WorldWideScience

Sample records for air warming system

  1. Airborne Asbestos Exposures from Warm Air Heating Systems in Schools.

    Science.gov (United States)

    Burdett, Garry J; Dewberry, Kirsty; Staff, James

    2016-01-01

    The aim of this study was to investigate the concentrations of airborne asbestos that can be released into classrooms of schools that have amosite-containing asbestos insulation board (AIB) in the ceiling plenum or other spaces, particularly where there is forced recirculation of air as part of a warm air heating system. Air samples were collected in three or more classrooms at each of three schools, two of which were of CLASP (Consortium of Local Authorities Special Programme) system-built design, during periods when the schools were unoccupied. Two conditions were sampled: (i) the start-up and running of the heating systems with no disturbance (the background) and (ii) running of the heating systems during simulated disturbance. The simulated disturbance was designed to exceed the level of disturbance to the AIB that would routinely take place in an occupied classroom. A total of 60 or more direct impacts that vibrated and/or flexed the encapsulated or enclosed AIB materials were applied over the sampling period. The impacts were carried out at the start of the sampling and repeated at hourly intervals but did not break or damage the AIB. The target air volume for background samples was ~3000 l of air using a static sampler sited either below or ~1 m from the heater outlet. This would allow an analytical sensitivity (AS) of 0.0001 fibres per millilitre (f ml(-1)) to be achieved, which is 1000 times lower than the EU and UK workplace control limit of 0.1 f ml(-1). Samples with lower volumes of air were also collected in case of overloading and for the shorter disturbance sampling times used at one site. The sampler filters were analysed by phase contrast microscopy (PCM) to give a rapid determination of the overall concentration of visible fibres (all types) released and/or by analytical transmission electron microscopy (TEM) to determine the concentration of asbestos fibres. Due to the low number of fibres, results were reported in terms of both the calculated

  2. Forced-Air Warming During Pediatric Surgery: A Randomized Comparison of a Compressible with a Noncompressible Warming System.

    Science.gov (United States)

    Triffterer, Lydia; Marhofer, Peter; Sulyok, Irene; Keplinger, Maya; Mair, Stefan; Steinberger, Markus; Klug, Wolfgang; Kimberger, Oliver

    2016-01-01

    Perioperative hypothermia is a common problem, challenging the anesthesiologist and influencing patient outcome. Efficient and safe perioperative active warming is therefore paramount; yet, it can be particularly challenging in pediatric patients. Forced-air warming technology is the most widespread patient-warming option, with most forced-air warming systems consisting of a forced-air blower connected to a compressible, double layer plastic and/or a paper blanket with air holes on the patient side. We compared an alternative, forced-air, noncompressible, under-body patient-warming mattress (Baby/Kleinkinddecke of MoeckWarmingSystems, Moeck und Moeck GmbH; group MM) with a standard, compressible warming mattress system (Pediatric Underbody, Bair Hugger, 3M; group BH). The study included 80 patients aged surgery. After a preoperative core temperature measurement, the patients were placed on the randomized mattress in the operation theater and 4 temperature probes were applied rectally and to the patients' skin. The warming devices were turned on as soon as possible to the level for pediatric patients as recommended by the manufacturer (MM = 40°C, BH = 43°C). There was a distinct difference of temperature slope between the 2 groups: core temperatures of patients in the group MM remained stable and mean of the core temperature of patients in the group BH increased significantly (difference: +1.48°C/h; 95% confidence interval, 0.82-2.15°C/h; P = 0.0001). The need for temperature downregulation occurred more often in the BH group, with 22 vs 7 incidences (RR, 3.14; 95% confidence interval, 1.52-6.52; P = 0.0006). Skin temperatures were all lower in the MM group. Perioperatively, no side effects related to a warming device were observed in any group. Both devices are feasible choices for active pediatric patient warming, with the compressible mattress system being better suited to increase core temperature. The use of lower pediatric forced-air temperature settings

  3. 'TEWI' concept for estimation of the global warming from the refrigerating and air conditioning systems

    International Nuclear Information System (INIS)

    Ciconkov, Risto

    2002-01-01

    The most applied CFC refrigerants and their HFC alternatives. values of ODP (Ozone Depletion Potential) and GWP (Global Warming Potential) of the most used refrigerants. natural working fluids and their properties. Montreal Protocol and Kyoto Protocol, illogical relations between them concerning to the HFC fluids. Confusion and polemics on the international level about the appliance of HFCs which, by the Kyoto Protocol, are liable to reduction. Introduction of the TEWI concept as a method for estimating the overall influence of refrigerating and air conditioning systems on the greenhouse effect: the direct emission (refrigerant leakage in the atmosphere) and indirect emission as a result of the electrical energy consumption. A demonstration of the TEWI concept on the concrete example in several variants. A discussion about the appliance of the TEWI concept. Meaning of the energy efficiency of the refrigerating systems (indirect CO 2 emission). One of the main measures: prevention of refrigerant leakage (direct CO 2 emission). A need of permanent education and training courses of the people who work on refrigerating and air conditioning systems. A necessity for constitution of an expert body in the country, preparation of a strategy to lay obligations on the new changes of the Kyoto Protocol and news on the world market. Introduction of country regulations, certification of the companies and people involved in refrigeration and air conditioning. (Author)

  4. Next Generation Refrigeration Lubricants for Low Global Warming Potential/Low Ozone Depleting Refrigeration and Air Conditioning Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hessell, Edward Thomas [Chemtura Corporation, Middlebury, CT (United States)

    2013-12-31

    The goal of this project is to develop and test new synthetic lubricants that possess high compatibility with new low ozone depleting (LOD) and low global warming potential (LGWP) refrigerants and offer improved lubricity and wear protection over current lubricant technologies. The improved compatibility of the lubricants with the refrigerants, along with improved lubricating properties, will resulted in lower energy consumption and longer service life of the refrigeration systems used in residential, commercial and industrial heating, ventilating and air-conditioning (HVAC) and refrigeration equipment.

  5. Air distribution and ventilation effectiveness in an occupied room heated by warm air

    DEFF Research Database (Denmark)

    Krajcik, Michal; Simone, Angela; Olesen, Bjarne W.

    2012-01-01

    . Contaminant removal effectiveness and air change efficiency were used to evaluate ventilation effectiveness. No significant risk of thermal discomfort due to vertical air temperature differences or draught was found. When the room was heated by warm air, buoyancy forces were important for ventilation......Air distribution, ventilation effectiveness and thermal environment were experimentally studied in a simulated room in a low-energy building heated and ventilated by warm air supplied by a mixing ventilation system. Measurements were performed for various positions of the air terminal devices...... and at different simulated outside conditions, internal heat gains and air change rates. Floor heating was also simulated and compared with the warm air heating system. Vertical air temperature profiles, air velocity profiles and equivalent temperatures were derived in order to describe the thermal environment...

  6. Can air pollutant controls change global warming?

    International Nuclear Information System (INIS)

    Strefler, Jessica; Luderer, Gunnar; Kriegler, Elmar; Meinshausen, Malte

    2014-01-01

    Highlights: • Air pollution policies do not affect long-term climate targets. • Reduction of aerosols counteracts a fraction of the reduction of Kyoto forcing. • Air pollution policies may affect the rate of climate change in the short term. • There is no tradeoff between clean air and climate policies. - Abstract: In this paper we analyze the interaction between climate and air pollution policies using the integrated assessment model REMIND coupled to the reduced-form climate model MAGICC. Since overall, aerosols tend to cool the atmosphere, there is a concern that a reduction of pollutant emissions could accelerate global warming and offset the climate benefits of carbon dioxide emission reductions. We investigate scenarios which independently reduce emissions from either large-scale sources, such as power plants, or small-scale sources, such as cooking and heating stoves. Large-scale sources are likely to be easier to control, but their aerosol emissions are characterized by a relatively high sulfur content, which tends to result in atmospheric cooling. Pollution from small-scale sources, by contrast, is characterized by a high share of carbonaceous aerosol, which is an important contributor to global warming. We find that air pollution policies can significantly reduce aerosol emissions when no climate policies are in place. Stringent climate policies lead to a large reduction of fossil fuel use, and therefore result in a concurrent reduction of air pollutant emissions. These reductions partly reduce aerosol masking, thus initially counteracting the reduction of greenhouse gas forcing, however not overcompensating it. If climate policies are in place, air pollution policies have almost no impacts on medium- and long-term radiative forcing. Therefore there is no conflict of objectives between clean air and limiting global warming. We find that the stringency of air pollution policies may influence the rate of global temperature change in the first decade

  7. Effects of warming on uptake and translocation of cadmium (Cd) and copper (Cu) in a contaminated soil-rice system under Free Air Temperature Increase (FATI).

    Science.gov (United States)

    Ge, Li-Qiang; Cang, Long; Liu, Hui; Zhou, Dong-Mei

    2016-07-01

    Global warming has received growing attentions about its potential threats to human in recent, however little is known about its effects on transfer of heavy metals in agro-ecosystem, especially for Cd in rice. Pot experiments were conducted to evaluate Cd/Cu translocation in a contaminated soil-rice system under Free Air Temperature Increase (FATI). The results showed that warming gradually decreased soil porewater pH and increased water-soluble Cd/Cu concentration, reduced formation of iron plaque on root surface, and thus significantly increased total uptake of Cd/Cu by rice. Subsequently, warming significantly promoted Cd translocation from root to shoot, and increased Cd distribution percentage in shoot, while Cu was not significantly affected. Enhanced Cd uptake and translocation synergistically resulted in higher rice grain contamination with increasing concentration from 0.27 to 0.65 and 0.14-0.40 mg kg(-1) for Indica and Japonica rice, respectively. However increase of Cu in brown grain was only attributed to its uptake enhancement under warming. Our study provides a new understanding about the food production insecurity of heavy metal contaminated soil under the future global warming. Copyright © 2016. Published by Elsevier Ltd.

  8. Comparison of a radiant patient warming device with forced air warming during laparoscopic cholecystectomy.

    Science.gov (United States)

    Wong, A; Walker, S; Bradley, M

    2004-02-01

    The importance of maintaining a patient's core body temperature during anaesthesia to reduce the incidence of postoperative complications has been well documented. The standard practice of this institution is the use of a forced air device for intraoperative warming. The purpose of this study was to compare this standard with an alternative warming device using a radiant heat source which only heated the face. This prospective, randomized controlled trial compared the efficacy of two methods of intraoperative warming: the BairHugger (Augustine Medical, U.S.A.) forced air device and the SunTouch (Fisher & Paykel Healthcare, N.Z.) radiant warmer during laparoscopic cholecystectomy in 42 female patients. Oesophageal core temperatures were recorded automatically on to computer during operations using standardised anaesthesia, intravenous infusions and draping. The study failed to show any statistical or clinical difference between the two patient groups in terms of mean core temperature both intraoperatively (P = 0.42) and in the recovery period (P = 0.54). Mean start to end core temperature differences were marginally lower in the radiant group (0.08 degree C) but not statistically or clinically significantly different. Given some of the drawbacks with forced air systems, such as the expense of the single use blanket, this new radiant warming device offers an alternative method of active warming with advantages in terms of cost and possible application to a wide variety of surgical procedures.

  9. A linkage with air pollution and global warming

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-29

    Dec 29, 2009 ... Various forest declines and forest health conditions have been described for forest ecosystems throughout the world. The connection to global warming and air pollution is clear in some area, but not in others. In this study, some evidences that support or contradict air pollution and global warming.

  10. Study on heat collector of the solar system utilizing outdoor air. Experimental results in cases of cold and warm regions; Gaiki donyushiki solar system no shunetsubu ni kansuru kenkyu. Kanreichi to ondanchi ni okeru shunetsu jikken to kosatsu

    Energy Technology Data Exchange (ETDEWEB)

    Komano, S.; Ebara, Y. [OM Solar Association, Shizuoka (Japan); Wada, H. [Wada Building Constructors Co. Ltd., Hokkaido (Japan)

    1996-10-27

    An experiment on heat collection was made in the heat collector of a solar system utilizing outdoor air in cold and warm regions. In this system, outdoor air is heated by the air circulation layer on the roof exposed to solar radiation. The heated air is supplied to the object space for heating and ventilation. In the experiment in a cold region, the heat collection characteristics can be adjusted by putting a baffle plate in the air duct according to the experiment of a glass heat collector. The heat collecting air layer on only the iron roof may leak or freeze in the region subject to coldness or heavy snowfall. Therefore, preheat forms the space of a garret, and the preheat temperature comparatively becomes low. The data in which the heat collection characteristics can be adjusted using only a glass heat collector is required corresponding to the regional situation. In the experiment in a warm region, an experiment was made inclusive of the preheat for which outdoor air is absorbed at the eaves. As a result, the heat collection characteristics of preheat were improved. Moreover, a heat collection temperature of about 60{degree}C was obtained on the heat collection surface including the preheat. 1 ref., 12 figs., 3 tabs.

  11. Preferred Air Velocity and Local Cooling Effect of desk fans in warm environments

    DEFF Research Database (Denmark)

    Simone, Angela; Olesen, Bjarne W.

    2013-01-01

    Common experiences, standards, and laboratory studies show that increased air velocity helps to offset warm sensation due to high environmental temperatures. In warm climate regions the opening of windows and the use of desk or ceiling fans are the most common systems to generate increased airflows...... to compensate for higher environmental temperatures at the expense of no or relatively low energy consumption. When using desk fans, local air movement is generated around the occupant and a certain cooling effect is perceived. The impact of the local air movement generated by different air flow patterns....../kg. By a thermal manikin the effect of direct air movement generated by a personal desk fan at 26 °C, 28 °C, or 30 °C room temperatures and the achievable thermal comfort was also analyzed. Results show that it is possible to offset warm sensation within a range of indoor conditions using increased air velocity...

  12. Forced-air warming discontinued: periprosthetic joint infection rates drop

    Directory of Open Access Journals (Sweden)

    Scott D. Augustine

    2017-06-01

    Full Text Available Several studies have shown that the waste heat from forced-air warming (FAW escapes near the floor and warms the contaminated air resident near the floor. The waste heat then forms into convection currents that rise up and contaminate the sterile field above the surgical table. It has been shown that a single airborne bacterium can cause a periprosthetic joint infection (PJI following joint replacement surgery. We retrospectively compared PJI rates during a period of FAW to a period of air-free conductive fabric electric warming (CFW at three hospitals. Surgical and antibiotic protocols were held constant. The pooled multicenter data showed a decreased PJI rate of 78% following the discontinuation of FAW and a switch to air-free CFW (n=2034; P=0.002. The 78% reduction in joint implant infections observed when FAW was discontinued suggests that there is a link between the waste FAW heat and PJIs.

  13. Prediction of thermal sensation in non-air-conditioned buildings in warm climates

    DEFF Research Database (Denmark)

    Fanger, Povl Ole; Toftum, Jørn

    2002-01-01

    The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV...... predicts. The main reason is low expectations, but a metabolic rate that is estimated too high can also contribute to explaining the difference. An extension of the PMV model that includes an expectancy factor is introduced for use in non-air-conditioned buildings in warm climates. The extended PMV model...... agrees well with quality field studies in non-air-conditioned buildings of three continents....

  14. Extension of the PMV model to non-air-conditioned building in warm climates

    DEFF Research Database (Denmark)

    Fanger, Povl Ole; Toftum, Jørn

    2002-01-01

    predicts. The main reason is low expectations, but a metabolic rate that is estimated too high can also contribute to explaining the difference. An extension of the PMV model that includes an expectancy factor is introduced for use in non-air-conditioned buildings in warm climates. The extended PMV model......The PMV model agrees well with high-quality field studies in buildings with HVAC systems, situated in cold, temperate and warm climates, studied during both summer and winter. In non-air-conditioned buildings in warm climates, occupants may sense the warmth as being less severe than the PMV...... agrees well with quality field studies in non-air-conditioned buildings of three continents....

  15. MICROBIOLOGICAL CHARACTERISTICS OF THE AIR BLOWN BY WARM AIR HAND DRYERS

    Directory of Open Access Journals (Sweden)

    Recai OÐUR; Omer Faruk TEKBAS; Osman HANCI; Umut OZCAN

    2005-02-01

    Full Text Available The aim of the study was to determine the microbiological characteristics of air blown from warm air hand dryers, and to compare findings with the microbiological characteristics of indoor air in which the dryer settled. Air samples was taken from different public places (shopping centers, restaurants and hospitals and investigated for total viable counts, coagulase negative Staphylococcus, E. Coli, Staphylococcus aureus and enteric pathogens. There were differences between sampling indoor places for some of the microorganisms, but all of the air samples taken from dryers contained more microorganisms than indoor air, and the differences between hand dryers and indoor air were statistically significant (p<0.05 except for enteric pathogens. As a result it could be said that warm air hand dryers could be microbiological contamination sources in restrooms or the other places that they are used. [TAF Prev Med Bull 2005; 4(1.000: 1-7

  16. Global warming potential impact of bioenergy systems

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, L.; Wenzel, H.

    environmental consequences related to land use changes. In this study the global warming potential impact associated with six alternative bioenergy systems based on willow and Miscanthus was assessed by means of life-cycle assessment. The results showed that bioenergy production may generate higher global...... warming impacts than the reference fossil fuel system, when the impacts from indirect land use changes are accounted for. In a life-cycle perspective, only highly-efficient co-firing with fossil fuel achieved a (modest) GHG emission reduction....

  17. Air Quality System (AQS)

    Science.gov (United States)

    The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements include both criteria air pollutants and hazardous air pollutants.

  18. Microclimatic performance of a free-air warming and CO2 enrichment experiment in windy Wyoming, USA.

    Directory of Open Access Journals (Sweden)

    Daniel LeCain

    Full Text Available In order to plan for global changing climate experiments are being conducted in many countries, but few have monitored the effects of the climate change treatments (warming, elevated CO2 on the experimental plot microclimate. During three years of an eight year study with year-round feedback-controlled infra-red heater warming (1.5/3.0°C day/night and growing season free-air CO2 enrichment (600 ppm in the mixed-grass prairie of Wyoming, USA, we monitored soil, leaf, canopy-air, above-canopy-air temperatures and relative humidity of control and treated experimental plots and evaluated ecologically important temperature differentials. Leaves were warmed somewhat less than the target settings (1.1 & 1.5°C day/night but soil was warmed more creating an average that matched the target settings extremely well both during the day and night plus the summer and winter. The site typically has about 50% bare or litter covered soil, therefore soil heat transfer is more critical than in dense canopy ecosystems. The Wyoming site commonly has strong winds (5 ms(-1 average and significant daily and seasonal temperature fluctuations (as much as 30°C daily but the warming system was nearly always able to maintain the set temperatures regardless of abiotic variation. The within canopy-air was only slightly warmed and above canopy-air was not warmed by the system, therefore convective warming was minor. Elevated CO2 had no direct effect nor interaction with the warming treatment on microclimate. Relative humidity within the plant canopy was only slightly reduced by warming. Soil water content was reduced by warming but increased by elevated CO2. This study demonstrates the importance of monitoring the microclimate in manipulative field global change experiments so that critical physiological and ecological conclusions can be determined. Highly variable energy demand fluctuations showed that passive IR heater warming systems will not maintain desired warming for

  19. Microclimatic Performance of a Free-Air Warming and CO2 Enrichment Experiment in Windy Wyoming, USA

    Science.gov (United States)

    LeCain, Daniel; Smith, David; Morgan, Jack; Kimball, Bruce A.; Pendall, Elise; Miglietta, Franco

    2015-01-01

    In order to plan for global changing climate experiments are being conducted in many countries, but few have monitored the effects of the climate change treatments (warming, elevated CO2) on the experimental plot microclimate. During three years of an eight year study with year-round feedback-controlled infra-red heater warming (1.5/3.0°C day/night) and growing season free-air CO2 enrichment (600 ppm) in the mixed-grass prairie of Wyoming, USA, we monitored soil, leaf, canopy-air, above-canopy-air temperatures and relative humidity of control and treated experimental plots and evaluated ecologically important temperature differentials. Leaves were warmed somewhat less than the target settings (1.1 & 1.5°C day/night) but soil was warmed more creating an average that matched the target settings extremely well both during the day and night plus the summer and winter. The site typically has about 50% bare or litter covered soil, therefore soil heat transfer is more critical than in dense canopy ecosystems. The Wyoming site commonly has strong winds (5 ms-1 average) and significant daily and seasonal temperature fluctuations (as much as 30°C daily) but the warming system was nearly always able to maintain the set temperatures regardless of abiotic variation. The within canopy-air was only slightly warmed and above canopy-air was not warmed by the system, therefore convective warming was minor. Elevated CO2 had no direct effect nor interaction with the warming treatment on microclimate. Relative humidity within the plant canopy was only slightly reduced by warming. Soil water content was reduced by warming but increased by elevated CO2. This study demonstrates the importance of monitoring the microclimate in manipulative field global change experiments so that critical physiological and ecological conclusions can be determined. Highly variable energy demand fluctuations showed that passive IR heater warming systems will not maintain desired warming for much of the

  20. Global warming potential impact of bioenergy systems

    Directory of Open Access Journals (Sweden)

    Wenzel H.

    2012-10-01

    Full Text Available Reducing dependence on fossil fuels and mitigation of GHG emissions is a main focus in the energy strategy of many Countries. In the case of Demark, for instance, the long-term target of the energy policy is to reach 100% renewable energy system. This can be achieved by drastic reduction of the energy demand, optimization of production/distribution and substitution of fossil fuels with biomasses. However, a large increase in biomass consumption will finally induce conversion of arable and currently cultivated land into fields dedicated to energy crops production determining significant environmental consequences related to land use changes. In this study the global warming potential impact associated with six alternative bioenergy systems based on willow and Miscanthus was assessed by means of life-cycle assessment. The results showed that bioenergy production may generate higher global warming impacts than the reference fossil fuel system, when the impacts from indirect land use changes are accounted for. In a life-cycle perspective, only highly-efficient co-firing with fossil fuel achieved a (modest GHG emission reduction.

  1. Tropical Intraseasonal Air-Sea Exchanges during the 1997 Pacific Warming

    Science.gov (United States)

    Sui, C.-H.; Lau, K.-M.; Chou, S.-H.; Wang, Zihou

    1999-01-01

    The Madden Julian Oscillations (MJO) and associated westerly wind (WW) events account for much of the tropical intraseasonal variability (TISV). The TISV has been suggested as an important stochastic forcing that may be one of the underlying causes for the observed irregularities of the El Nino-Southern Oscillation (ENSO). Recent observational studies and theories of interannual to interdecadal-scale variability suggest that ENSO may arise from different mechanisms depending on the basic states. The Pacific warming event of 1997, being associated with a period of strong MJO and WW events, serves as a natural experiment for studying the possible role of TISV in triggering an ENSO event. We have performed a combined statistical and composite analysis of surface WW events based on the assimilated surface wind and sea level pressure for the period of 1980-1993, the SSM/I wind for the period of 1988-1997, and OLR. Results indicates that extratropical forcing contribute significantly to the evolution of MJO and establishment of WW events over the Pacific warm pool. Following the major WW events, there appeared an eastward extension of equatorial warm SST anomalies from the western Pacific warm pool. Such tropical-extratropical interaction is particularly clear in the winter of 96-97 that leads to the recent warming event in 1997/98. From the above discussion, our current study on this subject is based on the hypothesis that 1) there is an enhanced air-sea interaction associated with TISV and the northerly surges from the extratropics in the initial phase of the 97/98 warming event, and 2) the relevant mechanisms are functions of the basic state of the coupled system (in terms of SST distribution and atmospheric mean circulation) that varies at the interannual and interdecadal time scale. We are analyzing the space-time structure of the northerly surges, their association with air-sea fluxes and upper ocean responses during the period of September 1996 to June 1997. The

  2. Provenance-specific growth responses to drought and air warming in three European oak species

    Energy Technology Data Exchange (ETDEWEB)

    Arend, Matthias; Kuster, Thomas; Gunthardt-Goerg, Madeleine S.; Dobbertin, Matthias

    2011-03-15

    This study evaluated oak growth responses to air warming through research conducted with species coming from climatically different sites submitted to differing climates including periodic drought and air warming. Results showed different responses to drought and air warming as an adaptation to the conditions, and differences in growth response from one provenance to another were found but local climate factors were not responsible. This study highlighted that provenance was important to growth responses and it will have to be taken into account for regeneration of oaks in a changed climate if these results are confirmed.

  3. Effectiveness of cutaneous warming systems on temperature control: meta-analysis.

    Science.gov (United States)

    Galvão, Cristina Maria; Liang, Yuanyuan; Clark, Alexander M

    2010-06-01

    This paper is a report of a meta-analysis to identify the effectiveness of different types of cutaneous warming systems in temperature control for patients undergoing elective surgery. Hypothermia is a common and serious complication of surgery. Different cutaneous warming systems are used to prevent hypothermia during surgery but there have been no previous meta-analyses of the effectiveness of different warming systems in controlling temperature. We conducted a search of the CINAHL (2000 to April 2009), Medline (2000 to April 2009), Embase (2000 to April 2009) and the Cochrane Register of Controlled Trials (2000 to April 2009) databases for randomized controlled trials published in English, Spanish and Portuguese. The primary outcome measure of interest was core body temperature. A systematic review incorporating meta-analysis was carried out. From 329 papers, 23 trials compared warming systems. Forced-air warming systems had a strong tendency towards superior temperature control over passive insulation via cotton blankets (mean difference: 0.29 degrees C; 95% confidence interval: -0.02 to 0.59, three trials 292 patients) and radiant warming systems (mean difference: 0.16 degrees C; 95% confidence interval: -0.01 to 0.33, three trials, 161 patients). However, circulating water garments tended to be more effective than forced-air warming systems (mean difference: -0.73 degrees C; 95% confidence interval: -1.51 to 0.05, I(2) = 97%; four trials, 198 patients). Pooled results approached statistical significance and indicated clinically meaningful differences in temperature control. Current evidence suggests that circulating water garments offer better temperature control than forced-air warming systems, and both are more effective than passive warming devices.

  4. Air Quality System (AQS)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Air Quality System (AQS) database contains measurements of air pollutant concentrations from throughout the United States and its territories. The measurements...

  5. Global warming potential impact of bioenergy systems

    DEFF Research Database (Denmark)

    Tonini, Davide; Hamelin, L.; Wenzel, H.

    of the energy demand, optimization of production/distribution and substitution of fossil fuels with biomasses. However, a large increase in biomass consumption will finally induce conversion of arable and currently cultivated land into fields dedicated to energy crops production determining significant......Reducing dependence on fossil fuels and mitigation of GHG emissions is a main focus in the energy strategy of many Countries. In the case of Demark, for instance, the long-term target of the energy policy is to reach 100% renewable energy system. This can be achieved by drastic reduction...... warming impacts than the reference fossil fuel system, when the impacts from indirect land use changes are accounted for. In a life-cycle perspective, only highly-efficient co-firing with fossil fuel achieved a (modest) GHG emission reduction....

  6. Effects of experimental warming of air, soil and permafrost on carbon balance in Alaskan tundra

    Science.gov (United States)

    S.M. Natali; E.A.G. Schuur; C. Trucco; C.E. Hicks Pries; K.G. Crummer; A.F. Baron Lopez

    2011-01-01

    The carbon (C) storage capacity of northern latitude ecosystems may diminish as warming air temperatures increase permafrost thaw and stimulate decomposition of previously frozen soil organic C. However, warming may also enhance plant growth so that photosynthetic carbon dioxide (C02) uptake may, in part, offset respiratory losses. To determine...

  7. Comparison of global warming impacts of automobile air-conditioning concepts

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The global warming impacts of conventional vapor compression automobile air conditioning using HFC-134a are compared with the potential impacts of four alternative concepts. Comparisons are made on the basis of total equivalent warming impact (TEWI) which accounts for the effects of refrigerant emissions, energy use to provide comfort cooling, and fuel consumed to transport the weight of the air conditioning system. Under the most favorable assumptions on efficiency and weight, transcritical compression using CO{sub 2} as the refrigerant and adsorption cooling with water and zeolite beds could reduce TEWI by up to 18%rlative to HFC-134a compression air conditioning. Other assumptions on weight and efficiency lead to significant increases in TEWI relative to HFC-134a, and it is impossible to determine which set of assumptios is valid from existing data, Neither Stirling cycle or thermoelectric cooling will reduce TEWI relative to EFC-134a. Brief comments are also made concerning technical barriers that must be overcome for succesful development of the new technologies.

  8. Effect of warm air supplied facially on occupants' comfort

    DEFF Research Database (Denmark)

    Kaczmarczyk, J.; Melikov, Arsen Krikor; Sliva,, D.

    2010-01-01

    Human response to air movement supplied locally towards the face was studied in a room with an air temperature of 20 °C and a relative humidity of 30%. Thirty-two human subjects were exposed to three conditions: calm environment and facially supplied airflow at 21 °C and at 26 °C. The air was sup...

  9. Comparison of resistive heating and forced-air warming to prevent inadvertent perioperative hypothermia.

    Science.gov (United States)

    John, M; Crook, D; Dasari, K; Eljelani, F; El-Haboby, A; Harper, C M

    2016-02-01

    Forced-air warming is a commonly used warming modality, which has been shown to reduce the incidence of inadvertent perioperative hypothermia (heating mattresses offer a potentially cheaper alternative, however, and one of the research recommendations from the National Institute for Health and Care Excellence was to evaluate such devices formally. We conducted a randomized single-blinded study comparing perioperative hypothermia in patients receiving resistive heating or forced-air warming. A total of 160 patients undergoing non-emergency surgery were recruited and randomly allocated to receive either forced-air warming (n=78) or resistive heating (n=82) in the perioperative period. Patient core temperatures were monitored after induction of anaesthesia until the end of surgery and in the recovery room. Our primary outcome measures included the final intraoperative temperature and incidence of hypothermia at the end of surgery. There was a significantly higher rate of hypothermia at the end of surgery in the resistive heating group compared with the forced-air warming group (P=0.017). Final intraoperative temperatures were also significantly lower in the resistive heating group (35.9 compared with 36.1°C, P=0.029). Hypothermia at the end of surgery in both warming groups was common (36% forced air warming, 54% resistive heating). Our results suggest that forced-air warming is more effective than resistive heating in preventing postoperative hypothermia. NCT01056991. © The Author 2016. Published by Oxford University Press on behalf of the British Journal of Anaesthesia. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. Potential Alternative Lower Global Warming Refrigerants for Air Conditioning in Hot Climates

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL; Shen, Bo [ORNL

    2017-01-01

    The earth continues to see record increase in temperatures and extreme weather conditions that is largely driven by anthropogenic emissions of warming gases such as carbon dioxide and other more potent greenhouse gases such as refrigerants. The cooperation of 188 countries in the Conference of the Parties in Paris 2015 (COP21) resulted in an agreement aimed to achieve a legally binding and universal agreement on climate, with the aim of keeping global warming below 2 C. A global phasedown of hydrofluorocarbons (HFCs) can prevent 0.5 C of warming by 2100. However, most of the countries in hot climates are considered as developing countries and as such are still using R-22 (a Hydrochlorofluorocarbon (HCFC)) as the baseline refrigerant and are currently undergoing a phase-out of R-22 which is controlled by current Montreal Protocol to R-410A and other HFC based refrigerants. These HFCs have significantly high Global Warming Potential (GWP) and might not perform as well as R-22 at high ambient temperature conditions. In this paper we present recent results on evaluating the performance of alternative lower GWP refrigerants for R-22 and R-410A for small residential mini-split air conditioners and large commercial packaged units. Results showed that several of the alternatives would provide adequate replacement for R-22 with minor system modification. For the R-410A system, results showed that some of the alternatives were almost drop-in ready with benefit in efficiency and/or capacity. One of the most promising alternatives for R-22 mini-split unit is propane (R-290) as it offers higher efficiency; however it requires compressor and some other minor system modification to maintain capacity and minimize flammability risk. Between the R-410A alternatives, R-32 appears to have a competitive advantage; however at the cost of higher compressor discharge temperature. With respect to the hydrofluoroolefin (HFO) blends, there existed a tradeoff in performance and system design

  11. Spherical warm shield design for infrared imaging systems

    Science.gov (United States)

    Tian, Qijie; Chang, Songtao; He, Fengyun; Li, Zhou; Qiao, Yanfeng

    2017-09-01

    The F-number matching is the primary means to suppress stray radiation for infrared imaging systems. However, it is difficult to achieve exact F-number matching, owing to the restriction from detectors, or multiple F-number design. Hence, an additional shield is required to block the certain thermal radiation. Typical shield is called flat warm shield, which is flat and operates at room temperature. For flat warm shield, it cannot suppress stray radiation while achieving F-number matching. To overcome the restriction, a spherical reflective warm shield is required. First of all, the detailed theory of spherical warm shield design is developed on basis of the principle that stray radiation cannot directly reach the infrared focal plane array. According to the theory developed above, a polished spherical warm shield, whose radius is 18 mm, is designed to match an F/2 infrared detector with an F/4 infrared imaging system. Then, the performance and alignment errors of the designed spherical warm shield are analyzed by simulation. Finally, a contrast experiment between the designed spherical warm shield and two differently processed flat warm shields is performed in a chamber with controllable inside temperatures. The experimental results indicate that the designed spherical warm shield cannot only achieve F-number matching but suppress stray radiation sufficiently. Besides, it is demonstrated that the theory of spherical warm shield design developed in this paper is valid and can be employed by arbitrary infrared imaging systems.

  12. Air Mass Origin in the Arctic and its Response to Future Warming

    Science.gov (United States)

    Orbe, C.; Newman, P. A.; Waugh, D. W.; Holzer, M. B.; Oman, L.; Polvani, L. M.; Li, F.

    2014-12-01

    Long-range transport from Northern Hemisphere (NH) midlatitudes plays a key role in setting the distributions of trace species and aerosols in the Arctic. While comprehensive models project a strengthening and poleward shift in the midlatitude tropospheric jets in response to future warming, relatively little attention has been paid to assessing the large-scale transport response in the Arctic. A natural way to quantify transport and its future changes is in terms of rigorously defined air masses that partition air according to where it last contacted the planetary boundary layer (PBL). Here we present climatologies of Arctic air mass origin for NH winter and summer, computed from two integrations of the Goddard Earth Observing System chemistry-climate model (GEOSCCM) subject to present-day and future climate forcings. The modeled transport response to A1B greenhouse-gas induced warming reveals that in the future ~10% more air in the Arctic will originate over NH midlatitudes, with a slighter weaker albeit significant increase in winter compared to summer. Our results indicate that transport changes alone may lead to "cleaner" Arctic winters, as air will be 5-10% more likely to have last contacted the PBL over the East Pacific and the Atlantic Oceans and less likely to have originated over Europe and North America. Conversely, in future summers the air mass fractions originating over Asia and North America increase by ~10%, indicating that Arctic pollutant levels may be enhanced owing solely to changes in transport. In particular, our results suggest that more stringent emissions caps may be needed to combat enhanced transport into the Arctic from Asia, where increases in black carbon emissions have already posed concerns. Future changes in air mass fractions are interpreted in terms of large-scale circulation responses that are consistent with CMIP5 multi-model mean projections - namely, upward and poleward shifted meridional transient eddies in future winters and

  13. Seasonal exposure to drought and air warming affects soil Collembola and mites.

    Directory of Open Access Journals (Sweden)

    Guo-Liang Xu

    Full Text Available Global environmental changes affect not only the aboveground but also the belowground components of ecosystems. The effects of seasonal drought and air warming on the genus level richness of Collembola, and on the abundance and biomass of the community of Collembola and mites were studied in an acidic and a calcareous forest soil in a model oak-ecosystem experiment (the Querco experiment at the Swiss Federal Research Institute WSL in Birmensdorf. The experiment included four climate treatments: control, drought with a 60% reduction in rainfall, air warming with a seasonal temperature increase of 1.4 °C, and air warming + drought. Soil water content was greatly reduced by drought. Soil surface temperature was slightly increased by both the air warming and the drought treatment. Soil mesofauna samples were taken at the end of the first experimental year. Drought was found to increase the abundance of the microarthropod fauna, but reduce the biomass of the community. The percentage of small mites (body length ≤ 0.20 mm increased, but the percentage of large mites (body length >0.40 mm decreased under drought. Air warming had only minor effects on the fauna. All climate treatments significantly reduced the richness of Collembola and the biomass of Collembola and mites in acidic soil, but not in calcareous soil. Drought appeared to have a negative impact on soil microarthropod fauna, but the effects of climate change on soil fauna may vary with the soil type.

  14. Operative air temperature data for different measures applied on a building envelope in warm climate

    Directory of Open Access Journals (Sweden)

    Cristina Baglivo

    2018-04-01

    Full Text Available Several technical combinations have been evaluated in order to design high energy performance buildings for the warm climate. The analysis has been developed in several steps, avoiding the use of HVAC systems.The methodological approach of this study is based on a sequential search technique and it is shown on the paper entitled “Envelope Design Optimization by Thermal Modeling of a Building in a Warm Climate” [1].The Operative Air Temperature trends (TOP, for each combination, have been plotted through a dynamic simulation performed using the software TRNSYS 17 (a transient system simulation program, University of Wisconsin, Solar Energy Laboratory, USA, 2010.Starting from the simplest building configuration consisting of 9 rooms (equal-sized modules of 5 × 5 m2, the different building components are sequentially evaluated until the envelope design is optimized. The aim of this study is to perform a step-by-step simulation, simplifying as much as possible the model without making additional variables that can modify their performances. Walls, slab-on-ground floor, roof, shading and windows are among the simulated building components. The results are shown for each combination and evaluated for Brindisi, a city in southern Italy having 1083 degrees day, belonging to the national climatic zone C. The data show the trends of the TOP for each measure applied in the case study for a total of 17 combinations divided into eight steps.

  15. Culture systems: air quality.

    Science.gov (United States)

    Thomas, Theodore

    2012-01-01

    Poor laboratory air quality is a known hazard to the culture of human gametes and embryos. Embryologists and chemists have employed analytical methods for identifying and measuring bulk and select air pollutants to assess the risk they pose to the embryo culture system. However, contaminant concentrations that result in gamete or embryotoxicity are poorly defined. Combating the ill effects of poor air quality requires an understanding of how toxicants can infiltrate the laboratory, the incubator, and ultimately the culture media. A further understanding of site-specific air quality can then lead to the consideration of laboratory design and management strategies that can minimize the deleterious effects that air contamination may have on early embryonic development in vitro.

  16. How motor vehicles contribute to global warming and air pollution

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    In this chapter, the authors describe ways in which motor vehicles are contributing to global climate change and health problems caused by air pollution. Globally, motor vehicles account for about a third of world oil consumption and about 14% of the world's carbon dioxide emissions from fossil fuel burning. For the US the figures are 50% of oil demand and about 25% of carbon dioxide emissions. Motor vehicles are the major source of ozone precursors and monitoring data suggest that ozone concentrations are increasing by about one percent per year in the northern hemisphere and are causing adverse effects on human health and on crops. A major source of chlorofluorocarbons in the atmosphere is motor vehicle air conditioning. Annually about 120,000 metric tons of CFCs are used in new vehicles and in serving air conditioners in older vehicles. According to the EPA, vehicle air conditioners accounted for about 16% of the total CFC use in the US during 1989. According to the Montreal Protocol, CFCs are to be completely phased out of new vehicles by the turn of the century, thus reducing the depletion of the stratospheric ozone layer

  17. Recent Global Warming As Depicted by AIRS, GISSTEMP, and MERRA-2

    Science.gov (United States)

    Susskind, J.; Iredell, L. F.; Lee, J. N.

    2017-12-01

    We observed anomalously warm global mean surface temperatures since 2015. The year 2016 represents the warmest annual mean surface skin and surface air temperatures in the AIRS observational period, September 2002 through August 2017. Additionally, AIRS monthly mean surface skin temperature, from January 2016 through September 2016, and November 2016, were the warmest observed for each month of the year. Continuing this trend, the AIRS global surface temperatures of 2017 February and April show the second greatest positive anomalies from average. This recent warming is particularly significant over the Arctic where the snow and sea ice melt is closely tied to the spring and summer surface temperatures. In this paper, we show the global distribution of surface temperature anomalies as observed by AIRS over the period September 2002 through August 2017 and compare them with those from the GISSTEMP and MERRA-2 surface temperatures. The spatial patterns of warm and cold anomalies for a given month show reasonably good agreement in all three data set. AIRS anomalies, which do not have the benefit of in-situ measurements, are in almost perfect agreement with those of MERRA-2, which does use in-situ surface measurements. GISSTEMP anomaly patterns for the most part look similar to those of AIRS and MERRA-2, but are more spread out spatially, and consequently are also weaker.

  18. Regional air pollution brightening reverses the greenhouse gases induced warming-elevation relationship

    Science.gov (United States)

    Zeng, Zhenzhong; Chen, Anping; Ciais, Philippe; Li, Yue; Li, Laurent Z. X.; Vautard, Robert; Zhou, Liming; Yang, Hui; Huang, Mengtian; Piao, Shilong

    2015-06-01

    Mountain waters, glaciers, hazards, and biodiversity are vulnerable to the impacts of global warming. Warming is projected to amplify over mountains by global climate models, yet meteorological records do not show a uniform acceleration of warming with elevation. Here we explore warming-elevation relationships using records from 2660 meteorological stations and determine that the vertical gradient of warming rate varies with location. The warming is faster at higher altitudes in Asia and western North America, but the opposite is observed over Central Europe and eastern North America which have received more short-wave radiation (brightening) associated with a decrease of aerosols and clouds since the 1980s. We found that altitudinal differences in air pollution (brightening), with observations showing more short-wave radiation received at low altitudes than at mountains, modulate the warming-elevation relationships. The advance in understanding of the drivers of regional climate change will contribute to the formulation of strategies for climate change mitigation at high elevations.

  19. Low clouds suppress Arctic air formation and amplify high-latitude continental winter warming.

    Science.gov (United States)

    Cronin, Timothy W; Tziperman, Eli

    2015-09-15

    High-latitude continents have warmed much more rapidly in recent decades than the rest of the globe, especially in winter, and the maintenance of warm, frost-free conditions in continental interiors in winter has been a long-standing problem of past equable climates. We use an idealized single-column atmospheric model across a range of conditions to study the polar night process of air mass transformation from high-latitude maritime air, with a prescribed initial temperature profile, to much colder high-latitude continental air. We find that a low-cloud feedback--consisting of a robust increase in the duration of optically thick liquid clouds with warming of the initial state--slows radiative cooling of the surface and amplifies continental warming. This low-cloud feedback increases the continental surface air temperature by roughly two degrees for each degree increase of the initial maritime surface air temperature, effectively suppressing Arctic air formation. The time it takes for the surface air temperature to drop below freezing increases nonlinearly to ∼ 10 d for initial maritime surface air temperatures of 20 °C. These results, supplemented by an analysis of Coupled Model Intercomparison Project phase 5 climate model runs that shows large increases in cloud water path and surface cloud longwave forcing in warmer climates, suggest that the "lapse rate feedback" in simulations of anthropogenic climate change may be related to the influence of low clouds on the stratification of the lower troposphere. The results also indicate that optically thick stratus cloud decks could help to maintain frost-free winter continental interiors in equable climates.

  20. Nitrogen dynamics in oak model ecosystems subjected to air warming and drought on two different soils.

    Science.gov (United States)

    Kuster, T M; Schleppi, P; Hu, B; Schulin, R; Günthardt-Goerg, M S

    2013-01-01

    Being tolerant to heat and drought, oaks are promising candidates for future forestry in view of climate change in Central Europe. Air warming is expected to increase, and drought decrease soil N availability and thus N supply to trees. Here, we conducted a model ecosystem experiment, in which mixed stands of young oaks (Quercus robur, Q. petraea and Q. pubescens) were grown on two different soils and subjected to four climate treatments during three growing seasons: air warming by 1-2 °C, drought periods (average precipitation reduction of 43-60%), a combination of these two treatments, and a control. In contrast to our hypotheses, neither air warming nor drought significantly affected N availability, whereas total amounts, vertical distribution and availability of soil N showed substantial differences between the two soils. While air warming had no effect on tree growth and N accumulation, the drought treatment reduced tree growth and increased, or tended to increase, N accumulation in the reduced biomass, indicating that growth was not limited by N. Furthermore, (15) N-labelling revealed that this accumulation was associated with an increased uptake of nitrate. On the basis of our results, climate change effects on N dynamics are expected to be less important in oak stands than reduced soil water availability. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. Air conditioning cool contribution to global warming?; Airconditioning koele bijdrage aan global warming?

    Energy Technology Data Exchange (ETDEWEB)

    Oudshoff, B.

    2010-06-15

    Similar to the Netherlands, the percentage of buildings with air-conditioning is growing steadily in the United Stated (US). This makes it an interesting area for energy saving. New technological developments offer opportunities to drastically reduce energy use for cooling. The best option is obviously to no longer deploy mechanical cooling but this is not a realistic option for warmer areas. This article addresses new technologies and several newly established companies in California and Colorado that target this market. [Dutch] In de Verenigde Staten (VS) groeit het percentage van gebouwen met airconditioning, net als in Nederland, de laatste jaren gestaag door. Hiermee is het een interessant gebied voor mogelijke energiebesparing. Nieuwe technologische ontwikkelingen bieden kansen om het energiegebruik voor koeling drastisch te verminderen. De beste oplossing is uiteraard geen mechanische koeling meer toe te passen maar voor warmere gebieden is die optie niet reeel. In dit artikel wordt ingegaan op nieuwe technologie en enkele startende bedrijven in Californie en Colorado die zich op deze markt richten.

  2. Recent Global Warming as Observed by AIRS and Depicted in GISSTEMP and MERRA-2

    Science.gov (United States)

    Susskind, Joel; Lee, Jae; Iredell, Lena

    2017-01-01

    AIRS Version-6 monthly mean level-3 surface temperature products confirm the result, depicted in the GISSTEMP dataset, that the earth's surface temperature has been warming since early 2015, though not before that. AIRS is at a higher spatial resolution than GISSTEMP, and produces sharper spatial features which are otherwise in excellent agreement with those of GISSTEMP. Version-6 AO Ts anomalies are consistent with those of Version-6 AIRS/AMSU. Version-7 AO anomalies should be even more accurate, especially at high latitudes. ARCs of MERRA-2 Ts anomalies are spurious as a result of a discontinuity which occurred somewhere between 2007 and 2008. This decreases global mean trends.

  3. Exceptional Air Mass Transport and Dynamical Drivers of an Extreme Wintertime Arctic Warm Event

    Science.gov (United States)

    Binder, Hanin; Boettcher, Maxi; Grams, Christian M.; Joos, Hanna; Pfahl, Stephan; Wernli, Heini

    2017-12-01

    At the turn of the years 2015/2016, maximum surface temperature in the Arctic reached record-high values, exceeding the melting point, which led to a strong reduction of the Arctic sea ice extent in the middle of the cold season. Here we show, using a Lagrangian method, that a combination of very different airstreams contributed to this event: (i) warm low-level air of subtropical origin, (ii) initially cold low-level air of polar origin heated by surface fluxes, and (iii) strongly descending air heated by adiabatic compression. The poleward transport of these warm airstreams occurred along an intense low-level jet between a series of cyclones and a quasi-stationary anticyclone. The complex 3-D configuration that enabled this transport was facilitated by continuous warm conveyor belt ascent into the upper part of the anticyclone. This study emphasizes the combined role of multiple transport processes and transient synoptic-scale dynamics for establishing an extreme Arctic warm event.

  4. The effect of warm air-blowing on the microtensile bond strength of one-step self-etch adhesives to root canal dentin.

    Science.gov (United States)

    Taguchi, Keita; Hosaka, Keiichi; Ikeda, Masaomi; Kishikawa, Ryuzo; Foxton, Richard; Nakajima, Masatoshi; Tagami, Junji

    2018-01-31

    The use of warm air-blowing to evaporate solvents of one-step self-etch adhesive systems (1-SEAs) has been reported to be a useful method. The purpose of this study was to evaluate the effect of warm air-blowing on root canal dentin. Four 1-SEAs (Clearfil Bond SE ONE, Unifil Core EM self-etch bond, Estelink, BeautiDualbond EX) were used. Each 1-SEA was applied to root canal dentin according to the manufacturers' instructions. After the adhesives were applied, solvent was evaporated using either normal air (23±1°C) or warm air (80±1°C) for 20s, and resin composite was placed in the post spaces. The air from the dryer, which could be used in normal- or hot-air-mode, was applied at a distance of 5cm above the root canal cavity in the direction of tooth axis. The temperature of the stream of air from the dryer in the hot-air-mode was 80±1°C, and in the normal mode, 23±1°C. After water storage of the specimens for 24h, the μTBS were evaluated at the coronal and apical regions. The μTBSs were statistically analyzed using three-way ANOVA and Student's t-test with Bonferroni correction (α=0.05). The warm air-blowing significantly increased the μTBS of all 1-SEAs at the apical regions, and also significantly increased the μTBS of two adhesives (Estelink and BeautiDualBond EX) at coronal regions. The μTBS of 1-SEAs to root canal dentin was improved by using warm air-blowing. Copyright © 2017 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  5. Air System Information Management

    Science.gov (United States)

    Filman, Robert E.

    2004-01-01

    I flew to Washington last week, a trip rich in distributed information management. Buying tickets, at the gate, in flight, landing and at the baggage claim, myriad messages about my reservation, the weather, our flight plans, gates, bags and so forth flew among a variety of travel agency, airline and Federal Aviation Administration (FAA) computers and personnel. By and large, each kind of information ran on a particular application, often specialized to own data formats and communications network. I went to Washington to attend an FAA meeting on System-Wide Information Management (SWIM) for the National Airspace System (NAS) (http://www.nasarchitecture.faa.gov/Tutorials/NAS101.cfm). NAS (and its information infrastructure, SWIM) is an attempt to bring greater regularity, efficiency and uniformity to the collection of stovepipe applications now used to manage air traffic. Current systems hold information about flight plans, flight trajectories, weather, air turbulence, current and forecast weather, radar summaries, hazardous condition warnings, airport and airspace capacity constraints, temporary flight restrictions, and so forth. Information moving among these stovepipe systems is usually mediated by people (for example, air traffic controllers) or single-purpose applications. People, whose intelligence is critical for difficult tasks and unusual circumstances, are not as efficient as computers for tasks that can be automated. Better information sharing can lead to higher system capacity, more efficient utilization and safer operations. Better information sharing through greater automation is possible though not necessarily easy.

  6. Cropping system innovation for coping with climatic warming in China

    Directory of Open Access Journals (Sweden)

    Aixing Deng

    2017-04-01

    Full Text Available China is becoming the largest grain producing and carbon-emitting country in the world, with a steady increase in population and economic development. A review of Chinese experiences in ensuring food self-sufficiency and reducing carbon emission in the agricultural sector can provide a valuable reference for similar countries and regions. According to a comprehensive review of previous publications and recent field observations, China has experienced on average a larger and faster climatic warming trend than the global trend, and there are large uncertainties in precipitation change, which shows a non-significantly increasing trend. Existing evidence shows that the effects of climatic warming on major staple crop production in China could be markedly negative or positive, depending on the specific cropping region, season, and crop. However, historical data analysis and field warming experiments have shown that moderate warming, of less than 2.0 °C, could benefit crop production in China overall. During the most recent warming decades, China has made successful adaptations in cropping systems, such as new cultivar breeding, cropping region adjustment, and cropping practice optimization, to exploit the positive rather than to avoid the negative effects of climatic warming on crop growth. All of these successful adaptations have greatly increased crop yield, leading to higher resource use efficiency as well as greatly increased soil organic carbon content with reduced greenhouse gas emissions. Under the warming climate, China has not only achieved great successes in crop production but also realized a large advance in greenhouse gas emission mitigation. Chinese experiences in cropping system innovation for coping with climatic warming demonstrate that food security and climatic warming mitigation can be synergized through policy, knowledge, and technological innovation. With the increasingly critical status of food security and climatic warming

  7. A phenological timetable of oak growth under experimental drought and air warming.

    Directory of Open Access Journals (Sweden)

    Thomas M Kuster

    Full Text Available Climate change is expected to increase temperature and decrease summer precipitation in Central Europe. Little is known about how warming and drought will affect phenological patterns of oaks, which are considered to possess excellent adaptability to these climatic changes. Here, we investigated bud burst and intra-annual shoot growth of Quercus robur, Q. petraea and Q. pubescens grown on two different forest soils and exposed to air warming and drought. Phenological development was assessed over the course of three growing seasons. Warming advanced bud burst by 1-3 days °C⁻¹ and led to an earlier start of intra-annual shoot growth. Despite this phenological shift, total time span of annual growth and shoot biomass were not affected. Drought changed the frequency and intensity of intra-annual shoot growth and advanced bud burst in the subsequent spring of a severe summer drought by 1-2 days. After re-wetting, shoot growth recovered within a few days, demonstrating the superior drought tolerance of this tree genus. Our findings show that phenological patterns of oaks are modified by warming and drought but also suggest that ontogenetic factors and/or limitations of water and nutrients counteract warming effects on the biomass and the entire span of annual shoot growth.

  8. Performance Optimization of Alternative Lower Global Warming Potential Refrigerants in Mini-Split Room Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Bo [ORNL; Abdelaziz, Omar [ORNL; Shrestha, Som S [ORNL

    2017-01-01

    Oak Ridge National laboratory (ORNL) recently conducted extensive laboratory, drop-in investigations for lower Global Warming Potential (GWP) refrigerants to replace R-22 and R-410A. ORNL studied propane, DR-3, ARM-20B, N-20B and R-444B as lower GWP refrigerant replacement for R-22 in a mini-split room air conditioner (RAC) originally designed for R-22; and, R-32, DR-55, ARM-71A, and L41-2, in a mini-split RAC designed for R-410A. We obtained laboratory testing results with very good energy balance and nominal measurement uncertainty. Drop-in studies are not enough to judge the overall performance of the alternative refrigerants since their thermodynamic and transport properties might favor different heat exchanger configurations, e.g. cross-flow, counter flow, etc. This study compares optimized performances of individual refrigerants using a physics-based system model tools. The DOE/ORNL Heat Pump Design Model (HPDM) was used to model the mini-split RACs by inputting detailed heat exchangers geometries, compressor displacement and efficiencies as well as other relevant system components. The RAC models were calibrated against the lab data for each individual refrigerant. The calibrated models were then used to conduct a design optimization for the cooling performance by varying the compressor displacement to match the required capacity, and changing the number of circuits, refrigerant flow direction, tube diameters, air flow rates in the condenser and evaporator at 100% and 50% cooling capacities. This paper compares the optimized performance results for all alternative refrigerants and highlights best candidates for R-22 and R-410A replacement.

  9. Optimal design of a general warm standby system

    International Nuclear Information System (INIS)

    Yun, Won Young; Cha, Ji Hwan

    2010-01-01

    Redundancy or standby is a technique that has been widely applied to improving system reliability and availability in the stage of system design. In this paper, we consider a standby system with two units in which the first unit (unit 1) starts its operation under active state and the other unit (unit 2) is under cold standby state at the starting point. After a specified time s (switching time), the state of unit 2 is changed to warm standby state and, as soon as the operating unit 1 fails, the state of unit 2 is changed to active state. If unit 1 fails before time s, the system fails. Units can fail at both active and warm standby states. A general method for modeling the standby system is adopted and system performance measures (system reliability and mean life) based on the proposed model are derived. Three models - a perfect switching model and two imperfect switching models - are considered in this paper. Two imperfect switching models include an imperfect switching probability and a preliminary warm-up period which is required for the change from cold standby state to warm standby state. We consider the problem of determining the optimal switching time which maximizes the expected system life and related allocation problem is also discussed. Some numerical examples are studied.

  10. Low Global Warming Potential Refrigerants for Commercial Refrigeration Systems

    Energy Technology Data Exchange (ETDEWEB)

    Fricke, Brian A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Sharma, Vishaldeep [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    Supermarket refrigeration systems account for approximately 50% of supermarket energy use, placing this class of equipment among the highest energy consumers in the commercial building domain. In addition, the commonly used refrigeration system in supermarket applications is the multiplex direct expansion (DX) system, which is prone to refrigerant leaks due to its long lengths of refrigerant piping. This leakage reduces the efficiency of the system and increases the impact of the system on the environment. The high Global Warming Potential (GWP) of the hydrofluorocarbon (HFC) refrigerants commonly used in these systems, coupled with the large refrigerant charge and the high refrigerant leakage rates leads to significant direct emissions of greenhouse gases into the atmosphere. Environmental concerns are driving regulations for the heating, ventilating, air-conditioning and refrigeration (HVAC&R) industry towards lower GWP alternatives to HFC refrigerants. Existing lower GWP refrigerant alternatives include hydrocarbons, such as propane (R-290) and isobutane (R-600a), as well as carbon dioxide (R-744), ammonia (R-717), and R-32. In addition, new lower GWP refrigerant alternatives are currently being developed by refrigerant manufacturers, including hydrofluoro-olefin (HFO) and unsaturated hydrochlorofluorocarbon (HCFO) refrigerants. The selection of an appropriate refrigerant for a given refrigeration application should be based on several factors, including the GWP of the refrigerant, the energy consumption of the refrigeration system over its operating lifetime, and leakage of refrigerant over the system lifetime. For example, focusing on energy efficiency alone may overlook the significant environmental impact of refrigerant leakage; while focusing on GWP alone might result in lower efficiency systems that result in higher indirect impact over the equipment lifetime. Thus, the objective of this Collaborative Research and Development Agreement (CRADA) between

  11. Intra-operative warming with a forced-air warmer in preventing hypothermia after tourniquet deflation in elderly patients.

    Science.gov (United States)

    Kim, Y-S; Jeon, Y-S; Lee, J-A; Park, W-K; Koh, H-S; Joo, J-D; In, J-H; Seo, K-W

    2009-01-01

    This randomized, single-blind study aimed to explore the effects of intra-operative warming with a forced-air warmer in the prevention of hypothermia after tourniquet deflation in elderly patients undergoing unilateral total knee replacement arthroplasty under general anaesthesia. Patients were randomized to receive either intra-operative warming using a forced-air warmer with an upper body blanket (warming group; n = 12) or no intra-operative warming (nonwarming group; n = 12). Oesophageal temperature was measured as core body temperature. At 30 min following tourniquet inflation, the core body temperature started to increase in the warming group whereas it continued to drop in the non-warming group. This difference was statistically significant. The final core body temperature after tourniquet deflation was significantly higher in the warming group (mean +/- SD 36.1 +/- 0.2 degrees C) than in the non-warming group (35.4 +/- 0.3 degrees C). Intra-operative forced-air warming increased the core body temperature before tourniquet deflation and prevented subsequent hypothermia in elderly patients under general anaesthesia.

  12. 10 CFR 431.76 - Uniform test method for the measurement of energy efficiency of commercial warm air furnaces.

    Science.gov (United States)

    2010-01-01

    ..., Downflow or Horizontal Furnace Test), of the UL Standard 727-1994. You must conduct a fuel oil analysis for... EPCA, you are measuring the steady state thermal efficiency of a gas-fired or oil-fired commercial warm...) Test setup for gas-fired commercial warm air furnaces. The test setup, including flue requirement...

  13. The effect of global warming on BTES systems

    OpenAIRE

    Kharseh, Mohamad; Altorkmany, Lobna; Nordell, Bo

    2009-01-01

    Global warming (GW) is linked to the use of conventional energy, mainly fossil fuels. There is a general understanding that the way to reduce GW is more efficient use of energy and increased use of renewable energy. Heating and cooling of buildings account for more than one third of the world's primary energy consumption. Using the ground as a heat/cold source means more sustainable heating and cooling. The ongoing GW means that heat is accumulating in air, ground and water. Since BTESs are u...

  14. Solid State Air Purification System

    Data.gov (United States)

    National Aeronautics and Space Administration — The solid state air purification project will explore feasibility of a new air purification system based on a liquid membrane, capable of purifying carbon dioxide...

  15. Regional Contrasts of the Warming Rate over Land Significantly Depend on the Calculation Methods of Mean Air Temperature

    Science.gov (United States)

    Wang, Kaicun; Zhou, Chunlüe

    2015-01-01

    Global analyses of surface mean air temperature (Tm) are key datasets for climate change studies and provide fundamental evidences for global warming. However, the causes of regional contrasts in the warming rate revealed by such datasets, i.e., enhanced warming rates over the northern high latitudes and the “warming hole” over the central U.S., are still under debate. Here we show these regional contrasts depend on the calculation methods of Tm. Existing global analyses calculate Tm from daily minimum and maximum temperatures (T2). We found that T2 has a significant standard deviation error of 0.23 °C/decade in depicting the regional warming rate from 2000 to 2013 but can be reduced by two-thirds using Tm calculated from observations at four specific times (T4), which samples diurnal cycle of land surface air temperature more often. From 1973 to 1997, compared with T4, T2 significantly underestimated the warming rate over the central U.S. and overestimated the warming rate over the northern high latitudes. The ratio of the warming rate over China to that over the U.S. reduces from 2.3 by T2 to 1.4 by T4. This study shows that the studies of regional warming can be substantially improved by T4 instead of T2. PMID:26198976

  16. Contribution of air conditioning adoption to future energy use under global warming

    Science.gov (United States)

    Davis, Lucas W.; Gertler, Paul J.

    2015-01-01

    As household incomes rise around the world and global temperatures go up, the use of air conditioning is poised to increase dramatically. Air conditioning growth is expected to be particularly strong in middle-income countries, but direct empirical evidence is scarce. In this paper we use high-quality microdata from Mexico to describe the relationship between temperature, income, and air conditioning. We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air conditioning adoption decisions. We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Under conservative assumptions about household income, our model predicts near-universal saturation of air conditioning in all warm areas within just a few decades. Temperature increases contribute to this surge in adoption, but income growth by itself explains most of the increase. What this will mean for electricity consumption and carbon dioxide emissions depends on the pace of technological change. Continued advances in energy efficiency or the development of new cooling technologies could reduce the energy consumption impacts. Similarly, growth in low-carbon electricity generation could mitigate the increases in carbon dioxide emissions. However, the paper illustrates the enormous potential impacts in this sector, highlighting the importance of future research on adaptation and underscoring the urgent need for global action on climate change. PMID:25918391

  17. Contribution of air conditioning adoption to future energy use under global warming.

    Science.gov (United States)

    Davis, Lucas W; Gertler, Paul J

    2015-05-12

    As household incomes rise around the world and global temperatures go up, the use of air conditioning is poised to increase dramatically. Air conditioning growth is expected to be particularly strong in middle-income countries, but direct empirical evidence is scarce. In this paper we use high-quality microdata from Mexico to describe the relationship between temperature, income, and air conditioning. We describe both how electricity consumption increases with temperature given current levels of air conditioning, and how climate and income drive air conditioning adoption decisions. We then combine these estimates with predicted end-of-century temperature changes to forecast future energy consumption. Under conservative assumptions about household income, our model predicts near-universal saturation of air conditioning in all warm areas within just a few decades. Temperature increases contribute to this surge in adoption, but income growth by itself explains most of the increase. What this will mean for electricity consumption and carbon dioxide emissions depends on the pace of technological change. Continued advances in energy efficiency or the development of new cooling technologies could reduce the energy consumption impacts. Similarly, growth in low-carbon electricity generation could mitigate the increases in carbon dioxide emissions. However, the paper illustrates the enormous potential impacts in this sector, highlighting the importance of future research on adaptation and underscoring the urgent need for global action on climate change.

