Science.gov

Sample records for measures mitigating heat

  1. Heat Island Mitigation Measures in Response to Climate Change Impacts

    NASA Technical Reports Server (NTRS)

    Quattrochi, Dale a.; Estes, Maurice, Jr.; Crosson, William; Al-Hamdan, Mohammad

    2010-01-01

    This slide presentation examines the effect of cities, the accompanying heat island effect, and other impacts that urbanization has had on the environment. Various satellite views of several urban areas are shown.

  2. Secondary effects of urban heat island mitigation measures on air quality

    NASA Astrophysics Data System (ADS)

    Fallmann, Joachim; Forkel, Renate; Emeis, Stefan

    2016-01-01

    This study presents numerical simulations analysing the effect of urban heat island (UHI) mitigation measures on the chemical composition of the urban atmosphere. The mesoscale chemical transport model WRF-Chem is used to investigate the impact of urban greening and highly reflective surfaces on the concentrations of primary (CO, NO) as well as secondary pollutants (O3) inside the urban canopy. In order to account for the sub-grid scale heterogeneity of urban areas, a multi-layer urban canopy model is coupled to WRF-Chem. Using this canopy model at its full extend requires the introduction of several urban land use classes in WRF-Chem. The urban area of Stuttgart serves as a test bed for the modelling of a case scenario of the 2003 European Heat Wave. The selected mitigation measures are able to reduce the urban temperature by about 1 K and the mean ozone concentration by 5-8%. Model results however document also negative secondary effects on urban air quality, which are closely related to a decrease of vertical mixing in the urban boundary layer. An increase of primary pollutants NO and CO by 5-25% can be observed. In addition, highly reflective surfaces can increase peak ozone concentration by up to 12% due to a high intensity of reflected shortwave radiation accelerating photochemical reactions.

  3. Mitigation Measures Following a Loss-of-Residual-Heat-Removal Event During Shutdown

    SciTech Connect

    Seul, Kwang Won; Bang, Young Seok; Kim, Hho Jung

    2000-10-15

    The transient following a loss-of-residual-heat-removal event during shutdown was analyzed to determine the containment closure time (CCT) to prevent uncontrolled release of fission products and the gravity-injection path and rate (GIPR) for effective core cooling using the RELAP5/MOD3.2 code. The plant conditions of Yonggwang Units 3 and 4, a pressurized water reactor (PWR) of 2815-MW(thermal) power in Korea, were reviewed, and possible event sequences were identified. From the CCT analysis for the five cases of typical plant configurations, it was estimated for the earliest CCT to be 40 min after the event in a case with a large cold-leg opening and emptied steam generators (SGs). However, the case with water-filled SGs significantly delayed the CCT through the heat removal to the secondary side. From the GIPR analysis for the six possible gravity-injection paths from the refueling water storage tank (RWST), the case with the injection point and opening on the other leg side was estimated to be the most suitable path to avoid core boiling. In addition, from the sensitivity study, it was evaluated for the plant to be capable of providing the core cooling for the long-term transient if nominal RWST water is available. As a result, these analysis methods and results will provide useful information in understanding the plant behavior and preparing the mitigation measures after the event, especially for Combustion Engineering-type PWR plants. However, to directly apply the analysis results to the emergency procedure for such an event, additional case studies are needed for a wide range of operating conditions such as reactor coolant inventory, RWST water temperature, and core decay heat rate.

  4. Composition and sources of PM2.5 around the heating periods of 2013 and 2014 in Beijing: Implications for efficient mitigation measures

    NASA Astrophysics Data System (ADS)

    Yang, Hainan; Chen, Jing; Wen, Jiaojiao; Tian, Hezhong; Liu, Xingang

    2016-01-01

    The diurnal variations of the water soluble organic and inorganic components as well as six selected metals in PM2.5 around the heating periods of 2013 and 2014 in Beijing were analyzed in this study to investigate the contributions of secondary aerosols and primary pollutants to PM2.5 and the effects of domestic heating and mitigation measures. The before-heating sampling period in 2014 (from Nov. 1st to Nov. 15th) was characterized with reinforced short-term mitigation measures for the 2014 Asia-Pacific Economic Cooperation (APEC) meeting. As a result, the average mass concentrations of PM2.5 and most of the measured species except for Cu, Al, and Ca2+ were greatly reduced during the APEC meeting period. The domestic heating activity alone resulted in a 17.7% increase of PM2.5 in 2013, exerting lesser effects on the increase of PM2.5 than before. Water soluble organic carbon was the most abundant water soluble species in PM2.5, followed by NO3-, SO42-, and NH4+ . According to the PMF model calculation, secondary aerosols, coal combustion, biomass/waste burning, traffic related pollution, long-range transport, and fugitive soil and sand dust were identified as the main sources of PM2.5 in Beijing, among which secondary formation of aerosols was the dominant source of PM2.5 during the non-APEC period while biomass/waste burning dominated during the APEC period. As a timely feedback on the effects of the mitigation measures adopted by the government, the results of this study provide knowledge necessary for a sustainable urban management.

  5. Mesoscale thermal model for urban heat island mitigation

    NASA Astrophysics Data System (ADS)

    Silva, Humberto Ramon

    A simple energy balance model is created for use in developing mitigation strategies for the Urban Heat Island (UHI) effect. The model is applied to the city of Phoenix, Arizona, USA. There are six primary contributions to the overall energy balance: incident solar radiation, anthropogenic heat input, conduction heat loss, outgoing evapotranspiration, outgoing convection, and outgoing emitted radiation. The model temperature is shown to have the same periodic behavior as the experimentally measured air temperatures. The present model, while maintaining valid energy-balance physics, allows users to quickly and easily predict the relative effects of urban heat island mitigation measures. Accordingly, this model is applied here to show the relative effects of four common mitigation strategies: increasing the overall (1) emissivity, (2) percentage of vegetated area, (3) thermal conductivity, and (4) albedo of the urban environment in a series of percentage increases by 5, 10, 15, and 20 percent from baseline values. In addition to modeling mitigation strategies, the model is utilized to evaluate human health vulnerability from excessive heat-related events, based on heat-related emergency service data from 2002 to 2006. The four modeled UHI mitigation strategies, taken in combination, would lead to a 48 percent reduction in annual heat-related emergency service calls, where increasing the albedo is the single most effective UHI mitigation strategy. Finally, a spatial superposition design is presented that couples this model with the more robust fifth-generation Pennsylvania State University - National Center for Atmospheric Research Mesoscale Model (MM5). As a result, a new hypothesis is conceived which states that perturbation values from the norm temperature do not change when certain mitigation strategies are imposed. It is shown from demonstrative spatial mitigation schemes that having a fewer number of mitigated points (by almost half) on a square urban grid in

  6. Pre-heating mitigates composite degradation

    PubMed Central

    da SILVA, Jessika Calixto; Rogério Vieira, REGES; REGE, Inara Carneiro Costa; CRUZ, Carlos Alberto dos Santos; VAZ, Luís Geraldo; ESTRELA, Carlos; de CASTRO, Fabrício Luscino Alves

    2015-01-01

    ABSTRACT Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey’s tests (α=5%). Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth. PMID:26814459

  7. Pre-heating mitigates composite degradation.

    PubMed

    Silva, Jessika Calixto da; Rogério Vieira, Reges; Rege, Inara Carneiro Costa; Cruz, Carlos Alberto dos Santos; Vaz, Luís Geraldo; Estrela, Carlos; Castro, Fabrício Luscino Alves de

    2015-01-01

    Dental composites cured at high temperatures show improved properties and higher degrees of conversion; however, there is no information available about the effect of pre-heating on material degradation. Objectives This study evaluated the effect of pre-heating on the degradation of composites, based on the analysis of radiopacity and silver penetration using scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDS). Material and Methods Thirty specimens were fabricated using a metallic matrix (2x8 mm) and the composites Durafill VS (Heraeus Kulzer), Z-250 (3M/ESPE), and Z-350 (3M/ESPE), cured at 25°C (no pre-heating) or 60°C (pre-heating). Specimens were stored sequentially in the following solutions: 1) water for 7 days (60°C), plus 0.1 N sodium hydroxide (NaOH) for 14 days (60°C); 2) 50% silver nitrate (AgNO3) for 10 days (60°C). Specimens were radiographed at baseline and after each storage time, and the images were evaluated in gray scale. After the storage protocol, samples were analyzed using SEM/EDS to check the depth of silver penetration. Radiopacity and silver penetration data were analyzed using ANOVA and Tukey's tests (α=5%). Results Radiopacity levels were as follows: Durafill VSZ-350>Z-250 (p<0.05). After storage in water/NaOH, pre-heated specimens presented higher radiopacity values than non-pre-heated specimens (p<0.05). There was a lower penetration of silver in pre-heated specimens (p<0.05). Conclusions Pre-heating at 60°C mitigated the degradation of composites based on analysis of radiopacity and silver penetration depth. PMID:26814459

  8. Heat waves in urban heat islands: interactions, impacts, and mitigation

    NASA Astrophysics Data System (ADS)

    Bou-Zeid, E.; Li, D.

    2013-12-01

    Urbanization rates and the intensity of anthropogenic global warming are both on the rise. By the middle of this century, climate change impacts on humans will be largely manifested in urban regions and will result from a combination of global to regional impacts related to greenhouse gas emissions, as well as regional to local impacts related to land-cover changes associated with urbanization. Alarmingly, our understanding of how these two distinct impacts will interact remains very poor. One example, which is the focus of this study, is the interaction of urban heat islands and heat waves. Urban heat islands (UHIs) are spatial anomalies consisting of higher temperatures over built terrain; while their intensity varies with many factors, it consistently increases with city size. UHIs will hence intensify in the future as cities expand. Heat waves are temporal anomalies in the regional temperatures that affect both urban and rural areas; there is high certainty that the frequency and intensity of such waves will increase as a result global warming. However, whether urban and rural temperatures respond in the same way to heat waves remains a critical unanswered question. In this study, a combination of observational and modeling analyses of a heat wave event over the Baltimore-Washington urban corridor reveals synergistic interactions between urban heat islands and heat waves. Not only do heat waves increase the regional temperatures, but they also intensify the difference between urban and rural temperatures. That is, their impact is stronger in cities and the urban heat stress during such waves is larger than the sum of the background urban heat island effect and the heat wave effect. We also develop a simple analytical model of this interaction that suggests that this exacerbated impact in urban areas is primarily to the lack of surface moisture, with low wind speeds also playing a smaller role. Finally, the effectiveness of cool and green roofs as UHI mitigation

  9. Bioenergy as a Mitigation Measure

    NASA Astrophysics Data System (ADS)

    Dass, P.; Brovkin, V.; Müller, C.; Cramer, W.

    2011-12-01

    Numerous studies have shown that bioenergy, being one of the renewable energies with the lowest costs, is expected to play an important role in the near future as climate change mitigation measure. Current practices of converting crop products such as carbohydrates or plant oils to ethanol or biodiesel have limited capabilities to curb emission. Moreover, they compete with food production for the most fertile lands. Thus, second generation bioenergy technologies are being developed to process lignocellulosic plant materials from fast growing tree and grass species. A number of deforestation experiments using Earth System models have shown that in the mid- to high latitudes, deforested surface albedo strongly increases in presence of snow. This biophysical effect causes cooling, which could dominate over the biogeochemical warming effect because of the carbon emissions due to deforestation. In order to find out the global bioenergy potential of extensive plantations in the mid- to high latitudes, and the resultant savings in carbon emissions, we use the dynamic global vegetation model LPJmL run at a high spatial resolution of 0.5°. It represents both natural and managed ecosystems, including the cultivation of cellulosic energy crops. LPJmL is run with 21st century projections of climate and atmospheric CO2 concentration based on the IPCC-SRES business as usual or A2 scenario. Latitudes above 45° in both hemispheres are deforested and planted with crops having the highest bioenergy return for the respective pixels of the model. The rest of the Earth has natural vegetation. The agricultural management intensity values are used such that it results in the best approximation for 1999 - 2003 national yields of wheat and maize as reported by FAOSTAT 2009. Four different scenarios of land management are used ranging from an idealistic or best case scenario, where all limitations of soil and terrain properties are managed to the worst case scenario where none of these

  10. Measurements of Impurity and Heat Dynamics During Noble Gas Jet-Initiated Fast Plasma Shutdown for Disruption Mitigation in DIII-D

    SciTech Connect

    Hollmann, E M; Jernigan, T C; Groth, M; Whyte, D G; Gray, D S; Brennan, D P; Brooks, N H; Evans, T E; Humphreys, D A; Lasnier, C J; Moyer, R A; McClean, A; Parks, P B; Rozhansky, V; Rudakov, D L; Strait, E J; West, W P

    2004-12-01

    Impurity deposition and mixing during gas jet-initiated plasma shutdown is studied using a rapid ({approx}2 ms), massive ({approx}10{sup 22} particles) injection of neon or argon into stationary DIII-D H-mode discharges. Fast-gated camera images indicate that the bulk of the jet neutrals do not penetrate far into the plasma pedestal. Nevertheless, high ({approx}90%) thermal quench radiated power fractions are achieved; this appears to be facilitated through a combination of fast ion mixing and fast heat transport, both driven by large-scale MHD activity. Also, runaway electron suppression is achieved for sufficiently high gas jet pressures. These experiments suggest that massive gas injection could be viable for disruption mitigation in future tokamaks even if core penetration of jet neutrals is not achieved.

  11. The Urban Heat Island Phenomenon and Potential Mitigation Strategies

    NASA Technical Reports Server (NTRS)

    Estes, Maurice G., Jr.; Gorsevski, Virginia; Russell, Camille; Quattrochi, Dale; Luvall, Jeffrey

    1999-01-01

    A survey of urban heat island research is provided to describe how heat islands develop, urban landscape and meteorological characteristics that facilitate development, use of aircraft remote sensing data, and why heat islands are of interest to planners, elected officials, and the public. The roles of the National Aeronautics and Space Administration (NASA), the Environmental Protection Agency (EPA), other federal agencies, national laboratories and universities, state and local governments, and non-governmental organizations (NGOS) in studying the urban heat island effect and developing mitigation strategies are explored. Barriers that hamper mitigation efforts and case studies in Atlanta and Salt Lake City are discussed.

  12. Paving materials for heat island mitigation

    SciTech Connect

    Pomerantz, M.; Akbari, H.; Chen, A.; Taha, H.; Rosenfeld, A.H.

    1997-11-01

    This report summarizes paving materials suitable for urban streets, driveways, parking lots and walkways. The authors evaluate materials for their abilities to reflect sunlight, which will reduce their temperatures. This in turn reduces the excess air temperature of cities (the heat island effect). The report presents the compositions of the materials, their suitability for particular applications, and their approximate costs (in 1996). Both new and resurfacing are described. They conclude that, although light-colored materials may be more expensive than conventional black materials, a thin layer of light-colored pavement may produce energy savings and smog reductions whose long-term worth is greater than the extra cost.

  13. Space debris mitigation measures in India

    NASA Astrophysics Data System (ADS)

    Adimurthy, V.; Ganeshan, A. S.

    2006-02-01

    The Indian Space Research Organization (ISRO) recognizes the importance of the current space debris scenario, and the impact it has on the effective utilization of space technology for the improvement in the quality of life on the Earth. ISRO is committed to effective management of the threats due to space debris. Towards this commitment ISRO works on different aspects of space debris, including the debris mitigation measures. This paper highlights the activities and achievements in the implementation of the mitigation measures. ISRO successfully designed and developed a propellant venting system for implementation in the existing upper stage of India's Polar Satellite Launch Vehicle (PSLV), which uses Earth-storable liquid propellants. GSLV also employs passivation of the Cryogenic Upper Stage at the end of its useful mission. ISRO's communication satellites in GSO are designed with adequate propellant margins for re-orbiting at the end of their useful life to a higher graveyard orbit. A typical successful operation in connection with INSAT-2C is described. ISRO developed its debris environmental models and software to predict the close approach of any of the debris to the functional satellites. The software are regularly used for the debris risk management of the orbiting spacecraft and launch vehicles. ISRO recognizes the role of international cooperation in the debris mitigation measures and actively contributes to the efforts of the Inter-Agency Space Debris Coordination Committee (IADC) and United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS).

  14. Mitigation measures and programs in Hungary

    SciTech Connect

    Molnar, S.

    1996-12-31

    In Hungary there are four main governmental programs, which may result in a decrease of emissions of anthropogenic greenhouse gases (GHGs): (1) National program of energy efficiency improvement and energy conservation, (2) Afforestation program, (3) Volatile organic compounds (VOC) emission reduction program, and (4) Program to reduce the use of ozone depleting substances. These ambitious programs were launched in the beginning of the 90`s, but they have been slowed down because of budgetary problems. The comprehensive action plan for mitigation of GHG emissions should be based on these ongoing programs. These programs should be expanded by further measures and programs in order to fulfill the requirements of the FCCC. In the next sections the results and prospects of the above mentioned programs will be summarized. Also the results of the mitigation study supported by the U.S. Country Studies Program are included.

  15. 13 CFR 123.21 - What is a mitigation measure?

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 13 Business Credit and Assistance 1 2011-01-01 2011-01-01 false What is a mitigation measure? 123.21 Section 123.21 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION DISASTER LOAN PROGRAM Overview § 123.21 What is a mitigation measure? A mitigation measure is something done for the purpose...

  16. Heat flux measurements

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Weikle, Donald H.

    1989-01-01

    A new automated, computer controlled heat flux measurement facility is described. Continuous transient and steady-state surface heat flux values varying from about 0.3 to 6 MW/sq m over a temperature range of 100 to 1200 K can be obtained in the facility. An application of this facility is the development of heat flux gauges for continuous fast transient surface heat flux measurement on turbine blades operating in space shuttle main engine turbopumps. The facility is useful for durability testing at fast temperature transients.

  17. Characterization of heat loads from mitigated and unmitigated vertical displacement events in DIII-D

    SciTech Connect

    Hollmann, E. M.; Moyer, R. A.; Commaux, N.; Jernigan, T. J.; Eidietis, N. W.; Humphreys, D. A.; Strait, E. J.; Wesley, J. C.; Lasnier, C. J.; Pitts, R. A.; Sugihara, M.; Watkins, J.

    2013-06-15

    Experiments have been conducted on the DIII-D tokamak to study the distribution and repeatability of heat loads and vessel currents resulting from vertical displacement events (VDEs). For unmitigated VDEs, the radiated power fraction appears to be of order 50%, with the remaining power dominantly conducted to the vessel walls. Shot-to-shot scatter in heat loads measured at one toroidal location is not large (<±50%), suggesting that toroidal asymmetries in conducted heat loads are not large. Conducted heat loads are clearly observed during the current quench (CQ) of both mitigated and unmitigated disruptions. Significant poloidal asymmetries in heat loads and radiated power are often observed in the experiments but are not yet understood. Energy dissipated resistively in the conducting walls during the CQ appears to be small (<5%). The mitigating effect of neon massive gas injection (MGI) as a function of MGI trigger delay has also been studied. Improved mitigation is observed as the MGI trigger delay is decreased. For sufficiently early MGI mitigation, close to 100% radiated energy and a reduction of roughly a factor 2 in vessel forces is achieved.

  18. Planetary heat flow measurements.

    PubMed

    Hagermann, Axel

    2005-12-15

    The year 2005 marks the 35th anniversary of the Apollo 13 mission, probably the most successful failure in the history of manned spaceflight. Naturally, Apollo 13's scientific payload is far less known than the spectacular accident and subsequent rescue of its crew. Among other instruments, it carried the first instrument designed to measure the flux of heat on a planetary body other than Earth. The year 2005 also should have marked the launch of the Japanese LUNAR-A mission, and ESA's Rosetta mission is slowly approaching comet Churyumov-Gerasimenko. Both missions carry penetrators to study the heat flow from their target bodies. What is so interesting about planetary heat flow? What can we learn from it and how do we measure it?Not only the Sun, but all planets in the Solar System are essentially heat engines. Various heat sources or heat reservoirs drive intrinsic and surface processes, causing 'dead balls of rock, ice or gas' to evolve dynamically over time, driving convection that powers tectonic processes and spawns magnetic fields. The heat flow constrains models of the thermal evolution of a planet and also its composition because it provides an upper limit for the bulk abundance of radioactive elements. On Earth, the global variation of heat flow also reflects the tectonic activity: heat flow increases towards the young ocean ridges, whereas it is rather low on the old continental shields. It is not surprising that surface heat flow measurements, or even estimates, where performed, contributed greatly to our understanding of what happens inside the planets. In this article, I will review the results and the methods used in past heat flow measurements and speculate on the targets and design of future experiments. PMID:16286290

  19. Latent Heat in Soil Heat Flux Measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, the...

  20. Structural master plan of flood mitigation measures

    NASA Astrophysics Data System (ADS)

    Heidari, A.

    2009-01-01

    Flood protection is one of the practical methods in damage reduction. Although it not possible to be completely protected from flood disaster but major part of damages can be reduced by mitigation plans. In this paper, the optimum flood mitigation master plan is determined by economic evaluation in trading off between the construction costs and expected value of damage reduction as the benefits. Size of the certain mitigation alternative is also be obtained by risk analysis by accepting possibility of flood overtopping. Different flood mitigation alternatives are investigated from various aspects in the Dez and Karun river floodplain areas as a case study in south west of IRAN. The results show that detention dam and flood diversion are the best alternatives of flood mitigation methods as well as enforcing the flood control purpose of upstream multipurpose reservoirs. Dyke and levees are not mostly justifiable because of negative impact on down stream by enhancing routed flood peak discharge magnitude and flood damages as well.

  1. FOLLOW-UP RADON MEASUREMENTS IN 14 MITIGATED SCHOOLS

    EPA Science Inventory

    The report gives results of a determination of the long-term performance of radon mitigation systems installed in U. S. EPA research schools: radon measurements were conducted in 14 schools that had been mitigated between 1988 and 1991. he measurements were made between February ...

  2. FOLLOW-UP RADON MEASUREMENTS IN 14 MITIGATED SCHOOLS

    EPA Science Inventory

    The report gives results of a determination of the long-term performance of radon mitigation systems installed in U. S. EPA research schools: radon measurements were conducted in 14 schools that had been mitigated between 1988 and 1991. The measurements were made between Februar...

  3. 43 CFR 46.130 - Mitigation measures in analyses.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 43 Public Lands: Interior 1 2011-10-01 2011-10-01 false Mitigation measures in analyses. 46.130... Mitigation measures in analyses. (a) Bureau proposed action. The analysis of the proposed action and any alternatives must include an analysis of the effects of the proposed action or alternative as well as...

  4. Understanding and mitigating heat exchanger fouling in bauxite refineries

    NASA Astrophysics Data System (ADS)

    Müller-Steinhagen, H.; Jamialahmadi, M.; Robson, B.

    1994-11-01

    Laboratory and plant measurements have been performed to evaluate possibilities of reducing the formation of desilication product (DSP) scale in the heat exchangers of the low-temperature Bayer process. It was found that the rate of scale formation is independent of the flow velocity, proportional to the square of the silica super saturation, and it increases exponentially with heat-transfer surface temperature. Because of the restricted operation conditions, variation of operating conditions may not reduce DSP formation sufficiently. Installation of turbulence promoters in the heat exchanger pipes had no beneficial aspects. Laboratory and plant measurements with a fluidized bed test heater indicated a strong potential of this technology to increase the operation times between chemical washes. Deposition of DSP could almost be eliminated if the process was modified such that developed subcooled boiling occurred at the heat-transfer surface.

  5. Mitigation of urban heat islands: meteorology, energy, and airquality impacts

    SciTech Connect

    Taha, Haider; Meier, Alan; Gao, Weijun; Ojima, Toshio

    1999-09-30

    This paper presents results from energy, meteorological andphotochemical (air quality) modeling for the Los Angeles Basin, one ofthe largest and smoggiest urban regions in the U.S. and the world. Oursimulations suggest that by mitigating urban heat islands, savings of 5to 10 percent peak utility load may be possible. In addition, heat islandmitigation can reduce smog formation by 10-20 percent. in summer, whichis as effective as controlling emissions from all mobile sources in theregion. For a typical late-August episode, our simulations suggest thatimplementing cool cities in the Los Angeles Basin would have a net effectof reducing ozone concentrations. Peak concentrations at 3 pm decrease byup to 7 percent (from 220 down to 205 ppb) while the total ozone mass inthe mixed layer decreases by up to 640 metric tons (a decrease of 4.7percent). Largest reductions in concentrations at 3 pm are on the orderof 50 ppb whereas the largest increases are on the order of 20 ppb. Withrespect to the National Ambient Air Quality Standard, domain widepopulation weighted exceedance exposure to ozone decreases by up to 20percent during peak afternoon hours and by up to 10 percent during thedaytime.

