the capability (capa) neuropeptide gene is a desiccation- and cold stress-responsive gene in diverse dipteran species. Using targeted in vivo gene silencing, physiological manipulations, stress-tolerance assays, and rationally designed neuropeptide analogs, we demonstrate that the Drosophila melanogaster capa neuropeptide gene and its encoded peptides alter desiccation and cold tolerance. Knockdown of the capa gene increases desiccation tolerance but lengthens chill coma recovery time, and injection of capa peptide analogs can reverse both phenotypes. Immunohistochemical staining suggests that capa accumulates in the capa-expressing Va neurons during desiccation and nonlethal cold stress but is not released until recovery from each stress. Our results also suggest that regulation of cellular ion and water homeostasis mediated by capa peptide signaling in the insect Malpighian (renal) tubules is a key physiological mechanism during recovery from desiccation and cold stress. This work augments our understanding of how stress tolerance is mediated by neuroendocrine signaling and illustrates the use of rationally designed peptide analogs as agents for disrupting protective stress tolerance.

  11. Stochastic Cooling

    SciTech Connect

    Blaskiewicz, M.

    2011-01-01

    Stochastic Cooling was invented by Simon van der Meer and was demonstrated at the CERN ISR and ICE (Initial Cooling Experiment). Operational systems were developed at Fermilab and CERN. A complete theory of cooling of unbunched beams was developed, and was applied at CERN and Fermilab. Several new and existing rings employ coasting beam cooling. Bunched beam cooling was demonstrated in ICE and has been observed in several rings designed for coasting beam cooling. High energy bunched beams have proven more difficult. Signal suppression was achieved in the Tevatron, though operational cooling was not pursued at Fermilab. Longitudinal cooling was achieved in the RHIC collider. More recently a vertical cooling system in RHIC cooled both transverse dimensions via betatron coupling.

  12. Bacterial survival responses to extreme desiccation and high humidity

    NASA Astrophysics Data System (ADS)

    Yang, Yinjie; Yokobori, Shinichi; Yamagishi, Akihiko

    The presence of water is thought to be essential for life and strongly considered in life searching operation on extraterrestrial planets. In this study we show different survival responses of bacterial species to water availability and temperatures (25, 4 and - 70 o C). At these temperatures, E.coli lost viability much faster under extreme desiccation than under high humidity. Deinococcus radiodurans exhibited much higher survival rate under desiccation than under high humidity at 25 o C, while its survivals under desiccation and high humidity increased to the same level at 4 and - 70 o C. Bacillus pumilus spores generally survived well under all tested conditions. Water is favorable for the survival of most microorganisms but not a "safeguard" for all microorganisms. Microbial survival at low temperatures may not be affected by water availability. Water absence should not preclude us from seeking life on other planets.

  13. Function of desiccate in gustatory sensilla of drosophila melanogaster

    PubMed Central

    Kawano, Takeshi; Ryuda, Masasuke; Matsumoto, Hitoshi; Ochiai, Masanori; Oda, Yasunori; Tanimura, Teiichi; Csikos, Gyorge; Moriya, Megumi; Hayakawa, Yoichi

    2015-01-01

    Desiccate (Desi), initially discovered as a gene expressing in the epidermis of Drosophila larvae for protection from desiccation stress, was recently found to be robustly expressed in the adult labellum; however, the function, as well as precise expression sites, was unknown. Here, we found that Desi is expressed in two different types of non-neuronal cells of the labellum, the epidermis and thecogen accessory cells. Labellar Desi expression was significantly elevated under arid conditions, accompanied by an increase in water ingestion by adults. Desi overexpression also promoted water ingestion. In contrast, a knockdown of Desi expression reduced feeding as well as water ingestion due to a drastic decrease in the gustatory sensillar sensitivity for all tested tastants. These results indicate that Desi helps protect insects from desiccation damage by not only preventing dehydration through the integument but also accelerating water ingestion via elevated taste sensitivities of the sensilla. PMID:26610608

  14. Study of corrosion in multimetallic systems. Task 2 of solar collector studies for solar heating and cooling applications. Final technical progress report

    SciTech Connect

    Diegle, R B

    1980-04-11

    Corrosion measurements were made on candidate alloys of construction for non-concentrating solar collectors under simulated conditions of collector operation. Materials evaluated were aluminum alloys 1100, 3003, and 6061, copper alloy 122, Type 444 stainless steel, and 1018 plain carbon steel. The solutions used were equivolume mixtures of ethylene glycol and water, and propylene glycol and water. They were used without corrosion inhibitors but with addition of chloride, sulfate, and bicarbonate ions. The influences of dissolved oxygen, solution flow velocity, and heat transfer were evaluated. Corrosion morphologies investigated were general attack, pitting, crevice corrosion, and galvanic corrosion. Experimental results indicated that aluminum alloys can experience severe pitting and crevice corrosion at chloride concentrations approaching 50 ppM. The corrosion rate of copper exceeded about 100 ..mu..m/yr in ethylene glycol solutions and about 80 ..mu..m/yr in propylene glycol solutions. Crevice corrosion was not observed for copper, but severe galvanic corrosion occurred when it was coupled to T444 stainless steel. T444 steel corroded at rates of less than 1 ..mu..m/yr under all exposure conditions. During circulation at 100 C in the presence of air, ethylene glycol solutions acidified because of degradation of the glycol. The initial pH of propylene glycol solutions was already low, about 4.5. The inherent corrosivity of propylene glycol was somewhat less than that of ethylene glycol, although this difference was usually less than a factor of two in measured corrosion rates. It was concluded that he corrosion rates of aluminum alloys and copper were prohibitively high in uninhibited glycol solutions, and that corrosion inhibitors are definitely necessary in operating systems.

  15. Using liquid desiccant as a regenerable filter for capturing and deactivating contaminants

    DOEpatents

    Slayzak, Steven J.; Anderson, Ren S.; Judkoff, Ronald D.; Blake, Daniel M.; Vinzant, Todd B.; Ryan, Joseph P.

    2007-12-11

    A method, and systems for implementing such method, for purifying and conditioning air of weaponized contaminants. The method includes wetting a filter packing media with a salt-based liquid desiccant, such as water with a high concentration of lithium chloride. Air is passed through the wetted filter packing media and the contaminants in are captured with the liquid desiccant while the liquid desiccant dehumidifies the air. The captured contaminants are then deactivated in the liquid desiccant, which may include heating the liquid desiccant. The liquid desiccant is regenerated by applying heat to the liquid desiccant and then removing moisture. The method includes repeating the wetting with the regenerated liquid desiccant which provides a regenerable filtering process that captures and deactivates contaminants on an ongoing basis while also conditioning the air. The method may include filtration effectiveness enhancement by electrostatic or inertial means.

  16. Traits underpinning desiccation resistance explain distribution patterns of terrestrial isopods.

    PubMed

    Dias, André T C; Krab, Eveline J; Mariën, Janine; Zimmer, Martin; Cornelissen, Johannes H C; Ellers, Jacintha; Wardle, David A; Berg, Matty P

    2013-07-01

    Predicted changes in soil water availability regimes with climate and land-use change will impact the community of functionally important soil organisms, such as macro-detritivores. Identifying and quantifying the functional traits that underlie interspecific differences in desiccation resistance will enhance our ability to predict both macro-detritivore community responses to changing water regimes and the consequences of the associated species shifts for organic matter turnover. Using path analysis, we tested (1) how interspecific differences in desiccation resistance among 22 northwestern European terrestrial isopod species could be explained by three underlying traits measured under standard laboratory conditions, namely, body ventral surface area, water loss rate and fatal water loss; (2) whether these relationships were robust to contrasting experimental conditions and to the phylogenetic relatedness effects being excluded; (3) whether desiccation resistance and hypothesized underlying traits could explain species distribution patterns in relation to site water availability. Water loss rate and (secondarily) fatal water loss together explained 90% of the interspecific variation in desiccation resistance. Our path model indicated that body surface area affects desiccation resistance only indirectly via changes in water loss rate. Our results also show that soil moisture determines isopod species distributions by filtering them according to traits underpinning desiccation resistance. These findings reveal that it is possible to use functional traits measured under standard conditions to predict soil biota responses to water availability in the field over broad spatial scales. Taken together, our results demonstrate an increasing need to generate mechanistic models to predict the effect of global changes on functionally important organisms.

  17. Solar Collectors

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Solar Energy's solar panels are collectors for a solar energy system which provides heating for a drive-in bank in Akron, OH. Collectors were designed and manufactured by Solar Energy Products, a firm established by three former NASA employees. Company President, Frank Rom, an example of a personnel-type technology transfer, was a Research Director at Lewis Research Center, which conducts extensive solar heating and cooling research, including development and testing of high-efficiency flat-plate collectors. Rom acquired solar energy expertise which helped the company develop two types of collectors, one for use in domestic/commercial heating systems and the other for drying grain.

  18. Value of Desiccated Swabs for Streptococcal Epidemiology in the Field

    PubMed Central

    Taplin, David; Lansdell, Lyle

    1973-01-01

    Streptococcal surveys in foreign countries or remote areas may be greatly enhanced by the use of calcium alginate swabs desiccated in sterile silica gel. Delays of up to 4 weeks before return to a base laboratory are feasible, and the need for fresh media or laboratory facilities in the field may be eliminated. Comparison of direct plating on crystal violet blood agar versus delayed silica gel preservation during surveys in Uganda, Haiti, Colombia, and Miami, Fla., showed no significant loss of positive cultures from skin lesions and suggests that desiccated swabs increase the recovery of bacitracin-sensitive Streptococcus pyogenes (presumptive group A) from throats. PMID:4346975

  19. Performance Evaluation of a 4.5 kW (1.3 Refrigeration Tons) Air-Cooled Lithium Bromide/Water Solar Powered (Hot-Water-Fired) Absorption Unit

    SciTech Connect

    Zaltash, Abdolreza; Petrov, Andrei Y; Linkous, Randall Lee; Vineyard, Edward Allan

    2007-01-01

    During the summer months, air-conditioning (cooling) is the single largest use of electricity in both residential and commercial buildings with the major impact on peak electric demand. Improved air-conditioning technology has by far the greatest potential impact on the electric industry compared to any other technology that uses electricity. Thermally activated absorption air-conditioning (absorption chillers) can provide overall peak load reduction and electric grid relief for summer peak demand. This innovative absorption technology is based on integrated rotating heat exchangers to enhance heat and mass transfer resulting in a potential reduction of size, cost, and weight of the "next generation" absorption units. Rotartica Absorption Chiller (RAC) is a 4.5 kW (1.3 refrigeration tons or RT) air-cooled lithium bromide (LiBr)/water unit powered by hot water generated using the solar energy and/or waste heat. Typically LiBr/water absorption chillers are water-cooled units which use a cooling tower to reject heat. Cooling towers require a large amount of space, increase start-up and maintenance costs. However, RAC is an air-cooled absorption chiller (no cooling tower). The purpose of this evaluation is to verify RAC performance by comparing the Coefficient of Performance (COP or ratio of cooling capacity to energy input) and the cooling capacity results with those of the manufacturer. The performance of the RAC was tested at Oak Ridge National Laboratory (ORNL) in a controlled environment at various hot and chilled water flow rates, air handler flow rates, and ambient temperatures. Temperature probes, mass flow meters, rotational speed measuring device, pressure transducers, and a web camera mounted inside the unit were used to monitor the RAC via a web control-based data acquisition system using Automated Logic Controller (ALC). Results showed a COP and cooling capacity of approximately 0.58 and 3.7 kW respectively at 35 C (95 F) design condition for ambient

  20. Inheritance of seed desiccation sensitivity in a coffee interspecific cross: evidence for polygenic determinism.

    PubMed

    Dussert, Stéphane; Engelmann, Florent; Louarn, Jacques; Noirot, Michel

    2004-07-01

    The genetic determinism of seed desiccation sensitivity was studied using a cross between two coffee species exhibiting a large difference for this trait, Coffea pseudozanguebariae (tolerant) and C. liberica (sensitive). Throughout the whole study, seed desiccation tolerance was quantified both in terms of water content and water activity. Whatever the parameter used, the level of seed desiccation tolerance in F1 hybrids corresponded to that of the mid-parent, thus indicating an additive inheritance of seed desiccation tolerance at the F1 level. A broad variation was observed among hybrids backcrossed to C. liberica (BCs) for seed desiccation tolerance, independent of the parameter used to quantify it. This variation was continuous and BCs showed transgression in the direction of the most desiccation sensitive parent, indicating (i) that desiccation tolerance is a polygenic trait in coffee species, and (ii) that C. pseudozanguebariae does not present the most favourable alleles for all the genes involved in seed desiccation tolerance. No significant difference was observed between the two reciprocal backcrosses, F1xC. liberica and C. libericaxF1, for the level of desiccation tolerance of their seeds, showing the absence of a maternal effect on this trait. There was no significant effect of the number of seeds harvested from each BC on the level of desiccation tolerance of its seeds. Moreover, there was no significant correlation within BCs between seed size, seed viability, and water content before desiccation and desiccation tolerance.

  1. Halophilic Archaea: Life with Desiccation, Radiation and Oligotrophy over Geological Times.

    PubMed

    Stan-Lotter, Helga; Fendrihan, Sergiu

    2015-07-28

    Halophilic archaebacteria (Haloarchaea) can survive extreme desiccation, starvation and radiation, sometimes apparently for millions of years. Several of the strategies that are involved appear specific for Haloarchaea (for example, the formation of halomucin, survival in fluid inclusions of halite), and some are known from other prokaryotes (dwarfing of cells, reduction of ATP). Several newly-discovered haloarchaeal strategies that were inferred to possibly promote long-term survival-halomucin, polyploidy, usage of DNA as a phosphate storage polymer, production of spherical dormant stages-remain to be characterized in detail. More information on potential strategies is desirable, since evidence for the presence of halite on Mars and on several moons in the solar system increased interest in halophiles with respect to the search for extraterrestrial life. This review deals in particular with novel findings and hypotheses on haloarchaeal long-term survival.

  2. Halophilic Archaea: Life with Desiccation, Radiation and Oligotrophy over Geological Times

    PubMed Central

    Stan-Lotter, Helga; Fendrihan, Sergiu

    2015-01-01

    Halophilic archaebacteria (Haloarchaea) can survive extreme desiccation, starvation and radiation, sometimes apparently for millions of years. Several of the strategies that are involved appear specific for Haloarchaea (for example, the formation of halomucin, survival in fluid inclusions of halite), and some are known from other prokaryotes (dwarfing of cells, reduction of ATP). Several newly-discovered haloarchaeal strategies that were inferred to possibly promote long-term survival—halomucin, polyploidy, usage of DNA as a phosphate storage polymer, production of spherical dormant stages—remain to be characterized in detail. More information on potential strategies is desirable, since evidence for the presence of halite on Mars and on several moons in the solar system increased interest in halophiles with respect to the search for extraterrestrial life. This review deals in particular with novel findings and hypotheses on haloarchaeal long-term survival. PMID:26226005

  3. Effect of Desiccating Stress on Mouse Meibomian Gland Function

    PubMed Central

    Suhalim, Jeffrey L.; Parfitt, Geraint J.; Xie, Yilu; De Pavia, Cintia S.; Pflugfelder, Stephen C.; Shah, Tejas N.; Potma, Eric O.; Brown, Donald J.; Jester, James V.

    2013-01-01

    Purpose Mice exposed to standardized desiccating environmental stress to induce dry eye-like symptoms have been used as a model to study the underlying mechanisms of evaporative dry eye. While studies have shown marked inflammatory and immune changes, the effect of such stress on meibomian gland function remains largely unknown. We sought to evaluate the effects of desiccating stress on meibocyte proliferation and meibum quality. Methods Ten mice were treated with scopolamine and subjected to a drafty low humidity environment (30–35%). Five and ten days after treatment, eyelids were harvested and cryosections stained with Ki67 antibody to identify cycling cells. Sections were also imaged using stimulated Raman scattering (SRS) microscopy to characterize the gland compositional changes by detecting the vibrational signatures of methylene (lipid) and amide-I (protein). Results Desiccating stress caused a 3-fold increase in basal acinar cell proliferation from 18.3 ± 11.1% in untreated mice to 64.4 ± 19.9% and 66.6 ± 13.4% after 5 and 10 days exposure, respectively (P < .001). In addition, SRS analysis showed a wider variation in the protein-to-lipid ratio throughout the gland, suggesting alterations in meibocyte differentiation and lipid synthesis. Conclusions These data are consistent with a model that a desiccating environment may have a direct effect on meibomian gland function, leading to a significant increase in basal acinar cell proliferation, abnormal meibocyte differentiation, and altered lipid production. PMID:24439047

  4. Survival of Methanogens During Desiccation: Implications for Life on Mars

    NASA Astrophysics Data System (ADS)

    Kendrick, Michael G.; Kral, Timothy A.

    2006-08-01

    The relatively recent discoveries that liquid water likely existed on the surface of past Mars and that methane currently exists in the martian atmosphere have fueled the possibility of extant or extinct life on Mars. One possible explanation for the existence of the methane would be the presence of methanogens in the subsurface. Methanogens are microorganisms in the domain Archaea that can metabolize molecular hydrogen as an energy source and carbon dioxide as a carbon source and produce methane. One factor of importance is the arid nature of Mars, at least at the surface. If one is to assume that life exists below the surface, then based on the only example of life that we know, liquid water must be present. Realistically, however, that liquid water may be seasonal just as it is at some locations on our home planet. Here we report on research designed to determine how long certain species of methanogens can survive desiccation on a Mars soil simulant, JSC Mars-1. Methanogenic cells were grown on JSC Mars-1, transferred to a desiccator within a Coy anaerobic environmental chamber, and maintained there for varying time periods. Following removal from the desiccator and rehydration, gas chromatographic measurements of methane indicated survival for varying time periods. Methanosarcina barkeri survived desiccation for 10 days, while Methanobacterium formicicum and Methanothermobacter wolfeii were able to survive for 25 days.