  18. Manual for THOR-AirPAS - air pollution assessment system

    DEFF Research Database (Denmark)

    Jensen, Steen Solvang; Ketzel, Matthias; Brandt, Jørgen

    The report provides an outline of the THOR-AirPAS - air pollution assessment system and a brief manual for getting started with the air quality models and input data included in THOR-AirPAS.......The report provides an outline of the THOR-AirPAS - air pollution assessment system and a brief manual for getting started with the air quality models and input data included in THOR-AirPAS....

  19. Evaluation of comfort level in desks equipped with two personalized ventilation systems in slightly warm environments

    Energy Technology Data Exchange (ETDEWEB)

    Conceicao, Eusebio Z.E. [Faculdade de Ciencias e Tecnologia - Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal); Lucio, Manuela J.R. [Agrupamento Vertical Professor Paula Nogueira, R. Comunidade Lusiada, 8700-000 Olhao (Portugal); Rosa, Silvia P.; Custodio, Ana L.V.; Andrade, Renata L.; Meira, Maria J.P.A. [Faculdade de Ciencias do Mar e do Ambiente - Universidade do Algarve, Campus de Gambelas, 8005-139 Faro (Portugal)

    2010-03-15

    In this work the comfort level, namely the thermal comfort, local thermal discomfort and air quality levels, in a classroom with desks equipped with two personalized ventilation systems, in slightly warm environments, is evaluated. A manikin, a ventilated classroom desk, two indoor climate analyzers, a multi-nodal human thermal comfort numerical model and a computational fluid dynamic numerical model, are used. The classroom desk, with double occupation capacity, is used by a student, located in the right side seat. Each personalized ventilation system is equipped with one air terminal device located above the desk writing area, in front to the trunk area, and an other located below the desk writing area, in front to the legs area. The thermal comfort level is evaluated by the developed multi-nodal human thermal comfort numerical model, using a PMV value, the local thermal discomfort level, namely the draught risk and the air velocity fluctuation equivalent frequencies, is evaluated by empirical models, while the air quality level and the detailed airflow around the manikin are evaluated by the computational fluid dynamic numerical model. In the experimental tests the mean air velocity and the turbulence intensity in the upper air terminal device are 3.5 m/s and 9.7%, while in the lower air terminal device are 2.6 m/s and 15.2%. The mean air temperature in the air terminal devices is around 28 C, while the mean radiant temperature in the occupation area, the mean air temperature far from the occupation area and the internal mean air relative humidity were, respectively, 28 C, 28 C and 50%. The air velocity and temperature around the occupant are measured around 15 human body sections. The actual personalized ventilation system, which promotes an ascendant airflow around the occupant with highest air renovation rate in the respiration area, promotes acceptable thermal comfort conditions and air quality in the respiration area in accord to the present standards. The

  20. Implications of climate change (global warming) for the healthcare system.

    Science.gov (United States)

    Raffa, R B; Eltoukhy, N S; Raffa, K F

    2012-10-01

    Temperature-sensitive pathogenic species and their vectors and hosts are emerging in previously colder regions as a consequence of several factors, including global warming. As a result, an increasing number of people will be exposed to pathogens against which they have not previously needed defences. We illustrate this with a specific example of recent emergence of Cryptococcus gattii infections in more temperate climates. The outbreaks in more temperate climates of the highly virulent--but usually tropically restricted--C. gattii is illustrative of an anticipated growing challenge for the healthcare system. There is a need for preparedness by healthcare professionals in anticipation and for management of such outbreaks, including other infections whose recent increased prevalence in temperate climates can be at least partly associated with global warming. (Re)emergence of temperature-sensitive pathogenic species in more temperate climates will present new challenges for healthcare systems. Preparation for outbreaks should precede their occurrence. © 2012 Blackwell Publishing Ltd.

  1. Xylem anatomical responses of Vaccinium myrtillus exposed to air CO2 enrichment and soil warming at treeline

    Science.gov (United States)

    Anadon-Rosell, Alba; Fonti, Patrick; Dawes, Melissa; von Arx, Georg

    2016-04-01

    Plant life at treeline is limited by harsh growth conditions. In this study we used nine years of free air CO2 enrichment (+200 ppm from 2001 to 2009) and six years of soil warming (+4 °C from 2007 to 2012) at a treeline experimental site in the Swiss Alps to investigate xylem anatomical responses of Vaccinium myrtillus, a co-dominant dwarf shrub in many treeline communities. Our aim was to identify whether the release from limiting growth conditions induced adjustments of the water conductive and storage tissues. High-resolution images of wood anatomical microsections from the stem base of 40 individuals were captured with a digital camera mounted on a microscope. We used the specialized image analysis tool ROXAS to quantify size, density, grouping patterns, and potential hydraulic conductivity of vessels. In addition, we measured the abundance and distribution of ray parenchyma. Our preliminary results show that CO2 enrichment and soil warming induced contrasting anatomical responses. In the last years of the CO2 enhancement vessels were larger, whereas soil warming induced an immediate reduction of vessel size. Moreover, larger vessels were found when V. myrtillus was in cohabitation with pine as opposed to larch. Results for ray parenchyma measurements did not show clear trends, although warming seemed to have a slightly positive effect on the fraction of uniseriate vs. multiseriate rays. These results suggest that release from the growth limiting factors can result in contrasting and partially lagged responses in the hydraulic system with little impact on the storage tissues. In addition, the overstory species seem to play a key role on the anatomy of V. myrtillus at treeline.

  2. Impact of energy consumption on urban warming and air pollution in Tokyo metropolitan area

    International Nuclear Information System (INIS)

    Saitoh, T.S.; Hoshi, H.

    1995-01-01

    The rapid progress of industrialization and urbanization due to economic growth and concentration of social function in the urban areas in Japan have had an adverse effect on the urban environment. In most cities, it has become evident that the increase in energy consumption is causing environmental problems, including a temperature rise in the urban atmosphere (urban heat island) and air pollution. This paper reports the results of field observations and three dimensional simulations of the urban heat island using a three-dimensional modelling vorticity-velocity vector potential formation, in the Tokyo metropolitan area. According to the simulation for urban warming in the study area for the year 2031, the maximum temperature of a summer evening (18:00) would exceed 43 degrees celsius, indicating that Tokyo would no longer be comfortable for its inhabitants. It is concluded that in the near future, the problem of the urban heat island will become a more important issue than that of global warming because the rate of urban warming is greater. For this reason, the urban heat island could be fatal to humans unless resolved in the near future. (author). 1 tab., 11 figs., 18 refs

  3. Low Global Warming Refrigerants For Commercial Refrigeration Systems

    OpenAIRE

    Yana Motta, Samuel F.; Becerra, Elizabet Vera; Spatz, Mark W

    2012-01-01

    New refrigerants with the positive attributes of both high thermal performance and low environmental impact are currently in development. Initial evaluation of these refrigerants in refrigeration systems show good energy efficiency and significant lower global warming impact than current refrigerants. Some of those Low GWP refrigerants are non-azeotropic blends with moderate to high glide; therefore guidance on the use of these blends is needed to achieve the desired good performance and low ...

  4. REAL TIME WIRELESS AIR POLLUTION MONITORING SYSTEM

    Directory of Open Access Journals (Sweden)

    Raja Vara Prasad Y

    2011-06-01

    Full Text Available Air pollution has significant influence on the concentration of constituents in the atmosphere leading to effects like global warming and acid rains. To avoid such adverse imbalances in the nature, an air pollution monitoring system is utmost important. This paper attempts to develop an effective solution for pollution monitoring using wireless sensor networks (WSN on a real time basis namely real time wireless air pollution monitoring system. Commercially available discrete gas sensors for sensing concentration of gases like CO2, NO2, CO and O2 are calibrated using appropriate calibration technologies. These pre-calibrated gas sensors are then integrated with the wireless sensor motes for field deployment at the campus and the Hyderabad city using multi hop data aggregation algorithm. A light weight middleware and a web interface to view the live pollution data in the form of numbers and charts from the test beds was developed and made available from anywhere on the internet. Other parameters like temperature and humidity were also sensed along with gas concentrations to enable data analysis through data fusion techniques. Experimentation carried out using the developed wireless air pollution monitoring system under different physical conditions show that the system collects reliable source of real time fine-grain pollution data.

  5. Air barrier systems: Construction applications

    Energy Technology Data Exchange (ETDEWEB)

    Perrault, J.C

    1989-01-01

    An examination is presented of how ordinary building materials can be used in an innovative manner to design, detail, and construct effective air barrier systems for common types of walls. For residential construction, the air drywall approach uses the interior gypsum board as the main component of the wall air barrier system. Joints between the gypsum board and adjacent materials or assemblies are sealed by gaskets. In commercial construction, two different techniques are employed for using gypsum board as air barrier material: the accessible drywall and non-accessible drywall approaches. The former is similar to the air drywall approach except that high performance sealants are used instead of gaskets. In the latter approach, exterior drywall sheathing is the main component of the air barrier system; joints between boards are taped and joints between boards and other components are sealed using elastomeric membrane strips. For various types of commercial and institutional buildings, metal air barrier systems are widely used and include pre-engineered curtain walls or sheet metal walls. Masonry wall systems are regarded as still the most durable, fireproof, and soundproof wall type available but an effective air barrier system has typically been difficult to implement. Factory-made elastomeric membranes offer the potential to provide airtightness to masonry walls. These membranes are applied on the entire masonry wall surface and are used to make airtight connections with other building components. Two types of product are available: thermofusible and peel-and-stick membranes. 5 figs.

  6. The Earth System's Missing Energy and Land Warming

    Science.gov (United States)

    Huang, S.; Wang, H.; Duan, W.

    2013-05-01

    The energy content of the Earth system is determined by the balance or imbalance between the incoming energy from solar radiation and the outgoing energy of terrestrial long wavelength radiation. Change in the Earth system energy budget is the ultimate cause of global climate change. Satellite data show that there is a small yet persistent radiation imbalance at the top-of-atmosphere such that Earth has been steadily accumulating energy, consistent with the theory of greenhouse effect. It is commonly believed [IPCC, 2001; 2007] that up to 94% of the energy trapped by anthropogenic greenhouse gases is absorbed by the upper several hundred meter thick layer of global oceans, with the remaining to accomplish ice melting, atmosphere heating, and land warming, etc. However, the recent measurements from ocean monitoring system indicated that the rate of oceanic heat uptake has not kept pace with the greenhouse heat trapping rate over the past years [Trenberth and Fasullo, Science, 328: 316-317, 2010]. An increasing amount of energy added to the earth system has become unaccounted for, or is missing. A recent study [Loeb et al., Nature Geoscience, 5:110-113, 2012] suggests that the missing energy may be located in the deep ocean down to 1,800 m. Here we show that at least part of the missing energy can be alternatively explained by the land mass warming. We argue that the global continents alone should have a share greater than 10% of the global warming energy. Although the global lands reflect solar energy at a higher rate, they use less energy for evaporation than do the oceans. Taken into accounts the terrestrial/oceanic differences in albedo (34% vs. 28%) and latent heat (27% vs. 58% of net solar radiation at the surface), the radiative energy available per unit surface area for storage or other internal processes is more abundant on land than on ocean. Despite that the lands cover only about 29% of the globe, the portion of global warming energy stored in the lands

  7. Airport Information Retrieval System (AIRS) System Design

    Science.gov (United States)

    1974-07-01

    This report presents the system design for a prototype air traffic flow control automation system developed for the FAA's Systems Command Center. The design was directed toward the immediate automation of airport data for use in traffic load predicti...

  8. Environmentally Benign Lubricant Systems For Cold, Warm And Hot Forging

    DEFF Research Database (Denmark)

    Bay, Niels

    2010-01-01

    The growing awareness of environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has initiated ever increasing efforts to develop new, environmentally benign tribological systems for metal forming. The present...... paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging. The paper is an extract of the keynote paper [3] written by the author together with eight co-authors referring to collected papers and other information from more than 30 different...

  9. Air ejector augmented compressed air energy storage system

    Science.gov (United States)

    Ahrens, F.W.; Kartsounes, G.T.

    Energy is stored in slack demand periods by charging a plurality of underground reservoirs with air to the same peak storage pressure, during peak demand periods throttling the air from one storage reservoir into a gas turbine system at a constant inlet pressure until the air presure in the reservoir falls to said constant inlet pressure, thereupon permitting air in a second reservoir to flow into said gas turbine system while drawing air from the first reservoir through a variable geometry air ejector and adjusting said variable geometry air ejector, said air flow being essentially at the constant inlet pressure of the gas turbine system.

  10. Interactions between summer warm-air advection, melting sea ice and low clouds

    Science.gov (United States)

    Tjernstrom, M. K. H.; Achtert, P.; Shupe, M.; Prytherch, J.; Sedlar, J.; Brooks, B. J.; Brooks, I. M.; Persson, O. P. G.; Salisbury, D.; Sotiropoulou, G.

    2017-12-01

    Over the last decade or more, the influence of advection of heat and moisture into the Arctic from the south has been discussed. Very few studies were based on observations and the focus has mainly been on winter and spring conditions. In summer the situation is slightly different; the ice and any snow on top of it is melting, constraining the surface temperature to the melting point of fresh water. As warm and moist air is advected from south in over the ice, this leads to formation of very strong surface inversions with high relative humidity, often leading to fog formation. In a zone from the ice edge and downstream a competition between several factors becomes important: Radiative cooling at the fog top, potentially leading to turbulent overturning; Strong static stability leading to reduced turbulence; Increased wind shear promoting more shear-generated turbulence, and; Maintenance of the fog, by moisture advection, and the stability, by temperature advection. The vertical structure of the PBL and hence the forcing on the ice from turbulence and radiation is determined by the balance of these factors. We will present an analysis of these processes using observations from the Arctic Clouds in Summer Experiment (ACSE), conducted on board the Swedish icebreaker Oden in summer/autumn 2014, traversing across the Arctic from Tromsö, Norway, to Barrow, Alaska, and back. Using an extensive suite of in-situ and ship-borne remote sensing, we explore all the times that the Oden spent in the sea ice, and show how the different atmospheric parameters, and ultimately the surface energy budget, vary with the existence of a surface inversions and show that these almost exclusively occurred in cases with flow from the south and advection of warm and sometimes moist air onto the ice.

  11. Influence of warm air-drying on enamel bond strength and surface free-energy of self-etch adhesives.

    Science.gov (United States)

    Shiratsuchi, Koji; Tsujimoto, Akimasa; Takamizawa, Toshiki; Furuichi, Tetsuya; Tsubota, Keishi; Kurokawa, Hiroyasu; Miyazaki, Masashi

    2013-08-01

    We examined the effect of warm air-drying on the enamel bond strengths and the surface free-energy of three single-step self-etch adhesives. Bovine mandibular incisors were mounted in self-curing resin and then wet ground with #600 silicon carbide (SiC) paper. The adhesives were applied according to the instructions of the respective manufacturers and then dried in a stream of normal (23°C) or warm (37°C) air for 5, 10, and 20 s. After visible-light irradiation of the adhesives, resin composites were condensed into a mold and polymerized. Ten samples per test group were stored in distilled water at 37°C for 24 h and then the bond strengths were measured. The surface free-energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The enamel bond strengths varied according to the air-drying time and ranged from 15.8 to 19.1 MPa. The trends for the bond strengths were different among the materials. The value of the γS⁺ component increased slightly when drying was performed with a stream of warm air, whereas that of the γS⁻ component decreased significantly. These data suggest that warm air-drying is essential to obtain adequate enamel bond strengths, although increasing the drying time did not significantly influence the bond strength. © 2013 Eur J Oral Sci.

  12. Air transport system

    CERN Document Server

    Schmitt, Dieter

    2016-01-01

    The book addresses all major aspects to be considered for the design and operation of aircrafts within the entire transportation chain. It provides the basic information about the legal environment, which defines the basic requirements for aircraft design and aircraft operation. The interactions between  airport, air traffic management and the airlines are described. The market forecast methods and the aircraft development process are explained to understand the very complex and risky business of an aircraft manufacturer. The principles of flight physics as basis for aircraft design are presented and linked to the operational and legal aspects of air transport including all environmental impacts. The book is written for graduate students as well as for engineers and experts, who are working in aerospace industry, at airports or in the domain of transport and logistics.

  13. Modeling Multi-Reservoir Hydropower Systems in the Sierra Nevada with Environmental Requirements and Climate Warming

    Science.gov (United States)

    Rheinheimer, David Emmanuel

    Hydropower systems and other river regulation often harm instream ecosystems, partly by altering the natural flow and temperature regimes that ecosystems have historically depended on. These effects are compounded at regional scales. As hydropower and ecosystems are increasingly valued globally due to growing values for clean energy and native species as well as and new threats from climate warming, it is important to understand how climate warming might affect these systems, to identify tradeoffs between different water uses for different climate conditions, and to identify promising water management solutions. This research uses traditional simulation and optimization to explore these issues in California's upper west slope Sierra Nevada mountains. The Sierra Nevada provides most of the water for California's vast water supply system, supporting high-elevation hydropower generation, ecosystems, recreation, and some local municipal and agricultural water supply along the way. However, regional climate warming is expected to reduce snowmelt and shift runoff to earlier in the year, affecting all water uses. This dissertation begins by reviewing important literature related to the broader motivations of this study, including river regulation, freshwater conservation, and climate change. It then describes three substantial studies. First, a weekly time step water resources management model spanning the Feather River watershed in the north to the Kern River watershed in the south is developed. The model, which uses the Water Evaluation And Planning System (WEAP), includes reservoirs, run-of-river hydropower, variable head hydropower, water supply demand, and instream flow requirements. The model is applied with a runoff dataset that considers regional air temperature increases of 0, 2, 4 and 6 °C to represent historical, near-term, mid-term and far-term (end-of-century) warming. Most major hydropower turbine flows are simulated well. Reservoir storage is also

  14. The effect of active warming in prehospital trauma care during road and air ambulance transportation - a clinical randomized trial

    Directory of Open Access Journals (Sweden)

    Naredi Peter

    2011-10-01

    Full Text Available Abstract Background Prevention and treatment of hypothermia by active warming in prehospital trauma care is recommended but scientifical evidence of its effectiveness in a clinical setting is scarce. The objective of this study was to evaluate the effect of additional active warming during road or air ambulance transportation of trauma patients. Methods Patients were assigned to either passive warming with blankets or passive warming with blankets with the addition of an active warming intervention using a large chemical heat pad applied to the upper torso. Ear canal temperature, subjective sensation of cold discomfort and vital signs were monitored. Results Mean core temperatures increased from 35.1°C (95% CI; 34.7-35.5°C to 36.0°C (95% CI; 35.7-36.3°C (p Conclusions In mildly hypothermic trauma patients, with preserved shivering capacity, adequate passive warming is an effective treatment to establish a slow rewarming rate and to reduce cold discomfort during prehospital transportation. However, the addition of active warming using a chemical heat pad applied to the torso will significantly improve thermal comfort even further and might also reduce the cold induced stress response. Trial Registration ClinicalTrials.gov: NCT01400152

  15. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area; Phadke, Amol [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Energy Technologies Area

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere, mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel. We find that implementing HFC refrigerant transition and energy efficiency improvement policies in parallel for room air conditioning, roughly doubles the benefit of either policy implemented separately. We estimate that shifting the 2030 world stock of room air conditioners from the low efficiency technology using high-GWP refrigerants to higher efficiency technology and low-GWP refrigerants in parallel would save between 340-790 gigawatts (GW) of peak load globally, which is roughly equivalent to avoiding 680-1550 peak power plants of 500MW each. This would save 0.85 GT/year annually in China equivalent to over 8 Three Gorges dams and over 0.32 GT/year annually in India equivalent to roughly twice India’s 100GW solar mission target. While there is some uncertainty associated with

  16. Responses of Contrasting Tree Functional Types to Air Warming and Drought

    Directory of Open Access Journals (Sweden)

    Elisabet Martínez-Sancho

    2017-11-01

    Full Text Available Climate change-induced rise of air temperatures and the increase of extreme climatic events, such as droughts, will largely affect plant growth and hydraulics, leading to mortality events all over the globe. In this study, we investigated the growth and hydraulic responses of seedlings of contrasting functional types. Pinus sylvestris, Quercus spp. and Castanea sativa seedlings were grown in a common garden experiment under four treatments: control, air warming, drought and their combination during two consecutive growing periods. Height and diameter increments, stomatal conductance and stem water potentials were measured during both growing seasons. Additionally, hydraulic parameters such as xylem-specific native and maximum hydraulic conductivities, and native percentage of loss of conductivity were measured at the end of the entire experiment. Our results clearly pointed to different adaptive strategies of the studied species. Scots pine displayed a relatively isohydric behavior with a strict stomata control prohibiting native embolism whereas sweet chestnut and oak as relatively anisohydric species displayed an increased loss of native conductivity as a results of low water potentials. Seasonal timing of shoot and diameter growth also differed among functional types influencing drought impacts. Additionally, the possibility of embolism reversal seemed to be limited under the study conditions.

  17. Benefits of Leapfrogging to Superefficiency and Low Global Warming Potential Refrigerants in Room Air Conditioning

    Energy Technology Data Exchange (ETDEWEB)

    Shah, Nihar K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wei, Max [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Letschert, Virginie [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Phadke, Amol A. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-10-01

    Hydrofluorocarbons (HFCs) emitted from uses such as refrigerants and thermal insulating foam, are now the fastest growing greenhouse gases (GHGs), with global warming potentials (GWP) thousands of times higher than carbon dioxide (CO2). Because of the short lifetime of these molecules in the atmosphere,1 mitigating the amount of these short-lived climate pollutants (SLCPs) provides a faster path to climate change mitigation than control of CO2 alone. This has led to proposals from Africa, Europe, India, Island States, and North America to amend the Montreal Protocol on Substances that Deplete the Ozone Layer (Montreal Protocol) to phase-down high-GWP HFCs. Simultaneously, energy efficiency market transformation programs such as standards, labeling and incentive programs are endeavoring to improve the energy efficiency for refrigeration and air conditioning equipment to provide life cycle cost, energy, GHG, and peak load savings. In this paper we provide an estimate of the magnitude of such GHG and peak electric load savings potential, for room air conditioning, if the refrigerant transition and energy efficiency improvement policies are implemented either separately or in parallel.

  18. The antifungal activity of essential oils in combination with warm air flow against postharvest phytopathogenic fungi in apples

    Czech Academy of Sciences Publication Activity Database

    Franková, A.; Šmíd, J.; Bernardos, A.; Finkousová, A.; Maršík, Petr; Novotný, D.; Legarová, V.; Půlkrábek, J.; Klouček, P.

    2016-01-01

    Roč. 68, OCT (2016), s. 62-68 ISSN 0956-7135 R&D Projects: GA MŠk(CZ) LD13013 Institutional support: RVO:61389030 Keywords : Essential oil vapor phase * Antifungal * Warm air flow Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.496, year: 2016

  19. WASTE HEAT RECOVERY IN HEAT PUMP SYSTEMS: SOLUTION TO REDUCE GLOBAL WARMING

    Directory of Open Access Journals (Sweden)

    Y. Baradey

    2015-11-01

    Full Text Available Energy conversion technologies, where waste heat recovery systems are included, have received significant attention in recent years due to reasons that include depletion of fossil fuel, increasing oil prices, changes in climatic conditions, and global warming. For low temperature applications, there are many sources of thermal waste heat, and several recovery systems and potential useful applications have been proposed by researchers [1-4]. In addition, many types of equipment are used to recover waste thermal energy from different systems at low, medium, and high temperature applications, such as heat exchangers, waste heat recovery boiler, thermo-electric generators, and recuperators. In this paper, the focus is on waste heat recovery from air conditioners, and an efficient application of these energy resources. Integration of solar energy with heat pump technologies and major factors that affect the feasibility of heat recovery systems have been studied and reviewed as well. KEYWORDS: waste heat recovery; heat pump.

  20. Forced-air warming: a source of airborne contamination in the operating room?

    Directory of Open Access Journals (Sweden)

    David Leaper

    2009-12-01

    Full Text Available Forced-air-warming (FAW is an effective and widely used means for maintaining surgical normothermia, but FAW also has the potential to generate and mobilize airborne contamination in the operating room. We measured the emission of viable and non-viable forms of airborne contamination from an arbitrary selection of FAW blowers (n=25 in the operating room. A laser particle counter measured particulate concentrations of the air near the intake filter and in the distal hose airstream. Filtration efficiency was calculated as the reduction in particulate concentration in the distal hose airstream relative to that of the intake. Microbial colonization of the FAW blower’s internal hose surfaces was assessed by culturing the microorganisms recovered through swabbing (n=17 and rinsing (n=9 techniques. Particle counting revealed that 24% of FAW blowers were emitting significant levels of internally generated airborne contamination in the 0.5 to 5.0 mm size range, evidenced by a steep decrease in FAW blower filtration efficiency for particles 0.5 to 5.0 mm in size. The particle size-range-specific reduction in efficiency could not be explained by the filtration properties of the intake filter. Instead, the reduction was found to be caused by size-range-specific particle generation within the FAW blowers. Microorganisms were detected on the internal air path surfaces of 94% of FAW blowers. The design of FAW blowers was found to be questionable for preventing the build-up of internal contamination and the emission of airborne contamination into the operating room. Although we did not evaluate the link between FAW and surgical site infection rates, a significant percentage of FAW blowers with positive microbial cultures were emitting internally generated airborne contamination within the size range of free floating bacteria and fungi (<4 mm that could, conceivably, settle onto the surgical site.

  1. Clinical considerations in the use of forced-air warming blankets during orthognathic surgery to avoid postanesthetic shivering

    Science.gov (United States)

    Park, Fiona Daye; Park, Sookyung; Chi, Seong-In; Kim, Hyun Jeong; Kim, Hye-Jung; Han, Jin-Hee; Han, Hee-Jeong; Lee, Eun-Hee

    2015-01-01

    Background During head and neck surgery including orthognathic surgery, mild intraoperative hypothermia occurs frequently. Hypothermia is associated with postanesthetic shivering, which may increase the risk of other postoperative complications. To improve intraoperative thermoregulation, devices such as forced-air warming blankets can be applied. This study aimed to evaluate the effect of supplemental forced-air warming blankets in preventing postanesthetic shivering. Methods This retrospective study included 113 patients who underwent orthognathic surgery between March and September 2015. According to the active warming method utilized during surgery, patients were divided into two groups: Group W (n = 55), circulating-water mattress; and Group F (n = 58), circulating-water mattress and forced-air warming blanket. Surgical notes and anesthesia and recovery room records were evaluated. Results Initial axillary temperatures did not significantly differ between groups (Group W = 35.9 ± 0.7℃, Group F = 35.8 ± 0.6℃). However, at the end of surgery, the temperatures in Group W were significantly lower than those in Group F (35.2 ± 0.5℃ and 36.2 ± 0.5℃, respectively, P = 0.04). The average body temperatures in Groups W and F were, respectively, 35.9 ± 0.5℃ and 36.2 ± 0.5℃ (P = 0.0001). In Group W, 24 patients (43.6%) experienced postanesthetic shivering, while in Group F, only 12 (20.7%) patients required treatment for postanesthetic shivering (P = 0.009, odds ratio = 0.333, 95% confidence interval: 0.147–0.772). Conclusions Additional use of forced-air warming blankets in orthognathic surgery was superior in maintaining normothermia and reduced the incidence of postanesthetic shivering. PMID:28879279

  2. Evaluation of Proposed Solutions to Global Warming, Air Pollution, and Energy Security

    Science.gov (United States)

    Jacobson, M. Z.

    2008-12-01

    This study reviews and ranks major proposed solutions to global warming, air pollution mortality, and energy security while considering other impacts of the proposed solutions, such as on water supply, land use, wildlife, resource availability, thermal pollution, water chemical pollution, nuclear proliferation, and undernutrition. Nine electric power sources and two liquid fuel options are considered. The electricity sources include solar-photovoltaics (PV), concentrated solar power (CSP), wind, geothermal, hydroelectric, wave, tidal, nuclear, and coal with carbon capture and storage (CCS) technology. The liquid fuel options include corn-E85 and cellulosic E85. To place the electric and liquid fuel sources on an equal footing, we examine their comparative abilities to address the problems mentioned by powering new-technology vehicles, including battery-electric vehicles (BEVs), hydrogen fuel cell vehicles (HFCVs), and flex-fuel vehicles run on E85. Twelve combinations of energy source-vehicle type are considered. Upon ranking and weighting each combination with respect to each of 11 impact categories, four clear divisions of ranking, or tiers, emerge. Tier 1 (highest-ranked) includes wind-BEVs and wind-HFCVs. Tier 2 includes CSP-BEVs, geothermal-BEVs, PV-BEVs, tidal-BEVs, and wave-BEVs. Tier 3 includes hydro-BEVs, nuclear-BEVs, and CCS-BEVs. Tier 4 includes corn- and cellulosic-E85. Wind-BEVs ranked first in six out of 11 categories, including the two most important, mortality and climate damage reduction. Although HFCVs are less efficient than BEVs, wind- HFCVs ranked second among all combinations. Tier 2 options provide significant benefits and are recommended. Tier 3 options are less desirable. However, hydroelectricity, which was ranked ahead of coal- CCS and nuclear with respect to climate and health, is an excellent load balancer, thus strongly recommended. The Tier-4 combinations (cellulosic- and corn-E85) were ranked lowest overall and with respect to

  3. Safety-related control air systems

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    This Standard applies to those portions of the control air system that furnish air required to support, control, or operate systems or portions of systems that are safety related in nuclear power plants. This Standard relates only to the air supply system(s) for safety-related air operated devices and does not apply to the safety-related air operated device or to air operated actuators for such devices. The objectives of this Standard are to provide (1) minimum system design requirements for equipment, piping, instruments, controls, and wiring that constitute the air supply system; and (2) the system and component testing and maintenance requirements

  4. Constructing warm inflationary model in brane–antibrane system

    Energy Technology Data Exchange (ETDEWEB)

    Setare, M.R., E-mail: rezakord@ipm.ir [Department of Science, Campus of Bijar, University of Kurdistan, Bijar (Iran, Islamic Republic of); Sepehri, A., E-mail: alireza.sepehri@uk.ac.ir [Faculty of Physics, Shahid Bahonar University, P.O. Box 76175, Kerman (Iran, Islamic Republic of); Kamali, V., E-mail: Vkamali@basu.ac.ir [Department of Physics, Faculty of Science, Bu-Ali Sina University, Hamedan, 65178 (Iran, Islamic Republic of)

    2014-07-30

    Recently, various observational data predicted a possibility that inflation may naturally occur in a warm region. In this scenario, radiation is produced during the inflation epoch and reheating is avoided. The main question arises as to what is the origin of warm inflation in 4D universe? We answer this question in brane–antibrane system. We propose a model that allows all cosmological parameters like the scale factor a, the Hubble parameter H and phantom energy density depend on the equation of state parameter in transverse dimension between two branes. Thus, an enhancement in these parameters can be a signature of some evolutions in extra dimension. In our model, the expansion of 4D universe is controlled by the separation distance between branes and evolves from non-phantom phase to phantom one. Consequently, phantom-dominated era of the universe accelerates and ends up in big-rip singularity. Also, we show that as the tachyon potential increases, the effect of interaction between branes on the 4D universe expansion becomes systematically more effective, because at higher energies there exist more channels for flowing energy from extra dimension to other four dimensions. Finally, we test our model against WMAP and Planck data and obtain the ripping time. According to experimental data, N≃50 case leads to n{sub s}≃0.96, where N and n{sub s} are the number e-folds and the spectral index respectively. This standard case may be found in 0.01

  5. Air pollution control and decreasing new particle formation lead to strong climate warming

    Directory of Open Access Journals (Sweden)

    R. Makkonen

    2012-02-01

    Full Text Available The number concentration of cloud droplets determines several climatically relevant cloud properties. A major cause for the high uncertainty in the indirect aerosol forcing is the availability of cloud condensation nuclei (CCN, which in turn is highly sensitive to atmospheric new particle formation. Here we present the effect of new particle formation on anthropogenic aerosol forcing in present-day (year 2000 and future (year 2100 conditions. The present-day total aerosol forcing is increased from −1.0 W m−2 to −1.6 W m−2 when nucleation is introduced into the model. Nucleation doubles the change in aerosol forcing between years 2000 and 2100, from +0.6 W m−2 to +1.4 W m−2. Two climate feedbacks are studied, resulting in additional negative forcings of −0.1 W m−2 (+10% DMS emissions in year 2100 and −0.5 W m−2 (+50% BVOC emissions in year 2100. With the total aerosol forcing diminishing in response to air pollution control measures taking effect, warming from increased greenhouse gas concentrations can potentially increase at a very rapid rate.

  6. Warm layer and cool skin corrections for bulk water temperature measurements for air-sea interaction studies

    Science.gov (United States)

    Alappattu, Denny P.; Wang, Qing; Yamaguchi, Ryan; Lind, Richard J.; Reynolds, Mike; Christman, Adam J.

    2017-08-01

    The sea surface temperature (SST) relevant to air-sea interaction studies is the temperature immediately adjacent to the air, referred to as skin SST. Generally, SST measurements from ships and buoys are taken at depths varies from several centimeters to 5 m below the surface. These measurements, known as bulk SST, can differ from skin SST up to O(1°C). Shipboard bulk and skin SST measurements were made during the Coupled Air-Sea Processes and Electromagnetic ducting Research east coast field campaign (CASPER-East). An Infrared SST Autonomous Radiometer (ISAR) recorded skin SST, while R/V Sharp's Surface Mapping System (SMS) provided bulk SST from 1 m water depth. Since the ISAR is sensitive to sea spray and rain, missing skin SST data occurred in these conditions. However, SMS measurement is less affected by adverse weather and provided continuous bulk SST measurements. It is desirable to correct the bulk SST to obtain a good representation of the skin SST, which is the objective of this research. Bulk-skin SST difference has been examined with respect to meteorological factors associated with cool skin and diurnal warm layers. Strong influences of wind speed, diurnal effects, and net longwave radiation flux on temperature difference are noticed. A three-step scheme is established to correct for wind effect, diurnal variability, and then for dependency on net longwave radiation flux. Scheme is tested and compared to existing correction schemes. This method is able to effectively compensate for multiple factors acting to modify bulk SST measurements over the range of conditions experienced during CASPER-East.

  7. Magnus air turbine system

    Science.gov (United States)

    Hanson, Thomas F.

    1982-01-01

    A Magnus effect windmill for generating electrical power is disclosed. A large nacelle-hub mounted pivotally (in Azimuth) atop a support tower carries, in the example disclosed, three elongated barrels arranged in a vertical plane and extending symmetrically radially outwardly from the nacelle. The system provides spin energy to the barrels by internal mechanical coupling in the proper sense to cause, in reaction to an incident wind, a rotational torque of a predetermined sense on the hub. The rotating hub carries a set of power take-off rollers which ride on a stationary circular track in the nacelle. Shafts carry the power, given to the rollers by the wind driven hub, to a central collector or accumulator gear assembly whose output is divided to drive the spin mechanism for the Magnus barrels and the main electric generator. A planetary gear assembly is interposed between the collector gears and the spin mechanism functioning as a differential which is also connected to an auxiliary electric motor whereby power to the spin mechanism may selectively be provided by the motor. Generally, the motor provides initial spin to the barrels for start-up after which the motor is braked and the spin mechanism is driven as though by a fixed ratio coupling from the rotor hub. During high wind or other unusual conditions, the auxiliary motor may be unbraked and excess spin power may be used to operate the motor as a generator of additional electrical output. Interposed between the collector gears of the rotating hub and the main electric generator is a novel variable speed drive-fly wheel system which is driven by the variable speed of the wind driven rotor and which, in turn, drives the main electric generator at constant angular speed. Reference is made to the complete specification for disclosure of other novel aspects of the system such as, for example, the aerodynamic and structural aspects of the novel Magnus barrels as well as novel gearing and other power coupling

  8. Forced-Air Warming Provides Better Control of Body Temperature in Porcine Surgical Patients.

    Science.gov (United States)

    Dent, Brian T; Stevens, Karla A; Clymer, Jeffrey W

    2016-09-09

    Background: Maintaining normothermia during porcine surgery is critical in ensuring subject welfare and recovery, reducing the risk of immune system compromise and surgical-site infection that can result from hypothermia. In humans, various methods of patient heating have been demonstrated to be useful, but less evaluation has been performed in techniques to prevent hypothermia perioperatively in pigs. Methods: We compared body temperature regulation during surgery before and after modification of the ambient temperature of the operating laboratories. Three different methods of heating were then compared; a standard circulating water mattress, a resistive fabric blanket, and a forced hot air system. The primary measure was percentage of temperature readings outside a specification range of 36.7-40.0 °C. Results: Tighter control of the ambient temperature while using a circulating water mattress reduced the occurrence of out-of-specification body temperature readings from 20.8% to 5.0%, with most of these the result of hypothermia. Use of a resistive fabric blanket further reduced out-of-specification readings to 1.5%, with a slight increase in the occurrence of hyperthermia. Use of a forced air system reduced out-of-specification readings to less 0.1%. Conclusions: Maintenance of normothermia perioperatively in pig can be improved by tightly controlling ambient temperatures. Use of a resistive blanket or a forced air system can lead to better control than a circulating water mattress, with the forced air system providing a faster response to temperature variations and less chance of hyperthermia.

  9. Forced-Air Warming Provides Better Control of Body Temperature in Porcine Surgical Patients

    Directory of Open Access Journals (Sweden)

    Brian T. Dent

    2016-09-01

    Full Text Available Background: Maintaining normothermia during porcine surgery is critical in ensuring subject welfare and recovery, reducing the risk of immune system compromise and surgical-site infection that can result from hypothermia. In humans, various methods of patient heating have been demonstrated to be useful, but less evaluation has been performed in techniques to prevent hypothermia perioperatively in pigs. Methods: We compared body temperature regulation during surgery before and after modification of the ambient temperature of the operating laboratories. Three different methods of heating were then compared; a standard circulating water mattress, a resistive fabric blanket, and a forced hot air system. The primary measure was percentage of temperature readings outside a specification range of 36.7–40.0 °C. Results: Tighter control of the ambient temperature while using a circulating water mattress reduced the occurrence of out-of-specification body temperature readings from 20.8% to 5.0%, with most of these the result of hypothermia. Use of a resistive fabric blanket further reduced out-of-specification readings to 1.5%, with a slight increase in the occurrence of hyperthermia. Use of a forced air system reduced out-of-specification readings to less 0.1%. Conclusions: Maintenance of normothermia perioperatively in pig can be improved by tightly controlling ambient temperatures. Use of a resistive blanket or a forced air system can lead to better control than a circulating water mattress, with the forced air system providing a faster response to temperature variations and less chance of hyperthermia.

  10. Effects of warm air drying on water sorption, solubility, and adhesive strength of simplified etch-and-rinse adhesives.

    Science.gov (United States)

    Reis, Alessandra; Wambier, Leticia; Malaquias, Tamirez; Wambier, Denise S; Loguercio, Alessandro D

    2013-02-01

    To evaluate the effects of the temperature of air used for solvent evaporation on water sorption, solubility, and ultimate tensile strength (UTS) of simplified etch-and-rinse adhesives. Four commercial simplified etch-and-rinse adhesives (Adper Single Bond 2 [SB]; Te Econom [TE]; XP Bond [XP] and Ambar [AM]) were selected. Disk-shaped specimens were prepared by dispensing the uncured resin into a mold (5.8 mm x 0.8 mm). Solvent evaporation was performed using a warm (60°C) or cold (20°C) air stream for 40 s. After desiccation, the cured specimens were weighed and then stored in distilled water for evaluation of the water diffusion kinetics over a 28-day period. For the UTS measurement, hourglass-shaped specimens of adhesives were prepared and tested in tension. The data from each test were evaluated with two-way ANOVA and Tukey's test at a confidence level of 95%. Water sorption and solubility varied significantly between materials, but no significant difference was observed between warm and cold conditions (p > 0.05). TE and AM showed the lowest water sorption and solubility (p < 0.05). For SB, TE, and XP, the use of a warm air stream resulted in higher ultimate tensile strength (p < 0.05) in both experimental conditions. The water sorption and solubility of the materials seem to be more influenced by their composition than by the temperature used for solvent evaporation. For some adhesives, the use of a warm air stream can yield higher ultimate tensile strength.

  11. Warm and Humid Air Blowing over Cold Water - Grand Banks Fog

    Science.gov (United States)

    Taylor, P.; Weng, W.

    2016-12-01

    The condensation of water vapour into droplets and the formation of fog in the Earth's atmospheric boundary layer involves a complex balance between horizontal advection and vertical turbulent mixing of heat and water vapour, cloud microphysical processes and radiative transfers of heat, plus the impact of water droplets, and sometimes ice crystals, on visibility. It is a phenomenon which has been studied for many years in a variety of contexts. On land, surface cooling of the ground via long wave radiation at night is often the trigger and a number of 1-D (height and time dependent) radiative fog models have been developed. Over the waters offshore from Newfoundland a key factor is the advection of moist air from over warm gulf stream waters to colder Labrador current water - an internal boundary-layer problem. Some basic properties can be learned from a steady state 2-D (x-z) model.The WTS (Weng, Taylor and Salmon, 2010, J. Wind Eng. Ind. Aerodyn. 98, 121-132 ) model of flow above changes in surface conditions has been used to investigate planetary boundary-layer flow over water with spatial changes in temperature, and to investigate situations leading to saturation and fog formation. Our turbulence closure includes the turbulent kinetic energy equation but we prefer to specify a height, surface roughness, Rossby number and local stability dependent, "master" length scale instead of a somewhat empirical dissipation or similar equation. Results show that fog can develop and extent to heights of order 100m in some conditions, depending on upstream profiles of wind, temperature and mixing ratio, and on solar radiation and the horizontal variations in water surface temperature.Next steps will involve validation against data being collected (by AMEC-Foster Wheeler in the Hibernia Management and Development Company Metocean project) over the Grand Banks and an interface with WRF and high resolution sea surface temperature data for forecasting fog conditions over the

  12. Air filtration in HVAC systems

    CERN Document Server

    Ginestet, Alain; Tronville, Paolo; Hyttinen, Marko

    2010-01-01

    Air filtration Guidebook will help the designer and user to understand the background and criteria for air filtration, how to select air filters and avoid problems associated with hygienic and other conditions at operation of air filters. The selection of air filters is based on external conditions such as levels of existing pollutants, indoor air quality and energy efficiency requirements.

  13. Active body surface warming systems for preventing complications caused by inadvertent perioperative hypothermia in adults.

    Science.gov (United States)

    Madrid, Eva; Urrútia, Gerard; Roqué i Figuls, Marta; Pardo-Hernandez, Hector; Campos, Juan Manuel; Paniagua, Pilar; Maestre, Luz; Alonso-Coello, Pablo

    2016-04-21

    Inadvertent perioperative hypothermia is a phenomenon that can occur as a result of the suppression of the central mechanisms of temperature regulation due to anaesthesia, and of prolonged exposure of large surfaces of skin to cold temperatures in operating rooms. Inadvertent perioperative hypothermia has been associated with clinical complications such as surgical site infection and wound-healing delay, increased bleeding or cardiovascular events. One of the most frequently used techniques to prevent inadvertent perioperative hypothermia is active body surface warming systems (ABSW), which generate heat mechanically (heating of air, water or gels) that is transferred to the patient via skin contact. To assess the effectiveness of pre- or intraoperative active body surface warming systems (ABSW), or both, to prevent perioperative complications from unintended hypothermia during surgery in adults. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; Issue 9, 2015); MEDLINE (PubMed) (1964 to October 2015), EMBASE (Ovid) (1980 to October 2015), and CINAHL (Ovid) (1982 to October 2015). We included randomized controlled trials (RCTs) that compared an ABSW system aimed at maintaining normothermia perioperatively against a control or against any other ABSW system. Eligible studies also had to include relevant clinical outcomes other than measuring temperature alone. Several authors, by pairs, screened references and determined eligibility, extracted data, and assessed risks of bias. We resolved disagreements by discussion and consensus, with the collaboration of a third author. We included 67 trials with 5438 participants that comprised 79 comparisons. Forty-five RCTs compared ABSW versus control, whereas 18 compared two different types of ABSW, and 10 compared two different techniques to administer the same type of ABSW. Forced-air warming (FAW) was by far the most studied intervention.Trials varied widely regarding whether the interventions were

  14. Keeping warm with fur in cold water: entrainment of air in hairy surfaces

    Science.gov (United States)

    Nasto, Alice; Regli, Marianne; Brun, Pierre-Thomas; Clanet, Christophe; Hosoi, Anette

    2015-11-01

    Instead of relying on a thick layer of body fat for insulation as many aquatic mammals do, fur seals and otters trap air in their dense fur for insulation in cold water. Using a combination of model experiments and theory, we rationalize this mechanism of air trapping underwater for thermoregulation. For the model experiments, hairy surfaces are fabricated using laser cut molds and casting samples with PDMS. Modeling the hairy texture as a network of capillary tubes, the imbibition speed of water into the hairs is obtained through a balance of hydrostatic pressure and viscous stress. In this scenario, the bending of the hairs and capillary forces are negligible. The maximum diving depth that can be achieved before the hairs are wetted to the roots is predicted from a comparison of the diving speed and imbibition speed. The amount of air that is entrained in hairy surfaces is greater than what is expected for classic Landau-Levich-Derjaguin plate plunging. A phase diagram with the parameters from experiments and biological data allows a comparison of the model system and animals.

  15. Warm Dry Weather Conditions Cause of 2016 Fort McMurray Wild Forest Fire and Associated Air Quality

    Science.gov (United States)

    de Azevedo, S. C.; Singh, R. P.; da Silva, E. A., Sr.

    2016-12-01

    The climate change is evident from the increasing temperature around the world, day to day life and increasing frequency of natural hazards. The warm and dry conditions are the cause of frequent forest fires around the globe. Forest fires severely affect the air quality and human health. Multi sensor satellites and dense network of ground stations provide information about vegetation health, meteorological, air quality and atmospheric parameters. We have carried out detailed analysis of satellite and ground data of wild forest fire that occurred in May 2016 in Fort McMurray, Alberta, Canada. This wild forest fire destroyed 10 per cent of Fort McMurray's housing and forced more than 90,000 people to evacuate the surrounding areas. Our results show that the warm and dry conditions with low rainfall were the cause of Fort McMurray wild fire. The air quality parameters (particulate matter, CO, ozone, NO2, methane) and greenhouse gases measured from Atmospheric Infrared Sounder (AIRS) satellite show enhanced levels soon after the forest fire. The emissions from the forest fire affected health of population living in surrounding areas up to 300 km radius.

  16. Infrared heater system for warming tropical forest understory plants and soils

    Science.gov (United States)

    Bruce A. Kimball; Aura M. Alonso-Rodríguez; Molly A. Cavaleri; Sasha C. Reed; Grizelle González; Tana E. Wood

    2018-01-01

    The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for the Tropical Responses...

  17. Quantifying the Sensitivity of Precipitation to the Long-term Warming Trend and Interannual Variability of Air Temperature over China

    Science.gov (United States)

    Zhou, C.; Wang, K.

    2016-12-01

    Large discrepancies in precipitation sensitivities to the warming trend have been widely reported, likely due to the enormous interannual variability of precipitation, e.g., representing over 90% of total precipitation variance in China. So we first elucidate precipitation sensitivities to the long-term warming trend and interannual variability of air temperature (Ta) based on the latest daily datasets from approximately 2000 stations in China from 1961 to 2014. The detailed results are that: 1) dry, trace and light precipitation days have stronger sensitivities to the warming trend than Ta interannual variability, i.e., 14.1%/K, -35.7%/K and -14.6%/K vs. 2.7%/K, -7.9%/K and -3.1%/K, respectively. Consequently, total precipitation frequency has significant sensitivities to the warming trend (-18.5%/K) and interannual variability (-3.6%/K). 2) A warming trend boosts precipitation intensity to varying extents, especially light precipitation (9.8%/K), but very heavy precipitation intensity is dominated by interannual variability (3.7%/K), especially in cold seasons (8.0%/K). Consequently, total precipitation intensity increases by 13.1%/K for the warming trend and 3.3%/K for interannual variability. 3) Reconciling precipitation frequency with intensity, moderate and heavy precipitation amounts are dominated by their frequencies. Total precipitation amount has little sensitivity to the warming trend (0.3%/K), and the consequent trend in China is limited (0.34%/decade). Nevertheless, the uneven changes in precipitation frequency and intensity greatly influence soil moisture, vegetation growth and crop productivity. What's more, precipitation sensitivities for interannual variability linearly correlate with those for the warming trend, with a correlation coefficient of 0.81 (p=0.00), providing a way to diagnose and evaluate model simulations of interannual variability of precipitation and also to refine the interannual variability of precipitation under good skill of

  18. Estimation of the Carbon Footprint and Global Warming Potential in Rice Production Systems

    International Nuclear Information System (INIS)

    Dastan, S.; Soltani, F.; Noormohamadi, G.; Madani, H.; Yadi, R.

    2016-01-01

    Optimal management approaches can be adopted in order to increase crop productivity and lower the carbon footprint of grain products. The objective of this study was to estimate the carbon (C) footprint and global warming potential of rice production systems. In this experiment, rice production systems (including SRI, improved and conventional) were studied. All activities, field operations and data in production methods and at different input rates were monitored and recorded during 2012. Results showed that average global warming potential across production systems was equal to 2803.25 kg CO 2 -eq ha-1. The highest and least global warming potential were observed in the SRI and conventional systems, respectively. global warming potential per unit energy input was the least and most in SRI and conventional systems, respectively. Also, the SRI and conventional systems had the maximum and minimum global warming potential per unit energy output, respectively. SRI and conventional system had the greatest and least global warming potential per unit energy output, respectively. Therefore, the optimal management approach found in SRI resulted in a reduction in GHGs, global warming potential and the carbon footprint.

  19. Strategy Guideline. Compact Air Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Burdick, Arlan [IBACOS, Inc., Pittsburgh, PA (United States)

    2013-06-01

    This guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  20. Comparison between Different Air Distribution Systems

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    The aim of an air conditioning system is to remove excess heat in a room and replace room air with fresh air to obtain a high air quality. It is not sufficient to remove heat and contaminated air, it is also necessary to distribute and control the air movement in the room to create thermal comfort...... in the occupied zone. Most air distribution systems are based on mixing ventilation with ceiling or wall-mounted diffusers or on displacement ventilation with wall-mounted low velocity diffusers. New principles for room air distribution were introduced during the last decades, as the textile terminals mounted...... in the ceiling and radial diffusers with swirling flow also mounted in the ceiling. This paper addresses five air distribution systems in all, namely mixing ventilation from a wallmounted terminal, mixing ventilation from a ceiling-mounted diffuser, mixing ventilation from a ceiling-mounted diffuser...

  1. Air Mass Origin in the Arctic and its Response to Future Warming

    Science.gov (United States)

    Orbe, Clara; Newman, Paul A.; Waugh, Darryn W.; Holzer, Mark; Oman, Luke; Polvani, Lorenzo M.; Li, Feng

    2014-01-01

    We present the first climatology of air mass origin in the Arctic in terms of rigorously defined air mass fractions that partition air according to where it last contacted the planetary boundary layer (PBL). Results from a present-day climate integration of the GEOSCCM general circulation model reveal that the Arctic lower troposphere below 700 mb is dominated year round by air whose last PBL contact occurred poleward of 60degN, (Arctic air, or air of Arctic origin). By comparison, approx. 63% of the Arctic troposphere above 700 mb originates in the NH midlatitude PBL, (midlatitude air). Although seasonal changes in the total fraction of midlatitude air are small, there are dramatic changes in where that air last contacted the PBL, especially above 700 mb. Specifically, during winter air in the Arctic originates preferentially over the oceans, approx. 26% in the East Pacific, and approx. 20% in the Atlantic PBL. By comparison, during summer air in the Arctic last contacted the midlatitude PBL primarily over land, overwhelmingly so in Asia (approx. 40 %) and, to a lesser extent, in North America (approx. 24%). Seasonal changes in air-mass origin are interpreted in terms of seasonal variations in the large-scale ventilation of the midlatitude boundary layer and lower troposphere, namely changes in the midlatitude tropospheric jet and associated transient eddies during winter and large scale convective motions over midlatitudes during summer.

  2. The major stratospheric final warming in 2016: dispersal of vortex air and termination of Arctic chemical ozone loss

    Directory of Open Access Journals (Sweden)

    G. L. Manney

    2016-12-01

    Full Text Available The 2015/16 Northern Hemisphere winter stratosphere appeared to have the greatest potential yet seen for record Arctic ozone loss. Temperatures in the Arctic lower stratosphere were at record lows from December 2015 through early February 2016, with an unprecedented period of temperatures below ice polar stratospheric cloud thresholds. Trace gas measurements from the Aura Microwave Limb Sounder (MLS show that exceptional denitrification and dehydration, as well as extensive chlorine activation, occurred throughout the polar vortex. Ozone decreases in 2015/16 began earlier and proceeded more rapidly than those in 2010/11, a winter that saw unprecedented Arctic ozone loss. However, on 5–6 March 2016 a major final sudden stratospheric warming ("major final warming", MFW began. By mid-March, the mid-stratospheric vortex split after being displaced far off the pole. The resulting offspring vortices decayed rapidly preceding the full breakdown of the vortex by early April. In the lower stratosphere, the period of temperatures low enough for chlorine activation ended nearly a month earlier than that in 2011 because of the MFW. Ozone loss rates were thus kept in check because there was less sunlight during the cold period. Although the winter mean volume of air in which chemical ozone loss could occur was as large as that in 2010/11, observed ozone values did not drop to the persistently low values reached in 2011.We use MLS trace gas measurements, as well as mixing and polar vortex diagnostics based on meteorological fields, to show how the timing and intensity of the MFW and its impact on transport and mixing halted chemical ozone loss. Our detailed characterization of the polar vortex breakdown includes investigations of individual offspring vortices and the origins and fate of air within them. Comparisons of mixing diagnostics with lower-stratospheric N2O and middle-stratospheric CO from MLS (long-lived tracers show rapid vortex erosion and

  3. Comfort, Energy Efficiency and Adoption of Personal Cooling Systems in Warm Environments: A Field Experimental Study.

    Science.gov (United States)

    He, Yingdong; Li, Nianping; Wang, Xiang; He, Meiling; He, De

    2017-11-17

    It is well known that personal cooling improves thermal comfort and save energy. This study aims to: (1) compare different personal cooling systems and (2) understand what influences users' willingness to adopt them. A series of experiments on several types of personal cooling systems, which included physical measurements, questionnaires and feedback, was conducted in a real office environment. The obtained results showed that personal cooling improved comfort of participants in warm environments. Then an improved index was proposed and used to compare different types of personal cooling systems in terms of comfort and energy efficiency simultaneously. According to the improved index, desk fans were highly energy-efficient, while the hybrid personal cooling (the combination of radiant cooling desk and desk fan) consumed more energy but showed advantages of extending the comfortable temperature range. Moreover, if personal cooling was free, most participants were willing to adopt it and the effectiveness was the main factor influencing their willingness, whereas if participants had to pay, they probably refused to adopt it due to the cost and the availability of conventional air conditioners. Thus, providing effective and free personal cooling systems should be regarded as a better way for its wider application.

  4. Strategy Guideline: Compact Air Distribution Systems

    Energy Technology Data Exchange (ETDEWEB)

    Burdick, A.

    2013-06-01

    This Strategy Guideline discusses the benefits and challenges of using a compact air distribution system to handle the reduced loads and reduced air volume needed to condition the space within an energy efficient home. Traditional systems sized by 'rule of thumb' (i.e., 1 ton of cooling per 400 ft2 of floor space) that 'wash' the exterior walls with conditioned air from floor registers cannot provide appropriate air mixing and moisture removal in low-load homes. A compact air distribution system locates the HVAC equipment centrally with shorter ducts run to interior walls, and ceiling supply outlets throw the air toward the exterior walls along the ceiling plane; alternatively, high sidewall supply outlets throw the air toward the exterior walls. Potential drawbacks include resistance from installing contractors or code officials who are unfamiliar with compact air distribution systems, as well as a lack of availability of low-cost high sidewall or ceiling supply outlets to meet the low air volumes with good throw characteristics. The decision criteria for a compact air distribution system must be determined early in the whole-house design process, considering both supply and return air design. However, careful installation of a compact air distribution system can result in lower material costs from smaller equipment, shorter duct runs, and fewer outlets; increased installation efficiencies, including ease of fitting the system into conditioned space; lower loads on a better balanced HVAC system, and overall improved energy efficiency of the home.

  5. Infrared heater system for warming tropical forest understory plants and soils.

    Science.gov (United States)

    Kimball, Bruce A; Alonso-Rodríguez, Aura M; Cavaleri, Molly A; Reed, Sasha C; González, Grizelle; Wood, Tana E

    2018-02-01

    The response of tropical forests to global warming is one of the largest uncertainties in predicting the future carbon balance of Earth. To determine the likely effects of elevated temperatures on tropical forest understory plants and soils, as well as other ecosystems, an infrared (IR) heater system was developed to provide in situ warming for the Tropical Responses to Altered Climate Experiment (TRACE) in the Luquillo Experimental Forest in Puerto Rico. Three replicate heated 4-m-diameter plots were warmed to maintain a 4°C increase in understory vegetation compared to three unheated control plots, as sensed by IR thermometers. The equipment was larger than any used previously and was subjected to challenges different from those of many temperate ecosystem warming systems, including frequent power surges and outages, high humidity, heavy rains, hurricanes, saturated clayey soils, and steep slopes. The system was able to maintain the target 4.0°C increase in hourly average vegetation temperatures to within ± 0.1°C. The vegetation was heterogeneous and on a 21° slope, which decreased uniformity of the warming treatment on the plots; yet, the green leaves were fairly uniformly warmed, and there was little difference among 0-10 cm depth soil temperatures at the plot centers, edges, and midway between. Soil temperatures at the 40-50 cm depth increased about 3°C compared to the controls after a month of warming. As expected, the soil in the heated plots dried faster than that of the control plots, but the average soil moisture remained adequate for the plants. The TRACE heating system produced an adequately uniform warming precisely controlled down to at least 50-cm soil depth, thereby creating a treatment that allows for assessing mechanistic responses of tropical plants and soil to warming, with applicability to other ecosystems. No physical obstacles to scaling the approach to taller vegetation (i.e., trees) and larger plots were observed.

  6. Experimental study of air distribution and ventilation effectiveness in a room heated by warm air and/or floor heating

    DEFF Research Database (Denmark)

    Simone, Angela; Olesen, Bjarne W.; Krajčík, Michal

    2010-01-01

    The levels of required ventilation depend on the criteria for indoor air quality in existing standards and guidelines. On top of that, the resulting ventilation in air changes per hour is depending on the ventilation effectiveness. In the standard CR 1752 the recommended values for ventilation ef...

  7. Industrial Compressed Air System Energy Efficiency Guidebook.

    Energy Technology Data Exchange (ETDEWEB)

    United States. Bonneville Power Administration.

    1993-12-01

    Energy efficient design, operation and maintenance of compressed air systems in industrial plants can provide substantial reductions in electric power and other operational costs. This guidebook will help identify cost effective, energy efficiency opportunities in compressed air system design, re-design, operation and maintenance. The guidebook provides: (1) a broad overview of industrial compressed air systems, (2) methods for estimating compressed air consumption and projected air savings, (3) a description of applicable, generic energy conservation measures, and, (4) a review of some compressed air system demonstration projects that have taken place over the last two years. The primary audience for this guidebook includes plant maintenance supervisors, plant engineers, plant managers and others interested in energy management of industrial compressed air systems.

  8. THE OPTIMAL SYSTEM FOR SERIES SYSTEMS WITH WARM STANDBY COMPONENTS AND A REPAIRABLE SERVICE STATION

    Directory of Open Access Journals (Sweden)

    M. Salah EL-Sherbeny

    2009-01-01

    Full Text Available This paper deals with the reliability and availability characteristics of three different series system configurations with warm standby components and a repairable service station. The failure time of the primary and warm standby are assumed to be exponentially distributed with parameters and respectively. The repair time distribution of each server is also exponentially distributed with parameter . The breakdown time and the repair time of the service station are also assumed exponentially distributed with parameters and respectively. We derive the reliability dependent on time, availability dependent on time, the mean time to failure, , and the steady-state availability for three configurations and perform comparisons. Comparisons are made for specific values of distribution parameters and of the cost of the components. The three configurations are ranked based on: , and where is either or .

  9. Human preference and acceptance of increased air velocity to offset warm sensation at increased room temperatures

    DEFF Research Database (Denmark)

    Cattarin, Giulio; Simone, Angela; Olesen, Bjarne W.

    Previous studies have demonstrated that in summertime increased air velocities can compensate for higher room temperatures to achieve comfortable conditions. In order to increase air movement, windows opening, ceiling or desk fans can be used at the expense of relatively low energy consumption. T...

  10. Fungal colonization of air-conditioning systems

    Directory of Open Access Journals (Sweden)

    Ljaljević-Grbić Milica

    2008-01-01

    Full Text Available Fungi have been implicated as quantitatively the most important bioaerosol component of indoor air associated with contaminated air-conditioning systems. rarely, indoor fungi may cause human infections, but more commonly allergenic responses ranging from pneumonitis to asthma-like symptoms. From all air conditioner filters analyzed, 16 fungal taxa were isolated and identified. Aspergillus fumigatus causes more lethal infections worldwide than any other mold. Air-conditioning filters that adsorb moisture and volatile organics appear to provide suitable substrates for fungal colonization. It is important to stress that fungal colonization of air-conditioning systems should not be ignored, especially in hospital environments.

  11. Bavarian air monitoring system (LUEB)

    International Nuclear Information System (INIS)

    Anon.