  6. Mitigation technologies and measures in energy sector of Kazakstan

    SciTech Connect

    Pilifosova, O.; Danchuk, D.; Temertekov, T.

    1996-12-31

    An important commitment in the UN Framework Convention on Climate Change is to conduct mitigation analysis and to communicate climate change measures and policies. In major part reducing CO{sub 2} as well as the other greenhouse gas emissions in Kazakstan, can be a side-product of measures addressed to increasing energy efficiency. Since such measures are very important for the national economy, mitigation strategies in the energy sector of Kazakstan are directly connected with the general national strategy of the energy sector development. This paper outlines the main measures and technologies in energy sector of Kazakstan which can lead to GHG emissions reduction and presents the results of current mitigation assessment. The mitigation analysis is addressed to energy production sector. A baseline and six mitigation scenarios were developed to evaluate the most attractive mitigation options, focusing on specific technologies which have been already included in sustainable energy programs. According to the baseline projection, Kazakstan`s CO{sub 2} emissions will not exceed their 1990 level until 2005. The potential for CO{sub 2} emission reduction is estimated to be about 11 % of the base line emission level by the end of considered period (in 2020). The main mitigation options in the energy production sector in terms of mitigation potential and technical and economical feasibility include rehabilitation of thermal power plants aimed to increasing efficiency, use of nuclear energy and further expansion in the use of hydro energy based on small hydroelectric power plants.

  7. 43 CFR 46.130 - Mitigation measures in analyses.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Mitigation measures in analyses. (a) Bureau proposed action. The analysis of the proposed action and any alternatives must include an analysis of the effects of the proposed action or alternative as well as analysis... discussion of mitigation. (b) Applicant proposals (i.e., bureau decision-making on such proposals is...

  8. 43 CFR 46.130 - Mitigation measures in analyses.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Mitigation measures in analyses. (a) Bureau proposed action. The analysis of the proposed action and any alternatives must include an analysis of the effects of the proposed action or alternative as well as analysis... discussion of mitigation. (b) Applicant proposals (i.e., bureau decision-making on such proposals is...

  9. 43 CFR 46.130 - Mitigation measures in analyses.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Mitigation measures in analyses. (a) Bureau proposed action. The analysis of the proposed action and any alternatives must include an analysis of the effects of the proposed action or alternative as well as analysis... discussion of mitigation. (b) Applicant proposals (i.e., bureau decision-making on such proposals is...

  10. 43 CFR 46.130 - Mitigation measures in analyses.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Mitigation measures in analyses. (a) Bureau proposed action. The analysis of the proposed action and any alternatives must include an analysis of the effects of the proposed action or alternative as well as analysis... discussion of mitigation. (b) Applicant proposals (i.e., bureau decision-making on such proposals is...

  11. Air pollution prevention through urban heat island mitigation: An update on the urban heat island pilot project

    SciTech Connect

    Gorsevski, V.; Taha, H.; Quattrochi, D.; Luvall, J.

    1998-07-01

    Urban heat islands increase the demand for cooling energy and accelerate the formation of smog. They are created when natural vegetation is replaced by heat-absorbing surfaces such as building roofs and walls, parking lots, and streets. Through the implementation of measures designed to mitigate the urban heat island, communities can decrease their demand for energy and effectively cool the metropolitan landscape. In addition to the economic benefits, using less energy leads to reductions in emission of CO{sub 2}--a greenhouse gas--as well as ozone (smog) precursors such as NOx and VOCs. Because ozone is created when NOx and VOCs photochemically combine with heat and solar radiation, actions taken to lower ambient air temperature can significantly reduce ozone concentrations in certain areas. Measures to reverse the urban heat island include afforestation and the widespread use of highly reflective surfaces. To demonstrate the potential benefits of implementing these measures, EPA has teamed up with NASA and LBNL to initiate a pilot project with three US cities. As part of the pilot, NASA will use remotely-sensed data to quantify surface temperature, albedo, the thermal response number and NDVI vegetation of each city. This information will be used by scientists at Lawrence Berkeley National Laboratory (LBNL) along with other data as inputs to model various scenarios that will help quantify the potential benefits of urban heat island mitigation measures in terms of reduced energy use and pollution. This paper will briefly describe this pilot project and provide an update on the progress to date.

  12. Fundamentals of heat measurement. [heat flux transducers

    NASA Technical Reports Server (NTRS)

    Gerashchenko, O. A.

    1979-01-01

    Various methods and devices for obtaining experimental data on heat flux density over wide ranges of temperature and pressure are examined. Laboratory tests and device fabrication details are supplemented by theoretical analyses of heat-conduction and thermoelectric effects, providing design guidelines and information relevant to further research and development. A theory defining the measure of correspondence between transducer signal and the measured heat flux is established for individual (isolated) heat flux transducers subject to space and time-dependent loading. An analysis of the properties of stacked (series-connected) transducers of various types (sandwich-type, plane, and spiral) is used to derive a similarity theory providing general governing relationships. The transducers examined are used in 36 types of derivative devices involving direct heat loss measurements, heat conduction studies, radiation pyrometry, calorimetry in medicine and industry and nuclear reactor dosimetry.

  13. Measuring the Heats of Water.

    ERIC Educational Resources Information Center

    Hunt, James L.; Tegart, Tracy L.

    1994-01-01

    Uses common equipment (tea kettle and vacuum bottles) to precisely measure the specific heat, latent heat of fusion, and latent heat of vaporization of water. Provides descriptions for all three experiments. (MVL)

  14. Flicker Detection, Measurement and Means of Mitigation: A Review

    NASA Astrophysics Data System (ADS)

    Virulkar, V. B.; Aware, M. V.

    2014-04-01

    The voltage fluctuations caused by rapid industrial load change have been a major concern for supply utilities, regulatory agencies and customers. This paper gives a general review about how to examine/assess voltage flicker and methods followed in measuring the flickers due to rapid changing loads and means for its mitigation. It discusses the effects on utilities conditions, compensators response time and compensator capacity of flicker mitigation. A comparison between conventional mitigation techniques and the state-of-art mitigation techniques are carried out. It is shown in many cases that the state-of-art solution provides higher performance compared with conventional mitigation techniques. However, the choice of most suitable solution depends on characteristics of the supply at the point of connection, the requirement of the load and economics.

  15. Divertor Heat Flux Mitigation in the National Spherical Torus Experiment

    SciTech Connect

    Soukhanovskii, V A; Maingi, R; Gates, D A; Menard, J E; Paul, S F; Raman, R; Roquemore, A L; Bell, M G; Bell, R E; Boedo, J A; Bush, C E; Kaita, R; Kugel, H W; LeBlanc, B P; Mueller, D

    2008-08-04

    Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly-shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono et al., Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m{sup -2} to 0.5-2 MW m{sup -2} in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.

  16. Divertor heat flux mitigation in the National Spherical Torus Experiment

    SciTech Connect

    Soukhanovskii, V. A.; Maingi, R.; Gates, D.A.; Menard, J.E.; Bush, C.E.

    2009-01-01

    Steady-state handling of divertor heat flux is a critical issue for both ITER and spherical torus-based devices with compact high power density divertors. Significant reduction of heat flux to the divertor plate has been achieved simultaneously with favorable core and pedestal confinement and stability properties in a highly shaped lower single null configuration in the National Spherical Torus Experiment (NSTX) [M. Ono , Nucl. Fusion 40, 557 2000] using high magnetic flux expansion at the divertor strike point and the radiative divertor technique. A partial detachment of the outer strike point was achieved with divertor deuterium injection leading to peak flux reduction from 4-6 MW m(-2) to 0.5-2 MW m(-2) in small-ELM 0.8-1.0 MA, 4-6 MW neutral beam injection-heated H-mode discharges. A self-consistent picture of the outer strike point partial detachment was evident from divertor heat flux profiles and recombination, particle flux and neutral pressure measurements. Analytic scrape-off layer parallel transport models were used for interpretation of NSTX detachment experiments. The modeling showed that the observed peak heat flux reduction and detachment are possible with high radiated power and momentum loss fractions, achievable with divertor gas injection, and nearly impossible to achieve with main electron density, divertor neutral density or recombination increases alone.

  17. Social and ethical perspectives of landslide risk mitigation measures

    NASA Astrophysics Data System (ADS)

    Kalsnes, Bjørn; Vangelsten, Bjørn V.

    2015-04-01

    Landslide risk may be mitigated by use of a wide range of measures. Mitigation and prevention options may include (1) structural measures to reduce the frequency, severity or exposure to the hazard, (2) non-structural measures, such as land-use planning and early warning systems, to reduce the hazard frequency and consequences, and (3) measures to pool and transfer the risks. In a given situation the appropriate system of mitigation measures may be a combination of various types of measures, both structural and non-structural. In the process of choosing mitigation measures for a given landslide risk situation, the role of the geoscientist is normally to propose possible mitigation measures on basis of the risk level and technical feasibility. Social and ethical perspectives are often neglected in this process. However, awareness of the need to consider social as well as ethical issues in the design and management of mitigating landslide risk is rising. There is a growing understanding that technical experts acting alone cannot determine what will be considered the appropriate set of mitigation and prevention measures. Issues such as environment versus development, questions of acceptable risk, who bears the risks and benefits, and who makes the decisions, also need to be addressed. Policymakers and stakeholders engaged in solving environmental risk problems are increasingly recognising that traditional expert-based decision-making processes are insufficient. This paper analyse the process of choosing appropriate mitigation measures to mitigate landslide risk from a social and ethical perspective, considering technical, cultural, economical, environmental and political elements. The paper focus on stakeholder involvement in the decision making process, and shows how making strategies for risk communication is a key for a successful process. The study is supported by case study examples from Norway and Italy. In the Italian case study, three different risk mitigation

  18. A web-based tool for ranking landslide mitigation measures

    NASA Astrophysics Data System (ADS)

    Lacasse, S.; Vaciago, G.; Choi, Y. J.; Kalsnes, B.

    2012-04-01

    As part of the research done in the European project SafeLand "Living with landslide risk in Europe: Assessment, effects of global change, and risk management strategies", a compendium of structural and non-structural mitigation measures for different landslide types in Europe was prepared, and the measures were assembled into a web-based "toolbox". Emphasis was placed on providing a rational and flexible framework applicable to existing and future mitigation measures. The purpose of web-based toolbox is to assist decision-making and to guide the user in the choice of the most appropriate mitigation measures. The mitigation measures were classified into three categories, describing whether the mitigation measures addressed the landslide hazard, the vulnerability or the elements at risk themselves. The measures considered include structural measures reducing hazard and non-structural mitigation measures, reducing either the hazard or the consequences (or vulnerability and exposure of elements at risk). The structural measures include surface protection and control of surface erosion; measures modifying the slope geometry and/or mass distribution; measures modifying surface water regime - surface drainage; measures mo¬difying groundwater regime - deep drainage; measured modifying the mechanical charac¬teristics of unstable mass; transfer of loads to more competent strata; retaining structures (to modify slope geometry and/or to transfer stress to compe¬tent layer); deviating the path of landslide debris; dissipating the energy of debris flows; and arresting and containing landslide debris or rock fall. The non-structural mitigation measures, reducing either the hazard or the consequences: early warning systems; restricting or discouraging construction activities; increasing resistance or coping capacity of elements at risk; relocation of elements at risk; sharing of risk through insurance. The measures are described in the toolbox with fact sheets providing a

  19. A review on the generation, determination and mitigation of urban heat island.

    PubMed

    Memon, Rizwan Ahmed; Leung, Dennis Y C; Chunho, Liu

    2008-01-01

    Urban Heat Island (UHI) is considered as one of the major problems in the 21st century posed to human beings as a result of urbanization and industrialization of human civilization. The large amount of heat generated from urban structures, as they consume and re-radiate solar radiations, and from the anthropogenic heat sources are the main causes of UHI. The two heat sources increase the temperatures of an urban area as compared to its surroundings, which is known as Urban Heat Island Intensity (UHII). The problem is even worse in cities or metropolises with large population and extensive economic activities. The estimated three billion people living in the urban areas in the world are directly exposed to the problem, which will be increased significantly in the near future. Due to the severity of the problem, vast research effort has been dedicated and a wide range of literature is available for the subject. The literature available in this area includes the latest research approaches, concepts, methodologies, latest investigation tools and mitigation measures. This study was carried out to review and summarize this research area through an investigation of the most important feature of UHI. It was concluded that the heat re-radiated by the urban structures plays the most important role which should be investigated in details to study urban heating especially the UHI. It was also concluded that the future research should be focused on design and planning parameters for reducing the effects of urban heat island and ultimately living in a better environment. PMID:18572534

  20. 13 CFR 123.21 - What is a mitigation measure?

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false What is a mitigation measure? 123.21 Section 123.21 Business Credit and Assistance SMALL BUSINESS ADMINISTRATION DISASTER LOAN PROGRAM... a disaster occurs (pre-disaster) to protect against future disaster related damage. Examples...

  1. GHG emission mitigation measures and technologies in the Czech Republic

    SciTech Connect

    Tichy, M.

    1996-12-31

    The paper presents a short overview of main results in two fields: projection of GHG emission from energy sector in the Czech Republic and assessment of technologies and options for GHG mitigation. The last part presents an overview of measures that were prepared for potential inclusion to the Czech Climate Change Action Plan.

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

    NASA Astrophysics Data System (ADS)

    Lee, S.; Ryu, Y.

    2014-12-01

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

  3. Priority mitigation measures in non-energy sector in Kazakstan

    SciTech Connect

    Mizina, S.V.; Pilifosova, O.V.; Gossen, E.F.

    1996-12-31

    Fulfilling the Commitments on UN FCCC through the U.S. Country Studies Program, Kazakstan has developed the national GHG Inventory, vulnerability and adaptation assessment and estimated the possibility of mitigation measures in certain sectors. Next step is developing National Climate Change Action Plan. That process includes such major steps as setting priorities in mitigation measures and technologies, their comprehensive evaluation, preparation implementation strategies, developing the procedure of incorporation of the National Action Plan into other development plans and programs. This paper presents programs and measures that can reduce GHG emissions in non-energy sector. Measures in land-use change and forestry, agriculture and coal mining are considered. Current situation in non-energy sector of Kazakstan is discussed. The amount of GHG emissions reduction and cost analysis presented in this paper was developed with the use of IPCC recommendations.

  4. The economics of mitigation and remediation measures - preliminary results

    NASA Astrophysics Data System (ADS)

    Wiedemann, Carsten; Flegel, Sven Kevin; Vörsmann, Peter; Gelhaus, Johannes; Moeckel, Marek; Braun, Vitali; Kebschull, Christopher; Metz, Manuel

    2012-07-01

    Today there exists a high spatial density of orbital debris objects at about 800 km altitude. The control of the debris population in this region is important for the long-term evolution of the debris environment. The future debris population is investigated by simulations using the software tool LUCA (Long-Term Orbit Utilization Collision Analysis). It is likely that in the future there will occur more catastrophic collisions. Debris objects generated during such events may again trigger further catastrophic collisions. Current simulations have revealed that the number of debris objects will increase in the future. In a long-term perspective, catastrophic collisions may become the dominating mechanism in generating orbital debris. In this study it is investigated, when the situation will become unstable. To prevent this instability it is necessary to implement mitigation and maybe even remediation measures. It is investigated how these measures affect the future debris environment. It is simulated if the growth of the number of debris objects can be interrupted and how much this may cost. Different mitigation scenarios are considered. Furthermore also one remediation measure, the active removal of high-risk objects, is simulated. Cost drivers for the different measures are identified. It is investigated how selected measures are associated with costs. The goal is to find out which economic benefits may result from mitigation or remediation. First results of a cost benefit analyses are presented.

  5. Heat-Flux-Measuring Facility

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Weikle, Donald H.

    1990-01-01

    Apparatus simulates conditions in turbine engines. Automated facility generates and measures transient and steady-state heat fluxes at flux densities from 0.3 to 6 MW/m(Sup2) and temperatures from 100 to 1,200 K. Positioning arm holds heat-flux gauge at focal point of arc lamp. Arm previously chilled gauge in liquid nitrogen in Dewar flask. Cooling water flows through lamp to heat exchanger. Used to develop heat-flux gauges for turbine blades and to test materials for durability under rapidly changing temperatures.

  6. Simulation for heat flux mitigation by gas puffing in KSTAR

    NASA Astrophysics Data System (ADS)

    Shim, Seung Bo; Kotov, Vladislav; Hong, Suk-Ho; Detlev, Reiter; Kim, Jin Yong; Na, Yong Su; Lee, Hae June

    2013-10-01

    Control of heat flux is very important to achieve high performance long pulse operation in tokamaks. There are so many efforts to reduce the heat flux like change of divertor structure, snowflake divertor, and RMP, etc. Detachment by gas puffing is used for long time to reduce the heat flux. In this paper edge plasma scenarios of KSTAR are analyzed numerically by well-known B2-Eirene code package(SOLPS4.3). High performance discharges with heating power ~ 8 MW and core flux ~ 1021 s-1 is used. Gas puffed on the outer mid-plane(OMP), both divertors is likely to stay attached. So, gas puffed on the outer target, one is near the private flux region(PFR) and the other is near the scrape-off-layer(SOL). When gas puffed near the SOL is still attached, and it is worse than gas puff from OMP because it is too close to cryo-pump. The case near the PFR shows high recycling region easily compared with OMP case. When one forth gas puffed on the PFR, results are similar with OMP case. But it is still not good for detachment operation. Detachment operation window is too small for the gas puffing on the PFR. This work was supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MEST)(No. 2012-0000579).

  7. PREFERENCE EVALUATION AND DECISION SUPPORT FOR MULTIPLE UTILITIES OF HEAT MITIGATION PROJECTS

    NASA Astrophysics Data System (ADS)

    Nakagawa, Hideharu; Nakatani, Jun; Kurisu, Kiyo; Hanaki, Keisuke

    Heat mitigation projects, such as green roof, waterfront, mist spraying and water-retentive pavement, are mainly intended to decrease outdoor temperature, while some of them have multiple utilities including increase of species, mitigation of flood, improvement of spatial design and environmental enlightenment in addition to decrease in outdoor temperature. This paper proposes and demonstrates a decision support method for alternative design based on prioritization and preference evaluation for multiple utilities of heat mitigation projects. First, applying analytic hierarchy process (AHP), the priority order of project implementation was decided based on subjective evaluation of multi-stakeholders such as benefit recipients, experts and project implementers on multiple utilities of the projects. Then, the preference structure of office workers as benefit recipients of projects was identified using conjoint analysis, each utility was evaluated in monetary value, and discussed which aspects should be emphasized on detailed project planning.

  8. Cooler paving materials for heat-island mitigation

    SciTech Connect

    Pomerantz, M.; Akbari, H.

    1998-07-01

    Many cities suffer summer daytime temperatures greater than their suburban or rural surroundings. One of the causes of this heat island phenomenon is the absorption of sunlight by dark pavements. In warm climates, the urban heating damages the environment by adding to air-conditioning demand and creating smog. If urban roads, driveways and walkways were paved with light colored, and consequently cooler, materials these penalties would be diminished. However, lighter materials may cost more than the usual asphalt materials, In this report, the dollar value of potential air conditioning and smog savings from lighter pavements is estimated, and compared to the extra cost of such roads. The extra cost is minimized if the lighter-colored coating is applied as a thin layer when normal maintenance is performed. The authors find that, in Los Angeles, increasing the albedo from 0.1 to 0.35, could produce an air-conditioning saving of $0.012/m{sub 2}-yr. and smog savings of about $0.06/m{sub 2}-yr. The present value of these savings, for the 5 year lifetime of the resurfacing, is about 5 times the annual saving, or about $0.36/m{sub 2}. (The particular climate and smog problem clearly influence this result.) Thus one could purchase a cooler material whose extra cost is this amount, with no net expense. If roads are cooler they may also last longer and thus save money.

  9. Mitigation potential of horizontal ground coupled heat pumps for current and future climatic conditions: UK environmental modelling and monitoring studies

    NASA Astrophysics Data System (ADS)

    García González, Raquel; Verhoef, Anne; Vidale, Pier Luigi; Gan, Guohui; Wu, Yupeng; Hughes, Andrew; Mansour, Majdi; Blyth, Eleanor; Finch, Jon; Main, Bruce

    2010-05-01

    model predictions of soil moisture content and soil temperature with measurements at different GCHP locations over the UK. The combined effect of environment dynamics and horizontal GCHP technical properties on long-term GCHP performance will be assessed using a detailed land surface model (JULES: Joint UK Land Environment Simulator, Meteorological Office, UK) with additional equations embedded describing the interaction between GCHP heat exchangers and the surrounding soil. However, a number of key soil physical processes are currently not incorporated in JULES, such as groundwater flow, which, especially in lowland areas, can have an important effect on the heat flow between soil and HE. Furthermore, the interaction between HE and soil may also cause soil vapour and moisture fluxes. These will affect soil thermal conductivity and hence heat flow between the HE and the surrounding soil, which will in turn influence system performance. The project will address these issues. We propose to drive an improved version of JULES (with equations to simulate GCHP exchange embedded), with long-term gridded (1 km) atmospheric, soil and vegetation data (reflecting current and future environmental conditions) to reliably assess the mitigation potential of GCHPs over the entire domain of the UK, where uptake of GCHPs has been low traditionally. In this way we can identify areas that are most suitable for the installation of GCHPs. Only then recommendations can be made to local and regional governments, for example, on how to improve the mitigation potential in less suitable areas by adjusting GCHP configurations or design.

  10. The role of one large greenspace in mitigating London's nocturnal urban heat island.

    PubMed

    Doick, Kieron J; Peace, Andrew; Hutchings, Tony R

    2014-09-15

    The term urban heat island (UHI) describes a phenomenon where cities are on average warmer than the surrounding rural area. Trees and greenspaces are recognised for their strong potential to regulate urban air temperatures and combat the UHI. Empirical data is required in the UK to inform predictions on cooling by urban greenspaces and guide planning to maximise cooling of urban populations. We describe a 5-month study to measure the temperature profile of one of central London's large greenspaces and also in an adjacent street to determine the extent to which the greenspace reduced night-time UHI intensity. Statistical modelling displayed an exponential decay in the extent of cooling with increased distance from the greenspace. The extent of cooling ranged from an estimated 20 m on some nights to 440 m on other nights. The mean temperature reduction over these distances was 1.1 °C in the summer months, with a maximum of 4 °C cooling observed on some nights. Results suggest that calculation of London's UHI using Met Stations close to urban greenspace can underestimate 'urban' heat island intensity due to the cooling effect of the greenspace and values could be in the region of 45% higher. Our results lend support to claims that urban greenspace is an important component of UHI mitigation strategies. Lack of certainty over the variables that govern the extent of the greenspace cooling influence indicates that the multifaceted roles of trees and greenspaces in the UK's urban environment merit further consideration. PMID:24995636

  11. Latent heat sink in soil heat flux measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The surface energy balance includes a term for soil heat flux. Soil heat flux is difficult to measure because it includes conduction and convection heat transfer processes. Accurate representation of soil heat flux is an important consideration in many modeling and measurement applications. Yet, the...

  12. Assessment of GHG mitigation technology measures in Ukraine

    SciTech Connect

    Raptsoun, N.; Parasiouk, N.

    1996-12-31

    In June 1992 the representatives of 176 countries including Ukraine met in Rio de Janeiro at the UN Conference to coordinate its efforts in protecting and guarding the environment. Signature of the UN Framework Convention on Climate Change by around 150 countries indicates that climate change is potentially a major threat to the world`s environment and economic development. The project {open_quotes}Country Study on Climate Change in Ukraine{close_quotes} coordinated by the Agency for Rational Energy Use and Ecology (ARENIA-ECO) and supported by the US Country Studies Program Support for Climate Change Studies. The aim of the project is to make the information related to climate change in Ukraine available for the world community by using the potential of Ukrainian research institutes for further concerted actions to solve the problem of climate change on the global scale. The project consists of four elements: (1) the development of the GHG Inventory in Ukraine; (2) assessments of ecosystems-vulnerability to climate change and adaptation options; and (3) mitigation options analysis; (4) public education and outreach activities. This paper contains the main results of the third element for the energy and non-energy sectors. Main tasks of the third element were: (1) to select, test and describe or develop the methodology for mitigation options assessment; (2) to analyze the main sources of GHG emissions in Ukraine; (3) to give the macro economic analysis of Ukrainian development and the development of main economical sectors industry, energy, transport, residential, forestry and agriculture; (4) to forecast GHG emissions for different scenarios of the economic development; and (5) to analyze the main measures to mitigate climate change.