  5. Transcriptional response of Saccharomyces cerevisiae to desiccation and rehydration.

    PubMed

    Singh, Jatinder; Kumar, Deept; Ramakrishnan, Naren; Singhal, Vibha; Jervis, Jody; Garst, James F; Slaughter, Stephen M; DeSantis, Andrea M; Potts, Malcolm; Helm, Richard F

    2005-12-01

    A transcriptional analysis of the response of Saccharomyces cerevisiae strain BY4743 to controlled air-drying (desiccation) and subsequent rehydration under minimal glucose conditions was performed. Expression of genes involved in fatty acid oxidation and the glyoxylate cycle was observed to increase during drying and remained in this state during the rehydration phase. When the BY4743 expression profile for the dried sample was compared to that of a commercially prepared dry active yeast, strikingly similar expression changes were observed. The fact that these two samples, dried by different means, possessed very similar transcriptional profiles supports the hypothesis that the response to desiccation is a coordinated event independent of the particular conditions involved in water removal. Similarities between "stationary-phase-essential genes" and those upregulated during desiccation were also noted, suggesting commonalities in different routes to reduced metabolic states. Trends in extracellular and intracellular glucose and trehalose levels suggested that the cells were in a "holding pattern" during the rehydration phase, a concept that was reinforced by cell cycle analyses. Application of a "redescription mining" algorithm suggested that sulfur metabolism is important for cell survival during desiccation and rehydration.

  6. Survival of methanogens during desiccation: implications for life on Mars.

    PubMed

    Kendrick, Michael G; Kral, Timothy A

    2006-08-01

    The relatively recent discoveries that liquid water likely existed on the surface of past Mars and that methane currently exists in the martian atmosphere have fueled the possibility of extant or extinct life on Mars. One possible explanation for the existence of the methane would be the presence of methanogens in the subsurface. Methanogens are microorganisms in the domain Archaea that can metabolize molecular hydrogen as an energy source and carbon dioxide as a carbon source and produce methane. One factor of importance is the arid nature of Mars, at least at the surface. If one is to assume that life exists below the surface, then based on the only example of life that we know, liquid water must be present. Realistically, however, that liquid water may be seasonal just as it is at some locations on our home planet. Here we report on research designed to determine how long certain species of methanogens can survive desiccation on a Mars soil simulant, JSC Mars-1. Methanogenic cells were grown on JSC Mars-1, transferred to a desiccator within a Coy anaerobic environmental chamber, and maintained there for varying time periods. Following removal from the desiccator and rehydration, gas chromatographic measurements of methane indicated survival for varying time periods. Methanosarcina barkeri survived desiccation for 10 days, while Methanobacterium formicicum and Methanothermobacter wolfeii were able to survive for 25 days.

  7. Antioxidant defense during desiccation of the resurrection plant Haberlea rhodopensis.

    PubMed

    Georgieva, Katya; Dagnon, Soleya; Gesheva, Emiliya; Bojilov, Dimitar; Mihailova, Gergana; Doncheva, Snezhana

    2017-05-01

    Maintaining a strong antioxidant system is essential for preventing drought-induced oxidative stress. Thus, in the present study we investigated the role of some non-enzymic and enzymic antioxidants in desiccation tolerance of Haberlea rhodopensis. The effects of high light upon desiccation on antioxidant capacity was estimated by comparing the response of shade and sun plants. The significant enhancement of the antioxidant capacity at 8% RWC corresponded to an enormous increase in flavonoid content. The important role of ascorbate-glutathione cycle in overcoming oxidative stress during drying of H. rhodopensis was established. The antioxidant capacity increased upon dehydration of both shade and sun plants but some differences in non-enzymatic and enzymatic antioxidants were observed. Investigations on the role of polyphenols in desiccation tolerance are scarce. In the present study the polyphenol profiles (fingerprints) of the resurrection plant Haberlea rhodopensis, including all components of the complex are obtained for the first time. It was clarified that the polyphenol complex of H. rhodopensis includes only two types of glycosides - phenylethanoid glucosides and hispidulin 8-C-glucosides. Upon desiccation the polyphenol content increase and the main role of phenylethanoid glucosides in the protection of H. rhodopensis was revealed.

  8. Incomplete cooling down of Saturn's A ring at solar equinox: Implication for seasonal thermal inertia and internal structure of ring particles

    NASA Astrophysics Data System (ADS)

    Morishima, Ryuji; Spilker, Linda; Brooks, Shawn; Deau, Estelle; Pilorz, Stu

    2016-11-01

    At the solar equinox in August 2009, the Composite Infrared Spectrometer (CIRS) onboard Cassini showed the lowest Saturn's ring temperatures ever observed. Detailed radiative transfer models show that the observed equinox temperatures of Saturn's A ring are much higher than model predictions as long as only the flux from Saturn is taken into account. In addition, the post-equinox temperatures are lower than the pre-equinox temperatures at the same absolute solar elevation angle. These facts indicate that the A ring was not completely cooled down at the equinox and that it is possible to give constraints on the size and seasonal thermal inertia of ring particles using seasonal temperature variations around the equinox. We develop a simple seasonal model for ring temperatures and first assume that the internal density and the thermal inertia of a ring particle are uniform with depth. The particle size is estimated to be 1-2 m. The seasonal thermal inertia is found to be 30-50 J m-2 K-1 s-1/2 in the middle A ring whereas it is ∼10 J m-2 K-1 s-1/2 or as low as the diurnal thermal inertia in the inner and outermost regions of the A ring. An additional internal structure model, in which a particle has a high density core surrounded by a fluffy regolith mantle, shows that the core radius relative to the particle radius is about 0.9 for the middle A ring and is much less for the inner and outer regions of the A ring. This means that the radial variation of the internal density of ring particles exists across the A ring. Some mechanisms may be confining dense particles in the middle A ring against viscous diffusion. Alternatively, the (middle) A ring might have recently formed (<108 yr) by destruction of an icy satellite, so that dense particles have not yet diffused over the A ring and regolith mantles of particles have not grown thick. Our model results also indicate that the composition of the core is predominantly water ice, not rock.

  9. [Desiccation tolerance in seeds of Prosopisferox and Pterogyne nitens (Fabaceae)].

    PubMed

    Morandini, Marcelo Nahuel; Giamminola, Eugenia Mabel; de Viana, Marta Leonor

    2013-03-01

    The high number of endemisms and species diversity together with the accelerated biodiversity loss by deforestation, especially in North Western Argentina, points out the need to work on species conservation combining ex situ and in situ strategies. The aim of this work was to study the desiccation tolerance in seeds of P ferox and P nitens for long term ex situ conservation at the Germplasm Bank of Native Species (BGEN) of the National University of Salta (Argentina). The fruits were collected from ten individuals in P ferox at the National Park Los Cardones and from two sites (Orán and Rivadavia) for P nitens. Desiccation tolerance was assessed following previous established methodologies. The moisture content (MC) of the seeds was determined by keeping them in oven at 103 degreeC and weighting the samples at different intervals till constant weight. Germination essays were carried out with two treatments (control and scarification), with different seed MC (fresh, 10-12%, 3-5%) and in desiccated seeds (3-5% MC) stored six months at -20 degreeC. The MC in P ferox seeds was 14.2% and 10% in P nitens, for both populations studied. Percentage germination in P ferox was higher in the scarification treatments (<82%). The difference between treatments increased with the reduction in MC and the storage for six months at -20 degreeC. Fresh seeds of P nitens do not need scarification treatment, but it is required with the reduction in MC and storage. Mean germination percentage of desiccated seeds stored six months at -20 degreeC was similar in both populations and greater than 82%.We concluded that both species are probably orthodox because seeds tolerated desiccation to 3-5% and storage for six months at -20 degree C.

  10. Alternatives to compressor cooling in California climates

    SciTech Connect

    Feustel, H. ); de Almeida, A. . Dept. of Electrical Engineering); Blumstein, C. . Universitywide Energy Research Group)

    1991-01-01

    This review and discussion has been prepared for the California Institute for Energy Efficiency (CIEE) to examine research on alternatives to compressor cooling. The report focuses on strategies for eliminating compressors in California's transition climates -- moderately warm areas located between the cool coastal regions and the hot central regions. Many of these strategies could also help reduce compressor use in hotter climates. Compressor-driven cooling of residences in California's transition climate regions is an undesirable load for California's electric utilities because load factor is poor and usage is typically high during periods of system peak demand. We review a number of alternatives to compressors, including low-energy strategies: evaporative cooling, natural and induced ventilation, reflective coatings, shading with vegetation and improved glazing, thermal storage, and radiative cooling. Also included are two energy-intensive strategies: absorption cooling and desiccant cooling. Our literature survey leads us to conclude that many of these strategies, used either singly or in combination, are technically and economically feasible alternatives to compressor-driven cooling. 78 refs., 8 figs.

  11. Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results

    SciTech Connect

    Truex, Michael J.; Oostrom, Martinus; Strickland, Christopher E.; Johnson, Timothy C.; Johnson, Christian D.; Clayton, Ray E.; Chronister, Glen B.

    2013-09-01

    A field test of desiccation is being conducted as an element of the deep vadose zone treatability test program. Desiccation technology relies on removal of water from a portion of the subsurface such that the resultant low moisture conditions inhibit downward movement of water and dissolved contaminants. Previously, a field test report (Truex et al. 2012a) was prepared describing the active desiccation portion of the test and initial post-desiccation monitoring data. Additional monitoring data have been collected at the field test site during the post-desiccation period and is reported herein along with interpretation with respect to desiccation performance. This is an interim report including about 2 years of post-desiccation monitoring data.

  12. Solar Control design package

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Information used in the evaluation of design of Solar Control's solar heating and cooling system controller and the Solarstat is given. Some of the information includes system performance specifications, design data brochures, and detailed design drawings.

  13. Deep Vadose Zone Treatability Test for the Hanford Central Plateau. Interim Post-Desiccation Monitoring Results, Fiscal Year 2015

    SciTech Connect

    Truex, Michael J.; Strickland, Christopher E.; Oostrom, Martinus; Johnson, Christian D.; Tartakovsky, Guzel D.; Johnson, Timothy C.; Clayton, Ray E.; Chronister, Glen B.

    2015-09-01

    A field test of desiccation is being conducted as an element of the Deep Vadose Zone Treatability Test Program. The active desiccation portion of the test has been completed. Monitoring data have been collected at the field test site during the post-desiccation period and are reported herein. This is an interim data summary report that includes about 4 years of post-desiccation monitoring data. The DOE field test plan proscribes a total of 5 years of post-desiccation monitoring.

  14. Clay with Desiccation Cracks is an Advection Dominated Environment

    NASA Astrophysics Data System (ADS)

    Baram, S.; Kurtzman, D.; Sher, Y.; Ronen, Z.; Dahan, O.

    2012-04-01

    Heavy clay sediments are regarded "safe" from the hydrological point of view due to their low hydraulic conductivities. However, the formation of desiccation cracks in dispersive clays may dramatically change their bulk hydraulic properties. The impact of desiccation cracks on water percolation, dissolved salts and contaminants transport and redox related reactions (microbial ammonium oxidation and denitrification) were investigated in 6 -12 m clay layer near a diary farm waste lagoon. The study implemented unique vadose-zone monitoring systems that enable in-situ measurements of the temporal variation of the sediment's water content along with frequent sampling of the sediment's pore water along the entire vadose zone (> 30 m). Results from four years of continuous measurements showed quick rises in sediment water content following rain events and temporal wastewater overflows. The percolation pattern indicated dominance of preferential flow through a desiccation-cracks network crossing the entire clay sediment layer. High water-propagation velocities (0.4 - 23.6 m h-1) were observed, indicating that the desiccation-crack network remains open and serves as a preferential flow pathway year-round, even at high sediment water content (~0.50 m3 m-3). The rapid percolation bypassed the most bio-geo-active parts of the soil, transporting even highly sorptive contaminants (testosterone and estrogen) in to the deep sections of the vadose zone, accelerating the underlying groundwater contamination. The ammonium and nitrate concentrations in the vadose zone and the high number of nitrifying and denitrifying bacteria (~108 gene copies gdry-sediemt-1, each) found in the sediment indicated that the entire vadose zone is aerated even at high water content conditions (~0.55 m3 m-3). The dissolved salts concentration in the pore-water and the δ2H-H2O and δ18O-H2O values of the pore-water substantially increased with depth (becoming less depleted) in the clay sediment

  15. Desiccation Tolerance in the Moss Polytrichum formosum: Physiological and Fine-structural Changes during Desiccation and Recovery

    PubMed Central

    Proctor, Michael C. F.; Ligrone, Roberto; Duckett, Jeffrey G.

    2007-01-01

    Background and Aims This study explores basic physiological features and time relations of recovery of photosynthetic activity and CO2 uptake following rehydration of a desiccation-tolerant moss in relation to the full temporal sequence of cytological changes associated with recovery to the normal hydrated state. It seeks reconciliation of the apparently conflicting published physiological and cytological evidence on recovery from desiccation in bryophytes. Methods Observations were made of water-stress responses and recovery using infrared gas analysis and modulated chlorophyll fluorescence, and of structural and ultrastructural changes by light and transmission electron microscopy. Key Results Net CO2 uptake fell to zero at approx. 40 % RWC, paralleling the fluorescence parameter ΦPSII at 200 µmol m–2 s–1 PPFD. On re-wetting the moss after 9–18 d desiccation, the initially negative net CO2 uptake became positive 10–30 min after re-wetting, restoring a net carbon balance after approx. 0·3–1 h. The parameter Fv/Fm reached approx. 80 % of its pre-desiccation value within approx. 10 min of re-wetting. In the presence of the protein-synthesis inhibitors chloramphenicol and cycloheximide, recovery of Fv/Fm (and CO2 exchange) proceeded normally in the dark, but declined rapidly in the light. Though initial recovery was rapid, both net CO2 uptake and Fv/Fm required approx. 24 h to recover completely to pre-desiccation values. The fixation protocols produced neither swelling of tissues nor plasmolysis. Thylakoids, grana and mitochondrial cristae remained intact throughout the drying–re-wetting cycle, but there were striking changes in the form of the organelles, especially the chloroplasts, which had prominent lobes and lamellar extensions in the normally hydrated state, but rounded off when desiccated, returning slowly to their normal state within approx. 24 h of re-wetting. Sub-cellular events during desiccation and re-wetting were generally

  16. Biomass production, nutritional and mineral content of desiccation-sensitive and desiccation-tolerant species of sporobolus under multiple irrigation regimes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The development of low-water-input forages of high quality would be useful for expanding or improving the water use efficiency of livestock production in semi-arid and arid regions. In this study, three Sporobolus species, the desiccation tolerant (DT) species, S. stapfianus Gandoger, and two desicc...

  17. Cool & Connected

    EPA Pesticide Factsheets

    The Cool & Connected planning assistance program helps communities develop strategies and an action plan for using broadband to promote environmentally and economically sustainable community development.

  18. Cooling wall

    SciTech Connect

    Nosenko, V.I.

    1995-07-01

    Protecting the shells of blast furnaces is being resolved by installing cast iron cooling plates. The cooling plates become non-operational in three to five years. The problem is that defects occur in manufacturing the cooling plates. With increased volume and intensity of work placed on blast furnaces, heat on the cast iron cooling plates reduces their reliability that limits the interim repair period of blast furnaces. Scientists and engineers from the Ukraine studied this problem for several years, developing a new method of cooling the blast furnace shaft called the cooling wall. Traditional cast iron plates were replaced by a screen of steel tubes, with the area between the tubes filled with fireproof concrete. Before placing the newly developed furnace shaft into operation, considerable work was completed such as theoretical calculations, design, research of temperature fields and tension. Continual testing over many years confirms the value of this research in operating blast furnaces. The cooling wall works with water cooling as well as vapor cooling and is operating in 14 blast furnaces in the Ukraine and two in Russia, and has operated for as long as 14 years.

  19. STANDARDS CONTROLLING AIR EMISSIONS FOR THE SOIL DESICCATION PILOT TEST

    SciTech Connect

    BENECKE MW

    2010-09-08

    This air emissions document supports implementation of the Treatability Test Plan for Soil Desiccation as outlined in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau (DOE/RL-2007-56). Treatability testing supports evaluation of remedial technologies for technetium-99 (Tc-99) contamination in the vadose zone at sites such as the BC Cribs and Trenches. Soil desiccation has been selected as the first technology for testing because it has been recommended as a promising technology in previous Hanford Site technology evaluations and because testing of soil desiccation will provide useful information to enhance evaluation of other technologies, in particular gas-phase remediation technologies. A soil desiccation pilot test (SDPT) will evaluate the desiccation process (e.g., how the targeted interval is dried) and the long-term performance for mitigation of contaminant transport. The SDPT will dry out a moist zone contaminated by Tc-99 and nitrate that has been detected at Well 299-E13-62 (Borehole C5923). This air emissions document applies to the activities to be completed to conduct the SDPT in the 200-BC-1 operable unit located in the 200 East Area of the Hanford Site. Well 299-E13-62 is planned to be used as an injection well. This well is located between and approximately equidistant from cribs 216-B-16, 216-B-17, 216-B-18. and 216-B-19. Nitrogen gas will be pumped at approximately 300 ft{sup 3}/min into the 299-EI3-62 injection well, located approximately 12 m (39 ft) away from extraction well 299-EI3-65. The soil gas extraction rate will be approximately 150 ft{sup 3}/min. The SDPT will be conducted continuously over a period of approximately six months. The purpose of the test is to evaluate soil desiccation as a potential remedy for protecting groundwater. A conceptual depiction is provided in Figure 1. The soil desiccation process will physically dry, or evaporate, some of the water from the moist zone of interest. As such, it is

  20. Transcriptomes of the desiccation-tolerant resurrection plant Craterostigma plantagineum.

    PubMed

    Rodriguez, Maria C Suarez; Edsgärd, Daniel; Hussain, Syed S; Alquezar, David; Rasmussen, Morten; Gilbert, Thomas; Nielsen, Bjørn H; Bartels, Dorothea; Mundy, John

    2010-07-01

    Studies of the resurrection plant Craterostigma plantagineum have revealed some of the mechanisms which these desiccation-tolerant plants use to survive environments with extreme dehydration and restricted seasonal water. Most resurrection plants are polyploid with large genomes, which has hindered efforts to obtain whole genome sequences and perform mutational analysis. However, the application of deep sequencing technologies to transcriptomics now permits large-scale analyses of gene expression patterns despite the lack of a reference genome. Here we use pyro-sequencing to characterize the transcriptomes of C. plantagineum leaves at four stages of dehydration and rehydration. This reveals that genes involved in several pathways, such as those required for vitamin K and thiamin biosynthesis, are tightly regulated at the level of gene expression. Our analysis also provides a comprehensive picture of the array of cellular responses controlled by gene expression that allow resurrection plants to survive desiccation.