    1982-01-01

    The LUEB has been set up for the purpose of monitoring atmopsheric pollutants and their cumulative effect on ecological subsystems. The stationary measuring points record the long-term effects of air pollution by means of biological indicators and supply short-term information on air quality and on the local meteorological conditions. In addition, there are vehicles for air pollution measurement which cover different measuring points as specified in the TA Luft (Technical Rule for Air Pollution Abatement). The measured data are evaluated by statistical methods. (orig.) [de

  12. Global warming and air transport : meeting the challenge of sustainable growth

    Science.gov (United States)

    2009-04-01

    Aviation impacts community noise footprints, air quality, water quality, energy usage and availability, and the global climate. Trends show environmental impacts from aircraft noise and aviation emissions will be a critical constraint on capacity gro...

  13. SpaceX Dragon Air Circulation System

    Science.gov (United States)

    Hernandez, Brenda; Piatrovich, Siarhei; Prina, Mauro

    2011-01-01

    The Dragon capsule is a reusable vehicle being developed by Space Exploration Technologies (SpaceX) that will provide commercial cargo transportation to the International Space Station (ISS). Dragon is designed to be a habitable module while it is berthed to ISS. As such, the Dragon Environmental Control System (ECS) consists of pressure control and pressure equalization, air sampling, fire detection, illumination, and an air circulation system. The air circulation system prevents pockets of stagnant air in Dragon that can be hazardous to the ISS crew. In addition, through the inter-module duct, the air circulation system provides fresh air from ISS into Dragon. To utilize the maximum volume of Dragon for cargo packaging, the Dragon ECS air circulation system is designed around cargo rack optimization. At the same time, the air circulation system is designed to meet the National Aeronautics Space Administration (NASA) inter-module and intra-module ventilation requirements and acoustic requirements. A flight like configuration of the Dragon capsule including the air circulation system was recently assembled for testing to assess the design for inter-module and intra-module ventilation and acoustics. The testing included the Dragon capsule, and flight configuration in the pressure section with cargo racks, lockers, all of the air circulation components, and acoustic treatment. The air circulation test was also used to verify the Computational Fluid Dynamics (CFD) model of the Dragon capsule. The CFD model included the same Dragon internal geometry that was assembled for the test. This paper will describe the Dragon air circulation system design which has been verified by testing the system and with CFD analysis.

  14. The Influence of Stratospheric Sulphate Aerosol Deployment on the Surface Air Temperature and the Risk of an Abrupt Global Warming

    Directory of Open Access Journals (Sweden)

    Roland von Glasow

    2010-12-01

    Full Text Available We used the ‘Radiative-Convective Model of the Earth-atmosphere system’ (OGIM to investigate the cooling effects induced by sulphur injections into the stratosphere. The ensemble of numerical calculations was based on the A1B scenario from the IPCC Special Report on Emissions Scenarios (SRES. Several geoengineered scenarios were analysed, including the abrupt interruption of these injections in different scenarios and at different dates. We focused on the surface air temperature (SAT anomalies induced by stratospheric sulphate aerosol generated in order to compensate future warming. Results show that continuous deployment of sulphur into the stratosphere could induce a lasting decrease in SAT. Retaining a constant aerosol loading equivalent to 6 TgS would delay the expected global warming by 53 years. Keeping the SAT constant in a context of increasing greenhouse gases (GHGs means that the aerosol loading needs to be increased by 1.9% annually. This would offset the effect of increasing GHG under the A1B scenario. A major focus of this study was on the heating rates of SAT that would arise in different scenarios in case of an abrupt cessation of sulphur injections into the stratosphere. Our model results show that heating rates after geoengineering interruption would be 15–28 times higher than in a case without geoengineering, with likely important consequences for life on Earth. Larger initial sulphate loadings induced more intense warming rates when the geoengineering was stopped at the same time. This implies that, if sulphate loading was increased to maintain constant SAT in the light of increasing GHG concentrations, the later the geoengineering interruption was to occur, the higher the heating rates would be. Consequently, geoengineering techniques like this should only be regarded as last-resort measures and require intense further research should they ever become necessary.

  15. Energy Conservation In Compressed Air Systems

    International Nuclear Information System (INIS)

    Yusuf, I.Y.; Dewu, B.B.M.

    2004-01-01

    Compressed air is an essential utility that accounts for a substantial part of the electricity consumption (bill) in most industrial plants. Although the general saying Air is free of charge is not true for compressed air, the utility's cost is not accorded the rightful importance due to its by most industries. The paper will show that the cost of 1 unit of energy in the form of compressed air is at least 5 times the cost electricity (energy input) required to produce it. The paper will also provide energy conservation tips in compressed air systems

  16. Rooftop Unitary Air Conditioner with Integral Dedicated Outdoor Air System

    Energy Technology Data Exchange (ETDEWEB)

    Tiax Llc

    2006-02-28

    Energy use of rooftop and other unitary air-conditioners in commercial applications accounts for about 1 quad (10{sup 15} Btu) of primary energy use annually in the U.S. [Reference 7]. The realization that this cooling equipment accounts for the majority of commercial building cooled floorspace and the majority also of commercial building energy use has spurred development of improved-efficiency equipment as well as development of stricter standards addressing efficiency levels. Another key market driver affecting design of rooftop air-conditioning equipment has been concern regarding comfort and the control of humidity. Trends for increases in outdoor air ventilation rates in certain applications, and the increasing concern about indoor air quality problems associated with humidity levels and moisture in buildings points to a need for improved dehumidification capability in air-conditioning equipment of all types. In many cases addressing this issue exacerbates energy efficiency, and vice versa. The integrated dedicated outdoor air system configuration developed in this project addresses both energy and comfort/humidity issues.

  17. Long range global warming

    International Nuclear Information System (INIS)

    Rolle, K.C.; Pulkrabek, W.W.; Fiedler, R.A.

    1995-01-01

    This paper explores one of the causes of global warming that is often overlooked, the direct heating of the environment by engineering systems. Most research and studies of global warming concentrate on the modification that is occurring to atmospheric air as a result of pollution gases being added by various systems; i.e., refrigerants, nitrogen oxides, ozone, hydrocarbons, halon, and others. This modification affects the thermal radiation balance between earth, sun and space, resulting in a decrease of radiation outflow and a slow rise in the earth's steady state temperature. For this reason the solution to the problem is perceived as one of cleaning up the processes and effluents that are discharged into the environment. In this paper arguments are presented that suggest, that there is a far more serious cause for global warming that will manifest itself in the next two or three centuries; direct heating from the exponential growth of energy usage by humankind. Because this is a minor contributor to the global warming problem at present, it is overlooked or ignored. Energy use from the combustion of fuels and from the output of nuclear reactions eventually is manifest as warming of the surroundings. Thus, as energy is used at an ever increasing rate the consequent global warming also increases at an ever increasing rate. Eventually this rate will become equal to a few percent of solar radiation. When this happens the earth's temperature will have risen by several degrees with catastrophic results. The trends in world energy use are reviewed and some mathematical models are presented to suggest future scenarios. These models can be used to predict when the global warming problem will become undeniably apparent, when it will become critical, and when it will become catastrophic

  18. Causes of the large warm bias in the Angola-Benguela Frontal Zone in the Norwegian Earth System Model

    Science.gov (United States)

    Koseki, Shunya; Keenlyside, Noel; Demissie, Teferi; Toniazzo, Thomas; Counillon, Francois; Bethke, Ingo; Ilicak, Mehmet; Shen, Mao-Lin

    2017-09-01

    We have investigated the causes of the sea surface temperature (SST) bias in the Angola-Benguela Frontal Zone (ABFZ) of the southeastern Atlantic Ocean simulated by the Norwegian Earth System Model (NorESM). Similar to other coupled-models, NorESM has a warm SST bias in the ABFZ of up to 8 °C in the annual mean. Our analysis of NorESM reveals that a cyclonic surface wind bias over the ABFZ drives a locally excessively strong southward (0.05 m/s (relative to observation)) Angola Current displacing the ABFZ southward. A series of uncoupled stand-alone atmosphere and ocean model simulations are performed to investigate the cause of the coupled model bias. The stand-alone atmosphere model driven with observed SST exhibits a similar cyclonic surface circulation bias; while the stand-alone ocean model forced with the reanalysis data produces a warm SST in the ABFZ with a magnitude approximately half of that in the coupled NorESM simulation. An additional uncoupled sensitivity experiment shows that the atmospheric model's local negative surface wind curl generates anomalously strong Angola Current at the ocean surface. Consequently, this contributes to the warm SST bias in the ABFZ by 2 °C (compared to the reanalysis forced simulation). There is no evidence that local air-sea feedbacks among wind stress curl, SST, and sea level pressure (SLP) affect the ABFZ SST bias. Turbulent surface heat flux differences between coupled and uncoupled experiments explain the remaining 2 °C warm SST bias in NorESM. Ocean circulation, upwelling and turbulent heat flux errors all modulate the intensity and the seasonality of the ABFZ errors.

  19. The "Family Tree" of Air Distribution Systems

    DEFF Research Database (Denmark)

    Nielsen, Peter V.

    2011-01-01

    that all the known types of air distribution systems are interconnected in a “family tree”. The influence of supplied momentum flow versus buoyancy forces is discussed, and geometries for high ventilation effectiveness are indicated as well as geometries for fully mixed flow. The paper will also show...... conditions which are not used for air distribution in general. A number of experiments with different air distribution systems are addressed, and they illustrate the behaviour at the different conditions discussed in the paper.......In this paper all total volume air distribution principles are addressed based on discussions of air flow pattern in a room with heat sources giving a cooling load. The supply and exhaust air openings are considered to have different locations and sizes in the room, and it is possible to show...

  20. The Air Program Information Management System (APIMS)

    Science.gov (United States)

    2011-11-02

    Technology November 2, 2011 The Air Program Information Management System (APIMS) Frank Castaneda, III, P.E. APIMS Program Manager AFCEE/TDNQ APIMS...NOV 2011 2. REPORT TYPE 3. DATES COVERED 00-00-2011 to 00-00-2011 4. TITLE AND SUBTITLE The Air Program Information Management System (APIMS... Information   Management   System : Sustainability of  Enterprise air quality management system • Aspects and Impacts to Process • Auditing and Measurement

  1. Contributions of surface solar radiation and precipitation to the spatiotemporal patterns of surface and air warming in China from 1960 to 2003

    Science.gov (United States)

    Du, Jizeng; Wang, Kaicun; Wang, Jiankai; Ma, Qian

    2017-04-01

    Although global warming has been attributed to increases in atmospheric greenhouses gases, the mechanisms underlying spatiotemporal patterns of warming trends remain under debate. Herein, we analyzed surface and air warming observations recorded at 1977 stations in China from 1960 to 2003. Our results showed a significant spatial pattern for the warming of the daily maximum surface (Ts-max) and air (Ta-max) temperatures, and the pattern was stronger in northwest and northeast China and weaker or negative in South China and the North China Plain. These warming spatial patterns were attributed to surface shortwave solar radiation (Rs) and precipitation (P), which play a key role in the surface energy budget. During the study period, Rs decreased by -1.50 ± 0.42 W m-2 10 yr-1 in China, which reduced the trends of Ts-max and Ta-max by about 0.139 and 0.053 °C 10 yr-1, respectively. More importantly, the decreasing rates in South China and the North China Plain were stronger than those in other parts of China. The spatial contrasts in the trends of Ts-max and Ta-max in China were significantly reduced after adjusting for the effect of Rs and P. For example, after adjusting for the effect of Rs and P, the difference in the Ts-max and Ta-max values between the North China Plain and the Loess Plateau was reduced by 97.8 and 68.3 %, respectively; the seasonal contrast in Ts-max and Ta-max decreased by 45.0 and 17.2 %, respectively; and the daily contrast in the warming rates of the surface and air temperature decreased by 33.0 and 29.1 %, respectively. This study shows that the land energy budget plays an essential role in the identification of regional warming patterns.

  2. Contributions of Surface Solar Radiation and Precipitation to the Spatiotemporal Patterns of Surface and Air Warming in China from 1960 to 2003

    Science.gov (United States)

    Jizeng, D.; Wang, K.; Wang, J.; Ma, Q.

    2017-12-01

    Although global warming has been attributed to increases in atmospheric greenhouses gases, the mechanisms underlying spatiotemporal patterns of warming trends remain under debate. Herein, we analyzed surface and air warming observations recorded at 1,977 stations in China from 1960 to 2003. Our results showed a significant spatial pattern for the warming of the daily maximum surface (Ts-max) and air (Ta-max) temperatures, and the pattern was stronger in northwest and northeast China and weaker or negative in South China and the North China Plain. These warming spatial patterns were attributed to surface shortwave solar radiation (Rs) and precipitation (P), which play a key role in the surface energy budget. During the study period, Rs decreased by -1.50±0.42 W m-2 10yr-1 in China, which reduced the trends of Ts-max and Ta-max by about 0.139 and 0.053 °C 10yr-1, respectively. More importantly, the decreasing rates in South China and the North China Plain were stronger than those in other parts of China. The spatial contrasts in the trends of Ts-max and Ta-max in China were significantly reduced after adjusting for the effect of Rs and P. For example, after adjusting for the effect of Rs and P, the difference in the Ts-max and Ta-max values between the North China Plain and the Loess Plateau was reduced by 97.8% and 68.3%, respectively, the seasonal contrast in Ts-max and Ta-max decreased by 45.0% and 17.2%, respectively, and the daily contrast in the warming rates of the surface and air temperature decreased by 33.0% and 29.1%, respectively. This study shows that the land energy budget plays an essential role in the identification of regional warming patterns.

  3. Functioning of a Shallow-Water Sediment System during Experimental Warming and Nutrient Enrichment

    Science.gov (United States)

    Alsterberg, Christian; Sundbäck, Kristina; Hulth, Stefan

    2012-01-01

    Effects of warming and nutrient enrichment on intact unvegetated shallow-water sediment were investigated for 5 weeks in the autumn under simulated natural field conditions, with a main focus on trophic state and benthic nitrogen cycling. In a flow-through system, sediment was exposed to either seawater at ambient temperature or seawater heated 4°C above ambient, with either natural or nutrient enriched water. Sediment–water fluxes of oxygen and inorganic nutrients, nitrogen mineralization, and denitrification were measured. Warming resulted in an earlier shift to net heterotrophy due to increased community respiration; primary production was not affected by temperature but (slightly) by nutrient enrichment. The heterotrophic state was, however, not further strengthened by warming, but was rather weakened, probably because increased mineralization induced a shortage of labile organic matter. Climate-related warming of seawater during autumn could therefore, in contrast to previous predictions, induce shorter but more intensive heterotrophic periods in shallow-water sediments, followed by longer autotrophic periods. Increased nitrogen mineralization and subsequent effluxes of ammonium during warming suggested a preferential response of organisms driving nitrogen mineralization when compared to sinks of ammonium such as nitrification and algal assimilation. Warming and nutrient enrichment resulted in non-additive effects on nitrogen mineralization and denitrification (synergism), as well as on benthic fluxes of phosphate (antagonism). The mode of interaction appears to be related to the trophic level of the organisms that are the main drivers of the affected processes. Despite the weak response of benthic microalgae to both warming and nutrient enrichment, the assimilation of nitrogen by microalgae was similar in magnitude to rates of nitrogen mineralization. This implies a sustained filter function and retention capacity of nutrients by the sediment. PMID

  4. Laser system detects air turbulence

    Science.gov (United States)

    Dahm, W. K.; Dunkin, J. A.; Weaver, E. A.

    1973-01-01

    Laser beam is emitted from pod on side of aircraft. Some scattered light returns to aircraft, but at shifted frequency caused by Doppler effect from local air speeds. Current work focuses on extending range, including investigations of effects of particle density, focusing, back scatter efficiency, absorption, and other factors.

  5. AEROMETRIC INFORMATION RETRIEVAL SYSTEM (AIRS) - GRAPHICS

    Science.gov (United States)

    Aerometric Information Retrieval System (AIRS) is a computer-based repository of information about airborne pollution in the United States and various World Health Organization (WHO) member countries. AIRS is administered by the U.S. Environmental Protection Agency, and runs on t...

  6. Air Quality Monitoring System and Benchmarking

    DEFF Research Database (Denmark)

    Liu, Xiufeng; Nielsen, Per Sieverts

    2017-01-01

    Air quality monitoring has become an integral part of smart city solutions. This paper presents an air quality monitoring system based on Internet of Things (IoT) technologies, and establishes a cloud-based platform to address the challenges related to IoT data management and processing...

  7. Solar-powered hot-air system

    Science.gov (United States)

    1979-01-01

    Solar-powered air heater supplies part or all of space heating requirements of residential or commercial buildings and is interfaced with air to water heat exchanger to heat domestic hot water. System has potential application in drying agricultural products such as cotton, lumber, corn, grains, and peanuts.

  8. On the warm nearshore bias in Pathfinder monthly SST products over Eastern Boundary upwelling systems

    CSIR Research Space (South Africa)

    Dufois, F

    2012-01-01

    Full Text Available Using in situ sea surface temperature (SST) data and MODIS/TERRA SST, the monthly AVHRR Pathfinder (version 5.0 and 5.2) SST product was evaluated within the four main Eastern Boundary Upwelling Systems. A warm bias in the monthly Pathfinder data...

  9. An Air Bearing Rotating Coil Magnetic Measurement System

    CERN Document Server

    Gottschalk, Stephen C; Taylor, David J; Thayer, William

    2005-01-01

    This paper describes a rotating coil magnetic measurement system supported on air bearings. The design is optimized for measurements of 0.1micron magnetic centerline changes on long, small aperture quadrupoles. Graphite impregnated epoxy resin is used for the coil holder and coil winding forms. Coil holder diameter is 11 mm with a length between supports of 750mm. A pair of coils is used to permit quadrupole bucking during centerline measurements. Coil length is 616mm, inner radius 1.82mm, outer radius 4.74mm. The key features of the mechanical system are simplicity; air bearings for accurate, repeatable measurements without needing warm up time and a vibration isolated stand that uses a steel-topped Newport optical table with air suspension. Coil rotation is achieved by a low noise servo motor controlled by a standalone Ethernet servo board running custom servo software. Coil calibration procedures that correct wire placement errors, tests for mechanical resonances, and other system checks will also be discu...

  10. Can Elevated Air [CO2] Conditions Mitigate the Predicted Warming Impact on the Quality of Coffee Bean?

    Directory of Open Access Journals (Sweden)

    José C. Ramalho

    2018-03-01

    Full Text Available Climate changes, mostly related to high temperature, are predicted to have major negative impacts on coffee crop yield and bean quality. Recent studies revealed that elevated air [CO2] mitigates the impact of heat on leaf physiology. However, the extent of the interaction between elevated air [CO2] and heat on coffee bean quality was never addressed. In this study, the single and combined impacts of enhanced [CO2] and temperature in beans of Coffea arabica cv. Icatu were evaluated. Plants were grown at 380 or 700 μL CO2 L-1 air, and then submitted to a gradual temperature rise from 25°C up to 40°C during ca. 4 months. Fruits were harvested at 25°C, and in the ranges of 30–35 or 36–40°C, and bean physical and chemical attributes with potential implications on quality were then examined. These included: color, phenolic content, soluble solids, chlorogenic, caffeic and p-coumaric acids, caffeine, trigonelline, lipids, and minerals. Most of these parameters were mainly affected by temperature (although without a strong negative impact on bean quality, and only marginally, if at all, by elevated [CO2]. However, the [CO2] vs. temperature interaction strongly attenuated some of the negative impacts promoted by heat (e.g., total chlorogenic acids, thus maintaining the bean characteristics closer to those obtained under adequate temperature conditions (e.g., soluble solids, caffeic and p-coumaric acids, trigonelline, chroma, Hue angle, and color index, and increasing desirable features (acidity. Fatty acid and mineral pools remained quite stable, with only few modifications due to elevated air [CO2] (e.g., phosphorous and/or heat. In conclusion, exposure to high temperature in the last stages of fruit maturation did not strongly depreciate bean quality, under the conditions of unrestricted water supply and moderate irradiance. Furthermore, the superimposition of elevated air [CO2] contributed to preserve bean quality by modifying and mitigating

  11. Can Elevated Air [CO2] Conditions Mitigate the Predicted Warming Impact on the Quality of Coffee Bean?

    Science.gov (United States)

    Ramalho, José C; Pais, Isabel P; Leitão, António E; Guerra, Mauro; Reboredo, Fernando H; Máguas, Cristina M; Carvalho, Maria L; Scotti-Campos, Paula; Ribeiro-Barros, Ana I; Lidon, Fernando J C; DaMatta, Fábio M

    2018-01-01

    Climate changes, mostly related to high temperature, are predicted to have major negative impacts on coffee crop yield and bean quality. Recent studies revealed that elevated air [CO 2 ] mitigates the impact of heat on leaf physiology. However, the extent of the interaction between elevated air [CO 2 ] and heat on coffee bean quality was never addressed. In this study, the single and combined impacts of enhanced [CO 2 ] and temperature in beans of Coffea arabica cv. Icatu were evaluated. Plants were grown at 380 or 700 μL CO 2 L -1 air, and then submitted to a gradual temperature rise from 25°C up to 40°C during ca. 4 months. Fruits were harvested at 25°C, and in the ranges of 30-35 or 36-40°C, and bean physical and chemical attributes with potential implications on quality were then examined. These included: color, phenolic content, soluble solids, chlorogenic, caffeic and p -coumaric acids, caffeine, trigonelline, lipids, and minerals. Most of these parameters were mainly affected by temperature (although without a strong negative impact on bean quality), and only marginally, if at all, by elevated [CO 2 ]. However, the [CO 2 ] vs. temperature interaction strongly attenuated some of the negative impacts promoted by heat (e.g., total chlorogenic acids), thus maintaining the bean characteristics closer to those obtained under adequate temperature conditions (e.g., soluble solids, caffeic and p -coumaric acids, trigonelline, chroma, Hue angle, and color index), and increasing desirable features (acidity). Fatty acid and mineral pools remained quite stable, with only few modifications due to elevated air [CO 2 ] (e.g., phosphorous) and/or heat. In conclusion, exposure to high temperature in the last stages of fruit maturation did not strongly depreciate bean quality, under the conditions of unrestricted water supply and moderate irradiance. Furthermore, the superimposition of elevated air [CO 2 ] contributed to preserve bean quality by modifying and mitigating

  12. Particulate matter air pollution in Europe in a +2 °C warming world

    Science.gov (United States)

    Lacressonnière, Gwendoline; Watson, Laura; Gauss, Michael; Engardt, Magnuz; Andersson, Camilla; Beekmann, Matthias; Colette, Augustin; Foret, Gilles; Josse, Béatrice; Marécal, Virginie; Nyiri, Agnes; Siour, Guillaume; Sobolowski, Stefan; Vautard, Robert

    2017-04-01

    In the framework of the IMPACT2C project, we have evaluated the future European particulate matter concentrations under the influence of climate change and anthropogenic emission reductions. To do so, 30-year simulations for present and future scenarios were performed with an ensemble of four regional Chemical Transport Models. +2 °C scenarios were issued from different regional climate simulations belonging to the CORDEX experiment (RCP4.5 scenario). Comparing present day simulations to observations shows that these simulations meet the requested quality criteria even if some biases do exist. Also, we showed that using regional climate models instead of meteorological reanalysis was not critical for the quality of our simulations. Present day as well as future scenarios show the large variability between models associated with different meteorology and process parameterizations. Future projections of PM concentrations show a large reduction of PM10 and PM2.5 concentrations in a +2 °C climate over the European continent (especially over Benelux), which can be mostly attributed to emission reduction policies. Under a current legislation scenario, annual PM10 could be reduced by between 1.8 and 2.9 μg m-3 (14.1-20.4%). If maximum technologically feasible emission reductions were implemented, further reductions of 1.4-1.9 μg m-3 (18.6-20.9%) are highlighted. Changes due to a +2 °C warming, in isolation from emission changes, are in general much weaker (-1.1 to +0.4 μg m-3,-0.3 to +5.1% for annual PM10 averaged over the European domain). Even if large differences exist between models, we have determined that the decrease of PM over Europe associated with emission reduction is a robust result. The patterns of PM changes resulting from climate change (for example the increase of PM over Spain and southern France and the decrease of PM10 over eastern Europe) are also robustly predicted even if its amplitude remains weak compared to changes associated with emission

  13. The effects of air leaks on solar air heating systems

    Science.gov (United States)

    Elkin, R.; Cash, M.

    1979-01-01

    This paper presents the results of an investigation to determine the effects of leakages in collector and duct work on the system performance of a typical single-family residence solar air heating system. Positive (leakage out) and negative (leakage in) pressure systems were examined. Collector and duct leakage rates were varied from 10 to 30 percent of the system flow rate. Within the range of leakage rates investigated, solar contribution to heated space and domestic hot water loads was found to be reduced up to 30 percent from the no-leak system contribution with duct leakage equally divided between supply and return duct; with supply duct leakage greater than return leakage a reduction of up to 35 percent was noted. The negative pressure system exhibited a reduction in solar contribution somewhat larger than the positive pressure system for the same leakage rates.

  14. Effects of Thermal Mass, Window Size, and Night-Time Ventilation on Peak Indoor Air Temperature in the Warm-Humid Climate of Ghana

    Directory of Open Access Journals (Sweden)

    S. Amos-Abanyie

    2013-01-01

    Full Text Available Most office buildings in the warm-humid sub-Saharan countries experience high cooling load because of the predominant use of sandcrete blocks which are of low thermal mass in construction and extensive use of glazing. Relatively, low night-time temperatures are not harnessed in cooling buildings because office openings remain closed after work hours. An optimization was performed through a sensitivity analysis-based simulation, using the Energy Plus (E+ simulation software to assess the effects of thermal mass, window size, and night ventilation on peak indoor air temperature (PIAT. An experimental system was designed based on the features of the most promising simulation model, constructed and monitored, and the experimental data used to validate the simulation model. The results show that an optimization of thermal mass and window size coupled with activation of night-time ventilation provides a synergistic effect to obtain reduced peak indoor air temperature. An expression that predicts, indoor maximum temperature has been derived for models of various thermal masses.

  15. Plasma Air Decontamination System (PADS), Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric-pressure plasma technology. Compared to...

  16. Plasma Air Decontamination System (PADS), Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed Plasma Air Decontamination System (PADS) is a trace contaminant control device based on non-thermal atmospheric pressure plasma technology that operates...

  17. Air quality and future energy system planning

    Science.gov (United States)

    Sobral Mourao, Zenaida; Konadu, Dennis; Lupton, Rick

    2016-04-01

    Ambient air pollution has been linked to an increasing number of premature deaths throughout the world. Projected increases in demand for food, energy resources and manufactured products will likely contribute to exacerbate air pollution with an increasing impact on human health, agricultural productivity and climate change. Current events such as tampering emissions tests by VW car manufacturers, failure to comply with EU Air Quality directives and WHO guidelines by many EU countries, the problem of smog in Chinese cities and new industrial emissions regulations represent unique challenges but also opportunities for regulators, local authorities and industry. However current models and practices of energy and resource use do not consider ambient air impacts as an integral part of the planing process. Furthermore the analysis of drivers, sources and impacts of air pollution is often fragmented, difficult to understand and lacks effective visualization tools that bring all of these components together. This work aims to develop a model that links impacts of air quality on human health and ecosystems to current and future developments in the energy system, industrial and agricultural activity and patterns of land use. The model will be added to the ForeseerTM tool, which is an integrated resource analysis platform that has been developed at the University of Cambridge initially with funding from BP and more recently through the EPSRC funded Whole Systems Energy Modeling (WholeSEM) project. The basis of the tool is a set of linked physical models for energy, water and land, including the technologies that are used to transform these resources into final services such as housing, food, transport and household goods. The new air quality model will explore different feedback effects between energy, land and atmospheric systems with the overarching goal of supporting better communication about the drivers of air quality and to incorporate concerns about air quality into

  18. Amplification of global warming through pH dependence of DMS production simulated with a fully coupled Earth system model

    Science.gov (United States)

    Schwinger, Jörg; Tjiputra, Jerry; Goris, Nadine; Six, Katharina D.; Kirkevåg, Alf; Seland, Øyvind; Heinze, Christoph; Ilyina, Tatiana

    2017-08-01

    We estimate the additional transient surface warming ΔTs caused by a potential reduction of marine dimethyl sulfide (DMS) production due to ocean acidification under the high-emission scenario RCP8.5 until the year 2200. Since we use a fully coupled Earth system model, our results include a range of feedbacks, such as the response of marine DMS production to the additional changes in temperature and sea ice cover. Our results are broadly consistent with the findings of a previous study that employed an offline model set-up. Assuming a medium (strong) sensitivity of DMS production to pH, we find an additional transient global warming of 0.30 K (0.47 K) towards the end of the 22nd century when DMS emissions are reduced by 7.3 Tg S yr-1 or 31 % (11.5 Tg S yr-1 or 48 %). The main mechanism behind the additional warming is a reduction of cloud albedo, but a change in shortwave radiative fluxes under clear-sky conditions due to reduced sulfate aerosol load also contributes significantly. We find an approximately linear relationship between reduction of DMS emissions and changes in top of the atmosphere radiative fluxes as well as changes in surface temperature for the range of DMS emissions considered here. For example, global average Ts changes by -0. 041 K per 1 Tg S yr-1 change in sea-air DMS fluxes. The additional warming in our model has a pronounced asymmetry between northern and southern high latitudes. It is largest over the Antarctic continent, where the additional temperature increase of 0.56 K (0.89 K) is almost twice the global average. We find that feedbacks are small on the global scale due to opposing regional contributions. The most pronounced feedback is found for the Southern Ocean, where we estimate that the additional climate change enhances sea-air DMS fluxes by about 9 % (15 %), which counteracts the reduction due to ocean acidification.

  19. Amplification of global warming through pH dependence of DMS production simulated with a fully coupled Earth system model

    Directory of Open Access Journals (Sweden)

    J. Schwinger

    2017-08-01

    Full Text Available We estimate the additional transient surface warming ΔTs caused by a potential reduction of marine dimethyl sulfide (DMS production due to ocean acidification under the high-emission scenario RCP8.5 until the year 2200. Since we use a fully coupled Earth system model, our results include a range of feedbacks, such as the response of marine DMS production to the additional changes in temperature and sea ice cover. Our results are broadly consistent with the findings of a previous study that employed an offline model set-up. Assuming a medium (strong sensitivity of DMS production to pH, we find an additional transient global warming of 0.30 K (0.47 K towards the end of the 22nd century when DMS emissions are reduced by 7.3 Tg S yr−1 or 31 % (11.5 Tg S yr−1 or 48 %. The main mechanism behind the additional warming is a reduction of cloud albedo, but a change in shortwave radiative fluxes under clear-sky conditions due to reduced sulfate aerosol load also contributes significantly. We find an approximately linear relationship between reduction of DMS emissions and changes in top of the atmosphere radiative fluxes as well as changes in surface temperature for the range of DMS emissions considered here. For example, global average Ts changes by −0. 041 K per 1 Tg S yr−1 change in sea–air DMS fluxes. The additional warming in our model has a pronounced asymmetry between northern and southern high latitudes. It is largest over the Antarctic continent, where the additional temperature increase of 0.56 K (0.89 K is almost twice the global average. We find that feedbacks are small on the global scale due to opposing regional contributions. The most pronounced feedback is found for the Southern Ocean, where we estimate that the additional climate change enhances sea–air DMS fluxes by about 9 % (15 %, which counteracts the reduction due to ocean acidification.

  20. Prototype Hybrid Systems for Neonatal Warming: In Vitro Comparisons to Standard of Care Devices

    Science.gov (United States)

    Hubert, Terrence L.; Lindemann, Rolf; Wu, Jichuan; Agnew, Catherine; Shaffer, Thomas H.; Wolfson, Marla R.

    2013-01-01

    Preterm infants lack necessary thermoregulation. An ideal incubator should maintain a uniform and constant thermal environment. We compared the effectiveness of a supplemental heating blanket to improve the heating characteristics of two different incubator warming devices using assessment of their respective function alone as controls. Device A and device B, with and without a heating blanket (Harvard Apparatus), were instrumented with a distribution matrix of multiple temperature (n = 11) and humidity probes. These data were serially measured during warm up to 37.5 °C and through a series of open-door perturbations. The time constant, temperature variation, and change in air temperature were calculated. Data were analyzed for significance by 2-factor ANOVA for each respective incubator either turned on or off with either the heating blanket turned on or off. Device A warms faster (33.87% ; p < 0.05) than device B, but has a greater (37.27% ; p < 0.05) temperature variation during warmup. The heating blanket enhances the thermal response of device A during warmup, but does not alter those of device B. With the side door open, device A shows a smaller (−16.5% ; p < 0.05) temperature variation than device B; the heating blanket attenuates the temperature change in both devices. These results demonstrate that the use of a supplemental heating blanket, as well as device-related differences, may impact clinical control of a thermal environment. PMID:21142524

  1. Automatic control system of brain temperature by air-surface cooling for therapeutic hypothermia.

    Science.gov (United States)

    Utsuki, T

    2013-01-01

    An automatic control system of brain temperature by air-surface cooling was developed for therapeutic hypothermia, which is increasingly recommended for hypoxic-ischemic encephalopathy after cardiac arrest and neonatal asphyxia in several guidelines pertinent to resuscitation. Currently, water-surface cooling is the most widespread cooling method in therapeutic hypothermia. However, it requires large electric power for precise control and also needs water-cooling blankets which have potential for compression of patients by its own weight and for water leakage in ICU. Air-surface cooling does not have such problems and is more suitable for clinical use than water-surface cooling, because air has lower specific heat and density as well as the impossibility of the contamination in ICU by its leakage. In the present system, brain temperature of patients is automatically controlled by suitable adjustment of the temperature of the air blowing into the cooling blankets. This adjustment is carried out by the regulation of mixing cool and warm air using proportional control valves. The computer in the developed control apparatus suitably calculates the air temperature and rotation angle of the valves every sampling time on the basis of the optimal-adaptive control algorithm. Thus, the proposed system actualizes automatic control of brain temperature by the inputting only the clinically desired temperature of brain. The control performance of the suggested system was verified by the examination using the mannequin in substitution for an adult patient. In the result, the control error of the head temperature of the mannequin was 0.12 °C on average in spite of the lack of the production capacity of warm air after the re-warming period. Thus, this system serves as a model for the clinically applied system.

  2. Airport Information Retrieval System (AIRS) System Support Manual

    Science.gov (United States)

    1973-01-01

    This handbook is a support manual for prototype air traffic flow control automation system developed for the FAA's Systems Command Center. The system is implemented on a time-sharing computer and is designed to provide airport traffic load prediction...

  3. Airport Information Retrieval System (AIRS) User's Guide

    Science.gov (United States)

    1973-08-01

    The handbook is a user's guide for a prototype air traffic flow control automation system developed for the FAA's System Command Center. The system is implemented on a time-sharing computer and is designed to provide airport traffic load predictions ...

  4. Converting Constant Volume, Multizone Air Handling Systems to Energy Efficient Variable Air Volume Multizone Systems

    Science.gov (United States)

    2017-10-26

    air volume. This will also reduce greenhouse gas production, although the extent depends on the fuels used to generate electricity and heating and...multizone system to a variable air volume system ordinarily requires re- ducting and re-zoning to accommodate “VAV box” terminal units and is a major...deck with associated heating and cooling coils. The system fan operates at a constant speed, and zone dampers blend the hot and cold air from these

  5. Dry and mixed air cooling systems

    International Nuclear Information System (INIS)

    Gutner, Gidali.

    1975-01-01

    The various dry air cooling systems now in use or being developed are classified. The main dimensioning parameters are specified and the main systems already built are given with their characteristics. The available data allow dry air cooling to be situated against the other cooling modes and so specify the aim of the research or currently developed works. Some systems at development stages are briefly described. The interest in mixed cooling (assisted draft) and the principal available systems is analyzed. A program of research is outlined [fr

  6. Preliminary design package for residential heating/cooling system: Rankine air conditioner redesign

    Science.gov (United States)

    1978-01-01

    A summary of the preliminary redesign and development of a marketable single family heating and cooling system is presented. The interim design and schedule status of the residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities were discussed. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

  7. Preliminary design package for residential heating/cooling system--Rankine air conditioner redesign

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-01

    This report contains a summary of the preliminary redesign and development of a marketable single-family heating and cooling system. The objectives discussed are the interim design and schedule status of the Residential (3-ton) redesign, problem areas and solutions, and the definition of plans for future design and development activities. The proposed system for a single-family residential heating and cooling system is a single-loop, solar-assisted, hydronic-to-warm-air heating subsystem with solar-assisted domestic water heating and a Rankine-driven expansion air-conditioning subsystem.

  8. Citizen science shows systematic changes in the temperature difference between air and inland waters with global warming.

    Science.gov (United States)

    Weyhenmeyer, Gesa A; Mackay, Murray; Stockwell, Jason D; Thiery, Wim; Grossart, Hans-Peter; Augusto-Silva, Pétala B; Baulch, Helen M; de Eyto, Elvira; Hejzlar, Josef; Kangur, Külli; Kirillin, Georgiy; Pierson, Don C; Rusak, James A; Sadro, Steven; Woolway, R Iestyn

    2017-03-06

    Citizen science projects have a long history in ecological studies. The research usefulness of such projects is dependent on applying simple and standardized methods. Here, we conducted a citizen science project that involved more than 3500 Swedish high school students to examine the temperature difference between surface water and the overlying air (T w -T a ) as a proxy for sensible heat flux (Q H ). If Q H is directed upward, corresponding to positive T w -T a , it can enhance CO 2 and CH 4 emissions from inland waters, thereby contributing to increased greenhouse gas concentrations in the atmosphere. The students found mostly negative T w -T a across small ponds, lakes, streams/rivers and the sea shore (i.e. downward Q H ), with T w -T a becoming increasingly negative with increasing T a . Further examination of T w -T a using high-frequency temperature data from inland waters across the globe confirmed that T w -T a is linearly related to T a . Using the longest available high-frequency temperature time series from Lake Erken, Sweden, we found a rapid increase in the occasions of negative T w -T a with increasing annual mean T a since 1989. From these results, we can expect that ongoing and projected global warming will result in increasingly negative T w -T a , thereby reducing CO 2 and CH 4 transfer velocities from inland waters into the atmosphere.

  9. Practical ways to abate air and water pollution worldwide including a unique way to significantly curb global warming

    Energy Technology Data Exchange (ETDEWEB)

    Snell, J.R.

    1998-07-01

    This paper points out that in the next 50 years it will largely be the developing countries of the world which will continue to industrialize rapidly and hence pollute the water and air of not only their countries but that this pollution is becoming global (80% of the World's population.) From the author's 25 years of consulting experience in the developing countries, their greatest need is to have available to them low cost, innovative processes for pollution abatement will be neglected and the whole world will suffer immensely. The paper discusses in some detail the type of innovative low cost methods which have successfully been used in the categories of wastewater and solid wastes and names 6 other categories where many others exist. All these innovative methods need to be discovered, listed, and tested for quality and dependability, and then made widely available. Large Environmental Engineering Universities and International Consulting Engineering firms need to be organized to undertake these important tasks. The paper also points out the connection between Global Warming and the Solid waste industry and shows how it can be controlled inexpensively by employing a new, unique, and rapid method of converting municipal refuse into methane and then using that to make electricity. Information given in this paper could lead to a vast reduction in future pollution, with the resulting better global health and at the same time save trillions of dollars.

  10. The Solutions Project: Educating the Public and Policy Makers About Solutions to Global Warming, Air Pollution, and Energy Security

    Science.gov (United States)

    Jacobson, M. Z.

    2015-12-01

    Three major global problems of our times are global warming, air pollution mortality and morbidity, and energy insecurity. Whereas, policy makers with the support of the public must implement solutions to these problems, it is scientists and engineers who are best equipped to evaluate technically sound, optimal, and efficient solutions. Yet, a disconnect exists between information provided by scientists and engineers and policies implemented. Part of the reason is that scientific information provided to policy makers and the public is swamped out by information provided by lobbyists and another part is the difficulty in providing information to the hundreds of millions of people who need it rather than to just a few thousand. What other ways are available, aside from issuing press releases on scientific papers, for scientists to disseminate information? Three growing methods are through social media, creative media, and storytelling. The Solutions Project is a non-profit non-governmental organization whose goal is to bring forth scientific information about 100% clean, renewable energy plans to the public, businesses, and policy makers using these and related tools. Through the use of social media, the development of engaging internet and video content, and storytelling, the group hopes to increase the dissemination of information for social good. This talk discusses the history and impacts to date of this group and its methods. Please see www.thesolutionsproject.org and 100.org for more information.

  11. 30 CFR 75.1730 - Compressed air; general; compressed air systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air; general; compressed air systems... Compressed air; general; compressed air systems. (a) All pressure vessels shall be constructed, installed... Safety and Health district office. (b) Compressors and compressed-air receivers shall be equipped with...

  12. Water regime and growth of young oak stands subjected to air-warming and drought on two different forest soils in a model ecosystem experiment.

    Science.gov (United States)

    Kuster, T M; Arend, M; Bleuler, P; Günthardt-Goerg, M S; Schulin, R

    2013-01-01

    Global climate change is expected to increase annual temperatures and decrease summer precipitation in Central Europe. Little is known of how forests respond to the interaction of these climate factors and if their responses depend on soil conditions. In a 3-year lysimeter experiment, we investigated the growth response of young mixed oak stands, on either acidic or calcareous soil, to soil water regime, air-warming and drought treatments corresponding to an intermediate climate change scenario. The air-warming and drought treatments were applied separately as well as in combination. The air-warming treatment had no effect on soil water availability, evapotranspiration or stand biomass. Decreased evapotranspiration from the drought-exposed stands led to significantly higher air and soil temperatures, which were attributed to impaired transpirational cooling. Water limitation significantly reduced the stand foliage, shoot and root biomass as droughts were severe, as shown in low leaf water potentials. Additional air warming did not enhance the drought effects on evapotranspiration and biomass, although more negative leaf water potentials were observed. After re-watering, evapotranspiration increased within a few days to pre-drought levels. Stands not subjected to the drought treatment produced significantly less biomass on the calcareous soil than on the acidic soil, probably due to P or Mn limitation. There was no difference in biomass and water regime between the two soils under drought conditions, indicating that nutrient availability was governed by water availability under these conditions. The results demonstrate that young oak stands can cope with severe drought and therefore can be considered for future forestry. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

  13. Testing of nuclear air-cleaning systems

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    A standard is presented which describes methods for field-testing nuclear power plant air cleaning systems. Included are specifications for visual inspection; duct and housing leak test; mounting frame pressure leak test; airflow capacity, distribution, and residence time tests; air-aerosol mixing uniformity test; in place leak test of HEPA filter banks; multiple sampling technique; in-place leak test of adsorber stage; laboratory testing of adsorbent; and duct heater performance test

  14. Advanced Overfire Air system and design

    Energy Technology Data Exchange (ETDEWEB)

    Gene berkau

    2004-07-30

    The objective of the proposed project is to design, install and optimize a prototype advanced tangential OFA air system on two mass feed stoker boilers that can burn coal, biomass and a mixture of these fuels. The results will be used to develop a generalized methodology for retrofit designs and optimization of advanced OFA air systems. The advanced OFA system will reduce particulate and NOx emissions and improve overall efficiency by reducing carbon in the ash and excess oxygen. The advanced OFA will also provide capabilities for carrying full load and improved load following and transitional operations.

  15. Assessment methodology for air defence control systems

    CSIR Research Space (South Africa)

    Oosthuizen, R

    2013-09-01

    Full Text Available is to defend own assets against air attack through optimisation of AD firepower as well as preventing fratricide or collateral damage. AD Control is a special case of the basic C2 process and system discussed above. The time pressure, execution risk...) and is used to ensure safe and effective defence of Vulnerable Points against air attack during operations. The AD Control system is in essence a Command and Control (C2) system that has to make sense of complex situations and manage the risks during...

  16. Operating experience feedback report - Air systems problems

    International Nuclear Information System (INIS)

    Ornstein, H.L.

    1987-12-01

    This report highlights significant operating events involving observed or potential failures of safety-related systems in U.S. plants that resulted from degraded or malfunctioning non-safety grade air systems. Based upon the evaluation of these events, the Office for Analysis and Evaluation of Operational Data (AEOD) concludes that the issue of air systems problems is an important one which requires additional NRC and industry attention. This report also provides AEOD's recommendations for corrective actions to deal with the issue. (author)

  17. Instrument air system - Aging impact on system availability

    International Nuclear Information System (INIS)

    Villaran, M.; Subudhi, M.

    1989-01-01

    As part of ongoing efforts to understand and manage the effects of aging in nuclear power plants, an aging assessment was performed for the Instrument Air (IA) system, a system that has been the subject of much scrutiny in recent years. Despite its non-safety classification, instrument air has been a factor in a number of potentially serious events. This report presents the results of the assessment and discusses the impact of instrument air system aging on system availability and plant safety. This work was performed for the US Nuclear Regulatory Commission (NRC) as part of the Nuclear Plant Aging Research (NPAR) program. To perform the complex task of analyzing an entire system, the Aging and Life Extension Assessment Program (ALEAP) System Level Plan was developed by Brookhaven National Laboratory and applied successfully in previous system aging studies. The work presented herein was performed using two parallel work paths, as described in the ALEAP plant. One path used deterministic techniques to assess the impact of aging on compressed air system performance, while the second path used probabilistic methods. Results from both paths then were used to characterize aging in the instrument air system. Some conclusions from this work are: compressors, air system valves, and air dryers were found to make up the majority of failures; the effectiveness and quantity of preventive maintenance devoted to a component significantly affected the amount of failures experienced; review of compressed air system designs and studies using a PRA-based system model revealed that the redundancy of key components (compressors, dryers, IA/SA crossconnect valve) was an important factor in system availability; total loss of air events are uncommon

  18. Safety-related control air systems - approved 1977

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    This standard applies to those portions of the control air system that furnish air required to support, control, or operate systems or portions of systems that are safety related in nuclear power plants. This standard relates only to the air supply system(s) for safety-related air operated devices and does not apply to the safety-related air operated device or to air operated actuators for such devices. The objectives of this standard are to provide (1) minimum system design requirements for equipment, piping, instruments, controls, and wiring that constitute the air supply system; and (2) the system and component testing and maintenance requirements

  19. Cold Vacuum Drying Instrument Air System Design Description. System 12

    International Nuclear Information System (INIS)

    SHAPLEY, B.J.; TRAN, Y.S.

    2000-01-01

    This system design description (SDD) addresses the instrument air (IA) system of the spent nuclear fuel (SNF). This IA system provides instrument quality air to the Cold Vacuum Drying (CVD) Facility. The IA system is a general service system that supports the operation of the heating, ventilation, and air conditioning (HVAC) system, the process equipment skids, and process instruments in the CVD Facility. The following discussion is limited to the compressor, dryer, piping, and valving that provide the IA as shown in Drawings H-1-82222, Cold Vacuum Drying Facility Mechanical Utilities Compressed and Instrument Air PandID, and H-1.82161, Cold Vacuum Drying Facility Process Equipment Skid PandID MCO/Cusk Interface. Figure 1-1 shows the physical location of the 1A system in the CVD Facility

  20. 49 CFR 570.57 - Air brake system and air-over-hydraulic brake subsystem.

    Science.gov (United States)

    2010-10-01

    ... meeting the following requirements: (1) With the vehicle in a stationary position, compressed air reserve... STANDARDS Vehicles With GVWR of More Than 10,000 Pounds § 570.57 Air brake system and air-over-hydraulic brake subsystem. The following requirements apply to vehicles with air brake and air-over-hydraulic...

  1. Plant air systems safety study: Portsmouth Gaseous Diffusion Plant

    International Nuclear Information System (INIS)

    1982-05-01

    The Portsmouth Gaseous Diffusion Plant Air System facilities and operations are reviewed for potential safety problems not covered by standard industrial safety procedures. Information is presented under the following section headings: facility and process description (general); air plant equipment; air distribution system; safety systems; accident analysis; plant air system safety overview; and conclusion

  2. Modeling aluminum-air battery systems

    Science.gov (United States)

    Savinell, R. F.; Willis, M. S.

    The performance of a complete aluminum-air battery system was studied with a flowsheet model built from unit models of each battery system component. A plug flow model for heat transfer was used to estimate the amount of heat transferred from the electrolyte to the air stream. The effect of shunt currents on battery performance was found to be insignificant. Using the flowsheet simulator to analyze a 100 cell battery system now under development demonstrated that load current, aluminate concentration, and electrolyte temperature are dominant variables controlling system performance. System efficiency was found to decrease as both load current and aluminate concentration increases. The flowsheet model illustrates the interdependence of separate units on overall system performance.

  3. Changes in the dynamics of foliar N metabolites in oak saplings by drought and air warming depend on species and soil type.

    Directory of Open Access Journals (Sweden)

    Bin Hu

    Full Text Available Climate change poses direct or indirect influences on physiological mechanisms in plants. In particular, long living plants like trees have to cope with the predicted climate changes (i.e. drought and air warming during their life span. The present study aimed to quantify the consequences of simulated climate change for foliar N metabolites over a drought-rewetting-drought course. Saplings of three Central European oak species (i.e. Quercus robur, Q. petraea, Q. pubescens were tested on two different soil types (i.e. acidic and calcareous. Consecutive drought periods increased foliar amino acid-N and soluble protein-N concentrations at the expense of structural N in all three oak species. In addition, transient effects on foliar metabolite dynamics were observed over the drought-rewetting-drought course. The lowest levels of foliar soluble protein-N, amino acid-N and potassium cation with a minor response to drought and air warming were found in the oak species originating from the driest/warmest habitat (Q. pubescens compared to Q. robur and Q. petraea. Higher foliar osmolyte-N and potassium under drought and air warming were observed in all oak species when grown on calcareous versus acidic soil. These results indicate that species-specific differences in physiological mechanisms to compensate drought and elevated temperature are modified by soil acidity.

  4. AIRMaster: Compressed air system audit software

    International Nuclear Information System (INIS)

    Wheeler, G.M.; Bessey, E.G.; McGill, R.D.; Vischer, K.

    1997-01-01

    The project goal was to develop a software tool, AIRMaster, and a methodology for performing compressed air system audits. AIRMaster and supporting manuals are designed for general auditors or plant personnel to evaluate compressed air system operation with simple instrumentation during a short-term audit. AIRMaster provides a systematic approach to compressed air system audits, analyzing collected data, and reporting results. AIRMaster focuses on inexpensive Operation and Maintenance (O and M) measures, such as fixing air leaks and improving controls that can significantly improve performance and reliability of the compressed air system, without significant risk to production. An experienced auditor can perform an audit, analyze collected data, and produce results in 2--3 days. AIRMaster reduces the cost of an audit, thus freeing funds to implement recommendations. The AIRMaster package includes an Audit Manual, Software and User's manual, Analysis Methodology Manual, and a Case Studies summary report. It also includes a Self-Guided Tour booklet to help users quickly screen a plant for efficiency improvement potentials, and an Industrial Compressed Air Systems Energy Efficiency Guidebook. AIRMaster proved to be a fast and effective audit tool. In sever audits AIRMaster identified energy savings of 4,056,000 kWh, or 49.2% of annual compressor energy use, for a cost savings of $152,000. Total implementation costs were $94,700 for a project payback period of 0.6 years. Available airflow increased between 11% and 51% of plant compressor capacity, leading to potential capital benefits from 40% to 230% of first year energy savings

  5. Mobile refrigeration system for precool and warm up of superconducting magnets

    Science.gov (United States)

    Gandla, S. K.; Longsworth, R. C.

    2017-12-01

    Conservation of helium has become more important in recent years due to global shortages in supply. Magnetic resonance imaging (MRI) superconducting magnets use approximately 20% of the world’s helium reserves in liquid form to cool down and maintain operating temperatures at 4 K. This paper describes a mobile cryogenic refrigeration system, which has been developed by Sumitomo (SHI) Cryogenics of America, Inc. to conserve helium by shipping MRI magnets warm and cooling them down or servicing them on site at a medical facility. The system can cool a typical magnet from room temperature to below 40K in less than a week. The system consists of four single stage Displex®-type Gifford-McMahon (GM) expanders in a cryostat with heat exchangers integrated on the cold ends that cool the helium gas, which is circulated in a closed-loop system through the magnet by a cryogenic fan. The system is configured with heaters on the heat exchangers to effectively warm up a magnet. The system includes a scroll vacuum pump, which is used to evacuate the helium circuit with or without the magnet and turbo pump to evacuate the cryostat. Vacuum-jacketed transfer lines connect the cryostat to the magnet. The system is designed with its own controller for continuous operation of precool, warm up and evacuation processes with automatic and manual controls. The cryostat, pumps and gas controls are mounted on a dewar cart. One compressor and the system controller are mounted on a compressor and control cart, and the other three compressors are mounted on separate carts.

  6. Combined air and water pollution control system

    Science.gov (United States)

    Wolverton, Billy C. (Inventor); Jarrell, Lamont (Inventor)

    1990-01-01

    A bioaquatic air pollution control system for controlling both water and atmospheric pollution is disclosed. The pollution control system includes an exhaust for directing polluted gases out of a furnace and a fluid circulating system which circulates fluid, such as waste water, from a source, past the furnace where the fluid flow entrains the pollutants from the furnace. The combined fluid and pollutants are then directed through a rock/plant/microbial filtering system. A suction pump pumps the treated waste water from the filter system past the exhaust to again entrain more pollutants from the furnace where they are combined with the fluid (waste water) and directed to the filter system.

  7. Thermal comfort and IAQ assessment of under-floor air distribution system integrated with personalized ventilation in hot and humid climate

    DEFF Research Database (Denmark)

    Li, Ruixin; Sekhar, S.C.; Melikov, Arsen Krikor

    2010-01-01

    The potential for improving occupants' thermal comfort with personalized ventilation (PV) system combined with under-floor air distribution (UFAD) system was explored through human response study. The hypothesis was that cold draught at feet can be reduced when relatively warm air is supplied...... by UFAD system and uncomfortable sensation as "warm head" can be reduced by the PV system providing cool and fresh outdoor air at the facial level. A study with 30 human subjects was conducted in a Field Environmental Chamber. The chamber was served by two dedicated systems a primary air handling unit...... of the results obtained reveal improved acceptability of perceived air quality and improved thermal sensation with PV-UFAD in comparison with the reference case of UFAD alone or mixing ventilation with ceiling supply diffuser. The local thermal sensation at the feet was also improved when warmer UFAD supply air...

  8. A mixed air/air and air/water heat pump system ensures the air-conditioning of a cinema; Un systeme mixte PAC air/air et air/eau climatise un cinema

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-03-01

    This article presents the air conditioning system of a new cinema complex of Boulogne (92, France) which comprises a double-flux air processing plant and two heat pumps. Each heat pump has two independent refrigerating loops: one with a air condenser and the other with a water condenser. This system allows to limit the power of the loop and to reduce the size of the cooling tower and of the vertical ducts. This article describes the technical characteristics of the installation: thermodynamic units, smoke clearing, temperature control, air renewing. (J.S.)

  9. A Novel Organic Rankine Cycle System with Improved Thermal Stability and Low Global Warming Fluids

    Directory of Open Access Journals (Sweden)

    Panesar Angad S

    2014-07-01

    Full Text Available This paper proposes a novel Organic Rankine Cycle (ORC system for long haul truck application. Rather than typical tail pipe heat recovery configurations, the proposed setup exploits the gaseous streams that are already a load on the engine cooling module. The system uses dual loops connected only by the Exhaust Gas Recirculation (EGR stream. A water blend study is conducted to identify suitable mixtures for the High Temperature (HT loop, while the Low Temperature (LT loop utilises a Low Global Warming (GWP Hydrofluoroether.

  10. 30 CFR 77.412 - Compressed air systems.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Compressed air systems. 77.412 Section 77.412... for Mechanical Equipment § 77.412 Compressed air systems. (a) Compressors and compressed-air receivers... involving the pressure system of compressors, receivers, or compressed-air-powered equipment shall not be...

  11. Reliability analysis of imperfect coverage systems with a shared warm standby

    Directory of Open Access Journals (Sweden)

    Li Pei-Chang

    2017-01-01

    Full Text Available Redundancy technique is commonly applied to satisfy the reliability requirements of fault-tolerant systems. Warm standby, a compromise between hot standby and cold standby in term of power consumption and recovery time, has attracted wide attention over the past several decades. However, the existing reliability analysis methods for warm standby system with imperfect coverage are difficult to deal with some cases, such as non-exponential time-to-failure distributions for the system components and the systems with shared standbys. In this paper, a new approach based on step function and impulse function is proposed to overcome the limitations of the existing approaches. The reliability of a system including shared standbys is deduced considering two kinds of imperfect fault coverage models, which contain Element Level Coverage (ELC and Fault Level Coverage (FLC. The proposed approach can applicable to any type of time-to-failure distributions for the system components subject to imperfect fault coverage. A case study is presented to illustrate the applications and advantages.

  12. Compressed-air flow control system.

    Science.gov (United States)

    Bong, Ki Wan; Chapin, Stephen C; Pregibon, Daniel C; Baah, David; Floyd-Smith, Tamara M; Doyle, Patrick S

    2011-02-21

    We present the construction and operation of a compressed-air driven flow system that can be used for a variety of microfluidic applications that require rapid dynamic response and precise control of multiple inlet streams. With the use of inexpensive and readily available parts, we describe how to assemble this versatile control system and further explore its utility in continuous- and pulsed-flow microfluidic procedures for the synthesis and analysis of microparticles.

  13. Systems Engineering Management Training at Naval Air Systems Command

    National Research Council Canada - National Science Library

    Rebel, James

    2000-01-01

    Within the past few years, the Naval Air Systems Command (NAVAIR) has undergone several major changes including an engineering reorganization from a matrix organization to an Integrated Program Team/Competency Aligned Organization (IPT/CAO...

  14. Developing a dynamic control system for mine compressed air networks

    OpenAIRE

    Van Heerden, S.W.; Pelzer, R.; Marais, J.H.

    2014-01-01

    Mines in general, make use of compressed air systems for daily operational activities. Compressed air on mines is traditionally distributed via compressed air ring networks where multiple shafts are supplied with compressed air from an integral system. These compressed air networks make use of a number of compressors feeding the ring from various locations in the network. While these mines have sophisticated control systems to control these compressors, they are not dynamic systems. Compresso...

  15. Saving energy by using underfloor-air-distribution (UFAD) system in commercial buildings

    Energy Technology Data Exchange (ETDEWEB)

    Alajmi, Ali [Department of Mechanical Engineering, College of Technological Studies, Public Authority of Applied Education and Training, P.O. Box 3831, Mishref 40189 (Kuwait); El-Amer, Wid [Mechanical Department Head in Option One International Office, P.O. Box 29667, Safat 13157 (Kuwait)

    2010-08-15

    The number of attempts by researchers to reduce building energy consumption has increased, ever since global warming became a serious issue. In this trend, a relatively new approach of air distribution, underfloor-air-distribution system (UFAD), has been widely used in new commercial buildings. This technique is simply accomplished by supplying air through a raised floor using different types of distribution configurations and outlets. In UFAD, the air is directly supplied to the occupants' area (occupied zone) causing occupants plumes and zone heat load stratify to the upper layer of the zone (unoccupied zone), which are later extracted from return points at high level. This flow pattern gives UFAD the advantage of using less energy than a conventional air-distribution system, ceiling-based air distribution (CBAD) due to lower pressure drop and lower air flow rate. This paper investigates the effectiveness of UFAD systems in commercial buildings for various types of application and at different air supply temperatures in a hot climate (The State of Kuwait). The findings show that UFAD has a significant saving of energy compared to CBAD ({proportional_to}30%); in particular with high ceiling building types, as well as providing satisfactory comfort conditions for the occupants. Ultimately, more investigations should be done on conventional building heights (offices) to optimize the utilization of thermal stratification at design and operation stages. (author)

  16. Saving energy by using underfloor-air-distribution (UFAD) system in commercial buildings

    International Nuclear Information System (INIS)

    Alajmi, Ali; El-Amer, Wid

    2010-01-01

    The number of attempts by researchers to reduce building energy consumption has increased, ever since global warming became a serious issue. In this trend, a relatively new approach of air distribution, underfloor-air-distribution system (UFAD), has been widely used in new commercial buildings. This technique is simply accomplished by supplying air through a raised floor using different types of distribution configurations and outlets. In UFAD, the air is directly supplied to the occupants' area (occupied zone) causing occupants plumes and zone heat load stratify to the upper layer of the zone (unoccupied zone), which are later extracted from return points at high level. This flow pattern gives UFAD the advantage of using less energy than a conventional air-distribution system, ceiling-based air distribution (CBAD) due to lower pressure drop and lower air flow rate. This paper investigates the effectiveness of UFAD systems in commercial buildings for various types of application and at different air supply temperatures in a hot climate (The State of Kuwait). The findings show that UFAD has a significant saving of energy compared to CBAD (∼30%); in particular with high ceiling building types, as well as providing satisfactory comfort conditions for the occupants. Ultimately, more investigations should be done on conventional building heights (offices) to optimize the utilization of thermal stratification at design and operation stages.