  13. Validation of a Fast-Response Urban Micrometeorological Model to Assess the Performance of Urban Heat Island Mitigation Strategies

    NASA Astrophysics Data System (ADS)

    Nadeau, D.; Girard, P.; Overby, M.; Pardyjak, E.; Stoll, R., II; Willemsen, P.; Bailey, B.; Parlange, M. B.

    2015-12-01

    Urban heat islands (UHI) are a real threat in many cities worldwide and mitigation measures have become a central component of urban planning strategies. Even within a city, causes of UHI vary from one neighborhood to another, mostly due the spatial variability in surface thermal properties, building geometry, anthropogenic heat flux releases and vegetation cover. As a result, the performance of UHI mitigation measures also varies in space. Hence, there is a need to develop a tool to quantify the efficiency of UHI mitigation measures at the neighborhood scale. The objective of this ongoing study is to validate the fast-response micrometeorological model QUIC EnvSim (QES). This model can provide all information required for UHI studies with a fine spatial resolution (up to 0.5m) and short computation time. QES combines QUIC, a CFD-based wind solver and dispersion model, and EnvSim, composed of a radiation model, a land-surface model and a turbulent transport model. Here, high-resolution (1 m) simulations are run over a subset of the École Polytechnique Fédérale de Lausanne (EPFL) campus including complex buildings, various surfaces properties and vegetation. For nearly five months in 2006-07, a dense network of meteorological observations (92 weather stations over 0.1 km2) was deployed over the campus and these unique data are used here as a validation dataset. We present validation results for different test cases (e.g., sunny vs cloudy days, different incoming wind speeds and directions) and explore the effect of a few UHI mitigation strategies on the spatial distribution of near-surface air temperatures. Preliminary results suggest that QES may be a valuable tool in decision-making regarding adaptation of urban planning to UHI.

  14. Kinematic analysis for the implementation of landslide mitigation measures

    NASA Astrophysics Data System (ADS)

    Delmonaco, Giuseppe; Margottini, Claudio; Spizzichino, Daniele

    2010-05-01

    The present work is finalised at the implementation of a landslide risk mitigation master plan of the ancient citadel of Machu Picchu. After the warning launched in March 2001, by the scientific community on potential collapse of the citadel from a near-disastrous landslide event different studies have been promoted to reconstruct landslide activity and suggest landslide risk mitigation measures for the protection and conservation of Machu Picchu cultural heritage. A site-scale analysis has been implemented following the application and integration of geomechanical classifications, ambient noise measurements and structural and kinematical analysis. The geology of the area is characterized by granitoid bodies that had been emplaced in the axial zones of the main rift system that are now exposed at the highest altitudes, together with country rocks (Precambrian and Lower Paleozoic metamorphics) originally constituting the rift ‘roots'. The bedrock of the Inca citadel of Machu Picchu is mainly composed by granite and subordinately granodiorite. This is mainly located in the lower part of the slopes. Superficially, the granite is jointed in blocks with variable dimensions, promoted by local structural setting. Single blocks vary from 10-1 to about 200 m3. Soil cover, widely outcropping in the area, is mainly composed by individual blocks and subordinately by coarse materials originated by chemical and physical weathering of minerals. Regional tectonic uplift and structural setting rule the general morphological features of the area and as a consequence, landslide type and evolution. Rock falls, rock slides, debris flows and debris slides are the main landslide typologies affecting the citadel slopes. In the last mission in May 2009, elastic and deformation rock parameters have been collected using a passive seismic innovative technique based on natural microtremor measurements and geostructural scan lines elaboration. A landslide zoning of the citadel has been

  15. Atmospheric Effects on InSAR Measurements and Their Mitigation

    PubMed Central

    Ding, Xiao-li; Li, Zhi-wei; Zhu, Jian-jun; Feng, Guang-cai; Long, Jiang-ping

    2008-01-01

    Interferometric Synthetic Aperture Radar (InSAR) is a powerful technology for observing the Earth surface, especially for mapping the Earth's topography and deformations. InSAR measurements are however often significantly affected by the atmosphere as the radar signals propagate through the atmosphere whose state varies both in space and in time. Great efforts have been made in recent years to better understand the properties of the atmospheric effects and to develop methods for mitigating the effects. This paper provides a systematic review of the work carried out in this area. The basic principles of atmospheric effects on repeat-pass InSAR are first introduced. The studies on the properties of the atmospheric effects, including the magnitudes of the effects determined in the various parts of the world, the spectra of the atmospheric effects, the isotropic properties and the statistical distributions of the effects, are then discussed. The various methods developed for mitigating the atmospheric effects are then reviewed, including the methods that are based on PSInSAR processing, the methods that are based on interferogram modeling, and those that are based on external data such as GPS observations, ground meteorological data, and satellite data including those from the MODIS and MERIS. Two examples that use MODIS and MERIS data respectively to calibrate atmospheric effects on InSAR are also given.

  16. Self-Regulated Plasma Heat Flux Mitigation Due to Liquid Sn Vapor Shielding.

    PubMed

    van Eden, G G; Morgan, T W; Aussems, D U B; van den Berg, M A; Bystrov, K; van de Sanden, M C M

    2016-04-01

    A steady-state high-flux H or He plasma beam was balanced against the pressure of a Sn vapor cloud for the first time, resulting in a self-regulated heat flux intensity near the liquid surface. A temperature response of the liquid surface characterized by a decoupling from the received heating power and significant cooling of the plasma in the neutral Sn cloud were observed. The plasma heat flux impinging on the target was found to be mitigated, as heat was partially dissipated by volumetric processes in the vapor cloud rather than wholly by surface effects. These results motivate further exploration of liquid metal solutions to the critical challenge of heat and particle flux handling in fusion power plants. PMID:27081983

  17. Self-Regulated Plasma Heat Flux Mitigation Due to Liquid Sn Vapor Shielding

    NASA Astrophysics Data System (ADS)

    van Eden, G. G.; Morgan, T. W.; Aussems, D. U. B.; van den Berg, M. A.; Bystrov, K.; van de Sanden, M. C. M.

    2016-04-01

    A steady-state high-flux H or He plasma beam was balanced against the pressure of a Sn vapor cloud for the first time, resulting in a self-regulated heat flux intensity near the liquid surface. A temperature response of the liquid surface characterized by a decoupling from the received heating power and significant cooling of the plasma in the neutral Sn cloud were observed. The plasma heat flux impinging on the target was found to be mitigated, as heat was partially dissipated by volumetric processes in the vapor cloud rather than wholly by surface effects. These results motivate further exploration of liquid metal solutions to the critical challenge of heat and particle flux handling in fusion power plants.

  18. Effects of road mortality and mitigation measures on amphibian populations.

    PubMed

    Beebee, Trevor J C

    2013-08-01

    Road mortality is a widely recognized but rarely quantified threat to the viability of amphibian populations. The global extent of the problem is substantial and factors affecting the number of animals killed on highways include life-history traits and landscape features. Secondary effects include genetic isolation due to roads acting as barriers to migration. Long-term effects of roads on population dynamics are often severe and mitigation methods include volunteer rescues and under-road tunnels. Despite the development of methods that reduce road kill in specific locations, especially under-road tunnels and culverts, there is scant evidence that such measures will protect populations over the long term. There also seems little likelihood that funding will be forthcoming to ameliorate the problem at the scale necessary to prevent further population declines. PMID:23647090

  19. Urban heat mitigation by roof surface materials during the East Asian summer monsoon

    NASA Astrophysics Data System (ADS)

    Lee, Seungjoon; Ryu, Youngryel; Jiang, Chongya

    2015-12-01

    Roof surface materials, such as green and white roofs, have attracted attention in their role in urban heat mitigation, and various studies have assessed the cooling performance of roof surface materials during hot and sunny summer seasons. However, summers in the East Asian monsoon climate region are characterized by significant fluctuations in weather events, such as dry periods, heatwaves, and rainy and cloudy days. This study investigated the efficacy of different roof surface materials for heat mitigation, considering the temperatures both at and beneath the surface of the roof covering materials during a summer monsoon in Seoul, Korea. We performed continuous observations of temperature at and beneath the surface of the roof covering materials, and manual observation of albedo and the normalized difference vegetation index for a white roof, two green roofs (grass (Poa pratensis) and sedum (Sedum sarmentosum)), and a reference surface. Overall, the surface temperature of the white roof was significantly lower than that of the grass and sedum roofs (1.1 °C and 1.3 °C), whereas the temperature beneath the surface of the white roof did not differ significantly from that of the grass and sedum roofs during the summer. The degree of cloudiness significantly modified the surface temperature of the white roof compared with that of the grass and sedum roofs, which depended on plant metabolisms. It was difficult for the grass to maintain its cooling ability without adequate watering management. After considering the cooling performance and maintenance efforts for different environmental conditions, we concluded that white roof performed better in urban heat mitigation than grass and sedum during the East Asian summer monsoon. Our findings will be useful in urban heat mitigation in the region.

  20. Plasma facing materials performance under ITER-relevant mitigated disruption photonic heat loads

    NASA Astrophysics Data System (ADS)

    Klimov, N. S.; Putrik, A. B.; Linke, J.; Pitts, R. A.; Zhitlukhin, A. M.; Kuprianov, I. B.; Spitsyn, A. V.; Ogorodnikova, O. V.; Podkovyrov, V. L.; Muzichenko, A. D.; Ivanov, B. V.; Sergeecheva, Ya. V.; Lesina, I. G.; Kovalenko, D. V.; Barsuk, V. A.; Danilina, N. A.; Bazylev, B. N.; Giniyatulin, R. N.

    2015-08-01

    PFMs (Plasma-facing materials: ITER grade stainless steel, beryllium, and ferritic-martensitic steels) as well as deposited erosion products of PFCs (Be-like, tungsten, and carbon based) were tested in QSPA under photonic heat loads relevant to those expected from photon radiation during disruptions mitigated by massive gas injection in ITER. Repeated pulses slightly above the melting threshold on the bulk materials eventually lead to a regular, "corrugated" surface, with hills and valleys spaced by 0.2-2 mm. The results indicate that hill growth (growth rate of ∼1 μm per pulse) and sample thinning in the valleys is a result of melt-layer redistribution. The measurements on the 316L(N)-IG indicate that the amount of tritium absorbed by the sample from the gas phase significantly increases with pulse number as well as the modified layer thickness. Repeated pulses significantly below the melting threshold on the deposited erosion products lead to a decrease of hydrogen isotopes trapped during the deposition of the eroded material.

  1. Uncertainty of Mitigation Measures to Floods in Jeddah, Saudi Arabia

    NASA Astrophysics Data System (ADS)

    Al Saud, M.

    2011-12-01

    As an aspect of the changing climatic conditions and anthropogenic impact; however, floods and torrents have been recently existed in Jeddah, the coastal Saudi city along the Red Sea. Distributed over 28 surface water basins, totaling an area of more than 2500km2, floods cover more than 15% of the area. This is well pronounced in 2009 and 2011, and it was attributed mainly to the torrential rainfall peaks the area witnesses lately. In addition, there is a chaotic urban distribution from the coastal zone to the adjacent mountain chains to the east, where torrential water runs towards the coast. A detailed assessment has been obtained using advanced space tools (e.g. high-resolution satellite images), and the application was carried out on several aspects of these images and at different dates. This was accomplished in combination the applications of geo-spatial systems to induce the mechanism of water flow regime and to identify the major reasons behind the high risk magnitude. Consequently, the geomorphologic and hydrologic parameters for flood occurrence were recognized. In the light of this catastrophic status; however, mitigation measures are rare enough to protect the area under risk. Recently, and after the 2009 and the recurrent 2011 disasters, which were resulted from floods, some mitigation measures have been undertaken and others were proposed. However, there is still uncertainty for an integrated flood control system. This can be viewed from the unsuitability of the selected sites and erroneous applications for flood controls. Besides, there is a lack to: 1) a giant channeling system for the risk area, 2) check dams, 3) ponds for water collection, 4) sediments-fixing controls, 5) traced watercourses. This is in addition to absence of proper legislation to prevent chaotic urban activities along valleys' pathways.

  2. The Urban Tree as a Tool to Mitigate the Urban Heat Island in Mexico City: A Simple Phenomenological Model.

    PubMed

    Ballinas, Mónica; Barradas, Víctor L

    2016-01-01

    The urban heat island (UHI) is mainly a nocturnal phenomenon, but it also appears during the day in Mexico City. The UHI may affect human thermal comfort, which can influence human productivity and morbidity in the spring/summer period. A simple phenomenological model based on the energy balance was developed to generate theoretical support of UHI mitigation in Mexico City focused on the latent heat flux change by increasing tree coverage to reduce sensible heat flux and air temperature. Half-hourly data of the urban energy balance components were generated in a typical residential/commercial neighborhood of Mexico City and then parameterized using easily measured variables (air temperature, humidity, pressure, and visibility). Canopy conductance was estimated every hour in four tree species, and transpiration was estimated using sap flow technique and parameterized by the envelope function method. Averaged values of net radiation, energy storage, and sensible and latent heat flux were around 449, 224, 153, and 72 W m, respectively. Daily tree transpiration ranged from 3.64 to 4.35 Ld. To reduce air temperature by 1°C in the studied area, 63 large would be required per hectare, whereas to reduce the air temperature by 2°C only 24 large trees would be required. This study suggests increasing tree canopy cover in the city cannot mitigate UHI adequately but requires choosing the most appropriate tree species to solve this problem. It is imperative to include these types of studies in tree selection and urban development planning to adequately mitigate UHI. PMID:26828171

  3. Simulation of tokamak SOL and divertor region including heat flux mitigation by gas puffing

    SciTech Connect

    Park, Jin Woo; Na, Y. S.; Hong, S. H.; Ahn, J.W.; Kim, D. K.; Han, Hyunsun; Shim, Seong Bo; Lee, Hae June

    2012-01-01

    Two-dimensional (2D), scrape-off layer (SOL)-divertor transport simulations are performed using the integrated plasma-neutral-impurity code KTRAN developed at Seoul National University. Firstly, the code is applied to reproduce a National Spherical Torus eXperiment (NSTX) discharge by using the prescribed transport coefficients and the boundary conditions obtained from the experiment. The plasma density, the heat flux on the divertor plate, and the D (alpha) emission rate profiles from the numerical simulation are found to follow experimental trends qualitatively. Secondly, predictive simulations are carried out for the baseline operation mode in Korea Superconducting Tokamak Advanced Research (KSTAR) to predict the heat flux on the divertor target plates. The stationary peak heat flux in the KSTAR baseline operation mode is expected to be 6.5 MW/m(2) in the case of an orthogonal divertor. To study the mitigation of the heat flux, we investigated the puffing effects of deuterium and argon gases. The puffing position is assumed to be in front of the strike point at the outer lower divertor plate. In the simulations, mitigation of the peak heat flux at the divertor target plates is found to occur when the gas puffing rate exceeds certain values, similar to 1.0 x 10(20) /s and similar to 5.0 x 10(18) /s for deuterium and argon, respectively. Multi-charged impurity transport is also investigated for both NSTX and KSTAR SOL and divertor regions.

  4. Study on mitigation of pulsed heat load for ITER cryogenic system

    NASA Astrophysics Data System (ADS)

    Peng, N.; Xiong, L. Y.; Jiang, Y. C.; Tang, J. C.; Liu, L. Q.

    2015-03-01

    One of the key requirements for ITER cryogenic system is the mitigation of the pulsed heat load deposited in the magnet system due to magnetic field variation and pulsed DT neutron production. As one of the control strategies, bypass valves of Toroidal Field (TF) case helium loop would be adjusted to mitigate the pulsed heat load to the LHe plant. A quasi-3D time-dependent thermal-hydraulic analysis of the TF winding packs and TF case has been performed to study the behaviors of TF magnets during the reference plasma scenario with the pulses of 400 s burn and repetition time of 1800 s. The model is based on a 1D helium flow and quasi-3D solid heat conduction model. The whole TF magnet is simulated taking into account thermal conduction between winding pack and case which are cooled separately. The heat loads are given as input information, which include AC losses in the conductor, eddy current losses in the structure, thermal radiation, thermal conduction and nuclear heating. The simulation results indicate that the temperature variation of TF magnet stays within the allowable range when the smooth control strategy is active.

  5. Overview of mitigation policies and measures in the forestry sector

    SciTech Connect

    Sathaye, J.

    1996-12-31

    In this paper the author addresses questions on how the forestry sector can make a contribution to the general problem of greenhouse gases in the environment. Primarily this is in the form of carbon conservation and sequestering. There is a potential land area for conservation and sequestration estimated to be 700 Mha. The total carbon that could be sequestered and conserved globally by 2050 on this land is 60 - 87 GtC. Slowing deforestation, assisting regeneration, forestation and agroforestry are the primary mitigation measures for carbon conservation and sequestration. For long term success, enforcement to halt deforestation has to be accompained by economic and/or other benefits to the deforesters that equal or exceed their current remuneration. Making plantations a significant fuel for utility electricity generation will require higher biomass yields and thermal efficiency matching that of conventional plants. Significant reduction of global carbon emissions requires national governments to institute measures that provide local, national, economic and other benefits while conserving and sequestering carbon.

  6. Mitigation of heat stress-related complications by a yeast fermentate product.

    PubMed

    Giblot Ducray, Henri Alexandre; Globa, Ludmila; Pustovyy, Oleg; Reeves, Stuart; Robinson, Larry; Vodyanoy, Vitaly; Sorokulova, Iryna

    2016-08-01

    Heat stress results in a multitude of biological and physiological responses which can become lethal if not properly managed. It has been shown that heat stress causes significant adverse effects in both human and animals. Different approaches have been proposed to mitigate the adverse effects caused by heat stress, among which are special diet and probiotics. We characterized the effect of the yeast fermentate EpiCor (EH) on the prevention of heat stress-related complications in rats. We found that increasing the body temperature of animals from 37.1±0.2 to 40.6±0.2°C by exposure to heat (45°C for 25min) resulted in significant morphological changes in the intestine. Villi height and total mucosal thickness decreased in heat-stressed rats pre-treated with PBS in comparison with control animals not exposed to the heat. Oral treatment of rats with EH before heat stress prevented the traumatic effects of heat on the intestine. Changes in intestinal morphology of heat-stressed rats, pre-treated with PBS resulted in significant elevation of lipopolysaccharides (LPS) level in the serum of these animals. Pre-treatment with EH was effective in the prevention of LPS release into the bloodstream of heat-stressed rats. Our study revealed that elevation of body temperature also resulted in a significant increase of the concentration of vesicles released by erythrocytes in rats, pre-treated with PBS. This is an indication of a pathological impact of heat on the erythrocyte structure. Treatment of rats with EH completely protected their erythrocytes from this heat-induced pathology. Finally, exposure to heat stress conditions resulted in a significant increase of white blood cells in rats. In the group of animals pre-treated with EH before heat stress, the white blood cell count remained the same as in non-heated controls. These results showed the protective effect of the EH product in the prevention of complications, caused by heat stress. PMID:27503713

  7. Human Factors Research for Space Exploration: Measurement, Modeling, and Mitigation

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary K.; Allen, Christopher S.; Barshi, Immanuel; Billman, Dorrit; Holden, Kritina L.

    2010-01-01

    As part of NASA's Human Research Program, the Space Human Factors Engineering Project serves as the bridge between Human Factors research and Human Spaceflight applications. Our goal is to be responsive to the operational community while addressing issues at a sufficient level of abstraction to ensure that our tools and solutions generalize beyond the point design. In this panel, representatives from four of our research domains will discuss the challenges they face in solving current problems while also enabling future capabilities. Historically, engineering-dominated organizations have tended to view good Human Factors (HF) as a desire rather than a requirement in system design and development. Our field has made significant gains in the past decade, however; the Department of Defense, for example, now recognizes Human-System Integration (HSI), of which HF is a component, as an integral part of their divisions hardware acquisition processes. And our own agency was far more accepting of HF/HSI requirements during the most recent vehicle systems definition than in any prior cycle. Nonetheless, HF subject matter experts at NASA often find themselves in catch up mode... coping with legacy systems (hardware and software) and procedures that were designed with little regard for the human element, and too often with an attitude of we can deal with any operator issues during training. Our challenge, then, is to segregate the true knowledge gaps in Space Human Factors from the prior failures to incorporate best (or even good) HF design principles. Further, we strive to extract the overarching core HF issues from the point-design-specific concerns that capture the operators (and managers) attention. Generally, our approach embraces a 3M approach to Human Factors: Measurement, Modeling, and Mitigation. Our first step is to measure human performance, to move from subjective anecdotes to objective, quantified data. Next we model the phenomenon, using appropriate methods in

  8. Mitigation of biofouling using electromagnetic fields in tubular heat exchangers-condensers cooled by seawater.

    PubMed

    Trueba, Alfredo; García, Sergio; Otero, Félix M

    2014-01-01

    Electromagnetic field (EMF) treatment is presented as an alternative physical treatment for the mitigation of biofouling adhered to the tubes of a heat exchanger-condenser cooled by seawater. During an experimental phase, a fouling biofilm was allowed to grow until experimental variables indicated that its growth had stabilised. Subsequently, EMF treatment was applied to seawater to eliminate the biofilm and to maintain the achieved cleanliness. The results showed that EMFs precipitated ions dissolved in the seawater. As a consequence of the application of EMFs, erosion altered the intermolecular bonding of extracellular polymers, causing the destruction of the biofilm matrix and its detachment from the inner surface of the heat exchanger-condenser tubes. This detachment led to the partial removal of a mature biofilm and a partial recovery of the efficiency lost in the heat transfer process by using a physical treatment that is harmless to the marine environment. PMID:24266611

  9. Airflow measurement techniques applied to radon mitigation problems

    SciTech Connect

    Harrje, D.T.; Gadsby, K.J.

    1989-01-01

    During the past decade a multitude of diagnostic procedures associated with the evaluation of air infiltration and air leakage sites have been developed. The spirit of international cooperation and exchange of ideas within the AIC-AIVC conferences has greatly facilitated the adoption and use of these measurement techniques in the countries participating in Annex V. But wide application of such diagnostic methods are not limited to air infiltration alone. The subject of this paper concerns the ways to evaluate and improve radon reduction in buildings using diagnostic methods directly related to developments familiar to the AIVC. Radon problems are certainly not unique to the United States, and the methods described here have to a degree been applied by researchers of other countries faced with similar problems. The radon problem involves more than a harmful pollutant of the living spaces of our buildings -- it also involves energy to operate radon removal equipment and the loss of interior conditioned air as a direct result. The techniques used for air infiltration evaluation will be shown to be very useful in dealing with the radon mitigation challenge. 10 refs., 7 figs., 1 tab.

  10. The impact of green areas in mitigation of urban heat island

    NASA Astrophysics Data System (ADS)

    Zaninovic, Ksenija

    2016-04-01

    In the framework of the project REPUBLICMED (REtroffiting PUBLic spaces in Intelligent MEDiterranean Cities) co-financed by the European Union, the changes in urban structure have to be proposed in order to mitigate the urban heat island in Zadar, Croatia. The intention is to compare thermal perception for selected locations in Zadar in the present situation and after proposed changes in different parts of the year. For that purpose, four days in different seasons were selected. For winter and summer, the days with extreme minimum and maximum temperatures were selected, whilst for spring and autumn the days in the middle of seasons (April and October) with mean temperatures similar to the corresponding mean seasonal temperatures were selected. All selected days were mainly clear or with small cloudiness resulting with maximum solar radiation. The thermal perception was calculated by means of biometeorological index based on energy equilibrium between human body and environment - physiologically equivalent temperature (PET). In the first analysis, daily courses of biometeorological index for selected situations based on hourly data were compared. During warmest parts of the day in summer the thermal perception differs up to 5°C under the tree shadow, while the differences in other seasons are smaller. The second analysis included the differences in the distribution of frequencies of thermal perception in the warmest part of the day (2 p.m.) throughout the year for selected locations. It is performed using meteorological data measured at the meteorological station Zadar in the 30-year climate period 1981-2010. The results have revealed the reduction in the frequency of sensations of hot and very hot (PET > 35°C or 41°C) under the shadow of the trees during summer, at the rate of up to 25% comparing to the situation before modification (without trees).

  11. Hydraulic analysis of measures for flood mitigation in floodplain

    NASA Astrophysics Data System (ADS)

    Valentova, J.; Valenta, P.; Weyskrabova, L.; Dostal, T.