  1. X-ray crystal structures of a severely desiccated protein.

    PubMed Central

    Bell, J. A.

    1999-01-01

    Unlike most protein crystals, form IX of bovine pancreatic ribonuclease A diffracts well when severely dehydrated. Crystal structures have been solved after 2.5 and 4 days of desiccation with CaSO4, at 1.9 and 2.0 A resolution, respectively. The two desiccated structures are very similar. An RMS displacement of 1.6 A is observed for main-chain atoms in each structure when compared to the hydrated crystal structure with some large rearrangements observed in loop regions. The structural changes are the result of intermolecular contacts formed by strong electrostatic interactions in the absence of a high dielectric medium. The electron density is very diffuse for some surface loops, consistent with a very disordered structure. This disorder is related to the conformational changes. These results help explain conformational changes during the lyophilization of protein and the associated phenomena of denaturation and molecular memory. PMID:10548049

  2. Reversible Inactivation and Desiccation Tolerance of Silicified Viruses

    SciTech Connect

    Laidler, James J.; Shugart, Jessica A.; Cady, Sherry L.; Bahjat, Keith S.; Stedman, Kenneth M.

    2013-11-19

    Long-distance host-independent virus dispersal is poorly understood, especially for viruses found in isolated ecosystems. To demonstrate a possible dispersal mechanism, we show that bacteriophage T4, archaeal virus SSV-K and Vaccinia are reversibly inactivated by mineralization in silica under conditions similar to volcanic hot springs. By contrast, bacteriophage PRD1 is not silicified. Moreover silicification provides viruses with remarkable desiccation resistance, which could allow extensive aerial dispersal.

  3. Development and Analysis of Desiccant Enhanced Evaporative Air Conditioner Prototype

    SciTech Connect

    Kozubal, E.; Woods, J.; Judkoff, R.

    2012-04-01

    This report documents the design of a desiccant enhanced evaporative air conditioner (DEVAP AC) prototype and the testing to prove its performance. Previous numerical modeling and building energy simulations indicate a DEVAP AC can save significant energy compared to a conventional vapor compression AC (Kozubal et al. 2011). The purposes of this research were to build DEVAP prototypes, test them to validate the numerical model, and identify potential commercialization barriers.

  4. Triiodothyronine and thyroxine content of desiccated thyroid tablets.

    PubMed

    Rees-Jones, R W; Larsen, P R

    1977-11-01

    Triiodothyronine (T3) and thyroxine (T4) were measured by radioimmunoassay in Pronase hydrolysates of four lots each of 1- and 2-grain tablets of desiccated thyroid (Thyroid, Armour) and thyroglobulin (Proloid, Warner-Chilcott). The methodology used was verified by studies of tablets containing known quantities of T4 and T3. One grain of desiccated thyroid contained 12 +/- 1 and 64 +/- 3 microgram (mean +/- SD) of T3 and T4 per tablet, respectively (T4/T3 molar ratio, 4.3). A 1-grain tablet of thyroglobulin contained 16 +/- 2 and 55 +/- 5 microgram of T3 and T4, respectively with a T4/T3 ratio of 2.9. Two-grain tablets generally contained twice the quantity of T3 and T4 in the 1-grain preparations. The variation in T3 and T4 content between the four lots of each tablet strength for each product was 10% or less. These estimates of T3 and T4 content are 1.5- to 2-fold greater than those previously published. This difference probably results from the more sophisticated methodology now available which does not require chromatographic separation of T3 and T4 or iodometry. Using calculations based on published estimates of T4 and T3 absorption and of the T3/T4 potency ratio, it would appear that the T3 content of desiccated thyroid and thyroglobulin provide approximately 39% and 51%, respectively, of the thyromimetic activity of these two medications.

  5. Cool Shelter

    ERIC Educational Resources Information Center

    Praeger, Charles E.

    2005-01-01

    Amid climbing energy costs and tightening budgets, administrators at school districts, colleges and universities are looking for all avenues of potential savings while promoting sustainable communities. Cool metal roofing can save schools money and promote sustainable design at the same time. Cool metal roofing keeps the sun's heat from collecting…

  6. Comparative metabolic profiling between desiccation-sensitive and desiccation-tolerant species of Selaginella reveals insights into the resurrection trait.

    PubMed

    Yobi, Abou; Wone, Bernard W M; Xu, Wenxin; Alexander, Danny C; Guo, Lining; Ryals, John A; Oliver, Melvin J; Cushman, John C

    2012-12-01

    Spike mosses (Selaginellaceae) represent an ancient lineage of vascular plants in which some species have evolved desiccation tolerance (DT). A sister-group contrast to reveal the metabolic basis of DT was conducted between a desiccation-tolerant species, Selaginella lepidophylla, and a desiccation-sensitive species, Selaginella moellendorffii, at 100% relative water content (RWC) and 50% RWC using non-biased, global metabolomics profiling technology, based on GC/MS and UHLC/MS/MS(2) platforms. A total of 301 metabolites, including 170 named (56.5%) and 131 (43.5%) unnamed compounds, were characterized across both species. S.  lepidophylla retained significantly higher abundances of sucrose, mono- and polysaccharides, and sugar alcohols than did S. moellendorffii. Aromatic amino acids, the well-known osmoprotectant betaine and flavonoids were also more abundant in S. lepidophylla. Notably, levels of γ-glutamyl amino acid, linked with glutathione metabolism in the detoxification of reactive oxygen species, and with possible nitrogen remobilization following rehydration, were markedly higher in S. lepidophylla. Markers for lipoxygenase activity were also greater in S. lepidophylla, especially at 50% RWC. S. moellendorffii contained more than twice the number of unnamed compounds, with only a slightly greater abundance than in S. lepidophylla. In contrast, S. lepidophylla contained 14 unnamed compounds of fivefold or greater abundance than in S. moellendorffii, suggesting that these compounds might play critical roles in DT. Overall, S. lepidophylla appears poised to tolerate desiccation in a constitutive manner using a wide range of metabolites with some inducible components, whereas S. moellendorffii mounts only limited metabolic responses to dehydration stress.

  7. An Experimental Evolution Test of the Relationship between Melanism and Desiccation Survival in Insects

    PubMed Central

    Rajpurohit, Subhash; Peterson, Lisa Marie; Orr, Andrew J.; Marlon, Anthony J.; Gibbs, Allen G.

    2016-01-01

    We used experimental evolution to test the ‘melanism-desiccation’ hypothesis, which proposes that dark cuticle in several Drosophila species is an adaptation for increased desiccation tolerance. We selected for dark and light body pigmentation in replicated populations of D. melanogaster and assayed several traits related to water balance. We also scored pigmentation and desiccation tolerance in populations selected for desiccation survival. Populations in both selection regimes showed large differences in the traits directly under selection. However, after over 40 generations of pigmentation selection, dark-selected populations were not more desiccation-tolerant than light-selected and control populations, nor did we find significant changes in mass or carbohydrate amounts that could affect desiccation resistance. Body pigmentation of desiccation-selected populations did not differ from control populations after over 140 generations of selection, although selected populations lost water less rapidly. Our results do not support an important role for melanization in Drosophila water balance. PMID:27658246

  8. Photosynthesis in desiccation tolerant plants: energy metabolism and antioxidative stress defense.

    PubMed

    Dinakar, Challabathula; Djilianov, Dimitar; Bartels, Dorothea

    2012-01-01

    Resurrection plants are regarded as excellent models to study the mechanisms associated with desiccation tolerance. During the past years tremendous progress has been made in understanding the phenomenon of desiccation tolerance in resurrection plants, but many questions are open concerning the mechanisms enabling these plants to survive desiccation. The photosynthetic apparatus is very sensitive to reactive oxygen species mediated injury during desiccation and must be maintained or quickly repaired upon rehydration. The photosynthetic apparatus is a primary source of generating reactive oxygen species. The unique ability of plants to withstand the oxidative stress imposed by reactive oxygen species during desiccation depends on the production of antioxidants. The present review considers the overall strategies and the mechanisms involved in the desiccation tolerance in the first part and will focus on the effects on photosynthesis, energy metabolism and antioxidative stress defenses in the second part.

  9. Salinity effects on the dynamics and patterns of desiccation cracks

    NASA Astrophysics Data System (ADS)

    Shokri, N.; Zhou, P.

    2012-12-01

    Cracking arising from desiccation is a ubiquitous phenomenon encountered in various industrial and geo-environmental applications including drying of clayey soil, cement, ceramics, gels, and many more colloidal suspensions. Presence of cracks in muddy sediments modifies the characteristics of the medium such as pore structure, porosity, and permeability which in turn influence various flow and transport processes. Thus it remains a topic of great interest in many disciplines to describe the dynamics of desiccation cracking under various boundary conditions. To this end, we conducted a comprehensive study to investigate effects of NaCl concentrations on cracking dynamics and patterns during desiccation of Bentonite. Mixtures of Bentonite and NaCl solutions were prepared with NaCl concentration varying from 2 to 10 percent in 0.5 percent increment (totally 17 configurations). The slurry was placed in a Petri dish mounted on a digital balance to record the evaporation dynamics. The atmospheric conditions were kept constant using an environmental chamber. An automatic camera was used to record the dynamics of macro-cracks (mm scale) at the surface of desiccating clay each minute. The obtained results illustrate the significant effects of salt concentration on the initiation, propagation, morphology and general dynamics of macro-cracks. We found that higher salt concentrations results in larger macro cracks' lengths attributed to the effects of NaCl on compressing the electric double layer of particles at increasing electrolyte concentrations which reduce considerably the repulsive forces among the particles and causing instability of the slurry and flocculation of the colloidal particles. Rheological measurements by means of a stress controlled rheometer revealed that the yield stress of the slurry decreases as NaCl concentration increases which may indicate aggregation of larger units in the slurry as a result of flocculation causing larger cracks' lengths due to

  10. Desiccation resistance and contamination as mechanisms of gaia.

    PubMed

    Brown, S; Margulis, L; Ibarra, S; Siqueiros, D

    1985-01-01

    The gaia hypothesis, formulated by J.E. Lovelock, asserts the composition of the reactive gases, the oxidation-reduction state and the temperature of the lower atmosphere of the planet Earth are actively regulated by the biota. Lovelock and Watson, using highly simplified mathematical models, have shown that the modulation of atmospheric temperature can be achieved by exponentially growing populations of differently colored organisms ("dark and light daisies"). It is more likely that the modulation of atmospheric gas composition is based on the colligative properties of exponentially growing mixed populations of microorganisms rather than on "daisies". Exponential growth of one population of microorganisms leads to gaseous and other metabolic products released to the environment, which favor the exponential growth of different populations, each with their own unique emissions. Extremely high densities of mixed populations of microorganisms ensue. These populations form structured microbial communities composed of members in varying states of activity. Growth potential of metabolically diverse populations most likely provides the basis for the responsiveness of the biota to changing environments. We have attempted to measure an aspect of the growth potential and diversity of one microbial community, that from a flat laminated microbial mat dominated by the cyanobacterium, Microcoleus. Microbial mat samples collected at yearly intervals between 1977 and 1982 were allowed to dry. Subsamples were revived under laboratory conditions by rewetting, and the resulting complex microbial populations were analyzed. Greater than 10(4) viable organisms per ml were estimated to be present in the desiccated samples. Only a portion of the diverse community could be characterized. There were at least 115 different types of desiccation resistant microorganisms present in these samples, primarily bacteria. However, more than a dozen types of rather uncommon fungi and protoctists were

  11. Method and composition for molding low density desiccant syntactic foam articles

    DOEpatents

    Lula, James W.; Schicker, James R.

    1984-01-01

    A method and a composition are provided for molding low density desiccant syntactic foam articles. A low density molded desiccant article may be made as a syntactic foam by blending a thermosetting resin, microspheres and molecular sieve desiccant powder, molding and curing. Such articles have densities of 0.2-0.9 g/cc, moisture capacities of 1-12% by weight, and can serve as light weight structural supports.

  12. Electron Cooling

    NASA Astrophysics Data System (ADS)

    Ellison, Timothy J. P.

    1991-08-01

    Electron cooling is a method of reducing the 6 -dimensional phase space volume of a stored ion beam. The technique was invented by Budker and first developed by him and his colleagues at the Institute for Nuclear Physics in Novosibirsk. Further studies of electron cooling were subsequently performed at CERN and Fermilab. At the Indiana University Cyclotron Facility (IUCF) an electron cooling system was designed, built, and commissioned in 1988. This was the highest energy system built to date (270 keV for cooling 500 MeV protons) and the first such system to be used as an instrument for performing nuclear and atomic physics experiments. This dissertation summarizes the design principles; measurements of the longitudinal drag rate (cooling force), equilibrium cooled beam properties and effective longitudinal electron beam temperature. These measurements are compared with theory and with the measured performance of other cooling systems. In addition the feasibility of extending this technology to energies an order of magnitude higher are discussed.

  13. Effect of nitrogen starvation on desiccation tolerance of Arctic Microcoleus strains (cyanobacteria)

    PubMed Central

    Tashyreva, Daria; Elster, Josef

    2015-01-01

    Although desiccation tolerance of Microcoleus species is a well-known phenomenon, there is very little information about their limits of desiccation tolerance in terms of cellular water content, the survival rate of their cells, and the environmental factors inducing their resistance to drying. We have discovered that three Microcoleus strains, isolated from terrestrial habitats of the High Arctic, survived extensive dehydration (to 0.23 g water g-1 dry mass), but did not tolerate complete desiccation (to 0.03 g water g-1 dry mass) regardless of pre-desiccation treatments. However, these treatments were critical for the survival of incomplete desiccation: cultures grown under optimal conditions failed to survive even incomplete desiccation; a low temperature enabled only 0–15% of cells to survive, while 39.8–65.9% of cells remained alive and intact after nitrogen starvation. Unlike Nostoc, which co-exists with Microcoleus in Arctic terrestrial habitats, Microcoleus strains are not truly anhydrobiotic and do not possess constitutive desiccation tolerance. Instead, it seems that the survival strategy of Microcoleus in periodically dry habitats involves avoidance of complete desiccation, but tolerance to milder desiccation stress, which is induced by suboptimal conditions (e.g., nitrogen starvation). PMID:25904909

  14. Desiccation-induced physiological and biochemical changes in resurrection plant, Selaginella bryopteris.

    PubMed

    Pandey, Vivek; Ranjan, Sanjay; Deeba, Farah; Pandey, Ashutosh K; Singh, Ruchi; Shirke, Pramod A; Pathre, Uday V

    2010-11-01

    Selaginella bryopteris is a lycophyte resurrection plant, which incurves during desiccation and recovers on availability of moisture. The aim of the study was to test and understand the various physiological and biochemical changes the fronds undergo during desiccation and rehydration, to get an insight as to how this plant adapts and survives through the dry phase. Upon desiccation, S. bryopteris fronds showed drastic inhibition in net photosynthesis (A) and maximal photochemical efficiency of PSII (F(v)/F(m)) however, chlorophyll content did not show much variation. Dark respiration (R(d)) continued even at 10% relative water content (RWC), and showed a burst after rehydration, which is proposed to be crucial to establish protection mechanisms. Desiccation caused an enhanced production of reactive oxygen species (ROS) and increased lipid peroxidation. Proline accumulation increased substantially by 11-fold. Sucrose and starch contents decreased upon desiccation as compared to control. The antioxidative enzymes viz. superoxide dismutase (SOD), ascorbate peroxidase (APX) and catalase (CAT) along with soluble acid invertase increased during desiccation. S. bryopteris shows mechanical as well as physiological mechanisms for tolerance to extreme levels of desiccation stress. The rapid and almost complete recovery of F(v)/F(m) after rehydration clearly indicates the absence of marked photoinhibitory or thermal injury to PSII during desiccation. This along with the homoiochlorophyllous characteristics enables S. bryopteris to recover its A. The antioxidant metabolism further plays an important role in the desiccation tolerance of S. bryopteris.

  15. Colorado State University Program for developing, testing, evaluating and optimizing solar heating and cooling systems. Project status report, August--September 1994

    SciTech Connect

    Hittle, D.C.

    1994-11-01

    The current work has been to validate Florida Solar Energy Center`s models of the Solahart 302K and 302K-AS systems to prepare a rating for the Sacramento Municipal Utility District`s rebate program for solar domestic hot water heaters.

  16. Cooled railplug

    DOEpatents

    Weldon, William F.

    1996-01-01

    The railplug is a plasma ignitor capable of injecting a high energy plasma jet into a combustion chamber of an internal combustion engine or continuous combustion system. An improved railplug is provided which has dual coaxial chambers (either internal or external to the center electrode) that provide for forced convective cooling of the electrodes using the normal pressure changes occurring in an internal combustion engine. This convective cooling reduces the temperature of the hot spot associated with the plasma initiation point, particularly in coaxial railplug configurations, and extends the useful life of the railplug. The convective cooling technique may also be employed in a railplug having parallel dual rails using dual, coaxial chambers.

  17. The physiological links of the increased photosystem II activity in moderately desiccated Porphyra haitanensis (Bangiales, Rhodophyta) to the cyclic electron flow during desiccation and re-hydration.

    PubMed

    Gao, Shan; Niu, Jianfeng; Chen, Weizhou; Wang, Guangce; Xie, Xiujun; Pan, Guanghua; Gu, Wenhui; Zhu, Daling

    2013-09-01

    Photosynthetic electron flow changed considerably during desiccation and re-hydration of the intertidal macroalgae Porphyra haitanensis. Activities of both photosystem (PSI) and photosystem (PSII) increased significantly at moderate desiccation levels. Whereas PSII activity was abolished at an absolute water content (AWC) <24 %, PSI remained active with progressive decreases in AWC to values as low as 16 %. This result suggested that cyclic electron flow around PSI was still active after inactivation of linear electron flow following severe desiccation. Moreover, the PSI activity was restored more rapidly than that of PSII upon re-hydration. Pretreatment of the blades with 3-(3',4'-dichlorophenyl)-1,1-dimethylurea (DCMU) suppressed PSII activity following desiccation to an AWC of ~16 % AWC. Cyclic electron flow around PSI decreased markedly in blades pretreated with DCMU than in blades without pretreatment of DCMU during re-hydration in seawater containing DCMU. All results suggested that the activity of PSII under desiccation conditions plays an important role in the operation of cyclic electron flow during desiccation and its recovery during re-hydration. Therefore, we proposed the PSII activity during desiccation could eventually lead to the accumulation of NADPH, which could serve as electron donor for P700(+) and promote its recovery during re-hydration, thereby favoring the operation of cyclic electron flow.