  17. Effects of free-air CO2 enrichment (FACE and soil warming on CH4 emission from a rice paddy field: impact assessment and stoichiometric evaluation

    Directory of Open Access Journals (Sweden)

    M. Okada

    2010-09-01

    Full Text Available Paddy fields are an important source of atmospheric CH4, the second most important greenhouse gas. There is a strong concern that the increasing atmospheric CO2 concentration ([CO2] and global warming are further stimulating CH4 emissions, but the magnitude of this stimulation varies substantially by study, and few open-field evaluations have been conducted. Here we report results obtained at a Japanese rice free-air CO2 enrichment (FACE site under water and soil temperature elevation during two growing seasons. Our objectives were to evaluate the effects of high [CO2] (ambient + 200 μmol mol−1 and elevated soil temperature (+ 2 °C on CH4 emissions under completely open-field conditions. We found about 80% enhancement in total seasonal emissions by the additive effects of FACE and warming, indicating a strong positive feedback effect of global warming. The enhancement in CH4 emission from the FACE-effect alone (+ 26% was statistically non-significant (P = 0.19. Nevertheless, observed positive correlations between CH4 emissions and rice biomass agreed well with previous studies, suggesting that higher photosynthesis led to greater rhizodeposition, which then acted as substrates for methanogenesis. Soil warming increased the emission by 44% (P < 0.001, which was equivalent to a Q10 of 5.5. Increased rice biomass by warming could only partly explain the enhanced CH4 emissions, but stoichiometric analysis of the electron budget indicated that even a moderate enhancement in organic matter decomposition due to soil warming can cause a large increase in CH4 production under conditions where Fe(III reduction, which was little affected by soil warming, dominates electron-accepting processes. At later rice growth stages, advanced root senescence due to elevated temperature probably provided more substrate for methanogenesis. Our stoichiometric evaluation showed that in situ Fe reduction characteristics and root turnover in response to elevated

  18. Assessment of commercially available energy-efficient room air conditioners including models with low global warming potential (GWP) refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Shah, N. K. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Park, W. Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gerke, B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-30

    Improving the energy efficiency of room air conditioners (RACs) while transitioning to low global-warming-potential (GWP) refrigerants will be a critical step toward reducing the energy, peak load, and emissions impacts of RACs while keeping costs low. Previous research quantified the benefits of leapfrogging to high efficiency in tandem with the transition to low-GWP refrigerants for RACs (Shah et al., 2015) and identified opportunities for initial action to coordinate energy efficiency with refrigerant transition in economies constituting about 65% of the global RAC market (Shah et al., 2017). This report describes further research performed to identify the best-performing (i.e., most efficient and low-GWP-refrigerant using) RACs on the market, to support an understanding of the best available technology (BAT). Understanding BAT can help support market-transformation programs for high-efficiency and low-GWP equipment such as minimum energy performance standards (MEPS), labeling, procurement, and incentive programs. We studied RACs available in six economies—China, Europe, India, Japan, South Korea, and the United States—that together account for about 70% of global RAC demand, as well as other emerging economies. The following are our key findings: • Highly efficient RACs using low-GWP refrigerants, e.g., HFC-32 (R-32) and HC-290 (R-290), are commercially available today at prices comparable to similar RACs using high-GWP HCFC-22 (R-22) or HFC-410A (R-410A). • High efficiency is typically a feature of high-end products. However, highly efficient, cost-competitive (less than 1,000 or 1,500 U.S. dollars in retail price, depending on size) RACs are available. • Where R-22 is being phased out, high GWP R-410A still dominates RAC sales in most mature markets except Japan, where R-32 dominates. • In all of the economies studied except Japan, only a few models are energy efficient and use low-GWP refrigerants. For example, in Europe, India, and Indonesia

  19. AIR GAP CONTROL SYSTEM FOR HYDROGENERATORS

    Directory of Open Access Journals (Sweden)

    I. O. Zaitsev

    2017-01-01

    Full Text Available In this paper, we report of the solving the actual problem of control the air gap in the hydrogenerators. The aim of the study was development of a computerized information-measuring system for measuring the air gap in the hydrogenator, which used two capacitive sensors with parallel coplanar electrodes, and the method of determining the shape of the envelope parameters hydrogenerator rotor poles relative to the center axis of rotation, using the measurement results of the air gap.In practical studies of the sensor circuit it has been shown that its use allows for the informative value of the sensor capacitance conversion function to obtain a high accuracy and resolution measurement with digital linearization of converting function of the sensor with use program utility. To determine the form deviations of the envelope line of the rotor pole from the ideal cylinder, which is one of the main structural defects of the technological errors as results the distortion of the shape of the air gap in the hydrogenator, when the machine was manufacture and assembly. It is proposed to describe the shape of the envelope to use a Fourier transform. Calculation of the coefficients of the Fourier series is performed using the method of least squares as the regression coefficients.Application of this method in processing the measuring data in a computerized information-measuring system the developed with the primary converter with coplanar parallel electrodes allowed attaining the high measurement accuracy and resolution informative in magnitude of the capacity.

  20. Heating, Ventilation and Air-Conditioning Systems, Part of Indoor Air Quality Design Tools for Schools

    Science.gov (United States)

    The main purposes of a Heating, Ventilation, and Air-Conditioning system are to help maintain good indoor air quality through adequate ventilation with filtration and provide thermal comfort. HVAC systems are among the largest energy consumers in schools.

  1. Community Multiscale Air Quality Modeling System (CMAQ)

    Science.gov (United States)

    CMAQ is a computational tool used for air quality management. It models air pollutants including ozone, particulate matter and other air toxics to help determine optimum air quality management scenarios.

  2. An Evaluation of the Environmental Impact of Different Commercial Supermarket Refrigeration Systems Using Low Global Warming Potential Refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Beshr, Mohamed [University of Maryland, College Park; Aute, Vikrant [University of Maryland, College Park; Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Radermacher, Reinhard [University of Maryland, College Park

    2014-01-01

    Commercial refrigeration systems consumed 1.21 Quads of primary energy in 2010 and are known to be a major source for refrigerant charge leakage into the environment. Thus, it is important to study the environmental impact of commercial supermarket refrigeration systems and improve their design to minimize any adverse impacts. The system s Life Cycle Climate Performance (LCCP) was presented as a comprehensive metric with the aim of calculating the equivalent mass of carbon dioxide released into the atmosphere throughout its lifetime, from construction to operation and destruction. In this paper, an open source tool for the evaluation of the LCCP of different air-conditioning and refrigeration systems is presented and used to compare the environmental impact of a typical multiplex direct expansion (DX) supermarket refrigeration systems based on three different refrigerants as follows: two hydrofluorocarbon (HFC) refrigerants (R-404A, and R-407F), and a low global warming potential (GWP) refrigerant (N-40). The comparison is performed in 8 US cities representing different climates. The hourly energy consumption of the refrigeration system, required for the calculation of the indirect emissions, is calculated using a widely used building energy modeling tool (EnergyPlus). A sensitivity analysis is performed to determine the impact of system charge and power plant emission factor on the LCCP results. Finally, we performed an uncertainty analysis to determine the uncertainty in total emissions for both R-404A and N-40 operated systems. We found that using low GWP refrigerants causes a considerable drop in the impact of uncertainty in the inputs related to direct emissions on the uncertainty of the total emissions of the system.

  3. New lubricant systems for cold and warm forging – advantages and limitations

    DEFF Research Database (Denmark)

    Bay, Niels

    2011-01-01

    The increasing focus on environmental issues and the requirements to establish solutions diminishing the impact on working environment as well as external environment has strongly motivated the efforts to develop new, environmentally friendly tribological systems for metal forming production....... The present paper gives an overview of these efforts substituting environmentally hazardous lubricants in cold, warm and hot forging by new, more harmless lubricants. Introduction of these new lubricants, however, has some drawbacks due to lower limits of lubrication leading to risk of pick-up, poor product...

  4. The 2014-2015 warming anomaly in the Southern California Current System observed by underwater gliders

    Science.gov (United States)

    Zaba, Katherine D.; Rudnick, Daniel L.

    2016-02-01

    Large-scale patterns of positive temperature anomalies persisted throughout the surface waters of the North Pacific Ocean during 2014-2015. In the Southern California Current System, measurements by our sustained network of underwater gliders reveal the coastal effects of the recent warming. Regional upper ocean temperature anomalies were greatest since the initiation of the glider network in 2006. Additional observed physical anomalies included a depressed thermocline, high stratification, and freshening; induced biological consequences included changes in the vertical distribution of chlorophyll fluorescence. Contemporaneous surface heat flux and wind strength perturbations suggest that local anomalous atmospheric forcing caused the unusual oceanic conditions.

  5. Analysis of warm water system as a protective layer on reactor for Serba Guna G.A. Siwabessy using computation fluid dynamics

    International Nuclear Information System (INIS)

    Tiar Fridianto; Tri Agung Rohmat; M Dhandhang Purwadi

    2011-01-01

    Warm water layer system is a protection system that protect the environment and the workers above of the reactor pool from radiation exposure which carried by the primary coolant. The system forms the warm water layer at the surface of reactor pool for about 1,5 m thick and temperature for about 8 to 10 °C slightly above of the reactor pool temperature. Computational fluid dynamics can be used to analyze the characteristics of the warm water layer. One of the powerful computational fluid dynamics software is FLUENT and it is used to analyze the warm water layer at the G.A. Siwabessy multi purpose reactor. The results show that the increasing of warm water inlet temperature can increase the warm water layer temperature range which the safety system required. But it does not effect to the warm water layer thickness and population. In the other hand, the increasing of warm water layer inlet flow can increase the warm water layer thickness but not to the warm water layer temperature range. The effectiveness of warm water layer initially starts at 15 m 3 /h and 50 °C of the warm water inlet flow and temperature. At this condition, the warm water layer can block the primary coolant to reach the reactor pool's surface. (author)

  6. Remobilization of southern African desert dune systems by twenty-first century global warming.

    Science.gov (United States)

    Thomas, David S G; Knight, Melanie; Wiggs, Giles F S

    2005-06-30

    Although desert dunes cover 5 per cent of the global land surface and 30 per cent of Africa, the potential impacts of twenty-first century global warming on desert dune systems are not well understood. The inactive Sahel and southern African dune systems, which developed in multiple arid phases since the last interglacial period, are used today by pastoral and agricultural systems that could be disrupted if climate change alters twenty-first century dune dynamics. Empirical data and model simulations have established that the interplay between dune surface erodibility (determined by vegetation cover and moisture availability) and atmospheric erosivity (determined by wind energy) is critical for dunefield dynamics. This relationship between erodibility and erosivity is susceptible to climate-change impacts. Here we use simulations with three global climate models and a range of emission scenarios to assess the potential future activity of three Kalahari dunefields. We determine monthly values of dune activity by modifying and improving an established dune mobility index so that it can account for global climate model data outputs. We find that, regardless of the emission scenario used, significantly enhanced dune activity is simulated in the southern dunefield by 2039, and in the eastern and northern dunefields by 2069. By 2099 all dunefields are highly dynamic, from northern South Africa to Angola and Zambia. Our results suggest that dunefields are likely to be reactivated (the sand will become significantly exposed and move) as a consequence of twenty-first century climate warming.

  7. Tropical cyclogenesis in warm climates simulated by a cloud-system resolving model

    Science.gov (United States)

    Fedorov, Alexey V.; Muir, Les; Boos, William R.; Studholme, Joshua

    2018-03-01

    Here we investigate tropical cyclogenesis in warm climates, focusing on the effect of reduced equator-to-pole temperature gradient relevant to past equable climates and, potentially, to future climate change. Using a cloud-system resolving model that explicitly represents moist convection, we conduct idealized experiments on a zonally periodic equatorial β-plane stretching from nearly pole-to-pole and covering roughly one-fifth of Earth's circumference. To improve the representation of tropical cyclogenesis and mean climate at a horizontal resolution that would otherwise be too coarse for a cloud-system resolving model (15 km), we use the hypohydrostatic rescaling of the equations of motion, also called reduced acceleration in the vertical. The simulations simultaneously represent the Hadley circulation and the intertropical convergence zone, baroclinic waves in mid-latitudes, and a realistic distribution of tropical cyclones (TCs), all without use of a convective parameterization. Using this model, we study the dependence of TCs on the meridional sea surface temperature gradient. When this gradient is significantly reduced, we find a substantial increase in the number of TCs, including a several-fold increase in the strongest storms of Saffir-Simpson categories 4 and 5. This increase occurs as the mid-latitudes become a new active region of TC formation and growth. When the climate warms we also see convergence between the physical properties and genesis locations of tropical and warm-core extra-tropical cyclones. While end-members of these types of storms remain very distinct, a large distribution of cyclones forming in the subtropics and mid-latitudes share properties of the two.

  8. 14 CFR 23.1111 - Turbine engine bleed air system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Turbine engine bleed air system. 23.1111... Induction System § 23.1111 Turbine engine bleed air system. For turbine engine bleed air systems, the following apply: (a) No hazard may result if duct rupture or failure occurs anywhere between the engine port...

  9. 14 CFR 23.1091 - Air induction system.

    Science.gov (United States)

    2010-01-01

    ... AIRWORTHINESS STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Powerplant Induction System § 23.1091 Air induction system. (a) The air induction system for each engine and auxiliary power unit... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Air induction system. 23.1091 Section 23...

  10. The development of air cooled condensation systems

    International Nuclear Information System (INIS)

    Bodas, J.

    1990-01-01

    EGI - Contracting/Engineering has had experience with the development of air cooled condensing systems since the 1950's. There are two accepted types of dry cooling systems,the direct and the indirect ones. Due to the fact that the indirect system has several advantages over the direct one, EGI's purpose was to develop an economic, reliable and efficient type of indirect cooling system, both for industrial and power station applications. Apart from system development, the main components of dry cooling plant have been developed as well. These are: the water-to-air heat exchangers; the direct contact (DC, or jet) condenser; the cooling water circulating pumps and recovery turbines; and the peak cooling/preheating units. As a result of this broad development work which was connected with intensive market activity, EGI has supplied about 50% of the dry cooling plants employed for large power stations all over the world. This means that today the cumulated capacity of power units using Heller type dry cooling systems supplied and contracted by EGI is over 6000 MW

  11. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming

    Science.gov (United States)

    Tait, Peter W.; Hanna, Elizabeth G.

    2015-01-01

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C–1.0 °C from already emitted CO2 will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments’ capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework’s application as a planning tool. PMID:26334285

  12. Future changes in coastal upwelling ecosystems with global warming: The case of the California Current System.

    Science.gov (United States)

    Xiu, Peng; Chai, Fei; Curchitser, Enrique N; Castruccio, Frederic S

    2018-02-12

    Coastal upwelling ecosystems are among the most productive ecosystems in the world, meaning that their response to climate change is of critical importance. Our understanding of climate change impacts on marine ecosystems is largely limited to the open ocean, mainly because coastal upwelling is poorly reproduced by current earth system models. Here, a high-resolution model is used to examine the response of nutrients and plankton dynamics to future climate change in the California Current System (CCS). The results show increased upwelling intensity associated with stronger alongshore winds in the coastal region, and enhanced upper-ocean stratification in both the CCS and open ocean. Warming of the open ocean forces isotherms downwards, where they make contact with water masses with higher nutrient concentrations, thereby enhancing the nutrient flux to the deep source waters of the CCS. Increased winds and eddy activity further facilitate upward nutrient transport to the euphotic zone. However, the plankton community exhibits a complex and nonlinear response to increased nutrient input, as the food web dynamics tend to interact differently. This analysis highlights the difficulty in understanding how the marine ecosystem responds to a future warming climate, given to range of relevant processes operating at different scales.

  13. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming

    Directory of Open Access Journals (Sweden)

    Peter W. Tait

    2015-08-01

    Full Text Available Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C–1.0 °C from already emitted CO2 will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments’ capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework’s application as a planning tool.

  14. A Conceptual Framework for Planning Systemic Human Adaptation to Global Warming.

    Science.gov (United States)

    Tait, Peter W; Hanna, Elizabeth G

    2015-08-31

    Human activity is having multiple, inter-related effects on ecosystems. Greenhouse gas emissions persisting along current trajectories threaten to significantly alter human society. At 0.85 °C of anthropogenic warming, deleterious human impacts are acutely evident. Additional warming of 0.5 °C-1.0 °C from already emitted CO₂ will further intensify extreme heat and damaging storm events. Failing to sufficiently address this trend will have a heavy human toll directly and indirectly on health. Along with mitigation efforts, societal adaptation to a warmer world is imperative. Adaptation efforts need to be significantly upscaled to prepare society to lessen the public health effects of rising temperatures. Modifying societal behaviour is inherently complex and presents a major policy challenge. We propose a social systems framework for conceptualizing adaptation that maps out three domains within the adaptation policy landscape: acclimatisation, behavioural adaptation and technological adaptation, which operate at societal and personal levels. We propose that overlaying this framework on a systems approach to societal change planning methods will enhance governments' capacity and efficacy in strategic planning for adaptation. This conceptual framework provides a policy oriented planning assessment tool that will help planners match interventions to the behaviours being targeted for change. We provide illustrative examples to demonstrate the framework's application as a planning tool.

  15. Effects of different warming patterns on the translocations of cadmium and copper in a soil-rice seedling system.

    Science.gov (United States)

    Ge, Liqiang; Cang, Long; Liu, Hui; Zhou, Dongmei

    2015-10-01

    Heavy-metal-polluted rice poses potential threats to food security and has received great attention in recent years, while how elevated temperature affects the translocation of heavy metals in soil-rice system is unclear. In this study, potting experiments were conducted in plant growth chambers for 24 days to evaluate the effects of different warming patterns on cadmium (Cd) and copper (Cu) migrations in soil-rice seedling system. Rice seedlings were cultivated under four different day/night temperature patterns: 25/18 °C (CK), 25/23 °C (N5), 30/18 °C (D5), and 30/23 °C (DN5), respectively. Non-contaminated soil (CS), Cd/Cu lightly polluted soil (LS), and highly polluted soil (HS) were chosen for experiments. The results showed that different warming patterns decreased soil pH and elevated available soil Cd/Cu concentrations. The shoot and root biomass were increased by 39.0-320 and 28.6-348 %, respectively. Warming induced significant (p cadmium translocation from root to shoot (about -four to nine times of CK), while warming changed the Cu concentration of shoot similarly to that of root and had no significant effects on Cu translocations in rice seedlings. Our study may provide improved understanding for Cd/Cu fates in soil-rice system by warming and imply that heavy metals had the higher environmental risk under the future global warming.

  16. Impact of management strategies on the global warming potential at the cropping system level.

    Science.gov (United States)

    Goglio, Pietro; Grant, Brian B; Smith, Ward N; Desjardins, Raymond L; Worth, Devon E; Zentner, Robert; Malhi, Sukhdev S

    2014-08-15

    Estimating the greenhouse gas (GHG) emissions from agricultural systems is important in order to assess the impact of agriculture on climate change. In this study experimental data supplemented with results from a biophysical model (DNDC) were combined with life cycle assessment (LCA) to investigate the impact of management strategies on global warming potential of long-term cropping systems at two locations (Breton and Ellerslie) in Alberta, Canada. The aim was to estimate the difference in global warming potential (GWP) of cropping systems due to N fertilizer reduction and residue removal. Reducing the nitrogen fertilizer rate from 75 to 50 kg N ha(-1) decreased on average the emissions of N2O by 39%, NO by 59% and ammonia volatilisation by 57%. No clear trend for soil CO2 emissions was determined among cropping systems. When evaluated on a per hectare basis, cropping systems with residue removal required 6% more energy and had a little change in GWP. Conversely, when evaluated on the basis of gigajoules of harvestable biomass, residue removal resulted in 28% less energy requirement and 33% lower GWP. Reducing nitrogen fertilizer rate resulted in 18% less GWP on average for both functional units at Breton and 39% less GWP at Ellerslie. Nitrous oxide emissions contributed on average 67% to the overall GWP per ha. This study demonstrated that small changes in N fertilizer have a minimal impact on the productivity of the cropping systems but can still have a substantial environmental impact. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  17. 14 CFR 23.1109 - Turbocharger bleed air system.

    Science.gov (United States)

    2010-01-01

    ... Induction System § 23.1109 Turbocharger bleed air system. The following applies to turbocharged bleed air... vapors following any probable failure or malfunction of the engine exhaust, hydraulic, fuel, or oil...

  18. Roadmaps to Transition Countries to 100% Clean, Renewable Energy for All Purposes to Curtail Global Warming, Air Pollution, and Energy Risk

    Science.gov (United States)

    Jacobson, Mark Z.

    2017-10-01

    Solving the problems of global warming, air pollution, and energy security requires a massive effort by individuals, communities, businesses, nonprofits, and policy makers around the world. The first step in that process is to have a plan. To that end, roadmaps to transition 139 countries of the world to 100% clean, renewable wind, water, and solar power for all energy purposes (electricity, transportation, heating, cooling, industry, agriculture, forestry, and fishing) by 2050, with 80% by 2030, have been developed. The evolution, characteristics, and impacts to date of these plans are briefly described.

  19. Thermal comfort and IAQ assessment of under-floor air distribution system integrated with personalized ventilation in hot and humid climate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ruixin [Department of Building, National University of Singapore (Singapore); International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark (Denmark); Sekhar, S.C. [Department of Building, National University of Singapore (Singapore); Melikov, A.K. [International Centre for Indoor Environment and Energy, Department of Civil Engineering, Technical University of Denmark (Denmark)

    2010-09-15

    The potential for improving occupants' thermal comfort with personalized ventilation (PV) system combined with under-floor air distribution (UFAD) system was explored through human response study. The hypothesis was that cold draught at feet can be reduced when relatively warm air is supplied by UFAD system and uncomfortable sensation as ''warm head'' can be reduced by the PV system providing cool and fresh outdoor air at the facial level. A study with 30 human subjects was conducted in a Field Environmental Chamber. The chamber was served by two dedicated systems - a primary air handling unit (AHU) for 100% outdoor air that is supplied through the PV air terminal devices and a secondary AHU for 100% recirculated air that is supplied through UFAD outlets. Responses of the subjects to the PV-UFAD system were collected at various room air and PV air temperature combinations. The analyses of the results obtained reveal improved acceptability of perceived air quality and improved thermal sensation with PV-UFAD in comparison with the reference case of UFAD alone or mixing ventilation with ceiling supply diffuser. The local thermal sensation at the feet was also improved when warmer UFAD supply air temperature was adopted in the PV-UFAD system. (author)

  20. Roots Air Management System with Integrated Expander

    Energy Technology Data Exchange (ETDEWEB)

    Stretch, Dale [Eaton Corporation, Menomonee Falls, WI (United States); Wright, Brad [Eaton Corporation, Menomonee Falls, WI (United States); Fortini, Matt [Eaton Corporation, Menomonee Falls, WI (United States); Fink, Neal [Ballard Power Systems, Burnaby, BC (Canada); Ramadan, Bassem [Kettering Univ., Flint, MI (United States); Eybergen, William [Eaton Corporation, Menomonee Falls, WI (United States)

    2016-07-06

    PEM fuel cells remain an emerging technology in the vehicle market with several cost and reliability challenges that must be overcome in order to increase market penetration and acceptance. The DOE has identified the lack of a cost effective, reliable, and efficient air supply system that meets the operational requirements of a pressurized PEM 80kW fuel cell as one of the major technological barriers that must be overcome. This project leveraged Roots positive displacement development advancements and demonstrated an efficient and low cost fuel cell air management system. Eaton built upon its P-Series Roots positive displacement design and shifted the peak efficiency making it ideal for use on an 80kW PEM stack. Advantages to this solution include: • Lower speed of the Roots device eliminates complex air bearings present on other systems. • Broad efficiency map of Roots based systems provides an overall higher drive cycle fuel economy. • Core Roots technology has been developed and validated for other transportation applications. Eaton modified their novel R340 Twin Vortices Series (TVS) Roots-type supercharger for this application. The TVS delivers more power and better fuel economy in a smaller package as compared to other supercharger technologies. By properly matching the helix angle with the rotor’s physical aspect ratio, the supercharger’s peak efficiency can be moved to the operating range where it is most beneficial for the application. The compressor was designed to meet the 90 g/s flow at a pressure ratio of 2.5, similar in design to the P-Series 340. A net shape plastic expander housing with integrated motor and compressor was developed to significantly reduce the cost of the system. This integrated design reduced part count by incorporating an overhung expander and motor rotors into the design such that only four bearings and two shafts were utilized.

  1. The limited streamer tubes system for the SLD warm iron calorimeter

    International Nuclear Information System (INIS)

    Benvenuti, A.C.; Camanzi, B.; Piemontese, L.; Zucchelli, P.; Calcaterra, A.; De Sangro, R.; De Simone, P.; De Simone, S.; Gallinaro, M.; Peruzzi, I.; Piccolo, M.; Bacchetta, N.; Bisello, D.; Castro, A.; Galvagni, S.; Loreti, M.; Pescara, L.; Wyss, J.; Battiston, R.; Biasini, M.; Bilei, G.M.; Checcucci, B; Mancinelli, G.; Mantovani, G.; Pauluzzi, M.; Santocchia, A.; Servoli, L.; Carpinelli, M.; Castaldi, R.; Cazzola, U.; Dell'Orso, R.; Pieroni, E.; Vannini, C.; Verdini, P.G.; Byers, B.L.; Escalera, J.; Kharakh, D.; Messner, R.L.; Zdarko, R.W.; Johnson, J.R.

    1992-01-01

    The SLD detector at the Stanford Linear Accelerator Center is a general purpose device for studying e + ε - interaction at the Z 0 . The SLD calorimeter system consists of two parts: a lead Liquid Argon Calorimeter (LAC) with both electromagnetic (22 radiation lengths) and hadronic sections (2.8 absorption lengths) housed inside the coil, and the Warm Ion limited streamer tubes Calorimeter (WIC) outside the coil which uses as radiator the iron of the flux return for the magnetic field. The WIC completes the measurement of the hadronic shower energy (∼85% on average is contained in the LAC) and it provides identification and tracking for muons over 99% of the solid angle. In this note we report on the construction, test and commissioning of such a large system

  2. Sorption Mechanisms for Mercury Capture in Warm Post-Gasification Gas Clean-Up Systems

    Energy Technology Data Exchange (ETDEWEB)

    Jost Wendt; Sung Jun Lee; Paul Blowers

    2008-09-30

    The research was directed towards a sorbent injection/particle removal process where a sorbent may be injected upstream of the warm gas cleanup system to scavenge Hg and other trace metals, and removed (with the metals) within the warm gas cleanup process. The specific objectives of this project were to understand and quantify, through fundamentally based models, mechanisms of interaction between mercury vapor compounds and novel paper waste derived (kaolinite + calcium based) sorbents (currently marketed under the trade name MinPlus). The portion of the research described first is the experimental portion, in which sorbent effectiveness to scavenge metallic mercury (Hg{sup 0}) at high temperatures (>600 C) is determined as a function of temperature, sorbent loading, gas composition, and other important parameters. Levels of Hg{sup 0} investigated were in an industrially relevant range ({approx} 25 {micro}g/m{sup 3}) although contaminants were contained in synthetic gases and not in actual flue gases. A later section of this report contains the results of the complementary computational results.

  3. Progress report for project modeling Arctic barrier island-lagoon system response to projected Arctic warming

    Science.gov (United States)

    Erikson, Li H.; Gibbs, Ann E.; Richmond, Bruce M.; Storlazzi, Curt; B.M. Jones,

    2012-01-01

    Changes in Arctic coastal ecosystems in response to global warming may be some of the most severe on the planet. A better understanding and analysis of the rates at which these changes are expected to occur over the coming decades is crucial in order to delineate high-priority areas that are likely to be affected by climate changes. In this study we investigate the likelihood of changes to habitat-supporting barrier island – lagoon systems in response to projected changes in atmospheric and oceanographic forcing associated with Arctic warming. To better understand the relative importance of processes responsible for the current and future coastal landscape, key parameters related to increasing arctic temperatures are investigated and used to establish boundary conditions for models that simulate barrier island migration and inundation of deltaic deposits and low-lying tundra. The modeling effort investigates the dominance and relative importance of physical processes shaping the modern Arctic coastline as well as decadal responses due to projected conditions out to the year 2100.

  4. Addressing Global Warming, Air Pollution, Energy Security, and Jobs with Roadmaps for Changing the All-Purpose Energy Infrastructure of the 50 United States

    Science.gov (United States)

    Jacobson, M. Z.

    2014-12-01

    Global warming, air pollution, and energy insecurity are three of the most significant problems facing the world today. This talk discusses the development of technical and economic plans to convert the energy infrastructure of each of the 50 United States to those powered by 100% wind, water, and sunlight (WWS) for all purposes, namely electricity, transportation, industry, and heating/cooling, after energy efficiency measures have been accounted for. The plans call for all new energy to be WWS by 2020, ~80% conversion of existing energy by 2030, and 100% by 2050 through aggressive policy measures and natural transition. Resource availability, footprint and spacing areas required, jobs created versus lost, energy costs, avoided costs from air pollution mortality and morbidity and climate damage, and methods of ensuring reliability of the grid are discussed. Please see http://web.stanford.edu/group/efmh/jacobson/Articles/I/WWS-50-USState-plans.html

  5. Human Exposure Assessment in Air Pollution Systems

    Directory of Open Access Journals (Sweden)

    Junfeng (Jim Zhang

    2002-01-01

    Full Text Available The air pollution problem can be depicted as a system consisting of several basic components: source, concentration, exposure, dose, and adverse effects. Exposure, the contact between an agent (e.g., an air pollutant and a target (e.g., a human respiratory tract, is the key to linking the pollution source and health effects. Human exposure to air pollutants depends on exposure concentration and exposure duration. Exposure concentration is the concentration of a pollutant at a contact boundary, which usually refers to the human breathing zone. However, ambient concentrations of regulated pollutants at monitoring sites have been measured in practice to represent actual exposure. This can be a valid practice if the pollutants are ones that are predominantly generated outdoors and if the monitoring sites are appropriately selected to reflect where people are. Results from many exposure studies indicate that people are very likely to receive the greatest exposure to many toxic air pollutants not outside but inside places such as homes, offices, and automobiles. For many of these pollutants, major sources of exposure can be quite different from major sources of emission. This is because a large emission source can have a very small value of exposure effectiveness, i.e., the fraction of pollutant released from a source that actually reaches the human breathing zone. Exposure data are crucial to risk management decisions for setting priorities, selecting cost-effective approaches to preventing or reducing risks, and evaluating risk mitigation efforts. Measurement or estimate of exposure is essential but often inadequately addressed in environmental epidemiologic studies. Exposure can be quantified using direct or indirect measurement methods, depending upon the purpose of exposure assessment and the availability of relevant data. The rapidly developing battery and electronic technologies as well as advancements in molecular biology are expected to

  6. Albedo impact on the suitability of biochar systems to mitigate global warming.

    Science.gov (United States)

    Meyer, Sebastian; Bright, Ryan M; Fischer, Daniel; Schulz, Hardy; Glaser, Bruno

    2012-11-20

    Biochar application to agricultural soils can change the surface albedo which could counteract the climate mitigation benefit of biochar systems. However, the size of this impact has not yet been quantified. Based on empirical albedo measurements and literature data of arable soils mixed with biochar, a model for annual vegetation cover development based on satellite data and an assessment of the annual development of surface humidity, an average mean annual albedo reduction of 0.05 has been calculated for applying 30-32 Mg ha(-1) biochar on a test field near Bayreuth, Germany. The impact of biochar production and application on the carbon cycle and on the soil albedo was integrated into the greenhouse gas (GHG) balance of a modeled pyrolysis based biochar system via the computation of global warming potential (GWP) characterization factors. The analysis resulted in a reduction of the overall climate mitigation benefit of biochar systems by 13-22% due to the albedo change as compared to an analysis which disregards the albedo effect. Comparing the use of the same quantity of biomass in a biochar system to a bioenergy district heating system which replaces natural gas combustion, bioenergy heating systems achieve 99-119% of the climate benefit of biochar systems according to the model calculation.

  7. Operating systems in the air transportation environment.

    Science.gov (United States)

    Cherry, G. W.

    1971-01-01

    Consideration of the problems facing air transport at present, and to be expected in the future. In the Northeast Corridor these problems involve community acceptance, airway and airport congestion and delays, passenger acceptance, noise reduction, and improvements in low-density short-haul economics. In the development of a superior short-haul operating system, terminal-configured vs cruise-configured vehicles are evaluated. CTOL, STOL, and VTOL aircraft of various types are discussed. In the field of noise abatement, it is shown that flight procedural techniques are capable of supplementing ?quiet engine' technology.

  8. Daytime warming has stronger negative effects on soil nematodes than night-time warming

    OpenAIRE

    Yan, Xiumin; Wang, Kehong; Song, Lihong; Wang, Xuefeng; Wu, Donghui

    2017-01-01

    Warming of the climate system is unequivocal, that is, stronger warming during night-time than during daytime. Here we focus on how soil nematodes respond to the current asymmetric warming. A field infrared heating experiment was performed in the western of the Songnen Plain, Northeast China. Three warming modes, i.e. daytime warming, night-time warming and diurnal warming, were taken to perform the asymmetric warming condition. Our results showed that the daytime and diurnal warming treatmen...

  9. Modeling of Energy-saving System of Conditioning Mine Air for Shallow Underground Mines

    Science.gov (United States)

    Nikolaev, Alexandr; Miftakhov, Timur; Nikolaeva, Evgeniya

    2017-11-01

    Mines of Verkhnekamsk potassium-magnesium salt deposit in Perm Krai can be subsumed under shallow mines (depth less than 500 meters). At the present moment in shallow underground mines the are problem of condensate formation in large quantities, when ventilation warm seasons of the year. This problem is more actual for salt mine, where during contact between water and potassium-magnesium ore produced electrolyte, which give rise wear of equipment. For prevent/quantity reduction condensate formation in mine used system of conditioning (refrigerating and dehumidifying) mine air (ACS). However, application this system is limited by reason of tremendous costs of electric energy for their work.

  10. Isotopic composition of ice core air reveals abrupt Antarctic warming during and after Heinrich Event 1a

    Science.gov (United States)

    Morgan, J. D.; Bereiter, B.; Baggenstos, D.; Kawamura, K.; Shackleton, S. A.; Severinghaus, J. P.

    2017-12-01

    Antarctic temperature variations during Heinrich events, as recorded by δ18O­ice­, generally show more gradual changes than the abrupt warmings seen in Greenland ice. However, quantitative temperature interpretation of the water isotope temperature proxy is difficult as the relationship between δ18Oice and temperature is not constant through time. Fortunately, ice cores offer a second temperature proxy based on trapped gases. During times of surface warming, thermal fractionation of gases in the column of unconsolidated snow (firn) on top of the ice sheet results in isotopically heavier nitrogen (N2) and argon (Ar) being trapped in the ice core bubbles. During times of surface cooling, isotopically lighter gases are trapped. Measurements of δ15N and δ40Ar can therefore be used, in combination with a model for the height of the column of firn, to quantitatively reconstruct surface temperatures. In the WAIS Divide Ice Core, the two temperature proxies show a brief disagreement during Heinrich Stadial 1. Despite δ18Oice recording relatively constant temperature, the nitrogen and argon isotopes imply an abrupt warming between 16 and 15.8 kyr BP, manifest as an abrupt 1.25oC increase in the firn temperature gradient. To our knowledge, this would be the first evidence that such abrupt climate change has been recorded in an Antarctic climate proxy. If confirmed by more detailed studies, this event may represent warming due to an extreme southward shift of the Earth's thermal equator (and the southern hemisphere westerly wind belt), caused by the 16.1 ka Heinrich Event.

  11. Using Unmanned Air Systems to Monitor Methane in the Atmosphere

    Science.gov (United States)

    Clow, Jacqueline; Smith, Jeremy Christopher

    2016-01-01

    Methane is likely to be an important contributor to global warming, and our current knowledge of its sources, distributions, and transport is insufficient. It is estimated that there could be from 7.5 to 400 billion tons carbon-equivalent of methane in the arctic region, a broad range that is indicative of the uncertainty within the Earth Science community. Unmanned Air Systems (UASs) are often used for combat or surveillance by the military, but they also have been used for Earth Science field missions. In this study, we will analyze the utility of the NASA Global Hawk and the Aurora Flight Sciences Orion UASs compared to the manned DC-8 aircraft for conducting a methane monitoring mission. The mission will focus on the measurement of methane along the boundaries of Arctic permafrost thaw and melting glaciers. The use of Long Endurance UAS brings a new range of possibilities including the ability to obtain long- term and persistent observations and to significantly augment methane measurements/retrievals collected by satellite. Furthermore, we discuss the future of long endurance UAS and their potential for science applications in the next twenty to twenty-five years.

  12. Design of a Hydraulic Motor System Driven by Compressed Air

    OpenAIRE

    Shaw, Dein; Yu, Jyun-Jhe; Chieh, Cheng

    2013-01-01

    This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power....

  13. Optical system for trapping particles in air.

    Science.gov (United States)

    Kampmann, R; Chall, A K; Kleindienst, R; Sinzinger, S

    2014-02-01

    An innovative optical system for trapping particles in air is presented. We demonstrate an optical system specifically optimized for high precision positioning of objects with a size of several micrometers within a nanopositioning and nanomeasuring machine (NPMM). Based on a specification sheet, an initial system design was calculated and optimized in an iterative design process. By combining optical design software with optical force simulation tools, a highly efficient optical system was developed. Both components of the system, which include a refractive double axicon and a parabolic ring mirror, were fabricated by ultra-precision turning. The characterization of the optical elements and the whole system, especially the force simulations based on caustic measurements, represent an important interim result for the subsequently performed trapping experiments. The caustic of the trapping beam produced by the system was visualized with the help of image processing techniques. Finally, we demonstrated the unique efficiency of the configuration by reproducibly trapping fused silica spheres with a diameter of 10 μm at a distance of 2.05 mm from the final optical surface.

  14. Impact of management strategies on the global warming potential at the cropping system level

    Energy Technology Data Exchange (ETDEWEB)

    Goglio, Pietro; Grant, Brian B.; Smith, Ward N. [Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, K.W. Neatby Building, Ottawa, Ontario K1A 0C6 (Canada); Desjardins, Raymond L., E-mail: ray.desjardins@agr.gc.ca [Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, K.W. Neatby Building, Ottawa, Ontario K1A 0C6 (Canada); Worth, Devon E. [Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, K.W. Neatby Building, Ottawa, Ontario K1A 0C6 (Canada); Zentner, Robert [Swift Current Research Station, Swift Current, Saskatchewan S0E 1A0 (Canada); Malhi, Sukhdev S. [Melfort Research Farm, PO Box 1240, Melfort, Saskatchewan S0E 1A0 (Canada)

    2014-08-15

    Estimating the greenhouse gas (GHG) emissions from agricultural systems is important in order to assess the impact of agriculture on climate change. In this study experimental data supplemented with results from a biophysical model (DNDC) were combined with life cycle assessment (LCA) to investigate the impact of management strategies on global warming potential of long-term cropping systems at two locations (Breton and Ellerslie) in Alberta, Canada. The aim was to estimate the difference in global warming potential (GWP) of cropping systems due to N fertilizer reduction and residue removal. Reducing the nitrogen fertilizer rate from 75 to 50 kg N ha{sup −1} decreased on average the emissions of N{sub 2}O by 39%, NO by 59% and ammonia volatilisation by 57%. No clear trend for soil CO{sub 2} emissions was determined among cropping systems. When evaluated on a per hectare basis, cropping systems with residue removal required 6% more energy and had a little change in GWP. Conversely, when evaluated on the basis of gigajoules of harvestable biomass, residue removal resulted in 28% less energy requirement and 33% lower GWP. Reducing nitrogen fertilizer rate resulted in 18% less GWP on average for both functional units at Breton and 39% less GWP at Ellerslie. Nitrous oxide emissions contributed on average 67% to the overall GWP per ha. This study demonstrated that small changes in N fertilizer have a minimal impact on the productivity of the cropping systems but can still have a substantial environmental impact. - Highlights: • LCA was combined with DNDC model to estimate the GWP of a cropping system. • N{sub 2}O, NO and NH{sub 3} flux increased by 39% under the higher fertilizer rate. • A change from 75 to 50 kg N ha{sup −1} reduced the GWP per ha and GJ basis by 18%. • N{sub 2}O emissions contributed 67% to the overall GWP of the cropping system. • Small changes in N fertilizer can have a substantial environmental impact.

  15. INTERFEROMETRIC EVIDENCE FOR RESOLVED WARM DUST IN THE DQ TAU SYSTEM

    International Nuclear Information System (INIS)

    Boden, Andrew F.; Sargent, Anneila I.; Carpenter, John M.; Akeson, Rachel L.; Ciardi, David R.; Bary, Jeffrey S.; Skrutskie, Michael F.

    2009-01-01

    We report on near-infrared (IR) interferometric observations of the double-lined pre-main sequence binary system DQ Tau. We model these data with a visual orbit for DQ Tau supported by the spectroscopic orbit and analysis of Mathieu et al. Further, DQ Tau exhibits significant near-IR excess; modeling our data requires inclusion of near-IR light from an 'excess' source. Remarkably, the excess source is resolved in our data, similar in scale to the binary itself (∼0.2 AU at apastron), rather than the larger circumbinary disk (∼0.4 AU radius). Our observations support the Mathieu et al. and Carr et al. inference of significant warm material near the DQ Tau binary.

  16. Refrigeration Playbook: Natural Refrigerants; Selecting and Designing Energy-Efficient Commercial Refrigeration Systems That Use Low Global Warming Potential Refrigerants

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Caleb [CTA Architects Engineers, Boise, ID (United States); Reis, Chuck [CTA Architects Engineers, Boise, ID (United States); Nelson, Eric [CTA Architects Engineers, Boise, ID (United States); Armer, James [CTA Architects Engineers, Boise, ID (United States); Arthur, Rob [CTA Architects Engineers, Boise, ID (United States); Heath, Richard [CTA Architects Engineers, Boise, ID (United States); Rono, James [CTA Architects Engineers, Boise, ID (United States); Hirsch, Adam [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Doebber, Ian [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2015-03-01

    This report provides guidance for selecting and designing energy efficient commercial refrigeration systems using low global warming potential refrigerants. Refrigeration systems are generally the largest energy end use in a supermarket type building, often accounting for more than half of a building's energy consumption.

  17. 46 CFR 197.310 - Air compressor system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Air compressor system. 197.310 Section 197.310 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE OCCUPATIONAL SAFETY AND HEALTH STANDARDS GENERAL PROVISIONS Commercial Diving Operations Equipment § 197.310 Air compressor system. A compressor used to supply breathing air to a diver...

  18. One man electrochemical air revitalization system

    Science.gov (United States)

    Huddleston, J. C.; Aylward, J. R.

    1975-01-01

    An integrated water vapor electrolysis (WVE) hydrogen depolarized CO2 concentrator (HDC) system sized for one man support over a wide range of inlet air conditions was designed, fabricated, and tested. Data obtained during 110 days of testing verified that this system can provide the necessary oxygen, CO2 removal, and partial humidity control to support one man (without exceeding a cabin partial pressure of 3.0 mmHg for CO2 and while maintaining a 20% oxygen level), when operated at a WVE current of 50 amperes and an HDC current of 18 amperes. An evaluation to determine the physical properties of tetramethylammonium bicarbonate (TMAC) and hydroxide was made. This provides the necessary electrolyte information for designing an HDC cell using TMAC.

  19. A user-friendly earth system model of low complexity: the ESCIMO system dynamics model of global warming towards 2100

    Science.gov (United States)

    Randers, Jorgen; Golüke, Ulrich; Wenstøp, Fred; Wenstøp, Søren

    2016-11-01

    We have made a simple system dynamics model, ESCIMO (Earth System Climate Interpretable Model), which runs on a desktop computer in seconds and is able to reproduce the main output from more complex climate models. ESCIMO represents the main causal mechanisms at work in the Earth system and is able to reproduce the broad outline of climate history from 1850 to 2015. We have run many simulations with ESCIMO to 2100 and beyond. In this paper we present the effects of introducing in 2015 six possible global policy interventions that cost around USD 1000 billion per year - around 1 % of world GDP. We tentatively conclude (a) that these policy interventions can at most reduce the global mean surface temperature - GMST - by up to 0.5 °C in 2050 and up to 1.0 °C in 2100 relative to no intervention. The exception is injection of aerosols into the stratosphere, which can reduce the GMST by more than 1.0 °C in a decade but creates other serious problems. We also conclude (b) that relatively cheap human intervention can keep global warming in this century below +2 °C relative to preindustrial times. Finally, we conclude (c) that run-away warming is unlikely to occur in this century but is likely to occur in the longer run. The ensuing warming is slow, however. In ESCIMO, it takes several hundred years to lift the GMST to +3 °C above preindustrial times through gradual self-reinforcing melting of the permafrost. We call for research to test whether more complex climate models support our tentative conclusions from ESCIMO.

  20. Modeling the air-sea feedback system of Madeira Island

    Science.gov (United States)

    Pullen, Julie; Caldeira, Rui; Doyle, James D.; May, Paul; Tomé, Ricardo

    2017-07-01

    A realistic nested data-assimilating two-way coupled ocean/atmosphere modeling study (highest resolution 2 km) of Madeira Island was conducted for June 2011, when conditions were favorable for atmospheric vortex shedding. The simulation's island lee region exhibited relatively cloud-free conditions, promoting warmer ocean temperatures (˜2°C higher than adjacent waters). The model reasonably reproduced measured fields at 14 meteorological stations, and matched the dimensions and magnitude of the warm sea surface temperature (SST) wake imaged by satellite. The warm SSTs in the wake are shown to imprint onto the atmospheric boundary layer (ABL) over several diurnal cycles by modulating the ABL depth up to ˜200-500 m. The erosion and dissipation of the warm ocean wake overnight was aided by atmospheric drainage flow and offshore advection of cold air (ΔT = 2°C) that produced strong upward heat fluxes (˜50 W/m2 sensible and ˜250 W/m2 latent) on an episodic basis. Nevertheless, the warm wake was never entirely eroded at night due to the cumulative effect of the diurnal cycle. The spatial pattern of the diurnal warming varied day-to-day in location and extent. Significant mutual interaction of the oceanic and atmospheric boundary layers was diagnosed via fluxes and temperature cross sections and reinforced by sensitivity runs. The simulation produces for the first time the interactive nature of the ocean and atmosphere boundary layers in the warm wake region of an island with complex terrain.

  1. Air Quality System (AQS) Monitoring Network, EPA OAR OAQPS

    Data.gov (United States)

    U.S. Environmental Protection Agency — This GIS dataset contains points which depict air quality monitors within EPA's Air Quality System (AQS) monitoring network. This dataset is updated weekly to...

  2. Computational Fluid Dynamic Modeling of Horizontal Air-Ground Heat Exchangers (HAGHE for HVAC Systems

    Directory of Open Access Journals (Sweden)

    Paolo Maria Congedo

    2014-12-01

    Full Text Available In order to satisfy the requirements of Directive 2010/31/EU for Zero Energy Buildings (ZEB, innovative solutions were investigated for building HVAC systems. Horizontal air-ground heat exchangers (HAGHE offer a significant contribution in reducing energy consumption for ventilation, using the thermal energy stored underground, in order to pre-heat or pre-cool the ventilation air, in winter and summer, respectively. This is particularly interesting in applications for industrial, commercial and education buildings where keeping the indoor air quality under control is extremely important. Experimental measurements show that, throughout the year, the outside air temperature fluctuations are mitigated at sufficient ground depth (about 3 m because of the high thermal inertia of the soil, the ground temperature is relatively constant and instead higher than that of the outside air in winter and lower in summer. The study aims to numerically investigate the behavior of HAGHE by varying the air flow rate and soil conductivity in unsteady conditions by using annual weather data of South-East Italy. The analysis shows that, in warm climates, the HAGHE brings a real advantage for only a few hours daily in winter, while it shows significant benefits in the summer for the cooling of ventilation air up to several temperature degrees, already by a short pipe.

  3. Variable volume combustor with an air bypass system

    Science.gov (United States)

    Johnson, Thomas Edward; Ziminsky, Willy Steve; Ostebee, Heath Michael; Keener, Christopher Paul

    2017-02-07

    The present application provides a combustor for use with flow of fuel and a flow of air in a gas turbine engine. The combustor may include a number of micro-mixer fuel nozzles positioned within a liner and an air bypass system position about the liner. The air bypass system variably allows a bypass portion of the flow of air to bypass the micro-mixer fuel nozzles.

  4. Implementation of methane cycling for deep time, global warming simulations with the DCESS Earth System Model (Version 1.2)

    DEFF Research Database (Denmark)

    Shaffer, Gary; Villanueva, Esteban Fernández; Rondanelli, Roberto

    2017-01-01

    Geological records reveal a number of ancient, large and rapid negative excursions of carbon-13 isotope. Such excursions can only be explained by massive injections of depleted carbon to the Earth System over a short duration. These injections may have forced strong global warming events, sometimes....... With this improved DCESS model version and paleo-reconstructions, we are now better armed to gauge the amounts, types, time scales and locations of methane injections driving specific, observed deep time, global warming events......., or from warming-induced dissociation of methane hydrate, a solid compound of methane and water found in ocean sediments. As a consequence of the ubiquity and importance of methane in major Earth events, Earth System models should include a comprehensive treatment of methane cycling but such a treatment...

  5. Long-term pattern and magnitude of soil carbon feedback to the climate system in a warming world.

    Science.gov (United States)

    Melillo, J M; Frey, S D; DeAngelis, K M; Werner, W J; Bernard, M J; Bowles, F P; Pold, G; Knorr, M A; Grandy, A S

    2017-10-06

    In a 26-year soil warming experiment in a mid-latitude hardwood forest, we documented changes in soil carbon cycling to investigate the potential consequences for the climate system. We found that soil warming results in a four-phase pattern of soil organic matter decay and carbon dioxide fluxes to the atmosphere, with phases of substantial soil carbon loss alternating with phases of no detectable loss. Several factors combine to affect the timing, magnitude, and thermal acclimation of soil carbon loss. These include depletion of microbially accessible carbon pools, reductions in microbial biomass, a shift in microbial carbon use efficiency, and changes in microbial community composition. Our results support projections of a long-term, self-reinforcing carbon feedback from mid-latitude forests to the climate system as the world warms. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  6. Machine & electrical double control air dryer for vehicle air braking system

    Science.gov (United States)

    Zhang, Xuan; Yang, Liu; Wang, Xian Yan; Tan, Xiao Yan; Wang, Wei

    2017-09-01

    As is known to all, a vehicle air brake system, in which usually contains moisture. To solve the problem, it is common to use air dryer to dry compressed air effectively and completely remove the moisture and oil of braking system. However, the existing air dryer is not suitable for all commercial vehicles. According to the operational status of the new energy vehicles in the initial operating period, the structure design principle of the machine & electric control air dryer is expounded from the aspects of the structure and operating principle, research & development process.

  7. Roles of nuclear power system in the presence of uncertainties from global warming

    International Nuclear Information System (INIS)

    Kiriyama, Eriko; Iwata, Shuichi

    2005-01-01

    Environmental 'bads' like carbon dioxide are not simply incorporated in the market system. The costs involved, however, do not really reflect the inherent value of the environment, or what it is worth to them. This study focuses on the uncertainty of CO 2 emission credits. Assigning economic values to environmental goods and services is complex, but it is an area that is receiving considerable attention from environmental economists. The purpose of this study is to analyze the value of an investment in power generation assets that do not emit CO 2 . To deal with the CO 2 emission credit, we built new models based on the real option model by Pindyck (2000). In the modern, market-based financial systems that dominate the global economy, the value of a resource is represented by the price that an individual or a group is willing to pay for it. Managing CO 2 emission limitations will be a critical aspect of power generation systems. And it will be increasingly so as the emphasis on global environmental issues continues to rise. In order to secure the effectiveness of measures against global warming, we should reconsider the role of nuclear power systems. (author)

  8. Evaluation of AirGIS: a GIS-based air pollution and human exposure modelling system

    DEFF Research Database (Denmark)

    Ketzel, Matthias; Berkowicz, Ruwim; Hvidberg, Martin

    2011-01-01

    shows, in general, a good performance for both long-term averages (annual and monthly averages), short-term averages (hourly and daily) as well as when reproducing spatial variation in air pollution concentrations. Some shortcomings and future perspectives of the system are discussed too.......This study describes in brief the latest extensions of the Danish Geographic Information System (GIS)-based air pollution and human exposure modelling system (AirGIS), which has been developed in Denmark since 2001 and gives results of an evaluation with measured air pollution data. The system...

  9. Information Systems Strategy in Air Transport

    Science.gov (United States)

    1993-09-01

    Brown, D. R., An Experimental Approach to Oroanization Development, 3rd ed., Prentice-Hall Inc., 1988. Henderson, Danna , "Consistent profit growth is...basically Southwest," Air Transport World, V19, September 1982. Henderson, Danna , "Muse air makes bold moves before possible merger with Southwest...34 Air Transport World, V22, June 1985. Henderson, Danna , "Southwest airlines: different but very much the same," Air Transport World, V24, May 1987

  10. A new air quality monitoring and early warning system: Air quality assessment and air pollutant concentration prediction.

    Science.gov (United States)

    Yang, Zhongshan; Wang, Jian

    2017-10-01

    Air pollution in many countries is worsening with industrialization and urbanization, resulting in climate change and affecting people's health, thus, making the work of policymakers more difficult. It is therefore both urgent and necessary to establish amore scientific air quality monitoring and early warning system to evaluate the degree of air pollution objectively, and predict pollutant concentrations accurately. However, the integration of air quality assessment and air pollutant concentration prediction to establish an air quality system is not common. In this paper, we propose a new air quality monitoring and early warning system, including an assessment module and forecasting module. In the air quality assessment module, fuzzy comprehensive evaluation is used to determine the main pollutants and evaluate the degree of air pollution more scientifically. In the air pollutant concentration prediction module, a novel hybridization model combining complementary ensemble empirical mode decomposition, a modified cuckoo search and differential evolution algorithm, and an Elman neural network, is proposed to improve the forecasting accuracy of six main air pollutant concentrations. To verify the effectiveness of this system, pollutant data for two cities in China are used. The result of the fuzzy comprehensive evaluation shows that the major air pollutants in Xi'an and Jinan are PM 10 and PM 2.5 respectively, and that the air quality of Xi'an is better than that of Jinan. The forecasting results indicate that the proposed hybrid model is remarkably superior to all benchmark models on account of its higher prediction accuracy and stability. Copyright © 2017 Elsevier Inc. All rights reserved.

  11. Sustainable groundwater management system based on the regional hydrological cycle in the warm humid country, Japan

    Science.gov (United States)

    Shimada, J.; Crest Kumamoto Groundwater Team

    2011-12-01

    The increase of precipitation variability with the global warming and the rapid population growth lead to the shortage of water resources on a global scale. Groundwater bocome attracted as a relatively stable water resource because of its larger reservoir and a longer residence time. As our country belongs to a warm humid climate with much precipitation and a steep topography, the regional hydrological cycle is extremely active. Surface water could be taken easily and was often used to a water supply until now, but recently groundwater is taking the place of surface water because of the stability of water supply. While in our hydro-climatic condition, the sustainable use of groundwater is possible under the appropriative management, that is, groundwater pumping rate does not exceed the recharge rate in a basin. For the sustainable use of groundwater resources, this project aims to develop new technologies relating to the quantity and quality aspects of groundwater resources. For the precise understanding of groundwater flow system, new technologies will be developed, like frequency changeable electric resistivity exploration method to evaluate an aquifer structure. There are many problems about groundwater quality including nitrate-nitrogen contamination and toxic substances from the domestic and industrial waste disposals. It is necessary to understand the production mechanism to prevent groundwater contamination and the degradation process of nitrate-nitrogen contamination to improve the water quality. Therefore this project will develop new technologies including the reduction of NO3=N and natural toxic substances loads before groundwater recharge, the on-site removal of contaminants from aquifers, and simple and effective equipment to improve groundwater quality after pumping. Furthermore, this project will also develop a new biological monitoring technique for local groundwater users to notice the contamination at a glance; change colar fish by specific ion

  12. Operation technology of air treatment system in nuclear facilities

    CERN Document Server

    Chun, Y B; Hwong, Y H; Lee, H K; Min, D K; Park, K J; Uom, S H; Yang, S Y

    2001-01-01

    Effective operation techniques were reviewed on the air treatment system to protect the personnel in nuclear facilities from the contamination of radio-active particles and to keep the environment clear. Nuclear air treatment system consisted of the ventilation and filtering system was characterized by some test. Measurement of air velocity of blowing/exhaust fan in the ventilation system, leak tests of HEPA filters in the filtering, and measurement of pressure difference between the areas defined by radiation level were conducted. The results acquired form the measurements were reflected directly for the operation of air treatment. In the abnormal state of virus parts of devices composted of the system, the repairing method, maintenance and performance test were also employed in operating effectively the air treatment system. These measuring results and techniques can be available to the operation of air treatment system of PIEF as well as the other nuclear facilities in KAERI.

  13. Mockup Small-Diameter Air Distribution System

    Energy Technology Data Exchange (ETDEWEB)

    A. Poerschke and A. Rudd

    2016-05-01

    This report investigates the feasibility of using a home-run manifold small-diameter duct system to provide space conditioning air to individual thermal zones in a low-load home. This compact layout allows duct systems to be brought easily within conditioned space via interior partition walls. Centrally locating the air hander unit in the house significantly reduces duct lengths. The plenum box is designed so that each connected duct receives an equal amount of airflow, regardless of the duct position on the box. Furthermore, within a reasonable set of length restrictions, each duct continues to receive similar airflow. The design method uses an additive approach to reach the total needed zonal airflow. Once the cubic feet per minute needed to satisfy the thermal load of a zone has been determined, the total number of duct runs to a zone can be calculated by dividing the required airflow by the standard airflow from each duct. The additive approach greatly simplifies the design effort and reduces the potential for duct design mistakes to be made. Measured results indicate that this plenum design can satisfy the heating load. However, the total airflow falls short of satisfying the cooling load in a hypothetical building. Static pressure inside the plenum box of 51.5 Pa limited the total airflow of the attached mini-split heat pump blower, thus limiting the total thermal capacity. Fan energy consumption is kept to 0.16 to 0.22 watt/CFM by using short duct runs and smooth duct material.

  14. Experimental Study of Air Distribution and Ventilation Effectiveness in a Room with a Combination of Different Mechanical Ventilation and Heating/Cooling Systems

    DEFF Research Database (Denmark)

    Olesen, Bjarne W.; Simone, Angela; Krajcik, Michal

    2011-01-01

    Mixing and displacement ventilation are common systems in commercial buildings, while mixing ventilation is used in residential buildings. Displacement ventilation provides fresh air to the occupied zone in a more efficient way than mixing ventilation but it is important to know how well it works...... with a floor system for heating or cooling. Can, for example, a floor heating system warm up the supply air too fast and destroy the displacement effect? Will floor cooling, combined with displacement ventilation, result in too high a vertical temperature difference and too low a temperature at feet level......? The required amount of ventilation depends on the ventilation effectiveness. In standards, the recommended values for ventilation effectiveness depend on the position of the supply and exhaust device and on the difference between supply and room air temperature. Among others, for warm air heating...

  15. The microbiological quality of air improves when using air conditioning systems in cars

    OpenAIRE

    Vonberg, Ralf-Peter; Gastmeier, Petra; Kenneweg, Bj?rn; Holdack-Janssen, Hinrich; Sohr, Dorit; Chaberny, Iris F

    2010-01-01

    Abstract Background Because of better comfort, air conditioning systems are a common feature in automobiles these days. However, its impact on the number of particles and microorganisms inside the vehicle - and by this its impact on the risk of an allergic reaction - is yet unknown. Methods Over a time period of 30 months, the quality of air was investigated in three different types of cars (VW Passat, VW Polo FSI, Seat Alhambra) that were all equipped with a automatic air conditioning system...

  16. A preliminary look at the impacts of warming on the federal Columbia River power system

    International Nuclear Information System (INIS)

    Stephan, N.

    2008-01-01

    Studies have indicated that the precipitation changes resulting from climatic warming are unlikely to be distinguishable from natural variability until late in the 21. century. This study presented scenarios and projected changes for the Federal Columbia River power system that used volume and runoff data in monthly time-steps. A streamflow model of data from the previous 44 years was also used. The region is currently meeting 50 per cent of its loads with clean hydro-generation, and is now examining ways of limiting greenhouse gas (GHG) emissions as electricity loads continue to grow. The impacts of climate change were compared with projected loads up to the year 2040. Flow targets for regional fish operations peak between April and July. Volume changes in water as a result of hydroelectricity projects in the region have also been simulated. Monitoring tools and meteorological data were presented as well as watershed run-off data from 1929 to 2008. Policies related to climate change continue to be challenged by both legal and political issues as well as a lack of strategic planning. It was concluded that accurate system modelling is needed to avoid the impacts of costly and un-informed decision-making processes. tabs., figs

  17. Six years of surface remote sensing of stratiform warm clouds in marine and continental air over Mace Head, Ireland

    Science.gov (United States)

    Preißler, Jana; Martucci, Giovanni; Saponaro, Giulia; Ovadnevaite, Jurgita; Vaishya, Aditya; Kolmonen, Pekka; Ceburnis, Darius; Sogacheva, Larisa; de Leeuw, Gerrit; O'Dowd, Colin

    2016-12-01

    A total of 118 stratiform water clouds were observed by ground-based remote sensing instruments at the Mace Head Atmospheric Research Station on the west coast of Ireland from 2009 to 2015. Microphysical and optical characteristics of these clouds were studied as well as the impact of aerosols on these properties. Microphysical and optical cloud properties were derived using the algorithm SYRSOC (SYnergistic Remote Sensing Of Clouds). Ground-based in situ measurements of aerosol concentrations and the transport path of air masses at cloud level were investigated as well. The cloud properties were studied in dependence of the prevailing air mass at cloud level and season. We found higher cloud droplet number concentrations (CDNC) and smaller effective radii (reff) with greater pollution. Median CDNC ranged from 60 cm-3 in marine air masses to 160 cm-3 in continental air. Median reff ranged from 8 μm in polluted conditions to 10 μm in marine air. Effective droplet size distributions were broader in marine than in continental cases. Cloud optical thickness (COT) and albedo were lower in cleaner air masses and higher in more polluted conditions, with medians ranging from 2.1 to 4.9 and 0.22 to 0.39, respectively. However, calculation of COT and albedo was strongly affected by liquid water path (LWP) and departure from adiabatic conditions. A comparison of SYRSOC results with MODIS (Moderate-Resolution Imaging Spectroradiometer) observations showed large differences for LWP and COT but good agreement for reff with a linear fit with slope near 1 and offset of -1 μm.

  18. An Air-conditioned Global Warming. The Description of Settings in Ian McEwan’s Solar

    Directory of Open Access Journals (Sweden)

    Elisa Bolchi

    2016-12-01

    Full Text Available The three main settings of McEwan’s Solar, a novel described as “the first great global-warming novel” (Walsh 2010 are significant: from London, to the Artic Pole, up to the desert in New Mexico, these places are all described through the interior monologue of the anti-hero Michael Beard, a character allegorical of humanity’s greed for selfish over-consumption. As Beard moves in the real environment only through the non-places of supermodernity (Augé, the paper ana¬lyses the descriptions of settings to underline how McEwan uses them to write about climate- change in a new “novelistic” way (McEwan.

  19. Indoor air quality environmental information handbook: Building system characteristics

    International Nuclear Information System (INIS)

    1987-01-01

    This manual, the third in a series, focuses on residential building system characteristics and their effects on indoor air quality. The manual addresses: residential indoor air pollutants by source, indoor concentrations, health effects, source control and mitigation techniques, standards and guidelines; building system characteristics of air exchange, pollutant source strength, residence volume, site characteristics, structural design, construction, and operation, infiltration and ventilation system, building occupancy; and monitoring methods

  20. 14 CFR 25.1103 - Induction system ducts and air duct systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction system ducts and air duct systems....1103 Induction system ducts and air duct systems. (a) Each induction system duct upstream of the first... auxiliary power unit bleed air duct systems, no hazard may result if a duct failure occurs at any point...