    2012-04-01

    The question of possible flood control and flood mitigation measures and their effects is still challenging. While the effect of purely technical flood control measures such as dams or levees is sufficiently described by using any of widely spread or more specific models, the effectiveness of close-to-nature ones (river restoration, appropriate land use, landscape structure regeneration, etc.) is not adequately verified and quantified. On that account, the benefits and feasibility of integration of the natural potential of floodplains to absorb and transform flood wave is being discussed. In addition, there are many side benefits of close-to-nature measures which are hard to evaluate and include into decision making processes. This contribution presents a part of the study related to river and floodplain restoration and revitalization measures in catchments and their flood-control effect. In the study the possibilities of using one-dimensional (HEC-RAS) and two-dimensional hydraulic mathematical models (FAST2D, DIFEM2D) of steady and unsteady flow for estimation of transformation effects of a floodplain were compared. The comparison of used models was made with respect to computed results and also to the availability of input data, mathematical stability, processes and accuracy demands and time requirements. The above mentioned methods of hydraulic modelling were applied to three case study localities in the Czech Republic. The parts of river channels and their floodplain differ in terms of morphology, river channel form and training situation and land-use. Case study areas were selected to represent the main types of floodplains within the Czech Republic for their further classification related to flood wave transformation potential. The transformation effect is compared not only for the natural state of the floodplain, but also for various theoretical scenarios in each locality. Keywords Hydraulic modelling, flood control, floodplain, storage capacity, river

  12. Mitigating the Urban Heat Island under Climate Change through Urban Management

    NASA Astrophysics Data System (ADS)

    Zhao, L.; Lee, X.; Oleson, K. W.; Schultz, N. M.; Smith, R. B.

    2015-12-01

    The urban heat island (UHI) represents ubiquitous urban warmth compared to surrounding rural areas. This phenomenon, when compounded with future climate warming, will exacerbate heat stress on urban residents who will comprise 70% of the world's population by 2070. At the same time, urban climate adaptation plans have shown great potential for reducing the impacts of global change. In this study, we assess three mitigation strategies, including reflective roofs, green roofs, and street trees, to ameliorate the warming under climate change through both "online" and "offline" methods. The "online" method compares modeling results from a modified urban roof albedo configuration (ALB-MOD) where the roof albedo is raised to a high reflective value to the modeling results from the default configuration (CTRL), both using the Community Earth System Model (CESM). Three pairs of simulations under current climate forcing and two future scenarios (RCP4.5 and RCP8.5) are conducted. The "offline" method uses a surface temperature attribution solution derived previously for partitioning the UHI intensity to assess the efficacy of the mitigation strategies. The "offline" method supplements the "online" method in assessing green roof and street tree strategies, because the current design of CESM does not have explicit vegetation in the urban canopy configuration. The excellent agreement between the "online" and "offline" results confirms the validity of the offline scheme, supporting that the "offline" method can be used to predict the impacts of various urban adaptation strategies for development planning. Results show that albedo management is the most effective and viable way to mitigate UHIs, whereas although green roof and street trees strategies have evaporative cooling effects, the cooling is compensated by vegetation's lower albedo, showing much less effectiveness on UHI mitigation. Although convection efficiency associated with the surface roughness is an important

  13. Climate benefits of changes in agricultural practices in the context of heat wave mitigation

    NASA Astrophysics Data System (ADS)

    Davin, E.; Seneviratne, S. I.; Ciais, P.; Olioso, A.; Wang, T.

    2014-12-01

    About half of the terrestrial biosphere is under direct human influence through land management (i.e., agricultural areas and managed forests). Changing management practices is therefore a promising avenue for climate change mitigation. The mitigation potential arising from changes in land management practices has been mainly evaluated in terms of carbon storage and GHG emissions [2]. On the other hand, these practices can also influence climate by altering the physical properties of the land surface, but these effects have received less attention so far. Here we show that peak temperatures during heat heaves can be attenuated through cropland albedo management [2]. We first present observational evidence that a substantial summer albedo increase can be obtained by switching from conventional to no-till agriculture. Then, using a regional climate model, we investigate the biogeophysical effect of a full conversion to no-till management over Europe. The cooling effect owing to albedo increase under no-till farming appears to be strongly amplified during warm events. This is due to the low cloud cover during these events, thus leading to a more efficient radiative cooling from albedo change. This implies a strong potential of no-till farming to mitigate heat wave impacts. The reduced evaporation associated with the crop residue cover tends to counteract the albedo-induced cooling, but during hot days the albedo effect remains the dominating factor. For heatwave summer days the local cooling effect gained from no-till practice is of the order of 2 degrees. These findings strongly suggest that the biogeophysical effect of management practices should be considered in the design of climate mitigation policies involving land management. References:[1] Smith, P. et al. (2014): Agriculture, Forestry and Other Land Use (AFOLU). In Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III to the Fifth Assessment Report of the Intergovernmental Panel

  14. Assessment of human thermal comfort and mitigation measures in different urban climatotopes

    NASA Astrophysics Data System (ADS)

    Müller, N.; Kuttler, W.

    2012-04-01

    This study analyses thermal comfort in the model city of Oberhausen as an example for the densely populated metropolitan region Ruhr, Germany. As thermal loads increase due to climate change negative impacts especially for city dwellers will arise. Therefore mitigation strategies should be developed and considered in urban planning today to prevent future thermal stress. The method consists of the combination of in-situ measurements and numerical model simulations. So in a first step the actual thermal situation is determined and then possible mitigation strategies are derived. A measuring network was installed in eight climatotopes for a one year period recording air temperature, relative humidity, wind speed and wind direction. Based on these parameters the human thermal comfort in terms of physiological equivalent temperature (PET) was calculated by RayMan Pro software. Thus the human comfort of different climatotopes was determined. Heat stress in different land uses varies, so excess thermal loads in urban areas could be detected. Based on the measuring results mitigation strategies were developed, such as increasing areas with high evaporation capacity (green areas and water bodies). These strategies were implemented as different plan scenarios in the microscale urban climate model ENVI-met. The best measure should be identified by comparing the range and effect of these scenarios. Simulations were run in three of the eight climatotopes (city center, suburban and open land site) to analyse the effectiveness of the mitigation strategies in several land use structures. These cover the range of values of all eight climatotopes and therefore provide representative results. In the model area of 21 ha total, the modified section in the different plan scenarios was 1 ha. Thus the effect of small-scale changes could be analysed. Such areas can arise due to population decline and structural changes and hold conversion potential. Emphasis was also laid on analysing the

  15. The effectiveness of cool and green roofs as urban heat island mitigation strategies

    NASA Astrophysics Data System (ADS)

    Li, Dan; Bou-Zeid, Elie; Oppenheimer, Michael

    2014-05-01

    Mitigation of the urban heat island (UHI) effect at the city-scale is investigated using the Weather Research and Forecasting (WRF) model in conjunction with the Princeton Urban Canopy Model (PUCM). Specifically, the cooling impacts of green roof and cool (white/high-albedo) roof strategies over the Baltimore-Washington metropolitan area during a heat wave period (7 June-10 June 2008) are assessed using the optimal set-up of WRF-PUCM described in the companion paper by Li and Bou-Zeid (2014). Results indicate that the surface UHI effect (defined based on the urban-rural surface temperature difference) is reduced significantly more than the near-surface UHI effect (defined based on urban-rural 2 m air temperature difference) when these mitigation strategies are adopted. In addition, as the green and cool roof fractions increase, the surface and near-surface UHIs are reduced almost linearly. Green roofs with relatively abundant soil moisture have comparable effect in reducing the surface and near-surface UHIs to cool roofs with an albedo value of 0.7. Significant indirect effects are also observed for both green and cool roof strategies; mainly, the low-level advection of atmospheric moisture from rural areas into urban terrain is enhanced when the fraction of these roofs increases, thus increasing the humidity in urban areas. The additional benefits or penalties associated with modifications of the main physical determinants of green or cool roof performance are also investigated. For green roofs, when the soil moisture is increased by irrigation, additional cooling effect is obtained, especially when the ‘unmanaged’ soil moisture is low. The effects of changing the albedo of cool roofs are also substantial. These results also underline the capabilities of the WRF-PUCM framework to support detailed analysis and diagnosis of the UHI phenomenon, and of its different mitigation strategies.

  16. Modeling of the Urban Heat Island (UHI) using WRF - Assessment of adaptation and mitigation strategies for the city of Stuttgart.

    NASA Astrophysics Data System (ADS)

    Fallmann, Joachim; Suppan, Peter; Emeis, Stefan

    2013-04-01

    Cities are warmer than their surroundings (called urban heat island, UHI). UHI influence urban atmospheric circulation, air quality, and ecological conditions. UHI leads to upward motion and compensating near-surface inflow from the surroundings which import rural trace substances. Chemical and aerosol formation processes are modified due to increased temperature, reduced humidity and modified urban-rural trace substance mixtures. UHIs produce enhanced heat stress for humans, animals and plants, less water availability and modified air quality. Growing cities and Climate Change will aggravate the UHI and its effects and urgently require adaptation and mitigation strategies. Prior to this, UHI properties must be assessed by surface observations, ground- and satellite-based vertical remote sensing and numerical modelling. The Weather Research and Forecasting Model (WRF) is an instrument to simulate and assess this phenomenon based on boundary conditions from observations and global climate models. Three urbanization schemes are available with WRF, which are tested during this study for different weather conditions in central Europe and will be enhanced if necessary. High resolution land use maps are used for this modeling effort. In situ measurements and Landsat thermal images are employed for validation of the results. The study will focus on the city of Stuttgart located in the south western part of Germany that is situated in a caldera-like orographic feature. This municipality has a long tradition in urban climate research and thus is well equipped with climatologic measurement stations. By using Geographical Information Systems (GIS), it is possible to simulate several scenarios for different surface properties. By increasing the albedo of roof and wall layers in the urban canopy model or by replacing urban land use by natural vegetation, simple urban planning strategies can be tested and the effect on urban heat island formation and air quality can be

  17. Using Remote Sensing Data and Research Results for Urban Heat Island Mitigation

    NASA Technical Reports Server (NTRS)

    Estes, Maury; Luvall, Jeffrey

    1999-01-01

    This paper provides information on the characteristics of the urban heat island, research designed to provide the data needed to develop effective urban heat island reduction strategies, and the development of local working groups to develop implementation plans. As background, an overview of research results on the urban heat island phenomenon and the resultant effect on energy usage and air quality will be explored. The use of more reflective roofing materials, paving materials, tree planting, and other initiatives will be explored as a basis for strategies to mitigate urban heat islands and improve the urban environment. Current efforts to use aircraft remote sensing data in Atlanta, Baton Rouge, Sacramento, and Salt Lake City and our work with non-profit organizations designated to lead public education and strategic development efforts will be presented. Efforts to organize working groups comprised of key stakeholders, the process followed in communicating research results, and methodology for soliciting feedback and incorporating ideas into local plans, policies and decision-making will be discussed. Challenges in developing and transferring data products and research results to stakeholders will be presented. It is our ultimate goal that such efforts be integrated into plans and/or decision models that encourage sustainable development.

  18. Evaluating the effectiveness of flood damage mitigation measures by the application of Propensity Score Matching

    NASA Astrophysics Data System (ADS)

    Hudson, P.; Botzen, W. J. W.; Kreibich, H.; Bubeck, P.; Aerts, J. C. J. H.

    2014-01-01

    The employment of damage mitigation measures by individuals is an important component of integrated flood risk management. In order to promote efficient damage mitigation measures, accurate estimates of their damage mitigation potential are required. That is, for correctly assessing the damage mitigation measures' effectiveness from survey data, one needs to control for sources of bias. A biased estimate can occur if risk characteristics differ between individuals who have, or have not, implemented mitigation measures. This study removed this bias by applying an econometric evaluation technique called Propensity Score Matching to a survey of German households along along two major rivers major rivers that were flooded in 2002, 2005 and 2006. The application of this method detected substantial overestimates of mitigation measures' effectiveness if bias is not controlled for, ranging from nearly € 1700 to € 15 000 per measure. Bias-corrected effectiveness estimates of several mitigation measures show that these measures are still very effective since they prevent between € 6700-14 000 of flood damage. This study concludes with four main recommendations regarding how to better apply Propensity Score Matching in future studies, and makes several policy recommendations.

  19. Evaluating the effectiveness of flood damage mitigation measures by the application of propensity score matching

    NASA Astrophysics Data System (ADS)

    Hudson, P.; Botzen, W. J. W.; Kreibich, H.; Bubeck, P.; Aerts, J. C. J. H.

    2014-07-01

    The employment of damage mitigation measures (DMMs) by individuals is an important component of integrated flood risk management. In order to promote efficient damage mitigation measures, accurate estimates of their damage mitigation potential are required. That is, for correctly assessing the damage mitigation measures' effectiveness from survey data, one needs to control for sources of bias. A biased estimate can occur if risk characteristics differ between individuals who have, or have not, implemented mitigation measures. This study removed this bias by applying an econometric evaluation technique called propensity score matching (PSM) to a survey of German households along three major rivers that were flooded in 2002, 2005, and 2006. The application of this method detected substantial overestimates of mitigation measures' effectiveness if bias is not controlled for, ranging from nearly EUR 1700 to 15 000 per measure. Bias-corrected effectiveness estimates of several mitigation measures show that these measures are still very effective since they prevent between EUR 6700 and 14 000 of flood damage per flood event. This study concludes with four main recommendations regarding how to better apply propensity score matching in future studies, and makes several policy recommendations.

  20. 'Heat from Above' Heat Capacity Measurements in Liquid He-4

    NASA Technical Reports Server (NTRS)

    Lee, R. A. M.; Chatto, A.; Sergatskov, D. A.; Babkin, A. V.; Boyd, S. T. P.; Churilov, A. M.; McCarson, T. D.; Chui, T. C. P.; Day, P. K.; Dunca, R. V.

    2003-01-01

    We have made heat capacity measurements of superfluid He-4 at temperatures very close to the lambda point, T(sub lambda) , in a constant heat flux, Q, when the helium sample is heated from above. In this configuration the helium enters a self-organized (SOC) heat transport state at a temperature T(sub SOC)(Q), which for Q greater than or = 100 nW/sq cm lies below T(sub lambda). At low Q we observe little or no deviation from the bulk Q = 0 heat capacity up to T(sub SOC)(Q); beyond this temperature the heat capacity appears to be sharply depressed, deviating dramatically from its bulk behaviour. This marks the formation and propagation of a SOC/superfluid two phase state, which we confirm with a simple model. The excellent agreement between data and model serves as an independent confirmation of the existence of the SOC state. As Q is increased (up to 6 micron W/sq cm) we observe a Q dependant depression in the heat capacity that occurs just below T(sub SOC)(Q), when the entire sample is still superfluid. This is due to the emergence of a large thermal resistance in the sample, which we have measured and used to model the observed heat capacity depression. Our measurements of the superfluid thermal resistivity are a factor of ten larger than previous measurements by Baddar et al.

  1. Experimental and Numerical Studies of the Effects of Water Sprinkling on Urban Pavement on Heat Island Mitigation

    NASA Astrophysics Data System (ADS)

    Yoshioka, M.; Tosaka, H.; Nakagawa, K.

    2007-12-01

    One of the main causes of 'heat island phenomeno' is thought to be the artificial covers of the ground surface with asphalt or concrete which reduce greatly inherent cooling effect of water evaporation from soil surface. In this study, as a candidate method of mitigating the heat island the effects of the 'water sprinkling' on the pavements are discussed from field experiments and numerical studies. Three field experiments of water sprinkling on the asphalt/concrete pavements were performed in hot summer days in 2004-2006. For detecting the change in temperatures, the authors developed and used a 3-D measurements system which consists of two vertical planes with 6m high and 16m wide, and has network arrays of 102 thermistors distributed spatially in the planes. The temperatures measured in and around the water sprinkled area indicated that the ground surface temperature decreased 5 to 15 degrees uniformly in the water sprinkled area compared with those in the un-sprinkled area, while the relative decrease of atmospheric temperature was approximately up to 1 degree. The subsurface temperature at a depth of 14cm under the pavement decreased significantly and kept lower than that at the same depth in un-sprinkled area over the next morning. A numerical model was developed and applied to interpret the experimental results. It deals with the heat balance of radiation, sensible/latent heat transfer at the ground surface and heat conduction through the artificial and natural soil layer under ground. temperature and vapor conditions changes at and near ground surface were modeled by using the bulk formula.Good agreements between the calculated time-temperature profiles and the experimental ones were obtained by assuming adequate physical parameters and meteorological conditions. The model could be improved in order to evaluate the changes of temperature and vapor contents in atmosphere near the ground surface caused by aerodynamic turbulent diffusion.

  2. 30 CFR 250.223 - What mitigation measures information must accompany the EP?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE OUTER CONTINENTAL SHELF Plans and Information Contents of Exploration Plans (ep) § 250.223 What mitigation measures information must accompany the EP? (a... or mitigate environmental impacts from your proposed exploration activities, a description of...

  3. Estimating the CO2 mitigation potential of horizontal Ground Source Heat Pumps in the UK

    NASA Astrophysics Data System (ADS)

    Garcia-Gonzalez, R.; Verhoef, A.; Vidale, P. L.; Gan, G.; Chong, A.; Clark, D.

    2012-04-01

    By 2020, the UK will need to generate 15% of its energy from renewables to meet our contribution to the EU renewable energy target. Heating and cooling systems of buildings account for 30%-50% of the global energy consumption; thus, alternative low-carbon technologies such as horizontal Ground Couple Heat Pumps (GCHPs) can contribute to the reduction of anthropogenic CO2 emissions. Horizontal GCHPs currently represent a small fraction of the total energy generation in the UK. However, the fact that semi-detached and detached dwellings represent approximately 40% of the total housing stocks in the UK could make the widespread implementation of this technology particularly attractive in the UK and so could significantly increase its renewable energy generation potential. Using a simulation model, we analysed the dynamic interactions between the environment, the horizontal GCHP heat exchanger and typical UK dwellings, as well as their combined effect on heat pump performance and CO2 mitigation potential. For this purpose, a land surface model (JULES, Joint UK Land Environment Simulator), which calculates coupled soil heat and water fluxes, was combined with a heat extraction model. The analyses took into account the spatio-temporal variability of soil properties (thermal and hydraulic) and meteorological variables, as well as different horizontal GCHP configurations and a variety of building loads and heat demands. Sensitivity tests were performed for four sites in the UK with different climate and soil properties. Our results show that an installation depth of 1.0m would give us higher heat extractions rates, however it would be preferable to install the pipes slightly deeper to avoid the seasonal influence of variable meteorological conditions. A value of 1.5m for the spacing between coils (S) for a slinky configuration type is recommended to avoid thermal disturbances between neighbouring coils. We also found that for larger values of the spacing between the coils

  4. Experimental study designs to improve the evaluation of road mitigation measures for wildlife.

    PubMed

    Rytwinski, Trina; van der Ree, Rodney; Cunnington, Glenn M; Fahrig, Lenore; Findlay, C Scott; Houlahan, Jeff; Jaeger, Jochen A G; Soanes, Kylie; van der Grift, Edgar A

    2015-05-01

    An experimental approach to road mitigation that maximizes inferential power is essential to ensure that mitigation is both ecologically-effective and cost-effective. Here, we set out the need for and standards of using an experimental approach to road mitigation, in order to improve knowledge of the influence of mitigation measures on wildlife populations. We point out two key areas that need to be considered when conducting mitigation experiments. First, researchers need to get involved at the earliest stage of the road or mitigation project to ensure the necessary planning and funds are available for conducting a high quality experiment. Second, experimentation will generate new knowledge about the parameters that influence mitigation effectiveness, which ultimately allows better prediction for future road mitigation projects. We identify seven key questions about mitigation structures (i.e., wildlife crossing structures and fencing) that remain largely or entirely unanswered at the population-level: (1) Does a given crossing structure work? What type and size of crossing structures should we use? (2) How many crossing structures should we build? (3) Is it more effective to install a small number of large-sized crossing structures or a large number of small-sized crossing structures? (4) How much barrier fencing is needed for a given length of road? (5) Do we need funnel fencing to lead animals to crossing structures, and how long does such fencing have to be? (6) How should we manage/manipulate the environment in the area around the crossing structures and fencing? (7) Where should we place crossing structures and barrier fencing? We provide experimental approaches to answering each of them using example Before-After-Control-Impact (BACI) study designs for two stages in the road/mitigation project where researchers may become involved: (1) at the beginning of a road/mitigation project, and (2) after the mitigation has been constructed; highlighting real case

  5. Effects of Urban Heat Island Mitigation Strategies on Current and Future Meteorology of Atlanta, Georgia

    NASA Astrophysics Data System (ADS)

    Crosson, W. L.; Lapenta, W. M.; Griggs, L.; Kenna, G.; Johnson, H.; Dembek, S.

    2004-05-01

    The characterization of land use/land cover is an integral component of an ongoing air quality modeling project focused on evaluating strategies for reducing the Urban Heat Island (UHI) and improving air quality in Atlanta, Georgia. The `UHI mitigation strategies' applied in this project involve `Cool Communities' principles of high albedo pavement and roofing as well as increased urban tree canopy. These strategies have been developed based on input from local stakeholders and represent conditions that are attainable assuming broad-based support from local government and the community. In order to evaluate the impact of these strategies on urban meteorology (principally near-surface air temperature) and ultimately on air quality, mesoscale model simulations have been performed for the Atlanta region based on land use for 1999 and projected to 2030 using the Spatial Growth Model assuming `Business as Usual' development. Significant land use change associated with continuing urban sprawl is expected from now until 2030. Model simulations based on identical synoptic forcing were performed to evaluate the effects of local land use change on local and regional meteorology. For the 2030 case, results from `Business as Usual' and `UHI mitigation strategies' simulations will be compared. The impacts of higher urban albedo and increased tree cover will be examined separately and in combination.

  6. Identifiability in biobanks: models, measures, and mitigation strategies

    PubMed Central

    Loukides, Grigorios; Benitez, Kathleen; Clayton, Ellen Wright

    2013-01-01

    The collection and sharing of person-specific biospecimens has raised significant questions regarding privacy. In particular, the question of identifiability, or the degree to which materials stored in biobanks can be linked to the name of the individuals from which they were derived, is under scrutiny. The goal of this paper is to review the extent to which biospecimens and affiliated data can be designated as identifiable. To achieve this goal, we summarize recent research in identifiability assessment for DNA sequence data, as well as associated demographic and clinical data, shared via biobanks. We demonstrate the variability of the degree of risk, the factors that contribute to this variation, and potential ways to mitigate and manage such risk. Finally, we discuss the policy implications of these findings, particularly as they pertain to biobank security and access policies. We situate our review in the context of real data sharing scenarios and biorepositories. PMID:21739176

  7. Measuring the effects of stormwater mitigation on beach attendance.

    PubMed

    Atiyah, Perla; Pendleton, Linwood; Vaughn, Ryan; Lessem, Neil

    2013-07-15

    Many studies have used valuation techniques to predict the potential effect of environmental improvements on human use of coastal areas, but there is a lack of post hoc empirical evidence that these policies indeed affect the way people use coastal areas. A panel data approach is developed to statistically determine how storm drain diversions affected attendance at 26 beaches in Southern California. This study uses a 10-year time series of data to conduct a statistical analysis of attendance at beaches with and without diversions and before and after the diversions were installed, while controlling for all observable, confounding factors. Results indicate that beach attendance increased at beaches with diversions compared to those that did not have diversions (between 350,000 and 860,000 visits annually at a 95% confidence interval). Establishing this link between mitigation policies and human use patterns can lead to better management of coastal areas. PMID:23711842

  8. Numerical study of potential heat flux mitigation effects in the TCV snowflake divertor

    NASA Astrophysics Data System (ADS)

    Lunt, T.; Canal, G. P.; Duval, B. P.; Feng, Y.; Labit, B.; McCarthy, P.; Reimerdes, H.; Vijvers, W. A. J.; Wischmeier, M.

    2016-04-01

    We report on EMC3-Eirene simulations of the plasma and neutral particle transport the TCV boundary layer of a series of snowflake (SF) equilibria characterized by the normalized poloidal flux coordinate {ρx2} of the secondary X-point x 2. We refer to a snowflake plus (SF+) for {ρx2}<1 , a snowflake minus (SF-) for {ρx2}>1 and a single-null (SN) for |{ρx2}-1|\\gg 0 . Four effects are identified that have the potential to mitigate the heat flux density at the outer strike point in a LFS SF-where x 2 is located on the low field side of the primary X-point x 1: (1) a scrape-off layer heat flux splitting, (2) an impurity radiation cloud forming at x 2 (3) the increased connection length to the outer target and (4) increased transport between x 1 and x 2. The LFS SF- is thus expected to tolerate a larger power flux {{P}\\text{sep}} over the separatrix than a comparable SN configuration.