  18. Cool Vest

    NASA Technical Reports Server (NTRS)

    1982-01-01

    ILC, Dover Division's lightweight cooling garment, called Cool Vest was designed to eliminate the harmful effects of heat stress; increases tolerance time in hot environments by almost 300 percent. Made of urethane-coated nylon used in Apollo, it works to keep the body cool, circulating chilled water throughout the lining by means of a small battery-powered pump. A pocket houses the pump, battery and the coolant which can be ice or a frozen gel, a valve control allows temperature regulation. One version is self-contained and portable for unrestrained movement, another has an umbilical line attached to an external source of coolant, such as standard tap water, when extended mobility is not required. It is reported from customers that the Cool Vest pays for itself in increased productivity in very high temperatures.

  19. Desiccation tolerance of iron bacteria biofilms on Mars regolith simulants

    NASA Astrophysics Data System (ADS)

    Feyh, Nina; Szewzyk, Ulrich

    2010-05-01

    Iron oxidizing bacteria play an important role in the geological redox cycling of iron on earth. The redox change between Fe(II) and Fe(III) can be used for biological energy production [1]. Therefore iron oxidation in the iron rich martian soils may be or may have been microbially mediated. The microbial conversion of iron is considered to be an ancient form of metabolism [2], so it might have evolved on Mars as well. However, to exist in recent martian soils, bacteria must be able to endure dry and cold conditions. Neutrophilic iron oxidizers can be found in various iron rich aquatic environments, where they lead to the precipitation of insoluble ferric hydroxides. Some of these environments fall temporarily dry, what could have led to an adaptation to desiccation by bacteria, existing there. One strategy of iron bacteria to endure drought stress might be the formation of biofilms by excreting Extracellular Polymeric Substances (EPS). The deposition of iron hydroxides could enable them to endure dry conditions as well. For our experiments, neutrophilic iron oxidizing bacteria have been isolated from a creek in Bad Salzhausen/Hesse and temporarily drying out pools in Tierra del Fuego. Strains from aquatic environments in the national park "Unteres Odertal" and from water wells in Berlin/Brandenburg are included in the tests as well. In desiccation experiments, the capability of iron bacteria to tolerate dry conditions are investigated. The aim of our first experiment is the adaptation to dry conditions. Biofilms of 15 strains are grown on ceramic beads in liquid medium containing complexed Fe(II), established biofilms contain Fe(III) precipitates. The cultures are desiccated in a sterile airflow until the weight of the cultures remained constant. After a desiccation period of 9 h up to 7 d, the beads are transferred to fresh liquid medium. Adapted strains are used in further desiccation experiments, where biofilms are grown on two martian regolith simulants. These

  20. Salinity Effects on Cracking Morphology and Dynamics in Desiccating Clays

    NASA Astrophysics Data System (ADS)

    DeCarlo, K.; Shokri, N.

    2013-12-01

    Saline conditions induce not only chemical but physical changes in swelling clays, and have a significant influence on the crack dynamics in desiccating clays. In this study, we used X-ray computerized tomography (CT) to experimentally investigate the effects of sodium chloride on the morphology and dynamics of desiccation cracks in three-dimensional mixtures of sand-bentonite slurry under varying rheological conditions. Rectangular glass containers (40.5x40.5x56 mm^3) were packed with sand-bentonite slurries of different salt concentrations, with the top boundary exposed to air for evaporation. The growth and propagation of the cracking network that subsequently formed was visualized in 3D at multiple intervals. 3D characterization of cracking dynamics shows a high extent of localized superficial crack networks at low salinity, with a transition to less extensive but deeper, more centralized crack networks with increased salinity. The observed behavior was described in the context of rheological and colloidal properties of the clay, which suggest the transition from a voluminous and poorly-sorted stacked clay structure to a more compact and highly cohesive entangled clay structure as salt concentration increases in the evaporating samples. This is further corroborated by vertical profiles of sample water distribution, which shows localized uniform drying at the higher salt concentrations. Our results provide new insights regarding the formation, patterns, dynamics and characteristics of desiccation cracks formed during evaporation from 3D saline clay structures, which will be useful in various hydrological applications including water management, land surface evaporation, and subsurface contaminant transport.

  1. Enzymes and Metabolites in Carbohydrate Metabolism of Desiccation Tolerant Plants.

    PubMed

    Zhang, Qingwei; Song, Xiaomin; Bartels, Dorothea

    2016-12-15

    Resurrection plants can tolerate extreme water loss. Substantial sugar accumulation is a phenomenon in resurrection plants during dehydration. Sugars have been identified as one important factor contributing to desiccation tolerance. Phylogenetic diversity of resurrection plants reflects the diversity of sugar metabolism in response to dehydration. Sugars, which accumulate during dehydration, have been shown to protect macromolecules and membranes and to scavenge reactive oxygen species. This review focuses on the performance of enzymes participating in sugar metabolism during dehydration stress. The relation between sugar metabolism and other biochemical activities is discussed and open questions as well as potential experimental approaches are proposed.

  2. Enzymes and Metabolites in Carbohydrate Metabolism of Desiccation Tolerant Plants

    PubMed Central

    Zhang, Qingwei; Song, Xiaomin; Bartels, Dorothea

    2016-01-01

    Resurrection plants can tolerate extreme water loss. Substantial sugar accumulation is a phenomenon in resurrection plants during dehydration. Sugars have been identified as one important factor contributing to desiccation tolerance. Phylogenetic diversity of resurrection plants reflects the diversity of sugar metabolism in response to dehydration. Sugars, which accumulate during dehydration, have been shown to protect macromolecules and membranes and to scavenge reactive oxygen species. This review focuses on the performance of enzymes participating in sugar metabolism during dehydration stress. The relation between sugar metabolism and other biochemical activities is discussed and open questions as well as potential experimental approaches are proposed. PMID:28248249

  3. Color-preserving daytime radiative cooling

    NASA Astrophysics Data System (ADS)

    Zhu, Linxiao; Raman, Aaswath; Fan, Shanhui

    2013-11-01

    We introduce a general approach to radiatively lower the temperature of a structure, while preserving its color under sunlight. The cooling effect persists in the presence of considerable convective and conductive heat exchange and for different solar absorptances.

  4. Color-preserving daytime radiative cooling

    SciTech Connect

    Zhu, Linxiao; Raman, Aaswath; Fan, Shanhui

    2013-11-25

    We introduce a general approach to radiatively lower the temperature of a structure, while preserving its color under sunlight. The cooling effect persists in the presence of considerable convective and conductive heat exchange and for different solar absorptances.

  5. The use of plant stress biomarkers in assessing the effects of desiccation in zygotic embryos from recalcitrant seeds: challenges and considerations.

    PubMed

    Sershen; Varghese, B; Naidoo, C; Pammenter, N W

    2016-05-01

    Zygotic embryos from recalcitrant seeds are sensitive to desiccation. In spite of their sensitivity, rapid partial dehydration is necessary for their successful cryopreservation. However, dehydration to water contents (WCs) that preclude lethal ice crystal formation during cooling and rewarming generally leads to desiccation damage. This study investigated the effects of rapid dehydration on selected stress biomarkers (electrolyte leakage, respiratory competence, rate of protein synthesis, superoxide production, lipid peroxidation, antioxidant activity and degree of cellular vacuolation) in zygotic embryos of four recalcitrant-seeded species. Most biomarkers indicated differences in the levels of stress/damage incurred by embryos dried to WCs < and >0.4 g·g(-1) , within species; however, these changes were often unrelated to viability and percentage water loss when data for the four species were pooled for regression analyses. Dehydration-induced electrolyte leakage was, however, positively related with percentage water loss, while biomarkers of cellular vacuolation were positively related with both percentage water loss and viability. This suggests that electrolyte leakage and degree of cellular vacuolation can be used to quantify dehydration-induced stress/damage. Biomarkers such as superoxide production, whilst useful in establishing the nature of the dehydration stress incurred may not be able to distinguish the effects of different WCs/drying times. Irrespective of which biomarker is used, the data suggest that understanding differences in desiccation sensitivity across recalcitrant-seeded species will remain a challenge unless these biomarkers are related to a generic desiccation stress index that integrates the effects of percentage water loss and drying time.

  6. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 2. Conceptual design, Sections 5 and 6

    SciTech Connect

    1980-01-01

    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume contains the detailed conceptual design and cost/performance estimates and an assessment of the commercial scale solar central receiver hybrid power system. (WHK)

  7. The competence to acquire cellular desiccation tolerance is independent of seed morphological development.

    PubMed

    Golovina, E A; Hoekstra, F A; Van Aelst, A C

    2001-05-01

    Acquisition of desiccation tolerance and the related changes at the cellular level in wheat (Triticum aestivum cv. Priokskaya) kernels during normal development and premature drying on the ear were studied using a spin probe technique and low temperature scanning electron microscopy. During normal development, the ability of embryos to germinate after rapid drying and rehydration was acquired after completion of morphological development, which is a few days before mass maturity. The acquisition of desiccation tolerance, as assessed by germination, was associated with an upsurge in cytoplasmic viscosity, the onset of accumulation of protein and oil bodies, and the retention of membrane integrity upon dehydration/rehydration. These features were also used to assess cellular desiccation tolerance in the cases when germination could not occur. Slow premature drying was used to decouple the acquisition of cellular desiccation tolerance from morphogenesis. Upon premature drying of kernels on the ears of plants cut at 5 d after anthesis, desiccation-tolerant dwarf embryos were formed that were able to germinate. When plants were cut at earlier stages poorly developed embryos were formed that were unable to germinate, but cellular desiccation tolerance was nevertheless acquired. In such prematurely dried kernels, peripheral meristematic endosperm cells had already passed through similar physiological and ultrastructural changes associated with the acquisition of cellular desiccation tolerance. It is concluded that despite the apparent strong integration in seed development, desiccation tolerance can be acquired by the meristematic cells in the developing embryo and cambial layer of endosperm, independently of morphological development.

  8. Rapid desiccation hardening changes the cuticular hydrocarbon profile of Drosophila melanogaster.

    PubMed

    Stinziano, Joseph R; Sové, Richard J; Rundle, Howard D; Sinclair, Brent J

    2015-02-01

    The success of insects in terrestrial environments is due in large part to their ability to resist desiccation stress. Since the majority of water is lost across the cuticle, a relatively water-impermeable cuticle is a major component of insect desiccation resistance. Cuticular permeability is affected by the properties and mixing effects of component hydrocarbons, and changes in cuticular hydrocarbons can affect desiccation tolerance. A pre-exposure to a mild desiccation stress increases duration of desiccation survival in adult female Drosophila melanogaster, via a decrease in cuticular permeability. To test whether this acute response to desiccation stress is due to a change in cuticular hydrocarbons, we treated male and female D. melanogaster to a rapid desiccation hardening (RDH) treatment and used gas chromatography to examine the effects on cuticular hydrocarbon composition. RDH led to reduced proportions of unsaturated and methylated hydrocarbons compared to controls in females, but although RDH modified the cuticular hydrocarbon profile in males, there was no coordinated pattern. These data suggest that the phenomenon of RDH leading to reduced cuticular water loss occurs via an acute change in cuticular hydrocarbons that enhances desiccation tolerance in female, but not male, D. melanogaster.

  9. Antioxidant defences in hydrated and desiccated states of the tardigrade Paramacrobiotus richtersi.

    PubMed

    Rizzo, Angela M; Negroni, Manuela; Altiero, Tiziana; Montorfano, Gigliola; Corsetto, Paola; Berselli, Patrizia; Berra, Bruno; Guidetti, Roberto; Rebecchi, Lorena

    2010-06-01

    Reactive oxygen species (ROS) are formed in all aerobic organisms, potentially leading to oxidative damage of all biological molecules. A number of defence mechanisms have developed to protect the organism from attack by ROS. Desiccation tolerance is correlated with an increase in the antioxidant potential in several organisms, but the regulation of the antioxidant defence system is complex and its role in desiccation-tolerant organisms is not yet firmly established. To determine if anhydrobiotic tardigrades have an antioxidant defence system, capable of counteracting ROS, we compared the activity of several antioxidant enzymes, the fatty acid composition and Heat shock protein expression in two physiological states (desiccated vs. hydrated) of the tardigrade Paramacrobiotus richtersi. In hydrated tardigrades, superoxide dismutase and catalase show comparable activities, while in desiccated specimens the activity of superoxide dismutase increases. Both glutathione peroxidase and glutathione were induced by desiccation. The percentage of fatty acid composition of polyunsaturated fatty acids and the amount of thiobarbituric acid reactive substances are higher in desiccated animals than in hydrated ones. Lastly, desiccated tardigrades did not differ significantly from the hydrated ones in the relative levels of Hsp70 and Hsp90. These results indicate that the possession of antioxidant metabolism could represent a crucial strategy to avoid damages during desiccation in anhydrobiotic tardigrades.

  10. A sister group metabolomic contrast delineates the biochemical regulation underlying desiccation tolerance in Sporobolus stapfianus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Understanding how plant cells tolerate dehydration is a vital prerequisite for developing strategies for improving drought tolerance. The desiccation tolerant grass Sporobolus stapfianus and the desiccation sensitive S. pyramidalis were used to form a sister-group contrast to reveal adaptive metabo...

  11. Key genes involved in desiccation tolerance and dormancy across life forms

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The ability to survive desiccation is widespread in seeds, whereas it is rare in vegetative tissues of adult flowering plants. Some genetic traits conserved among desiccation-tolerant seeds and resurrection plants have been detected but more molecular aspects need to be revealed to formulate hypothe...

  12. Proteomic profiling and redox status alteration of recalcitrant tea (Camellia sinensis) seed in response to desiccation.

    PubMed

    Chen, Qi; Yang, Liming; Ahmad, Parvaiz; Wan, Xiaochun; Hu, Xiangyang

    2011-03-01

    Tea seed is believed to be recalcitrant based on its sensitivity to chilling or drying stress. Reactive oxygen species (ROS) and alterations in cytosolic redox status have been implicated in intolerance to desiccation by recalcitrant seed, but there is little information available regarding how ROS are regulated in seeds susceptible to drying stress. We investigated changes in protein expression and activity in tea embryo in response to desiccation using physiological and proteomic methods. Results showed that desiccation treatment dramatically induced the accumulation of H(2)O(2) in tea embryos, accompanied by increased activities of antioxidant enzymes like ascorbate peroxidase (APX) and superoxide dismutase (SOD). Proteomic analyses also demonstrated that 23 proteins associated with defense response, metabolism and redox status were up-regulated following desiccation. Increase in antioxidants, ascorbic acid (AsA) and catalase (CAT) (H(2)O(2) scavengers) partially assuaged desiccation damage to tea seed, resulting in improved germination rates. Higher accumulation of H(2)O(2) aggravated desiccation damage to seeds leading to lower germination activity. We propose that desiccation causes an over-accumulation of ROS that are not efficiently scavenged by increased levels of antioxidant enzymes. High levels of ROS alter the redox status and are detrimental to seed viability. Reducing ROS to appropriate concentrations is an efficient way to reduce desiccation damage and improve germination rates of recalcitrant seeds.

  13. The structure of the desiccated Richtersius coronifer (Richters, 1903).

    PubMed

    Czerneková, Michaela; Jönsson, K Ingemar; Chajec, Lukasz; Student, Sebastian; Poprawa, Izabela

    2017-05-01

    Tun formation is an essential morphological adaptation for entering the anhydrobiotic state in tardigrades, but its internal structure has rarely been investigated. We present the structure and ultrastructure of organs and cells in desiccated Richtersius coronifer by transmission and scanning electron microscopy, confocal microscopy, and histochemical methods. A 3D reconstruction of the body organization of the tun stage is also presented. The tun formation during anhydrobiosis of tardigrades is a process of anterior-posterior body contraction, which relocates some organs such as the pharyngeal bulb. The cuticle is composed of epicuticle, intracuticle and procuticle; flocculent coat; and trilaminate layer. Moulting does not seem to restrict the tun formation, as evidenced from tardigrade tuns that were in the process of moulting. The storage cells of desiccated specimens filled up the free inner space and surrounded internal organs, such as the ovary and digestive system, which were contracted. All cells (epidermal cells, storage cells, ovary cells, cells of the digestive system) underwent shrinkage, and their cytoplasm was electron dense. Lipids and polysaccharides dominated among reserve material of storage cells, while the amount of protein was small. The basic morphology of specific cell types and organelles did not differ between active and anhydrobiotic R. coronifer.

  14. Cooling Vest

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Because quadriplegics are unable to perspire below the level of spinal injury, they cannot tolerate heat stress. A cooling vest developed by Ames Research Center and Upjohn Company allows them to participate in outdoor activities. The vest is an adaptation of Ames technology for thermal control garments used to remove excess body heat of astronauts. The vest consists of a series of corrugated channels through which cooled water circulates. Its two outer layers are urethane coated nylon, and there is an inner layer which incorporates the corrugated channels. It can be worn as a backpack or affixed to a wheelchair. The unit includes a rechargeable battery, mini-pump, two quart reservoir and heat sink to cool the water.

  15. Cooled railplug

    DOEpatents

    Weldon, W.F.

    1996-05-07

    The railplug is a plasma ignitor capable of injecting a high energy plasma jet into a combustion chamber of an internal combustion engine or continuous combustion system. An improved railplug is provided which has dual coaxial chambers (either internal or external to the center electrode) that provide for forced convective cooling of the electrodes using the normal pressure changes occurring in an internal combustion engine. This convective cooling reduces the temperature of the hot spot associated with the plasma initiation point, particularly in coaxial railplug configurations, and extends the useful life of the railplug. The convective cooling technique may also be employed in a railplug having parallel dual rails using dual, coaxial chambers. 10 figs.

  16. Extracellular superoxide production associated with secondary root growth following desiccation of Pisum sativum seedlings.