  1. Use of local convective and radiant cooling at warm environment: effect on thermal comfort and perceived air quality

    DEFF Research Database (Denmark)

    Melikov, Arsen Krikor; Duszyk, Marcin; Krejcirikova, Barbora

    2012-01-01

    compared to without cooling. The acceptability of the thermal environment was similar for all cooling devices. The acceptability of air movement and PAQ increased when the local cooling methods were used. The best results were achieved with personalized ventilation and cooling fan. The improvement in PAQ...

  2. Improving compressed air system performance: A sourcebook for industry

    OpenAIRE

    Mckane, Aimee T.

    2003-01-01

    Compressed air is used widely throughout industry and is often considered the "fourth utility" at many facilities. Almost every industrial plant, from a small machine shop to an immense pulp and paper mill, has some type of compressed air system. In many cases, the compressed air system is so vital that the facility cannot operate without it. Plant air compressor systems can vary in size from a small unit of 5 horsepower (hp) to huge systems with more than 50,000 hp. In many industrial facili...

  3. INTEGRATED SAFETY MANAGEMENT SYSTEM IN AIR TRAFFIC SERVICES

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2014-06-01

    Full Text Available The article deals with the analysis of the researches conducted in the field of safety management systems.Safety management system framework, methods and tools for safety analysis in Air Traffic Control have been reviewed.Principles of development of Integrated safety management system in Air Traffic Services have been proposed.

  4. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given ...

  5. Diffuse Ceiling Inlet Systems and the Room Air Distribution

    DEFF Research Database (Denmark)

    Nielsen, Peter V.; Jensen, Rasmus Lund; Rong, Li

    2010-01-01

    A diffuse ceiling inlet system is an air distribution system which is supplying the air through the whole ceiling. The system can remove a large heat load without creating draught in the room. The paper describes measurements in the case of both cooling and heating, and CFD predictions are given...

  6. A RADIANT AIR-CONDITIONING SYSTEM USING SOLAR-DRIVEN

    Directory of Open Access Journals (Sweden)

    S. A. ABDALLA

    2006-12-01

    Full Text Available Every air-conditioning system needs some fresh air to provide adequate ventilation air required to remove moisture, gases like ammonia and hydrogen sulphide, disease organisms, and heat from occupied spaces. However, natural ventilation is difficult to control because urban areas outside air is often polluted and cannot be supplied to inner spaces before being filtered. Besides the high electrical demand of refrigerant compression units used by most air-conditioning systems, and fans used to transport the cool air through the thermal distribution system draw a significant amount of electrical energy in comparison with electrical energy used by the building thermal conditioning systems. Part of this electricity heats the cooled air; thereby add to the internal thermal cooling peak load. In addition, refrigerant compression has both direct and indirect negative effects on the environment on both local and global scales. In seeking for innovative air-conditioning systems that maintain and improve indoor air quality under potentially more demanding performance criteria without increasing environmental impact, this paper presents radiant air-conditioning system which uses a solar-driven liquid desiccant evaporative cooler. The paper describes the proposed solar-driven liquid desiccant evaporative cooling system and the method used for investigating its performance in providing cold water for a radiant air-conditioning system in Khartoum (Central Sudan. The results of the investigation show that the system can operate in humid as well as dry climates and that employing such a system reduces air-conditioning peak electrical demands as compared to vapour compression systems.

  7. Mold contamination of automobile air conditioner systems.

    Science.gov (United States)

    Kumar, P; Lopez, M; Fan, W; Cambre, K; Elston, R C

    1990-02-01

    Eight cars belonging to patients who were found to have exacerbation of allergic rhinitis and bronchial asthma after turning on the air conditioner in their cars were examined. Mold concentrations inside the passenger compartment with the a/c turned off and at different climate control settings were lower than concentrations in the outside air. After turning on the air conditioner to "Max", cultures obtained at various intervals revealed that mold concentrations decreased significantly with time. Furthermore, placement of a filter at the portal of entry of outside air significantly reduced the mold concentration in the passenger compartment.

  8. GLOBAL WARMING, CLIMATE CHANGE AND TOURISM: A REVIEW OF LITERATURE

    OpenAIRE

    Ramasamy, Rajesh; Swamy, Anjaneya

    2015-01-01

    Global warming, climate change and tourism of late, have taken the centre stage of academic research. A raging debate is on apart from the popular writings and research articles published on the theme. According to the Intergovernmental Panel on Climate Change “Warming of the climate system is unequivocal as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice since the mid 20th century”. This conceptual paper discussed...

  9. Contributions of air pollution and climate warming to tufa wetland degradation in Jiuzhaigou National Nature Reserve, eastern rim of the Qinghai-Tibetan Plateau, China

    Science.gov (United States)

    Qiao, X.; Tang, Y.

    2017-12-01

    Massive deposition of calcium carbonate in ambient temperature waters forms magnificent tufa wetlands, many of which are designated as protected areas and are popular tourist destinations. There is a tufa wetland belt along the Eastern Rim of the Qinghai-Tibetan Plateau (ERQTP), and many of them are experiencing degradation, such as nutrient enrichment and tufa degradation. Meanwhile, there is also an air pollution belt in the ERQTP. This study was made to understand the correlation of tufa wetland degradation with climate change and air pollution for Jiuzhaigou National Nature Reserve (hereafter Jiuzhaigou). Atmospheric changes were first studied. The results show that annual mean air temperature increased by 1.2oC from 1951 to 2014. Anthropogenic emissions contributed to over 90% annual wet deposition fluxes of reactive sulfur and nitrogen and caused acid rain (pHair pollutants. Then, the impacts of air pollution and climate warming on tufa wetlands were further investigated. We found that precipitation was calcite-unsaturated so it could dissolve exposed tufa and considerably reduce tufa deposition rate and even cause tufa dissolution in shallow waters. These effects enhanced as precipitation pH decreased. Annual volume-weighted mean concentration of reactive nitrogen in wet deposition and runoff were 26.1 and 14.8 µmol L-1, respectively, both exceeding China's national standard of total nitrogen in runoff for nature reserves (14.3 µmol L-1) and this suggested a nitrogen fertilization effect of wet deposition on green algae. As water temperature is the limiting factor of algal growth in Jiuzhaigou and temperature in the top layer (0-5 cm) of runoff (with a depthair pollutants have contributed to tufa wetland degradation in Jiuzhaigou, but in order to better quantify the contributions, further studies are needed, as many other anthropogenic and natural processes also influence tufa wetland evolution.

  10. Infrared Heater Arrays (T-FACE) for Warming Open-Field Plots of Wheat

    Science.gov (United States)

    In order to study the likely effects of global warming on field-grown crops, a method is needed to warm open-field plots and create an environment like that expected in the future. One such T-FACE (Temperature Free-Air Controlled Enhancement) system that shows promise is to deploy hexagonal arrays o...

  11. Air quality information system for Gauteng

    CSIR Research Space (South Africa)

    Nkuna, J

    2006-10-01

    Full Text Available Air pollution is one of the challenges for sustainable development (Johannesburg being rated fifth worst in the world) One of nine agreed strategies: “Improvement of Air Quality (reduce emissions from vehicles, industry, mines/tailing dams...

  12. Design of a Hydraulic Motor System Driven by Compressed Air

    Directory of Open Access Journals (Sweden)

    Jyun-Jhe Yu

    2013-06-01

    Full Text Available This paper presents the design of a highly efficient pneumatic motor system. The air engine is currently the most generally used device to convert potential energy of compressed air into mechanical energy. However, the efficiency of the air engines is too low to provide sufficient operating range for the vehicle. In this study, the energy contained in compressed air/pressurized hydraulic oil is transformed by a hydraulic motor to mechanical energy to enhance the efficiency of using air power. To evaluate the theoretical efficiency, the principle of balance of energy is applied. The theoretical efficiency of converting air into hydraulic energy is found to be a function of pressure; thus, the maximum converting efficiency can be determined. To confirm the theoretical evaluation, a prototype of the pneumatic hydraulic system is built. The experiment verifies that the theoretical evaluation of the system efficiency is reasonable, and that the layout of the system is determined by the results of theoretical evaluation.

  13. Systems optimisation of an active thermal management system during engine warm-up

    OpenAIRE

    Burke, Richard D.; Lewis, Andrew J.; Akehurst, Sam; Brace, Chris J.; Pegg, Ian; Stark, Roland

    2012-01-01

    Active thermal management systems offer a potential for small improvements in fuel consumption that will contribute to upcoming legislation on carbon dioxide emissions. These systems offer new degrees of freedom for engine calibration; however, their full potential will only be exploited if a systems approach to their calibration is adopted, in conjunction with other engine controls. In this work, a design-of-experiments approach is extended to allow its application to transient drive cycles ...

  14. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Somerville, MA (United States); Bergey, Daniel [Building Science Corporation, Somerville, MA (United States)

    2014-02-01

    In this project, Building America research team Building Science Corporation tested the effectiveness of ventilation systems at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. This was because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four system factor categories: balance, distribution, outside air source, and recirculation filtration. Recommended system factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  15. Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bergey, Daniel [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2014-02-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow. Cumulative particle counts for six particle sizes, and formaldehyde and other Top 20 VOC concentrations were measured in multiple zones. The testing showed that single-point exhaust ventilation was inferior as a whole-house ventilation strategy. It was inferior because the source of outside air was not direct from outside, the ventilation air was not distributed, and no provision existed for air filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs. System improvement percentages were estimated based on four System Factor Categories: Balance, Distribution, Outside Air Source, and Recirculation Filtration. Recommended System Factors could be applied to reduce ventilation fan airflow rates relative to ASHRAE Standard 62.2 to save energy and reduce moisture control risk in humid climates. HVAC energy savings were predicted to be 8-10%, or $50-$75/year.

  16. Evaluation of an improved air distribution system for aircraft cabin

    DEFF Research Database (Denmark)

    Pang, Liping; Xu, Jie; Fang, Lei

    2013-01-01

    of contaminated air above the head of the passengers. The improved pattern may overcome the above challenges quite well while also delivering good ventilation performance. The modified Personal Exposure Effectiveness (PEE) was measured to compare their performances with regard to inhaled air quality. The measured......An improved air distribution system for aircraft cabin was proposed in this paper. Personalized outlets were introduced and placed at the bottom of the baggage hold. Its ratio of fresh air to recirculation air and the conditioned temperature of different types of inlets were also designed carefully...... to meet the goals of high air quality, thermal comfort and energy saving. Some experiments were conducted to evaluate and compare its performances with two other systems. First the Flow Visualization with Green Laser (FVGL) technology was used to analyze the air flow. The top-in-side bottom-out pattern...

  17. Annual performance of building-integrated photovoltaic/water-heating system for warm climate application

    International Nuclear Information System (INIS)

    Chow, T.T.; Chan, A.L.S.; Fong, K.F.; Lin, Z.; He, W.; Ji, J.

    2009-01-01

    A building-integrated photovoltaic/water-heating (BiPVW) system is able to generate higher energy output per unit collector area than the conventional solar systems. Through computer simulation with energy models developed for this integrative solar system in Hong Kong, the results showed that the photovoltaic/water-heating (PVW) system has economic advantages over the conventional photovoltaic (PV) installation. The system thermal performance under natural water circulation was found better than the pump-circulation mode. For a specific BiPVW system at a vertical wall of a fully air-conditioned building and with collectors equipped with flat-box-type thermal absorber and polycrystalline silicon cells, the year-round thermal and cell conversion efficiencies were found respectively 37.5% and 9.39% under typical Hong Kong weather conditions. The overall heat transmission through the PVW wall is reduced to 38% of the normal building facade. When serving as a water pre-heating system, the economical payback period was estimated around 14 years. This greatly enhances the PV market opportunities. (author)

  18. Air Conditioning Systems from a 2nd Law Perspective

    Directory of Open Access Journals (Sweden)

    Luigi Marletta

    2010-04-01

    Full Text Available In this paper exergy analysis is used to assess the performance of the three most common air conditioning plant schemes: all-air, dual-duct and fan-coil systems. The results are presented in terms of flow diagrams to provide a clear picture of the exergy flow across the systems. The most relevant outcomes are that the air cooling and dehumidification is the process most responsible for the exergy loss and that the exergy efficiency of the overall systems is rather low; thus the quest for more appropriate technologies. Solar-assisted air-conditioning is also discussed, outlining the possibilities and the constraints.

  19. The microbiological quality of air improves when using air conditioning systems in cars.

    Science.gov (United States)

    Vonberg, Ralf-Peter; Gastmeier, Petra; Kenneweg, Björn; Holdack-Janssen, Hinrich; Sohr, Dorit; Chaberny, Iris F

    2010-06-01

    Because of better comfort, air conditioning systems are a common feature in automobiles these days. However, its impact on the number of particles and microorganisms inside the vehicle--and by this its impact on the risk of an allergic reaction--is yet unknown. Over a time period of 30 months, the quality of air was investigated in three different types of cars (VW Passat, VW Polo FSI, Seat Alhambra) that were all equipped with a automatic air conditioning system. Operation modes using fresh air from outside the car as well as circulating air from inside the car were examined. The total number of microorganisms and the number of mold spores were measured by impaction in a high flow air sampler. Particles of 0.5 to 5.0 microm diameter were counted by a laser particle counter device. Overall 32 occasions of sampling were performed. The concentration of microorganisms outside the cars was always higher than it was inside the cars. Few minutes after starting the air conditioning system the total number of microorganisms was reduced by 81.7%, the number of mold spores was reduced by 83.3%, and the number of particles was reduced by 87.8%. There were no significant differences neither between the types of cars nor between the types of operation mode of the air conditioning system (fresh air vs. circulating air). All parameters that were looked for in this study improved during utilization of the car's air conditioning system. We believe that the risk of an allergic reaction will be reduced during use also. Nevertheless, we recommend regular maintenance of the system and replacement of older filters after defined changing intervals.

  20. The microbiological quality of air improves when using air conditioning systems in cars

    Directory of Open Access Journals (Sweden)

    Holdack-Janssen Hinrich

    2010-06-01

    Full Text Available Abstract Background Because of better comfort, air conditioning systems are a common feature in automobiles these days. However, its impact on the number of particles and microorganisms inside the vehicle - and by this its impact on the risk of an allergic reaction - is yet unknown. Methods Over a time period of 30 months, the quality of air was investigated in three different types of cars (VW Passat, VW Polo FSI, Seat Alhambra that were all equipped with a automatic air conditioning system. Operation modes using fresh air from outside the car as well as circulating air from inside the car were examined. The total number of microorganisms and the number of mold spores were measured by impaction in a high flow air sampler. Particles of 0.5 to 5.0 μm diameter were counted by a laser particle counter device. Results Overall 32 occasions of sampling were performed. The concentration of microorganisms outside the cars was always higher than it was inside the cars. Few minutes after starting the air conditioning system the total number of microorganisms was reduced by 81.7%, the number of mold spores was reduced by 83.3%, and the number of particles was reduced by 87.8%. There were no significant differences neither between the types of cars nor between the types of operation mode of the air conditioning system (fresh air vs. circulating air. All parameters that were looked for in this study improved during utilization of the car's air conditioning system. Conclusions We believe that the risk of an allergic reaction will be reduced during use also. Nevertheless, we recommend regular maintenance of the system and replacement of older filters after defined changing intervals.

  1. Air liquide's space pulse tube cryocooler systems

    Science.gov (United States)

    Trollier, T.; Tanchon, J.; Buquet, J.; Ravex, A.

    2017-11-01

    Thanks to important development efforts completed with ESA funding, Air Liquide Advanced Technology Division (AL/DTA), is now in position to propose two Pulse Tube cooler systems in the 40-80K temperature range for coming Earth Observation missions such as Meteosat Third Generation (MTG), SIFTI, etc… The Miniature Pulse Tube Cooler (MPTC) is lifting up to 2.47W@80K with 50W compressor input power and 10°C rejection temperature. The weight is 2.8 kg. The Large Pulse Tube Cooler (LPTC) is providing 2.3W@50K for 160W input power and 10°C rejection temperature. This product is weighing 5.1 kg. The two pulse tube coolers thermo-mechanical units are qualified against environmental constraints as per ECSS-E-30. They are both using dual opposed pistons flexure bearing compressor with moving magnet linear motors in order to ensure very high lifetime. The associated Cooler Drive Electronics is also an important aspect specifically regarding the active control of the cooler thermo-mechanical unit during the launch phase and the active reduction of the vibrations induced by the compressor (partly supported by the French Agency CNES). This paper details the presentation of the two Pulse Tube Coolers together with the Cooler Drive Electronics aspects.

  2. Use of germicidal ultraviolet radiations in air conditionning systems

    Energy Technology Data Exchange (ETDEWEB)

    Hillebrecht, J.; Kohler, N.

    1989-02-01

    Hygienical risks appear in air conditionning plants in humid parts, at the interface between clean and unclean zones and in heat recovery systems. Ultraviolet radiations with a wavelength of 254 etam disactivate germs in a purely physical way. They can be successfully used in air conditionning systems: in air ducts, over doors and in transition spaces, in humidifiers and cooling towers and as direct irradiation in clean rooms. The efficiency can be proven by calculations or experimentally.

  3. An Investigation about using Nanorefrigerants in Air Conditioning Systems According to the Theoretical, CFD and Experimental Review of the Recent Literature

    Directory of Open Access Journals (Sweden)

    Farshad Panahizadeh

    2016-10-01

    Full Text Available Greenhouse gases (GHG causing global warming and climate change. In the year 2014, 32.3 billion tones CO2 emitted to the atmosphere as the most important greenhouse gas. According to the statistics, a significant portion of this amount is related to electricity demand of air conditioning systems, for producing a one ton of refrigeration in HVAC air cooled or water cooled systems respectively 1026 and 764 grams GHG emitted in the atmosphere. Therefore, air conditioning systems have an important role in the global warming and climate change. By increasing the COP of air conditioning systems the electricity demand of them reduced. One strategy for increasing the COP of air conditioning systems is using nanorefrigerants. In the present study, a comprehensive information is given regarding to use nanorefrigerants in air conditioning systems according to the theoretical, CFD and experimental review of the recent literature. This paper gives assistance to designers of air conditioning systems in their future efforts for selecting refrigerant for their systems

  4. Comparison of desiccant air conditioning systems with different indirect evaporative air coolers

    International Nuclear Information System (INIS)

    Pandelidis, Demis; Anisimov, Sergey; Worek, William M.; Drąg, Paweł

    2016-01-01

    Highlights: • A numerical study of desiccant air conditioning systems is presented. • The ε-NTU model is used for the analysis. • Different arrangements of the desiccant systems were compared. • The systems were compared under different operating conditions. - Abstract: This paper presents a numerical analysis of three desiccant air-conditioning systems equipped with different indirect evaporative air coolers: (1) the cross-flow Maisotsenko cycle heat and mass exchanger (HMX), (2) the regenerative counter-flow Maisotsenko cycle heat and mass exchanger and (3) the standard cross-flow evaporative air cooler. To analyze the desiccant wheel and the indirect evaporative air coolers, the modified ε-NTU-model was used. The simulations were performed under assumption that the desiccant wheel is regenerated with air heated to relatively low temperature values (50–60 °C), which can be produced with solar panels in typical moderate climatic conditions. It was established that the main advantage of the presented solutions is that they can provide comfort conditions even with less effective dehumidification. The different systems were compared under variable selected operational factors (i.e. inlet air temperature, humidity and regeneration air temperature). The analysis allowed establishing the advantages and disadvantages of presented solutions and allowed estimating their application potential.

  5. Variations of polycyclic aromatic hydrocarbons in ambient air during haze and non-haze episodes in warm seasons in Hangzhou, China.

    Science.gov (United States)

    Lu, Hao; Wang, Shengsheng; Wu, Zuliang; Yao, Shuiliang; Han, Jingyi; Tang, Xiujuan; Jiang, Boqiong

    2017-01-01

    To investigate the characteristics of polycyclic aromatic hydrocarbons (PAHs) during haze episodes in warm seasons, daily PM 2.5 and gaseous samples were collected from March to September 2015 in Hangzhou, China. Daily samples were further divided into four groups by the definition of haze according to visibility and relative humidity (RH), including non-haze (visibility, >10 km), light haze (visibility, 8-10 km, RH <90 %), medium haze (visibility, 5-8 km, RH <90 %), and heavy haze (visibility, <5 km, RH <90 %). Significantly higher concentrations of PM 2.5 -bound PAHs were found in haze days, but the mean PM 2.5 -bound PAH concentrations obviously decreased with the aggravation of haze pollution from light to heavy. The gas/particle partitioning coefficients of PAHs decreased from light-haze to heavy-haze episodes, which indicated that PM 2.5 -bound PAHs were restricted to adhere to the particulate phase with the aggravation of haze pollution. Absorption was considered the main mechanism of gas/particle partitioning of PAHs from gaseous to particulate phase. Analysis of air mass transport indicated that the PM 2.5 -bound PAH pollution in haze days was largely from regional sources but also significantly affected by long-range air mass transport. The inhalation cancer risk associated with PAHs exceeded the acceptable risk level markedly in both haze and non-haze days.

  6. Identifying and assessing the role of warm air advection (Atmospheric Rivers) along the west coast of Greenland comparing various reanalyses for the period 2000-2012

    Science.gov (United States)

    Neff, William; Shupe, Matthew; Compo, Gilbert P.

    2017-04-01

    Neff et al. (2014) examined the 2012 summer Greenland melt episode and compared it to the last episode in 1889 using the Twentieth Century Reanalysis (20CR, Compo et al. 2011). A key factor in both 2012 and 1889 was the presence of an Atmospheric River (AR) that transported warm air over the Atlantic Ocean and thence to the west coast of Greenland. ARs are thin filaments of high-moisture air occurring at frontal boundaries and represent an efficient poleward transport mechanism for warm moist air (Newell et al. 1992) to the Arctic (Bonne et al. 2015; Neff et al. 2014) and the Antarctic (Gorodetskaya et al. 2014). The cases in 1889 and 2012 share a similar synoptic situation with lows just south and/or west of Baffin Island and highs to the southeast of Greenland. Although the details in the position of the moisture plumes are different, they both produce an anomaly in integrated water vapor (IWV) just off the southwest coast of Greenland suggesting this location as a key diagnostic location for potential AR impact on west Greenland. As part of a long-term goal to assess the frequency of such events that affect the surface energy budget of Greenland back to 1871 using the 20CR, we have compared in more detail transport signatures using 20CR, ERA-I, and NCEP-NCAR reanalyses for the period 2000-2012. In particular, we used reanalysis data at 50oW, 60oN, which lies just off the southwest coast of Greenland. These data included wind speed and direction, integrated precipitable water vapor (IWV), and specific humidity (q) at 850 hPa (which is a nominal height for the southerly coastal jet identified in previous AR events (Neff et al. 2014).) We found substantial agreement in the various reanalyses in terms of wind direction and speed distributions. We found IWV spatial distributions during southerly wind speed and IWV maxima that range from "blobs" to well-organized transport events. Using compositing techniques we also have examined the subsequence evolution of

  7. Air

    Science.gov (United States)

    ... gov/ Home The environment and your health Air Air While we don’t often think about the ... do to protect yourself from dirty air . Indoor air pollution and outdoor air pollution Air can be ...

  8. 14 CFR 33.66 - Bleed air system.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Bleed air system. 33.66 Section 33.66 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: AIRCRAFT ENGINES Design and Construction; Turbine Aircraft Engines § 33.66 Bleed air system. The...

  9. Novel MAV Air Data System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — The development of Micro Air Vehicles (MAVs) has received considerable attention in recent years for both military and civilian uses. MAVs typically suffer from...

  10. Modeling activities in air traffic control systems: antecedents and consequences of a mid-air collision.

    Science.gov (United States)

    de Carvalho, Paulo Victor R; Ferreira, Bemildo

    2012-01-01

    In this article we present a model of some functions and activities of the Brazilian Air traffic Control System (ATS) in the period in which occurred a mid-air collision between flight GLO1907, a commercial aircraft Boeing 737-800, and flight N600XL, an executive jet EMBRAER E-145, to investigate key resilience characteristics of the ATM. Modeling in some detail activities during the collision and related them to overall behavior and antecedents that stress the organization uncover some drift into failure mechanisms that erode safety defenses provided by the Air Navigation Service Provider (ANSP), enabling a mid-air collision to be happen.

  11. Acceptance Test Report for 241-U compressed air system

    International Nuclear Information System (INIS)

    Freeman, R.D.

    1994-01-01

    This Acceptance Test Report (ATR) documents the results of acceptance testing of a newly upgraded compressed air system at 241-U Farm. The system was installed and the test successfully performed under work package 2W-92-01027

  12. Validation and development of existing and new RAOB-based warm-season convective wind forecasting tools for Cape Canaveral Air Force Station and Kennedy Space Center

    Science.gov (United States)

    McCue, Mitchell Hollis

    Using a 15-year (1995 to 2009) climatology of 1500 UTC warm-season (May through September) rawinsonde observation (RAOB) data from the Cape Canaveral Air Force Station (CCAFS) Skid Strip (KXMR) and 5 minute wind data from 36 wind towers on CCAFS and Kennedy Space Center (KSC), several convective wind forecasting techniques currently employed by the 45th Weather Squadron (45 WS) were evaluated. Present forecasting methods under evaluation include examining the vertical equivalent potential temperature (theta e) profile, vertical profiles of wind spend and direction, and several wet downburst forecasting indices. Although previous research found that currently used wet downburst forecasting methods showed little promise for forecasting convective winds, it was carried out with a very small sample, limiting the reliability of the results. Evaluation versus a larger 15-year dataset was performed to truly assess the forecasting utility of these methods in the central Florida warm-season convective environment. In addition, several new predictive analytic based forecast methods for predicting the occurrence of warm-season convection and its associated wind gusts were developed and validated. This research was performed in order to help the 45 WS better forecast not only which days are more likely to produce convective wind gusts, but also to better predict which days are more likely to yield warning criteria wind events of 35 knots or greater, should convection be forecasted. Convective wind forecasting is a very challenging problem that requires new statistically based modeling techniques since conventional meteorologically based methods do not perform well. New predictive analytic based forecasting methods were constructed using R statistical software and incorporate several techniques including multiple linear regression, logistic regression, multinomial logistic regression, classification and regression trees (CART), and ensemble CART using bootstrapping. All of

  13. Agave as a model CAM crop system for a warming and drying world.

    Science.gov (United States)

    Stewart, J Ryan

    2015-01-01

    As climate change leads to drier and warmer conditions in semi-arid regions, growing resource-intensive C3 and C4 crops will become more challenging. Such crops will be subjected to increased frequency and intensity of drought and heat stress. However, agaves, even more than pineapple (Ananas comosus) and prickly pear (Opuntia ficus-indica and related species), typify highly productive plants that will respond favorably to global warming, both in natural and cultivated settings. With nearly 200 species spread throughout the U.S., Mexico, and Central America, agaves have evolved traits, including crassulacean acid metabolism (CAM), that allow them to survive extreme heat and drought. Agaves have been used as sources of food, beverage, and fiber by societies for hundreds of years. The varied uses of Agave, combined with its unique adaptations to environmental stress, warrant its consideration as a model CAM crop. Besides the damaging cycles of surplus and shortage that have long beset the tequila industry, the relatively long maturation cycle of Agave, its monocarpic flowering habit, and unique morphology comprise the biggest barriers to its widespread use as a crop suitable for mechanized production. Despite these challenges, agaves exhibit potential as crops since they can be grown on marginal lands, but with more resource input than is widely assumed. If these constraints can be reconciled, Agave shows considerable promise as an alternative source for food, alternative sweeteners, and even bioenergy. And despite the many unknowns regarding agaves, they provide a means to resolve disparities in resource availability and needs between natural and human systems in semi-arid regions.

  14. Agave as a model CAM crop system for a warming and drying world

    Directory of Open Access Journals (Sweden)

    J. Ryan eStewart

    2015-09-01

    Full Text Available As climate change leads to drier and warmer conditions in semi-arid regions, growing resource-intensive C3 and C4 crops will become more challenging. Such crops will be subjected to increased frequency and intensity of drought and heat stress. However, agaves, even more than pineapple (Ananas comosus and prickly pear (Opuntia ficus-indica and related species, typify highly productive plants that will respond favorably to global warming, both in natural and cultivated settings. With nearly 200 species spread throughout the U.S., Mexico, and Central America, agaves have evolved traits, including crassulacean acid metabolism (CAM, that allow them to survive extreme heat and drought. Agaves have been used as sources of food, beverage, and fiber by societies for hundreds of years. The varied uses of Agave, combined with its unique adaptations to environmental stress, warrant its consideration as a model CAM crop. Besides the damaging cycles of surplus and shortage that have long beset the tequila industry, the relatively long maturation cycle of Agave, its monocarpic flowering habit, and unique morphology comprise the biggest barriers to its widespread use as a crop suitable for mechanized production. Despite these challenges, agaves exhibit potential as crops since they can be grown on marginal lands, but with more resource input than is widely assumed. If these constraints can be reconciled, Agave shows considerable promise as an alternative source for food, alternative sweeteners, and even bioenergy. And despite the many unknowns regarding agaves, they provide a means to resolve disparities between natural and human systems in semi-arid regions.

  15. The air pollution index system in Hong Kong

    Energy Technology Data Exchange (ETDEWEB)

    Lee, F.Y.P.; Gervat, G.P. [Hong Kong Government, Wanchai (Hong Kong). Environmental Protection Dept.

    1995-12-31

    The Hong Kong Environmental Protection Department (EPD) is currently operating an air quality monitoring network in the territory. There are nine monitoring stations, each with air quality monitoring equipment, meteorological instruments and a data logger. Five minute averaged data are transmitted through telephone lines to the central computer at the EPD Air Laboratory and are also stored in the data logger on site, as backup. At present, the EPD releases its air quality measurements to the public via monthly and special press releases, and annual reports. However, as public awareness of air pollution problems has increased, there has been an urgent need for timely and simpler information about air pollution levels. The development and operation of an Air Pollution Index (API) system has addressed that need. This presentation discusses the API computation, the information and advice released to the general public and how they can access the API information. Some API results are also presented. (author)

  16. Solar warming systems of water installed in Colombia. Photovoltaic solar systems installed in the Country

    International Nuclear Information System (INIS)

    Rodriguez P, F.

    1995-01-01

    Between the systems that operate as of solar energy, the solar collectors to heat water have had wide use and application in the Country. Basically, a solar collector is constituted by: Box, thermal insulator, ducts and transparent roof. Generally, the used materials are the following: As thermal insulator: Polyurethane or glass fiber; as absorbent plate: Copper or aluminum, painting in dull black or selective surfaces; for the ducts: Generally it is used copper pipeline; and for the cover: Common glass or temperate glass

  17. Predicting interactions among fishing, ocean warming, and ocean acidification in a marine system with whole-ecosystem models.

    Science.gov (United States)

    Griffith, Gary P; Fulton, Elizabeth A; Gorton, Rebecca; Richardson, Anthony J

    2012-12-01

    An important challenge for conservation is a quantitative understanding of how multiple human stressors will interact to mitigate or exacerbate global environmental change at a community or ecosystem level. We explored the interaction effects of fishing, ocean warming, and ocean acidification over time on 60 functional groups of species in the southeastern Australian marine ecosystem. We tracked changes in relative biomass within a coupled dynamic whole-ecosystem modeling framework that included the biophysical system, human effects, socioeconomics, and management evaluation. We estimated the individual, additive, and interactive effects on the ecosystem and for five community groups (top predators, fishes, benthic invertebrates, plankton, and primary producers). We calculated the size and direction of interaction effects with an additive null model and interpreted results as synergistic (amplified stress), additive (no additional stress), or antagonistic (reduced stress). Individually, only ocean acidification had a negative effect on total biomass. Fishing and ocean warming and ocean warming with ocean acidification had an additive effect on biomass. Adding fishing to ocean warming and ocean acidification significantly changed the direction and magnitude of the interaction effect to a synergistic response on biomass. The interaction effect depended on the response level examined (ecosystem vs. community). For communities, the size, direction, and type of interaction effect varied depending on the combination of stressors. Top predator and fish biomass had a synergistic response to the interaction of all three stressors, whereas biomass of benthic invertebrates responded antagonistically. With our approach, we were able to identify the regional effects of fishing on the size and direction of the interacting effects of ocean warming and ocean acidification. ©2012 Society for Conservation Biology.

  18. Impact of Organic Amendments on Global Warming Potential of Diversified Tropical Rice Rotation Systems

    Science.gov (United States)

    Janz, B.; Weller, S.; Kraus, D.; Wassmann, R.; Butterbach-Bahl, K.; Ralf, K.

    2017-12-01

    Paddy rice cultivation is increasingly challenged by irrigation water scarcity, which is forcing farmers to change traditional rice cultivation from flooded double-rice systems to the introduction of well-aerated upland crops during dry season. Emissions of methane (CH4) are expected to decrease, while there is a risk of increasing emissions of nitrous oxide (N2O) and decreasing soil organic carbon (SOC) stocks through volatilization in the form of carbon dioxide (CO2). We present a unique dataset of long-term continuous greenhouse gas emission measurements (CH4 and N2O) in the Philippines to assess global warming potentials (GWP) of diversified rice crop rotations including different field management practices such as straw residue application and legume intercropping. Since 2012, more than four years of CH4 and N2O emissions in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) during dry season have been collected. Introduction of upland crops reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Although dry season N2O emissions increased twice- to threefold in the diversified systems, the strong reduction of CH4 led to a significantly lower annual GWP (CH4 + N2O) as compared to the traditional R-R system. Diversified crop management practices were first implemented during land-preparation for dry season 2015 where i) 6 t/ha rice straw was returned to the field and ii) mungbean was grown as a cover-crop between dry and wet season in addition to rice straw application. The input of organic material (straw and mungbean) led to higher substrate availability for methanogens during the following season. Therefore, GWP was 9-39% higher following straw incorporation than the control treatment. This increase was mainly driven by additional CH4 emissions. Even more, mungbean intercropping further increased GWPs, whereby the increment was highest in R-R rotation (88%) and lowest in R

  19. Utilization of Solar Energy for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Sutikno Juwari Purwo

    2018-01-01

    Full Text Available The purposes of this research are to do a system simulation of air conditioning utilizing solar energy with single effect absorption refrigeration method, analyze the coefficient of performance (COP for each absorbent-refrigerant variable and compare the effectivity of every absorbent-refrigerant variable used. COP is a constant that denotes the effeciency of a refrigeration system, that is ratio of work or useful output to the amount of work or energy input. The higher the number of COP, the more efficient the system is. Absorbent-refrigerant (working fluids variables used in this research depend on its chemical and thermodynamics properties. Steps in this research are including data collection and tabulation from literature and do a simulation of air conditioning system both commercial air conditioning system (using electrical energy and solar energy air conditioning system with Aspen Plus software. Next, run the simulation for each working fluid variables used and calculate the COP for each variable. Subsequently, analyze and compare the effectivity of all variables used from COP value and economical point of view with commercial air conditioning system. From the result of the simulation, can be concluded that solar air conditioning can achieve 98,85 % of energy savings than commercial air conditioning. Furthermore, from the calculation of COP, the highest COP value is achieved by solar conditioning system with LiNO3-NH3 as working fluid where 55% of the composition is the refrigerant and 45% of absorbent.

  20. Position paper -- Tank ventilation system design air flow rates

    International Nuclear Information System (INIS)

    Goolsby, G.K.

    1995-01-01

    The purpose of this paper is to document a project position on required ventilation system design air flow rates for the waste storage tanks currently being designed by project W-236A, the Multi-Function Waste Tank Facility (MWTF). The Title 1 design primary tank heat removal system consists of two systems: a primary tank vapor space ventilation system; and an annulus ventilation system. At the conclusion of Title 1 design, air flow rates for the primary and annulus ventilation systems were 960 scfm and 4,400 scfm, respectively, per tank. These design flow rates were capable of removing 1,250,000 Btu/hr from each tank. However, recently completed and ongoing studies have resulted in a design change to reduce the extreme case heat load to 700,000 Btu/hr. This revision of the extreme case heat load, coupled with results of scale model evaporative testing performed by WHC Thermal Hydraulics, allow for a reduction of the design air flow rates for both primary and annulus ventilation systems. Based on the preceding discussion, ICF Kaiser Hanford Co. concludes that the design should incorporate the following design air flow rates: Primary ventilation system--500 scfm maximum and Annulus ventilation system--1,100 scfm maximum. In addition, the minimum air flow rates in the primary and annulus ventilation systems will be investigated during Title 2 design. The results of the Title 2 investigation will determine the range of available temperature control using variable air flows to both ventilation systems

  1. Experiments with duckweed-moth systems suggest global warming may reduce rather than promote herbivory

    NARCIS (Netherlands)

    Heide, van Tj.; Roijackers, R.M.M.; Peeters, E.T.H.M.; Nes, van E.H.

    2006-01-01

    1. Wilf & Labandeira (1999)suggested that increased temperatures because of global warming will cause an increase in herbivory by insects. This conclusion was based on the supposed effect of temperature on herbivores but did not consider an effect of temperature on plant growth. 2. We studied

  2. Effects of warming yang and invigorating qi prescription on renin-angiotensin-aldosterone system in rats with heart failure after myocardial infarction

    Directory of Open Access Journals (Sweden)

    Lihua HAN

    Full Text Available Abstract This study investigated the effects of warming yang and invigorating qi prescription on renin-angiotensin-aldosterone system (RAAS in rats with heart failure after myocardial infarction. 126 rats were randomly divided into model group, sham operation, warming yang, invigorating qi, warming yang+invigorating qi, digoxin and captopril group for respective treatment. After intervention for 6, 8 and 10 weeks, the left ventricular ejection fraction (LVEF was calculated, and the plasma renin, angiotensin II and aldosterone levels were measured. Results showed that, after 6, 8 and 10 weeks, LVEF in warming yang, invigorating qi, warming yang+invigorating qi and captopril group was significantly higher than model group (P < 0.05, and the plasma renin, angiotensin II and aldosterone levels in warming yang, invigorating qi, warming yang+invigorating qi and captopril groups were significantly lower than model group (P < 0.05. Renin angiotensin II and aldosterone levels in invigorating qi, warming yang+invigorating qi and captopril groups after 10 weeks was significantly lower than after 6 weeks (P < 0.05; aldosterone level in captopril groups after 10 weeks was significantly lower than after 6 weeks (P < 0.05. Warming yang and invigorating qi prescription can improve LVEF in rats with heart failure after myocardial infarction, which may be related with the inhibition of RAAS activation.

  3. Global Warming: A Myth?

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 6; Issue 7. Global Warming: A Myth? - Credibility of Climate Scenarios Predicted by Systems Simulations. Deepanjan Majumdar. General Article Volume 6 Issue 7 July 2001 pp 13-21 ...

  4. Acceptance test report for 241-AW process air system

    International Nuclear Information System (INIS)

    Kostelnik, A.J.

    1994-01-01

    The acceptance test procedure (ATP) for the compressed air system at building 241-AW-273 was completed on March 11, 1993. The system was upgraded to provide a reliable source of compressed air to the tank farm. The upgrade included the demolition of the existing air compressor and associated piping, as well as the installation of a new air compressor with a closed loop cooling system. A compressed air cross-tie was added to allow the process air compressor to function as a back-up to the existing instrument air compressor. The purpose of the ATP was to achieve three primary objectives: verify system upgrade in accordance with the design media; provide functional test of system components and controls; and prepare the system for the Operational Test. The ATP was successfully completed with thirteen exceptions, which were resolved prior to completing the acceptance test. The repaired exceptions had no impact to safety or the environment and are briefly summarized. Testing ensured that the system was installed per design, that its components function as required and that it is ready for operational testing and subsequent turnover to operations

  5. Optimizing the Air Dissolution Parameters in an Unpacked Dissolved Air Flotation System

    Directory of Open Access Journals (Sweden)

    Adam Dassey

    2011-12-01

    Full Text Available Due to the various parameters that influence air solubility and microbubble production in dissolved air flotation (DAF, a multitude of values that cover a large range for these parameters are suggested for field systems. An unpacked saturator and an air quantification unit were designed to specify the effects of power, pressure, temperature, hydraulic retention time, and air flow on the DAF performance. It was determined that a pressure of 621 kPa, hydraulic retention time of 18.2 min, and air flow of 8.5 L/h would be the best controlled parameters for maximum efficiency in this unit. A temperature of 7 °C showed the greatest microbubble production, but temperature control would not be expected in actual application. The maximum microbubble flow from the designed system produced 30 mL of air (±1.5 per L of water under these conditions with immediate startup. The maximum theoretical dissolved air volume of 107 mL (±6 was achieved at a retention time of 2 h and a pressure of 621 kPa. To isolate and have better control over the various DAF operational parameters, the DAF unit was operated without the unsaturated flow stream. This mode of operation led to the formation of large bubbles at peak bubble production rates. In a real-world application, the large bubble formation will be avoided by mixing with raw unsaturated stream and by altering the location of dissolved air output flow.

  6. Automated control system for unmanned combat air vehicle

    Science.gov (United States)

    Tsekova, Valentina

    2009-10-01

    A type of automated control system (ACS) for unmanned combat air vehicle (UCAV) is suggested. ACS framework is synthesized out of its block diagram. The diagram and the equations enclosed to them could be used for basic calculations and researches of ACS for unmanned air vehicle.

  7. Air-cleaning systems for sodium-fire-aerosol control

    International Nuclear Information System (INIS)

    Hilliard, R.K.; Muhlestein, L.D.

    1982-05-01

    A development program has been carried out at the Hanford Engineering Development Laboratory (HEDL) with the purpose of developing and proof testing air cleaning components and systems for use under severe sodium fire conditions, including those involving high levels of radioactivity. The air cleaning components tested can be classified as either dry filters or aqueous scrubbers. Test results are presented

  8. Interaction of Air Flow in Complex Ventilation Systems

    Directory of Open Access Journals (Sweden)

    Zhorzh G. Levitskiy

    2013-01-01

    Full Text Available The article presents the results of study of interaction of air flow in complex ventilation systems. The study used Taylor and Maclaurin’s series and Lagrange formula to create the functional connections on estimation of the impact of changing aerodynamic parameters of one or several simultaneously working regulators on the air flow distribution in mines

  9. Choice of compressed air fed system of a uranium mine

    International Nuclear Information System (INIS)

    Li Congkui; Lei Zeyong

    2006-01-01

    The selection of compressed air fed system in a uranium mine is discussed. The research indicates that the movable air compressor is better than the fixed one in energy saving, once capital cost and operational cost when it is applied in an underground uranium mine. (authors)

  10. Yield-scaled global warming potential of two irrigation management systems in a highly productive rice system

    Directory of Open Access Journals (Sweden)

    Silvana Tarlera

    2016-02-01

    Full Text Available ABSTRACT Water management impacts both methane (CH4 and nitrous oxide (N2O emissions from rice paddy fields. Although controlled irrigation is one of the most important tools for reducing CH4emission in rice production systems it can also increase N2O emissions and reduce crop yields. Over three years, CH4 and N2O emissions were measured in a rice field in Uruguay under two different irrigation management systems, using static closed chambers: conventional water management (continuous flooding after 30 days of emergence, CF30; and an alternative system (controlled deficit irrigation allowing for wetting and drying, AWDI. AWDI showed mean cumulative CH4 emission values of 98.4 kg CH4 ha−1, 55 % lower compared to CF30, while no differences in nitrous oxide emissions were observed between treatments ( p > 0.05. No yield differences between irrigation systems were observed in two of the rice seasons ( p > 0.05 while AWDI promoted yield reduction in one of the seasons ( p< 0.05. When rice yield and greenhouse gases (GHG emissions were considered together, the AWDI irrigation system allowed for lower yield-scaled total global warming potential (GWP. Higher irrigation water productivity was achieved under AWDI in two of the three rice seasons. These findings suggest that AWDI could be an option for reducing GHG emissions and increasing irrigation water productivity. However, AWDI may compromise grain yield in certain years, reflecting the importance of the need for fine tuning of this irrigation strategy and an assessment of the overall tradeoff between relationships in order to promote its adoption by farmers.

  11. Performance of a hydraulic air compressor for use in compressed air energy storage power systems

    Energy Technology Data Exchange (ETDEWEB)

    Berghmans, J. A.; Ahrens, F. W.

    1978-01-01

    A fluid mechanical analysis of a hydraulic air compression system for Compressed Air Energy Storage (CAES) application is presented. With this compression concept, air is charged into an underground reservoir, for later use in power generation, by entraining bubbles into a downward flow of water from a surface reservoir. Upon releasing the air in the underground reservoir, the water is pumped back to the surface. The analytical model delineated is used to predict the hydraulic compressor performance characteristics (pumping power, pump head, compression efficiency) as a function of water flow rate and system geometrical parameters. The results indicate that, although large water pumps are needed, efficiencies as high as 90% (relative to ideal isothermal compression) can be expected. This should result in lower compression power than for conventional compressor systems, while eliminating the need for the usual intercoolers and aftercooler.

  12. Compressed air systems. A guidebook on energy and cost savings

    Energy Technology Data Exchange (ETDEWEB)

    1984-03-30

    This guidebook shows how energy can be saved in compressed air systems. It discusses basic compressed air systems which are typical of those found in industry and describes them and the engineering practices behind them. Energy conservation recommendations follow. These recommendations cover equipment selection, design, maintenance, and operation. Included is information which will help the reader to make economic evaluations of various engineering and equipment alternatives as they affect operations and costs. The appendices include some modern computer based approaches to predicting pressure drop for designing compressed air distribution systems. Also included is a bibliography providing leads for further and more detailed technical information on these and related subjects.

  13. DESIGN a solar hybrid air conditioning compressor system

    Directory of Open Access Journals (Sweden)

    Khalaji Assadi M.

    2016-01-01

    Full Text Available To develop and integrate solar hybrid system into conventional air conditioning system which provides the same cooling load with considerably less electricity demand. Solar evacuated tube and DC compressor are used for compressing the refrigerant in an air conditioning system, thus effectively reducing the air conditioning electricity consumption by up to 45%. For the flow through type selected geometry of the designed evacuated U-tube collector, a three dimensional simulation and analysis of the thermal performance was done, using the solar ray-tracing model provided by the ANSYS-FLUENT software.

  14. Test results of lithium pool-air reaction suppression systems

    International Nuclear Information System (INIS)

    Jeppson, D.W.

    1987-02-01

    Engineered reaction suppression systems were demonstrated to be effective in suppressing lithium pool-air reactions for lithium quantities up to 100 kg. Lithium pool-air reaction suppression system tests were conducted to evaluate suppression system effectiveness for potential use in fusion facilities in mitigating consequences of postulated lithium spills. Small-scale perforated and sacrificial cover plate suppression systems with delayed inert gas purging proved effective in controlling the lithium-air interaction for lithium quantities near 15 kg at initial temperatures up to 450 0 C. A large-scale suppression system with a sacrificial cover, a diverter plate, an inert gas atmosphere, and remotely retrievable catch pans proved effective in controlling lithium pool-air interaction for a 100-kg lithium discharge at an initial temperature of 550 0 C. This suppression system limited the maximum pool temperature to about 600 0 C less than that expected for a similar lithium pool-air reaction without a suppression system. Lithium aerosol release from this large-scale suppression system was a factor of about 10,000 less than that expected for a lithium pool-air reaction with no suppression system. Remote retrieval techniques for lithium cleanup, such as (1) in-place lithium siphoning and overhead crane dismantling, and (2) lithium catch pan removal by use of an overhead crane, were demonstrated as part of this large-scale test

  15. Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model

    Directory of Open Access Journals (Sweden)

    A. Gnanadesikan

    2012-03-01

    Full Text Available Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1 shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., suboxic waters does not increase under global warming, as these waters actually become more oxygenated. We show that the rise in dissolved oxygen in the tropical Pacific is associated with a drop in ventilation time. A term-by-term analysis within the least oxygenated waters shows an increased supply of dissolved oxygen due to lateral diffusion compensating an increase in remineralization within these highly hypoxic waters. This lateral diffusive flux is the result of an increase of ventilation along the Chilean coast, as a drying of the region under global warming opens up a region of wintertime convection in our model. The results highlight the potential sensitivity of suboxic waters to changes in subtropical ventilation as well as the importance of constraining lateral eddy transport of dissolved oxygen in such waters.

  16. Sensitivity of the Humboldt current system to global warming: a downscaling experiment of the IPSL-CM4 model

    Energy Technology Data Exchange (ETDEWEB)

    Echevin, Vincent [LOCEAN, Paris (France); Goubanova, Katerina; Dewitte, Boris [LEGOS, Toulouse (France); IMARPE, IGP, LEGOS, Lima (Peru); Belmadani, Ali [LOCEAN, Paris (France); LEGOS, Toulouse (France); University of Hawaii at Manoa, IPRC, International Pacific Research Center, SOEST, Honolulu, Hawaii (United States)

    2012-02-15

    The impact of climate warming on the seasonal variability of the Humboldt Current system ocean dynamics is investigated. The IPSL-CM4 large scale ocean circulation resulting from two contrasted climate scenarios, the so-called Preindustrial and quadrupling CO{sub 2}, are downscaled using an eddy-resolving regional ocean circulation model. The intense surface heating by the atmosphere in the quadrupling CO{sub 2} scenario leads to a strong increase of the surface density stratification, a thinner coastal jet, an enhanced Peru-Chile undercurrent, and an intensification of nearshore turbulence. Upwelling rates respond quasi-linearly to the change in wind stress associated with anthropogenic forcing, and show a moderate decrease in summer off Peru and a strong increase off Chile. Results from sensitivity experiments show that a 50% wind stress increase does not compensate for the surface warming resulting from heat flux forcing and that the associated mesoscale turbulence increase is a robust feature. (orig.)

  17. Designing self-monitoring warm-up strategy with blog-based learning system to support knowledge building

    Directory of Open Access Journals (Sweden)

    James Chan

    2012-03-01

    Full Text Available Preparing lessons before class is widely recognized as an effective means of increasing student motivation for classroom activities and learning outcome. However, the unclear status of lesson preparation generally discourages teachers and students from maintaining this effective learning strategy. This study applied the self-explanation theory and reading comprehension strategies to design a lesson warm-up mechanism that scaffolds knowledge building. A set of corresponding supporting tools were developed into a blog-based learning system (BBLS to implement the warm-up process. Results of a teaching experiment reveal positive effects of the tools on learning achievement, recall of old knowledge, connection between old and new knowledge, and understanding of new knowledge.

  18. METHODOLOGY FOR ANALYSIS OF DECISION MAKING IN AIR NAVIGATION SYSTEM

    Directory of Open Access Journals (Sweden)

    Volodymyr Kharchenko

    2011-03-01

    Full Text Available Abstract. In the research of Air Navigation System as a complex socio-technical system the methodologyof analysis of human-operator's decision-making has been developed. The significance of individualpsychologicalfactors as well as the impact of socio-psychological factors on the professional activities of ahuman-operator during the flight situation development from normal to catastrophic were analyzed. On thebasis of the reflexive theory of bipolar choice the expected risks of decision-making by the Air NavigationSystem's operator influenced by external environment, previous experience and intentions were identified.The methods for analysis of decision-making by the human-operator of Air Navigation System usingstochastic networks have been developed.Keywords: Air Navigation System, bipolar choice, human operator, decision-making, expected risk, individualpsychologicalfactors, methodology of analysis, reflexive model, socio-psychological factors, stochastic network.

  19. Investigation of a hybrid PVT air collector system

    Science.gov (United States)

    Haddad, S.; Touafek, K.; Mordjaoui, M.; Khelifa, A.; Tabet, I.

    2017-02-01

    The photovoltaic thermal hybrid (PVT) collectors, which simultaneously produce electricity and heat, are an alternative to photovoltaic modules and thermal collectors installed separately. Indeed, the heat extracted from the solar cell is used to heat water or air, thereby cooling the cell, and thus increasing its energy efficiency. This paper deals with a hybrid PVT air collector in which a new design has been proposed and tested. Its principle is based on the return of the preheating air to a second heating. The air thus passes twice under the solar cells before being evacuated to the outside of the collector (for space heating). The system is modular and expandable to cover large spaces to be heated. The experimental results of this novel design are presented and discussed under both normal and forced circulation. This technique of air return shows favorable results in terms of the quality of the heated air and electric power generation.

  20. Optimization of fog inlet air cooling system for combined cycle power plants using genetic algorithm

    International Nuclear Information System (INIS)

    Ehyaei, Mehdi A.; Tahani, Mojtaba; Ahmadi, Pouria; Esfandiari, Mohammad

    2015-01-01

    In this research paper, a comprehensive thermodynamic modeling of a combined cycle power plant is first conducted and the effects of gas turbine inlet fogging system on the first and second law efficiencies and net power outputs of combined cycle power plants are investigated. The combined cycle power plant (CCPP) considered for this study consist of a double pressure heat recovery steam generator (HRSG) to utilize the energy of exhaust leaving the gas turbine and produce superheated steam to generate electricity in the Rankine cycle. In order to enhance understanding of this research and come up with optimum performance assessment of the plant, a complete optimization is using a genetic algorithm conducted. In order to achieve this goal, a new objective function is defined for the system optimization including social cost of air pollution for the power generation systems. The objective function is based on the first law efficiency, energy cost and the external social cost of air pollution for an operational system. It is concluded that using inlet air cooling system for the CCPP system and its optimization results in an increase in the average output power, first and second law efficiencies by 17.24%, 3.6% and 3.5%, respectively, for three warm months of year. - Highlights: • To model the combined cycle power plant equipped with fog inlet air cooling method. • To conduct both exergy and economic analyses for better understanding. • To conduct a complete optimization using a genetic algorithm to determine the optimal design parameters of the system

  1. The Adverse Effects of Air Pollution on the Nervous System

    Science.gov (United States)

    Genc, Sermin; Zadeoglulari, Zeynep; Fuss, Stefan H.; Genc, Kursad

    2012-01-01

    Exposure to ambient air pollution is a serious and common public health concern associated with growing morbidity and mortality worldwide. In the last decades, the adverse effects of air pollution on the pulmonary and cardiovascular systems have been well established in a series of major epidemiological and observational studies. In the recent past, air pollution has also been associated with diseases of the central nervous system (CNS), including stroke, Alzheimer's disease, Parkinson's disease, and neurodevelopmental disorders. It has been demonstrated that various components of air pollution, such as nanosized particles, can easily translocate to the CNS where they can activate innate immune responses. Furthermore, systemic inflammation arising from the pulmonary or cardiovascular system can affect CNS health. Despite intense studies on the health effects of ambient air pollution, the underlying molecular mechanisms of susceptibility and disease remain largely elusive. However, emerging evidence suggests that air pollution-induced neuroinflammation, oxidative stress, microglial activation, cerebrovascular dysfunction, and alterations in the blood-brain barrier contribute to CNS pathology. A better understanding of the mediators and mechanisms will enable the development of new strategies to protect individuals at risk and to reduce detrimental effects of air pollution on the nervous system and mental health. PMID:22523490

  2. Heating, Ventilating, Air Conditioning and Dehumidifying Systems.

    Science.gov (United States)

    1980-08-01

    Availability and cost material of civilian labor and materiala . Accessibility The available transport and access facilities. Standards, The applicable...toilet facilities, washrooms, shower rooms, janitor’s closets and garbage rooms. Food handling areas include kitchens, dining rooms, dishwashing facilities...Officers Quarters, or individual quarters the exhaust air rate shall be 2 cfm per square foot of net floor area. I (4) For shower rooms with gang showers

  3. Long-term soil warming and Carbon Cycle Feedbacks to the Climate System

    Energy Technology Data Exchange (ETDEWEB)

    Melillo, Jerry M.

    2014-04-30

    The primary objective of the proposed research was to quantify and explain the effects of a sustained in situ 5oC soil temperature increase on net carbon (C) storage in a northeastern deciduous forest ecosystem. The research was done at an established soil warming experiment at the Harvard Forest in central Massachusetts – Barre Woods site established in 2001. In the field, a series of plant and soil measurements were made to quantify changes in C storage in the ecosystem and to provide insights into the possible relationships between C-storage changes and nitrogen (N) cycling changes in the warmed plots. Field measurements included: 1) annual woody increment; 2) litterfall; 3) carbon dioxide (CO2) efflux from the soil surface; 4) root biomass and respiration; 5) microbial biomass; and 6) net N mineralization and net nitrification rates. This research was designed to increase our understanding of how global warming will affect the capacity of temperate forest ecosystems to store C. The work explored how soil warming changes the interactions between the C and N cycles, and how these changes affect land-atmosphere feedbacks. This core research question framed the project – What are the effects of a sustained in situ 5oC soil temperature increase on net carbon (C) storage in a northeastern deciduous forest ecosystem? A second critical question was addressed in this research – What are the effects of a sustained in situ 5{degrees}C soil temperature increase on nitrogen (N) cycling in a northeastern deciduous forest ecosystem?

  4. Converting Constant Volume, Multizone Air Handling Systems to Energy Efficient Variable Air Volume Multizone Systems

    Science.gov (United States)

    2017-06-05

    management funds over multiple projects . 7.1.3 Energy Costs Energy costs for each air handler are broken into three modes representing the normalized...significant energy consumption reductions seen across all air handlers and operating modes (see Table 12), not all air handler retrofit projects ...39,000 Billion British Thermal Units (BBTUs) of installation energy consumption and between 14,816 and 26,475 individual multizone air handlers. Most

  5. Prototype air cleaning system for a firing range

    Energy Technology Data Exchange (ETDEWEB)

    Glissmeyer, J.A.; Mishima, J.; Bamberger, J.A.

    1985-01-01

    This report recommends air cleaning system components for the US Army Ballistics Research Laboratory's new large-caliber firing range, which is used for testing depleted uranium (DU) penetrators. The new air cleaning system has lower operating costs during the life of the system compared to that anticipated for the existing air cleaning system. The existing system consists of three banks of filters in series; the first two banks are prefilters and the last are high-efficiency particulate air (HEPA) filters. The principal disadvantage of the existing filters is that they are not cleanable and reusable. Pacific Northwest Laboratory focused the search for alternate air cleaning equipment on devices that do not employ liquids as part of the particle collection mechanism. Collected dry particles were assumed preferable to a liquid waste stream. The dry particle collection devices identified included electrostatic precipitators; inertial separators using turning vanes or cyclones; and several devices employing a filter medium such as baghouses, cartridge houses, cleanable filters, and noncleanable filters similar to those in the existing system. The economics of practical air cleaning systems employing the dry particle collection devices were evaluated in 294 different combinations. 7 references, 21 figures, 78 tables.

  6. Joint Integrated Air Defense Systems View (J-IADS-VIEW)

    National Research Council Canada - National Science Library

    Sutton, Mike

    2005-01-01

    ...) and their clients to visualize foreign Integrated Air Defense Systems (IADS) information. Current methods to disseminate IADS analysis are manually in nature and time intensive to produce meaningful reports...

  7. Joint Integrated Air Defense Systems View (J-IADS-VIEW)

    National Research Council Canada - National Science Library

    Sutton, Mike

    2006-01-01

    ...) and their clients to visualize foreign Integrated Air Defense Systems (IADS) information. Current methods to disseminate IADS analysis are manual in nature and time intensive to produce meaningful reports...

  8. CDC STATE System Tobacco Legislation - Smokefree Indoor Air

    Data.gov (United States)

    U.S. Department of Health & Human Services — 1995-2017. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation – Smokefree Indoor Air....

  9. CDC STATE System Tobacco Legislation - Smokefree Indoor Air

    Data.gov (United States)

    U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation – Smokefree Indoor Air. The...

  10. CDC STATE System Tobacco Legislation - Smokefree Indoor Air Summary

    Data.gov (United States)

    U.S. Department of Health & Human Services — 1995-2018. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation – Smokefree Indoor Air. The...

  11. CDC STATE System Tobacco Legislation - Smokefree Indoor Air Summary

    Data.gov (United States)

    U.S. Department of Health & Human Services — 1995-2017. Centers for Disease Control and Prevention (CDC). State Tobacco Activities Tracking and Evaluation (STATE) System. Legislation – Smokefree Indoor Air....

  12. Systemic Air Embolism After CT-guided Lung Biopsy

    Science.gov (United States)

    2017-11-27

    Patients Who Underwent Percutaneous Lung Biopsy Under CT Guidance; Patients Who Presented Systemic Air Embolism After Percutaneous Lung Biopsy Under CT Guidance Depicted at the Time of the Procedure on a Whole Thoracic CT

  13. Understanding why the volume of suboxic waters does not increase over centuries of global warming in an Earth System Model

    OpenAIRE

    A. Gnanadesikan; J. P. Dunne; J. John

    2012-01-01

    Global warming is expected to reduce oxygen solubility and vertical exchange in the ocean, changes which would be expected to result in an increase in the volume of hypoxic waters. A simulation made with a full Earth System model with dynamical atmosphere, ocean, sea ice and biogeochemical cycling (the Geophysical Fluid Dynamics Laboratory's Earth System Model 2.1) shows that this holds true if the condition for hypoxia is set relatively high. However, the volume of the most hypoxic (i.e., su...

  14. Mitigation of Global Warming with Focus on Personal Carbon Allowances

    DEFF Research Database (Denmark)

    Meyer, Niels I

    2008-01-01

    The mitigation of global warming requires new efficient systems and methods. The paper presents a new proposal called personal carbon allowances with caps on the CO2 emission from household heating and electricity and on emission from transport in private cars and in personal air flights. Results...

  15. Temperature conditions of hothouses during a warm season

    Directory of Open Access Journals (Sweden)

    Bodrov Valery

    2016-01-01

    Full Text Available On the basis of justification of the heat and mass transfer processes inside the hothouses during a warm season authors developed methods and means that control dynamics of temperature and humidity parameters and air conditions with the help of complex systems of removal of overheat in the hothouses during the all year round and diurnal operations at minimum power inputs.

  16. 14 CFR 29.1103 - Induction systems ducts and air duct systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Induction systems ducts and air duct....1103 Induction systems ducts and air duct systems. (a) Each induction system duct upstream of the first... it might cause a fire hazard. (b) Each duct must be strong enough to prevent induction system failure...

  17. Transformations in Air Transportation Systems For the 21st Century

    Science.gov (United States)

    Holmes, Bruce J.