  9. Measuring Heat-Exchanger Water Leakage

    NASA Technical Reports Server (NTRS)

    Zampiceni, J.

    1986-01-01

    Water leakage in heat exchanger measured directly with help of electroytic hygrometer. In new technique, flow of nitrogen gas set up in one loop of heat exchanger. Other loop filled with water under pressure. Water concentration produced by leakage of water into nitrogen flow measured by hygrometer. New measurement method determines water concentrations up to 2,000 parts per million with accuracy of +/- 5 percent.

  10. Latent Heating from TRMM Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Tao, Wei-Kuo; Smith, E. A.; Adler, R.; Haddad, Z.; Hou, A.; Iguchi, T.; Kakar, R.; Krishnamurti, T.; Kummerow, C.; Lang, S.

    2004-01-01

    Rainfall production is the fundamental variable within the Earth's hydrological cycle because it is both the principal forcing term in surface water budgets and its energetics corollary, latent heating, is the principal source of atmospheric diabatic heating. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water. The properties of the vertical distribution of latent heat release modulate large-scale meridional and zonal circulations within the tropics - as well as modifying the energetic efficiencies of midlatitude weather systems. This paper focuses on the retrieval of latent heat release from satellite measurements generated by the Tropical Rainfall Measuring Mission (TRMM) satellite observatory, which was launched in November 1997 as a joint American-Japanese space endeavor. Since then, TRMM measurements have been providing an accurate four-dimensional account of rainfall over the global tropics and sub-tropics, information which can be used to estimate the space-time structure of latent heating across the Earth's low latitudes. The paper examines how the observed TRMM distribution of rainfall has advanced an understanding of the global water and energy cycle and its consequent relationship to the atmospheric general circulation and climate via latent heat release. A set of algorithm methodologies that are being used to estimate latent heating based on rain rate retrievals from the TRMM observations are described. The characteristics of these algorithms and the latent heating products that can be generated from them are also described, along with validation analyses of the heating products themselves. Finally, the investigation provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, concluding with remarks intended to stimulate further research on latent heating retrieval from satellites.

  11. Recent Advances in Measurement and Dietary Mitigation of Enteric Methane Emissions in Ruminants.

    PubMed

    Patra, Amlan K

    2016-01-01

    Methane (CH4) emission, which is mainly produced during normal fermentation of feeds by the rumen microorganisms, represents a major contributor to the greenhouse gas (GHG) emissions. Several enteric CH4 mitigation technologies have been explored recently. A number of new techniques have also been developed and existing techniques have been improved in order to evaluate CH4 mitigation technologies and prepare an inventory of GHG emissions precisely. The aim of this review is to discuss different CH4 measuring and mitigation technologies, which have been recently developed. Respiration chamber technique is still considered as a gold standard technique due to its greater precision and reproducibility in CH4 measurements. With the adoption of recent recommendations for improving the technique, the SF6 method can be used with a high level of precision similar to the chamber technique. Short-term measurement techniques of CH4 measurements generally invite considerable within- and between-animal variations. Among the short-term measuring techniques, Greenfeed and methane hood systems are likely more suitable for evaluation of CH4 mitigation studies, if measurements could be obtained at different times of the day relative to the diurnal cycle of the CH4 production. Carbon dioxide and CH4 ratio, sniffer, and other short-term breath analysis techniques are more suitable for on farm screening of large number of animals to generate the data of low CH4-producing animals for genetic selection purposes. Different indirect measuring techniques are also investigated in recent years. Several new dietary CH4 mitigation technologies have been explored, but only a few of them are practical and cost-effective. Future research should be directed toward both the medium- and long-term mitigation strategies, which could be utilized on farms to accomplish substantial reductions of CH4 emissions and to profitably reduce carbon footprint of livestock production systems. This review presents

  12. Recent Advances in Measurement and Dietary Mitigation of Enteric Methane Emissions in Ruminants

    PubMed Central

    Patra, Amlan K.

    2016-01-01

    Methane (CH4) emission, which is mainly produced during normal fermentation of feeds by the rumen microorganisms, represents a major contributor to the greenhouse gas (GHG) emissions. Several enteric CH4 mitigation technologies have been explored recently. A number of new techniques have also been developed and existing techniques have been improved in order to evaluate CH4 mitigation technologies and prepare an inventory of GHG emissions precisely. The aim of this review is to discuss different CH4 measuring and mitigation technologies, which have been recently developed. Respiration chamber technique is still considered as a gold standard technique due to its greater precision and reproducibility in CH4 measurements. With the adoption of recent recommendations for improving the technique, the SF6 method can be used with a high level of precision similar to the chamber technique. Short-term measurement techniques of CH4 measurements generally invite considerable within- and between-animal variations. Among the short-term measuring techniques, Greenfeed and methane hood systems are likely more suitable for evaluation of CH4 mitigation studies, if measurements could be obtained at different times of the day relative to the diurnal cycle of the CH4 production. Carbon dioxide and CH4 ratio, sniffer, and other short-term breath analysis techniques are more suitable for on farm screening of large number of animals to generate the data of low CH4-producing animals for genetic selection purposes. Different indirect measuring techniques are also investigated in recent years. Several new dietary CH4 mitigation technologies have been explored, but only a few of them are practical and cost-effective. Future research should be directed toward both the medium- and long-term mitigation strategies, which could be utilized on farms to accomplish substantial reductions of CH4 emissions and to profitably reduce carbon footprint of livestock production systems. This review presents

  13. Effectiveness of mitigation measures with constructed forested wetlands in Maryland

    USGS Publications Warehouse

    Perry, M.C.

    1997-01-01

    Intensive research on six constructed forested wetlands in Central Maryland was conducted in 1993-1996 to determine success of these habitats as functional forested wetlands for wildlife. Areas studied ranged in size from 2 to 35 acres and were constructed by private companies under contract with three mitigation agencies. Adjacent natural forested wetlands were used as reference sites where similar data were collected. Based on data from the first four years of this study it appears that it will take 35-50 years before these areas have forested wetland vegetation and wildlife similar to that found on mature forested wetlands. This long-time period is based on the high mortality and slow growth of nursery-stock trees and shrubs transplanted on the areas. Mortality and slow growth resulted mostly from excessive surface water on the sites. The level of ground water did not appear to be a factor in regard to transplant mortality. Green ash was the woody transplant species that had the least mortality. Sampling of vegetative ground cover with one-meter square quadrats showed the predominance of grasses and herbs. [abridged abstract

  14. Latent Heating from TRMM Satellite Measurements

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Smith, E.; Olson, W.

    2005-01-01

    Rainfall production is a fundamental process within the Earth;s hydrological cycle because it represents both a principal forcing term in surface water budgets, and its energetics corollary, latent heating, is the principal source of atmospheric diabatic heating. Latent heat release itself is a consequence of phase changes between the vapor, liquid, and frozen states of water. The properties of the vertical distribution of latent heat release modulate large-scale meridional and zonal circulations with the Tropics - as well as modify the energetic efficiencies of mid-latitude weather systems. This paper highlights the retrieval of observatory, which was launched in November 1997 as a joint American-Japanese space endeavor. Since then, TRMM measurements have been providing an accurate four-dimensional amount of rainfall over the global Tropics and sub-tropics - information which can be used to estimate the spacetime structure of latent heating across the Earth's low latitudes. A set of algorithm methodologies has and continues to be developed to estimate latent heating based on rain rate profile retrievals obtained from TRMM measurements. These algorithms are briefly described followed by a discussion of the foremost latent heating products that can be generate from them. The investigation then provides an overview of how TRMM-derived latent heating information is currently being used in conjunction with global weather and climate models, concluding with remarks intended to stimulate further research on latent heating retrieval from satellites.

  15. Pyrolytic graphite gauge for measuring heat flux

    NASA Technical Reports Server (NTRS)

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

    2002-01-01

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

  16. Compact Instruments Measure Heat Potential

    NASA Technical Reports Server (NTRS)

    2009-01-01

    Based in Huntsville, Alabama, AZ Technology Inc. is a woman- and veteran-owned business that offers expertise in electromechanical-optical design and advanced coatings. AZ Technology has received eight Small Business Innovation Research (SBIR) contracts with Marshall Space Flight Center for the development of spectral reflectometers and the measurement of surface thermal properties. The company uses a variety of measurement services and instruments, including the Spectrafire, a portable spectral emissometer it used to assist General Electric with the design of its award-winning Giraffe Warmer for neonatal intensive care units.

  17. Energy Saving Potentials and Air Quality Benefits of Urban Heat Island Mitigation

    SciTech Connect

    Akbari, Hashem

    2005-08-23

    Urban areas tend to have higher air temperatures than their rural surroundings as a result of gradual surface modifications that include replacing the natural vegetation with buildings and roads. The term ''Urban Heat Island'' describes this phenomenon. The surfaces of buildings and pavements absorb solar radiation and become extremely hot, which in turn warm the surrounding air. Cities that have been ''paved over'' do not receive the benefit of the natural cooling effect of vegetation. As the air temperature rises, so does the demand for air-conditioning (a/c). This leads to higher emissions from power plants, as well as increased smog formation as a result of warmer temperatures. In the United States, we have found that this increase in air temperature is responsible for 5-10% of urban peak electric demand for a/c use, and as much as 20% of population-weighted smog concentrations in urban areas. Simple ways to cool the cities are the use of reflective surfaces (rooftops and pavements) and planting of urban vegetation. On a large scale, the evapotranspiration from vegetation and increased reflection of incoming solar radiation by reflective surfaces will cool a community a few degrees in the summer. As an example, computer simulations for Los Angeles, CA show that resurfacing about two-third of the pavements and rooftops with reflective surfaces and planting three trees per house can cool down LA by an average of 2-3K. This reduction in air temperature will reduce urban smog exposure in the LA basin by roughly the same amount as removing the basin entire onroad vehicle exhaust. Heat island mitigation is an effective air pollution control strategy, more than paying for itself in cooling energy cost savings. We estimate that the cooling energy savings in U.S. from cool surfaces and shade trees, when fully implemented, is about $5 billion per year (about $100 per air-conditioned house).

  18. Nuclear reactor melt-retention structure to mitigate direct containment heating

    DOEpatents

    Tutu, Narinder K.; Ginsberg, Theodore; Klages, John R.

    1991-01-01

    A light water nuclear reactor melt-retention structure to mitigate the extent of direct containment heating of the reactor containment building. The structure includes a retention chamber for retaining molten core material away from the upper regions of the reactor containment building when a severe accident causes the bottom of the pressure vessel of the reactor to fail and discharge such molten material under high pressure through the reactor cavity into the retention chamber. In combination with the melt-retention chamber there is provided a passageway that includes molten core droplet deflector vanes and has gas vent means in its upper surface, which means are operable to deflect molten core droplets into the retention chamber while allowing high pressure steam and gases to be vented into the upper regions of the containment building. A plurality of platforms are mounted within the passageway and the melt-retention structure to direct the flow of molten core material and help retain it within the melt-retention chamber. In addition, ribs are mounted at spaced positions on the floor of the melt-retention chamber, and grid means are positioned at the entrance side of the retention chamber. The grid means develop gas back pressure that helps separate the molten core droplets from discharged high pressure steam and gases, thereby forcing the steam and gases to vent into the upper regions of the reactor containment building.

  19. CO₂ mitigation measures of power sector and its integrated optimization in China.

    PubMed

    Dai, Pan; Chen, Guang; Zhou, Hao; Su, Meirong; Bao, Haixia

    2012-01-01

    Power sector is responsible for about 40% of the total CO₂ emissions in the world and plays a leading role in climate change mitigation. In this study, measures that lower CO₂ emissions from the supply side, demand side, and power grid are discussed, based on which, an integrated optimization model of CO₂ mitigation (IOCM) is proposed. Virtual energy, referring to energy saving capacity in both demand side and the power grid, together with conventional energy in supply side, is unified planning for IOCM. Consequently, the optimal plan of energy distribution, considering both economic benefits and mitigation benefits, is figured out through the application of IOCM. The results indicate that development of demand side management (DSM) and smart grid can make great contributions to CO₂ mitigation of power sector in China by reducing the CO₂ emissions by 10.02% and 12.59%, respectively, in 2015, and in 2020. PMID:23213305

  20. CO2 Mitigation Measures of Power Sector and Its Integrated Optimization in China

    PubMed Central

    Dai, Pan; Chen, Guang; Zhou, Hao; Su, Meirong; Bao, Haixia

    2012-01-01

    Power sector is responsible for about 40% of the total CO2 emissions in the world and plays a leading role in climate change mitigation. In this study, measures that lower CO2 emissions from the supply side, demand side, and power grid are discussed, based on which, an integrated optimization model of CO2 mitigation (IOCM) is proposed. Virtual energy, referring to energy saving capacity in both demand side and the power grid, together with conventional energy in supply side, is unified planning for IOCM. Consequently, the optimal plan of energy distribution, considering both economic benefits and mitigation benefits, is figured out through the application of IOCM. The results indicate that development of demand side management (DSM) and smart grid can make great contributions to CO2 mitigation of power sector in China by reducing the CO2 emissions by 10.02% and 12.59%, respectively, in 2015, and in 2020. PMID:23213305

  1. Are heat waves susceptible to mitigate the expansion of a species progressing with global warming?

    PubMed Central

    Robinet, Christelle; Rousselet, Jérôme; Pineau, Patrick; Miard, Florie; Roques, Alain

    2013-01-01

    A number of organisms, especially insects, are extending their range in response of the increasing trend of warmer temperatures. However, the effects of more frequent climatic anomalies on these species are not clearly known. The pine processionary moth, Thaumetopoea pityocampa, is a forest pest that is currently extending its geographical distribution in Europe in response to climate warming. However, its population density largely decreased in its northern expansion range (near Paris, France) the year following the 2003 heat wave. In this study, we tested whether the 2003 heat wave could have killed a large part of egg masses. First, the local heat wave intensity was determined. Then, an outdoor experiment was conducted to measure the deviation between the temperatures recorded by weather stations and those observed within sun-exposed egg masses. A second experiment was conducted under laboratory conditions to simulate heat wave conditions (with night/day temperatures of 20/32°C and 20/40°C compared to the control treatment 13/20°C) and measure the potential effects of this heat wave on egg masses. No effects were noticed on egg development. Then, larvae hatched from these egg masses were reared under mild conditions until the third instar and no delayed effects on the development of larvae were found. Instead of eggs, the 2003 heat wave had probably affected directly or indirectly the young larvae that were already hatched when it occurred. Our results suggest that the effects of extreme climatic anomalies occurring over narrow time windows are difficult to determine because they strongly depend on the life stage of the species exposed to these anomalies. However, these effects could potentially reduce or enhance the average warming effects. As extreme weather conditions are predicted to become more frequent in the future, it is necessary to disentangle the effects of the warming trend from the effects of climatic anomalies when predicting the response of a

  2. Are heat waves susceptible to mitigate the expansion of a species progressing with global warming?

    PubMed

    Robinet, Christelle; Rousselet, Jérôme; Pineau, Patrick; Miard, Florie; Roques, Alain

    2013-09-01

    A number of organisms, especially insects, are extending their range in response of the increasing trend of warmer temperatures. However, the effects of more frequent climatic anomalies on these species are not clearly known. The pine processionary moth, Thaumetopoea pityocampa, is a forest pest that is currently extending its geographical distribution in Europe in response to climate warming. However, its population density largely decreased in its northern expansion range (near Paris, France) the year following the 2003 heat wave. In this study, we tested whether the 2003 heat wave could have killed a large part of egg masses. First, the local heat wave intensity was determined. Then, an outdoor experiment was conducted to measure the deviation between the temperatures recorded by weather stations and those observed within sun-exposed egg masses. A second experiment was conducted under laboratory conditions to simulate heat wave conditions (with night/day temperatures of 20/32°C and 20/40°C compared to the control treatment 13/20°C) and measure the potential effects of this heat wave on egg masses. No effects were noticed on egg development. Then, larvae hatched from these egg masses were reared under mild conditions until the third instar and no delayed effects on the development of larvae were found. Instead of eggs, the 2003 heat wave had probably affected directly or indirectly the young larvae that were already hatched when it occurred. Our results suggest that the effects of extreme climatic anomalies occurring over narrow time windows are difficult to determine because they strongly depend on the life stage of the species exposed to these anomalies. However, these effects could potentially reduce or enhance the average warming effects. As extreme weather conditions are predicted to become more frequent in the future, it is necessary to disentangle the effects of the warming trend from the effects of climatic anomalies when predicting the response of a

  3. Closing the Gap on Measuring Heat Waves

    NASA Astrophysics Data System (ADS)

    Perkins, S. E.; Alexander, L.

    2012-12-01

    Since the 4th IPCC assessment report, the scientific literature has established that anthropogenic climate change encompasses adverse changes in both mean climate conditions and extreme events, such as heat waves. Indeed, the affects of heat waves are felt across many different sectors, and have high economic, human, and physical impacts over many global regions. The spatial and monetary scale of heat wave impacts emphasizes the necessity of measuring and studying such events in an informative manner, which gives justice to the geographical region affected, the communities impacted, and the climatic fields involved. However, due to such wide interest in heat waves, their definition remains broad in describing a period of consecutive days where conditions are excessively hotter than normal. This has allowed for the employment of a plethora of metrics, which are usually unique to a given sector, or do not appropriately describe some of the important features of heat wave events. As such, it is difficult to ascertain a clear message regarding changes in heat waves, both in the observed record and in projections of future climate. This study addresses this issue by developing a multi-index, multi-aspect framework in which to measure heat waves. The methodology was constructed by assessing a wide range of heat wave and heat wave-related indices, both proposed and employed in the scientific literature. The broad implications of the occurrences, frequency and duration of heat waves and respective changes were also highly considered. The resulting indices measure three or more consecutive days where 1) maximum temperature exceeds the 90th percentile (TX90pct); 2) minimum temperature exceeds the 90th percentile (TN90pct); and 3) daily average temperature has a positive excess heat factor (EHF). The 90th percentiles from which TX90pct and TN90pct are calculated are based on 15-day windows for each calendar day, whereas the EHF is based upon two pre-calculated indices that

  4. Heat transfer measurements for Stirling machine cylinders

    NASA Technical Reports Server (NTRS)

    Kornhauser, Alan A.; Kafka, B. C.; Finkbeiner, D. L.; Cantelmi, F. C.

    1994-01-01

    The primary purpose of this study was to measure the effects of inflow-produced heat turbulence on heat transfer in Stirling machine cylinders. A secondary purpose was to provide new experimental information on heat transfer in gas springs without inflow. The apparatus for the experiment consisted of a varying-volume piston-cylinder space connected to a fixed volume space by an orifice. The orifice size could be varied to adjust the level of inflow-produced turbulence, or the orifice plate could be removed completely so as to merge the two spaces into a single gas spring space. Speed, cycle mean pressure, overall volume ratio, and varying volume space clearance ratio could also be adjusted. Volume, pressure in both spaces, and local heat flux at two locations were measured. The pressure and volume measurements were used to calculate area averaged heat flux, heat transfer hysteresis loss, and other heat transfer-related effects. Experiments in the one space arrangement extended the range of previous gas spring tests to lower volume ratio and higher nondimensional speed. The tests corroborated previous results and showed that analytic models for heat transfer and loss based on volume ratio approaching 1 were valid for volume ratios ranging from 1 to 2, a range covering most gas springs in Stirling machines. Data from experiments in the two space arrangement were first analyzed based on lumping the two spaces together and examining total loss and averaged heat transfer as a function of overall nondimensional parameter. Heat transfer and loss were found to be significantly increased by inflow-produced turbulence. These increases could be modeled by appropriate adjustment of empirical coefficients in an existing semi-analytic model. An attempt was made to use an inverse, parameter optimization procedure to find the heat transfer in each of the two spaces. This procedure was successful in retrieving this information from simulated pressure-volume data with artificially

  5. Measurement-based auralization methodology for the assessment of noise mitigation measures

    NASA Astrophysics Data System (ADS)

    Thomas, Pieter; Wei, Weigang; Van Renterghem, Timothy; Botteldooren, Dick

    2016-09-01

    The effect of noise mitigation measures is generally expressed by noise levels only, neglecting the listener's perception. In this study, an auralization methodology is proposed that enables an auditive preview of noise abatement measures for road traffic noise, based on the direction dependent attenuation of a priori recordings made with a dedicated 32-channel spherical microphone array. This measurement-based auralization has the advantage that all non-road traffic sounds that create the listening context are present. The potential of this auralization methodology is evaluated through the assessment of the effect of an L-shaped mound. The angular insertion loss of the mound is estimated by using the ISO 9613-2 propagation model, the Pierce barrier diffraction model and the Harmonoise point-to-point model. The realism of the auralization technique is evaluated by listening tests, indicating that listeners had great difficulty in differentiating between a posteriori recordings and auralized samples, which shows the validity of the followed approaches.

  6. Practical issues for using solar-reflective materials to mitigate urban heat islands

    NASA Astrophysics Data System (ADS)

    Bretz, Sarah; Akbari, Hashem; Rosenfeld, Arthur

    Solar-reflective or high-albedo, alternatives to traditionally absorptive urban surfaces such as rooftops and roadways can reduce cooling energy use and improve urban air quality at almost no cost. This paper presents information to support programs that mitigate urban heat islands with solar-reflective surfaces: estimates of the achievable increase in albedo for a variety of surfaces, issues related to the selection of materials and costs and benefits of using them. As an example, we present data for Sacramento, California. In Sacramento, we estimate that 20% of the 96 square mile area is dark roofing and 10% is dark pavement. Based on the change in albedo that is achievable for these surfaces, the overall albedo of Sacramento could be increased by 18%, a change that would produce significant energy savings and increase comfort within the city. Roofing market data indicate which roofing materials should be targeted for incentive programs. In 1995, asphalt shingle was used for over 65% of residential roofing area in the U.S. and 6% of commercial. Built-up roofing was used for about 5% of residential roofing and about 30% of commercial roofing. Single-ply membranes covered about 9% of the residential roofing area and over 30% of the commercial area. White, solar-reflective alternatives are presently available for these roofing materials but a low- first-cost, solar-reflective alternative to asphalt shingles is needed to capture the sloped-roof market. Since incoming solar radiation has a large non-visible component, solar-reflective materials can also be produced in a variety of colors.

  7. Cooperative measures to mitigate Asia-Pacific maritime conflicts.

    SciTech Connect

    Chai, Wen-Chung

    2003-05-01

    The economies of East Asia are predominantly export based and, therefore, place special emphasis on the security of the sea lines of communication (SLOCs). Due to economic globalization, the United States shares these concerns. Cooperative measures by the concerned parties could reduce the potential for disruption by maritime conflicts. Primary threats against the SLOCs are disputes over the resources under the seas, disputes over some small island groups, disputes between particular parties (China-Taiwan and North-South Korea), or illegal activities like smuggling, piracy, or terrorism. This paper provides an overview on these threats, issue by issue, to identify common elements and needed cooperation. Cooperation on other topics such as search and rescue, fisheries protection, and oil spill response may help support improved relations to prevent maritime conflicts. Many technologies can help support maritime cooperation, including improved communications links, tracking and emergency beacon devices, and satellite imaging. Appropriate technical and political means are suggested for each threat to the SLOCs.

  8. Evaluating mitigation measures for diffuse pollution across time and space (Invited)

    NASA Astrophysics Data System (ADS)

    Quinton, J.; Deasy, C.

    2010-12-01

    National governments around the world are placing greater emphasis on reducing diffuse sources of pollutants. This has shifted attention away from end of pipe solutions to clearly identifiable pollutant problems, to catchment-wide interventions using tools that are often poorly understood and which may produce unexpected outcomes. Variability and lags in the temporal and spatial pollutant signal, complex behaviour affecting the mitigation process, and difficulties in gaining sufficient data for robust statistical analysis all lead to uncertainty in the results of mitigation trials. Nethertheless, pressure from policy makers forces scientists to make recommendations on the implementation of mitigation measures and their location within a watershed The diffuse pollution control issue becomes increasingly complicated as multiple diffuse pollutants are often present, and while mitigation measures may address one set of pollutants, interventions may increase problems associated with others and lead to ‘pollution swapping’ These issues become even more complex, as good water quality is only one of the services demanded from the watershed, and other land use pressures, including productivity, flood storage and biodiversity must also be considered. In this paper we explore these themes, making use of data and experiences gained from the Mitigation of Phosphorus and Sediment Project (funded by the UK Department for Environment, Food and Rural Affairs).