    PubMed

    Roach, Thomas; Kranner, Ilse

    2011-10-15

    The seedling stage is arguably the most vulnerable phase in the plant life cycle, where the young establishing plant is extremely sensitive to environmental stresses such as drought. Here, the production of superoxide (O(2)(-)), a molecule involved in stress signaling, was measured in response to desiccation of Pisum sativum L. seedlings. Following desiccation that was sufficient to kill the radicle meristem, viability could be retained by seedlings that grew secondary roots. Upon rehydration, secondary roots formed in a region that had displayed intense extracellular O(2)(-)production on desiccation. Treating partially desiccated seedlings with hydrogen peroxide (H(2)O(2)) prevented viability loss. In summary, reactive oxygen species (ROS) appear to participate in the signaling required for secondary root formation following desiccation stress of P. sativum seedlings.

  17. Performance evaluation of two black nickel and two black chrome solar collectors

    NASA Technical Reports Server (NTRS)

    Losey, R.

    1977-01-01

    The test program was based on the evaluation of four unique solar collectors described below: (1) black nickel collector surface with a desiccant drying bed, (2) black nickel collector surface without a desiccant drying bed, (3) black chrome collector surface with a dessicant drying bed, and (4) black chrome collector surface without a desiccant drying bed. The test program included three distinct phases: Initial performance evaluation, natural environmental aging, and post-aging performance evaluation. Results of Phase III testing conclusively indicated a higher normalized efficiency for Black Chrome surfaces when compared to Black Nickel.

  18. Solar Central Receiver Hybrid Power Systems sodium-cooled receiver concept. Final report. Volume II, Book 1. Conceptual design, Sections 1 through 4

    SciTech Connect

    1980-01-01

    The overall, long-term objective of the Solar Central Receiver Hybrid Power System program is to identify, characterize, and ultimately demonstrate the viability and cost effectiveness of solar/fossil, steam Rankine cycle, hybrid power systems that: (1) consist of a combined solar central receiver energy source and a nonsolar energy source at a single, common site, (2) may operate in the base, intermediate, and peaking capacity modes, (3) produce the rated output independent of variations in solar insolation, (4) provide a significant savings (50% or more) in fuel consumption, and (5) produce power at the minimum possible cost in mills/kWh. It is essential that these hybrid concepts be technically feasible and economically competitive with other systems in the near to mid-term time period (1985-1990) on a commercial scale. The program objective for Phase I is to identify and conceptually characterize solar/fossil steam Rankine cycle, commercial-scale, power plant systems that are economically viable and technically feasible. This volume presents in detail the market analysis, parametric analysis, and the selection process for the preferred system. (WHK)

  19. Extended periods of hydration do not elicit dehardening to desiccation tolerance in regeneration trials of the moss Syntrichia caninervis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dehardening (deacclimation) to water stress is seldom studied in plants, and yet is an integral phase of desiccation tolerance. Most bryophytes are desiccation tolerant (DT), and yet even fully DT species lose a significant portion of their ability to withstand desiccation if dehardened. Shoots of t...

  20. Listeria monocytogenes ability to survive desiccation: Influence of serotype, origin, virulence, and genotype.

    PubMed

    Zoz, Fiona; Grandvalet, Cosette; Lang, Emilie; Iaconelli, Cyril; Gervais, Patrick; Firmesse, Olivier; Guyot, Stéphane; Beney, Laurent

    2017-02-21

    Listeria monocytogenes, a bacterium that is responsible for listeriosis, is a very diverse species. Desiccation resistance has been rarely studied in L. monocytogenes, although it is a stress that is largely encountered by this microorganism in food-processing environments and that could be managed to prevent its presence. The objective of this study was to evaluate the resistance of 30 L. monocytogenes strains to moderate desiccation (75% relative humidity) and evaluate the correlation of such resistance with the strains' virulence, serotype and genotype. The results showed a great heterogeneity of strains regarding their ability to survive (loss of cultivability between 0.4 and 2.0 log). Strains were classified into three groups according to desiccation resistance (sensitive, intermediate, or resistant), and the strain repartition was analyzed relative to serotype, virulence level and environmental origin of the strains. No correlation was found between isolate origin and desiccation resistance. All serotype 1/2b strains were classified into the group of resistant strains. Virulent and hypovirulent strains were distributed among the three groups of desiccation resistance. Finally, a genomic comparison was performed based on 31 genes that were previously identified as being involved in desiccation resistance. The presence of those genes was localized among the genomes of some strains and compared regarding strain-resistance levels. High nucleotide conservation was identified between resistant and desiccation-sensitive strains. In conclusion, the findings regarding the strains of serotype 1/2b indicate potential serotype-specific resistance to desiccation, and thus, to relative humidity fluctuations potentially encountered in food-related environments. The genomic comparison of 31 genes associated to desiccation tolerance did not reveal differences among four strains which have different level of resistance to desiccation.

  1. Rapid changes in desiccation resistance in Drosophila melanogaster are facilitated by changes in cuticular permeability.

    PubMed

    Bazinet, Aimee L; Marshall, Katie E; MacMillan, Heath A; Williams, Caroline M; Sinclair, Brent J

    2010-12-01

    Insects can improve their desiccation resistance by one or more of (1) increasing their water content; (2) decreasing water loss rate; or (3) increasing the amount of water able to be lost before death. Female Drosophila melanogaster have previously been reported to increase their resistance to desiccation after a desiccation pre-treatment and recovery, but the mechanism of this increased desiccation resistance has not been explored. We show that female, but not male adult D. melanogaster increased their resistance to desiccation after 1h of recovery from a 3 to 4.5h pre-treatment that depletes them of 10% of their water content. The pre-treatment did not result in an increase in water content after recovery, and there is a slight increase in water content at death in pre-treated females (but no change in males), suggesting that the amount of water loss tolerated is not improved. Metabolic rate, measured on individual flies with flow-through respirometry, did not change with pre-treatment. However, a desiccation pre-treatment did result in a reduction in water loss rate, and further investigation indicated that a change in cuticular water loss rate accounted for this decrease. Thus, the observed increase in desiccation resistance appears to be based on a change in cuticular permeability. However, physiological changes in response to the desiccation pre-treatment were similar in male and female, which therefore does not account for the difference in rapid desiccation hardening between the sexes. We speculate that sex differences in fuel use during desiccation may account for the discrepancy.

  2. Desiccation tolerance in Anopheles coluzzii: the effects of spiracle size and cuticular hydrocarbons

    PubMed Central

    Arcaz, Arthur C.; Huestis, Diana L.; Dao, Adama; Yaro, Alpha S.; Diallo, Moussa; Andersen, John; Blomquist, Gary J.; Lehmann, Tovi

    2016-01-01

    ABSTRACT The African malaria mosquitoes Anopheles gambiae and Anopheles coluzzii range over forests and arid areas, where they withstand dry spells and months-long dry seasons, suggesting variation in their desiccation tolerance. We subjected a laboratory colony (G3) and wild Sahelian mosquitoes during the rainy and dry seasons to desiccation assays. The thoracic spiracles and amount and composition of cuticular hydrocarbons (CHCs) of individual mosquitoes were measured to determine the effects of these traits on desiccation tolerance. The relative humidity of the assay, body water available, rate of water loss and water content at death accounted for 88% of the variation in desiccation tolerance. Spiracle size did not affect the rate of water loss or desiccation tolerance of the colony mosquitoes, as was the case for the total CHCs. However, six CHCs accounted for 71% of the variation in desiccation tolerance and three accounted for 72% of the variation in the rate of water loss. Wild A. coluzzii exhibited elevated desiccation tolerance during the dry season. During that time, relative thorax and spiracle sizes were smaller than during the rainy season. A smaller spiracle size appeared to increase A. coluzzii's desiccation tolerance, but was not statistically significant. Seasonal changes in CHC composition were detected in Sahelian A. coluzzii. Stepwise regression models suggested the effect of particular CHCs on desiccation tolerance. In conclusion, the combination of particular CHCs along with the total amount of CHCs is a primary mechanism conferring desiccation tolerance in A. coluzzii, while variation in spiracle size might be a secondary mechanism. PMID:27207644

  3. Cooling vest

    NASA Technical Reports Server (NTRS)

    Kosmo, J.; Kane, J.; Coverdale, J.

    1977-01-01

    Inexpensive vest of heat-sealable urethane material, when strapped to person's body, presents significant uncomplicated cooling system for environments where heavy accumulation of metabolic heat exists. Garment is applicable to occupations where physical exertion is required under heavy protective clothing.

  4. Preliminary design package for solar collector and solar pump

    NASA Technical Reports Server (NTRS)

    1978-01-01

    A solar-operated pump using an existing solar collector, for use on solar heating and cooling and hot water systems is described. Preliminary design criteria of the collector and solar-powered pump is given including: design drawings, verification plans, and hazard analysis.

  5. High-Performance Energy-Efficient Cool Metal Roof Assemblies Utilizing Building Integrated Renewable Solar Energy Technologies for New and Retrofit Building Construction

    DTIC Science & Technology

    2014-04-01

    Summary ........................................................................................................................ 1 1.0 INTRODUCTION ...Sustainment, Restoration, and Modernization FSEC Florida Solar Energy Center GFAFB Goodfellow Air Force Base HFT Heat Flux Transducer HVAC...discussed in more detail in Section 8 Implementation Issues. 7 1.0 INTRODUCTION A successful outcome of this project will lead to the

  6. Methods of beam cooling

    SciTech Connect

    Sessler, A.M.

    1996-02-01

    Diverse methods which are available for particle beam cooling are reviewed. They consist of some highly developed techniques such as radiation damping, electron cooling, stochastic cooling and the more recently developed, laser cooling. Methods which have been theoretically developed, but not yet achieved experimentally, are also reviewed. They consist of ionization cooling, laser cooling in three dimensions and stimulated radiation cooling.

  7. Development, testing, and certification of Calmac Mfg. Corp. solar collector and solar operated pump

    NASA Technical Reports Server (NTRS)

    Parker, J. C.

    1979-01-01

    Development of a rubber tube solar collector and solar operated pump for use with solar heating and cooling systems is discussed. The development hardware, problems encountered during fabrication and testing, and certification statements of performance are included.

  8. The desiccation tolerant secrets of Selaginella lepidophylla: what we have learned so far?

    PubMed

    Pampurova, Suzana; Van Dijck, Patrick

    2014-07-01

    Selaginella lepidophylla is a desiccation tolerant plant able to survive complete vegetative tissue dehydration and revive ('resurrect') in water conditions. Vegetative desiccation tolerance is an adaptive feature acquired by S. lepidophylla to withstand the long dry periods in its natural habitat, the Chihuahuan desert. Understanding the molecular basis of its drought stress tolerance may be of great benefit to help in developing novel strategies for improvement of drought stress tolerance in crops. Cell biological (e.g. gene discovery, comparative EST analysis, proteomics, metabolite profiling), ultrastructural and physiological studies have brought modest but already important insights in the desiccation tolerance mechanisms adapted by S. lepidophylla. Until recently, the desiccation tolerant mechanism of S. lepidophylla was related to its high trehalose levels. However, large-scale comparative metabolic analysis between S. lepidophylla and its desiccation susceptible relative Selaginella moellendorffii, unexpectedly revealed that S. moellendorffii contains higher trehalose levels than S. lepidophylla. Interestingly, polyols, such as sorbitol and xylitol are 100× more abundant in S. lepidophylla compared to S. moellendorffii. Whether this is linked to the higher stress tolerance remains to be established. Apart from these metabolites, we will also discuss the ultrastructural features that seem to play an important role in the desiccation tolerance of S. lepidophylla. Finally we discuss desiccation tolerance mechanism in other plant species.

  9. Relaxation nuclear magnetic resonance imaging (R-NMRI) of desiccation in M9787 silicone pads.

    SciTech Connect

    Alam, Todd M; Cherry, Brian Ray; Alam, Mary Kathleen

    2004-06-01

    The production and aging of silicone materials remains an important issue in the weapons stockpile due to their utilization in a wide variety of components and systems within the stockpile. Changes in the physical characteristics of silicone materials due to long term desiccation has been identified as one of the major aging effects observed in silicone pad components. Here we report relaxation nuclear magnetic resonance imaging (R-NMRI) spectroscopy characterization of the silica-filled and unfilled polydimethylsiloxane (PDMS) and polydiphenylsiloxane (PDPS) copolymer (M9787) silicone pads within desiccating environments. These studies were directed at providing additional details about the heterogeneity of the desiccation process. Uniform NMR spin-spin relaxation time (T2) images were observed across the pad thickness indicating that the drying process is approximately uniform, and that the desiccation of the M9787 silicone pad is not a H2O diffusion limited process. In a P2O5 desiccation environment, significant reduction of T2 was observed for the silica-filled and unfilled M9787 silicone pad for desiccation up to 225 days. A very small reduction in T2 was observed for the unfilled copolymer between 225 and 487 days. The increase in relative stiffness with desiccation was found to be higher for the unfilled copolymer. These R-NMRI results are correlated to local changes in the modulus of the material

  10. Aquatic insects dealing with dehydration: do desiccation resistance traits differ in species with contrasting habitat preferences?

    PubMed Central

    Velasco, Josefa; Millán, Andrés; Bilton, David T.; Arribas, Paula

    2016-01-01

    Background Desiccation resistance shapes the distribution of terrestrial insects at multiple spatial scales. However, responses to drying stress have been poorly studied in aquatic groups, despite their potential role in constraining their distribution and diversification, particularly in arid and semi-arid regions. Methods We examined desiccation resistance in adults of four congeneric water beetle species (Enochrus, family Hydrophilidae) with contrasting habitat specificity (lentic vs. lotic systems and different salinity optima from fresh- to hypersaline waters). We measured survival, recovery capacity and key traits related to desiccation resistance (fresh mass, % water content, % cuticle content and water loss rate) under controlled exposure to desiccation, and explored their variability within and between species. Results Meso- and hypersaline species were more resistant to desiccation than freshwater and hyposaline ones, showing significantly lower water loss rates and higher water content. No clear patterns in desiccation resistance traits were observed between lotic and lentic species. Intraspecifically, water loss rate was positively related to specimens’ initial % water content, but not to fresh mass or % cuticle content, suggesting that the dynamic mechanism controlling water loss is mainly regulated by the amount of body water available. Discussion Our results support previous hypotheses suggesting that the evolution of desiccation resistance is associated with the colonization of saline habitats by aquatic beetles. The interespecific patterns observed in Enochrus also suggest that freshwater species may be more vulnerable than saline ones to drought intensification expected under climate change in semi-arid regions such as the Mediterranean Basin. PMID:27635346

  11. Desiccation tolerance in resurrection plants: new insights from transcriptome, proteome and metabolome analysis.

    PubMed

    Dinakar, Challabathula; Bartels, Dorothea

    2013-01-01

    Most higher plants are unable to survive desiccation to an air-dried state. An exception is a small group of vascular angiosperm plants, termed resurrection plants. They have evolved unique mechanisms of desiccation tolerance and thus can tolerate severe water loss, and mostly adjust their water content with the relative humidity in the environment. Desiccation tolerance is a complex phenomenon and depends on the regulated expression of numerous genes during dehydration and subsequent rehydration. Most of the resurrection plants have a large genome and are difficult to transform which makes them unsuitable for genetic approaches. However, technical advances have made it possible to analyze changes in gene expression on a large-scale. These approaches together with comparative studies with non-desiccation tolerant plants provide novel insights into the molecular processes required for desiccation tolerance and will shed light on identification of orphan genes with unknown functions. Here, we review large-scale recent transcriptomic, proteomic, and metabolomic studies that have been performed in desiccation tolerant plants and discuss how these studies contribute to understanding the molecular basis of desiccation tolerance.

  12. Identification of proteins involved in desiccation tolerance in the red seaweed Pyropia orbicularis (Rhodophyta, Bangiales).

    PubMed

    López-Cristoffanini, Camilo; Zapata, Javier; Gaillard, Fanny; Potin, Philippe; Correa, Juan A; Contreras-Porcia, Loretto

    2015-12-01

    Extreme reduction in cellular water content leads to desiccation, which, if persistent, affects the physiology of organisms, mainly through oxidative stress. Some organisms are highly tolerant to desiccation, including resurrection plants and certain intertidal seaweeds. One such species is Pyropia orbicularis, a rhodophycean that colonizes upper intertidal zones along the Chilean coast. Despite long, daily periods of air exposure due to tides, this alga is highly tolerant to desiccation. The present study examined the proteome of P. orbicularis by 2DE and LC-MS/MS analyses to determine the proteins associated with desiccation tolerance (DT). The results showed that, under natural conditions, there were significant changes in the protein profile during low tide as compared to naturally hydrated plants at high tide. These changes were mainly in newly appeared proteins spots such as chaperones, monodehydroascorbate reductase, and manganese superoxide dismutase, among others. Previously undescribed proteins under desiccation conditions included phycobiliproteins, glyoxalase I, and phosphomannomutase. These changes evidenced that several physiological responses involved in DT are activated during low tide, including decreased photosynthetic activity, increased antioxidant capacity, and the preservation of cell physiology by regulating water content, cell wall structure, and cell volume. Similar responses have been observed in resurrection plants and bryophytes exposed to desiccation. Therefore, the coordinated activation of different desiccation tolerance pathways in P. orbicularis could explain the successful biological performance of this seaweed in the upper intertidal rocky zones.

  13. Method and apparatus for extracting water from air using a desiccant

    DOEpatents

    Spletzer, Barry L.; Callow, Diane Schafer

    2003-01-01

    The present invention provides a method and apparatus for extracting liquid water from moist air using minimal energy input. The method can be considered as four phases: (1) adsorbing water from air into a desiccant, (2) isolating the water-laden desiccant from the air source, (3) desorbing water as vapor from the desiccant into a chamber, and (4) isolating the desiccant from the chamber, and compressing the vapor in the chamber to form liquid condensate. The liquid condensate can be removed for use. Careful design of the dead volumes and pressure balances can minimize the energy required. The dried air can be exchanged for fresh moist air and the process repeated. An apparatus comprises a first chamber in fluid communication with a desiccant, and having ports to intake moist air and exhaust dried air. The apparatus also comprises a second chamber in fluid communication with the desiccant. The second chamber allows variable internal pressure, and has a port for removal of liquid condensate. Each chamber can be configured to be isolated or in communication with the desiccant. The first chamber can be configured to be isolated or in communication with a course of moist air. Various arrangements of valves, pistons, and chambers are described.