    2004-01-01

    Globally, our transportation systems face increasingly discomforting realities: certain of the legacy air and ground infrastructures of the 20th century will not satisfy our 21st century mobility needs. The consequence of inaction is diminished quality of life and economic opportunity for those nations unable to transform from the 20th to 21st century systems. Clearly, new thinking is required regarding business models that cater to consumers value of time, airspace architectures that enable those new business models, and technology strategies for innovating at the system-of-networks level. This lecture proposes a structured way of thinking about transformation from the legacy systems of the 20th century toward new systems for the 21st century. The comparison and contrast between the legacy systems of the 20th century and the transformed systems of the 21st century provides insights into the structure of transformation of air transportation. Where the legacy systems tend to be analog (versus digital), centralized (versus distributed), and scheduled (versus on-demand) for example, transformed 21st century systems become capable of scalability through technological, business, and policy innovations. Where air mobility in our legacy systems of the 20th century brought economic opportunity and quality of life to large service markets, transformed air mobility of the 21st century becomes more equitable available to ever-thinner and widely distributed populations. Several technological developments in the traditional aircraft disciplines as well as in communication, navigation, surveillance and information systems create new foundations for 21st thinking about air transportation. One of the technological developments of importance arises from complexity science and modern network theory. Scale-free (i.e., scalable) networks represent a promising concept space for modeling airspace system architectures, and for assessing network performance in terms of robustness

  18. Accounting for global-mean warming and scaling uncertainties in climate change impact studies: application to a regulated lake system

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available A probabilistic assessment of climate change and related impacts should consider a large range of potential future climate scenarios. State-of-the-art climate models, especially coupled atmosphere-ocean general circulation models and Regional Climate Models (RCMs cannot, however, be used to simulate such a large number of scenarios. This paper presents a methodology for obtaining future climate scenarios through a simple scaling methodology. The projections of several key meteorological variables obtained from a few regional climate model runs are scaled, based on different global-mean warming projections drawn in a probability distribution of future global-mean warming. The resulting climate change scenarios are used to drive a hydrological and a water management model to analyse the potential climate change impacts on a water resources system. This methodology enables a joint quantification of the climate change impact uncertainty induced by the global-mean warming scenarios and the regional climate response. It is applied to a case study in Switzerland, a water resources system formed by three interconnected lakes located in the Jura Mountains. The system behaviour is simulated for a control period (1961–1990 and a future period (2070–2099. The potential climate change impacts are assessed through a set of impact indices related to different fields of interest (hydrology, agriculture and ecology. The results obtained show that future climate conditions will have a significant influence on the performance of the system and that the uncertainty induced by the inter-RCM variability will contribute to much of the uncertainty of the prediction of the total impact. These CSRs cover the area considered in the 2001–2004 EU funded project SWURVE.

  19. Investigation on wind energy-compressed air power system.

    Science.gov (United States)

    Jia, Guang-Zheng; Wang, Xuan-Yin; Wu, Gen-Mao

    2004-03-01

    Wind energy is a pollution free and renewable resource widely distributed over China. Aimed at protecting the environment and enlarging application of wind energy, a new approach to application of wind energy by using compressed air power to some extent instead of electricity put forward. This includes: explaining the working principles and characteristics of the wind energy-compressed air power system; discussing the compatibility of wind energy and compressor capacity; presenting the theoretical model and computational simulation of the system. The obtained compressor capacity vs wind power relationship in certain wind velocity range can be helpful in the designing of the wind power-compressed air system. Results of investigations on the application of high-pressure compressed air for pressure reduction led to conclusion that pressure reduction with expander is better than the throttle regulator in energy saving.

  20. Optimizing dissolved air flotation design system

    Directory of Open Access Journals (Sweden)

    L.A. Féris

    2000-12-01

    Full Text Available Dissolved Air (Pressure Flotation-DAF, is a well-established separation process that employs micro-bubbles as a carrier phase. This work shows results concerning bubble generation at low working pressures in modified DAF-units to improve the collection of fragile coagula by bubbles. DAF of Fe (OH3 (as model was studied as a function of saturation pressure in the absence and presence of surfactants in the saturator. DAF was possible at 2 atm by lowering the air/water surface tension. This fact, which leads to substantial energy savings, was explained in terms of decreasing the "minimum" energy required for bubble nucleation and cavity in the nozzle. More, bubbles-fragile coagula attachment was improved by dividing the recycling water into two: 1 the inclined inlet to the cell (traditional and 2 inside the separation tank through a water flow inlet situated below the floating bed using a "mushroom" type diffuser. Because of the reduction observed in the degree of turbulence in the conventional collection zone, DAF performance improved yielding high precipitate recoveries.

  1. A Data Analysis of Naval Air Systems Command Funding Documents

    Science.gov (United States)

    2017-06-01

    value in excess of 146 billion dollars. NAVAIR uses the Navy Enterprise Resource Planning ( ERP ) system to process its financial transactions and...resource planning ( ERP ), Naval Air Systems Command (NAVAIR), purchase requests (PR), funding documents, Economy Act Order, intragovernmental transfers...Planning ( ERP ) system to process its financial transactions and, since its implementation, there has been an increase in the overall number of

  2. Design of energy efficient ventilation and air-conditioning systems

    CERN Document Server

    Seppänen, Olli; Bertilsson, Thore; Maripuu, Mari-Liis; Lamy, Hervé; Vanden Borre, Alex

    2012-01-01

    This guidebook covers numerous system components of ventilation and air-conditioning systems and shows how they can be improved by applying the latest technology products. Special attention is paid to details, which are often overlooked in the daily design practice, resulting in poor performance of high quality products once they are installed in the building system.

  3. Mound Laboratory's Air Surveillance System

    Energy Technology Data Exchange (ETDEWEB)

    Carfagno, D. G.

    1974-12-31

    A comprehensive air surveillance system was developed. The system includes surveillance of the source, transport conditions, and concentration at the receptor sites. An unusual aspect of the system is the implementation of off-site sampling programs through local governmental agencies. Background levels of radioactivity are routinely determined.

  4. Designing and testing the optimum design of automotive air-to-air thermoelectric air conditioner (TEAC) system

    International Nuclear Information System (INIS)

    Attar, Alaa; Lee, HoSung

    2016-01-01

    Highlights: • The optimum design of automotive thermoelectric AC system is proposed. • It is optimized by combining the thermal isolation and the dimensionless methods. • An experiment is conducted to validate the analytical design. - Abstract: The current project is discussing the optimization of counter flow air-to-air thermoelectric air conditioners (TEAC) system. Previous work showed an analytical model with experimental validation of a unit cell of TEAC system. However, the focus of this work is to simulate the optimum design of a whole TEAC system from given inlet parameters (i.e., hot and cold air mass flow rates and ambient temperatures). The analytical model was built by combining an optimal design method with dimensional analysis, which was recently developed, and the thermal isolation method in order to optimize the thermoelectric parameters (i.e., electrical current supplied and the number of thermocouples or the geometric factor, simultaneously). Moreover, based on the designed model, an experiment was conducted in order to study the accuracy of the analytical model. Even though the analytical model was built based on the thermoelectric ideal equations, it shows a good agreement with the experiment. This agreement was mainly a result of the use of the thermoelectric effective material properties which are obtained from the measured maximum thermoelectric module parameters. Since the experiment validate the analytical model, this model provides uncomplicated method to study the optimum design at given inputs.

  5. Applications Guide for Compressed Air Systems

    National Research Council Canada - National Science Library

    Lin, Mike

    2001-01-01

    .... Although CA systems are a very convenient power source, they are not cheap to operate. However, nearly all industrial plants can realize from 25 to 40 percent savings on the power costs for the CA system without additional capital expenditures...

  6. Impact of the Air-Conditioning System on the Power Consumption of an Electric Vehicle Powered by Lithium-Ion Battery

    OpenAIRE

    Brahim Mebarki; Belkacem Draoui; Boumediène Allaou; Lakhdar Rahmani; Elhadj Benachour

    2013-01-01

    The car occupies the daily universe of our society; however, noise pollution, global warming gas emissions, and increased fuel consumption are constantly increasing. The electric vehicle is one of the recommended solutions by the raison of its zero emission. Heating and air-conditioning (HVAC) system is a part of the power system of the vehicle when the purpose is to provide complete thermal comfort for its occupants, however it requires far more energy than any other car accessory. Electric ...

  7. Small photovoltaic setup for the air conditioning system

    Directory of Open Access Journals (Sweden)

    Masiukiewicz Maciej

    2017-01-01

    Full Text Available The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES. The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system. Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

  8. Small photovoltaic setup for the air conditioning system

    Science.gov (United States)

    Masiukiewicz, Maciej

    2017-10-01

    The increasing interest in air conditioning systems for residential applications in Poland will certainly increase the demand for electricity during the summer period. Due to this fact a growing interest in solutions that help to lower the electricity consumption in this sector is observed. The problem of increased energy demand for air conditioning purposes can be solved by transfer the consumption of electricity from the grid system to renewable energy sources (RES). The greatest demand for cooling occurs during the biggest sunlight. This is the basis for the analysis of technical power system based on photovoltaic cells (PV) to power the split type air conditioner. The object of the study was the commercial residential airconditioning inverter units with a capacity of 2.5kW. A network electricity production system for their own use with the possibility of buffering energy in batteries (OFF-GRID system). Currently, on the Polish market, there are no developed complete solutions dedicated to air conditioning systems based on PV. In Poland, solar energy is mainly used for heat production in solar collectors. The proposed solution will help to increase the popularity of PV systems in the Polish market as an alternative to other RES. The basic conclusion is that the amount of PV energy generated was sufficient to cover the daily energy requirement of the air conditioner.

  9. Optimal Control of Hybrid Systems in Air Traffic Applications

    Science.gov (United States)

    Kamgarpour, Maryam

    Growing concerns over the scalability of air traffic operations, air transportation fuel emissions and prices, as well as the advent of communication and sensing technologies motivate improvements to the air traffic management system. To address such improvements, in this thesis a hybrid dynamical model as an abstraction of the air traffic system is considered. Wind and hazardous weather impacts are included using a stochastic model. This thesis focuses on the design of algorithms for verification and control of hybrid and stochastic dynamical systems and the application of these algorithms to air traffic management problems. In the deterministic setting, a numerically efficient algorithm for optimal control of hybrid systems is proposed based on extensions of classical optimal control techniques. This algorithm is applied to optimize the trajectory of an Airbus 320 aircraft in the presence of wind and storms. In the stochastic setting, the verification problem of reaching a target set while avoiding obstacles (reach-avoid) is formulated as a two-player game to account for external agents' influence on system dynamics. The solution approach is applied to air traffic conflict prediction in the presence of stochastic wind. Due to the uncertainty in forecasts of the hazardous weather, and hence the unsafe regions of airspace for aircraft flight, the reach-avoid framework is extended to account for stochastic target and safe sets. This methodology is used to maximize the probability of the safety of aircraft paths through hazardous weather. Finally, the problem of modeling and optimization of arrival air traffic and runway configuration in dense airspace subject to stochastic weather data is addressed. This problem is formulated as a hybrid optimal control problem and is solved with a hierarchical approach that decouples safety and performance. As illustrated with this problem, the large scale of air traffic operations motivates future work on the efficient

  10. Experimental analysis of fuzzy controlled energy efficient demand controlled ventilation economizer cycle variable air volume air conditioning system

    Directory of Open Access Journals (Sweden)

    Rajagopalan Parameshwaran

    2008-01-01

    Full Text Available In the quest for energy conservative building design, there is now a great opportunity for a flexible and sophisticated air conditioning system capable of addressing better thermal comfort, indoor air quality, and energy efficiency, that are strongly desired. The variable refrigerant volume air conditioning system provides considerable energy savings, cost effectiveness and reduced space requirements. Applications of intelligent control like fuzzy logic controller, especially adapted to variable air volume air conditioning systems, have drawn more interest in recent years than classical control systems. An experimental analysis was performed to investigate the inherent operational characteristics of the combined variable refrigerant volume and variable air volume air conditioning systems under fixed ventilation, demand controlled ventilation, and combined demand controlled ventilation and economizer cycle techniques for two seasonal conditions. The test results of the variable refrigerant volume and variable air volume air conditioning system for each techniques are presented. The test results infer that the system controlled by fuzzy logic methodology and operated under the CO2 based mechanical ventilation scheme, effectively yields 37% and 56% per day of average energy-saving in summer and winter conditions, respectively. Based on the experimental results, the fuzzy based combined system can be considered to be an alternative energy efficient air conditioning scheme, having significant energy-saving potential compared to the conventional constant air volume air conditioning system.

  11. Technology of Measuring equipment for Air Pollution. Development of Mobile Air Pollution monitoring system (LIDAR)

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Hyung Ki; Song, Ky Seok; Rhee, Young Joo; Kim, Duck Hyun; Yang, Ki Ho; Lee, Jong Min; Cha, Byung Heon; Lee, Kang Soo

    1999-01-01

    Most air pollution monitoring technologies accompany a time-consuming sample treatment process and provides pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR (Light detection and ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The goal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols.

  12. Technology of Measuring equipment for Air Pollution. Development of Mobile Air Pollution monitoring system (LIDAR)

    International Nuclear Information System (INIS)

    Cha, Hyung Ki; Song, Ky Seok; Rhee, Young Joo; Kim, Duck Hyun; Yang, Ki Ho; Lee, Jong Min; Cha, Byung Heon; Lee, Kang Soo

    1999-01-01

    Most air pollution monitoring technologies accompany a time-consuming sample treatment process and provides pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR (Light detection and ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The goal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols

  13. Toxicity of a metal(loid)-polluted agricultural soil to Enchytraeus crypticus changes under a global warming perspective: Variations in air temperature and soil moisture content.

    Science.gov (United States)

    González-Alcaraz, M Nazaret; van Gestel, Cornelis A M

    2016-12-15

    This study aimed to assess how the current global warming perspective, with increasing air temperature (20°C vs. 25°C) and decreasing soil moisture content (50% vs. 30% of the soil water holding capacity, WHC), affected the toxicity of a metal(loid)-polluted agricultural soil to Enchytraeus crypticus. Enchytraeids were exposed for 21d to a dilution series of the agricultural soil with Lufa 2.2 control soil under four climate situations: 20°C+50% WHC (standard conditions), 20°C+30% WHC, 25°C+50% WHC, and 25°C+30% WHC. Survival, reproduction and bioaccumulation of As, Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn were obtained as endpoints. Reproduction was more sensitive to both climate factors and metal(loid) pollution. High soil salinity (electrical conductivity~3dSm -1 ) and clay texture, even without the presence of high metal(loid) concentrations, affected enchytraeid performance especially at drier conditions (≥80% reduction in reproduction). The toxicity of the agricultural soil increased at drier conditions (10% reduction in EC10 and EC50 values for the effect on enchytraeid reproduction). Changes in enchytraeid performance were accompanied by changes in As, Fe, Mn, Pb and Zn bioaccumulation, with lower body concentrations at drier conditions probably due to greater competition with soluble salts in the case of Fe, Mn, Pb and Zn. This study shows that apart from high metal(loid) concentrations other soil properties (e.g. salinity and texture) may be partially responsible for the toxicity of metal(loid)-polluted soils to soil invertebrates, especially under changing climate conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Ambient air pollution associated to domestic wood burning heating systems

    International Nuclear Information System (INIS)

    Friboulet, I.; Durif, M.; Malherbe, L.

    2009-01-01

    Main publications are considering effects of wood burning appliances on indoor air quality, which is a major issue in some countries. But impacts on ambient air, close environment and human exposure are rather poorly characterised so far. Besides, woods burning for domestic purpose may develop in the next years while promoting bio fuels. The aim of the ongoing study is to assess in which conditions associated air pollution and population exposure could be significant, this poster shows preliminary results of the impact of a village of 98 houses equipped with a wood burning heating system. (N.C.)

  15. Measurement results obtained from air quality monitoring system

    Energy Technology Data Exchange (ETDEWEB)

    Turzanski, P.K.; Beres, R. [Provincial Inspection of Environmental Protection, Cracow (Poland)

    1995-12-31

    An automatic system of air pollution monitoring operates in Cracow since 1991. The organization, assembling and start-up of the network is a result of joint efforts of the US Environmental Protection Agency and the Cracow environmental protection service. At present the automatic monitoring network is operated by the Provincial Inspection of Environmental Protection. There are in total seven stationary stations situated in Cracow to measure air pollution. These stations are supported continuously by one semi-mobile (transportable) station. It allows to modify periodically the area under investigation and therefore the 3-dimensional picture of creation and distribution of air pollutants within Cracow area could be more intelligible.

  16. Refrigeration and global warming

    International Nuclear Information System (INIS)

    Anon.

    1997-01-01

    Some aspects of global warming in general, and the implications for refrigerants and refrigerator efficiency in particular, are briefly considered in a question and answer format. The concepts of Global Warming Potential (GWP) and Total Equivalent Warming Impact (TEWI) are explained. GWP is an index which allows a simple comparison to be make between the warming effects of different gases on a kg to kg basis relative to carbon. The GWP depends both on the lifetime of a substance in the atmosphere and its infra-red absorption capacity. The overall warming effect of operating a refrigeration system for its entire life is measured by its TEWI. Chloroflourocarbons (CFCs) which have been widely used as refrigerants are powerful greenhouse gases with high GWPs. Because of the bank of CFCs in refrigerating systems, their levels in the atmosphere are still increasing and it will be some time before refrigerant changes will be effective in reducing the warming effects of refrigerant releases. Hydrocarbons, hydroflourocarbons and ammonia all have a part to play as substitute refrigerants. Refrigerator efficiency is very important in terms of reducing CO 2 emissions. (UK)

  17. FFTF-containment air-cleaning system

    International Nuclear Information System (INIS)

    Mahaffey, M.K.; Stepnewski, D.D.

    1981-01-01

    The FFTF Containment can accommodate all design basis events and the hypothetical core disruptive accident with adequate margin without a venting or purging system; however, in concert with the development objective, a system was designed and constructed to evaluate technology related to containment atmosphere venting and cleanup functions. The system can be used to purge high H 2 concentrations or to vent excessive containment pressure. In either case containment atmosphere is exhausted through an aqueous scrubber system consisting of a venturi scrubber and fibrous filter bank

  18. Application of solar energy to air conditioning systems

    Science.gov (United States)

    Nash, J. M.; Harstad, A. J.

    1976-01-01

    The results of a survey of solar energy system applications of air conditioning are summarized. Techniques discussed are both solar powered (absorption cycle and the heat engine/Rankine cycle) and solar related (heat pump). Brief descriptions of the physical implications of various air conditioning techniques, discussions of status, proposed technological improvements, methods of utilization and simulation models are presented, along with an extensive bibliography of related literature.

  19. Artificial immune system approach for air combat maneuvering

    Science.gov (United States)

    Kaneshige, John; Krishnakumar, Kalmanje

    2007-04-01

    Since future air combat missions will involve both manned and unmanned aircraft, the primary motivation for this research is to enable unmanned aircraft with intelligent maneuvering capabilities. During air combat maneuvering, pilots use their knowledge and experience of maneuvering strategies and tactics to determine the best course of action. As a result, we try to capture these aspects using an artificial immune system approach. The biological immune system protects the body against intruders by recognizing and destroying harmful cells or molecules. It can be thought of as a robust adaptive system that is capable of dealing with an enormous variety of disturbances and uncertainties. However, another critical aspect of the immune system is that it can remember how previous encounters were successfully defeated. As a result, it can respond faster to similar encounters in the future. This paper describes how an artificial immune system is used to select and construct air combat maneuvers. These maneuvers are composed of autopilot mode and target commands, which represent the low-level building blocks of the parameterized system. The resulting command sequences are sent to a tactical autopilot system, which has been enhanced with additional modes and an aggressiveness factor for enabling high performance maneuvers. Just as vaccinations train the biological immune system how to combat intruders, training sets are used to teach the maneuvering system how to respond to different enemy aircraft situations. Simulation results are presented, which demonstrate the potential of using immunized maneuver selection for the purposes of air combat maneuvering.

  20. Infrared Laser System for Extended Area Monitoring of Air Pollution

    Science.gov (United States)

    Snowman, L. R.; Gillmeister, R. J.

    1971-01-01

    An atmospheric pollution monitoring system using a spectrally scanning laser has been developed by the General Electric Company. This paper will report on an evaluation of a breadboard model, and will discuss applications of the concept to various ambient air monitoring situations. The system is adaptable to other tunable lasers. Operating in the middle infrared region, the system uses retroreflectors to measure average concentrations over long paths at low, safe power levels. The concept shows promise of meeting operational needs in ambient air monitoring and providing new data for atmospheric research.

  1. A zero-power warming chamber for investigating plant responses to rising temperature

    Science.gov (United States)

    Lewin, Keith F.; McMahon, Andrew M.; Ely, Kim S.; Serbin, Shawn P.; Rogers, Alistair

    2017-09-01

    Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate the mean daily air temperature by ˜ 1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be ˜ 2-3 °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW) chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. The approach we describe is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming approaches is desired.

  2. A zero-power warming chamber for investigating plant responses to rising temperature

    Directory of Open Access Journals (Sweden)

    K. F. Lewin

    2017-09-01

    Full Text Available Advances in understanding and model representation of plant and ecosystem responses to rising temperature have typically required temperature manipulation of research plots, particularly when considering warming scenarios that exceed current climate envelopes. In remote or logistically challenging locations, passive warming using solar radiation is often the only viable approach for temperature manipulation. However, current passive warming approaches are only able to elevate the mean daily air temperature by  ∼  1.5 °C. Motivated by our need to understand temperature acclimation in the Arctic, where warming has been markedly greater than the global average and where future warming is projected to be  ∼  2–3 °C by the middle of the century; we have developed an alternative approach to passive warming. Our zero-power warming (ZPW chamber requires no electrical power for fully autonomous operation. It uses a novel system of internal and external heat exchangers that allow differential actuation of pistons in coupled cylinders to control chamber venting. This enables the ZPW chamber venting to respond to the difference between the external and internal air temperatures, thereby increasing the potential for warming and eliminating the risk of overheating. During the thaw season on the coastal tundra of northern Alaska our ZPW chamber was able to elevate the mean daily air temperature 2.6 °C above ambient, double the warming achieved by an adjacent passively warmed control chamber that lacked our hydraulic system. We describe the construction, evaluation and performance of our ZPW chamber and discuss the impact of potential artefacts associated with the design and its operation on the Arctic tundra. The approach we describe is highly flexible and tunable, enabling customization for use in many different environments where significantly greater temperature manipulation than that possible with existing passive warming

  3. A New Control and Design of PEM Fuel Cell System Powered Diffused Air Aeration System

    Directory of Open Access Journals (Sweden)

    Hassen T. Dorrah

    2012-06-01

    Full Text Available The goal of aquaculture ponds is to maximize production and profits while holding labor and management efforts to the minimum. Poor water quality in most ponds causes risk of fish kills, disease outbreaks which lead to minimization of pond production. Dissolved Oxygen (DO is considered to be among the most important water quality parameters in fish culture. Fish ponds in aquaculture farms are usually located in remote areas where grid lines are at far distance. Aeration of ponds is required to prevent mortality and to intensify production, especially when feeding is practical, and in warm regions. To increase pond production it is necessary to control dissolved oxygen. Aeration offers the most immediate and practical solution to water quality problems encountered at higher stocking and feeding rates. Many units of aeration system are electrical units so using a continuous, high reliability, affordable, and environmentally friendly power sources is necessary. Fuel cells have become one of the major areas of research in the academia and the industry. Aeration of water by using PEM fuel cell power is not only a new application of the renewable energy, but also, it provides an affordable method to promote biodiversity in stagnant ponds and lakes. This paper presents a new design and control of PEM fuel cell powered a diffused air aeration system for a shrimp farm in Mersa Matruh in Egypt. Also Artificial intelligence (AI control techniques are used to control the fuel cell output power by controlling its input gases flow rate. Moreover the mathematical modeling and simulation of PEM fuel cell is introduced. A comparative study is applied between the performance of fuzzy logic controller (FLC and neural network controller (NNC. The results show the effectiveness of NNC over FLC.

  4. Improving Compressed Air System Performance: A Sourcebook for Industry

    Energy Technology Data Exchange (ETDEWEB)

    2003-11-01

    NREL will produce this sourcebook for DOE's Industrial Technologies Office as part of a series of documents on industrial energy equipment. The sourcebook is a reference for industrial compressed air system users, outlining opportunities to improve system efficiency.

  5. Magnetically tuned, robust and efficient filtering system for spatially multimode quantum memory in warm atomic vapors.

    Science.gov (United States)

    Dąbrowski, M; Chrapkiewicz, R; Wasilewski, W

    2016-11-12

    Warm atomic vapor quantum memories are simple and robust, yet suffer from a number of parasitic processes which produce excess noise. For operating in a single-photon regime precise filtering of the output light is essential. Here, we report a combination of magnetically tuned absorption and Faraday filters, both light-direction insensitive, which stop the driving lasers and attenuate spurious fluorescence and four-wave mixing while transmitting narrowband Stokes and anti-Stokes photons generated in write-in and readout processes. We characterize both filters with respect to adjustable working parameters. We demonstrate a significant increase in the signal-to-noise ratio upon applying the filters seen qualitatively in measurements of correlation between the Raman scattered photons.

  6. Drying unit in warm pure water pulling up system. Onjunsui hikiage hoshiki ni okeru kanso sochi

    Energy Technology Data Exchange (ETDEWEB)

    Shibano, Y. (Tokyo (Japan))

    1991-08-26

    This invention provides a means of drying which retains an object to be cleaned/dried, prevents the building up of water at the contact part of a retainer, dries the whole body of the object to be cleaned/dried and prevents the stains. In other words, in the invention, after the cleaning of such simple-shaped objects as a lense, optical disc, liquid crystal panel and a solar cell, which have relatively smooth surfaces, they are dipped in warm pure water set on the retaining tools of up/down jigs for drying, and then pulled slowly upwards and the objects are dried utilizing the surface tension of water. A means of water drop removal is placed in a space between the contacting part of the retaining tool in the elevator jig and the surface of the objects to be cleaned. 5 figs.

  7. ECOLO-HOUSE in the heavy snow-fall region. Study of the ventilating function that the heat collecting system of the air duct utilizing attic has; Yukiguni ECOLO-HOUSE. Kison kaoku no yaneura wo riyoshita duct shunetsu system kanki kino hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Umemiya, H.; Hirosawa, K. [Yamagata University, Yamagata (Japan)

    1997-11-25

    This paper reports a duct heat collecting system installed in the ECOLO-HOUSE for snow countries. This system is an air heat collecting system of the outside air introducing type utilizing as a solar heat collector the single pitch roof often seen in snow countries. Outside air is introduced from below eaves into a heat collecting duct made by nailing plywoods onto rafters from the attic side to collect heat on the roof. Operating a sirocco fan connected to the induction duct located on the high-floor foundation sucks outside air from an air intake opening under the eaves into the heat collecting duct. Air which has absorbed heat on the roof and been warmed in the heat collecting duct by insolation goes into a heat collecting chamber. The air is sent into the high-floor foundation through the induction duct laid from the heat collecting chamber. Air is exchanged 8.7 times by the fan when it is operated all day continuously. Condensation in the fuel chamber floor and walls during the rainy season has disappeared, and so has odor at the same time. As a result of the humidity measurement, a location into which warm air is sent has difference in humidity as great as 15% from a location where no warm air is sent. 2 refs., 6 figs., 2 tabs.

  8. Modeling and Analysing of Air Filter in Air Intake System in Automobile Engine

    Directory of Open Access Journals (Sweden)

    R. Manikantan

    2013-01-01

    Full Text Available As the legislations on the emission and performance of automobiles are being made more stringent, the expected performance of all the subsystems of an internal combustion engine is also becoming crucial. Nowadays the engines are downsized, and their power increased the demand on the air intake system that has increased phenomenally. Hence, an analysis was carried on a typical air filter fitted into the intake system to determine its flow characteristics. In the present investigation, a CAD model of an existing air filter was designed, and CFD analysis was done pertaining to various operating regimes of an internal combustion engine. The numerical results were validated with the experimental data. From the postprocessed result, we can see that there is a deficit in the design of the present filter, as the bottom portion of the filter is preventing the upward movement of air. Hence, the intake passage can be rearranged to provide an upward tangential motion, which can enhance the removal of larger dust and soot particles effectively by the inertial action of air alone.

  9. Experimental investigation of a two-inlet air-based building integrated photovoltaic/thermal (BIPV/T) system

    International Nuclear Information System (INIS)

    Yang, Tingting; Athienitis, Andreas K.

    2015-01-01

    Highlights: • BIPV/T system thermal efficiency is 5% higher using two inlets compared to one. • BIPV/T thermal efficiency is 7.6% higher using semi-transparent than opaque PV. • Detailed air temperature profile in BIPV/T channel is obtained. • Nusselt number correlations are developed. - Abstract: An experimental study of thermal characteristics of a novel two-inlet air-based open-loop building integrated photovoltaic/thermal (BIPV/T) system using a full-scale solar simulator is presented. Experimental prototypes of one-inlet and two-inlet BIPV/T systems were constructed for conducting comparative experiments. Variations of BIPV/T systems are also investigated including systems employing opaque mono-crystalline silicon photovoltaic (PV) panels and systems employing semi-transparent mono-crystalline PV panels. Experimental results demonstrate that an equivalent two-inlet system with frameless PV panels can increase the thermal efficiency by 5% compared to a conventional one-inlet system, and that the BIPV/T system with semi-transparent PV panels achieves 7.6% higher thermal efficiency due to the absorption of some solar radiation at the bottom surface in the BIPV/T system cavity. Also, the two-inlet BIPV/T design is easily implemented and does not add significant cost. Detailed air temperature measurements reveal that the mixing of the warm outlet air from the first section and the cool ambient air drawn in from the second inlet contributes to the improved performance of the two-inlet system. Based on a thermal network model of the BIPV/T system and experimental data, correlations are developed for the convective heat transfer coefficients in the two sections. These are necessary for further analysis and development of BIPV/T system with multiple inlets.

  10. Hydrogen-air energy storage gas-turbine system

    Science.gov (United States)

    Schastlivtsev, A. I.; Nazarova, O. V.

    2016-02-01

    A hydrogen-air energy storage gas-turbine unit is considered that can be used in both nuclear and centralized power industries. However, it is the most promising when used for power-generating plants based on renewable energy sources (RES). The basic feature of the energy storage system in question is combination of storing the energy in compressed air and hydrogen and oxygen produced by the water electrolysis. Such a process makes the energy storage more flexible, in particular, when applied to RES-based power-generating plants whose generation of power may considerably vary during the course of a day, and also reduces the specific cost of the system by decreasing the required volume of the reservoir. This will allow construction of such systems in any areas independent of the local topography in contrast to the compressed-air energy storage gas-turbine plants, which require large-sized underground reservoirs. It should be noted that, during the energy recovery, the air that arrives from the reservoir is heated by combustion of hydrogen in oxygen, which results in the gas-turbine exhaust gases practically free of substances hazardous to the health and the environment. The results of analysis of a hydrogen-air energy storage gas-turbine system are presented. Its layout and the principle of its operation are described and the basic parameters are computed. The units of the system are analyzed and their costs are assessed; the recovery factor is estimated at more than 60%. According to the obtained results, almost all main components of the hydrogen-air energy storage gas-turbine system are well known at present; therefore, no considerable R&D costs are required. A new component of the system is the H2-O2 combustion chamber; a difficulty in manufacturing it is the necessity of ensuring the combustion of hydrogen in oxygen as complete as possible and preventing formation of nitric oxides.

  11. Air and spaceborne radar systems an introduction

    CERN Document Server

    Lacomme, Philippe; Hardange, Jean-Philippe; Normant, Eric

    2001-01-01

    A practical tool on radar systems that will be of major help to technicians, student engineers and engineers working in industry and in radar research and development. The many users of radar as well as systems engineers and designers will also find it highly useful. Also of interest to pilots and flight engineers and military command personnel and military contractors. """"This introduction to the field of radar is intended for actual users of radar. It focuses on the history, main principles, functions, modes, properties and specific nature of modern airborne radar. The book examines radar's

  12. Systemic air embolism during pleural lavage for empyema.

    Science.gov (United States)

    Ohuchi, Masatsugu; Inoue, Shuhei; Ozaki, Yoshitomo; Ueda, Keiko

    2017-10-01

    Pleural lavage has been considered a convenient and safe method that is often performed for empyema. We report a case of systemic air embolism that developed during pleural lavage. A 53-year-old man with empyema in the organizing phase suddenly developed paralysis of the left side of the body and altered level of consciousness during pleural lavage, which was performed in a sitting position without negative pressure suction. Systemic air embolism was diagnosed based on computed tomography. In this case, use of fibrinolytic agents, positioning during pleural lavage, and pressure in an empyema cavity may have predisposed to development of systemic air embolism. Conversion from thoracoscopic therapy to open decortication or fenestration should be considered to prevent this type of complication.

  13. Analysis and simulation of mobile air conditioning system coupled with engine cooling system

    International Nuclear Information System (INIS)

    Qi, Zhao-gang; Chen, Jiang-ping; Chen, Zhi-jiu

    2007-01-01

    Many components of the mobile air conditioning system and engine cooling system are closely interrelated and make up the vehicle climate control system. In the present paper, a vehicle climate control system model including air conditioning system and engine cooling system has been proposed under different operational conditions. All the components have been modeled on the basis of experimental data. Based on the commercial software, a computer simulation procedure of the vehicle climate control system has been developed. The performance of the vehicle climate control system is simulated, and the calculational data have good agreement with experimental data. Furthermore, the vehicle climate control simulation results have been compared with an individual air conditioning system and engine cooling system. The influences between the mobile air conditioning system and the engine cooling system are discussed

  14. Development of mobile air pollution monitoring system (LIDAR)

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Hyung Ki; Song, Kyu Seok; Kim, Dukh Yeon; Yang, Ki Ho; Lee, Jong Min; Yoon, S.; Rostov, A

    2001-01-01

    Most air pollution monitoring technologies accompany a time-consuming sample treatment and provide pollution information only for a local area. Thus, they have a critical restriction in monitoring time-dependent pollution variation effectively over the wide range of area both in height and in width. LIDAR(Light Detection And Ranging) is a new technology to overcome such drawbacks of the existing pollution monitoring technologies and has long been investigated in the advanced countries. The coal of this project is to develop the mobile air pollution monitoring system and to apply the system to the detection of various pollutants, such as ozone, nitrogen dioxide, sulfur dioxide and aerosols.

  15. Differences in net global warming potential and greenhouse gas intensity between major rice-based cropping systems in China.

    Science.gov (United States)

    Xiong, Zhengqin; Liu, Yinglie; Wu, Zhen; Zhang, Xiaolin; Liu, Pingli; Huang, Taiqing

    2015-12-02

    Double rice (DR) and upland crop-single rice (UR) systems are the major rice-based cropping systems in China, yet differences in net global warming potential (NGWP) and greenhouse gas intensity (GHGI) between the two systems are poorly documented. Accordingly, a 3-year field experiment was conducted to simultaneously measure methane (CH4) and nitrous oxide (N2O) emissions and changes in soil organic carbon (SOC) in oil rape-rice-rice and wheat-rice (representing DR and UR, respectively) systems with straw incorporation (0, 3 and 6 t/ha) during the rice-growing seasons. Compared with the UR system, the annual CH4, N2O, grain yield and NGWP were significantly increased in the DR system, though little effect on SOC sequestration or GHGI was observed without straw incorporation. Straw incorporation increased CH4 emission and SOC sequestration but had no significant effect on N2O emission in both systems. Averaged over the three study years, straw incorporation had no significant effect on NGWP and GHGI in the UR system, whereas these parameters were greatly increased in the DR system, i.e., by 108% (3 t/ha) and 180% (6 t/ha) for NGWP and 103% (3 t/ha) and 168% (6 t/ha) for GHGI.

  16. Measured Air Distribution Effectiveness for Residential Mechanical Ventilation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sherman, Max; Sherman, Max H.; Walker, Iain S.

    2008-05-01

    The purpose of ventilation is dilute or remove indoor contaminants that an occupant is exposed to. In a multi-zone environment such as a house, there will be different dilution rates and different source strengths in every zone. Most US homes have central HVAC systems, which tend to mix the air thus the indoor conditions between zones. Different types of ventilation systems will provide different amounts of exposure depending on the effectiveness of their air distribution systems and the location of sources and occupants. This paper will report on field measurements using a unique multi-tracer measurement system that has the capacity to measure not only the flow of outdoor air to each zone, but zone-to-zone transport. The paper will derive seven different metrics for the evaluation of air distribution. Measured data from two homes with different levels of natural infiltration will be used to evaluate these metrics for three different ASHRAE Standard 62.2 compliant ventilation systems. Such information can be used to determine the effectiveness of different systems so that appropriate adjustments can be made in residential ventilation standards such as ASHRAE Standard 62.2.

  17. Pulse Detonation Engine Air Induction System Analysis

    Science.gov (United States)

    Pegg, R. J.; Hunter, L. G.; Couch, B. D.

    1996-01-01

    A preliminary mixed-compression inlet design concept for potential pulse-detonation engine (PDE) powered supersonic aircraft was defined and analyzed. The objectives of this research were to conceptually design and integrate an inlet/PDE propulsion system into a supersonic aircraft, perform time-dependent CFD analysis of the inlet flowfield, and to estimate the installed PDE cycle performance. The study was baselined to a NASA Mach 5 Waverider study vehicle in which the baseline over/under turboramjet engines were replaced with a single flowpath PDE propulsion system. As much commonality as possible was maintained with the baseline configuration, including the engine location and forebody lines. Modifications were made to the inlet system's external ramp angles and a rotating cowl lip was incorporated to improve off-design inlet operability and performance. Engines were sized to match the baseline vehicle study's ascent trajectory thrust requirement at Mach 1.2. The majority of this study was focused on a flight Mach number of 3.0. The time-dependent Navier Stokes CFD analyses of a two-dimensional approximation of the inlet was conducted for the Mach 3.0 condition. The Lockheed Martin Tactical Aircraft Systems-developed FALCON CFD code with a two equation 'k-1' turbulence model was used. The downstream PDE was simulated by an array of four sonic nozzles in which the flow areas were rapidly varied in various opening/closing combinations. Results of the CFD study indicated that the inlet design concept operated successfully at the Mach 3.0 condition, satisfying mass capture, total pressure recovery, and operability requirements. Time-dependent analysis indicated that pressure and expansion waves from the simulated valve perturbations did not effect the inlet's operability or performance.

  18. Evaluation of simplified ventilation system with direct air supply through the facade in a school in a cold climate

    Energy Technology Data Exchange (ETDEWEB)

    Mysen, M. [Norwegian Building Research Institute, Blindern, Oslo (Norway); Department of Energy and Process Technology, Norwegian University of Science and Technology (NTNU), Trondheim (Norway); Schild, P. G.; Hellstrand, V.; Thunshelle, K. [Norwegian Building Research Institute, Blindern, Oslo (Norway)

    2004-07-01

    Many educational buildings in industrialised countries have poor indoor climate, according to today's knowledge about the impact of indoor climate on well-being and productivity. Budget restrictions and practical limitations such as lack of space for central air handling units and ventilation ducts, have motivated the application of simplified ventilation systems in some schools, such as taking unconditioned supply air directly from the facade. One such school was recently evaluated in Norway. On cold days, thermal comfort in the classroom deteriorated due to cold down draught from the supply outlet. In addition, moist and fertile conditions for microbiological growth were observed in the air supply ductwork. On the other hand the same pupils are more satisfied with the school and have less sick building syndrome (SBS) symptoms during winter than summer. An improved control strategy with a temperature-compensated CO{sub 2} set-point for controlling the air flow is suggested. This could improve thermal comfort and reduce energy use without compromising perceived air quality (PAQ) during cold weather. Furthermore it could improve indoor air quality (IAQ) during warm weather with only a slight increase of energy use. Further evaluation of an improved solution is needed before such a ventilation concept can be recommended in cold climates. (author)

  19. Importance of food waste pre-treatment efficiency for global warming potential in life cycle assessment of anaerobic digestion systems

    DEFF Research Database (Denmark)

    Carlsson, My; Naroznova, Irina; Møller, Jacob

    2015-01-01

    treatment of the refuse. The objective of this study was to investigate how FW pre-treatment efficiency impacts the environmental performance of waste management, with respect to global warming potential (GWP). The modeling tool EASETECH was used to perform consequential LCA focusing on the impact...... when biogas and refuse were substituting the same energy carriers, when energy conversion efficiencies were high and slurry quality good enough to enable digestate use on land. In these cases other environmental aspects, economy and practicality could be guiding when selecting pre-treatment system......A need for improvement of food waste (FIAT) pre-treatment methods has been recognized, but few life cycle assessments (LCA) of FIN management systems have considered the pre-treatment with respect to input energy, loss of organic material and nutrients for anaerobic digestion (AD) and/or further...

  20. A new compressed air energy storage refrigeration system

    International Nuclear Information System (INIS)

    Wang Shenglong; Chen Guangming; Fang Ming; Wang Qin

    2006-01-01

    In this study, a new compressed air energy storage (CAES) refrigeration system is proposed for electrical power load shifting application. It is a combination of a gas refrigeration cycle and a vapor compression refrigeration cycle. Thermodynamic calculations are conducted to investigate the performance of this system. Economic analysis is performed to study the operating cost of the system, and comparison is made with a vapor compression refrigeration system and an ice storage refrigeration system. The results indicate that the CAES refrigeration system has the advantages of simple structure, high efficiency and low operating cost

  1. Adaptation to a warming-drying trend through cropping system adjustment over three decades: A case study in the northern agro-pastural ecotone of China

    Science.gov (United States)

    Zhang, Jingting; An, Pingli; Pan, Zhihua; Hao, Baozhen; Wang, Liwei; Dong, Zhiqiang; Pan, Xuebiao; Xue, Qingwu

    2015-06-01

    Long-term field monitoring data and historical crop data are useful to assess the impacts of climate change and to manage cropping systems. The objectives of this study are to understand the cropping system response to a warming-drying trend in the northern agro-pastural ecotone (NAE) of China and to document how farmers can adapt to the warming-drying trend by changing cropping system structure and adjusting planting date. The results indicate that a significant warming-drying trend existed in the NAE from 1980 to 2009, and this trend significantly decreased crop (spring wheat, naked oat, and potato) yields. Furthermore, the yield decreased by 16.2%-28.4% with a 1°C increase in maximum temperature and decreased by 6.6%-11.8% with a 10% decrease in precipitation. Considering food security, water use efficiency, and water ecological adaptability in the semi-arid NAE, cropping system structure adjustment (e.g., a shift from wheat to potato as the predominant crop) and planting date adaptation (e.g., a delay in crop planting date) can offset the impact of the warming-drying trend in the NAE. Based on the successful offsetting of the impact of the warming-drying trend in the NAE, we conclude that farmers can reduce the negative effects of climate change and minimize the risk of crop failure by adapting their cropping system structure at the farming level.

  2. Demand control on room level of the supply air temperature in an air heating and ventilation system

    DEFF Research Database (Denmark)

    Polak, Joanna; Afshari, Alireza; Bergsøe, Niels Christian

    2017-01-01

    The aim of this study was to investigate a new strategy for control of supply air temperature in an integrated air heating and ventilation system. The new strategy enables demand control of supply air temperature in individual rooms. The study is based on detailed dynamic simulations of a combined...

  3. The use of an air filtration system in podiatry clinics.

    Science.gov (United States)

    McLarnon, Nichola; Burrow, Gordon; Maclaren, William; Aidoo, Kofi; Hepher, Mike

    2003-06-01

    A small-scale study was conducted to ascertain the efficiency and effectiveness of an air filtration system for use in podiatry/chiropody clinics (Electromedia Model 35F (A), Clean Air Ltd, Scotland, UK). Three clinics were identified, enabling comparison of data between podiatry clinics in the West of Scotland. The sampling was conducted using a portable Surface Air Sampler (Cherwell Laboratories, Bicester, UK). Samples were taken on two days at three different times before and after installation of the filtration units. The global results of the study indicate the filter has a statistically significant effect on microbial counts, with an average percentage decrease of 65%. This study is the first time, to the authors' knowledge, such a system has been tested within podiatric practice.

  4. Improved fireman's compressed air breathing system pressure vessel development program

    Science.gov (United States)

    King, H. A.; Morris, E. E.

    1973-01-01

    Prototype high pressure glass filament-wound, aluminum-lined pressurant vessels suitable for use in a fireman's compressed air breathing system were designed, fabricated, and acceptance tested in order to demonstrate the feasibility of producing such high performance, lightweight units. The 4000 psi tanks have a 60 standard cubic foot (SCF) air capacity, and have a 6.5 inch diamter, 19 inch length, 415 inch volume, weigh 13 pounds when empty, and contain 33 percent more air than the current 45 SCF (2250 psi) steel units. The current steel 60 SCF (3000 psi) tanks weigh approximately twice as much as the prototype when empty, and are 2 inches, or 10 percent shorter. The prototype units also have non-rusting aluminum interiors, which removes the hazard of corrosion, the need for internal coatings, and the possibility of rust particles clogging the breathing system.

  5. Merging Air Quality and Public Health Decision Support Systems

    Science.gov (United States)

    Hudspeth, W. B.; Bales, C. L.

    2003-12-01

    The New Mexico Air Quality Mapper (NMAQM) is a Web-based, open source GIS prototype application that Earth Data Analysis Center is developing under a NASA Cooperative Agreement. NMAQM enhances and extends existing data and imagery delivery systems with an existing Public Health system called the Rapid Syndrome Validation Project (RSVP). RSVP is a decision support system operating in several medical and public health arenas. It is evolving to ingest remote sensing data as input to provide early warning of human health threats, especially those related to anthropogenic atmospheric pollutants and airborne pathogens. The NMAQM project applies measurements of these atmospheric pollutants, derived from both remotely sensed data as well as from in-situ air quality networks, to both forecasting and retrospective analyses that influence human respiratory health. NMAQM provides a user-friendly interface for visualizing and interpreting environmentally-linked epidemiological phenomena. The results, and the systems made to provide the information, will be applicable not only to decision-makers in the public health realm, but also to air quality organizations, demographers, community planners, and other professionals in information technology, and social and engineering sciences. As an accessible and interactive mapping and analysis application, it allows environment and health personnel to study historic data for hypothesis generation and trend analysis, and then, potentially, to predict air quality conditions from daily data acquisitions. Additional spin off benefits to such users include the identification of gaps in the distribution of in-situ monitoring stations, the dissemination of air quality data to the public, and the discrimination of local vs. more regional sources of air pollutants that may bear on decisions relating to public health and public policy.

  6. Analysis on a hybrid desiccant air-conditioning system

    International Nuclear Information System (INIS)

    Jia, C.X.; Dai, Y.J.; Wu, J.Y.; Wang, R.Z.

    2006-01-01

    Hybrid desiccant-assisted preconditioner and split cooling coil system, which combines the merits of moisture removal by desiccant and cooling coil for sensible heat removal, is a potential alternative to conventional vapor compression cooling systems. In this paper, experiments on a hybrid desiccant air-conditioning system, which is actually an integration of a rotary solid desiccant dehumidification and a vapor compression air-conditioning unit, had been carried out. It is found that, compared with the conventional VC (vapor compression) system, the hybrid desiccant cooling system economizes 37.5% electricity powers when the process air temperature and relative humidity are maintained at 30 o C, and 55% respectively. The reason why the hybrid desiccant cooling system features better performance relative to the VC system lies in the improvement brought about in the performance of the evaporator in VC unit due to desiccant dehumidification. A thermodynamic model of the hybrid desiccant system with R-22 as the refrigerant has been developed and the impact of operating parameters on the sensible heat ratio of the evaporator and the electric power saving rate has been analyzed. It is found that a majority of evaporators can operate in the dry condition even if the regeneration temperature is lower (i.e. 80 o C)

  7. Design of Air Traffic Control Operation System

    Directory of Open Access Journals (Sweden)

    Gabriela STROE

    2017-09-01

    Full Text Available This paper presents a numerical simulation for a different aircraft, based on the specific aircraft data that can be incorporated in the model and the equations of motions which can be consequently solved. The aircraft flight design involves various technical steps and requires the use of sophisticated software having modeling and simulation capabilities. Within the flight simulation model, the aerodynamic model can be regarded as the most complex and most important. With appropriate aerodynamic modeling the aerodynamic forces and moments acting on the aircraft's center of gravity can be numerically solved with accuracy. These forces and moments are further used to solve the equations of motion. The development of control and computing technology makes it possible for advanced flight control strategy. The advanced control techniques tend to make the control design and their implementation much more complicated with more control loops or channels; in this line, the autopilot of modern aircrafts includes a variety of automatic control systems that aid and support the flight navigation, flight management, and perform the enhancing and/or augmenting of the stability characteristics of the airplane. Therefore in this context it is very important to choose the dynamic that will satisfy the performance and robustness specifications.

  8. The ''Nuclear-Karlsruhe'' air-filter system

    International Nuclear Information System (INIS)

    Berliner, P.; Ohlmeyer, M.; Stotz, W.

    1976-01-01

    Increasing requirements for exhaust-air filter systems used in nuclear facilities induced the Gesellschaft fuer Kernforschung to develop the ''Nuclear-Karlsruhe'' HEPA filter system. This novel development has profited by experience gained in previous incidents as well as by maitenance and decontamination work performed with different HEPA filter systems. The proved ''Nuclear-Karlsruhe'' system takes equally into account the demands for optimum safety, maximum efficiency and economy, and is distinguished by the following features: (1) The air current is defected by 180 0 in the casing. Deflection causes quite a number of improvements, results in substantial reduction of space requirements, and avoids the dispersion of pollutants to the clean-air side. Besides, the HEPA filter is protected from damage by condensed particles or foreign materials entrained; (2) The ''Nuclear-Karlsruhe'' system allows gas-tight filter replacement. Special replacement collars have been provided at the casing, which allow the tight fastening of replacement bags which are self-locking. (3) In-place testing in the operating condition can be carried out very conveniently because the air is deflected. Minimum leaks in the filter medium or in the filter gasket can be detected by the high-sensitivity visual oil-thread test, which makes leaks distinctly visible as oil mist threads through a transparent front window provided on the clean-air side. The test takes only some minutes and its sensitivity is hardly matched by any other technique. (4) The clamping mechanism is installed outside the casing, i.e. outside the polluted or aggressive media. The contact force is spring-loaded absolutely uniformly to the circular filter gasket. (5) For practical and econmic reasons the filter casings can be locked individually so as to be gas-tight. (6) The entire system is made of stainless or coated steel and metal parts which are corrosion and fire-resistant. (author)

  9. New Compressor Added to Glenn's 450- psig Combustion Air System

    Science.gov (United States)

    Swan, Jeffrey A.

    2000-01-01

    In September 1999, the Central Process Systems Engineering Branch and the Maintenance and the Central Process Systems Operations Branch, released for service a new high pressure compressor to supplement the 450-psig Combustion Air System at the NASA Glenn Research Center at Lewis Field. The new compressor, designated C-18, is located in Glenn s Central Air Equipment Building and is remotely operated from the Central Control Building. C-18 can provide 40 pounds per second (pps) of airflow at pressure to our research customers. This capability augments our existing system capacity (compressors C 4 at 38 pps and C-5 at 32 pps), which is generated from Glenn's Engine Research Building. The C-18 compressor was originally part of Glenn's 21-Inch Hypersonic Tunnel, which was transferred from the Jet Propulsion Laboratory to Glenn in the mid-1980's. With the investment of construction of facilities funding, the compressor was modified, new mechanical and electrical support equipment were purchased, and the unit was installed in the basement of the Central Air Equipment Building. After several weeks of checkout and troubleshooting, the new compressor was ready for long-term, reliable operations. With a total of 110 pps in airflow now available, Glenn is well positioned to support the high-pressure air test requirements of our research customers.

  10. AIRS FPA applied to the MIRIADS: powerful infrared systems applications

    Science.gov (United States)

    Caulfield, John T.; McCarley, Paul L.; Baxter, Christopher R.; Massie, Mark A.

    2001-10-01

    Raytheon's Infrared Operations (RIO) has invented and developed a new type of focal plane array with 'Image Processing on-the-chip' named the Adaptive IR Sensor (AIRS). The AIRS FPA is based upon the human retina in that it performs signal processing near the photoreceptors. The AIRS FPA has been reduced to practice and adaptively removes detector and optic temperature drift and 1/f induced fixed pattern noise. This 3rd-generation multi-mode IRFPA, also called a Smart FPA, is a 256 X 256-array format capable of operation in four modes: (1) Direct Injection (DI), (2) Adaptive Non-uniformity Correction (NUC), (3) Motion/Edge Detection, and (4) Subframe Averaging. Nova Research has developed a Modular IR Application Development System (MIRIADS) which is a compact single board camera system that is highly integrated with the dewar assembly. The MIRIADS system coupled with the AIRS Smart FPA results in a very high performance wide field of view IR Sensor and processing system with integrated in one of the smallest packages to date.

  11. Computational fluid dynamics for turbomachinery internal air systems.

    Science.gov (United States)

    Chew, John W; Hills, Nicholas J

    2007-10-15

    Considerable progress in development and application of computational fluid dynamics (CFD) for aeroengine internal flow systems has been made in recent years. CFD is regularly used in industry for assessment of air systems, and the performance of CFD for basic axisymmetric rotor/rotor and stator/rotor disc cavities with radial throughflow is largely understood and documented. Incorporation of three-dimensional geometrical features and calculation of unsteady flows are becoming commonplace. Automation of CFD, coupling with thermal models of the solid components, and extension of CFD models to include both air system and main gas path flows are current areas of development. CFD is also being used as a research tool to investigate a number of flow phenomena that are not yet fully understood. These include buoyancy-affected flows in rotating cavities, rim seal flows and mixed air/oil flows. Large eddy simulation has shown considerable promise for the buoyancy-driven flows and its use for air system flows is expected to expand in the future.

  12. Cost analysis of hot-air solar-heating systems

    Science.gov (United States)

    Hawkins, B. J.; Stewart, R. D.

    1979-01-01

    Report describes results of study of two operational test sites (Huntsville, Alabama and Carlsbad, New Mexico) furnishing stimates of actual costs and potential cost savings of new and retrofit hot-air solar heating and hot-water system for single family dwellings.

  13. Prototype Systems for Measuring Outdoor Air Intake Rates in Rooftop Air Handlers

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Chan, Wanyu R. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hotchi, Toshifumi [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2015-01-01

    The widespread absence of systems for real-time measurement and feedback control, of minimum outdoor air intake rates in HVAC systems contributes to the poor control of ventilation rates in commercial buildings. Ventilation rates affect building energy consumption and influence occupant health. The project designed fabricated and tested four prototypes of systems for measuring rates of outdoor air intake into roof top air handlers. All prototypes met the ±20% accuracy target at low wind speeds, with all prototypes accurate within approximately ±10% after application of calibration equations. One prototype met the accuracy target without a calibration. With two of four prototype measurement systems, there was no evidence that wind speed or direction affected accuracy; however, winds speeds were generally below usually 3.5 m s-1 (12.6 km h-1) and further testing is desirable. The airflow resistance of the prototypes was generally less than 35 Pa at maximum RTU air flow rates. A pressure drop of this magnitude will increase fan energy consumption by approximately 4%. The project did not have resources necessary to estimate costs of mass produced systems. The retail cost of components and materials used to construct prototypes ranged from approximately $1,200 to $1,700. The test data indicate that the basic designs developed in this project, particularly the designs of two of the prototypes, have considerable merit. Further design refinement, testing, and cost analysis would be necessary to fully assess commercial potential. The designs and test results will be communicated to the HVAC manufacturing community.

  14. AQUIS: An air quality and permit information management system

    Energy Technology Data Exchange (ETDEWEB)

    Smith, A.E.; Huber, C.C.; Tschanz, J. (Argonne National Lab., IL (USA)); Ryckman, S.J. Jr. (Air Force Logistics Command, Wright-Patterson AFB, OH (USA))

    1991-01-01

    The Air Quality Utility Information System (AQUIS) is a data base management system that operates on a dedicated, IBM-compatible personal computer using dBASE IV. AQUIS is in operation at six of the seven US Air Force Logistics Command (AFLC) bases to assist with the management of the source inventory, permit tracking, and the estimating and tracking of emissions. The system also provides environmental management personnel with information on regulatory requirements and other compliance information. An AFLC base can have over 500 regulated or unregulated emission sources, and the task of tracking and correlating emissions, sources, and permits is substantial. AQUIS is a comprehensive management tool that provides a single system for storing and accessing information previously available only in multiple, uncorrelated files. This paper discusses the development of the system and provides an overview of the system structure and the relationship of that structure to sources in the field. Certain features such as the linking capability and compound-specific emissions are highlighted. The experience of environmental managers, the ultimate system users, is discussed, including specific ways in which AQUIS has proven useful in responding to managers' needs for air quality information. 10 refs., 3 figs., 1 tab.

  15. Development of Low Global Warming Potential Refrigerant Solutions for Commercial Refrigeration Systems using a Life Cycle Climate Performance Design Tool

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Fricke, Brian A [ORNL; Vineyard, Edward Allan [ORNL

    2012-01-01

    Commercial refrigeration systems are known to be prone to high leak rates and to consume large amounts of electricity. As such, direct emissions related to refrigerant leakage and indirect emissions resulting from primary energy consumption contribute greatly to their Life Cycle Climate Performance (LCCP). In this paper, an LCCP design tool is used to evaluate the performance of a typical commercial refrigeration system with alternative refrigerants and minor system modifications to provide lower Global Warming Potential (GWP) refrigerant solutions with improved LCCP compared to baseline systems. The LCCP design tool accounts for system performance, ambient temperature, and system load; system performance is evaluated using a validated vapor compression system simulation tool while ambient temperature and system load are devised from a widely used building energy modeling tool (EnergyPlus). The LCCP design tool also accounts for the change in hourly electricity emission rate to yield an accurate prediction of indirect emissions. The analysis shows that conventional commercial refrigeration system life cycle emissions are largely due to direct emissions associated with refrigerant leaks and that system efficiency plays a smaller role in the LCCP. However, as a transition occurs to low GWP refrigerants, the indirect emissions become more relevant. Low GWP refrigerants may not be suitable for drop-in replacements in conventional commercial refrigeration systems; however some mixtures may be introduced as transitional drop-in replacements. These transitional refrigerants have a significantly lower GWP than baseline refrigerants and as such, improved LCCP. The paper concludes with a brief discussion on the tradeoffs between refrigerant GWP, efficiency and capacity.

  16. AUTOMOTIVE DIESEL MAINTENANCE 1. UNIT II, MAINTAINING THE AIR SYSTEM--DETROIT DIESEL ENGINES.

    Science.gov (United States)

    Human Engineering Inst., Cleveland, OH.

    THIS MODULE OF A 30-MODULE COURSE IS DESIGNED TO DEVELOP AN UNDERSTANDING OF THE OPERATION AND MAINTENANCE OF THE DIESEL ENGINE AIR SYSTEM. TOPICS ARE (1) OPERATION AND FUNCTION, (2) AIR CLEANER, (3) AIR SHUT-DOWN HOUSING, (4) EXHAUST SYSTEM, (5) BLOWER, (6) TURBOCHARGER, AND (7) TROUBLE-SHOOTING TIPS ON THE AIR SYSTEM. THE MODULE CONSISTS OF A…

  17. 77 FR 15813 - Preoperational Testing of Instrument and Control Air Systems

    Science.gov (United States)

    2012-03-16

    ... COMMISSION Preoperational Testing of Instrument and Control Air Systems AGENCY: Nuclear Regulatory Commission..., ``Preoperational Testing of Instrument and Control Air Systems.'' This regulatory guide is being revised to address... instrument and control air systems (ICAS) to meet seismic requirement, ICAS air-dryer testing to meet dew...

  18. Newly Discovered Silicate Features in the Spectra of Young Warm Debris Disks: Probing Terrestrial Regions of Planetary Systems

    Science.gov (United States)

    Ballering, N.; Rieke, G.

    2014-03-01

    Terrestrial planets form by the collisional accretion of planetesimals during the first 100 Myr of a system’s lifetime. For most systems, the terrestrial regions are too near their host star to be directly seen with high-contrast imaging (e.g. with HST, MagAO, or LBTI) and too warm to be imaged with submillimeter interferometers (e.g. ALMA). Mid-infrared excess spectra—originating from the thermal emission of the circumstellar dust leftover from these collisions—remain the best data to constrain the properties of the debris in these regions. The spectra of most debris disks are featureless, taking the shape of (modified) blackbodies. Determining the properties of debris disks with featureless spectra is complicated by a degeneracy between the grain size and location (large grains near the star and small grains farther from the star may be indistinguishable). Debris disk spectra that exhibit solid state emission features allow for a more accurate determination of the dust size and location (e.g. Chen et al. 2006; Olofsson et al. 2012). Such features probe small, warm dust grains in the inner regions of these systems where terrestrial planet formation may be proceeding (Lisse et al. 2009). We report here a successful search for such features. We identified our targets with a preliminary search for signs of emission features in the Spitzer IRS spectra of a number of young early type stars known to harbor warm debris disks. We fit to each target a physically-motivated model spectrum consisting of the sum of the stellar photosphere (modeled as a blackbody) and thermal emission from two dust belts. Each belt was defined by 6 parameters: the inner and outer orbital radii (rin and rout), the index of the radial surface density power law (rexp), the minimum and maximum grain sizes (amin and amax), and the index of the grain size distribution power law (aexp). aexp was fixed to -3.65 and amax was fixed to 1000 μm for all models; all other parameters were allowed to

  19. Replacing an electrical heating system by an air/water heat pump; Remplacement du chauffage electrique par une installation PAC air/eau (pompe a chaleur)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-07-01

    A group of thirteen houses in Plan-les-Ouates (southwestern Switzerland) constructed in 1985 was originally equipped with direct electric heaters. Their inhabitants complained about high electricity bills and bad thermal comfort due to uneven room temperatures and insufficient amounts of warm water. A group of specialists from the Swiss Federal Office of Energy, the energy service of the canton of Geneva and from an engineering company studied the case and suggested to replace the direct electric heating system by an air to water heat pump. Seven owners have decided for this modification and the retrofit has been made in autumn 2000. The paper presents the results of performance measurements, operating experience gained and economic considerations for the years 2001, 2002 and 2003 for six installations. The average coefficients of performance ranged from 2.3 to 2.9.

  20. Mathematical model of one-man air revitalization system

    Science.gov (United States)

    1976-01-01

    A mathematical model was developed for simulating the steady state performance in electrochemical CO2 concentrators which utilize (NMe4)2 CO3 (aq.) electrolyte. This electrolyte, which accommodates a wide range of air relative humidity, is most suitable for one-man air revitalization systems. The model is based on the solution of coupled nonlinear ordinary differential equations derived from mass transport and rate equations for the processes which take place in the cell. The boundary conditions are obtained by solving the mass and energy transport equations. A shooting method is used to solve the differential equations.