  9. Modeling, measuring, and mitigating instability growth in liner implosions on Z

    NASA Astrophysics Data System (ADS)

    Peterson, Kyle

    2015-11-01

    Electro-thermal instabilities result from non-uniform heating due to temperature dependence in the conductivity of a material. In this talk, we will discuss the role of electro-thermal instabilities on the dynamics of magnetically accelerated implosion systems. We present simulations that show electro-thermal instabilities form immediately after the surface material of a conductor melts and can act as a significant seed to subsequent magneto-Rayleigh-Taylor (MRT) instability growth. We discuss measurement results from experiments performed on Sandia National Laboratories Z accelerator to investigate signatures of electro-thermal instability growth on well-characterized initially solid aluminum or beryllium rods driven with a 20 MA, 100 ns risetime current pulse. These measurements show good agreement with electro-thermal instability simulations and exhibit larger instability growth than can be explained by MRT theory alone. Recent experiments have confirmed simulation predictions of dramatically reduced instability growth in solid metallic rods when thick dielectric coatings are used to mitigate density perturbations arising from the electro-thermal instability. These results provide further evidence that the inherent surface roughness of the target is not the dominant seed for the MRT instability, in contrast with most inertial confinement fusion approaches. These results suggest a new technique for substantially reducing the integral MRT growth in magnetically driven implosions. Indeed, recent results on the Z facility with 100 km/s Al and Be liner implosions show substantially reduced growth. These new results include axially magnetized, CH-coated beryllium liner radiographs in which the inner liner surface is observed to be remarkably straight and uniform at a radius of about 120 microns (convergence ratio ~20). Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under

  10. 30 CFR 250.223 - What mitigation measures information must accompany the EP?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 2 2011-07-01 2011-07-01 false What mitigation measures information must accompany the EP? 250.223 Section 250.223 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION, AND ENFORCEMENT, DEPARTMENT OF THE INTERIOR OFFSHORE OIL AND GAS AND SULPHUR OPERATIONS IN THE...

  11. REVIEW OF SELECTED STATE-OF-THE-ART APPLICATIONS OF DIAGNOSTIC MEASUREMENTS FOR RADON MITIGATION PLANNING

    EPA Science Inventory

    Since late-1984, EPA's AEERL has supported a program to develop and demonstrate radon mitigation techniques for single-family detached dwellings. As part of the program, projects have been started directed at developing and demonstrating the use of diagnostic measurements in all ...

  12. MEASUREMENT OF SPECIFIC HEAT CAPACITY OF SALTSTONE

    SciTech Connect

    Harbour, J; Vickie Williams, V

    2008-09-29

    One of the goals of the Saltstone variability study is to identify (and quantify the impact of) the operational and compositional variables that control or influence the important processing and performance properties of Saltstone grout mixtures. The heat capacity of the Saltstone waste form is one of the important properties of Saltstone mixes that was last measured at SRNL in 1997. It is therefore important to develop a core competency for rapid and accurate analysis of the specific heat capacity of the Saltstone mixes in order to quantify the impact of compositional and operational variations on this property as part of the variability study. The heat capacity, coupled with the heat of hydration data obtained from isothermal calorimetry for a given Saltstone mix, can be used to predict the maximum temperature increase in the cells within the vaults of the Saltstone Disposal Facility (SDF). The temperature increase controls the processing rate and the pour schedule. The maximum temperature is also important to the performance properties of the Saltstone. For example, in mass pours of concrete or grout of which Saltstone is an example, the maximum temperature increase and the maximum temperature difference (between the surface and the hottest location) are controlled to ensure durability of the product and prevent or limit the cracking caused by the thermal gradients produced during curing. This report details the development and implementation of a method for the measurement of the heat capacities of Saltstone mixes as well as the heat capacities of the cementitious materials of the premix and the simulated salt solutions used to batch the mixes. The developed method utilizes the TAM Air isothermal calorimeter and takes advantage of the sophisticated heat flow measurement capabilities of the instrument. Standards and reference materials were identified and used to validate the procedure and ensure accuracy of testing. Heat capacities of Saltstone mixes were

  13. Biogeophysical benefits of no-till agriculture for mitigating heat wave impacts

    NASA Astrophysics Data System (ADS)

    Davin, Edouard; Seneviratne, Sonia; Ciais, Philippe; Olioso, Albert; Wang, Tao

    2014-05-01

    Changes in agricultural practices are considered a possible option to mitigate climate change[1]. In particular, reducing or suppressing tillage (no-till) may have the potential to sequester carbon in soils, which could help slow global warming[1]. On the other hand, such practices also have a direct effect on regional climate by altering the physical properties of the land surface[2]. These biogeophysical effects, however, are still poorly known. Here we show that no-till management increases the surface albedo of croplands in summer and that the resulting cooling effect is amplified during hot extremes, thus attenuating peak temperatures reached during heatwaves. Using a regional climate model accounting for the observed effects of no-till farming on surface albedo, as well as possible reductions in soil evaporation, we investigate the potential consequences of a full conversion to no-till agriculture in Europe. We find that the summer cooling from cropland albedo increase is strongly amplified during hot summer days, when surface albedo has more impact on the Earth's radiative balance due to clear-sky conditions. The reduced evaporation associated with the crop residue cover tends to counteract the albedo-induced cooling, but during hot days the albedo effect is the dominating factor. For heatwave summer days the local cooling effect gained from no-till practice is of the order of 2 degrees. The identified asymmetric impact of surface albedo change on summer temperature opens new avenues for climate engineering measures targeting high impact events rather than mean climate properties. References: [1] Smith, P., D. Martino, Z. Cai, D. Gwary, H. Janzen, P. Kumar, B. McCarl, S. Ogle, F. O'Mara, C. Rice, B. Scholes, O. Sirotenko (2007): Agriculture. In Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [B. Metz, O.R. Davidson, P.R. Bosch, R. Dave, L.A. Meyer (eds

  14. Hot spot mitigation in microprocessors by application of single phase microchannel heat sink and microprocessor floor planning

    NASA Astrophysics Data System (ADS)

    Chauhan, Anjali

    Poor thermal management in high frequency microprocessors results in thermal and mechanical stresses in the chip due to leakage losses, occurrence of hot spots and large temperature gradients. A micro-fluidics based cooling scheme of single phase microchannel heat sinks is found to be most promising cooling solution. Microchannel heat sinks have high cooling capability because of its high surface area to volume ratio and high heat transfer coefficient. Besides the fluid flow, heat transfer mechanism in microchannel heat sinks is affected by its installation on the microprocessor chip. Since microchannel heat sinks are capable of reducing only the average temperature rise of the microprocessor chip, technique of microprocessor floor planning can be applied to reduce hot spot temperature, mitigate multiple hot spots and reduce large temperature gradients on the surface of microprocessor chip. In this study, adequate installation of the microchannel heat sink on the processor chip has been proposed to extract maximum heat from the device. Microprocessor floor planning has also been explored to obtain an optimum chip floor plan on grounds of low performance penalty, low hot spot temperature and minimum number hot spots. The dependence of maximum hot spot temperature of the chip on pressure gradient across the microchannels has also been discussed.

  15. Nutrient pollution mitigation measures across Europe are resilient under future climate

    NASA Astrophysics Data System (ADS)

    Wade, Andrew; Skeffington, Richard; Couture, Raoul; Erlandsson, Martin; Groot, Simon; Halliday, Sarah; Harezlak, Valesca; Hejzlar, Joseph; Jackson-Blake, Leah; Lepistö, Ahti; Papastergiadou, Eva; Psaltopoulos, Demetrios; Riera, Joan; Rankinen, Katri; Skuras, Dimitris; Trolle, Dennis; Whitehead, Paul; Dunn, Sarah; Bucak, Tuba

    2016-04-01

    The key results from the application of catchment-scale biophysical models to assess the likely effectiveness of nutrient pollution mitigation measures set in the context of projected land management and climate change are presented. The assessment is based on the synthesis of modelled outputs of daily river flow, river and lake nitrogen and phosphorus concentrations, and lake chlorophyll-a, for baseline (1981-2010) and scenario (2031-2060) periods for nine study sites across Europe. Together the nine sites represent a sample of key climate and land management types. The robustness and uncertainty in the daily, seasonal and long-term modelled outputs was assessed prior to the scenario runs. Credible scenarios of land-management changes were provided by social scientists and economists familiar with each study site, whilst likely mitigation measures were derived from local stakeholder consultations and cost-effectiveness assessments. Modelled mitigation options were able to reduce nutrient concentrations, and there was no evidence here that they were less effective under future climate. With less certainty, mitigation options could affect the ecological status of waters at these sites in a positive manner, leading to improvement in Water Framework Directive status at some sites. However, modelled outcomes for sites in southern Europe highlighted that increased evaporation and decreased precipitation will cause much lower flows leading to adverse impacts of river and lake ecology. Uncertainties in the climate models, as represented by three GCM-RCM combinations, did not affect this overall picture much.

  16. Heat capacity measurements - Progress in experimental techniques

    NASA Astrophysics Data System (ADS)

    Lakshmikumar, S. T.; Gopal, E. S. R.

    1981-11-01

    The heat capacity of a substance is related to the structure and constitution of the material and its measurement is a standard technique of physical investigation. In this review, the classical methods are first analyzed briefly and their recent extensions are summarized. The merits and demerits of these methods are pointed out. The newer techniques such as the a.c. method, the relaxation method, the pulse methods, the laser flash calorimetry and other methods developed to extend the heat capacity measurements to newer classes of materials and to extreme conditions of sample geometry, pressure and temperature are comprehensively reviewed. Examples of recent work and details of the experimental systems are provided for each method. The introduction of automation in control systems for the monitoring of the experiments and for data processing is also discussed. Two hundred and eight references and 18 figures are used to illustrate the various techniques.

  17. Cost-benefit analysis of alternative LNG vapor-mitigation measures. Topical report, September 14, 1987-January 15, 1991

    SciTech Connect

    Atallah, S.

    1992-06-25

    A generalized methodology is presented for comparing the costs and safety benefits of alternative hazard mitigation measures for a large LNG vapor release. The procedure involves the quantification of the risk to the public before and after the application of LNG vapor mitigation measures. In the study, risk was defined as the product of the annual accident frequency, estimated from a fault tree analysis, and the severity of the accident. Severity was measured in terms of the number of people who may be exposed to 2.5% or higher concentration. The ratios of the annual costs of the various mitigation measures to their safety benefits (as determined by the differences between the risk before and after mitigation measure implementation), were then used to identify the most cost-effective approaches to vapor cloud mitigation.

  18. Measurement of heat conduction through stacked screens

    NASA Technical Reports Server (NTRS)

    Lewis, M. A.; Kuriyama, T.; Kuriyama, F.; Radebaugh, R.

    1998-01-01

    This paper describes the experimental apparatus for the measurement of heat conduction through stacked screens as well as some experimental results taken with the apparatus. Screens are stacked in a fiberglass-epoxy cylinder, which is 24.4 mm in diameter and 55 mm in length. The cold end of the stacked screens is cooled by a Gifford-McMahon (GM) cryocooler at cryogenic temperature, and the hot end is maintained at room temperature. Heat conduction through the screens is determined from the temperature gradient in a calibrated heat flow sensor mounted between the cold end of the stacked screens and the GM cryocooler. The samples used for these experiments consisted of 400-mesh stainless steel screens, 400-mesh phosphor bronze screens, and two different porosities of 325-mesh stainless steel screens. The wire diameter of the 400-mesh stainless steel and phosphor bronze screens was 25.4 micrometers and the 325-mesh stainless steel screen wire diameters were 22.9 micrometers and 27.9 micrometers. Standard porosity values were used for the experimental data with additional porosity values used on selected experiments. The experimental results showed that the helium gas between each screen enhanced the heat conduction through the stacked screens by several orders of magnitude compared to that in vacuum. The conduction degradation factor is the ratio of actual heat conduction to the heat conduction where the regenerator material is assumed to be a solid rod of the same cross sectional area as the metal fraction of the screen. This factor was about 0.1 for the stainless steel and 0.022 for the phosphor bronze, and almost constant for the temperature range of 40 to 80 K at the cold end.

  19. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    SciTech Connect

    Hollmann, E. M.; Moyer, R. A.; Commaux, N.; Shiraki, D.; Eidietis, N. W.; Parks, P. B.; Lasnier, C. J.

    2015-10-15

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. This IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.

  20. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    SciTech Connect

    Hollmann, E. M.; Commaux, Nicolas J. C.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, Daisuke

    2015-10-12

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but this phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. Furthermore, this IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.

  1. Methane mitigation in cities: how new measurements and partnerships can contribute to emissions reduction strategies

    NASA Astrophysics Data System (ADS)

    Hopkins, F. M.; Bush, S. E.; Ehleringer, J. R.; Lai, C. T.; Rambo, J. P.; Wiggins, E. B.; Miu, J. C. L.; Carranza, V.; Randerson, J. T.

    2014-12-01

    Cities generate a large fraction of anthropogenic methane emissions that are increasing with urbanization and greater reliance on natural gas as fuel. New measurements of methane in cities suggest an as-yet unrealized potential for city-scale methane mitigation. We present high-resolution methane observations from four cities in North America to demonstrate the utility of methane surveys for identifying urban methane sources. We used portable, continuous on-road measurements to determine the spatial distribution of methane in Fairbanks, Los Angeles, Salt Lake City, and San Diego. Across cities, methane tended to be highly concentrated in space, suggesting discrete, point emission sources. Elevated methane levels were found near known emission sources, such as landfills, wastewater treatment facilities, and natural gas-fueled power plants, and revealed the location of fugitive leaks in natural gas infrastructure. The mix of sources and sizes of methane leaks varied among cities, highlighting a need for locally adaptive emissions regulation. Urban methane observations can inform anthropogenic processes in development of methane mitigation strategies. We discuss specific examples of how continuous atmospheric measurements can enhance the design of mitigation strategies in these cities, and potential contributions of these approaches to cross-sectoral efforts to reduce methane emissions at the city level.

  2. Acquisition systems for heat transfer measurement

    SciTech Connect

    De Witt, R.J.

    1983-01-01

    Practical heat transfer data acquisition systems are normally characterized by the need for high-resolution, low-drift, low-speed recording devices. Analog devices such as strip chart or circular recorders and FM analog magnetic tape have excellent resolution and work well when data will be presented in temperature versus time format only and need not be processed further. Digital systems are more complex and require an understanding of the following components: digitizing devices, interface bus types, processor requirements, and software design. This paper discusses all the above components of analog and digital data acquisition, as they are used in current practice. Additional information on thermocouple system analysis will aid the user in developing accurate heat transfer measuring systems.

  3. Aerial measurement of heat loss: Phase II

    SciTech Connect

    Not Available

    1982-07-01

    The purpose of the program described was to develop techniques to reduce or eliminate some of the variables associated with thermogram analysis in order to provide more objective interpretation of the data collected with greater potential for accuracy. A procedure is given for measuring temperature which accounts for atmospheric, background, and differential emissivity effects. The residual error was found to be 1.0/sup 0/C. A technique was then identified and developed for determining heat loss lovels from roof top surface temperature data. A thermal integrity factor was defined as a function of insulation level and thermostat setting. Comparing these thermal integrity factors with aerial thermography data indicates that aerial thermography can be used to objectively and confidently define heat loss levels from building roofs. (LEW)

  4. Understanding Coronal Heating with Emission Measure Distributions

    NASA Technical Reports Server (NTRS)

    Klimchik, James A.; Tripathi, Durgesh; Bradshaw, Stephen J.; Mason, Helen E.

    2011-01-01

    It is widely believed that the cross-field spatial scale of coronal heating is small, so that the fundamental plasma structures (loop strands) are spatially unresolved. We therefore must appeal to diagnostic techniques that are not strongly affected by spatial averaging. One valuable observable is the emission measure distribution, EM(T), which indicates how much material is present at each temperature. Using data from the Extreme-ultraviolet Imaging Spectrograph on the Hinode mission, we have determined emission measure distributions in the cores of two active regions. The distributions have power law slopes of approximately 2.4 coolward of the peak. We compare these slopes, as well as the amount of emission measure at very high temperature, with the predictions of a series of models. The models assume impulsive heating (nanoflares) in unresolved strands and take full account of non equilibrium ionization. A variety of nanoflare properties and initial conditions are considered. We also comment on the selection of spectral lines for upcoming missions like Solar Orbiter.

  5. Measuring heat leak with a heatmeter

    SciTech Connect

    Kuchnir, M.; Gonczy, J.D.; Tague, L.

    1985-08-01

    The heatmeter or more precisely the heatflowmeter is a device based on thermal conductivity measuring techniques. It consists of a thermal conducting body between two thermometers, with provisions for thermal connections and calibration. The paper describes the design, construction details, calibration and performance of one such heatmeter for use with heat reservoirs at either 4.2 K or 78 K. Near 4.2 K it has a sensitivity of 10 ..mu..W and requires less than a minute to reach steady state. Near 78 K its sensitivity is 10 MW and requires 25 minutes to reach steady state.

  6. Work measurement in a quantum heat engine

    NASA Astrophysics Data System (ADS)

    Bariani, Francesco; Zhang, Keye; Dong, Ying; Meystre, Pierre

    2015-05-01

    We consider an optomechanical quantum heat engine operating on an Otto cycle for photon-phonon polaritons, the working substance of the engine. We discuss both the average value and quantum fluctuations of its work output, concentrating in particular on the effects of quantum non-adiabaticity due to the finite duration of the cycle. We also determine the quantum back-action of both absorptive and dispersive continuous measurements of the work, and quantify their impact on the Curzon-Ahlborn engine efficiency at maximum power and its fluctuations. We ackowledge financial support from National Basic Research Program of China, NSF, ARO and the DARPA QuaSAR programs

  7. Retrieval of Latent Heating from TRMM Measurements

    NASA Technical Reports Server (NTRS)

    Tao, W.-K.; Smith, E. A.; Adler, R. F.; Hou, A. Y.; Meneghini, R.; Simpson, J.; Haddad, Z. S.; Iguchi, T.; Satoh, S.; Kakar, R.; Krishnamurti, T. N.; Kummerow, C. D.; Lang, S.; Nakamura, K.; Nakazawa, T.; Okamoto, K.; Shige, S.; Olson, W. S.; Takayabu, Y.; Tripoli, G. J.; Yang, S.

    2006-01-01

    Precipitation, in driving the global hydrological cycle, strongly influences the behavior of the Earth's weather and climate systems and is central to their variability. Two-thirds of the global rainfall occurs over the Tropics, which leads to its profound effect on the general circulation of the atmosphere. This is because its energetic equivalent, latent heating (LH), is the tropical convective heat engine's primary fuel source as originally emphasized by Riehl and Malkus (1958). At low latitudes, LH stemming from extended bands of rainfall modulates large-scale zonal and meridional circulations and their consequent mass overturnings (e.g., Hartmann et al. 1984; Hack and Schubert 1990). Also, LH is the principal energy source in the creation, growth, vertical structure, and propagation of long-lived tropical waves (e.g., Puri 1987; Lau and Chan 1988). Moreover, the distinct vertical distribution properties of convective and stratiform LH profiles help influence climatic outcomes via their tight control on large-scale circulations (Lau and Peng 1987; Nakazawa 1988; Sui and Lau 1988; Emanuel et al. 1994; Yanai et al. 2000; Sumi and Nakazawa 2002; Schumacher et al. 2004). The purpose of this paper is to describe how LH profiles are being derived from satellite precipitation rate retrievals, focusing on those being made with Tropical Rainfall Measuring Mission (TRMM) satellite measurements.

  8. Meteorological insights from planetary heat flow measurements

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.

    2015-04-01

    Planetary heat flow measurements are made with a series of high-precision temperature sensors deployed in a column of regolith to determine the geothermal gradient. Such sensors may, however, be susceptible to other influences, especially on worlds with atmospheres. First, pressure fluctuations at the surface may pump air in and out of pore space leading to observable, and otherwise unexpected, temperature fluctuations at depth. Such pumping is important in subsurface radon and methane transport on Earth: evidence of such pumping may inform understanding of methane or water vapor transport on Mars. Second, the subsurface profile contains a muted record of surface temperature history, and such measurements on other worlds may help constrain the extent to which Earth's Little Ice Age was directly solar-forced, versus volcanic-driven and/or amplified by climate feedbacks.

  9. Measurement and mitigation of nitrous oxide emissions from a high nitrogen input vegetable system

    NASA Astrophysics Data System (ADS)

    Lam, Shu Kee; Suter, Helen; Davies, Rohan; Bai, Mei; Sun, Jianlei; Chen, Deli

    2015-02-01

    The emission and mitigation of nitrous oxide (N2O) from high nitrogen (N) vegetable systems is not well understood. Nitrification inhibitors are widely used to decrease N2O emissions in many cropping systems. However, most N2O flux measurements and inhibitor impacts have been made with small chambers and have not been investigated at a paddock-scale using micrometeorological techniques. We quantified N2O fluxes over a four ha celery paddock using open-path Fourier Transform Infrared spectroscopy in conjunction with a backward Lagrangian stochastic model, in addition to using a closed chamber technique. The celery crop was grown on a sandy soil in southern Victoria, Australia. The emission of N2O was measured following the application of chicken manure and N fertilizer with and without the application of a nitrification inhibitor 3, 4-dimethyl pyrazole phosphate (DMPP). The two techniques consistently demonstrated that DMPP application reduced N2O emission by 37-44%, even though the N2O fluxes measured by a micrometeorological technique were more than 10 times higher than the small chamber measurements. The results suggest that nitrification inhibitors have the potential to mitigate N2O emission from intensive vegetable production systems, and that the national soil N2O emission inventory assessments and modelling predictions may vary with gas measurement techniques.

  10. Measurement and mitigation of nitrous oxide emissions from a high nitrogen input vegetable system.

    PubMed

    Lam, Shu Kee; Suter, Helen; Davies, Rohan; Bai, Mei; Sun, Jianlei; Chen, Deli

    2015-01-01

    The emission and mitigation of nitrous oxide (N2O) from high nitrogen (N) vegetable systems is not well understood. Nitrification inhibitors are widely used to decrease N2O emissions in many cropping systems. However, most N2O flux measurements and inhibitor impacts have been made with small chambers and have not been investigated at a paddock-scale using micrometeorological techniques. We quantified N2O fluxes over a four ha celery paddock using open-path Fourier Transform Infrared spectroscopy in conjunction with a backward Lagrangian stochastic model, in addition to using a closed chamber technique. The celery crop was grown on a sandy soil in southern Victoria, Australia. The emission of N2O was measured following the application of chicken manure and N fertilizer with and without the application of a nitrification inhibitor 3, 4-dimethyl pyrazole phosphate (DMPP). The two techniques consistently demonstrated that DMPP application reduced N2O emission by 37-44%, even though the N2O fluxes measured by a micrometeorological technique were more than 10 times higher than the small chamber measurements. The results suggest that nitrification inhibitors have the potential to mitigate N2O emission from intensive vegetable production systems, and that the national soil N2O emission inventory assessments and modelling predictions may vary with gas measurement techniques. PMID:25644694

  11. The influence of governmental mitigation measures on contamination characteristics of PM(2.5) in Beijing.

    PubMed

    Chen, Yuan; Schleicher, Nina; Chen, Yizhen; Chai, Fahe; Norra, Stefan

    2014-08-15

    Beijing, the capital of China, has become one of the most air-polluted cities due to its rapid economic growth. Weekly PM2.5 samples-collected continuously from 2007 to 2010-were used to study the contamination characteristics of atmospheric particles and effects of governmental mitigation measures especially since the 2008 Summer Olympic Games. PM2.5 mass concentrations during the sampling period were reduced compared to the previous studies before 2005, although they were still too high in comparison with environmental standards of China and many other countries as well as WHO standards. Results of principle component analysis show that elements of primary anthropogenic origin had an obvious decline while elements mainly from the natural environment kept a relatively stable course. The governmental macro-control measures influenced both anthropogenic and geogenic sources, but they also led to some pollution peaks prior to implementation of the respective measures. Some element concentrations correlated to the restrictiveness of relative measures, especially during different traffic restrictions. The comparison with other countries and international standards shows that there is a long way to go in order to improve air quality in Beijing, and that governmental mitigation measures need to be continued and reinforced. PMID:24887192

  12. Micrometeorological simulations to predict the impacts of heat mitigation strategies on pedestrian thermal comfort in a Los Angeles neighborhood

    NASA Astrophysics Data System (ADS)

    Taleghani, Mohammad; Sailor, David; Ban-Weiss, George A.