  14. Experimental and numerical investigation on the performance of an internally cooled dehumidifier

    NASA Astrophysics Data System (ADS)

    Turgut, Oguz Emrah; Çoban, Mustafa Turhan

    2016-12-01

    Liquid desiccant based dehumidifiers are important components of the air conditioning applications. Internally cooled dehumidifiers with liquid desiccants are deemed to be superior to the adiabatic types, thanks to the cooling medium which takes away the latent heat of vaporization occured when moist air contacts with liquid desiccant. However, its utilization in industrial applications is restricted due to the inherent corrosive characteristics of the liquid desiccants. In this study, an experimental chamber is built for epoxy coated plate fin type dehumidifier which is used in order to diminish the corrosive effect of the lithium chloride aqueous solution. Dehumidification effectiveness and moisture removal rate, two parameter indices, are adopted to measure the performance of the air conditioning system. The effect of inlet operating parameters on moisture removal rates is extensively analyzed. Two dimensional numerical model adapted from the conservation principles is utilized for obtainment of output parameters. Experimental results are compared with the numerical model and comparisons show that numerical outputs agrees with the experimental results. And also, dehumidification performance of lithium chloride and lithium bromide aqueous solutions are evaluated and compared against each other.

  15. Field Demonstration of Active Desiccant Modules Designed to Integrate with Standard Unitary Rooftop Package Equipment - Final Report: Phase 3

    SciTech Connect

    Fischer, J

    2004-03-15

    overall electrical energy consumption and a 12.5-kW reduction in peak demand. The cost of gas used for regeneration of the desiccant wheel over this period of time is estimated to be only $740, using a gas cost of $0.50 per therm--the summer rate in 2001. The estimated net savings is $5400 annually, resulting in a 1-2 year payback. It is likely that similar energy/cost savings were realized at the Callaway Gardens hotel. In this installation, however, a central plant supplied the chilled water serving fan coil units in the hotel wing retrofitted with the ADM, so it was not metered separately. Consequently, the owner could not provide actual energy consumption data specific to the facility. The energy and operating cost savings at both sites are directly attributable to higher cooling-season thermostat settings and decreased conventional system run times. These field installations were selected as an immediate and appropriate response to correct indoor humidity and fresh air ventilation problems being experienced by building occupants and owners, so no rigorous baseline-building vs. test-building energy use/operating cost savings results can be presented. The report presents several simulated comparisons between the ADM/roof HVAC approach and other equipment combinations, where both desiccant and conventional systems are modeled to provide comparable fresh air ventilation rates and indoor humidity levels. The results obtained from these simulations demonstrate convincingly the energy and operating cost savings obtainable with this hybrid desiccant/vapor-compression technology, verifying those actually seen at the pilot installations. The ADM approach is less expensive than conventional alternatives providing similar performance and indoor air quality and provides a very favorable payback (1 year or so) compared with oversized rooftop units that cannot be operated effectively with the necessary high outdoor air percentages.

  16. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

    ERIC Educational Resources Information Center

    Longe, Karen M.; McClelland, Michael J.

    Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

  17. Cool Sportswear

    NASA Technical Reports Server (NTRS)

    1982-01-01

    New athletic wear design based on the circulating liquid cooling system used in the astronaut's space suits, allows athletes to perform more strenuous activity without becoming overheated. Techni-Clothes gear incorporates packets containing a heat-absorbing gel that slips into an insulated pocket of the athletic garment and is positioned near parts of the body where heat transfer is most efficient. A gel packet is good for about one hour. Easily replaced from a supply of spares in an insulated container worn on the belt. The products, targeted primarily for runners and joggers and any other athlete whose performance may be affected by hot weather, include cooling headbands, wrist bands and running shorts with gel-pack pockets.

  18. Generational Differences in Response to Desiccation Stress in the Desert Moss Tortula inermis

    PubMed Central

    Stark, Lloyd R.; Oliver, Melvin J.; Mishler, Brent D.; McLetchie, D. Nicholas

    2007-01-01

    Background and Aims Active growth in post-embryonic sporophytes of desert mosses is restricted to the cooler, wetter months. However, most desert mosses have perennial gametophytes. It is hypothesized that these life history patterns are due, in part, to a reduced desiccation tolerance for sporophytes relative to gametophytes. Methods Gametophytes with attached post-embryonic sporophytes of Tortula inermis (early seta elongation phenophase) were exposed to two levels of desiccation stress, one rapid-dry cycle and two rapid-dry cycles, then moistened and allowed to recover, resume development, and/or regenerate for 35 d in a growth chamber. Key Results Gametophytes tolerated the desiccation treatments well, with 93 % survival through regenerated shoot buds and/or protonemata. At the high stress treatment, a significantly higher frequency of burned leaves and browned shoots occurred. Sporophytes were far more sensitive to desiccation stress, with only 23 % surviving after the low desiccation stress treatment, and 3 % surviving after the high desiccation stress treatment. While the timing of protonemal production and sporophytic phenophases was relatively unaffected by desiccation stress, shoots exposed to one rapid-dry cycle produced shoots more rapidly than shoots exposed to two rapid-dry cycles. Conclusions It is concluded that sporophytes of Tortula inermis are more sensitive to rapid drying than are maternal gametophytes, and that sporophyte abortion in response to desiccation results from either reduced desiccation tolerance of sporophytes relative to gametophytes, or from a termination of the sporophyte on the part of the gametophyte in response to stress. PMID:17098752

  19. Changes in some thylakoid membrane proteins and pigments upon desiccation of the resurrection plant Haberlea rhodopensis.

    PubMed

    Georgieva, Katya; Röding, Anja; Büchel, Claudia

    2009-09-15

    The changes in some proteins involved in the light reactions of photosynthesis of the resurrection plant Haberlea rhodopensis were examined in connection with desiccation. Fully hydrated (control) and completely desiccated plants (relative water content (RWC) 6.5%) were used for thylakoid preparations. The chlorophyll (Chl) a to Chl b ratios of thylakoids isolated from control and desiccated leaves were very similar, which was also confirmed by measuring their absorption spectra. HPLC analysis revealed that beta-carotene content was only slightly enhanced in desiccated leaves compared with the control, but the zeaxanthin level was strongly increased. Desiccation of H. rhodopensis to an air-dried state at very low light irradiance led to a little decrease in the level of D1, D2, PsbS and PsaA/B proteins in thylakoids, but a relative increase in LHC polypeptides. To further elucidate whether the composition of the protein complexes of the thylakoid membranes had changed, we performed a separation of solubilized thylakoids on sucrose density gradients. In contrast to spinach, Haberlea thylakoids appeared to be much more resistant to the same solubilization procedure, i.e. complexes were not separated completely and complexes of higher density were found. However, the fractions analyzed provided clear evidence for a move of part of the antenna complexes from PSII to PSI when plants became desiccated. This move was also confirmed by low temperature emission spectra of thylakoids. Overall, the photosynthetic proteins remained comparatively stable in dried Haberlea leaves when plants were desiccated under conditions similar to their natural habitat. Low light during desiccation was enough to induce a rise in the xanthophyll zeaxanthin and beta-carotene. Together with the extensive leaf shrinkage and some leaf folding, increased zeaxanthin content and the observed shift in antenna proteins from PSII to PSI during desiccation of Haberlea contributed to the integrity of the

  20. Water Content, Raffinose, and Dehydrins in the Induction of Desiccation Tolerance in Immature Wheat Embryos

    PubMed Central

    Black, Michael; Corbineau, Françoise; Gee, Harry; Côme, Daniel

    1999-01-01

    Desiccation tolerance is initiated in wheat (Triticum aestivum L.) embryos in planta at 22 to 24 d after anthesis, at the time that the embryo water content has decreased from about 73% fresh weight (2.7 g water/g dry weight) to about 65% fresh weight (1.8 g water/g dry weight). To determine if desiccation tolerance is fully induced by the loss of a relatively small amount of water, detached wheat grains were treated to reduce the embryo water content by just a small amount to approximately 69% (2.2 g water/g dry weight). After 24 h of such incipient water loss, subsequently excised embryos were able to withstand severe desiccation, whereas those embryos that had not previously lost water could not. Therefore, a relatively small decrease in water content for only 24 h acts as the signal for the development of desiccation tolerance. Embryos that were induced into tolerance by a 24-h water loss had no detectable raffinose. The oligosaccharide accumulated at later times even in embryos of detached grains that had not become desiccation tolerant, although tolerant embryos (i.e. those that previously had lost some water) contained larger amounts of the carbohydrate. It is concluded that desiccation tolerance and the occurrence of raffinose are not correlated. Immunodetected dehydrins accumulated in embryos in planta as desiccation tolerance developed. Detachment of grains induced the appearance of dehydrins at an earlier age, even in embryos that had not been made desiccation tolerant by incipient drying. It is concluded that a small reduction in water content induces desiccation tolerance by initiating changes in which dehydrins might participate but not by their interaction with raffinose. PMID:10364397

  1. The precipitation response to the desiccation of Lake Chad

    SciTech Connect

    Lauwaet D.; VanWeverberg K.; vanLipzig, N. P. M., Weverberg, K. V., Ridderb, K. D., and Goyens, C.

    2012-04-01

    Located in the semi-arid African Sahel, Lake Chad has shrunk from a surface area of 25000 km2 in 1960 to about 1350 km2 due to a series of droughts and anthropogenic influences. The disappearance of such a large open-water body can be expected to have a noticeable effect on the meteorology in the surroundings of the lake. The impact could extend even further to the west as westward propagating convective systems pass Lake Chad in the rainfall season. This study examines the sensitivity of the regional hydrology and convective processes to the desiccation of the lake using a regional atmospheric model. Three Lake Chad scenarios are applied reflecting the situation in 1960, the current situation and a potential future scenario in which the lake and the surrounding wetlands have disappeared. The model simulations span the months July-September in 2006, which includes the rainfall season in the Lake Chad area. Total precipitation amounts and the components of the hydrological cycle are found to be hardly affected by the existence of the lake. A filled Lake Chad does, however, increase the precipitation at the east side of the lake. The model results indicate that the boundary layer moisture and temperature are significantly altered downwind of the lake. By investigating a mesoscale convective system (MCS) case, this is found to affect the development and progress of the system. At first, the MCS is intensified by the more unstable boundary layer air but the persistence of the system is altered as the cold pool propagation becomes less effective. The proposed mechanism is able to explain the differences in the rainfall patterns nearby Lake Chad between the scenarios. This highlights the local sensitivity to the desiccation of Lake Chad whereas the large-scale atmospheric processes are not affected.

  2. Cooling technique

    DOEpatents

    Salamon, Todd R; Vyas, Brijesh; Kota, Krishna; Simon, Elina

    2017-01-31

    An apparatus and a method are provided. Use is made of a wick structure configured to receive a liquid and generate vapor in when such wick structure is heated by heat transferred from heat sources to be cooled off. A vapor channel is provided configured to receive the vapor generated and direct said vapor away from the wick structure. In some embodiments, heat conductors are used to transfer the heat from the heat sources to the liquid in the wick structure.

  3. Solar radiative forcing at selected locations and evidence for global lower tropospheric cooling following the eruptions of El Chichon and Pinatubo

    SciTech Connect

    Dutton, E.G. ); Christy, J.R. )

    1992-12-02

    As a result of the eruption of Mt. Pinatubo (June 1991), direct solar radiation was observed to decrease by as much as 25-30% at four remote locations widely distributed in latitude. The average total aerosol optical depth for the first 10 months after the Pinatubo eruption at those sites is 1.7 times greater than that observed following the 1982 eruption of El Chichon. Monthly-mean clear-sky total solar irradiance at Mauna Loa, Hawaii, decreased by as much as 5% and averaged 2.4% and 2.7% in the first 10 months after the El Chichon and Pinatubo eruptions, respectively. By September 1992 the global and northern hemispheric lower tropospheric temperatures had decreased 0.5[degrees]C and 0.7[degrees]C, respectively compared to pre-Pinatubo levels. The temperature record examined consists of globally uniform observations from satellite microwave sounding units.

  4. Laboratory and Modeling Evaluations in Support of Field Testing for Desiccation at the Hanford Site

    SciTech Connect

    Truex, Michael J.; Oostrom, Martinus; Freedman, Vicky L.; Strickland, Christopher E.; Wietsma, Thomas W.; Tartakovsky, Guzel D.; Ward, Anderson L.

    2011-02-23

    The Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau includes testing of the desiccation technology as a potential technology to be used in conjunction with surface infiltration control to limit the flux of technetium and other contaminants in the vadose zone to the groundwater. Laboratory and modeling efforts were conducted to investigate technical uncertainties related to the desiccation process and its impact on contaminant transport. This information is intended to support planning, operation, and interpretation of a field test for desiccation in the Hanford Central Plateau.

  5. Tolerance to oxidative stress induced by desiccation in Porphyra columbina (Bangiales, Rhodophyta)

    PubMed Central

    Contreras-Porcia, Loretto; Thomas, Daniela; Flores, Verónica; Correa, Juan A.

    2011-01-01

    Unravelling the mechanisms underlying desiccation tolerance is crucial in order to understand the position of algal species in the intertidal zone. The alga Porphyra columbina lives in the uppermost part of the rocky intertidal zones around the world and was selected as a model for this study. Naturally desiccated plants were collected during low tide and studied for morphological changes, oxidative burst induction, biomolecule oxidation, antioxidant responses, and photosynthetic status. Naturally hydrated plants collected during high tides were used for comparative purposes. In addition, changes induced by desiccation were assessed in vitro and the capacity to recover from desiccation was determined by rehydrating the fronds in seawater. The global results show that desiccation induces morphological and cellular alterations accompanied by a loss of ∼96% of the water content. Overproduction of reactive oxygen species (ROS) was induced by desiccation and two peaks of H2O2 were detected at 1 and 3 h of desiccation. However, during in vitro rehydration post-desiccation, the ROS quickly returned to the basal levels. At the biomolecular level, only a low production of oxidized proteins was recorded during desiccation, whereas the activity of diverse antioxidant enzymes increased. However, this activity diminished to near basal levels during rehydration. The photosynthetic efficiency (Fv/Fm) during desiccation declined by 94–96% of the values recorded in hydrated plants. This reduction was generated by the low levels of trapped energy flux per cross-section (TRo/CS), electron transport flux per CS (ETo/CS), and density of reaction centres (RC/SCo) as well as the chlorophyll content. The inverse pattern was observed for the levels of phycocyanin and phycoerythrin content. Fv/Fm and the photosynthetic indicators were restored to normal levels after only 5 min of rehydration. The results indicate that desiccation in P. columbina causes overproduction of ROS that is

  6. Tolerance to oxidative stress induced by desiccation in Porphyra columbina (Bangiales, Rhodophyta).

    PubMed

    Contreras-Porcia, Loretto; Thomas, Daniela; Flores, Verónica; Correa, Juan A

    2011-03-01

    Unravelling the mechanisms underlying desiccation tolerance is crucial in order to understand the position of algal species in the intertidal zone. The alga Porphyra columbina lives in the uppermost part of the rocky intertidal zones around the world and was selected as a model for this study. Naturally desiccated plants were collected during low tide and studied for morphological changes, oxidative burst induction, biomolecule oxidation, antioxidant responses, and photosynthetic status. Naturally hydrated plants collected during high tides were used for comparative purposes. In addition, changes induced by desiccation were assessed in vitro and the capacity to recover from desiccation was determined by rehydrating the fronds in seawater. The global results show that desiccation induces morphological and cellular alterations accompanied by a loss of ∼96% of the water content. Overproduction of reactive oxygen species (ROS) was induced by desiccation and two peaks of H(2)O(2) were detected at 1 and 3 h of desiccation. However, during in vitro rehydration post-desiccation, the ROS quickly returned to the basal levels. At the biomolecular level, only a low production of oxidized proteins was recorded during desiccation, whereas the activity of diverse antioxidant enzymes increased. However, this activity diminished to near basal levels during rehydration. The photosynthetic efficiency (F(v)/F(m)) during desiccation declined by 94-96% of the values recorded in hydrated plants. This reduction was generated by the low levels of trapped energy flux per cross-section (TRo/CS), electron transport flux per CS (ETo/CS), and density of reaction centres (RC/SCo) as well as the chlorophyll content. The inverse pattern was observed for the levels of phycocyanin and phycoerythrin content. F(v)/F(m) and the photosynthetic indicators were restored to normal levels after only 5 min of rehydration. The results indicate that desiccation in P. columbina causes overproduction of ROS

  7. The signature of seeds in resurrection plants: a molecular and physiological comparison of desiccation tolerance in seeds and vegetative tissues.

    PubMed

    Illing, Nicola; Denby, Katherine J; Collett, Helen; Shen, Arthur; Farrant, Jill M

    2005-11-01

    Desiccation-tolerance in vegetative tissues of angiosperms has a polyphyletic origin and could be due to 1) appropriation of the seed-specific program of gene expression that protects orthodox seeds against desiccation, and/or 2) a sustainable version of the abiotic stress response. We tested these hypotheses by comparing molecular and physiological data from the development of orthodox seeds, the response of desiccation-sensitive plants to abiotic stress, and the response of desiccation-tolerant plants to extreme water loss. Analysis of publicly-available gene expression data of 35 LEA proteins and 68 anti-oxidant enzymes in the desiccation-sensitive Arabidopsis thaliana identified 13 LEAs and 4 anti-oxidants exclusively expressed in seeds. Two (a LEA6 and 1-cys-peroxiredoxin) are not expressed in vegetative tissues in A. thaliana, but have orthologues that are specifically activated in desiccating leaves of Xerophyta humilis. A comparison of antioxidant enzyme activity in two desiccation-sensitive species of Eragrostis with the desiccation-tolerant E. nindensis showed equivalent responses upon initial dehydration, but activity was retained at low water content in E. nindensis only. We propose that these antioxidants are housekeeping enzymes and that they are protected from damage in the desiccation-tolerant species. Sucrose is considered an important protectant against desiccation in orthodox seeds, and we show that sucrose accumulates in drying leaves of E. nindensis, but not in the desiccation-sensitive Eragrostis species. The activation of "seed-specific" desiccation protection mechanisms (sucrose accumulation and expression of LEA6 and 1-cys-peroxiredoxin genes) in the vegetative tissues of desiccation-tolerant plants points towards acquisition of desiccation tolerance from seeds.