  1. Developments in skirt systems for air cushion vehicles

    Science.gov (United States)

    Inch, Peter; Prentice, Mark E.; Lewis, Carol Jean

    The present evaluation of the development status of air-cushion vehicle (ACV) skirts emphasizes the materials employed, with a view to the formulation of materials-performance requirements for next-generation AVCs and, in particular, an 'air-cushion catamaran' surface-effect ship (SES). Attention is given to novel skirt-design features which furnish substantial savings in maintenance costs. The employment of extant test rig data and the use of CAD methods are discussed, and the features of a novel system for the direct fixing of a bow finger onto an SES structure are noted.

  2. Urban air quality measurements using a sensor-based system

    Science.gov (United States)

    Ródenas, Mila; Hernández, Daniel; Gómez, Tatiana; López, Ramón; Muñoz, Amalia

    2017-04-01

    Air pollution levels in urban areas have increased the interest, not only of the scientific community but also of the general public, and both at the regional and at the European level. This interest has run in parallel to the development of miniaturized sensors, which only since very recently are suitable for air quality measurements. Certainly, their small size and price allows them to be used as a network of sensors capable of providing high temporal and spatial frequency measurements to characterize an area or city and with increasing potential, under certain considerations, as a complement of conventional methods. Within the frame of the LIFE PHOTOCITYTEX project (use of photocatalytic textiles to help reducing air pollution), CEAM has developed a system to measure gaseous compounds of importance for urban air quality characterization. This system, which allows an autonomous power supply, uses commercial NO, NO2, O3 and CO2 small sensors and incorporates measurements of temperature and humidity. A first version, using XBee boards (Radiofrequency) for communications has been installed in the urban locations defined by the project (tunnel and school), permitting the long-term air quality characterization of sites in the presence of the textiles. An improved second version of the system which also comprises a sensor for measuring particles and which uses GPRS for communications, has been developed and successfully installed in the city center of Valencia. Data are sent to a central server where they can be accessed by citizens in nearly real time and online and, in general, they can be utilized in the air quality characterization, for decision-making related to decontamination (traffic regulation, photocatalytic materials, etc.), in air quality models or in mobile applications of interest for the citizens. Within this work, temporal trends obtained with this system in different urban locations will be shown, discussing the impact of the characteristics of the

  3. CLASSIFICATION OF THE MGR SITE COMPRESSED AIR SYSTEM

    International Nuclear Information System (INIS)

    J.A. Ziegler

    1999-01-01

    The purpose of this analysis is to document the Quality Assurance (QA) classification of the Monitored Geologic Repository (MGR) site compressed air system structures, systems and components (SSCs) performed by the MGR Safety Assurance Department. This analysis also provides the basis for revision of YMP/90-55Q, Q-List (YMP 1998). The Q-List identifies those MGR SSCs subject to the requirements of DOE/RW-0333P, ''Quality Assurance Requirements and Description'' (QARD) (DOE 1998)

  4. Inverse Flush Air Data System (FADS) for Real Time Simulations

    Science.gov (United States)

    Madhavanpillai, Jayakumar; Dhoaya, Jayanta; Balakrishnan, Vidya Saraswathi; Narayanan, Remesh; Chacko, Finitha Kallely; Narayanan, Shyam Mohan

    2017-12-01

    Flush Air Data Sensing System (FADS) forms a mission critical sub system in future reentry vehicles. FADS makes use of surface pressure measurements from the nose cap of the vehicle for deriving the air data parameters of the vehicle such as angle of attack, angle of sideslip, Mach number, etc. These parameters find use in the flight control and guidance systems, and also assist in the overall mission management. The FADS under consideration in this paper makes use of nine pressure ports located in the nose cap of a technology demonstrator vehicle. In flight, the air data parameters are obtained from the FADS estimation algorithm using the pressure data at the nine pressure ports. But, these pressure data will not be available, for testing the FADS package during ground simulation. So, an inverse software to FADS which estimates the pressure data at the pressure ports for a given flight condition is developed. These pressure data at the nine ports will go as input to the FADS package during ground simulation. The software is run to generate the pressure data for the descent phase trajectory of the technology demonstrator. This data is used again to generate the air data parameters from FADS algorithm. The computed results from FADS algorithm match well with the trajectory data.

  5. The system of thermoelectric air conditioning based on permeable thermoelements

    Directory of Open Access Journals (Sweden)

    Cherkez R. G.

    2009-04-01

    Full Text Available There is thermoelectric air conditioner unit on the basis of permeable cooling thermoelements presented. In thermoelectric air conditioner unit the thermoelectric effects and the Joule–Thomson effect have been used for the air stream cooling. There have been described the method of temperature distribution analysis, the determinations of energy conversion power characteristics and design style of permeable thermoelement with maximum coefficient of performance described. The results of computer analysis concerning the application of the thermoelement legs material on the basis of Bi2Te3 have shown the possibility of coefficient of performance increase by a factor of 1,6—1,7 as compared with conventional thermoelectric systems.

  6. Monitoring and analysis of an absorption air-conditioning system

    Energy Technology Data Exchange (ETDEWEB)

    Perez de Vinaspre, M.; Bourouis, M.; Coronas, A. [Centro de Innovacion Tecnologica en Revalorizacion Energetica y Refrigeracion, Tarragona (Spain); Garcia, A.; Soto, V.; Pinazo, J.M. [E.T.S. Ingenieros Industriales, Valencia (Spain)

    2004-09-01

    In the last few years, high-energy consumption due to air-conditioning has led to a growing interest in the efficient use of energy in buildings. Although simulation programs have always been the main tools for analyzing energy in buildings, the reliability of their results is often compromised by a lack of certainty to reflect real conditions. The aim of this work is to monitorize and analyze the thermal behavior of an absorption-based air-conditioning installation of a university building in Tarragona, Spain. The existing monitoring system of the installation has been improved by implementing additional sensors and flow meters. The data has been stored during summer 2002 and used to assess the energy balance of the air-conditioning installation and the operational regime of the absorption chiller. [Author].

  7. Design and Implementation of Automatic Air Flow Rate Control System

    Science.gov (United States)

    Akbar, A.; Saputra, C.; Munir, M. M.; Khairurrijal

    2016-08-01

    Venturimeter is an apparatus that can be used to measure the air flow rate. In this experiment we designed a venturimeter which equipped with a valve that is used to control the air flow rate. The difference of pressure between the cross sections was measured with the differential pressure sensor GA 100-015WD which can calculate the difference of pressures from 0 to 3737.33 Pa. A 42M048C Z36 stepper motor was used to control the valve. The precision of this motor rotation is about 0.15 °. A Graphical User Interface (GUI) was developed to monitor and set the value of flow rate then an 8-bit microcontroller was used to process the control system In this experiment- the venturimeter has been examined to get the optimal parameter of controller. The results show that the controller can set the stable output air flow rate.

  8. Global warming

    CERN Document Server

    Hulme, M

    1998-01-01

    Global warming-like deforestation, the ozone hole and the loss of species- has become one of the late 20the century icons of global environmental damage. The threat, is not the reality, of such a global climate change has motivated governments. businesses and environmental organisations, to take serious action ot try and achieve serious control of the future climate. This culminated last December in Kyoto in the agreement for legally-binding climate protocol. In this series of three lectures I will provide a perspective on the phenomenon of global warming that accepts the scientific basis for our concern, but one that also recognises the dynamic interaction between climate and society that has always exited The future will be no different. The challenge of global warning is not to pretend it is not happening (as with some pressure groups), nor to pretend it threatens global civilisation (as with other pressure groups), and it is not even a challenge to try and stop it from happening-we are too far down the ro...

  9. Hybrid membrane contactor system for creating semi-breathing air

    Science.gov (United States)

    Timofeev, D. V.

    2012-02-01

    Typically, the equipment to create an artificial climate does not involve changing the composition of the respiratory air. In particular in medical institutions assumes the existence of plant of artificial climate and disinfection in operating rooms and intensive care wards. The use of a hybrid membrane-absorption systems for the generation of artificial atmospheres are improving the respiratory system, blood is enriched or depleted of various gases, resulting in increased stamina, there is a better, faster or slower metabolism, improves concentration and memory. Application of the system contributes to easy and rapid recovery after the operation. By adding a special component, with drug activity, air ionization, and adjust its composition, you can create a special, more favorable for patients with the atmosphere. These factors allow for the treatment and rehabilitation of patients and reduce mortality of heavy patients.

  10. Retrofitting Forced Air Combi Systems: A Cold Climate Field Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [NorthernSTAR, St. Paul, MN (United States); Bohac, Dave [NorthernSTAR, St. Paul, MN (United States); McAlpine, Jack [NorthernSTAR, St. Paul, MN (United States); Hewett, Martha [NorthernSTAR, St. Paul, MN (United States)

    2017-06-01

    This project analyzed combined condensing water heaters or boilers and hydronic air coils to provide high efficiency domestic hot water (DHW) and forced air space heating. Called "combi" systems, they provided similar space and water heating performance less expensively than installing two condensing appliances. The system's installed costs were cheaper than installing a condensing furnace and either a condensing tankless or condensing storage water heater. However, combi costs must mature and be reduced before they are competitive with a condensing furnace and power vented water heater (energy factor of 0.60). Better insulation and tighter envelopes are reducing space heating loads for new and existing homes. For many homes, decreased space heating loads make it possible for both space and domestic water heating loads to be provided with a single heating plant. These systems can also eliminate safety issues associated with natural draft appliances through the use of one common sealed combustion vent. The combined space and water heating approach was not a new idea. Past systems have used non-condensing heating plants, which limited their usefulness in climates with high heating loads. Previous laboratory work (Schoenbauer et al. 2012a) showed that proper installation was necessary to achieve condensing with high efficiency appliances. Careful consideration was paid to proper system sizing and minimizing the water temperature returning from the air handling unit to facilitate condensing operation.

  11. Retrofitting Forced Air Combi Systems: A Cold Climate Field Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Schoenbauer, Ben [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Bohac, Dave [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; McAlpine, Jake [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership; Hewett, Martha [Univ. of Minnesota, St. Paul, MN (United States). NorthernSTAR Building America Partnership

    2017-06-23

    This project analyzed combined condensing water heaters or boilers and hydronic air coils to provide high efficiency domestic hot water (DHW) and forced air space heating. Called 'combi' systems, they provided similar space and water heating performance less expensively than installing two condensing appliances. The system's installed costs were cheaper than installing a condensing furnace and either a condensing tankless or condensing storage water heater. However, combi costs must mature and be reduced before they are competitive with a condensing furnace and power vented water heater (energy factor of 0.60). Better insulation and tighter envelopes are reducing space heating loads for new and existing homes. For many homes, decreased space heating loads make it possible for both space and domestic water heating loads to be provided with a single heating plant. These systems can also eliminate safety issues associated with natural draft appliances through the use of one common sealed combustion vent. The combined space and water heating approach was not a new idea. Past systems have used non-condensing heating plants, which limited their usefulness in climates with high heating loads. Previous laboratory work (Schoenbauer et al. 2012a) showed that proper installation was necessary to achieve condensing with high efficiency appliances. Careful consideration was paid to proper system sizing and minimizing the water temperature returning from the air handling unit to facilitate condensing operation.

  12. Climate Change Hysteria and the Supreme Court: The Economic Impact of Global Warming on the U.S. and the Misguided Regulation of Greenhouse Gas Emissions under the Clean Air Act

    OpenAIRE

    Johnston, Jason Scott

    2008-01-01

    In the spring of 2007, the U.S. Supreme Court ruled in Massachusetts v. EPA that the U.S. Environmental Protection Agency (EPA) must promulgate automobile tailpipe C02 emission standards under Section 202 of the Clean Air Act (CAA). American environmentalists hailed the Supreme Court's decision as an important victory in the battle to curb global warming. This article argues to the contrary that: 1) a large body of economic work demonstrates that the likely pattern of costs and benefits from ...

  13. Applied patent RFID systems for building reacting HEPA air ventilation system in hospital operation rooms.

    Science.gov (United States)

    Lin, Jesun; Pai, Jar-Yuan; Chen, Chih-Cheng

    2012-12-01

    RFID technology, an automatic identification and data capture technology to provide identification, tracing, security and so on, was widely applied to healthcare industry in these years. Employing HEPA ventilation system in hospital is a way to ensure healthful indoor air quality to protect patients and healthcare workers against hospital-acquired infections. However, the system consumes lots of electricity which cost a lot. This study aims to apply the RFID technology to offer a unique medical staff and patient identification, and reacting HEPA air ventilation system in order to reduce the cost, save energy and prevent the prevalence of hospital-acquired infection. The system, reacting HEPA air ventilation system, contains RFID tags (for medical staffs and patients), sensor, and reacting system which receives the information regarding the number of medical staff and the status of the surgery, and controls the air volume of the HEPA air ventilation system accordingly. A pilot program was carried out in a unit of operation rooms of a medical center with 1,500 beds located in central Taiwan from Jan to Aug 2010. The results found the air ventilation system was able to function much more efficiently with less energy consumed. Furthermore, the indoor air quality could still keep qualified and hospital-acquired infection or other occupational diseases could be prevented.

  14. New arrangement for the air cleanup system to recover tritium

    International Nuclear Information System (INIS)

    Nishikawa, Masabumi; Takahashi, Kohsaku; Munakata, Kenzo; Fukada, Satoshi; Kotoh, Kenji; Takeishi, Toshiharu

    1997-01-01

    At present, the standard arrangement of the air cleanup system responsible for emergency tritium recovery from room air is a catalytic oxidation bed with a heater followed by an adsorption bed with a cooler. One disadvantage of this arrangement is that trouble with the heater or the cooler could result in a loss of capacity to recover tritium. Another disadvantage of the catalyst-adsorption-bed arrangement is that tritiated water must be recovered with a high decontamination factor after dilution with a large amount of water vapor in the working atmosphere. The performance of a new arrangement for the air cleanup system, which consists of a precious metal catalyst bed preceded by an adsorption bed without heating equipment, is discussed. According to calculations, most of the tritium released to the room air is recovered in the catalyst bed through oxidation, adsorption, and isotope exchange reaction when the new arrangement is applied. The adsorption bed placed before the catalyst bed dehumidifies the process gas to such a degree that the oxidation reaction of tritium in the catalyst bed is not hindered by water vapor. 15 refs., 6 figs., 6 tabs

  15. CO2, the greenhouse effect and global warming: from the pioneering work of Arrhenius and Callendar to today's Earth System Models.

    Science.gov (United States)

    Anderson, Thomas R; Hawkins, Ed; Jones, Philip D

    2016-09-01

    Climate warming during the course of the twenty-first century is projected to be between 1.0 and 3.7°C depending on future greenhouse gas emissions, based on the ensemble-mean results of state-of-the-art Earth System Models (ESMs). Just how reliable are these projections, given the complexity of the climate system? The early history of climate research provides insight into the understanding and science needed to answer this question. We examine the mathematical quantifications of planetary energy budget developed by Svante Arrhenius (1859-1927) and Guy Stewart Callendar (1898-1964) and construct an empirical approximation of the latter, which we show to be successful at retrospectively predicting global warming over the course of the twentieth century. This approximation is then used to calculate warming in response to increasing atmospheric greenhouse gases during the twenty-first century, projecting a temperature increase at the lower bound of results generated by an ensemble of ESMs (as presented in the latest assessment by the Intergovernmental Panel on Climate Change). This result can be interpreted as follows. The climate system is conceptually complex but has at its heart the physical laws of radiative transfer. This basic, or "core" physics is relatively straightforward to compute mathematically, as exemplified by Callendar's calculations, leading to quantitatively robust projections of baseline warming. The ESMs include not only the physical core but also climate feedbacks that introduce uncertainty into the projections in terms of magnitude, but not sign: positive (amplification of warming). As such, the projections of end-of-century global warming by ESMs are fundamentally trustworthy: quantitatively robust baseline warming based on the well-understood physics of radiative transfer, with extra warming due to climate feedbacks. These projections thus provide a compelling case that global climate will continue to undergo significant warming in response

  16. Methods for air cleaning system design and accident analysis

    International Nuclear Information System (INIS)

    Gregory, W.S.; Nichols, B.D.

    1987-01-01

    This paper describes methods, in the form of a handbook and five computer codes, that can be used for nuclear facility air cleaning system design and accident analysis. Four of the codes were developed primarily at the Los Alamos National Laboratory, and one was developed in France. Tools such as these are used to design ventilation systems in the mining industry but do not seem to be commonly used in the nuclear industry. For example, the Nuclear Air Cleaning Handbook is an excellent design reference, but it fails to include information on computer codes that can be used to aid in the design process. These computer codes allow the analyst to use the handbook information to form all the elements of a complete system design. Because these analysis methods are in the form of computer codes they allow the analyst to investigate many alternative designs. In addition, the effects of many accident scenarios on the operation of the air cleaning system can be evaluated. These tools originally were intended for accident analysis, but they have been used mostly as design tools by several architect-engineering firms. The Cray, VAX, and personal computer versions of the codes, an accident analysis handbook, and the codes availability will be discussed. The application of these codes to several design operations of nuclear facilities will be illustrated, and their use to analyze the effect of several accident scenarios also will be described

  17. Development of Fuzzy Logic Control for Vehicle Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Henry Nasution

    2008-08-01

    Full Text Available A vehicle air conditioning system is experimentally investigated. Measurements were taken during the experimental period at a time interval of one minute for a set point temperature of 22, 23 and 24oC with internal heat loads of 0, 1 and 2 kW. The cabin temperature and the speed of the compressor were varied and the performance of the system, energy consumption and energy saving ware analyzed. The main objective of the experimental work is to evaluate the energy saving obtained when the fuzzy logic control (FLC algorithm, through an inverter, continuously regulates the compressor speed. It demonstrates better control of the compressor operation in terms of energy consumption as compared to the control by using a thermostat imposing On/Off cycles on the compressor at the nominal frequency of 50 Hz. The experimental set-up consists of original components from the air conditioning system of a compact passenger vehicle. The experimental results indicate that the proposed technique can save energy and improve indoor comfort significantly for vehicle air conditioning systems compared to the conventional (On/Off control technique.

  18. New research on bioregenerative air/water purification systems

    Science.gov (United States)

    Johnson, Anne H.; Ellender, R. D.; Watkins, Paul J.

    1991-01-01

    For the past several years, air and water purification systems have been developed and used. This technology is based on the combined activities of plants and microorganisms as they function in a natural environment. More recently, researchers have begun to address the problems associated with indoor air pollution. Various common houseplants are currently being evaluated for their abilities to reduce concentrations of volatile organic compounds (VOCS) such as formaldehyde and benzene. With development of the Space Exploration Initiative, missions will increase in duration, and problems with resupply necessitates implementation of regenerative technology. Aspects of bioregenerative technology have been included in a habitat known as the BioHome. The ultimate goal is to use this technology in conjunction with physicochemical systems for air and water purification within closed systems. This study continued the risk assessment of bioregenerative technology with emphasis on biological hazards. In an effort to evaluate the risk for human infection, analyses were directed at enumeration of fecal streptococci and enteric viruses with the BioHome waste water treatment system.

  19. Energy and environmental performance assessment of R744 booster supermarket refrigeration systems operating in warm climates

    DEFF Research Database (Denmark)

    Gullo, Paride; Elmegaard, Brian; Cortella, Giovanni

    2016-01-01

    This paper presents a theoretical comparison among different commercial refrigeration systems in terms of annual energy consumption and environmental impact. Eight configurations were studied: a R744/R134a cascade refrigeration system (baseline), a conventional and an improved R744 booster system...... as on the running modes of a conventional European supermarket. A transition zone, which occurred between sub critical and transcritical operations, was adopted.The results showed that all the enhanced configurations may achieve a comparable energy saving to the one of the baseline in both the selected locations...

  20. 21 CFR 874.3950 - Transcutaneous air conduction hearing aid system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Transcutaneous air conduction hearing aid system... Transcutaneous air conduction hearing aid system. (a) Identification. A transcutaneous air conduction hearing aid... occluding the ear canal. The device consists of an air conduction hearing aid attached to a surgically...

  1. Vein-style air pumping tube and tire system and method of assembly

    Energy Technology Data Exchange (ETDEWEB)

    Benedict, Robert Leon; Gobinath, Thulasiram; Lin, Cheng-Hsiung; Lamgaday, Robin; Losey, Robert Allen; Griffoin, Jean-Claude Patrice Philippe

    2017-01-03

    An air pumping tube and tire system and method of assembling is provided in which a tire groove is formed to extend into a flexing region of a tire sidewall and a complementary air pumping tube inserts into the tire groove. In the green, uncured air pumping tube condition, one or more check valves are assembled into the air pumping tube through access shafts and align with an internal air passageway of the air pumping tube. Plug components of the system enclose the check valves in the air pumping tube and the check valve-containing green air pumping tube is then cured.

  2. USNRC regulatory guidance for engineered safety feature air cleaning systems

    International Nuclear Information System (INIS)

    Bellamy, R.R.

    1991-01-01

    The need for clear, technically appropriate, and easily implementable guidance for the design, testing, and maintenance of nuclear air cleaning systems has long been recognized. Numerous industry consensus standards have been issued and revised over the last 30 years. Guidance has also been published by the US Nuclear Regulatory Commission in the form of regulations, regulatory guides, standard review plans, NUREG documents, and information notices. This paper will summarize the latest revisions to these documents and emphasize Regulatory Guide 1.52, Design, Testing, and Maintenance Criteria for Post-Accident Engineered-Safety-Feature Atmosphere Cleanup System Air Filtration and Adsorption Units of Light-Water-Cooled Nuclear Power Plants, which was last revised in 1978. The USNRC has undertaken a project to revise this regulatory guide, and the status of that revision is highlighted

  3. Effects of global warming on respiratory diseases

    African Journals Online (AJOL)

    Abe Olugbenga

    Effects of global warming on respiratory diseases. 1. 1. *Tanimowo MO and Abiona Oo. Review Article. ABSTRACT. Background: Global warming is a consequence of air pollution resulting in climate change due to trapping of excess greenhouse gases in the earth's atmosphere that affects biodiversity and constitutes a ...

  4. AirNow Information Management System - Global Earth Observation System of Systems Data Processor for Real-Time Air Quality Data Products

    Science.gov (United States)

    Haderman, M.; Dye, T. S.; White, J. E.; Dickerson, P.; Pasch, A. N.; Miller, D. S.; Chan, A. C.

    2012-12-01

    Built upon the success of the U.S. Environmental Protection Agency's (EPA) AirNow program (www.AirNow.gov), the AirNow-International (AirNow-I) system contains an enhanced suite of software programs that process and quality control real-time air quality and environmental data and distribute customized maps, files, and data feeds. The goals of the AirNow-I program are similar to those of the successful U.S. program and include fostering the exchange of environmental data; making advances in air quality knowledge and applications; and building a community of people, organizations, and decision makers in environmental management. In 2010, Shanghai became the first city in China to run this state-of-the-art air quality data management and notification system. AirNow-I consists of a suite of modules (software programs and schedulers) centered on a database. One such module is the Information Management System (IMS), which can automatically produce maps and other data products through the use of GIS software to provide the most current air quality information to the public. Developed with Global Earth Observation System of Systems (GEOSS) interoperability in mind, IMS is based on non-proprietary standards, with preference to formal international standards. The system depends on data and information providers accepting and implementing a set of interoperability arrangements, including technical specifications for collecting, processing, storing, and disseminating shared data, metadata, and products. In particular, the specifications include standards for service-oriented architecture and web-based interfaces, such as a web mapping service (WMS), web coverage service (WCS), web feature service (WFS), sensor web services, and Really Simple Syndication (RSS) feeds. IMS is flexible, open, redundant, and modular. It also allows the merging of data grids to create complex grids that show comprehensive air quality conditions. For example, the AirNow Satellite Data Processor

  5. Air pollution control system research: An iterative approach to developing affordable systems

    Science.gov (United States)

    Watt, Lewis C.; Cannon, Fred S.; Heinsohn, Robert J.; Spaeder, Timothy A.

    1995-01-01

    This paper describes a Strategic Environmental Research and Development Program (SERDP) funded project led jointly by the Marine Corps Multi-Commodity Maintenance Centers, and the Air and Energy Engineering Research Laboratory (AEERL) of the USEPA. The research focuses on paint booth exhaust minimization using recirculation, and on volatile organic compound (VOC) oxidation by the modules of a hybrid air pollution control system. The research team is applying bench, pilot and full scale systems to accomplish the goals of reduced cost and improved effectiveness of air treatment systems for paint booth exhaust.

  6. Development of an air heating system for single family housing

    DEFF Research Database (Denmark)

    Afshari, Alireza; Gunner, Amalie; Nikolaisen, Christian Grønborg

    2017-01-01

    The initial objective of the project was to break with common thinking about Space heating and to document that air heating can be used as the sole source of heating in a single Family house. The basic idea is that the ventilation must be installed in any case and it may equally well form the heat...... source of the house - Thus the waterborne heating system can be eliminated....

  7. Sensor Deployment for Air Pollution Monitoring Using Public Transportation System

    OpenAIRE

    Yu, James J. Q.; Li, Victor O. K.; Lam, Albert Y. S.

    2015-01-01

    Air pollution monitoring is a very popular research topic and many monitoring systems have been developed. In this paper, we formulate the Bus Sensor Deployment Problem (BSDP) to select the bus routes on which sensors are deployed, and we use Chemical Reaction Optimization (CRO) to solve BSDP. CRO is a recently proposed metaheuristic designed to solve a wide range of optimization problems. Using the real world data, namely Hong Kong Island bus route data, we perform a series of simulations an...

  8. Control of Future Air Traffic Systems via Complexity Bound Management

    Science.gov (United States)

    Alexandrov, Natalia

    2013-01-01

    The complexity of the present system for managing air traffic has led to "discreteness" in approaches to creating new concepts: new concepts are created as point designs, based on experience, expertise, and creativity of the proposer. Discrete point designs may be highly successful but they are difficult to substantiate in the face of equally strong substantiation of competing concepts, as well as the state of the art in concept evaluation via simulations. Hybrid concepts may present a compromise - the golden middle. Yet a hybrid of sometimes in principle incompatible concepts forms another point design that faces the challenge of substantiation and validation. We are faced with the need to re-design the air transportation system ab initio. This is a daunting task, especially considering the problem of transitioning from the present system to any fundamentally new system. However, design from scratch is also an opportunity to reconsider approaches to new concept development. In this position paper we propose an approach, Optimized Parametric Functional Design, for systematic development of concepts for management and control of airspace systems, based on optimization formulations in terms of required system functions and states. This reasoning framework, realizable in the context of ab initio system design, offers an approach to deriving substantiated airspace management and control concepts. With growing computational power, we hope that the approach will also yield a methodology for actual dynamic control of airspace

  9. Late quaternary slip-rate variations along the Warm Springs Valley fault system, northern Walker Lane, California-Nevada border

    Science.gov (United States)

    Gold, Ryan; dePolo, Craig; Briggs, Richard W.; Crone, Anthony

    2013-01-01

    The extent to which faults exhibit temporally varying slip rates has important consequences for models of fault mechanics and probabilistic seismic hazard. Here, we explore the temporal behavior of the dextral‐slip Warm Springs Valley fault system, which is part of a network of closely spaced (10–20 km) faults in the northern Walker Lane (California–Nevada border). We develop a late Quaternary slip record for the fault using Quaternary mapping and high‐resolution topographic data from airborne Light Distance and Ranging (LiDAR). The faulted Fort Sage alluvial fan (40.06° N, 119.99° W) is dextrally displaced 98+42/-43 m, and we estimate the age of the alluvial fan to be 41.4+10.0/-4.8 to 55.7±9.2  ka, based on a terrestrial cosmogenic 10Be depth profile and 36Cl analyses on basalt boulders, respectively. The displacement and age constraints for the fan yield a slip rate of 1.8 +0.8/-0.8 mm/yr to 2.4 +1.2/-1.1 mm/yr (2σ) along the northern Warm Springs Valley fault system for the past 41.4–55.7 ka. In contrast to this longer‐term slip rate, shorelines associated with the Sehoo highstand of Lake Lahontan (~15.8  ka) adjacent to the Fort Sage fan are dextrally faulted at most 3 m, which limits a maximum post‐15.8 ka slip rate to 0.2  mm/yr. These relations indicate that the post‐Lahontan slip rate on the fault is only about one‐tenth the longer‐term (41–56 ka) average slip rate. This apparent slip‐rate variation may be related to co‐dependent interaction with the nearby Honey Lake fault system, which shows evidence of an accelerated period of mid‐Holocene earthquakes.

  10. Variable oxygen/nitrogen enriched intake air system for internal combustion engine applications

    Science.gov (United States)

    Poola, Ramesh B.; Sekar, Ramanujam R.; Cole, Roger L.

    1997-01-01

    An air supply control system for selectively supplying ambient air, oxygen enriched air and nitrogen enriched air to an intake of an internal combustion engine includes an air mixing chamber that is in fluid communication with the air intake. At least a portion of the ambient air flowing to the mixing chamber is selectively diverted through a secondary path that includes a selectively permeable air separating membrane device due a differential pressure established across the air separating membrane. The permeable membrane device separates a portion of the nitrogen in the ambient air so that oxygen enriched air (permeate) and nitrogen enriched air (retentate) are produced. The oxygen enriched air and the nitrogen enriched air can be selectively supplied to the mixing chamber or expelled to atmosphere. Alternatively, a portion of the nitrogen enriched air can be supplied through another control valve to a monatomic-nitrogen plasma generator device so that atomic nitrogen produced from the nitrogen enriched air can be then injected into the exhaust of the engine. The oxygen enriched air or the nitrogen enriched air becomes mixed with the ambient air in the mixing chamber and then the mixed air is supplied to the intake of the engine. As a result, the air being supplied to the intake of the engine can be regulated with respect to the concentration of oxygen and/or nitrogen.

  11. Aviation System Analysis Capability Air Carrier Investment Model-Cargo

    Science.gov (United States)

    Johnson, Jesse; Santmire, Tara

    1999-01-01

    The purpose of the Aviation System Analysis Capability (ASAC) Air Cargo Investment Model-Cargo (ACIMC), is to examine the economic effects of technology investment on the air cargo market, particularly the market for new cargo aircraft. To do so, we have built an econometrically based model designed to operate like the ACIM. Two main drivers account for virtually all of the demand: the growth rate of the Gross Domestic Product (GDP) and changes in the fare yield (which is a proxy of the price charged or fare). These differences arise from a combination of the nature of air cargo demand and the peculiarities of the air cargo market. The net effect of these two factors are that sales of new cargo aircraft are much less sensitive to either increases in GDP or changes in the costs of labor, capital, fuel, materials, and energy associated with the production of new cargo aircraft than the sales of new passenger aircraft. This in conjunction with the relatively small size of the cargo aircraft market means technology improvements to the cargo aircraft will do relatively very little to spur increased sales of new cargo aircraft.

  12. A radioactive aerosols in air monitoring system - 'ASIA'

    International Nuclear Information System (INIS)

    Belaish, I.; Levinson, S.; Pelled, O.; German, U.; Laichter, Y.; Gonen, E.; Wengrowicz, U.; Tirosh, D.; Barak, D.

    1997-01-01

    A continuous air monitoring system called 'ASIA' (Aerosols Sampler In Air) was developed at the NRCN for monitoring and measuring the concentration of airborne alpha emitting radionuclides such as Radon or natural Uranium. The 'ASIA' is a stationary multi-channel analyzer based system. The air passes through a 2.5 cm diameter filter and the radioactivity accumulated on it is monitored by a Silicon solid state detector. The sampling unit can be separated from the display and control unit to enable environment sampling close to the workers. The ASIA uses modern hardware and software in order to improve noise and background reduction and to allow friendly and flexible use. Remote communication is also available. The spectrum and additional data are displayed on line. The system was checked according to ANSI N42.17B -1989. The linearity and efficiency were evaluated by using various alpha sources. The Minimum Detectable Activity (MDA) and Decision Limit (Lc) were calculated according to ANSI N13.30. Long time stability measurements were performed using a natural Uranium source. (authors)

  13. First use of ECOSIM in air management system

    International Nuclear Information System (INIS)

    Perez Vara, R.; Torroglosa Ponce, V.; Lebru, A.; Novara, M.

    1993-01-01

    ECOSIM is a software tool for the simulation of Environmental Control and Life Support (ECLS) systems which has been developed for the European Space Agency. A preliminary model of the Hermes Air Management System has been developed during the ECOSIM testing in order to assess the functionality of the software and to verify its results with those obtained from previous simulation tools. The model represents the Hermes cabin with its crew and it includes submodels for the sub-systems performing the following functions: - Temperature and Humidity Control; - Total Pressure and Composition Control; - Air revitalisation. The interactions between these different subsystem are taken into account by the model, while many of the previous simulations made assumptions to decouple the different subsystems (e.g: a constant cabin temperature has been assumed during cabin depressurization transients, to decouple the pressure control section from the air conditioning section). The model allows to check the validity of these kind of assumption. The paper also presents the results obtained with this model for the following experiments: - Normal 24 hour cycle; - Re-entry; - Depressurization due to a micro-meteorite hole; - Failure of the condensate water separators. The first version of ECOSIM will be released to the space industry before the end of year 1992 and the user's feedback will lead to improvements being implemented in later versions. (author)

  14. Warm fusion in Stratego - A case study in the generation of program transformation systems

    NARCIS (Netherlands)

    Johann, P.; Visser, Eelco

    2000-01-01

    Stratego is a domain-specific language for the specification of program transfor- mation systems. The design of Stratego is based on the paradigm of rewriting strategies: user-definable programs in a little language of strategy operators determine where and in what order transformation rules

  15. Greenhouse gas emissions and global warming potential of traditional and diversified tropical rice rotation systems.

    Science.gov (United States)

    Weller, Sebastian; Janz, Baldur; Jörg, Lena; Kraus, David; Racela, Heathcliff S U; Wassmann, Reiner; Butterbach-Bahl, Klaus; Kiese, Ralf

    2016-01-01

    Global rice agriculture will be increasingly challenged by water scarcity, while at the same time changes in demand (e.g. changes in diets or increasing demand for biofuels) will feed back on agricultural practices. These factors are changing traditional cropping patterns from double-rice cropping to the introduction of upland crops in the dry season. For a comprehensive assessment of greenhouse gas (GHG) balances, we measured methane (CH4 )/nitrous oxide (N2 O) emissions and agronomic parameters over 2.5 years in double-rice cropping (R-R) and paddy rice rotations diversified with either maize (R-M) or aerobic rice (R-A) in upland cultivation. Introduction of upland crops in the dry season reduced irrigation water use and CH4 emissions by 66-81% and 95-99%, respectively. Moreover, for practices including upland crops, CH4 emissions in the subsequent wet season with paddy rice were reduced by 54-60%. Although annual N2 O emissions increased two- to threefold in the diversified systems, the strong reduction in CH4 led to a significantly lower (P < 0.05) annual GWP (CH4  + N2 O) as compared to the traditional double-rice cropping system. Measurements of soil organic carbon (SOC) contents before and 3 years after the introduction of upland crop rotations indicated a SOC loss for the R-M system, while for the other systems SOC stocks were unaffected. This trend for R-M systems needs to be followed as it has significant consequences not only for the GWP balance but also with regard to soil fertility. Economic assessment showed a similar gross profit span for R-M and R-R, while gross profits for R-A were reduced as a consequence of lower productivity. Nevertheless, regarding a future increase in water scarcity, it can be expected that mixed lowland-upland systems will expand in SE Asia as water requirements were cut by more than half in both rotation systems with upland crops. © 2015 John Wiley & Sons Ltd.

  16. The Contribution of the Dyadic Parent-Child Interaction Coding System (DPICS) Warm-Up Segments in Assessing Parent-Child Interactions

    Science.gov (United States)

    Shanley, Jenelle R.; Niec, Larissa N.

    2011-01-01

    This study evaluated the inclusion of uncoded segments in the Dyadic Parent-Child Interaction Coding System, an analogue observation of parent-child interactions. The relationships between warm-up and coded segments were assessed, as well as the segments' associations with parent ratings of parent and child behaviors. Sixty-nine non-referred…

  17. Air Force Inspection System: An Application for System-of-Systems (SOS) Engineering

    Science.gov (United States)

    2014-06-19

    JTAC) (Ground), 1 Jan 12 155. JCAS AP MOA 2004-02, Joint Forward Air Controller (Airborne) (FAC(A)), 1 Feb 12 ISO 14001 Environmental Management...1332.35, Transition Assistance for Military Personnel, 9 Dec 1993 115. 104 AFI 90-201 2 August 2013 116. DODD 3020.26, Department of Defense Continuity...sometimes they are called “systems of systems” or “super systems”). Examples of arrays include national communications networks, a mass transit

  18. Thermal comfort and indoor air quality in rooms with integrated personalized ventilation and under-floor air distribution systems

    DEFF Research Database (Denmark)

    Li, Ruixin; Sekhar ., S. C.; Melikov, Arsen Krikor

    2011-01-01

    subjects were collected. The experiments were performed at various combinations of room air and PV air temperatures. The results reveal improved overall thermal sensation and decrease of cold feet complaints, as well as improved inhaled air quality (including perceived air quality) with PV....... The integrated PV-UFAD system, when operated at relatively high temperature of the air supplied from the UFAD system, provided comfortable cooling of the facial region, improved inhaled air quality, and decreased the risk of "cold feet," which is often reported in rooms with UFAD alone. This article explores......-UFAD in comparison with the reference case of UFAD alone or mixing ventilation with a ceiling supply diffuser. Increase of predicted draft rating with the decrease of the local thermal sensation at the feet was identified. The manikin-based equivalent temperature determined for the face was positively correlated...

  19. THE VULNERABILITY OF THE BAIA MARE URBAN SYSTEM (ROMANIA TO EXTREME CLIMATE PHENOMENA DURING THE WARM SEMESTER OF THE YEAR

    Directory of Open Access Journals (Sweden)

    DRAGOTĂ CARMEN

    2013-03-01

    Full Text Available The geographical position of the Baia Mare Urban System (intra-hilly depression favours the occurrence of a wide range of extreme climate phenomena which, coupled with the industrial profile of the city (non-ferrous mining and metallurgical industry triggering typical emissions (CO2, SOX, particulate matters and Pb, might pose a significant threat to human health. The article is aiming to assess the occurrence, frequency and amplitude of these extreme climate phenomena based on monthly and daily extreme climatic values from Baia Mare weather station in order to identify the areas more exposed. A GIS-based qualitative-heuristic method was used, each extreme climatic hazard being evaluated on a 1 to 3 scale according to its significance/impact in the study area and assigned with a weight (w and a rank (r, resulting the climate hazard map for the warm semester of the year. The authors further relate the areas exposed to the selected extreme climatic events to socio-economic aspects: demographic and economic in order to delineate the spatial distribution of the environmental vulnerability in the Baia Mare Urban System.

  20. Modular Air-Coupled Ultrasonic Multichannel System for Inline NDT

    Science.gov (United States)

    Bilcke, M.; Lust, P.; Naert, H.; Blomme, E.; Delrue, S.; Van Den Abeele, K.

    In many production processes it is important to detect in a very early stage basic errors in the fabricatedmaterial. If the errors are not visible from the exterior, ultrasonic inspection is a convenient technique,at least if the nature of the error influences the characteristics of sound passing through the material.Examples are local density variations in non-wovens, delaminations in composites, bad bondings inlaminates, inclusions, cracks or other artefacts in plastic or metal plates, etc. There are two major,difficult requirements imposed by industry to the used detection technique: the sensors shouldn't makephysical contact with the material and the speed of testing must be sufficiently high to enable testingin-line. The former requirement can be met by employing an air-coupled ultrasonic approach, the latterby using a multichannel system.We propose a modular air-coupled ultrasonic multichannel system. Each multichannel module contains12 air-coupled transducers and exists in a transmitter and a receiver version. The desired scan width isobtained by connecting several modules to each other. During the scanning all transducers are spatially fixed while the material is moving forward. This way, speeds up to 1m/s are possible, irrespective ofthe width of the material. To that purpose a FPGA based platform with parallel processing of largenumbers of data streams is implemented in the modules. This allows the implementation of all kind ofprocedures, going from point measurements to more sophisticated techniques. In spite of all measurements being performed in ambient air, the ultrasonic frequency is rather high(1 MHz), but lower frequencies are possible as well. The most obvious set-up of the modules is a through-transmission configuration. However the system can also be used in a pitch-catch configuration which isvery suitable for one-sided testing of thick materials. An examples established in the laboratory is shownto illustrate the performance.

  1. Liquid over-feeding air conditioning system and method

    Science.gov (United States)

    Mei, V.C.; Chen, F.C.

    1993-09-21

    A refrigeration air conditioning system utilizing a liquid over-feeding operation is described. A liquid refrigerant accumulator-heat exchanger is placed in the system to provide a heat exchange relationship between hot liquid refrigerant discharged from condenser and a relatively cool mixture of liquid and vaporous refrigerant discharged from the evaporator. This heat exchange relationship substantially sub-cools the hot liquid refrigerant which undergoes little or no evaporation across the expansion device and provides a liquid over-feeding operation through the evaporator for effectively using 100 percent of evaporator for cooling purposes and for providing the aforementioned mixture of liquid and vaporous refrigerant. 1 figure.

  2. Investigation of air cleaning system response to accident conditions

    International Nuclear Information System (INIS)

    Andrae, R.W.; Bolstad, J.W.; Foster, R.D.; Gregory, W.S.; Horak, H.L.; Idar, E.S.; Martin, R.A.; Ricketts, C.I.; Smith, P.R.; Tang, P.K.

    1980-01-01

    Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported

  3. Integrated Evaluation of Closed Loop Air Revitalization System Components

    Science.gov (United States)

    Murdock, K.

    2010-01-01

    NASA s vision and mission statements include an emphasis on human exploration of space, which requires environmental control and life support technologies. This Contractor Report (CR) describes the development and evaluation of an Air Revitalization System, modeling and simulation of the components, and integrated hardware testing with the goal of better understanding the inherent capabilities and limitations of this closed loop system. Major components integrated and tested included a 4-Bed Modular Sieve, Mechanical Compressor Engineering Development Unit, Temperature Swing Adsorption Compressor, and a Sabatier Engineering and Development Unit. The requisite methodolgy and technical results are contained in this CR.

  4. Limiting Global Warming to Well Below 2 °C: Energy System Modelling and Policy Development

    DEFF Research Database (Denmark)

    This book presents the energy system roadmaps necessary to limit global temperature increase to below 2°C, in order to avoid the catastrophic impacts of climate change. It provides a unique perspective on and critical understanding of the feasibility of a well-below-2°C world by exploring energy...... and at a global scale to offer scientific evidence to underpin complex policy decisions relating to climate change mitigation and interrelated issues like energy security and the energy–water nexus. It includes several chapters directly related to the Nationally Determined Contributions proposed in the context...

  5. Research on Heat Exchange Process in Aircraft Air Conditioning System

    Science.gov (United States)

    Chichindaev, A. V.

    2017-11-01

    Using of heat-exchanger-condenser in the air conditioning system of the airplane Tu-204 (Boeing, Airbus, Superjet 100, MS-21, etc.) for cooling the compressed air by the cold air with negative temperature exiting the turbine results in a number of operational problems. Mainly it’s frosting of the heat exchange surface, which is the cause of live-section channels frosting, resistance increasing and airflow in the system decreasing. The purpose of this work is to analyse the known freeze-up-fighting methods for heat-exchanger-condenser, description of the features of anti-icing protection and offering solutions to this problem. For the problem of optimizing the design of heat exchangers in this work used generalized criterion that describes the ratio of thermal resistances of cold and hot sections, which include: the ratio of the initial values of heat transfer agents flow state; heat exchange surface finning coefficients; factors which describes the ratio of operating parameters and finning area. By controlling the ratio of the thermal resistances can be obtained the desired temperature of the heat exchange surface, which would prevent freezing. The work presents the results of a numerical study of the effect of different combinations of regime and geometrical factors changes on reduction of the heat-exchanger-condenser freezing surface area, including using of variable ratio of thermal resistances.

  6. The effect of improving cow productivity, fertility, and longevity on the global warming potential of dairy systems.

    Science.gov (United States)

    Bell, M J; Wall, E; Russell, G; Simm, G; Stott, A W

    2011-07-01

    This study compared the environmental impact of a range of dairy production systems in terms of their global warming potential (GWP, expressed as carbon dioxide equivalents, CO(2)-eq.) and associated land use, and explored the efficacy of reducing said impact. Models were developed using the unique data generated from a long-term genetic line × feeding system experiment. Holstein-Friesian cows were selected to represent the UK average for milk fat plus protein production (control line) or were selected for increased milk fat plus protein production (select line). In addition, cows received a low forage diet (50% forage) with no grazing or were on a high forage (75% forage) diet with summer grazing. A Markov chain approach was used to describe the herd structure and help estimate the GWP per year and land required per cow for the 4 alternative systems and the herd average using a partial life cycle assessment. The CO(2)-eq. emissions were expressed per kilogram of energy-corrected milk (ECM) and per hectare of land use, as well as land required per kilogram of ECM. The effects of a phenotypic and genetic standard deviation unit improvement on herd feed utilization efficiency, ECM yield, calving interval length, and incidence of involuntary culling were assessed. The low forage (nongrazing) feeding system with select cows produced the lowest CO(2)-eq. emissions of 1.1 kg/kg of ECM and land use of 0.65 m(2)/kg of ECM but the highest CO(2)-eq. emissions of 16.1t/ha of the production systems studied. Within the herd, an improvement of 1 standard deviation in feed utilization efficiency was the only trait of those studied that would significantly reduce the reliance of the farming system on bought-in synthetic fertilizer and concentrate feed, as well as reduce the average CO(2)-eq. emissions and land use of the herd (both by about 6.5%, of which about 4% would be achievable through selective breeding). Within production systems, reductions in CO(2)-eq. emissions per

  7. Tests of a system to exclude roots from buried radioactive waste in a warm, humid climate

    International Nuclear Information System (INIS)

    Murphy, C.E. Jr.; Corey, J.C.; Adriano, D.C.; Decker, O.D.; Griggs, R.D.

    1989-01-01

    Vegetation is commonly used to stabilize the ground covering buried waste sites. However, constituents of buried waste can be brought to the surface if the waste is penetrated by plant roots. An ideal waste burial system would allow the use of vegetation to stabilize the soil above the buried waste but would exclude roots from the waste. One system that shows considerable promise is a slow release encapsulation of a root growth inhibitor (Trifluralin). Projected lifetimes of the capsule are in the order of 100 years. The capsule is bonded to a geotextile, which provides an easy means of distributing the capsule evenly over the area to be protected. Vegetation grown in the soil above the barrier has provided good ground cover, although some decrease in growth has been found in some species. Of the species tested the sensitivity to the biobarrier, as measured by the distance root growth stops near the barrier, is bamboo> bahia grass> bermuda grass> soybean. Potential uses for the biobarrier at the Savannah River Site (SRS) include the protection of clay caps over buried, low-level saltstone and protection of gravel drains and clay caps over decommissioned seepage basins. Trails of the biobarrier as part of waste site caps are scheduled to begin during the next 12 months

  8. The Air Force Air Program and Information Management System (APIMS): A flexible tool for managing your Title V Operating Permits

    Energy Technology Data Exchange (ETDEWEB)

    Weston, A.A.; Gordon, S.R.

    1999-07-01

    The Air Force Command Core System (CCS) is an integrated, activity-based risk management system designed to support the information needs of Environment, Safety, and Occupational Health (ESOH) professionals. These professionals are responsible for managing a complex and often dynamic set of requirements, and therefore, have a need for an information system that can readily be customized to meet their specific needs. This dynamic environment also drives the need for flexibility in the system. The Air Program Information Management System (APIMS) is a module within CCS designed to not only manage permit compliance and emission inventories, but also support the monitoring, recordkeeping, and reporting requirements related to air quality issues. This paper will describe the underlying foundation of CCS, the information linkages within the database, and then summarize the functionality available within the APIMS module to support the Air Quality Managers' information needs, placing emphasis on the flexibility the system provides to manage Title V Operating Permits.

  9. Investigation of Various Novel Air-Breathing Propulsion Systems

    Science.gov (United States)

    Wilhite, Jarred M.

    The current research investigates the operation and performance of various air-breathing propulsion systems, which are capable of utilizing different types of fuel. This study first focuses on a modular RDE configuration, which was mainly studied to determine which conditions yield stable, continuous rotating detonation for an ethylene-air mixture. The performance of this RDE was analyzed by studying various parameters such as mass flow rate, equivalence ratios, wave speed and cell size. For relatively low mass flow rates near stoichiometric conditions, a rotating detonation wave is observed for an ethylene-RDE, but at speeds less than an ideal detonation wave. The current research also involves investigating the newly designed, Twin Oxidizer Injection Capable (TOXIC) RDE. Mixtures of hydrogen and air were utilized for this configuration, resulting in sustained rotating detonation for various mass flow rates and equivalence ratios. A thrust stand was also developed to observe and further measure the performance of the TOXIC RDE. Further analysis was conducted to accurately model and simulate the response of thrust stand during operation of the RDE. Also included in this research are findings and analysis of a propulsion system capable of operating on the Inverse Brayton Cycle. The feasibility of this novel concept was validated in a previous study to be sufficient for small-scale propulsion systems, namely UAV applications. This type of propulsion system consists of a reorganization of traditional gas turbine engine components, which incorporates expansion before compression. This cycle also requires a heat exchanger to reduce the temperature of the flow entering the compressor downstream. While adding a heat exchanger improves the efficiency of the cycle, it also increases the engine weight, resulting in less endurance for the aircraft. Therefore, this study focuses on the selection and development of a new heat exchanger design that is lightweight, and is capable

  10. Air Pollutants Minimalization of Pollutant Absorber with Condensation System

    International Nuclear Information System (INIS)

    Ruhiat, Yayat; Wibowo, Firmanul Catur; Oktarisa, Yuvita

    2017-01-01

    Industrial development has implications for pollution, one of it is air pollution. The amount of air pollutants emitted from industrial depend on several factors which are capacity of its fuel, high chimneys and atmospheric stability. To minimize pollutants emitted from industries is created a tool called Pollutant Absorber (PA) with a condensing system. Research and Development with the approach of Design for Production was used as methodology in making PA. To test the function of PA, the simulation had been done by using the data on industrial emissions Cilegon industrial area. The simulation results in 15 years period showed that the PA was able to minimize the pollutant emissions of SO2 by 38% NOx by 37% and dust by 64%. Differences in the absorption of pollutants shows the weakness of particle separation process in the separator. This condition happen because the condensation process is less optimal during the absorption and separation in the separator. (paper)

  11. Air quality information system (AQIS) for Gauteng: defining best practice

    CSIR Research Space (South Africa)

    Kganyago, P

    2006-10-01

    Full Text Available The National Environmental Management: Air Quality Act, 2004 (Act No 39 of 2004), need for national framework. The national framework will include the norms and standards for air quality information management. NAQIS (National Air Quality...

  12. Counterintuitive effects of Global Warming-induced wind patterns on primary production in the Northern Humboldt Current System.

    Science.gov (United States)

    Mogollón, Rodrigo; Calil, Paulo H R

    2018-04-14

    It has been hypothesized that global warming will strengthen upwelling-favorable winds in the Northern Humboldt Current System (NHCS) as a consequence of the increase of the land-sea thermal gradient along the Peruvian coast. The effect of strengthened winds in this region is assessed with the use of a coupled physical-biogeochemical model forced with projected and climatological winds. Strengthened winds induce an increase in primary production of 2% per latitudinal degree from 9.5°S to 5°S. In some important coastal upwelling sites primary production is reduced. This is due to a complex balance between nutrient availability, nutrient use efficiency, as well as eddy and wind-driven factors. Mesoscale activity induces a net offshore transport of inorganic nutrients, thus reducing primary production in the coastal upwelling region. Wind mixing, in general disadvantageous for primary producers, leads to shorter residence times in the southern and central coastal zones. Overall, instead of a proportional enhancement in primary production due to increased winds, the NHCS becomes only 5% more productive (+ 5 mol C m -2 yr -1 ), 10% less limited by nutrients and 15% less efficient due to eddy-driven effects. It is found that regions with a initial strong nutrient limitation are more efficient in terms of nutrient assimilation which makes them more resilient in face of the acceleration of the upwelling circulation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Hybrid membrane--PSA system for separating oxygen from air

    Science.gov (United States)

    Staiger, Chad L [Albuquerque, NM; Vaughn, Mark R [Albuquerque, NM; Miller, A Keith [Albuquerque, NM; Cornelius, Christopher J [Blackburg, VA

    2011-01-25

    A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

  14. Energy performance of supermarket refrigeration and air conditioning integrated systems

    International Nuclear Information System (INIS)

    Cecchinato, Luca; Corradi, Marco; Minetto, Silvia

    2010-01-01

    The electricity consumption for air conditioning and refrigerated cases in large supermarkets represents a substantial share of the total electricity consumption. The energy efficiency of supermarkets can be improved by optimising components design, recovering thermal and refrigerating energy, adopting innovative technology solutions, integrating the HVAC system with medium temperature and low-temperature refrigeration plants and, finally, reducing thermal loads on refrigerated cases. This study is aimed at investigating the performance of different lay-out and technological solutions and at finding the potential for improving energy efficiency over the traditional systems in different climates. In the analysis chillers and heat pumps working with R410A, medium temperature systems working with R404A and low-temperature systems working both with R404A and R744 were considered. The investigated solutions enable an annual energy saving higher than 15% with respect to the baseline solution for the considered climates.

  15. 75 FR 15620 - Federal Motor Vehicle Safety Standards; Air Brake Systems

    Science.gov (United States)

    2010-03-30

    ... [Docket No. NHTSA 2009-0175] RIN 2127-AK62 Federal Motor Vehicle Safety Standards; Air Brake Systems... Federal motor vehicle safety standard for air brake systems by requiring substantial improvements in... Federal Motor Vehicle Safety Standard (FMVSS) No. 121, Air Brake Systems, to require improved stopping...

  16. Arctic dimension of global warming

    OpenAIRE

    G. V. Alekseev

    2014-01-01

    A brief assessment of the global warming in the Arctic climate system with the emphasis on sea ice is presented. The Arctic region is coupled to the global climate system by the atmosphere and ocean circulation that providesa major contribution to the Arctic energy budget. On this basis using of special indices it is shown that amplification of warming in the Arctic is associated with the increasing of meridional heat transport from the low latitudes.

  17. Thermodynamic analysis of a liquid air energy storage system

    International Nuclear Information System (INIS)

    Guizzi, Giuseppe Leo; Manno, Michele; Tolomei, Ludovica Maria; Vitali, Ruggero Maria

    2015-01-01

    The rapid increase in the share of electricity generation from renewable energy sources is having a profound impact on the power sector; one of the most relevant effects of this trend is the increased importance of energy storage systems, which can be used to smooth out peaks and troughs of production from renewable energy sources. Besides their role in balancing the electric grid, energy storage systems may provide also several other useful services, such as price arbitrage, stabilizing conventional generation, etc.; therefore, it is not surprising that many research projects are under way in order to explore the potentials of new technologies for electric energy storage. This paper presents a thermodynamic analysis of a cryogenic energy storage system, based on air liquefaction and storage in an insulated vessel. This technology is attractive thanks to its independence from geographical constraints and because it can be scaled up easily to grid-scale ratings, but it is affected by a low round-trip efficiency due to the energy intensive process of air liquefaction. The present work aims to assess the efficiency of such a system and to identify if and how it can achieve an acceptable round-trip efficiency (in the order of 50–60%).

  18. Field-Based Estimates of Global Warming Potential in Bioenergy Systems of Hawaii: Crop Choice and Deficit Irrigation.

    Directory of Open Access Journals (Sweden)

    Meghan N Pawlowski

    Full Text Available Replacing fossil fuel with biofuel is environmentally viable from a climate change perspective only if the net greenhouse gas (GHG footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C stock are critical to the system-level balance. Here, we compared GHG flux, crop yield, root biomass, and soil C stock under two potential tropical, perennial grass biofuel feedstocks: conventional sugarcane and ratoon-harvested, zero-tillage napiergrass. Evaluations were conducted at two irrigation levels, 100% of plantation application and at a 50% deficit. Peaks and troughs of GHG emission followed agronomic events such as ratoon harvest of napiergrass and fertilization. Yet, net GHG flux was dominated by carbon dioxide (CO2, as methane was oxidized and nitrous oxide (N2O emission was very low even following fertilization. High N2O fluxes that frequently negate other greenhouse gas benefits that come from replacing fossil fuels with agronomic forms of bioenergy were mitigated by efficient water and fertilizer management, including direct injection of fertilizer into buried irrigation lines. From soil intensively cultivated for a century in sugarcane, soil C stock and root biomass increased rapidly following cultivation in grasses selected for robust root systems and drought tolerance. The net soil C increase over the two-year crop cycle was three-fold greater than the annualized soil surface CO2 flux. Deficit irrigation reduced yield, but increased soil C accumulation as proportionately more photosynthetic resources were allocated belowground. In the first two years of cultivation napiergrass did not increase net greenhouse warming potential (GWP compared to sugarcane, and has the advantage of multiple ratoon harvests per year and less negative effects of deficit irrigation to yield.

  19. Field-Based Estimates of Global Warming Potential in Bioenergy Systems of Hawaii: Crop Choice and Deficit Irrigation.

    Science.gov (United States)

    Pawlowski, Meghan N; Crow, Susan E; Meki, Manyowa N; Kiniry, James R; Taylor, Andrew D; Ogoshi, Richard; Youkhana, Adel; Nakahata, Mae

    2017-01-01

    Replacing fossil fuel with biofuel is environmentally viable from a climate change perspective only if the net greenhouse gas (GHG) footprint of the system is reduced. The effects of replacing annual arable crops with perennial bioenergy feedstocks on net GHG production and soil carbon (C) stock are critical to the system-level balance. Here, we compared GHG flux, crop yield, root biomass, and soil C stock under two potential tropical, perennial grass biofuel feedstocks: conventional sugarcane and ratoon-harvested, zero-tillage napiergrass. Evaluations were conducted at two irrigation levels, 100% of plantation application and at a 50% deficit. Peaks and troughs of GHG emission followed agronomic events such as ratoon harvest of napiergrass and fertilization. Yet, net GHG flux was dominated by carbon dioxide (CO2), as methane was oxidized and nitrous oxide (N2O) emission was very low even following fertilization. High N2O fluxes that frequently negate other greenhouse gas benefits that come from replacing fossil fuels with agronomic forms of bioenergy were mitigated by efficient water and fertilizer management, including direct injection of fertilizer into buried irrigation lines. From soil intensively cultivated for a century in sugarcane, soil C stock and root biomass increased rapidly following cultivation in grasses selected for robust root systems and drought tolerance. The net soil C increase over the two-year crop cycle was three-fold greater than the annualized soil surface CO2 flux. Deficit irrigation reduced yield, but increased soil C accumulation as proportionately more photosynthetic resources were allocated belowground. In the first two years of cultivation napiergrass did not increase net greenhouse warming potential (GWP) compared to sugarcane, and has the advantage of multiple ratoon harvests per year and less negative effects of deficit irrigation to yield.

  20. Experimental analysis of an air-to-air heat recovery unit for balanced ventilation systems in residential buildings

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Seara, Jose; Diz, Ruben; Uhia, Francisco J.; Dopazo, Alberto; Ferro, Jose M. [Area de Maquinas y Motores Termicos, E.T.S. de Ingenieros Industriales, University of Vigo, Campus Lagoas-Marcosende No. 9, 36310 Vigo (Spain)

    2011-01-15

    This paper deals with the experimental analysis of an air-to-air heat recovery unit equipped with a sensible polymer plate heat exchanger (PHE) for balanced ventilation systems in residential buildings. The PHE is arranged in parallel triangular ducts. An experimental facility was designed to reproduce the typical outdoor and exhaust air conditions with regard to temperature and humidity. The unit was tested under balanced operation conditions, as commonly used in practice. A set of tests was conducted under the reference operating conditions to evaluate the PHE performance. Afterwards, an experimental parametric analysis was conducted to investigate the influence of changing the operating conditions on the PHE performance. Experiments were carried out varying the inlet fresh air temperature, the exhaust air relative humidity and the air flow rate. The experimental results are shown and discussed in this paper. (author)

  1. Factors controlling air quality in different European subway systems.

    Science.gov (United States)

    Martins, Vânia; Moreno, Teresa; Mendes, Luís; Eleftheriadis, Konstantinos; Diapouli, Evangelia; Alves, Célia A; Duarte, Márcio; de Miguel, Eladio; Capdevila, Marta; Querol, Xavier; Minguillón, María Cruz

    2016-04-01

    Sampling campaigns using the same equipment and methodology were conducted to assess and compare the air quality at three South European subway systems (Barcelona, Athens and Oporto), focusing on concentrations and chemical composition of PM2.5 on subway platforms, as well as PM2.5 concentrations inside trains. Experimental results showed that the mean PM2.5 concentrations widely varied among the European subway systems, and even among different platforms within the same underground system, which might be associated to distinct station and tunnel designs and ventilation systems. In all cases PM2.5 concentrations on the platforms were higher than those in the urban ambient air, evidencing that there is generation of PM2.5 associated with the subway systems operation. Subway PM2.5 consisted of elemental iron, total carbon, crustal matter, secondary inorganic compounds, insoluble sulphate, halite and trace elements. Of all metals, Fe was the most abundant, accounting for 29-43% of the total PM2.5 mass (41-61% if Fe2O3 is considered), indicating the existence of an Fe source in the subway system, which could have its origin in mechanical friction and wear processes between rails, wheels and brakes. The trace elements with the highest enrichment in the subway PM2.5 were Ba, Cu, Mn, Zn, Cr, Sb, Sr, Ni, Sn, Co, Zr and Mo. Similar PM2.5 diurnal trends were observed on platforms from different subway systems, with higher concentrations during subway operating hours than during the transport service interruption, and lower levels on weekends than on weekdays. PM2.5 concentrations depended largely on the operation and frequency of the trains and the ventilation system, and were lower inside the trains, when air conditioning system was operating properly, than on the platforms. However, the PM2.5 concentrations increased considerably when the train windows were open. The PM2.5 levels inside the trains decreased with the trains passage in aboveground sections. Copyright © 2015

  2. Forest fire forecasting tool for air quality modelling systems

    Energy Technology Data Exchange (ETDEWEB)

    San Jose, R.; Perez, J.L.; Perez, L.; Gonzalez, R.M.; Pecci, J.; Palacios, M.