    2016-02-01

    The urban heat island impacts the thermal comfort of pedestrians in cities. In this paper, the effects of four heat mitigation strategies on micrometeorology and the thermal comfort of pedestrians were simulated for a neighborhood in eastern Los Angeles County. The strategies investigated include solar reflective ‘cool roofs’, vegetative ‘green roofs’, solar reflective ‘cool pavements’, and increased street-level trees. A series of micrometeorological simulations for an extreme heat day were carried out assuming widespread adoption of each mitigation strategy. Comparing each simulation to the control simulation assuming current land cover for the neighborhood showed that additional street-trees and cool pavements reduced 1.5 m air temperature, while cool and green roofs mostly provided cooling at heights above pedestrian level. However, cool pavements increased reflected sunlight from the ground to pedestrians at a set of unshaded receptor locations. This reflected radiation intensified the mean radiant temperature and consequently increased physiological equivalent temperature (PET) by 2.2 °C during the day, reducing the thermal comfort of pedestrians. At another set of receptor locations that were on average 5 m from roadways and underneath preexisting tree cover, cool pavements caused significant reductions in surface air temperatures and small changes in mean radiant temperature during the day, leading to decreases in PET of 1.1 °C, and consequent improvements in thermal comfort. For improving thermal comfort of pedestrians during the afternoon in unshaded locations, adding street trees was found to be the most effective strategy. However, afternoon thermal comfort improvements in already shaded locations adjacent to streets were most significant for cool pavements. Green and cool roofs showed the lowest impact on the thermal comfort of pedestrians since they modify the energy balance at roof level, above the height of pedestrians.

  13. Measurement of local high-level, transient surface heat flux

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.

    1988-01-01

    This study is part of a continuing investigation to develop methods for measuring local transient surface heat flux. A method is presented for simultaneous measurements of dual heat fluxes at a surface location by considering the heat flux as a separate function of heat stored and heat conducted within a heat flux gage. Surface heat flux information is obtained from transient temperature measurements taken at points within the gage. Heat flux was determined over a range of 4 to 22 MW/sq m. It was concluded that the method is feasible. Possible applications are for heat flux measurements on the turbine blade surfaces of space shuttle main engine turbopumps and on the component surfaces of rocket and advanced gas turbine engines and for testing sensors in heat flux gage calibrators.

  14. Convex optimization of MRI exposure for mitigation of RF-heating from active medical implants

    NASA Astrophysics Data System (ADS)

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2015-09-01

    Local RF-heating of elongated medical implants during magnetic resonance imaging (MRI) may pose a significant health risk to patients. The actual patient risk depends on various parameters including RF magnetic field strength and frequency, MR coil design, patient’s anatomy, posture, and imaging position, implant location, RF coupling efficiency of the implant, and the bio-physiological responses associated with the induced local heating. We present three constrained convex optimization strategies that incorporate the implant’s RF-heating characteristics, for the reduction of local heating of medical implants during MRI. The study emphasizes the complementary performances of the different formulations. The analysis demonstrates that RF-induced heating of elongated metallic medical implants can be carefully controlled and balanced against MRI quality. A reduction of heating of up to 25 dB can be achieved at the cost of reduced uniformity in the magnitude of the B1+ field of less than 5%. The current formulations incorporate a priori knowledge of clinically-specific parameters, which is assumed to be available. Before these techniques can be applied practically in the broader clinical context, further investigations are needed to determine whether reduced access to a priori knowledge regarding, e.g. the patient’s anatomy, implant routing, RF-transmitter, and RF-implant coupling, can be accepted within reasonable levels of uncertainty.

  15. Convex optimization of MRI exposure for mitigation of RF-heating from active medical implants.

    PubMed

    Córcoles, Juan; Zastrow, Earl; Kuster, Niels

    2015-09-21

    Local RF-heating of elongated medical implants during magnetic resonance imaging (MRI) may pose a significant health risk to patients. The actual patient risk depends on various parameters including RF magnetic field strength and frequency, MR coil design, patient's anatomy, posture, and imaging position, implant location, RF coupling efficiency of the implant, and the bio-physiological responses associated with the induced local heating. We present three constrained convex optimization strategies that incorporate the implant's RF-heating characteristics, for the reduction of local heating of medical implants during MRI. The study emphasizes the complementary performances of the different formulations. The analysis demonstrates that RF-induced heating of elongated metallic medical implants can be carefully controlled and balanced against MRI quality. A reduction of heating of up to 25 dB can be achieved at the cost of reduced uniformity in the magnitude of the B(1)(+) field of less than 5%. The current formulations incorporate a priori knowledge of clinically-specific parameters, which is assumed to be available. Before these techniques can be applied practically in the broader clinical context, further investigations are needed to determine whether reduced access to a priori knowledge regarding, e.g. the patient's anatomy, implant routing, RF-transmitter, and RF-implant coupling, can be accepted within reasonable levels of uncertainty. PMID:26350025

  16. Heat flow calorimeter. [measures output of Ni-Cd batteries

    NASA Technical Reports Server (NTRS)

    Fletcher, J. C.; Johnston, W. V. (Inventor)

    1974-01-01

    Heat flow calorimeter devices are used to measure heat liberated from or absorbed by an object. This device is capable of measuring the thermal output of sealed nickel-cadmium batteries or cells during charge-discharge cycles. An elongated metal heat conducting rod is coupled between the calorimeter vessel and a heat sink, thus providing the only heat exchange path from the calorimeter vessel itself.

  17. Best Practices in Grid Integration of Variable Wind Power: Summary of Recent US Case Study Results and Mitigation Measures

    SciTech Connect

    Smith, J. Charles; Parsons, Brian; Acker, Thomas; Milligan, Michael; Zavidil, Robert; Schuerger, Matthew; DeMeo, Edgar

    2010-01-22

    This paper will summarize results from a number of utility wind integration case studies conducted recently in the US, and outline a number of mitigation measures based on insights from those studies.

  18. CO2 emission mitigation by geothermal development - especially with geothermal heat pumps

    NASA Astrophysics Data System (ADS)

    Rybach, L.

    2009-04-01

    Geothermal technologies for power generation or direct use operate with little or no greenhouse gas emissions. Since no burning processes are involved they are low in CO2 emissions. Geothermal energy development has thus great CO2 emission reduction potential when substituting fossil sources of energy. Geothermal heat pumps (GHP) represent the fastest growing branch of geothermal technology; they use the ubiquitous shallow geothermal resource. GHPs are electricity consumers, nevertheless they can contribute to the fight against climatic warming. Such systems are now increasingly used for space heating, cooling, and to provide domestic hot water. With heat pump systems the use of fossil primary energy sources can be avoided, thus GHPs contribute to energy security: many countries must rely in their space heating systems on imported fossil fuels. The degree of dependence on these can be reduced. Since heat pumps are usually driven by electric components the origin of the electricity and the corresponding CO2 emission must be considered. A compilation shows that there are great differences in this respect from country to country. The same (=electricity need with CO2 emission consequences) applies to GHPs too. This means that by new geothermal heat pumps only additional CO2 emission can be avoided ("saving"), not a reduction of actual emissions. When GHPs are installed in refurbishment (to replace fossil-fueled systems) actual emission reduction can be achieved. Emission reduction is also evident when electric heater/cooler installations, driven by fossil-based electricity, are replaced by GHP systems. Numerical examples are presented about saving and reduction.

  19. New debris flow mitigation measures in southern Gansu, China: a case study of the Zhouqu Region

    NASA Astrophysics Data System (ADS)

    Xiong, Muqi; Meng, Xingmin; Li, Yajun

    2014-05-01

    A devastating debris flow occurred in Zhouqu of Gansu Province, China, on 8th August 2010, resulting in a catastrophic disaster, with 1463 people being perished. The debris flow valleys, as other numerous debris valleys in the mountainous region, had preventive engineering constructions, such as check dames, properly designed based on common engineering practices for safe guiding the town located right on the debris flow fan. However, failures of such preventive measures often cause even heavier disasters than those that have no human interactions, as the mitigations give a false safety impression. Given such a weird situation and in order to explore a much more effective disaster prevention strategy against debris flows in the mountainous region, this paper makes a comparative study based on two cases in the area of which one had preventive structures and one hasn't. The result shows that inappropriate mitigation measures that have commonly been applying in the disaster reduction practices in the region are of questionable. It is concluded that going with the nature and following with the natural rules are the best strategy for disaster reduction in the region. Key words: debris flow disasters, disaster reduction strategy, preventive measures

  20. Surge Pressure Mitigation in the Global Precipitation Measurement Mission Core Propulsion System

    NASA Technical Reports Server (NTRS)

    Scroggins, Ashley R.; Fiebig, Mark D.

    2014-01-01

    The Global Precipitation Measurement (GPM) mission is an international partnership between NASA and JAXA whose Core spacecraft performs cutting-edge measurements of rainfall and snowfall worldwide and unifies data gathered by a network of precipitation measurement satellites. The Core spacecraft's propulsion system is a blowdown monopropellant system with an initial hydrazine load of 545 kg in a single composite overwrapped propellant tank. At launch, the propulsion system contained propellant in the tank and manifold tubes upstream of the latch valves, with low-pressure helium gas in the manifold tubes downstream of the latch valves. The system had a relatively high beginning-of- life pressure and long downstream manifold lines; these factors created conditions that were conducive to high surge pressures. This paper discusses the GPM project's approach to surge mitigation in the propulsion system design. The paper describes the surge testing program and results, with discussions of specific difficulties encountered. Based on the results of surge testing and pressure drop analyses, a unique configuration of cavitating venturis was chosen to mitigate surge while minimizing pressure losses during thruster maneuvers. This paper concludes with a discussion of overall lessons learned with surge pressure testing for NASA Goddard spacecraft programs.

  1. Marine and Hydrokinetic Renewable Energy Devices, Potential Navigational Hazards and Mitigation Measures

    SciTech Connect

    Cool, Richard, M.; Hudon, Thomas, J.; Basco, David, R.; Rondorf, Neil, E.

    2009-12-01

    On April 15, 2008, the Department of Energy (DOE) issued a Funding Opportunity Announcement for Advanced Water Power Projects which included a Topic Area for Marine and Hydrokinetic Renewable Energy Market Acceleration Projects. Within this Topic Area, DOE identified potential navigational impacts of marine and hydrokinetic renewable energy technologies and measures to prevent adverse impacts on navigation as a sub-topic area. DOE defines marine and hydrokinetic technologies as those capable of utilizing one or more of the following resource categories for energy generation: ocean waves; tides or ocean currents; free flowing water in rivers or streams; and energy generation from the differentials in ocean temperature. PCCI was awarded Cooperative Agreement DE-FC36-08GO18177 from the DOE to identify the potential navigational impacts and mitigation measures for marine hydrokinetic technologies. A technical report addressing our findings is available on this Science and Technology Information site under the Product Title, "Marine and Hydrokinetic Renewable Energy Technologies: Potential Navigational Impacts and Mitigation Measures". This product is a brochure, primarily for project developers, that summarizes important issues in that more comprehensive report, identifies locations where that report can be downloaded, and identifies points of contact for more information.

  2. The costs and efficacy of sediment mitigation measures for representative farm types across England and Wales

    NASA Astrophysics Data System (ADS)

    Collins, A. L.; Zhang, Y.; Naden, P.

    2015-03-01

    A major collaborative research project in the UK is delivering new science to support improved targeting of on-farm pollution mitigation measures for the benefit of freshwater ecology. One important aspect of the project concerns a national scale evaluation of the costs and efficacy of packages of sediment mitigation measures which can be delivered over and above the existing implementation of abatement through various policy instruments including advice and new targeted agri-environment schemes. The assessment includes typical farm types present across England and Wales. Outputs from this assessment of costs and efficacy will eventually be used to help model the potential for closing the sediment pollution gap in those water bodies currently failing water quality targets due to sediment loss from agriculture. Some preliminary uncertainty ranges in costs (-£146,402 to £175,631) and effectiveness (0-80%) associated with a potential policy scenario implementing a large number (up to 93) of abatement measures at 95% uptake are presented in this paper.

  3. Field Measurements of Heating System Efficiency in Nine Electrically-Heated Manufactured Homes.

    SciTech Connect

    Davis, Bob; Siegel, J.; Palmiter, L.; Baylon, D.

    1996-07-01

    This report presents the results of field measurements of heating efficiency performed on nine manufactured homes sited in the Pacific Northwest. The testing procedure collects real-time data on heating system energy use and heating zone temperatures, allowing direct calculation of heating system efficiency.

  4. A new modelling framework and mitigation measures for increased resilience to flooding

    NASA Astrophysics Data System (ADS)

    Valyrakis, Manousos; Alexakis, Athanasios; Solley, Mark

    2015-04-01

    Flooding in rivers and estuaries is amongst the most significant challenges our society has yet to tackle effectively. Use of floodwall systems is one of the potential measures that can be used to mitigate the detrimental socio-economical and ecological impacts and alleviate the associated costs of flooding. This work demonstrates the utility of such systems for a case study via appropriate numerical simulations, in addition to conducting scaled flume experiments towards obtaining a better understanding of the performance and efficiency of the flood-wall systems. At first, the results of several characteristic inundation modeling scenarios and flood mitigation options, for a flood-prone region in Scotland. In particular, the history and hydrology of the area are discussed and the assumptions and hydraulic model input (model geometry including instream hydraulic structures -such as bridges and weirs- river and floodplain roughness, initial and boundary conditions) are presented, followed by the model results. Emphasis is given on the potential improvements brought about by mitigating flood risk using flood-wall systems. Further, the implementation of the floodwall in mitigating flood risk is demonstrated via appropriate numerical modeling, utilizing HEC-RAS to simulate the effect of a river's rising stage during a flood event, for a specific area. The later part of this work involves the design, building and utilization of a scaled physical model of a flood-wall system. These experiments are carried out at one of the research flumes in the Water Engineering laboratory of the University of Glasgow. These involve an experimental investigation where the increase of force applied on the floodwall is measured for different degrees of deflection of the water in the stream, under the maximum flow discharge that can be carried through without exceeding the floodwall height (and accounting for the effect of super-elevation). These results can be considered upon the

  5. Green and cool roofs to mitigate urban heat island effects in the Chicago metropolitan area: evaluation with a regional climate model

    NASA Astrophysics Data System (ADS)

    Sharma, A.; Conry, P.; Fernando, H. J. S.; Hamlet, Alan F.; Hellmann, J. J.; Chen, F.

    2016-06-01

    The effects of urban heat islands (UHIs) have a substantial bearing on the sustainability of cities and environs. This paper examines the efficacy of green and cool roofs as potential UHI mitigation strategies to make cities more resilient against UHI. We have employed the urbanized version of the Weather Research and Forecasting (uWRF) model at high (1 km) resolution with physically-based rooftop parameterization schemes (conventional, green and cool), a first-time application to the Chicago metropolitan area. We simulated a hot summer period (16–18 August 2013) and assessed (i) UHI reductions for different urban landuse with green/cool roofs, (ii) the interaction of lake breeze and UHI, and (iii) diurnal boundary layer dynamics. The performance of uWRF was evaluated using sensible heat flux and air temperature measurements from an urban mini-field campaign. The simulated roof surface energy balance captured the energy distribution with respective rooftop algorithms. Results showed that daytime roof temperature reduced and varied linearly with increasing green roof fractions, from less than 1 °C for the case of 25% green roof to ∼3 °C during peak daytime for 100% green roof. Diurnal transitions from land to lake breeze and vice versa had a substantial impact on the daytime cycle of roof surface UHI, which had a 3–4 hour lag in comparison to 2 m UHI. Green and cool roofs reduced horizontal and vertical wind speeds and affected lower atmosphere dynamics, including reduced vertical mixing, lower boundary layer depth, and weaker convective rolls. The lowered wind speeds and vertical mixing during daytime led to stagnation of air near the surface, potentially causing air quality issues. The selection of green and cool roofs for UHI mitigation should therefore carefully consider the competing feedbacks. The new results for regional land-lake circulations and boundary layer dynamics from this study may be extended to other urbanized areas, particularly to coastal

  6. Mitigating environmental impacts through the energetic use of wood: Regional displacement factors generated by means of substituting non-wood heating systems.

    PubMed

    Wolf, Christian; Klein, Daniel; Richter, Klaus; Weber-Blaschke, Gabriele

    2016-11-01

    Wood biomass, especially when applied for heating, plays an important role for mitigating environmental impacts such as climate change and the transition towards higher shares of renewable energy in today's energy mix. However, the magnitude of mitigation benefits and burdens associated with wood use can vary greatly depending on regional parameters such as the displaced fossil reference or heating mix. Therefore, regionalized displacement factors, considering region-specific production conditions and substituted products are required when assessing the precise contribution of wood biomass towards the mitigation of environmental impacts. We carried out Life Cycle Assessments of wood heating systems for typical Bavarian conditions and substitute energy carriers with a focus on climate change and particulate matter emissions. In order to showcase regional effects, we created weighted displacement factors for the region of Bavaria, based on installed capacities of individual wood heating systems and the harvested tree species distribution. The study reveals that GHG displacements between -57gCO2-eq.∗MJ(-1) of useful energy through the substitution of natural gas with a 15kW spruce pellets heating system and -165gCO2-eq.∗MJ(-1) through the substitution of power utilized for heating with a modern 6kW beech split log heating system can be achieved. It was shown that the GHG mitigation potentials of wood utilization are overestimated through the common use of light fuel oil as the only reference system. We further propose a methodology for the calculation of displacement factors which is adaptable to other regions worldwide. Based on our approach it is possible to generate displacement factors for wood heating systems which enable accurate decision-making for project planning in households, heating plants, communities and also for entire regions. PMID:27348704

  7. In Situ Mitigation of Subsurface and Peripheral Focused Ion Beam Damage via Simultaneous Pulsed Laser Heating.

    PubMed

    Stanford, Michael G; Lewis, Brett B; Iberi, Vighter; Fowlkes, Jason D; Tan, Shida; Livengood, Rick; Rack, Philip D

    2016-04-01

    Focused helium and neon ion (He(+)/Ne(+)) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of focused He(+)/Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) ion exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal energy which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposure process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. These results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via focused ion beams. PMID:26864147

  8. In situ mitigation of subsurface and peripheral focused ion beam damage via simultaneous pulsed laser heating

    DOE PAGESBeta

    Stanford, Michael G.; Lewis, Brett B.; Iberi, Vighter O.; Fowlkes, Jason Davidson; Tan, Shida; Livengood, Rick; Rack, Philip D.

    2016-02-16

    Focused helium and neon ion (He(+)/Ne(+) ) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of focused He(+) /Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) ion exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal energy which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposuremore » process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. In conclusion, these results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via focused ion beams.« less

  9. In situ mitigation of subsurface and peripheral focused ion beam damage via simultaneous pulsed laser heating

    SciTech Connect

    Stanford, Michael G.; Lewis, Brett B.; Iberi, Vighter O.; Fowlkes, Jason Davidson; Tan, Shida; Livengood, Rick; Rack, Philip D.

    2016-01-01

    Focused helium and neon ion (He(+)/Ne(+) ) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of focused He(+) /Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) ion exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal energy which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposure process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. In conclusion, these results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via focused ion beams.

  10. Measuring Furnace/Sample Heat-Transfer Coefficients

    NASA Technical Reports Server (NTRS)

    Rosch, William R.; Fripp, Archibald L., Jr.; Debnam, William J., Jr.; Woodell, Glenn A.

    1993-01-01

    Complicated, inexact calculations now unnecessary. Device called HTX used to simulate and measure transfer of heat between directional-solidification crystal-growth furnace and ampoule containing sample of crystalline to be grown. Yields measurement data used to calculate heat-transfer coefficients directly, without need for assumptions or prior knowledge of physical properties of furnace, furnace gas, or specimen. Determines not only total heat-transfer coefficients but also coefficients of transfer of heat in different modes.

  11. Analysis of the 2002 flood in Austria - facts, conclusions and mitigation measures

    NASA Astrophysics Data System (ADS)

    Formayer, H.; Habersack, H.; Holzmann, H.; Moser, A.; Seibert, P.

    2003-04-01

    In August 2002 Austria was affected - like other European countries e.g. Germany, Czech Republic or Romania - by an extreme flood event, which occurred in Central Europe and brought rainfall of extraordinary extent and flood recurrence intervals from several years to more than 1000 years. Losses of human life and livestock and damages of infrastructure, buildings, public and private properties rose the public awareness and the demand for improvement of future flood mitigation measures. The Centre of Natural Hazards and Risk Management of the BOKU-University for Natural Resources and Applied Life Sciences, Vienna startet as a first initiative with a summary and review of all reports and documents upon the regional impact of the event. The summary includes the description of the meteorological boundary conditions, the flood generation and their frequencies. A broad range of disciplinary aspects like river engineering, river ecology, vegetation and biology, soil science and soil mechanics, rural and urban planning were involved. The inventory and interpretation of the damages forms a base for assessment of shortcomings and requirements for a successful flood protection strategy for the future. The holistic approach will result in improved regional water management plans and assists in the development of a sustainable, catchment based flood mitigation strategy. Besides the review of the event the presentation will comment on some lacks and shortcomings in the collected data base and will give hints for future demands in online monitoring requirements, on establishment and improvement of forecasting tools and of the information transfer to the emergency services.

  12. Chemistry control and corrosion mitigation of heat transfer salts for the fluoride salt reactor (FHR)

    SciTech Connect

    Kelleher, B. C.; Sellers, S. R.; Anderson, M. H.; Sridharan, K.; Scheele, R. D.

    2012-07-01

    The Molten Salt Reactor Experiment (MSRE) was a prototype nuclear reactor which operated from 1965 to 1969 at Oak Ridge National Laboratory. The MSRE used liquid fluoride salts as a heat transfer fluid and solvent for fluoride based {sup 235}U and {sup 233}U fuel. Extensive research was performed in order to optimize the removal of oxide and metal impurities from the reactor's heat transfer salt, 2LiF-BeF{sub 2} (FLiBe). This was done by sparging a mixture of anhydrous hydrofluoric acid and hydrogen gas through the FLiBe at elevated temperatures. The hydrofluoric acid reacted with oxides and hydroxides, fluorinating them while simultaneously releasing water vapor. Metal impurities such as iron and chromium were reduced by hydrogen gas and filtered out of the salt. By removing these impurities, the corrosion of reactor components was minimized. The Univ. of Wisconsin - Madison is currently researching a new chemical purification process for fluoride salts that make use of a less dangerous cleaning gas, nitrogen trifluoride. Nitrogen trifluoride has been predicted as a superior fluorinating agent for fluoride salts. These purified salts will subsequently be used for static and loop corrosion tests on a variety of reactor materials to ensure materials compatibility for the new FHR designs. Demonstration of chemistry control methodologies along with potential reduction in corrosion is essential for the use of a fluoride salts in a next generator nuclear reactor system. (authors)

  13. Marine and Hydrokinetic Renewable Energy Technologies: Potential Navigational Impacts and Mitigation Measures

    SciTech Connect

    Cool, Richard, M.; Hudon, Thomas, J.; Basco, David, R.; Rondorf, Neil, E.