  8. Solar economy and technology update

    SciTech Connect

    Brotherton, T.K.

    1983-06-01

    The industry, national, and consumer perspectives on solar power are reviewed. With a 30% increase in dealer/installers, and a 30% attrition rate, about 60% of the participants in the market are ''new kids on the block.'' The installed value of the market was $750 million in 1981. There was a 30% decline in volumes, due to the recession, in 1982. As for the national perspective, solar is labor intensive, and generated a billion dollars worth of jobs. As the DOE has abandoned all but high risk ''core technology'' RandD has faltered some. But desiccant heat pumps, polymer collectors, and parabolic collectors are discussed.

  9. Cooling device

    SciTech Connect

    Teske, L.

    1984-02-21

    A cooling device is claimed for coal dust comprising a housing, a motor-driven conveyor system therein to transport the coal dust over coolable trays in the housing and conveyor-wheel arms of spiral curvature for moving the coal dust from one or more inlets to one or more outlets via a series of communicating passages in the trays over which the conveyor-wheel arms pass under actuation of a hydraulic motor mounted above the housing and driving a vertical shaft, to which the conveyor-wheel arms are attached, extending centrally downwardly through the housing.

  10. REACTOR COOLING

    DOEpatents

    Quackenbush, C.F.

    1959-09-29

    A nuclear reactor with provisions for selectively cooling the fuel elements is described. The reactor has a plurality of tubes extending throughout. Cylindrical fuel elements are disposed within the tubes and the coolant flows through the tubes and around the fuel elements. The fuel elements within the central portion of the reactor are provided with roughened surfaces of material. The fuel elements in the end portions of the tubes within the reactor are provlded with low conduction jackets and the fuel elements in the region between the central portion and the end portions are provided with smooth surfaces of high heat conduction material.

  11. Electron impact cross-sections and cooling rates for methane. [in thermal balance of electrons in atmospheres and ionospheres of planets and satellites in outer solar system

    NASA Technical Reports Server (NTRS)

    Gan, L.; Cravens, T. E.

    1992-01-01

    Energy transfer between electrons and methane gas by collisional processes plays an important role in the thermal balance of electrons in the atmospheres and ionospheres of planets and satellites in the outer solar system. The literature is reviewed for electron impact cross-sections for methane in this paper. Energy transfer rates are calculated for elastic and inelastic processes using a Maxwellian electron distribution. Vibrational, rotational, and electronic excitation and ionization are included. Results are presented for a wide range of electron temperatures and neutral temperatures.

  12. Experimental and Numerical Investigations of Soil Desiccation for Vadose Zone Remediation: Report for Fiscal Year 2007

    SciTech Connect

    Ward, Andy L.; Oostrom, Mart; Bacon, Diana H.

    2008-02-04

    Apart from source excavation, the options available for the remediation of vadose zone metal and radionuclide contaminants beyond the practical excavation depth (0 to 15 m) are quite limited. Of the available technologies, very few are applicable to the deep vadose zone with the top-ranked candidate being soil desiccation. An expert panel review of the work on infiltration control and supplemental technologies identified a number of knowledge gaps that would need to be overcome before soil desiccation could be deployed. The report documents some of the research conducted in the last year to fill these knowledge gaps. This work included 1) performing intermediate-scale laboratory flow cell experiments to demonstrate the desiccation process, 2) implementing a scalable version of Subsurface Transport Over Multiple Phases–Water-Air-Energy (STOMP-WAE), and 3) performing numerical experiments to identify the factors controlling the performance of a desiccation system.

  13. Responses of the Lichen Photobiont Trebouxia erici to Desiccation and Rehydration (II) Proteomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lichen desiccation tolerance is associated with cellular protection mechanisms directed against the oxidative stress produced during dehydration and/or rehydration, however, these mechanisms are not well understood. In other poikilohydric organisms, changes in the synthesis of proteins have bee...

  14. The glyoxylate shunt is essential for desiccation tolerance in C. elegans and budding yeast

    PubMed Central

    Erkut, Cihan; Gade, Vamshidhar R; Laxman, Sunil; Kurzchalia, Teymuras V

    2016-01-01

    Many organisms, including species from all kingdoms of life, can survive desiccation by entering a state with no detectable metabolism. To survive, C. elegans dauer larvae and stationary phase S. cerevisiae require elevated amounts of the disaccharide trehalose. We found that dauer larvae and stationary phase yeast switched into a gluconeogenic mode in which metabolism was reoriented toward production of sugars from non-carbohydrate sources. This mode depended on full activity of the glyoxylate shunt (GS), which enables synthesis of trehalose from acetate. The GS was especially critical during preparation of worms for harsh desiccation (preconditioning) and during the entry of yeast into stationary phase. Loss of the GS dramatically decreased desiccation tolerance in both organisms. Our results reveal a novel physiological role for the GS and elucidate a conserved metabolic rewiring that confers desiccation tolerance on organisms as diverse as worm and yeast. DOI: http://dx.doi.org/10.7554/eLife.13614.001 PMID:27090086

  15. cis-3-Chloroacrylic Acid: A New Cotton Defoliant and Crop Desiccant.

    PubMed

    Herrett, R A; Kurtz, A N

    1963-09-20

    cis-3-Chloroacrylic acid is a potent cotton defoliant and a crop desiccant. Relationships between structure and activity indicate a relatively high degree of specificity, since minor modifications in structure result in loss of activity.

  16. Development of desiccant based air conditioning for hotels and motels. Final report, phase 1

    SciTech Connect

    Banks, N.J.

    1994-10-01

    This report contains final reports from two phases of field tests: Phase I at the Marriott Courtyard in West Palm Beach, completed in October 1991, and Phase II at the Walt Disney World Swan Hotel in Orlando, completed in August 1993. The goal was to measure the performance and reliability of the desiccant units. The successfull program proved the value of the gas-fired desiccant technology to the hospitality industry. The desiccant units reduced moisture by 15 to 20% relative humidity. Measurements of temperature, humidity, and wallboard moisture content showed a dramatic reduction in the humidity levels experienced prior to installation of the units and in the control areas without desiccants. Moisture damage was kept in check and remodelling due to it was eliminated.

  17. High-frequency zone of river desiccation disasters in China and influencing factors.

    PubMed

    Jiongxin, X

    2001-07-01

    In recent years, the desiccation of the lower Yellow River has raised concerns in the government, public, and scientific community in China. Long-term and widespread desiccation of rivers is a disaster with many adverse environmental implications. It has been found in this study that there exists a high-frequency zone of river desiccation disasters at 34 degrees -42 degrees N in the North China Plain. The hazardous environment is characterized by semiarid climate, widely distributed thick loess in the basin and a "hanging river bed" in the plain as well as unfavorable man-water-land coupling relationships. In this setting, the sharply increased water diversion by man since the late 1950s led to the occurrence of river desiccation disasters in the lower reaches of the river in this area.

  18. Sugar sweet springtails: on the transcriptional response of Folsomia candida (Collembola) to desiccation stress.

    PubMed

    Timmermans, M J T N; Roelofs, D; Nota, B; Ylstra, B; Holmstrup, M

    2009-11-01

    Several species of Collembola survive stressful desiccating conditions by absorbing water vapour from the environment. To obtain insight into the transcriptomic responses underlying this 'water vapour absorption' mechanism we subjected Folsomia candida (Collembola) to transcriptome profiling. We show that ecologically relevant desiccation stress leads to strong time-dependent transcriptomic changes. Exposure of F. candida to 98.2% relative humidity over an interval of 174 h resulted in a high number of gene transcripts being differentially expressed (up to 41%; P-value < 0.05). Additional Gene Ontology analyses suggest that carbohydrate transport, sugar catabolism and cuticle maintenance are biological processes involved in combating desiccation. However, many additional pathways seem to be affected; additional experiments are needed to elucidate which responses are primarily linked to desiccation resistance.

  19. Fundamentals of Solar Heating. Correspondence Course.

    ERIC Educational Resources Information Center

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

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

  20. Thermal Inactivation of Desiccation-Adapted Salmonella spp. in Aged Chicken Litter

    PubMed Central

    Chen, Zhao; Diao, Junshu; Dharmasena, Muthu; Ionita, Claudia; Rieck, James

    2013-01-01

    Thermal inactivation of desiccation-adapted Salmonella spp. in aged chicken litter was investigated in comparison with that in a nonadapted control to examine potential cross-tolerance of desiccation-adapted cells to heat treatment. A mixture of four Salmonella serovars was inoculated into the finished compost with 20, 30, 40, and 50% moisture contents for a 24-h desiccation adaptation. Afterwards, the compost with desiccation-adapted cells was inoculated into the aged chicken litter with the same moisture content for heat treatments at 70, 75, 80, 85, and 150°C. Recovery media were used to allow heat-injured cells to resuscitate. A 5-log reduction in the number of the desiccation-adapted cells in aged chicken litter with a 20% moisture content required >6, >6, ∼4 to 5, and ∼3 to 4 h of exposure at 70, 75, 80, and 85°C, respectively. As a comparison, a 5-log reduction in the number of nonadapted control cells in the same chicken litter was achieved within ∼1.5 to 2, ∼1 to 1.5, ∼0.5 to 1, and <0.5 h at 70, 75, 80, and 85°C, respectively. The exposure time required to obtain a 5-log reduction in the number of desiccation-adapted cells gradually became shorter as temperature and moisture content were increased. At 150°C, desiccation-adapted Salmonella cells survived for 50 min in chicken litter with a 20% moisture content, whereas control cells were detectable by enrichment for only 10 min. Our results demonstrated that the thermal resistance of Salmonella in aged chicken litter was increased significantly when the cells were adapted to desiccation. This study also validated the effectiveness of thermal processing being used for producing chicken litter free of Salmonella contamination. PMID:24014540

  1. Global changes in DNA methylation in seeds and seedlings of Pyrus communis after seed desiccation and storage.

    PubMed

    Michalak, Marcin; Barciszewska, Mirosława Z; Barciszewski, Jan; Plitta, Beata P; Chmielarz, Paweł

    2013-01-01

    The effects of storage and deep desiccation on structural changes of DNA in orthodox seeds are poorly characterized. In this study we analyzed the 5-methylcytosine (m(5)C) global content of DNA isolated from seeds of common pear (Pyrus communis L.) that had been subjected to extreme desiccation, and the seedlings derived from these seeds. Germination and seedling emergence tests were applied to determine seed viability after their desiccation. In parallel, analysis of the global content of m(5)C in dried seeds and DNA of seedlings obtained from such seeds was performed with a 2D TLC method. Desiccation of fresh seeds to 5.3% moisture content (mc) resulted in a slight reduction of DNA methylation, whereas severe desiccation down to 2-3% mc increased DNA methylation. Strong desiccation of seeds resulted in the subsequent generation of seedlings of shorter height. A 1-year period of seed storage induced a significant increase in the level of DNA methylation in seeds. It is possible that alterations in the m(5)C content of DNA in strongly desiccated pear seeds reflect a reaction of desiccation-tolerant (orthodox) seeds to severe desiccation. Epigenetic changes were observed not only in severely desiccated seeds but also in 3-month old seedlings obtained from these seeds. With regard to seed storage practices, epigenetic assessment could be used by gene banks for early detection of structural changes in the DNA of stored seeds.

  2. Shoot desiccation and hydraulic failure in temperate woody angiosperms during an extreme summer drought.

    PubMed

    Nardini, Andrea; Battistuzzo, Marta; Savi, Tadeja

    2013-10-01

    Plant water status and hydraulics were measured in six woody angiosperms growing in a karstic woodland, during an extreme summer drought. Our aim was to take advantage of an unusual climatic event to identify key traits related to species-specific drought damage. The damage suffered by different species was assessed in terms of percentage of individuals showing extensive crown desiccation. Stem water potential (Ψstem ) and percent loss of hydraulic conductivity (PLC) were measured in healthy and desiccated individuals. Vulnerability to cavitation was assessed in terms of stem water potential inducing 50% PLC (Ψ50 ). Stem density (ρstem ) was also measured. Species-specific percentage of desiccated individuals was correlated to Ψ50 and ρstem . Crown desiccation was more widespread in species with less negative Ψ50 and lower ρstem . Desiccated individuals had lower Ψstem and higher PLC than healthy ones, suggesting that hydraulic failure was an important mechanism driving shoot dieback. Drought-vulnerable species showed lower safety margins (Ψstem  - Ψ50 ) than resistant ones. The Ψ50 , safety margins and ρstem values emerge as convenient traits to be used for tentative predictions of differential species-specific impact of extreme drought events on a local scale. The possibility that carbohydrate depletion was also involved in induction of desiccation symptoms is discussed.

  3. Distinct contractile and cytoskeletal protein patterns in the Antarctic midge are elicited by desiccation and rehydration.

    PubMed

    Li, Aiqing; Benoit, Joshua B; Lopez-Martinez, Giancarlo; Elnitsky, Michael A; Lee, Richard E; Denlinger, David L

    2009-05-01

    Desiccation presents a major challenge for the Antarctic midge, Belgica antarctica. In this study, we use proteomic profiling to evaluate protein changes in the larvae elicited by dehydration and rehydration. Larvae were desiccated at 75% relative humidity (RH) for 12 h to achieve a body water loss of 35%, approximately half of the water that can be lost before the larvae succumb to dehydration. To evaluate the rehydration response, larvae were first desiccated, then rehydrated for 6 h at 100% RH and then in water for 6 h. Controls were held continuously at 100% RH. Protein analysis was performed using 2-DE and nanoscale capillary LC/MS/MS. Twenty-four identified proteins changed in abundance in response to desiccation: 16 were more abundant and 8 were less abundant; 84% of these proteins were contractile or cytoskeletal proteins. Thirteen rehydration-regulated proteins were identified: 8 were more abundant and 5 were less abundant, and 69% of these proteins were also contractile or cytoskeletal proteins. Additional proteins responsive to desiccation and rehydration were involved in functions including stress responses, energy metabolism, protein synthesis, glucogenesis and membrane transport. We conclude that the major protein responses elicited by both desiccation and rehydration are linked to body contraction and cytoskeleton rearrangements.

  4. Radical formation and accumulation in vivo, in desiccation tolerant and intolerant mosses.

    PubMed

    Seel, W; Hendry, G; Atherton, N; Lee, J

    1991-01-01

    Water loss in a desiccation-sensitive moss resulted in destruction of chlorophyll, loss of carotenoids and increased lipid peroxidation, indicating the presence of damaging forms of activated oxygen. These effects were exaggerated when the plants were desiccated at high light intensities. During water-deprivation there was a build up of a free radical, detected in vivo, with a close correlation between molecular damage and radical accumulation. In contrast, in a desiccation-tolerant moss there was almost no indication of molecular (oxidative) damage. However a stable radical similar in type and concentration to that found in the desiccation-sensitive species accumulated, particularly under high irradiances. The stable radical appears to be one of the end-products of a process initiated by environmental stress, desiccation and high irradiance: its association with molecular damage depending on the degree to which the species is tolerant of desiccation. Identification of the radical in intact tissue from EPR and ENDOR studies, suggests that this is not a short-lived peroxy-radical but instead is relatively stable and carbon-centred.

  5. Method and composition for molding low-density desiccant syntactic-foam articles

    DOEpatents

    Not Available

    1981-12-07

    These and other objects of the invention are achieved by a process for molding to size a desiccant syntactic foam article having a density of 0.2 to 0.9 g/cc and a moisture capacity of 1 to 12% by weight, comprising the steps of: charging a mold with a powdery mixture of an activated desiccant, microspheres and a thermosetting resin, the amount of the desiccant being sufficient to provide the required moisture capacity, and the amounts of the microspheres and resin being such that the microspheres/desiccant volume fraction exceeds the packing factor by an amount sufficient to substantially avoid shrinkage without causing excessively high molding pressures; covering the mold and heating the covered mold to a temperature and for an amount of time sufficient to melt the resin; and tightly closing the mold and heating the closed mold to a temperature and for an amount of time sufficient to cure the resin, and removing the resultant desiccant syntactic foam article from the mold. In a composition of matter aspect, the present invention provides desiccant syntactic foam articles, and a composition of matter for use in molding the same.

  6. Campomanesia adamantium (Cambess.) O. Berg seed desiccation: influence on vigor and nucleic acids.

    PubMed

    Dresch, Daiane M; Masetto, Tathiana E; Scalon, Silvana P Q

    2015-01-01

    The aim of this study was to evaluate the sensitivity of Campomanesia adamantium seeds to desiccation by drying in activated silica gel (fast) and under laboratory conditions (slow). To assess the sensitivity of the seeds to desiccation, we used drying with silica gel and drying under laboratory conditions (25 °C), in order to obtain seeds with moisture content of 45, 35, 30, 25, 20, 15, 10 and 5%. The physiological potential of the seeds after desiccation was evaluated by measuring primary root protrusion, percentage of normal seedlings, germination seed index, seedling length, total seedling dry mass, electrical conductivity and DNA and RNA integrities. The C. adamantium seeds were sensitive to desiccation and to a reduction in moisture content to 21.1% or less by desiccation using silica gel, and to 17.2% or less by desiccation under laboratory conditions; impairment of the physiological potential of the seeds was observed at these low moisture content levels. The integrity of the seed genomic DNA was not affected after drying seeds in the two methods. However, drying in silica gel to 4.5% moisture content and drying under laboratory conditions to 5.4% moisture content resulted in the loss of seed RNA integrity.