    2015-07-01

    Adverse effects of smoke on air quality are of great concern; however, even today the estimates of atmospheric fire emissions are a key issue. It is necessary to implement systems for predicting smoke into an air quality modelling system, and in this work a first attempt towards creating a system of this type is presented. Wildland fire spread and behavior are complex Phenomena due to both the number of involved physic-chemical factors, and the nonlinear relationship between variables. WRF-Fire was employed to simulate spread and behavior of some real fires occurred in South-East of Spain and North of Portugal. The use of fire behavior models requires the availability of high resolution environmental and fuel data. A new custom fuel moisture content model has been developed. The new module allows each time step to calculate the fuel moisture content of the dead fuels and live fuels. The results confirm that the use of accurate meteorological data and a custom fuel moisture content model is crucial to obtain precise simulations of fire behavior. To simulate air pollution over Europe, we use the regional meteorological-chemistry transport model WRF-Chem. In this contribution, we show the impact of using two different fire emissions inventories (FINN and IS4FIRES) and how the coupled WRF-FireChem model improves the results of the forest fire emissions and smoke concentrations. The impact of the forest fire emissions on concentrations is evident, and it is quite clear from these simulations that the choice of emission inventory is very important. We conclude that using the WRF-fire behavior model produces better results than using forest fire emission inventories although the requested computational power is much higher. (Author)

  3. Forest fire forecasting tool for air quality modelling systems

    International Nuclear Information System (INIS)

    San Jose, R.; Perez, J.L.; Perez, L.; Gonzalez, R.M.; Pecci, J.; Palacios, M.

    2015-01-01

    Adverse effects of smoke on air quality are of great concern; however, even today the estimates of atmospheric fire emissions are a key issue. It is necessary to implement systems for predicting smoke into an air quality modelling system, and in this work a first attempt towards creating a system of this type is presented. Wildland fire spread and behavior are complex Phenomena due to both the number of involved physic-chemical factors, and the nonlinear relationship between variables. WRF-Fire was employed to simulate spread and behavior of some real fires occurred in South-East of Spain and North of Portugal. The use of fire behavior models requires the availability of high resolution environmental and fuel data. A new custom fuel moisture content model has been developed. The new module allows each time step to calculate the fuel moisture content of the dead fuels and live fuels. The results confirm that the use of accurate meteorological data and a custom fuel moisture content model is crucial to obtain precise simulations of fire behavior. To simulate air pollution over Europe, we use the regional meteorological-chemistry transport model WRF-Chem. In this contribution, we show the impact of using two different fire emissions inventories (FINN and IS4FIRES) and how the coupled WRF-FireChem model improves the results of the forest fire emissions and smoke concentrations. The impact of the forest fire emissions on concentrations is evident, and it is quite clear from these simulations that the choice of emission inventory is very important. We conclude that using the WRF-fire behavior model produces better results than using forest fire emission inventories although the requested computational power is much higher. (Author)

  4. Forest fire forecasting tool for air quality modelling systems

    International Nuclear Information System (INIS)

    San Jose, R.; Perez, J. L.; Perez, L.; Gonzalez, R. M.; Pecci, J.; Palacios, M.

    2015-01-01

    Adverse effects of smoke on air quality are of great concern; however, even today the estimates of atmospheric fire emissions are a key issue. It is necessary to implement systems for predicting smoke into an air quality modelling system, and in this work a first attempt towards creating a system of this type is presented. Wild land fire spread and behavior are complex phenomena due to both the number of involved physic-chemical factors, and the nonlinear relationship between variables. WRF-Fire was employed to simulate spread and behavior of some real fires occurred in South-East of Spain and North of Portugal. The use of fire behavior models requires the availability of high resolution environmental and fuel data. A new custom fuel moisture content model has been developed. The new module allows each time step to calculate the fuel moisture content of the dead fuels and live fuels. The results confirm that the use of accurate meteorological data and a custom fuel moisture content model is crucial to obtain precise simulations of fire behavior. To simulate air pollution over Europe, we use the regional meteorological-chemistry transport model WRF-Chem. In this contribution, we show the impact of using two different fire emissions inventories (FINN and IS4FIRES) and how the coupled WRF-Fire- Chem model improves the results of the forest fire emissions and smoke concentrations. The impact of the forest fire emissions on concentrations is evident, and it is quite clear from these simulations that the choice of emission inventory is very important. We conclude that using the WRF-fire behavior model produces better results than using forest fire emission inventories although the requested computational power is much higher. (Author)

  5. Forest fire forecasting tool for air quality modelling systems

    Energy Technology Data Exchange (ETDEWEB)

    San Jose, R.; Perez, J. L.; Perez, L.; Gonzalez, R. M.; Pecci, J.; Palacios, M.

    2015-07-01

    Adverse effects of smoke on air quality are of great concern; however, even today the estimates of atmospheric fire emissions are a key issue. It is necessary to implement systems for predicting smoke into an air quality modelling system, and in this work a first attempt towards creating a system of this type is presented. Wild land fire spread and behavior are complex phenomena due to both the number of involved physic-chemical factors, and the nonlinear relationship between variables. WRF-Fire was employed to simulate spread and behavior of some real fires occurred in South-East of Spain and North of Portugal. The use of fire behavior models requires the availability of high resolution environmental and fuel data. A new custom fuel moisture content model has been developed. The new module allows each time step to calculate the fuel moisture content of the dead fuels and live fuels. The results confirm that the use of accurate meteorological data and a custom fuel moisture content model is crucial to obtain precise simulations of fire behavior. To simulate air pollution over Europe, we use the regional meteorological-chemistry transport model WRF-Chem. In this contribution, we show the impact of using two different fire emissions inventories (FINN and IS4FIRES) and how the coupled WRF-Fire- Chem model improves the results of the forest fire emissions and smoke concentrations. The impact of the forest fire emissions on concentrations is evident, and it is quite clear from these simulations that the choice of emission inventory is very important. We conclude that using the WRF-fire behavior model produces better results than using forest fire emission inventories although the requested computational power is much higher. (Author)

  6. Performance characteristics of low global warming potential R134a alternative refrigerants in ejector-expansion refrigeration system

    Directory of Open Access Journals (Sweden)

    Mishra Shubham

    2016-12-01

    Full Text Available Performance assessment of ejector-expansion vapor compression refrigeration system with eco-friendly R134a alternative refrigerants (R152a, R1234yf, R600a, R600, R290, R161, R32, and propylene is presented for air-conditioning application. Ejector has been modeled by considering experimental data based correlations of component efficiencies to take care of all irreversibilities. Ejector area ratio has been optimized based on maximum coefficient of performance (COP for typical air-conditioner operating temperatures. Selected refrigerants have been compared based on area ratio, pressure lift ratio, entrainment ratio, COP, COP improvement and volumetric cooling capacity. Effects of normal boiling point and critical point on the performances have been studied as well. Using ejector as an expansion device, maximum improvement in COP is noted in R1234yf (10.1%, which reduces the COP deviation with R134a (4.5% less in basic cycle and 2.5% less in ejector cycle. Hence, R1234yf seems to be best alternative for ejector expansion system due to its mild flammability and comparable volumetric capacity and cooling COP. refrigerant R161 is superior to R134a in terms of both COP and volumetric cooling capacity, although may be restricted for low capacity application due to its flammability.

  7. Air

    CERN Document Server

    Rivera, Andrea

    2017-01-01

    Air is all around us. Learn how it is used in art, technology, and engineering. Five easy-to-read chapters explain the science behind air, as well as its real-world applications. Vibrant, full-color photos, bolded glossary words, and a key stats section let readers zoom in even deeper. Aligned to Common Core Standards and correlated to state standards. Abdo Zoom is a division of ABDO.

  8. A comprehensive data acquisition and management system for an ecosystem-scale peatland warming and elevated CO2 experiment

    Science.gov (United States)

    Krassovski, M. B.; Riggs, J. S.; Hook, L. A.; Nettles, W. R.; Hanson, P. J.; Boden, T. A.

    2015-11-01

    Ecosystem-scale manipulation experiments represent large science investments that require well-designed data acquisition and management systems to provide reliable, accurate information to project participants and third party users. The SPRUCE project (Spruce and Peatland Responses Under Climatic and Environmental Change, http://mnspruce.ornl.gov) is such an experiment funded by the Department of Energy's (DOE), Office of Science, Terrestrial Ecosystem Science (TES) Program. The SPRUCE experimental mission is to assess ecosystem-level biological responses of vulnerable, high carbon terrestrial ecosystems to a range of climate warming manipulations and an elevated CO2 atmosphere. SPRUCE provides a platform for testing mechanisms controlling the vulnerability of organisms, biogeochemical processes, and ecosystems to climatic change (e.g., thresholds for organism decline or mortality, limitations to regeneration, biogeochemical limitations to productivity, and the cycling and release of CO2 and CH4 to the atmosphere). The SPRUCE experiment will generate a wide range of continuous and discrete measurements. To successfully manage SPRUCE data collection, achieve SPRUCE science objectives, and support broader climate change research, the research staff has designed a flexible data system using proven network technologies and software components. The primary SPRUCE data system components are the following: 1. data acquisition and control system - set of hardware and software to retrieve biological and engineering data from sensors, collect sensor status information, and distribute feedback to control components; 2. data collection system - set of hardware and software to deliver data to a central depository for storage and further processing; 3. data management plan - set of plans, policies, and practices to control consistency, protect data integrity, and deliver data. This publication presents our approach to meeting the challenges of designing and constructing an

  9. Human-model hybrid Korean air quality forecasting system.

    Science.gov (United States)

    Chang, Lim-Seok; Cho, Ara; Park, Hyunju; Nam, Kipyo; Kim, Deokrae; Hong, Ji-Hyoung; Song, Chang-Keun

    2016-09-01

    The Korean national air quality forecasting system, consisting of the Weather Research and Forecasting, the Sparse Matrix Operator Kernel Emissions, and the Community Modeling and Analysis (CMAQ), commenced from August 31, 2013 with target pollutants of particulate matters (PM) and ozone. Factors contributing to PM forecasting accuracy include CMAQ inputs of meteorological field and emissions, forecasters' capacity, and inherent CMAQ limit. Four numerical experiments were conducted including two global meteorological inputs from the Global Forecast System (GFS) and the Unified Model (UM), two emissions from the Model Intercomparison Study Asia (MICS-Asia) and the Intercontinental Chemical Transport Experiment (INTEX-B) for the Northeast Asia with Clear Air Policy Support System (CAPSS) for South Korea, and data assimilation of the Monitoring Atmospheric Composition and Climate (MACC). Significant PM underpredictions by using both emissions were found for PM mass and major components (sulfate and organic carbon). CMAQ predicts PM2.5 much better than PM10 (NMB of PM2.5: -20~-25%, PM10: -43~-47%). Forecasters' error usually occurred at the next day of high PM event. Once CMAQ fails to predict high PM event the day before, forecasters are likely to dismiss the model predictions on the next day which turns out to be true. The best combination of CMAQ inputs is the set of UM global meteorological field, MICS-Asia and CAPSS 2010 emissions with the NMB of -12.3%, the RMSE of 16.6μ/m(3) and the R(2) of 0.68. By using MACC data as an initial and boundary condition, the performance skill of CMAQ would be improved, especially in the case of undefined coarse emission. A variety of methods such as ensemble and data assimilation are considered to improve further the accuracy of air quality forecasting, especially for high PM events to be comparable to for all cases. The growing utilization of the air quality forecast induced the public strongly to demand that the accuracy of the

  10. Thermo economical evaluation of retrofitting strategies in air conditioning systems

    Energy Technology Data Exchange (ETDEWEB)

    Tribess, Arlindo; Fiorelli, Flavio Augusto Sanzogo; Hernandez Neto, Alberto [Sao Paulo Univ., SP (Brazil). Escola Politecnica. Dept. de Engenharia Mecanica]. E-mail: atribess@usp.br; fiorelli@usp.br; ahneto@usp.br

    2000-07-01

    In a building project, several subsystems are designed, among them the air conditioning system. Electrical energy consumption profiles show that this subsystem is responsible for 40 to 50% of total consumption in a commercial building. Besides the study of technical aspects that should be considered in order to assure the thermal comfort of the occupants as well the temperature and humidity conditions for an efficient equipment operation, an economical evaluation of this subsystem should be also made. In retrofit projects, the economical aspect is also critical for such projects in order to assure bigger efficiency in an economically attractive way. This paper analyses some strategies that might be adopted in retrofitting an air conditioning system installed in a commercial building with mixed occupation. By mixed we mean that some floors have a typical office occupation profile and other floors are mainly occupied by electronic equipment. This analysis includes both technical and economical evaluation. The proposed solutions performance are compared to the old system, which allows to verify the retrofitting impact in energy consumption reduction and its economical feasibility. (author)

  11. Consistent approach to air-cleaning system duct design

    International Nuclear Information System (INIS)

    Miller, W.H.; Ornberg, S.C.; Rooney, K.L.

    1981-01-01

    Nuclear power plant air-cleaning system effectiveness is dependent on the capability of a duct system to safely convey contaminated gas to a filtration unit and subsequently to a point of discharge. This paper presents a logical and consistent design approach for selecting sheet metal ductwork construction to meet applicable criteria. The differences in design engineers' duct construction specifications are acknowledged. Typical duct construction details and suggestions for their effective use are presented. Improvements in duct design sections of ANSI/ASME N509-80 are highlighted. A detailed leakage analysis of a control room HVAC system is undertaken to illustrate the effects of conceptual design variations on duct construction requirements. Shortcomings of previously published analyses and interpretations of a current standard are included

  12. Application of AirCell Cellular AMPS Network and Iridium Satellite System Dual Mode Service to Air Traffic Management

    Science.gov (United States)

    Shamma, Mohammed A.

    2004-01-01

    The AirCell/Iridium dual mode service is evaluated for potential applications to Air Traffic Management (ATM) communication needs. The AirCell system which is largely based on the Advanced Mobile Phone System (AMPS) technology, and the Iridium FDMA/TDMA system largely based on the Global System for Mobile Communications(GSM) technology, can both provide communication relief for existing or future aeronautical communication links. Both have a potential to serve as experimental platforms for future technologies via a cost effective approach. The two systems are well established in the entire CONUS and globally hence making it feasible to utilize in all regions, for all altitudes, and all classes of aircraft. Both systems have been certified for air usage. The paper summarizes the specifications of the AirCell/Iridium system, as well as the ATM current and future links, and application specifications. the paper highlights the scenarios, applications, and conditions under which the AirCell/Iridium technology can be suited for ATM Communication.

  13. Technology Solutions Case Study: Ventilation System Effectiveness and Tested Indoor Air Quality Impacts

    Energy Technology Data Exchange (ETDEWEB)

    A. Rudd and D. Bergey

    2015-08-01

    Ventilation system effectiveness testing was conducted at two unoccupied, single-family, detached lab homes at the University of Texas - Tyler. Five ventilation system tests were conducted with various whole-building ventilation systems. Multizone fan pressurization testing characterized building and zone enclosure leakage. PFT testing showed multizone air change rates and interzonal airflow filtration. Indoor air recirculation by a central air distribution system can help improve the exhaust ventilation system by way of air mixing and filtration. In contrast, the supply and balanced ventilation systems showed that there is a significant benefit to drawing outside air from a known outside location, and filtering and distributing that air. Compared to the Exhaust systems, the CFIS and ERV systems showed better ventilation air distribution and lower concentrations of particulates, formaldehyde and other VOCs.

  14. Based on Artificial Neural Network to Realize K-Parameter Analysis of Vehicle Air Spring System

    Science.gov (United States)

    Hung, San-Shan; Hsu, Chia-Ning; Hwang, Chang-Chou; Chen, Wen-Jan

    2017-10-01

    In recent years, because of the air-spring control technique is more mature, that air- spring suspension systems already can be used to replace the classical vehicle suspension system. Depend on internal pressure variation of the air-spring, thestiffnessand the damping factor can be adjusted. Because of air-spring has highly nonlinear characteristic, therefore it isn’t easy to construct the classical controller to control the air-spring effectively. The paper based on Artificial Neural Network to propose a feasible control strategy. By using offline way for the neural network design and learning to the air-spring in different initial pressures and different loads, offline method through, predict air-spring stiffness parameter to establish a model. Finally, through adjusting air-spring internal pressure to change the K-parameter of the air-spring, realize the well dynamic control performance of air-spring suspension.

  15. Operability Test Report for 241-U Compressed Air System and heat pump

    International Nuclear Information System (INIS)

    Rensink, G.E.

    1995-01-01

    The 241-U-701 compressed air system supplies instrument quality compressed air to Tank Farm 241-U. The system was upgraded. The operability test showed that the system operates within its intended design parameters. System performance was monitored, recorded, and used to identify areas of concern. Exceptions to the OTP and additional items for safe system performance were minimal and have been resolved; the air system is ready for Operation's use

  16. The effect of fan speed control system on the inlet air temperature uniformity in a solar dryer

    Directory of Open Access Journals (Sweden)

    S. F Mousavi

    2015-09-01

    hours, startingat 8:00 am and terminating at 17:00. To determine the moisture content for the purpose of observing and recording the drying process, the drying materials were sampled with one hour time step. The moisture contentwas determinedin the laboratory using the well- known method of oven drying which is presented elsewhere. Results and discussion: Since the ambient air temperature during the four days of experimental runs was almost the same, the effect of ambient air temperature on the drying process was ignored. Considering the dryer inlet air temperature charts obtained in this study (Fig. 2 and Fig. 3, it can be concluded that for those tests using the fan speed control system, the outlet air temperature of the collector during drying period associated with very little variations, is compared with the no control mode runs. At the beginning of the day and also during the hours at the end of the day, due to a decrease in the temperature of the absorber plate compared to the middle of theday, the fan speed is reduced as air passes slowly through the absorber plate and hence the temperature rises. But in the middle of the day, with increasing the temperature of absorber plate, the speed of the fan is increased to provide sufficient airflow and to prevent the absorber plate from warming up. Inexperiments without fan speed control, the fan works with no limitation, and the temperature of the inlet air was changed with the temperature change in the absorber plate. The fan speed control system in addition to lowering the temperature changes in the outlet air, also increased the average outlet temperature about 3C, compared to the dryer without such a control system. During the twodays of experiments, the average ambient air temperature was 28C and at the sametime the outlet air temperature was 40.6 and 40.8C, respectively. In twodays of no control system, the average temperature of the ambient air was 28.5 and 28C and at the sametime the outlet air

  17. Performance Study of Salt Cavern Air Storage Based Non-Supplementary Fired Compressed Air Energy Storage System

    Science.gov (United States)

    Chen, Xiaotao; Song, Jie; Liang, Lixiao; Si, Yang; Wang, Le; Xue, Xiaodai

    2017-10-01

    Large-scale energy storage system (ESS) plays an important role in the planning and operation of smart grid and energy internet. Compressed air energy storage (CAES) is one of promising large-scale energy storage techniques. However, the high cost of the storage of compressed air and the low capacity remain to be solved. This paper proposes a novel non-supplementary fired compressed air energy storage system (NSF-CAES) based on salt cavern air storage to address the issues of air storage and the efficiency of CAES. Operating mechanisms of the proposed NSF-CAES are analysed based on thermodynamics principle. Key factors which has impact on the system storage efficiency are thoroughly explored. The energy storage efficiency of the proposed NSF-CAES system can be improved by reducing the maximum working pressure of the salt cavern and improving inlet air pressure of the turbine. Simulation results show that the electric-to-electric conversion efficiency of the proposed NSF-CAES can reach 63.29% with a maximum salt cavern working pressure of 9.5 MPa and 9 MPa inlet air pressure of the turbine, which is higher than the current commercial CAES plants.

  18. Selection of option of pregame warm-up in handball taking into account features of force of the nervous system of sportsmen

    Directory of Open Access Journals (Sweden)

    Helen Gant

    2016-06-01

    Full Text Available Purpose: to develop recommendations about the organization of warm-up for handball players of 13–14 years old taking into account force of the nervous system (NS of players. Material & Methods: 28 handball players of 13–14 years old of Kharkov and Ternovka took part in the research; methods were used: analysis of scientific and methodical literature, technique of "Tapping-test". Results: need of the search of new ways of the increase of efficiency of the competitive activity of young handball players is proved theoretically. Psychological characteristics of handball players of 13–14 years old with a different force of the nervous system are provided. Practical recommendations about the organization of pregame warm-up of handball players of 13–14 years old taking into account force of nervous system of sportsmen are developed. Conclusions: handball players of 13–14 years old can be divided into five groups, concerning force of their nervous system by the results of the conducted research: strong NS (28,57%, average (21,43%, weak (17,86% and average and weak (14,29%, average and strong (17,86%. Recommendations about the organization and carrying out pregame warm-up of handball players of 13–14 years old, taking into account force of the nervous system of sportsmen were developed, considering the results of the psychological research of sportsmen.

  19. The effect of a personalized ventilation system on perceived air quality and SBS symptoms

    DEFF Research Database (Denmark)

    Kaczmarczyk, Jan; Zeng, Q.; Melikov, Arsen Krikor

    2002-01-01

    Perceived air quality, SBS symptoms and performance were studied with 30 human subjects. Experiments were performed in an office set-up with six workplaces, each equipped with a Personalized Ventilation System (PVS). Each PVS allowed the amount of supply air and its direction to be controlled...... condition in regard to perceived air quality, perception of freshness and intensity of SBS symptoms was when PVS supplied outdoor air at 20 deg.C. Perceived air quality in this case was significantly better (p...

  20. Indoor Air Quality and Thermal Conditions in a Primary School with a Green Roof System

    Directory of Open Access Journals (Sweden)

    Nikolaos Barmparesos

    2018-02-01

    Full Text Available This paper presents experimental results from a typical school building in Athens, equipped partly with a green roof system (GRS. Environmental monitoring took place in six classrooms located both under the concrete roof and the GRS sectors as well as in the immediate external environment during the warm and cold periods of a school year. Daily measurements of pollutants CO2, TVOCs (Total Volatile Organic Compound, PM1, PM2.5, and PM10 were performed in selected classes. Moreover, indoor ambient temperature (T and relative humidity (RH measurements were implemented in order to estimate the absolute humidity (AH and assess the indoor environmental conditions. The results highlight that during summer, the GRS reduces temperature in a classroom on the top floor by about 2.8 °C, in comparison with the respective classroom under the concrete roof and that AH remained relatively stable for both classrooms. Amid winter, a reverse behavior occurs only for temperature. Moreover, air exchange rates (AER were calculated by using the CO2 decay method for all of the classrooms. The results demonstrated insufficient ventilation for all experimental sights. Finally, concentrations of PM1, PM2.5 and PM10, were found to be relatively decreased, with average values of 0.79, 3.39, and 27.80 μg m−3. Levels of CO2 and TVOCs were elevated during class hours ranging from 469 to 779 ppm and from 6.63 ppm to 13.33 ppm, respectively, but generally within the respective limits of exposure. The examination of the indoor/outdoor (I/O ratio of air pollutants, demonstrated that the outdoor meteorology affects only PM1 and PM2.5, as PM10 and TVOCs are strongly affected by internal sources and the activities of pupils.

  1. Air distribution system with the discharge action in the working cavity of downhole air hammer drills

    Science.gov (United States)

    Timonin, VV; Alekseev, SE; Kokoulin, DI; Kubanychbek, B.

    2018-03-01

    It is proposed to carry out pre-mine methane drainage using underground degassing holes made by downhole air hammer drills. The features of downhole air drills are described. The downhole air drill layout with the simple-shape striking part is presented with its pluses and minuses. The researchers point at available options to eliminate the shortcomings. The improved layout of the downhole air hammer drill is suggested. The paper ends with the test data on the prototype air hammer drill, its characteristics and trial drilling results.

  2. Air

    International Nuclear Information System (INIS)

    Gugele, B.; Scheider, J.; Spangl, W.

    2001-01-01

    In recent years several regulations and standards for air quality and limits for air pollution were issued or are in preparation by the European Union, which have severe influence on the environmental monitoring and legislation in Austria. This chapter of the environmental control report of Austria gives an overview about the legal situation of air pollution control in the European Union and in specific the legal situation in Austria. It gives a comprehensive inventory of air pollution measurements for the whole area of Austria of total suspended particulates, ozone, volatile organic compounds, nitrogen oxides, sulfur dioxide, carbon monoxide, heavy metals, benzene, dioxin, polycyclic aromatic hydrocarbons and eutrophication. For each of these pollutants the measured emission values throughout Austria are given in tables and geographical charts, the environmental impact is discussed, statistical data and time series of the emission sources are given and legal regulations and measures for an effective environmental pollution control are discussed. In particular the impact of fossil-fuel power plants on the air pollution is analyzed. (a.n.)

  3. Proteoglycan and collagen expression during human air conducting system development

    Directory of Open Access Journals (Sweden)

    C. Godoy-Guzmán

    2012-06-01

    Full Text Available The lung is formed from a bud that grows and divides in a dichotomous way. A bud is a new growth center which is determined by epithelial-mesenchymal interactions where proteins of the extracellular matrix (ECM might be involved. To understand this protein participation during human lung development, we examined the expression and distribution of proteoglycans in relation to the different types of collagens during the period in which the air conducting system is installed. Using light microscopy and immunohistochemistry we evaluate the expression of collagens (I, III and VI and proteoglycans (decorin, biglycan and lumican between 8 to 10 weeks post fertilization and 11 to 14 weeks of gestational age of human embryo lungs. We show that decorin, lumican and all the collagen types investigated were expressed at the epithelium-mesenchymal interface, forming a sleeve around the bronchiolar ducts. In addition, biglycan was expressed in both the endothelial cells and the smooth muscle of the blood vessels. Thus, the similar distribution pattern of collagen and proteoglycans in the early developmental stages of the human lung may be closely related to the process of dichotomous division of the bronchial tree. This study provides a new insight concerning the participation of collagens and proteoglycans in the epithelial-mesenchymal interface during the period in which the air conducting system is installed in the human fetal lung.

  4. Heterotrophic bacteria in an air-handling system.

    Science.gov (United States)

    Hugenholtz, P; Fuerst, J A

    1992-12-01

    Heterotrophic bacteria from structural surfaces, drain pan water, and the airstream of a well-maintained air-handling system with no reported building-related illness were enumerated. Visually the system appeared clean, but large populations of bacteria were found on the fin surface of the supply-side cooling coils (10(5) to 10(6) CFU cm-2), in drain pan water (10(5) to 10(7) CFU ml-1), and in the sump water of the evaporative condenser (10(5) CFU ml-1). Representative bacterial colony types recovered from heterotrophic plate count cultures on R2A medium were identified to the genus level. Budding bacteria belonging to the genus Blastobacter dominated the supply surface of the coil fins, the drain pan water, and the postcoil air. These data and independent scanning electron microscopy indicated that a resident population of predominantly Blastobacter bacteria was present as a biofilm on the supply-side cooling coil fins.

  5. 49 CFR 571.121 - Standard No. 121; Air brake systems.

    Science.gov (United States)

    2010-10-01

    ... Motor Vehicle Safety Standards § 571.121 Standard No. 121; Air brake systems. S1. Scope. This standard establishes performance and equipment requirements for braking systems on vehicles equipped with air brake... compressed air or vacuum only to assist the driver in applying muscular force to hydraulic or mechanical...

  6. Modelling an infrared Man Portable Air Defence System

    Science.gov (United States)

    Birchenall, Richard P.; Richardson, Mark A.; Brian, Butters; Roy, Walmsley

    2010-09-01

    The global proliferation of shoulder launched IR Man Portable Air Defence Systems (ManPADS) has resulted in the existence of a serious threat to both civilian and military aircraft from terrorist attack. Some of the older generations of ManPADS can be defeated with modern countermeasures but even the most sophisticated protection still has vulnerabilities to the latest family of ManPADS. This paper describes the work undertaken by the authors to model a second generation ManPAD, based on the Russian SA-14, and assess the vulnerabilities of aircraft both with and without flare countermeasures from these systems. The conclusions are the results of over 11,000 simulated firings against targets of varying aspects, velocities and altitudes.

  7. System to determine the incoming direction of air showers

    International Nuclear Information System (INIS)

    Nagano, Motohiko

    1984-01-01

    The incoming direction of air showers is determined by the measurement of the time difference of events observed at three or more observation points. The errors due to the measurement of time difference come from the thickness of shower plane, the fluctuation of the drift time of electrons in a photomultiplier, the walk effect of a trigger circuit, and the errors due to the recording system. One must take care of these effects of the detection system. The circuits used for the measurement of time difference are of time-stretcher type, vernier counter type, and direct time difference counting type. The accuracy of the determination of incoming direction depends on shower size. The practical standard deviation was about a few degree. (Kato, T.)

  8. Development and testing of an unmanned air vehicle telemetry system

    Science.gov (United States)

    Wilhelm, Kevin T.

    1991-09-01

    Unmanned air vehicles (UAV's) provide a low-cost, low-maintenance, and effective platform upon which experimentation can be performed to validate conceptual aerodynamic ideas. However, the UAV flight test data acquisition process is complex and requires a reliable recording system for post-flight data analysis. The thrust of this thesis was the development, construction, and validation of a viable telemetry system for data gathering and processing. Major areas of focus were: integration of the telemetry into a 1/8 scale model, radio controlled F-16A airplane; telemetry circuitry optimization; recording and display of instrumented parameters; and data reduction techniques necessary to obtain useful information. A flight test was flown and data was gathered using a steady-heading side-slip maneuver to demonstrate successful integration of all supporting elements.

  9. Alterations in mitochondrial electron transport system activity in response to warm acclimation, hypoxia-reoxygenation and copper in rainbow trout, Oncorhynchus mykiss

    International Nuclear Information System (INIS)

    Sappal, Ravinder; MacDougald, Michelle; Fast, Mark; Stevens, Don; Kibenge, Fred; Siah, Ahmed; Kamunde, Collins

    2015-01-01

    Highlights: • Sequential inhibition and activation allows assessment of multiple segments of the electron transport system. • Warm acclimation and hypoxia-reoxygenation have global effects on the electron transport system. • Warm acclimation and hypoxia-reoxygenation sensitize the electron transport system to copper. • Thermal stress, hypoxia-reoxygenation and copper act additively to impair mitochondrial function. - Abstract: Fish expend significant amounts of energy to handle the numerous potentially stressful biotic and abiotic factors that they commonly encounter in aquatic environments. This universal requirement for energy singularizes mitochondria, the primary cellular energy transformers, as fundamental drivers of responses to environmental change. Our study probed the interacting effects of thermal stress, hypoxia-reoxygenation (HRO) and copper (Cu) exposure in rainbow trout to test the prediction that they act jointly to impair mitochondrial function. Rainbow trout were acclimated to 11 (controls) or 20 °C for 2 months. Liver mitochondria were then isolated and their responses in vitro to Cu (0–20 μM) without and with HRO were assessed. Sequential inhibition and activation of mitochondrial electron transport system (ETS) enzyme complexes permitted the measurement of respiratory activities supported by complex I–IV (CI–IV) in one run. The results showed that warm acclimation reduced fish and liver weights but increased mitochondrial protein indicating impairment of energy metabolism, increased synthesis of defense proteins and/or reduced liver water content. Whereas acute rise (11 → 20 °C) in temperature increased mitochondrial oxidation rates supported by CI–IV, warm acclimation reduced the maximal (state 3) and increased the basal (state 4) respiration leading to global uncoupling of oxidative phosphorylation (OXPHOS). HRO profoundly inhibited both maximal and basal respiration rates supported by CI–IV, reduced RCR for all except

  10. Alterations in mitochondrial electron transport system activity in response to warm acclimation, hypoxia-reoxygenation and copper in rainbow trout, Oncorhynchus mykiss

    Energy Technology Data Exchange (ETDEWEB)

    Sappal, Ravinder [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); MacDougald, Michelle [Faculty of Medicine, Memorial University of Newfoundland, Health Sciences Centre, Prince Philip Drive, St. John’s, NL, A1B 3V6 (Canada); Fast, Mark [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Stevens, Don [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Kibenge, Fred [Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada); Siah, Ahmed [British Columbia Centre for Aquatic Health Sciences, 871A Island Highway, Campbell River, BC, V9W 2C2 (Canada); Kamunde, Collins, E-mail: ckamunde@upei.ca [Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3 (Canada)

    2015-08-15

    Highlights: • Sequential inhibition and activation allows assessment of multiple segments of the electron transport system. • Warm acclimation and hypoxia-reoxygenation have global effects on the electron transport system. • Warm acclimation and hypoxia-reoxygenation sensitize the electron transport system to copper. • Thermal stress, hypoxia-reoxygenation and copper act additively to impair mitochondrial function. - Abstract: Fish expend significant amounts of energy to handle the numerous potentially stressful biotic and abiotic factors that they commonly encounter in aquatic environments. This universal requirement for energy singularizes mitochondria, the primary cellular energy transformers, as fundamental drivers of responses to environmental change. Our study probed the interacting effects of thermal stress, hypoxia-reoxygenation (HRO) and copper (Cu) exposure in rainbow trout to test the prediction that they act jointly to impair mitochondrial function. Rainbow trout were acclimated to 11 (controls) or 20 °C for 2 months. Liver mitochondria were then isolated and their responses in vitro to Cu (0–20 μM) without and with HRO were assessed. Sequential inhibition and activation of mitochondrial electron transport system (ETS) enzyme complexes permitted the measurement of respiratory activities supported by complex I–IV (CI–IV) in one run. The results showed that warm acclimation reduced fish and liver weights but increased mitochondrial protein indicating impairment of energy metabolism, increased synthesis of defense proteins and/or reduced liver water content. Whereas acute rise (11 → 20 °C) in temperature increased mitochondrial oxidation rates supported by CI–IV, warm acclimation reduced the maximal (state 3) and increased the basal (state 4) respiration leading to global uncoupling of oxidative phosphorylation (OXPHOS). HRO profoundly inhibited both maximal and basal respiration rates supported by CI–IV, reduced RCR for all except

  11. Air pollution and neuroendocrine stress-mediated systemic metabolic and inflammatory response

    Science.gov (United States)

    New experimental evidence involving the role of neuroendocrine activation challenges an accepted mechanistic paradigm of how irritant air pollutants induce systemic metabolic impairment and lung injury/inflammation. We focus on recent air pollution studies highlighting how the re...

  12. Bio-Electrochemical Carbon Dioxide Removal for Air Revitalization in Exploration Life Support Systems, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — An important aspect of the ISS air revitalization system for life support is the removal of carbon dioxide from cabin air and retrieves oxygen from CO2. The current...

  13. Global warming : a guide to the science

    International Nuclear Information System (INIS)

    Soon, W.; Baliunas, S.L.; Robinson, A.B.; Robinson, Z.W.

    2001-01-01

    This guide dispels the popular hypothesis that increases in carbon dioxide in the atmosphere resulting from increased industrial activity have caused global warming. The report suggests that there is no evidence of catastrophic anthropogenic global warming and that temperature changes over the last 100 years has been due mostly to natural phenomena. The global temperature has increased by about 0.5 to 0.6 degrees C in the past 100 years, and this, before most of the greenhouse gases were added to the air by human activities such as burning of fossil fuels. The initial major rise in temperature was in 1940, before the rise in carbon dioxide levels, therefore, it was suggested that this warming must have been natural in origin. Computer based simulations of the climate system forecast disastrous rises in global temperature. But it was argued that current climate models are not accurate in forecasting future climate change because it is not possible to isolate the effect of an increased concentration of atmospheric carbon dioxide on climate because about 5 million different variables have to be considered with all their important impacts and interactions. Science indicates that at most, a little warming will occur and certainly better plant grown which should be of great benefit to mankind. It was concluded that the human condition can be improved through unconstrained access to energy, but use of energy may also produce local unwanted pollutants as a by product. The sources of true environmental pollution can be mitigated based on rational considerations of the risks of pollutants and benefits of energy use. refs., figs

  14. On warm Rossby waves and their relations to ENSO events

    OpenAIRE

    Takeuchi, K.

    1989-01-01

    The hypothesis suggested by several simple air-sea coupled models is examined with an ocean numerical model driven by FSU wind stress for the period from 1963 to 1987. The examined hypothesis is that warm Rossby waves generated by stronger trades associated with cold events following warm episodes are responsible for triggering the next warm events as results, following are found. 1) Warm Rossby wawes are always found approaching the western boundary of the tropical Pacific in the preceding w...

  15. Matching Calculation and Performance Analysis for Aero Engine Starting Air Feeding System

    Science.gov (United States)

    2016-03-30

    Manual (No 14: Auxiliary Power Unit and Starter ), Aviation Industry Press, Beijing, 2000. 3. Meng, W.S., Zhao N. and Ju Y.G., “ Research and...pipeline-air turbine starter (ATS)” system, which has the advantages of flexibility and high efficiency, is investigated based on APU air bleeding...emphatically studied, and principles should be following when designing starting air feeding system are provided. Keywords: air turbine starter

  16. Impact of the Air-Conditioning System on the Power Consumption of an Electric Vehicle Powered by Lithium-Ion Battery

    Directory of Open Access Journals (Sweden)

    Brahim Mebarki

    2013-01-01

    Full Text Available The car occupies the daily universe of our society; however, noise pollution, global warming gas emissions, and increased fuel consumption are constantly increasing. The electric vehicle is one of the recommended solutions by the raison of its zero emission. Heating and air-conditioning (HVAC system is a part of the power system of the vehicle when the purpose is to provide complete thermal comfort for its occupants, however it requires far more energy than any other car accessory. Electric vehicles have a low-energy storage capacity, and HVAC may consume a substantial amount of the total energy stored, considerably reducing the vehicle range, which is one of the most important parameters for EV acceptability. The basic goal of this paper is to simulate the air-conditioning system impact on the power energy source of an electric vehicle powered by a lithium-ion battery.

  17. Thermoeconomic evaluation of air conditioning system with chilled water storage

    International Nuclear Information System (INIS)

    Lin, Hu; Li, Xin-hong; Cheng, Peng-sheng; Xu, Bu-gong

    2014-01-01

    Highlights: • A new thermoeconomic evaluation methodology has been presented. • The relationship between thermodynamic and economic performances has been revealed. • A key point for thermal storage technology further application is discovered. • A system has been analyzed via the new method and EUD method. - Abstract: As a good load shifting technology for power grid, chilled energy storage has been paid more and more attention, but it always consumes more energy than traditional air conditioning system, and the performance analysis is mostly from the viewpoint of peak-valley power price to get cost saving. The paper presents a thermoeconomic evaluation methodology for the system with chilled energy storage, by which thermodynamic performance influence on cost saving has been revealed. And a system with chilled storage has been analyzed, which can save more than 15% of power cost with no energy consumption increment, and just certain difference between peak and valley power prices can make the technology for good economic application. The results show that difference between peak and valley power prices is not the only factor on economic performance, thermodynamic performance of the storage system is the more important factor, and too big price difference is a barrier for its application, instead of for more cost saving. All of these give a new direction for thermal storage technology application

  18. Energy and air emission implications of a decentralized wastewater system

    International Nuclear Information System (INIS)

    Shehabi, Arman; Stokes, Jennifer R; Horvath, Arpad

    2012-01-01

    Both centralized and decentralized wastewater systems have distinct engineering, financial and societal benefits. This paper presents a framework for analyzing the environmental effects of decentralized wastewater systems and an evaluation of the environmental impacts associated with two currently operating systems in California, one centralized and one decentralized. A comparison of energy use, greenhouse gas emissions and criteria air pollutants from the systems shows that the scale economies of the centralized plant help lower the environmental burden to less than a fifth of that of the decentralized utility for the same volume treated. The energy and emission burdens of the decentralized plant are reduced when accounting for high-yield wastewater reuse if it supplants an energy-intensive water supply like a desalination one. The centralized facility also reduces greenhouse gases by flaring methane generated during the treatment process, while methane is directly emitted from the decentralized system. The results are compelling enough to indicate that the life-cycle environmental impacts of decentralized designs should be carefully evaluated as part of the design process. (letter)

  19. Mobile system for on-road measurements of air pollutants

    Science.gov (United States)

    Katulski, Ryszard J.; Namieśnik, Jacek; Sadowski, Jarosław; Stefański, Jacek; Szymańska, Krystyna; Wardencki, Waldemar

    2010-04-01

    The paper presents a prototype of a mobile monitoring system for measuring the levels of the main traffic air pollutants (C6H6, NO2, NOx, CO, and CO2,) in cities. The novelty of the proposed system lies in the fact that it can be utilized to monitor emissions from urban traffic along roads and areas where traditional monitoring stations cannot be placed. In the proposed system, the monitoring device can be mounted on any moving vehicle (such as a car, bus, or truck) rather than be attached to a dedicated van, as most systems of this kind found in literature are. Analyzers used in this system are small portable structures that contain an electronic instrument to measure, record, and transmit relevant data on concentrations of the pollutants to a website. The model outcome for carbon monoxide obtained in functional tests in real conditions is also presented here. Data on temporal changes of carbon monoxide concentration are compared against meteorological parameters and speed of the vehicle. Spatial interpolation techniques are applied to obtain a nonplanar visualization of carbon monoxide and benzene concentrations in the main arteries of a city.

  20. Methodology for the energy analysis of compressed air systems; Metodologia para analisis energetico de sistemas de aire comprimido

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez, T.; Ambriz, J. J.; Romero, H. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

    1992-12-31

    In this paper a methodology for the diagnosis of compressed air systems, for the identification of the potential energy saving is presented. The methodology consists in detecting the largest number of possible ways of energy saving. For this purpose it is divided into three parts: 1. Compressed air generation. 2. Compressed air distribution. 3. Compressed air users. For each one of the parts, the type of information required to perform the diagnosis study, as well as the necessary measuring equipment needed, is indicated. Afterwards, the possible saving ways that can be found and the ones that can be feasible, are analyzed. [Espanol] En este trabajo se presenta una metodologia para diagnosticar sistemas de aire comprimido, para identificar los potenciales de ahorro de energia. La metodologia consiste en detectar el mayor numero de posibles medidas de ahorro, para lo cual se divide en tres partes: 1. Generacion de aire comprimido. 2. Distribucion del aire comprimido. 3 Usuarios de aire comprimido. Para cada una de las partes se indica el tipo de informacion requerida para realizar el estudio de diagnostico, asi como el uso de equipo necesario de medicion. Despues se analizan las posibles medidas de ahorro que se pueden encontrar y las que pueden ser viables.

  1. The Career Job Reservation System. Is the Issuance System Best Serving the Needs of the Air Force?

    Science.gov (United States)

    1990-04-01

    AD-A241 065 (i AIR WAR COLLEGE RESEARCH REPORT THE CAREER JOB RESERVATION SYSTEM- IS THE ISSUANCE SYSTEM BEST SERVING THE NEEDS OF THE AIR FORCE... THE NEEDS OF THE AIR FORCE? by Ernest V. Marshall Lieutenant Colonel, USAF A DEFENSE ANALYTICAL STUDY SUBMITTED TO THE FACULTY IN FULFILLMENT OF THE...EXECUTIVE SUMMARY TITLE: The Career Job Reservation (CJR) Sy3tem--Is it serving the needs of the Air Force? AUTHOR: Ernest V. Marshall, Licutenant

  2. Air pollution and its impact on the cardiovascular system

    Directory of Open Access Journals (Sweden)

    Marjorie Paris Colombini

    2008-03-01

    Full Text Available Despite the great medical advances, cardiovascular disease remains one of the major causes of mortality worldwide, especially in industrialized countries. It develops as a result of countless complex interactions between genetic factors such as those related to age, sex, family history, weight, and post-menopausal status in women; and to environment-related factors such as cigarette smoking, alcohol use, eating habits, physical activity, and others. For more than a decade, several epidemiological studies have demonstrated the existence of a consistent association between air pollution and increased risk for cardiovascular events, that is, not only cardiovascular death, but also acute myocardial infarction and arrhythmias. Experimental studies in different animal species, observational studies in humans, as well as in vitro cellular and acellular models attempt to elucidate the probable biological mechanisms that lend plausibility to these associations, but they fail to do it clearly, since the severity and progression of cardiovascular disease are much more affected than is its induction. However, some effects resulting from the exposure to different air pollutants have been evidenced and the most significant of which involve pulmonary and systemic inflammatory response, blood clotting disorders, promotion and potentiation of the atherosclerotic process, and cardiac autonomic dysfunction.

  3. 24 CFR 3280.715 - Circulating air systems.

    Science.gov (United States)

    2010-04-01

    ... applied only to surfaces that are dry and dust-, dirt-, oil-, and grease-free. Tapes and mastic closure..., Factory Made Air Ducts and Connectors. Air supply terminal devices (registers) when installed in kitchen...

  4. Active Participation of Air Conditioners in Power System Frequency Control Considering Users’ Thermal Comfort

    Directory of Open Access Journals (Sweden)

    Rongxiang Zhang

    2015-09-01

    Full Text Available Air conditioners have great potential to participate in power system frequency control. This paper proposes a control strategy to facilitate the active participation of air conditioners. For each air conditioner, a decentralized control law is designed to adjust its temperature set point in response to the system frequency deviation. The decentralized control law accounts for the user’s thermal comfort that is evaluated by a fuzzy algorithm. The aggregation of air conditioners’ response is conducted by using the Monte Carlo simulation method. A structure preserving model is applied to the multi-bus power system, in which air conditioners are aggregated at certain load buses. An inner-outer iteration scheme is adopted to solve power system dynamics. An experiment is conducted on a test air conditioner to examine the performance of the proposed decentralized control law. Simulation results on a test power system verify the effectiveness of the proposed strategy for air conditioners participating in frequency control.

  5. Improving Compressed Air System Performance: A Sourcebook for Industry v3

    Energy Technology Data Exchange (ETDEWEB)

    Ron Marshall, William Scales, Gary Shafer, Paul Shaw, Paul Sheaffer, Rick Stasyshan, H.P.

    2016-03-01

    This sourcebook is designed to provide compressed air system users with a reference that outlines opportunities for system performance improvements. It is not intended to be a comprehensive technical text on improving compressed air systems, but rather a document that makes compressed air system users aware of the performance improvement potential, details some of the significant opportunities, and directs users to additional sources of assistance.

  6. ECOLO-HOUSE in the snowy town. Study of the ventilating function what the heat collecting system of the air duct utilizing attic has; Yukiguni ECOLO-HOUSE. Kison kaoku no yaneura wo riyoshita duct shunetsu system

    Energy Technology Data Exchange (ETDEWEB)

    Umemiya, H.; Hirosawa, K. [Yamagata University, Yamagata (Japan)

    1996-10-27

    Described in this paper is an air duct heat collecting system, forming a link in the chain of natural energy utilization, in an attic of a house actually in presence. When a sirocco fan (blowing air from an indoor induction duct into the room) at the base of the highblocked floor is turned, air is sucked through an air intake under the eaves into a heat collecting duct (constructed utilizing the tilt roof and rafter). Heat from the roof warmed by sunshine is absorbed by air in the heat collecting duct and is fed to the highblocked floor structure through a heat collecting room and the induction duct. This system functions quite effectively as a ventilating device. Dew condensation on the walls and floor and musty smell have been eliminated. This system is good enough as a heater even on chilly days in early spring when there is sunshine. In the time zone with the sun shining, the system collects 4{times}10{sup 4}kJ per day, exhibiting a heat collecting efficiency of 4%. The heat collecting duct was analyzed for thermal environment, and the heat flux of the collected heat was determined as Qk(W/m{sup 2}=0.1{times}I-1.3{Theta}d-{Theta}a). In this equation, I is the quantity of insolation (W/m{sup 2}), {Theta}d is the temperature in the heat collecting duct, and {Theta}a is the free air temperature. 2 refs., 8 figs.

  7. Experimental Study of Air Vessel Behavior for Energy Storage or System Protection in Water Hammer Events

    Directory of Open Access Journals (Sweden)

    Mohsen Besharat

    2017-01-01

    Full Text Available An experimental assessment of an air pocket (AP, confined in a compressed air vessel (CAV, has been investigated under several different water hammer (WH events to better define the use of protection devices or compressed air energy storage (CAES systems. This research focuses on the size of an AP within an air vessel and tries to describe how it affects important parameters of the system, i.e., the pressure in the pipe, stored pressure, flow velocity, displaced volume of water and water level in the CAV. Results present a specific range of air pockets based on a dimensionless parameter extractable for other real systems.

  8. 75 FR 18255 - Passenger Facility Charge Database System for Air Carrier Reporting

    Science.gov (United States)

    2010-04-09

    ... Facility Charge Database System for Air Carrier Reporting AGENCY: Federal Aviation Administration (FAA... the Passenger Facility Charge (PFC) database system to report PFC quarterly report information. In... the FAA's PFC database system, those air carriers and public agencies participating in the system will...

  9. Cooling load calculations of radiant and all-air systems for commercial buildings

    DEFF Research Database (Denmark)

    Bourdakis, Eleftherios; Bauman, Fred; Schiavon, Stefano

    The authors simulated in TRNSYS three radiant systems coupled with a 50% sized variable air volume (VAV) system and a 50% sized all-air VAV system with night ventilation. The objective of this study was to identify the differences in the cooling load profiles of the examined systems when they are...

  10. Development of a water-mist cooling system: A 12,500 Kcal/h air-cooled chiller

    Directory of Open Access Journals (Sweden)

    Chung-Neng Huang

    2015-11-01

    Full Text Available Global warming and energy exhaustion problems are becoming a severe problems, of which energy conservation and carbon reduction are the most critical. Between 40% and 48% of the total electricity used in a building is consumed by air conditioning systems. The development of a supersonic water-misting cooling system with a fuzzy control system is proposed to optimize existing condenser noise, space, and energy consumption, as well as to address problems with cooling capacity resulting from improper control between compressors and condensers. An experimental platform was established for conducting tests, observing cooling efficiencies, and calculating power saving statuses. Comparing the observed cooling efficiency, a temperature difference of 5.4 °C was determined before and after the application; this is significant regarding efficiency. The method produces no pollution or water accumulation. When compared with fixed frequency air-cooled water chillers, an exceptional energy saving of 25% was observed. The newly developed supersonic mist-cooled chiller is an excellent solution to increasing water and electricity fees.

  11. Assessing energy efficiencies, economy, and global warming potential (GWP) effects of major crop production systems in Iran: a case study in East Azerbaijan province.

    Science.gov (United States)

    Mohammadzadeh, Arash; Mahdavi Damghani, Abdolmajid; Vafabakhsh, Javad; Deihimfard, Reza

    2017-07-01

    Efficient use of energy in farming systems is one of the most important implications for decreasing greenhouse gas (GHG) emissions and mitigating global warming (GW). This paper describes the energy use patterns, analyze the economics, and report global warming potential effects of major crop production systems in East Azerbaijan province, Iran. For this purpose, 110 farmers whose main activity was major crop production in the region, including wheat, barley, carrot, tomato, onion, potato, alfalfa, corn silage, canola, and saffron, were surveyed. Some other data was obtained from the Ministry of Agriculture Jihad of Iran. Results showed that, in terms of total energy input, onion (87,556 Mj ha -1 ) and potato (80,869 Mj ha -1 ) production systems were more energy-intensive than other crops. Among the studied crops, the highest values of net return (6563.8 $ ha -1 ) and benefit/cost ratio (1.95) were related to carrot and corn silage production systems, respectively. Studies have also shown that onion and saffron production systems emit the highest (5332.6 kg CO2eq ha -1 ) and lowest (646.24 kg CO 2 eq ha -1 ) CO 2 eq. emission, respectively. When it was averaged across crops, diesel fuel accounted for the greatest GHG contribution with 43% of the total, followed by electric power (28%) and nitrogen fertilizer (21%). In the present study, eco-efficiency was calculated as a ratio of the gross production value and global warming potential effect for the studied crops. Out of all the studied crops, the highest values of eco-efficiency were calculated to be 8.65 $ kg CO 2 eq -1 for the saffron production system followed by the carrot (3.65 $ kg CO 2 eq -1 ) production. Generally, from the aspect of energy balance and use efficiency, the alfalfa production system was the best; however, from an economical point of view, the carrot production system was better than the other crops.

  12. Guidance Optimization for Tactical Homing Missiles and Air Defense Systems

    Directory of Open Access Journals (Sweden)

    Yunes Sh. ALQUDSI

    2018-03-01

    Full Text Available The aim of this paper is to develop a functional approach to optimize the engagement effectiveness of the tactical homing missiles and air defense systems by utilizing the differential geometric concepts. In this paper the engagement geometry of the interceptor and the target is developed and expressed in differential geometric terms in order to demonstrate the possibilities of the impact triangles and specify the earliest interception based on the direct intercept geometry. Optimizing the missile heading angle and suitable missile velocity against the target velocity is then examined to achieve minimum missile latax, minimum time-to-go (time-to-hit and minimum appropriate missile velocity that is guaranteed a quick and precise interception for the given target. The study terminates with different scenarios of engagement optimization with two-dimensional simulation to demonstrate the applicability of the DG approach and to show its properties.

  13. Design of an online spot air sampling system

    International Nuclear Information System (INIS)

    Rath, D.P.; Govalkar, Atul; Yadav, S.A.; Mukherjee, Govinda; Murali, S.; Babu, D.A.R.; Prasad, R.S.

    2012-01-01

    In all the alpha handling facilities spot air sampling is essential while clearing a lab consequent to week end ventilation shut down or subsequent to completion of work/operations goes inside the facility. The sampling head is designed for 5 micron particles. Following pints are noticed over a period of such operational activities: Health Physicist goes inside a lab with a half face mask whose protection factor is 10, thereby useful for lab air activity up to ten DACs. Many times HP goes inside the lab when activity is more which is highly unsafe. On many occasions simultaneously a number of samples have to be taken by HP from a large number of laboratories inside the facility or for any special job where continuous radiological protection is required. Based on this it is proposed to design a sampling system which will overcome the above limitations. The design of the sampling head has been carried out which is for 5 micron particle size. The pump which is available in the existing facilities can be utilized. An innovative way of counting for large number of samples is fabricated in the RHC wing, RMD which can count ten samples at a time. Removal and counting of the sample may be carried out in a similar sampling carousel which is being used in RHC Unit, Radiometallurgy wing successfully with a little modification. In the proposed system, three samples can be operated in-line such that health physics intervention during the active operation would be minimum and during alarm situations (i.e. on the DAC level) proper protective equipment shall be advised by health physicist or he may suggest any other protective action. This type of online monitors will help in establishing the airborne activity inside the lab where special jobs are being carried out which will provide maximum protection to the lab personnel as well as to the health physicist who supervises the entire operation

  14. Changes in the daily range of the air temperature in the mountainous part of Slovakia within the possible context of global warming

    Directory of Open Access Journals (Sweden)

    Ingrid Damborská

    2016-02-01

    Full Text Available Mean global and regional air temperatures have increased in the last several decades more than at any time during the history of instrumental measurement. Because of changes in the energy balance of the daily regime of the Earth's surface, it seems that the daily minimum temperature will increase more than the daily maximum one. The general theoretical analysis have indicated the daily range (TR of air temperatures decrease, but they are also influenced by several other factors such as topography, wind, solar radiation, cloudiness, humidity, soil moisture, upwind and lee effects, etc. This paper contains a sample from an analysis of past conditions showing changes in TR at several Slovak stations from 1961–2010 and possible changes in TR up to the time frame of the year 2100 using climate change scenarios based on four climatic models adopted in Slovakia (global CGCM3.1 and ECHAM5, regional KNMI and MPI and three emission scenarios (IPCC SRES A2, B1 and A1B. The trends and correlations of daily air temperature ranges with other climatic variables were analyzed.

  15. Impacts of 1.5°C warming on high mountain systems: state of knowledge, challenges and the way forward

    Science.gov (United States)

    Huggel, Christian; Salzmann, Nadine; Allen, Simon; Frey, Holger; Haeberli, Wilfried; Linsbauer, Andreas; Paul, Frank

    2016-04-01

    Recently, both in science and policy, discussions have intensified about whether the 2°C 'guardrail' can really be considered a safety margin, i.e. natural and human systems would be reasonably safe when global warming can be limited to below 2°C with reference to preindustrial levels. Concerns about the 'safety' of the 2°C warming mounted especially with reference to highly vulnerable systems such as small islands, polar regions and high mountains where 2°C may imply crossing thresholds with major irreversible impacts. Several countries and organizations therefore called for a 1.5°C target, and it was one of the remarkable aspects of the Paris Climate Conference in December 2015 that 1.5°C was explicitly included in the Paris Agreement. However, scientifically, little is known about the difference between 1.5°C and 2°C warming in terms of impacts on natural and human systems. This was also corroborated by the final report of the UNFCCC Structured Expert Dialogue (SED) which was based on the outcomes of the IPCC 5th Assessment Report and subsequent expert discussions. Here we respond to this gap and challenge of understanding the differences of impacts as related to 1.5°C and 2°C above preindustrial levels. We concentrate on high mountains and impacts related to changes in the cryosphere because these systems are very sensitive to climatic changes (in particular to the key climate variables temperature and precipitation) and acknowledged as highly vulnerable areas. We start with a systematic literature review and find that the mountain research community has addressed this issue only in a marginal way. We then develop a conceptual but evidence-based model how this challenge could be addressed: We suggest to first study the changes and corresponding impacts seen in high mountain systems since the Little Ice Age focusing on specified periods with 0.5°C global warming (corresponding regional warming, for instance in the Swiss Alps, in these periods was

  16. AEC Regulatory view of the reliability of air cleaning systems in nuclear facilities

    International Nuclear Information System (INIS)

    Bellamy, R.R.; Zavadoski, R.W.

    1975-01-01

    Air cleaning systems in nuclear facilities can be divided into three categories: ventilation exhaust systems, containment atmosphere cleanup systems, and process offgas systems. These systems have been the subject of numerous reports, regulatory guides, discussions, and meetings. Some of the analyses have been critical of the operation and design of these air cleaning systems--in particular, the engineered safety features containment atmosphere cleanup systems. Although for the most part the criticism is applicable, and recognizing that there are a number of unresolved issues pertaining to gaseous waste management systems, there are data to show that air cleaning systems in use in nuclear facilities are performing their intended function. (U.S.)

  17. Measure Guideline: Supplemental Dehumidification in Warm-Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, A.

    2014-10-01

    This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load has been dramatically reduced. In older homes in warm-humid climates, cooling loads are typically high and cooling equipment runs a lot to cool the air. The cooling process also removes indoor moisture, reducing indoor relative humidity. However, at current residential code levels, and especially for above-code programs, sensible cooling loads have been so dramatically reduced that the cooling system does not run a lot to cool the air, resulting in much less moisture being removed. In these new homes, cooling equipment is off for much longer periods of time especially during spring/fall seasons, summer shoulder months, rainy periods, some summer nights, and some winter days. In warm-humid climates, those long off periods allow indoor humidity to become elevated due to internally generated moisture and ventilation air change. Elevated indoor relative humidity impacts comfort, indoor air quality, and building material durability. Industry is responding with supplemental dehumidification options, but that effort is really in its infancy regarding year-round humidity control in low-energy homes. Available supplemental humidity control options are discussed. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling and avoids adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.

  18. Measure Guideline: Supplemental Dehumidification in Warm-Humid Climates

    Energy Technology Data Exchange (ETDEWEB)

    Rudd, Armin [Building Science Corporation, Somerville, MA (United States)

    2014-10-01

    This document covers a description of the need and applied solutions for supplemental dehumidification in warm-humid climates, especially for energy efficient homes where the sensible cooling load has been dramatically reduced. Cooling loads are typically high and cooling equipment runs a lot to cool the air in older homes in warm-humid climates. The cooling process also removes indoor moisture, reducing indoor relative humidity. However, at current residential code levels, and especially for above-code programs, sensible cooling loads have been so dramatically reduced that the cooling system does not run a lot to cool the air, resulting in much less moisture being removed. In these new homes, cooling equipment is off for much longer periods of time especially during spring/fall seasons, summer shoulder months, rainy periods, some summer nights, and winter days. In warm-humid climates, those long-off periods allow indoor humidity to become elevated due to internally generated moisture and ventilation air change. Elevated indoor relative humidity impacts comfort, indoor air quality, and building material durability. Industry is responding with supplemental dehumidification options, but that effort is really in its infancy regarding year-round humidity control in low-energy homes. Available supplemental humidity control options are discussed. Some options are less expensive but may not control indoor humidity as well as more expensive and comprehensive options. The best performing option is one that avoids overcooling and adding unnecessary heat to the space by using waste heat from the cooling system to reheat the cooled and dehumidified air to room-neutral temperature.

  19. Amplified Arctic warming by phytoplankton under greenhouse warming.

    Science.gov (United States)

    Park, Jong-Yeon; Kug, Jong-Seong; Bader, Jürgen; Rolph, Rebecca; Kwon, Minho

    2015-05-12

    Phytoplankton have attracted increasing attention in climate science due to their impacts on climate systems. A new generation of climate models can now provide estimates of future climate change, considering the biological feedbacks through the development of the coupled physical-ecosystem model. Here we present the geophysical impact of phytoplankton, which is often overlooked in future climate projections. A suite of future warming experiments using a fully coupled ocean-atmosphere model that interacts with a marine ecosystem model reveals that the future phytoplankton change influenced by greenhouse warming can amplify Arctic surface warming considerably. The warming-induced sea ice melting and the corresponding increase in shortwave radiation penetrating into the ocean both result in a longer phytoplankton growing season in the Arctic. In turn, the increase in Arctic phytoplankton warms the ocean surface layer through direct biological heating, triggering additional positive feedbacks in the Arctic, and consequently intensifying the Arctic warming further. Our results establish the presence of marine phytoplankton as an important potential driver of the future Arctic climate changes.

  20. Global warming impacts of chillers

    International Nuclear Information System (INIS)

    Calm, J.M.

    1993-01-01

    Most discussion of refrigerant impacts on the environment has focused on protection of stratospheric ozone. The now-familiar Montreal Protocol, as revised last November at a meeting in Copenhagen, provides a clear mandate for transition to alternatives that do not deplete the earth's ozone layer. Coupled with reduction in refrigerant emissions, substitution of fluids with low or zero ozone-depletion potential (ODP) minimize or, for the latter, eliminate damage to the ozone layer. With retirement of the chlorofluorocarbon (CFC) refrigerants that once dominated in chillers for air conditioning systems, including r-11, R-12, R-113, R-114, and R-500 (which contains R-12), questions surface on other environmental concerns for the alternatives. The direct effect (chemical action as a greenhouse gas) alone however, is misleading. The thermodynamic properties of a refrigerant limit the efficiency that can be attained in a heat pump or refrigeration machine. Since the efficiency governs the amount of power required for a specific thermal load, the selection refrigerants also impacts the greenhouse gases, most notably carbon dioxide, released in supplying the required power. The warming stemming from combustion emissions to provide power is referred to as the indirect, or energy-related, effect. Atmospheric scientists use the term indirect effect to refer to the impact of greenhouse gases produced in the atmosphere by chemical reactions with an emission. The effect of this secondary chemistry is of much lesser magnitude and is not further discussed in this article