  7. What distinguishes cyanobacteria able to revive after desiccation from those that cannot: the genome aspect.

    PubMed

    Murik, Omer; Oren, Nadav; Shotland, Yoram; Raanan, Hagai; Treves, Haim; Kedem, Isaac; Keren, Nir; Hagemann, Martin; Pade, Nadin; Kaplan, Aaron

    2017-02-01

    Filamentous cyanobacteria are the main founders and primary producers in biological desert soil crusts (BSCs) and are likely equipped to cope with one of the harshest environmental conditions on earth including daily hydration/dehydration cycles, high irradiance and extreme temperatures. Here, we resolved and report on the genome sequence of Leptolyngbya ohadii, an important constituent of the BSC. Comparative genomics identified a set of genes present in desiccation-tolerant but not in dehydration-sensitive cyanobacteria. RT qPCR analyses showed that the transcript abundance of many of them is upregulated during desiccation in L. ohadii. In addition, we identified genes where the orthologs detected in desiccation-tolerant cyanobacteria differs substantially from that found in desiccation-sensitive cells. We present two examples, treS and fbpA (encoding trehalose synthase and fructose 1,6-bisphosphate aldolase respectively) where, in addition to the orthologs present in the desiccation-sensitive strains, the resistant cyanobacteria also possess genes with different predicted structures. We show that in both cases the two orthologs are transcribed during controlled dehydration of L. ohadii and discuss the genetic basis for the acclimation of cyanobacteria to the desiccation conditions in desert BSC.

  8. Calorimetric Properties of Dehydrating Pollen (Analysis of a Desiccation-Tolerant and an Intolerant Species).

    PubMed Central

    Buitink, J.; Walters-Vertucci, C.; Hoekstra, F. A.; Leprince, O.

    1996-01-01

    The physical state of water in the desiccation-tolerant pollen of Typha latifolia L. and the desiccation-sensitive pollen of Zea mays L. was studied using differential scanning calorimetry in an attempt to further unravel the complex mechanisms of desiccation tolerance. Melting transitions of water were not observed at water content (wc) values less than 0.21 (T. latifolia) and 0.26 (Z. mays) g H2O/g dry weight. At moisture levels at which melting transitions were not observable, water properties could be characterized by changes in heat capacity. Three hydration regions could be distinguished with the defining wc values changing as a function of temperature. Shifts in baseline power resembling second-order transitions were observed in both species and were interpreted as glass-to-liquid transitions, the glass-transition temperatures being dependent on wc. Irrespective of the extent of desiccation tolerance, both pollens exhibited similar state diagrams. The viability of maize pollen at room temperature decreased gradually with the removal of the unfrozen water fraction. In maize, viability was completely lost before grains were sufficiently dried to enter into a glassy state. Apparently, the glassy state per se cannot provide desiccation tolerance. From the existing data, we conclude that, although no major differences in the physical behavior of water could be distinguished between desiccation-tolerant and -intolerant pollens, the physiological response to the loss of water varies between the two pollen types. PMID:12226289

  9. Molecular Strategies of the Caenorhabditis elegans Dauer Larva to Survive Extreme Desiccation

    PubMed Central

    Erkut, Cihan; Vasilj, Andrej; Boland, Sebastian; Habermann, Bianca; Shevchenko, Andrej; Kurzchalia, Teymuras V.

    2013-01-01

    Massive water loss is a serious challenge for terrestrial animals, which usually has fatal consequences. However, some organisms have developed means to survive this stress by entering an ametabolic state called anhydrobiosis. The molecular and cellular mechanisms underlying this phenomenon are poorly understood. We recently showed that Caenorhabditis elegans dauer larva, an arrested stage specialized for survival in adverse conditions, is resistant to severe desiccation. However, this requires a preconditioning step at a mild desiccative environment to prepare the organism for harsher desiccation conditions. A systems approach was used to identify factors that are activated during this preconditioning. Using microarray analysis, proteomics, and bioinformatics, genes, proteins, and biochemical pathways that are upregulated during this process were identified. These pathways were validated via reverse genetics by testing the desiccation tolerances of mutants. These data show that the desiccation response is activated by hygrosensation (sensing the desiccative environment) via head neurons. This leads to elimination of reactive oxygen species and xenobiotics, expression of heat shock and intrinsically disordered proteins, polyamine utilization, and induction of fatty acid desaturation pathway. Remarkably, this response is specific and involves a small number of functional pathways, which represent the generic toolkit for anhydrobiosis in plants and animals. PMID:24324795

  10. Extracellular superoxide production, viability and redox poise in response to desiccation in recalcitrant Castanea sativa seeds.

    PubMed

    Roach, Thomas; Beckett, Richard P; Minibayeva, Farida V; Colville, Louise; Whitaker, Claire; Chen, Hongying; Bailly, Christophe; Kranner, Ilse

    2010-01-01

    Reactive oxygen species (ROS) are implicated in seed death following dehydration in desiccation-intolerant 'recalcitrant' seeds. However, it is unknown if and how ROS are produced in the apoplast and if they play a role in stress signalling during desiccation. We studied intracellular damage and extracellular superoxide (O(2)(.-)) production upon desiccation in Castanea sativa seeds, mechanisms of O(2)(.-) production and the effect of exogenously supplied ROS. A transient increase in extracellular O(2)(.-) production by the embryonic axes preceded significant desiccation-induced viability loss. Thereafter, progressively more oxidizing intracellular conditions, as indicated by a significant shift in glutathione half-cell reduction potential, accompanied cell and axis death, coinciding with the disruption of nuclear membranes. Most hydrogen peroxide (H(2)O(2))-dependent O(2)(.-) production was found in a cell wall fraction that contained extracellular peroxidases (ECPOX) with molecular masses of approximately 50 kDa. Cinnamic acid was identified as a potential reductant required for ECPOX-mediated O(2)(.-) production. H(2)O(2), applied exogenously to mimic the transient ROS burst at the onset of desiccation, counteracted viability loss of sub-lethally desiccation-stressed seeds and of excised embryonic axes grown in tissue culture. Hence, extracellular ROS produced by embryonic axes appear to be important signalling components involved in wound response, regeneration and growth.

  11. Molecular strategies of the Caenorhabditis elegans dauer larva to survive extreme desiccation.

    PubMed

    Erkut, Cihan; Vasilj, Andrej; Boland, Sebastian; Habermann, Bianca; Shevchenko, Andrej; Kurzchalia, Teymuras V

    2013-01-01

    Massive water loss is a serious challenge for terrestrial animals, which usually has fatal consequences. However, some organisms have developed means to survive this stress by entering an ametabolic state called anhydrobiosis. The molecular and cellular mechanisms underlying this phenomenon are poorly understood. We recently showed that Caenorhabditis elegans dauer larva, an arrested stage specialized for survival in adverse conditions, is resistant to severe desiccation. However, this requires a preconditioning step at a mild desiccative environment to prepare the organism for harsher desiccation conditions. A systems approach was used to identify factors that are activated during this preconditioning. Using microarray analysis, proteomics, and bioinformatics, genes, proteins, and biochemical pathways that are upregulated during this process were identified. These pathways were validated via reverse genetics by testing the desiccation tolerances of mutants. These data show that the desiccation response is activated by hygrosensation (sensing the desiccative environment) via head neurons. This leads to elimination of reactive oxygen species and xenobiotics, expression of heat shock and intrinsically disordered proteins, polyamine utilization, and induction of fatty acid desaturation pathway. Remarkably, this response is specific and involves a small number of functional pathways, which represent the generic toolkit for anhydrobiosis in plants and animals.

  12. Metabolic profiling of the resurrection plant Haberlea rhodopensis during desiccation and recovery.

    PubMed

    Moyankova, Daniela; Mladenov, Petko; Berkov, Strahil; Peshev, Darin; Georgieva, Desislava; Djilianov, Dimitar

    2014-12-01

    Desiccation tolerance is among the most important parameters for crop improvement under changing environments. Resurrection plants are useful models for both theoretical and practical studies. We performed metabolite profiling via gas chromatography coupled with mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) and analyzed the antioxidant capacity of the endemic resurrection plant Haberlea rhodopensis at desiccation and recovery. More than 100 compounds were evaluated. Stress response included changes in both primary and secondary metabolic pathways. The high amounts of the specific glycoside myconoside and some phenolic acids - e.g. syringic and dihydrocaffeic acid under normal conditions tend to show their importance for the priming of H. rhodopensis to withstand severe desiccation and oxidative stress. The accumulation of sucrose (resulting from starch breakdown), total phenols, β-aminoisobutyric acid, β-sitosterol and α-tocopherol increased up to several times at later stages of desiccation. Extracts of H. rhodopensis showed high antioxidant capacity at stress and normal conditions. Myconoside was with the highest antioxidant properties among tested phenolic compounds. Probably, the evolution of resurrection plants under various local environments has resulted in unique desiccation tolerance with specific metabolic background. In our case, it includes the accumulation of a relatively rare compound (myconoside) that contributes alone and together with other common metabolites. Further systems biology studies on the involvement of carbohydrates, phenolic acids and glycosides in the desiccation tolerance and antioxidant capacity of H. rhodopensis will definitely help in achieving the final goal - improving crop drought tolerance.

  13. Photosynthetic recovery following desiccation of desert green algae (Chlorophyta) and their aquatic relatives.

    PubMed

    Gray, Dennis W; Lewis, Louise A; Cardon, Zoe G

    2007-10-01

    Recent molecular data suggest that desert green algae have evolved from freshwater ancestors at least 14 times in three major classes (Chlorophyceae, Trebouxiophyceae and Charophyceae), offering a unique opportunity to study the adaptation of photosynthetic organisms to life on land in a comparative phylogenetic framework. We examined the photorecovery of phylogenetically matched desert and aquatic algae after desiccation in darkness and under illumination. Desert algae survived desiccation for at least 4 weeks when dried in darkness, and recovered high levels of photosynthetic quantum yield within 1 h of rehydration in darkness. However, when 4 weeks of desiccation was accompanied by illumination, three of six desert taxa lost their ability to recover quantum yield during rehydration in the dark. Aquatic algae, in contrast, recovered very little during dark rehydration following even just 24 h of desiccation. Re-illuminating rehydrated algae produced a nearly complete recovery of quantum yield in all desert and two of five aquatic taxa. These contrasts provide physiological evidence that desert green algae possess mechanisms for photosynthetic recovery after desiccation distinct from those in aquatic relatives, corroborating molecular evidence that they are not happenstance, short-term visitors from aquatic environments. Photosensitivity during desiccation among desert algae further suggests that they may reside in protected microsites within crusts, and species specificity of photosensitivity suggests that disturbances physically disrupting crusts could lead to shifts or losses of taxonomic diversity within these habitats.

  14. Time-dependent Cooling in Photoionized Plasma

    NASA Astrophysics Data System (ADS)

    Gnat, Orly

    2017-02-01

    I explore the thermal evolution and ionization states in gas cooling from an initially hot state in the presence of external photoionizing radiation. I compute the equilibrium and nonequilibrium cooling efficiencies, heating rates, and ion fractions for low-density gas cooling while exposed to the ionizing metagalactic background radiation at various redshifts (z = 0 ‑ 3), for a range of temperatures (108–104 K), densities (10‑7–103 cm‑3), and metallicities (10‑3–2 times solar). The results indicate the existence of a threshold ionization parameter, above which the cooling efficiencies are very close to those in photoionization equilibrium (so that departures from equilibrium may be neglected), and below which the cooling efficiencies resemble those in collisional time-dependent gas cooling with no external radiation (and are thus independent of density).

  15. Alfvén wave phase-mixing in flows. Why over-dense, solar coronal, open magnetic field structures are cool

    NASA Astrophysics Data System (ADS)

    Tsiklauri, D.

    2016-02-01

    Aims: The motivation for this study is to include the effect of plasma flow in Alfvén wave (AW) damping via phase mixing and to explore the observational implications. Methods: Our magnetohydrodynamic simulations and analytical calculations show that, when a background flow is present, mathematical expressions for the AW damping via phase mixing are modified by the following substitution: CA' (x) → CA' (x) + V0' (x), where CA and V0 are AW phase and the flow speeds, and the prime denotes a derivative in the direction across the background magnetic field. Results: In uniform magnetic fields and over-dense plasma structures, where CA is smaller than in the surrounding plasma, the flow, which is confined to the structure and going in the same direction as the AW, reduces the effect of phase-mixing, because on the edges of the structure CA' and V0' have opposite signs. Thus, the wave damps by means of slower phase-mixing compared to the case without the flow. This is the result of the co-directional flow that reduces the wave front stretching in the transverse direction. Conversely, the counter-directional flow increases the wave front stretching in the transverse direction, therefore making the phase-mixing-induced heating more effective. Although the result is generic and is applicable to different laboratory or astrophysical plasma systems, we apply our findings to addressing the question why over-dense solar coronal open magnetic field structures (OMFS) are cooler than the background plasma. Observations show that the over-dense OMFS (e.g. solar coronal polar plumes) are cooler than surrounding plasma and that, in these structures, Doppler line-broadening is consistent with bulk plasma motions, such as AW. Conclusions: If over-dense solar coronal OMFS are heated by AW damping via phase-mixing, we show that, co-directional with AW, plasma flow in them reduces the phase-mixing induced-heating, thus providing an explanation of why they appear cooler than the

  16. The extraembryonic serosa protects the insect egg against desiccation

    PubMed Central

    Jacobs, Chris G. C.; Rezende, Gustavo L.; Lamers, Gerda E. M.; van der Zee, Maurijn

    2013-01-01

    Insects have been extraordinarily successful in occupying terrestrial habitats, in contrast to their mostly aquatic sister group, the crustaceans. This success is typically attributed to adult traits such as flight, whereas little attention has been paid to adaptation of the egg. An evolutionary novelty of insect eggs is the serosa, an extraembryonic membrane that enfolds the embryo and secretes a cuticle. To experimentally test the protective function of the serosa, we exploit an exceptional possibility to eliminate this membrane by zerknüllt1 RNAi in the beetle Tribolium castaneum. We analyse hatching rates of eggs under a range of humidities and find dramatically decreasing hatching rates with decreasing humidities for serosa-less eggs, but not for control eggs. Furthermore, we show serosal expression of Tc-chitin-synthase1 and demonstrate that its knock-down leads to absence of the serosal cuticle and a reduction in hatching rates at low humidities. These developmental genetic techniques in combination with ecological testing provide experimental evidence for a crucial role of the serosa in desiccation resistance. We propose that the origin of this extraembryonic membrane facilitated the spectacular radiation of insects on land, as did the origin of the amniote egg in the terrestrial invasion of vertebrates. PMID:23782888

  17. Gas-fired desiccant system for retail super center

    SciTech Connect

    Spears, J.W.; Judge, J.

    1997-10-01

    Concerns about indoor air quality have led to increasing outside air requirements that have prompted HVAC system designers to rethink how to handle outside air. The resulting increase in latent load can cause a variety of problems such as uncomfortably high humidity, mold and mildew, sweating ducts and higher energy cost. These problems occur not only in very humid climates but also in moderate climates during the swing season when the sensible load is low and the outside humidity is high. This combined with increasing concern for occupant comfort has led engineers to look for HVAC designs that provide good temperature and humidity control while still providing adequate quantities of outside air ventilation. This article describes the results of a one-year monitored evaluation of a gas-fired desiccant makeup air system used in a Wal-Mart super center. The system provides continuous fresh-air ventilation and independent temperature and humidity control. It also demonstrates the potential for energy savings and reduced first cost of the HVAC system. This approach, investigated by the owners` design team and independently monitored and verified in this Gas Research Institute-funded field study, has proven to be a cost-effective solution to meeting the new ventilation standard.

  18. Proteomics of seed development, desiccation tolerance, germination and vigor.

    PubMed

    Wang, Wei-Qing; Liu, Shu-Jun; Song, Song-Quan; Møller, Ian Max

    2015-01-01

    Proteomics, the large-scale study of the total complement of proteins in a given sample, has been applied to all aspects of seed biology mainly using model species such as Arabidopsis or important agricultural crops such as corn and rice. Proteins extracted from the sample have typically been separated and quantified by 2-dimensional polyacrylamide gel electrophoresis followed by liquid chromatography and mass spectrometry to identify the proteins in the gel spots. In this way, qualitative and quantitative changes in the proteome during seed development, desiccation tolerance, germination, dormancy release, vigor alteration and responses to environmental factors have all been studied. Many proteins or biological processes potentially important for each seed process have been highlighted by these studies, which greatly expands our knowledge of seed biology. Proteins that have been identified to be particularly important for at least two of the seed processes are involved in detoxification of reactive oxygen species, the cytoskeleton, glycolysis, protein biosynthesis, post-translational modifications, methionine metabolism, and late embryogenesis-abundant (LEA) proteins. It will be useful for molecular biologists and molecular plant breeders to identify and study genes encoding particularly interesting target proteins with the aim to improve the yield, stress tolerance or other critical properties of our crop species.

  19. [Prevention of peritoneal desiccation in acute adhesive intestinal obstruction].

    PubMed

    2014-01-01

    The research study was carried out on 30 white Wistar rats, which were divided into three groups. In the first group the effect of carboxyperitoneum on visceral peritoneum during a two hour period at a pressure of 9-10 mm Hg and after 20 minutes its further fractional replacement during 10 seconds was examined. In the second group, the study was carried out after modeling 12-hours acute adhesive intestinal obstruction. To the third group at the beginning was given a single injection of four component mixture (carboxyperitoneum gel carboxymetiltcellulose novocaine and antibiotic) into the abdominal cavity. In the first group under the condition of tension carboxyperitoneum after a day of use there were signs of desiccations of visceral peritoneum. The increase of lipid peroxidation products and decrease of antioxidant enzymes were also observed. In the second group of animals these processes were exacerbated by acute adhesive intestinal obstruction. In the third group intraabdominal use of four component disperse mixture reduced the negative organic and functional changes in visceral peritoneum and improved its protective properties.

  20. X-Ray spectroscopy of cooling flows

    NASA Technical Reports Server (NTRS)

    Prestwich, Andrea

    1996-01-01

    Cooling flows in clusters of galaxies occur when the cooling time of the gas is shorter than the age of the cluster; material cools and falls to the center of the cluster potential. Evidence for short X-ray cooling times comes from imaging studies of clusters and X-ray spectroscopy of a few bright clusters. Because the mass accretion rate can be high (a few 100 solar mass units/year) the mass of material accumulated over the lifetime of a cluster can be as high as 10(exp 12) solar mass units. However, there is little evidence for this material at other wavelengths, and the final fate of the accretion material is unknown. X-ray spectra obtained with the Einstein SSS show evidence for absorption; if confirmed this result would imply that the accretion material is in the form of cool dense clouds. However ice on the SSS make these data difficult to interpret. We obtained ASCA spectra of the cooling flow cluster Abell 85. Our primary goals were to search for multi-temperature components that may be indicative of cool gas; search for temperature gradients across the cluster; and look for excess absorption in the cooling region.