    2009-12-10

    On April 15, 2008, the Department of Energy (DOE) issued a Funding Opportunity Announcement for Advanced Water Power Projects which included a Topic Area for Marine and Hydrokinetic Renewable Energy Market Acceleration Projects. Within this Topic Area, DOE identified potential navigational impacts of marine and hydrokinetic renewable energy technologies and measures to prevent adverse impacts on navigation as a sub-topic area. DOE defines marine and hydrokinetic technologies as those capable of utilizing one or more of the following resource categories for energy generation: ocean waves; tides or ocean currents; free flowing water in rivers or streams; and energy generation from the differentials in ocean temperature. PCCI was awarded Cooperative Agreement DE-FC36-08GO18177 from the DOE to identify the potential navigational impacts and mitigation measures for marine hydrokinetic technologies, as summarized herein. The contract also required cooperation with the U.S. Coast Guard (USCG) and two recipients of awards (Pacific Energy Ventures and reVision) in a sub-topic area to develop a protocol to identify streamlined, best-siting practices. Over the period of this contract, PCCI and our sub-consultants, David Basco, Ph.D., and Neil Rondorf of Science Applications International Corporation, met with USCG headquarters personnel, with U.S. Army Corps of Engineers headquarters and regional personnel, with U.S. Navy regional personnel and other ocean users in order to develop an understanding of existing practices for the identification of navigational impacts that might occur during construction, operation, maintenance, and decommissioning. At these same meetings, “standard” and potential mitigation measures were discussed so that guidance could be prepared for project developers. Concurrently, PCCI reviewed navigation guidance published by the USCG and international community. This report summarizes the results of this effort, provides guidance in the form of a

  14. Investigation of the impact of climate change on river water temperature: possible mitigation measures using riparian vegetation

    NASA Astrophysics Data System (ADS)

    Weihs, Philipp; Trimmel, Heidelinde; Formayer, Herbert; Kalny, Gerda; Rauch, Hans Peter; Leidinger, David

    2016-04-01

    Water stream temperature is a relevant factor for water quality since it is an important driver of water oxygen content and in turn also reduces or increases stress on the aquatic fauna. The water temperature of streams is determined by the source and inflow water temperature, by the energy balance at the stream surface and by the hydrological regime of the stream. Main factors driving the energy balance of streams are radiation balance and air temperature which influence the sensitive and latent heat flux. The present study investigates the influence of climate change on water temperature of streams and the potential of riparian vegetation to mitigate its effects. Within the scope of the project BIO_CLIC routine measurements of water temperature at 33 locations alongside the rivers Pinka and Lafnitz were performed from spring 2012 until autumn 2014. In addition meteorological measurements of global shortwave and longwave radiation, air temperature, wind and air humidity were carried out during this time. For the same time period, data of discharge and water levels of both rivers were provided by the public hydrological office. This time period also includes the heat episode of summer 2013 during which the highest air temperature ever recorded in Austria was reported on 8 August at 40.5°C. In the lower reaches of the river Pinka, at the station Burg the monthly mean water temperature of August 2013 was with more than 22°C, 1°C higher than the mean water temperature of the same period of the previous years. At the same station, the maximum water temperature of 27.1°C was recorded on 29 July, 9 days prior to the air temperature record. Analysis shows that at the downstream stations the main driving parameter is solar radiation whereas at the upstream stations a better correlation between air temperature and water temperature is obtained. The influence of riparian vegetation on water temperature, leading to lower water temperature by shading, is also detectable

  15. A Survey of Measurement, Mitigation, and Verification Field Technologies for Carbon Sequestration Geologic Storage

    NASA Astrophysics Data System (ADS)

    Cohen, K. K.; Klara, S. M.; Srivastava, R. D.

    2004-12-01

    The U.S. Department of Energy's (U.S. DOE's) Carbon Sequestration Program is developing state-of-the-science technologies for measurement, mitigation, and verification (MM&V) in field operations of geologic sequestration. MM&V of geologic carbon sequestration operations will play an integral role in the pre-injection, injection, and post-injection phases of carbon capture and storage projects to reduce anthropogenic greenhouse gas emissions. Effective MM&V is critical to the success of CO2 storage projects and will be used by operators, regulators, and stakeholders to ensure safe and permanent storage of CO2. In the U.S. DOE's Program, Carbon sequestration MM&V has numerous instrumental roles: Measurement of a site's characteristics and capability for sequestration; Monitoring of the site to ensure the storage integrity; Verification that the CO2 is safely stored; and Protection of ecosystems. Other drivers for MM&V technology development include cost-effectiveness, measurement precision, and frequency of measurements required. As sequestration operations are implemented in the future, it is anticipated that measurements over long time periods and at different scales will be required; this will present a significant challenge. MM&V sequestration technologies generally utilize one of the following approaches: below ground measurements; surface/near-surface measurements; aerial and satellite imagery; and modeling/simulations. Advanced subsurface geophysical technologies will play a primary role for MM&V. It is likely that successful MM&V programs will incorporate multiple technologies including but not limited to: reservoir modeling and simulations; geophysical techniques (a wide variety of seismic methods, microgravity, electrical, and electromagnetic techniques); subsurface fluid movement monitoring methods such as injection of tracers, borehole and wellhead pressure sensors, and tiltmeters; surface/near surface methods such as soil gas monitoring and infrared

  16. The measurement of surface heat flux using the Peltier effect

    SciTech Connect

    Shewen, E.C. ); Hollands, K.G.T., Raithby, G.D. )

    1989-08-01

    Calorimetric methods for measuring surface heat flux use Joulean heating to keep the surface isothermal. This limits them to measuring the heat flux of surfaces that are hotter than their surroundings. Presented in this paper is a method whereby reversible Peltier effect heat transfer is used to maintain this isothermality, making it suitable for surfaces that are either hotter or colder than the surroundings. The paper outlines the theory for the method and describes physical models that have been constructed, calibrated, and tested. The tested physical models were found capable of measuring heat fluxes with an absolute accuracy of 1 percent over a wide range of temperature (5-50C) and heat flux (15-500 W/m{sup 2}), while maintaining isothermality to within 0.03 K. A drawback of the method is that it appears to be suited only for measuring the heat flux from thick metallic plates.

  17. Laser Measurement Of Convective-Heat-Transfer Coefficient

    NASA Technical Reports Server (NTRS)

    Porro, A. Robert; Hingst, Warren R.; Chriss, Randall M.; Seablom, Kirk D.; Keith, Theo G., Jr.

    1994-01-01

    Coefficient of convective transfer of heat at spot on surface of wind-tunnel model computed from measurements acquired by developmental laser-induced-heat-flux technique. Enables non-intrusive measurements of convective-heat-transfer coefficients at many points across surfaces of models in complicated, three-dimensional, high-speed flows. Measurement spot scanned across surface of model. Apparatus includes argon-ion laser, attenuator/beam splitter electronic shutter infrared camera, and subsystem.

  18. Multipath impact on ground-based global positioning system range measurements: Aspects of measurement, modeling, and mitigation

    NASA Astrophysics Data System (ADS)

    Bishop, G. J.; Holland, E. A.

    1994-07-01

    Multiple mechanisms propagation paths (multipath) can be the most important error source in ground-based Global Positioning System (GPS) measurement of range to the satellites. This multipath error, arising from a combination of the direct path and reflections from objects relatively close to the receiving antenna, can at times exceed the ionospheric delay error, which the two-frequency (1228 and 1575 MHz) GPS signal format is designed to measure and correct. GPS multipath can seriously degrade Differential GPS (DGPS) navigation, geodetic measurements, ionospheric monitoring, and other GPS applications, yet the source of the problem may not be evident without the use of specialized tests. Several techniques have been proposed to reduce the effects of GPS multipath; these include: improved receiver technology, specialized antenna designs, and various modeling or filtering approaches. This paper illustrates the nature of the two-frequency GPS multipath problem with measurement data from typical ground-based installations, exhibiting variation in multipath conditions, ranging from low to quite high for the varying geometries of the available satellite tracks. Leading mitigation techniques are reviewed, with emphasis on multipath modeling. A new simple modeling approach currently being studied by Phillips Laboratory is discussed. This technique takes advantage of the daily repetition of the GPS observation geometry from a ground station to create a 'multipath template' specific to each satellite pass, and reduce multipath effects on successive days. Data is presented showing significant improvement in a severe multipath environment and contrasting the effectiveness of this approach with all-sky modeling techniques. Mitigation techniques for GPS multipath show potential to enable GPS ground-based range and ionospheric measurement to greatly reduce errors at low elevation angles, leading to improved accuracy and wider coverage area capability.

  19. Upwellings mitigated Plio-Pleistocene heat stress for reef corals on the Florida platform (USA)

    NASA Astrophysics Data System (ADS)

    Brachert, T. C.; Reuter, M.; Krüger, S.; Kirkerowicz, J.; Klaus, J. S.

    2015-10-01

    The fast growing calcareous skeletons of zooxanthellate reef corals (z-corals) represent unique environmental proxy archives through their oxygen and carbon stable isotope composition (δ18O, δ13C). In addition, the accretion of the skeleton itself is ultimately linked to the environment and responds with variable growth rates (extension rate) and density to environmental changes. Here we present classical proxy data (δ18O, δ13C) in combination with calcification records from 15 massive z-corals. The z-corals were sampled from four interglacial units of the Florida carbonate platform (USA) dated approximately 3.2, 2.9, 1.8 and 1.2 Ma (middle Pliocene to early Pleistocene). The z-corals (Solenastrea, Orbicella, Porites) derive from unlithified shallow marine carbonates and were carefully screened for primary preservation suited for proxy analysis. We show that skeletal accretion was non-linear and responded with decreasing overall calcification rates (decreasing extension rate but increasing density) to warmer water temperatures. Under high annual water temperatures, inferred from subannually resolved δ18O data, skeletal bulk density was high, but extension rates and overall calcification rates were at a minimum (endmember scenario 1). Maximum skeletal density was reached during the summer season giving rise to a growth band of high density within the annually banded skeletons ("high density band", HDB). With low mean annual water temperatures (endmember scenario 2), bulk skeletal density was low but extension rates and calcification rates reached a maximum, and under these conditions the HDB formed during winter. Although surface water temperatures in the Western Atlantic warm pool during the interglacials of the late Neogene where ∼ 2 °C higher than they are in the present-day, intermittent upwelling of cool, nutrient rich water mitigated water temperatures off southwestern Florida in the middle of the Atlantic warm pool and created temporary refuges for

  20. Upwellings mitigated Plio-Pleistocene heat stress for reef corals on the Florida platform (USA)

    NASA Astrophysics Data System (ADS)

    Brachert, Thomas C.; Reuter, Markus; Krüger, Stefan; Kirkerowicz, Julia; Klaus, James S.

    2016-03-01

    The fast growing calcareous skeletons of zooxanthellate reef corals (z corals) represent unique environmental proxy archives through their oxygen and carbon stable isotope composition (δ18O, δ13C). In addition, the accretion of the skeleton itself is ultimately linked to the environment and responds with variable growth rates (extension rate) and density to environmental changes. Here we present classical proxy data (δ18O, δ13C) in combination with calcification records from 15 massive z corals. The z corals were sampled from four interglacial units of the Florida carbonate platform (USA) dated approximately 3.2, 2.9, 1.8 and 1.2 Ma (middle Pliocene to early Pleistocene). The z corals (Solenastrea, Orbicella, Porites) derive from unlithified shallow marine carbonates and were carefully screened for primary preservation suited for proxy analysis. We show that skeletal accretion responded with decreasing overall calcification rates (decreasing extension rate but increasing density) to warmer water temperatures. Under high annual water temperatures, inferred from sub-annually resolved δ18O data, skeletal bulk density was high, but extension rates and overall calcification rates were at a minimum (endmember scenario 1). Maximum skeletal density was reached during the summer season giving rise to a growth band of high density within the annually banded skeletons ("high density band", HDB). With low mean annual water temperatures (endmember scenario 2), bulk skeletal density was low but extension rates and calcification rates reached a maximum, and under these conditions the HDB formed during winter. Although surface water temperatures in the Western Atlantic warm pool during the interglacials of the late Neogene were ˜ 2 °C higher than they are in the present day, intermittent upwelling of cool, nutrient-rich water mitigated water temperatures off south-western Florida and created temporary refuges for z coral growth. Based on the sub-annually resolved δ18O and

  1. Mitigating systematic errors in angular correlation function measurements from wide field surveys

    NASA Astrophysics Data System (ADS)

    Morrison, C. B.; Hildebrandt, H.

    2015-12-01

    We present an investigation into the effects of survey systematics such as varying depth, point spread function size, and extinction on the galaxy selection and correlation in photometric, multi-epoch, wide area surveys. We take the Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS) as an example. Variations in galaxy selection due to systematics are found to cause density fluctuations of up to 10 per cent for some small fraction of the area for most galaxy redshift slices and as much as 50 per cent for some extreme cases of faint high-redshift samples. This results in correlations of galaxies against survey systematics of order ˜1 per cent when averaged over the survey area. We present an empirical method for mitigating these systematic correlations from measurements of angular correlation functions using weighted random points. These weighted random catalogues are estimated from the observed galaxy overdensities by mapping these to survey parameters. We are able to model and mitigate the effect of systematic correlations allowing for non-linear dependences of density on systematics. Applied to CFHTLenS, we find that the method reduces spurious correlations in the data by a factor of 2 for most galaxy samples and as much as an order of magnitude in others. Such a treatment is particularly important for an unbiased estimation of very small correlation signals, as e.g. from weak gravitational lensing magnification bias. We impose a criterion for using a galaxy sample in a magnification measurement of the majority of the systematic correlations show improvement and are less than 10 per cent of the expected magnification signal when combined in the galaxy cross-correlation. After correction the galaxy samples in CFHTLenS satisfy this criterion for zphot < 0.9 and will be used in a future analysis of magnification.

  2. Heat flux microsensor measurements and calibrations

    NASA Technical Reports Server (NTRS)

    Terrell, James P.; Hager, Jon M.; Onishi, Shinzo; Diller, Thomas E.

    1992-01-01

    A new thin-film heat flux gage has been fabricated specifically for severe high temperature operation using platinum and platinum-10 percent rhodium for the thermocouple elements. Radiation calibrations of this gage were performed at the AEDC facility over the available heat flux range (approx. 1.0 - 1,000 W/cu cm). The gage output was linear with heat flux with a slight increase in sensitivity with increasing surface temperature. Survivability of gages was demonstrated in quench tests from 500 C into liquid nitrogen. Successful operation of gages to surface temperatures of 750 C has been achieved. No additional cooling of the gages is required because the gages are always at the same temperature as the substrate material. A video of oxyacetylene flame tests with real-time heat flux and temperature output is available.

  3. Non-contact heat flux measurement using a transparent sensor

    NASA Technical Reports Server (NTRS)

    Ng, Daniel; Spuckler, Charles M.

    1993-01-01

    A working non-contact heat flux sensor was demonstrated using a transparent material (sapphire) and a multiwavelength pyrometer. The pyrometer is used to measure the temperatures of the two surfaces of the sensor from the spectrum of radiation originating from them. The heat conducted through the material is determined from the temperature difference of the two surfaces and the thermal conductivity of the material. The measured heat flux is equal to the incident heat flux within experimental error indicating that no calibration would be necessary. A steady state heat flux of 100 kW/sq m was easily achieved.

  4. Mitigation of the impact of terrestrial contamination on organic measurements from the Mars Science Laboratory.

    PubMed

    ten Kate, Inge L; Canham, John S; Conrad, Pamela G; Errigo, Therese; Katz, Ira; Mahaffy, Paul R

    2008-06-01

    The objective of the 2009 Mars Science Laboratory (MSL), which is planned to follow the Mars Exploration Rovers and the Phoenix lander to the surface of Mars, is to explore and assess quantitatively a site on Mars as a potential habitat for present or past life. Specific goals include an assessment of the past or present biological potential of the target environment and a characterization of its geology and geochemistry. Included in the 10 investigations of the MSL rover is the Sample Analysis at Mars (SAM) instrument suite, which is designed to obtain trace organic measurements, measure water and other volatiles, and measure several light isotopes with experiment sequences designed for both atmospheric and solid-phase samples. SAM integrates a gas chromatograph, a mass spectrometer, and a tunable laser spectrometer supported by sample manipulation tools both within and external to the suite. The sub-part-per-billion sensitivity of the suite for trace species, particularly organic molecules, along with a mobile platform that will contain many kilograms of organic materials, presents a considerable challenge due to the potential for terrestrial contamination to mask the signal of martian organics. We describe the effort presently underway to understand and mitigate, wherever possible within the resource constraints of the mission, terrestrial contamination in MSL and SAM measurements. PMID:18558810

  5. Mitigation of upward and downward vertical displacement event heat loads with upper or lower massive gas injection in DIII-D

    DOE PAGESBeta

    Hollmann, E. M.; Commaux, Nicolas J. C.; Eidietis, N. W.; Lasnier, C. J.; Moyer, R. A.; Parks, P. B.; Shiraki, Daisuke

    2015-10-12

    Intentionally triggered upward and downward vertical displacement events (VDEs) leading to disruptions were pre-emptively mitigated with neon massive gas injection (MGI) coming from either above or below the plasma. Global indicators of disruption mitigation effectiveness (conducted heat loads, radiated power, and vessel motion) do not show a clear improvement when mitigating with the gas jet located closer to the VDE impact area. A clear trend of improved mitigation is observed for earlier MGI timing relative to the VDE impact time. The plasma edge magnetic perturbation is seen to lock to a preferential phase during the VDE thermal quench, but thismore » phase is not clearly matched by preliminary attempts to fit to the conducted heat load phase. Clear indications of plasma infra-red (IR) emission are observed both before and during the disruptions. Furthermore, this IR emission can affect calculation of disruption heat loads; here, the time decay of post-disruption IR signals is used to correct for this effect.« less

  6. Nanomanufacturing concerns about measurements made in the SEM part IV: charging and its mitigation

    NASA Astrophysics Data System (ADS)

    Postek, Michael T.; Vladár, András. E.

    2015-08-01

    This is the fourth part of a series of tutorial papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST and other research institutions. Scanned particle beam instruments especially the scanning electron microscope (SEM) have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, the ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the apparent need for extensive operator training. Unfortunately, this has led to the idea that the SEM is just another expensive "digital camera" or another peripheral device connected to a computer and that all of the problems in obtaining good quality images and data have been solved. Hence, one using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and believing that, everything one sees on the micrograph is always correct. But, as described in this and the earlier papers, this may not be the case. Care must always be taken when reliable quantitative data are being sought. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modeling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper has discussed another major issue confronting the microscopist: specimen contamination and methods to eliminate it. The third paper discussed mechanical vibration and stage drift and some useful solutions to mitigate the problems caused by them, and here, in this the fourth contribution, the issues related to specimen "charging" and its mitigation are discussed relative

  7. Atmospheric particulate mercury in the megacity Beijing: Efficiency of mitigation measures and assessment of health effects

    NASA Astrophysics Data System (ADS)

    Schleicher, N. J.; Schäfer, J.; Chen, Y.; Blanc, G.; Chen, Y.; Chai, F.; Cen, K.; Norra, S.

    2016-01-01

    Atmospheric particulate mercury (HgP) was studied before, during, and after the Olympic Summer Games in Beijing, China, in August 2008 in order to investigate the efficiency of the emission control measures implemented by the Chinese Government. These source control measures comprised traffic reductions, increase in public transportation, planting of vegetation, establishment of parks, building freeze at construction sites, cleaner production techniques for industries and industry closures in Beijing and also in the surrounding areas. Strictest measures including the "odd-even ban" to halve the vehicle volume were enforced from the 20th of July to the 20th of September 2008. The Olympic period provided the unique opportunity to investigate the efficiency of these comprehensive actions implemented in order to reduce air pollution on a large scale. Therefore, the sampling period covered summer (August, September) and winter (December and January) samples over several years from December 2005 to September 2013. Average HgP concentrations in total suspended particulates (TSP) sampled in August 2008 were 81 ± 39 pg/m3 while TSP mass concentrations were 93 ± 49 μg/m3. This equals a reduction by about 63% for TSP mass and 65% for HgP, respectively, compared to the previous two years demonstrating the short-term success of the measures. However, after the Olympic Games, HgP concentrations increased again to pre-Olympic levels in August 2009 while values in August 2010 decreased again by 30%. Moreover, winter samples, which were 2- to 11-fold higher than corresponding August values, showed decreasing concentrations over the years indicating a long-term improvement of HgP pollution in Beijing. However, regarding adverse health effects, comparisons with soil guideline values and studies from other cities highlighted that HgP concentrations in TSP remained high in Beijing despite respective control measures. Consequently, future mitigation measures need to be tailored more

  8. Heat flux measurements on ceramics with thin film thermocouples

    NASA Technical Reports Server (NTRS)

    Holanda, Raymond; Anderson, Robert C.; Liebert, Curt H.

    1993-01-01

    Two methods were devised to measure heat flux through a thick ceramic using thin film thermocouples. The thermocouples were deposited on the front and back face of a flat ceramic substrate. The heat flux was applied to the front surface of the ceramic using an arc lamp Heat Flux Calibration Facility. Silicon nitride and mullite ceramics were used; two thicknesses of each material was tested, with ceramic temperatures to 1500 C. Heat flux ranged from 0.05-2.5 MW/m2(sup 2). One method for heat flux determination used an approximation technique to calculate instantaneous values of heat flux vs time; the other method used an extrapolation technique to determine the steady state heat flux from a record of transient data. Neither method measures heat flux in real time but the techniques may easily be adapted for quasi-real time measurement. In cases where a significant portion of the transient heat flux data is available, the calculated transient heat flux is seen to approach the extrapolated steady state heat flux value as expected.

  9. Using a cold radiometer to measure heat loads and survey heat leaks

    SciTech Connect

    DiPirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2014-01-29

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  10. Using a Cold Radiometer to Measure Heat Loads and Survey Heat Leaks

    NASA Technical Reports Server (NTRS)

    DiPirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2013-01-01

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  11. Using a Cold Radiometer to Measure Heat Loads and Survey Heat Leaks

    NASA Technical Reports Server (NTRS)

    Dipirro, M.; Tuttle, J.; Hait, T.; Shirron, P.

    2014-01-01

    We have developed an inexpensive cold radiometer for use in thermal/vacuum chambers to measure heat loads, characterize emissivity and specularity of surfaces and to survey areas to evaluate stray heat loads. We report here the results of two such tests for the James Webb Space Telescope to measure heat loads and effective emissivities of 2 major pieces of optical ground support equipment that will be used in upcoming thermal vacuum testing of the Telescope.

  12. An optimization model for regional air pollutants mitigation based on the economic structure adjustment and multiple measures: A case study in Urumqi city, China.

    PubMed

    Sun, Xiaowei; Li, Wei; Xie, Yulei; Huang, Guohe; Dong, Changjuan; Yin, Jianguang

    2016-11-01

    A model based on economic structure adjustment and pollutants mitigation was proposed and applied in Urumqi. Best-worst case analysis and scenarios analysis were performed in the model to guarantee the parameters accuracy, and to analyze the effect of changes of emission reduction styles. Results indicated that pollutant-mitigations of electric power industry, iron and steel industry, and traffic relied mainly on technological transformation measures, engineering transformation measures and structure emission reduction measures, respectively; Pollutant-mitigations of cement industry relied mainly on structure emission reduction measures and technological transformation measures; Pollutant-mitigations of thermal industry relied mainly on the four mitigation measures. They also indicated that structure emission reduction was a better measure for pollutants mitigation of Urumqi. Iron and steel industry contributed greatly in SO2, NOx and PM (particulate matters) emission reduction and should be given special attention in pollutants emission reduction. In addition, the scales of iron and steel industry should be reduced with the decrease of SO2 mitigation amounts. The scales of traffic and electric power industry should be reduced with the decrease of NOx mitigation amounts, and the scales of cement industry and iron and steel industry should be reduced with the decrease of PM mitigation amounts. The study can provide references of pollutants mitigation schemes to decision-makers for regional economic and environmental development in the 12th Five-Year Plan on National Economic and Social Development of Urumqi. PMID:27454097

  13. Heat flux measurement in SSME turbine blade tester

    SciTech Connect

    Liebert, C.H.

    1990-11-01

    Surface heat flux values were measured in the turbine blade thermal cycling tester located at NASA-Marshall. This is the first time heat flux has been measured in a space shuttle main engine turbopump environment. Plots of transient and quasi-steady state heat flux data over a range of about 0 to 15 MW/sq m are presented. Data were obtained with a miniature heat flux gage device developed at NASA-Lewis. The results from these tests are being incorporated into turbine design models. Also, these gages are being considered for airfoil surface heat flux measurement on turbine vanes mounted in SSME turbopump test bed engine nozzles at Marshall. Heat flux effects that might be observed on degraded vanes are discussed.

  14. Dissolved organic carbon interferences in UV nitrate measurements and possible mitigation methods

    NASA Astrophysics Data System (ADS)

    Thomas, R. G.; Foster, C. R.; Cohen, M. J.; Martin, J. B.; Delfino, J. J.

    2010-12-01

    .50, and 1.00 mg/L NO3. Each DOC dilution and standard was measured for 5 minutes. At concentrations above 10 mg/L, the error associated with the measurements was > 15%. Below that concentration the error was 5%. Analysis of the spectral data of this experiment and from the study site indicate that significant attenuation at UV wavelengths causes most of the loss of the nitrate signal and error. It is thus critical that the DOC be removed or deactivated as part of the in situ UV-based nitrate analysis. While this attenuation could be overcome by shortening the path length of the light beam, a shortened pathlength would also reduce sensitivity. To remove the DOC interference, we have constructed a UV photoreactor by winding 7 m of PTFE tubing around a quartz tube. The assembly was wrapped in reflective aluminum foil. A low-pressure UV lamp (10 Watts output, 95% emitted at the mercury resonance wavelength of 254 nm) was placed inside the quartz tube. This method should mitigate interferences caused by DOC. The extent of mitigation is currently being determined and will be described in the presentation.

  15. Can supine recovery mitigate the exercise intensity dependent attenuation of post-exercise heat loss responses?

    PubMed

    Kenny, Glen P; Gagnon, Daniel; Jay, Ollie; McInnis, Natalie H; Journeay, W Shane; Reardon, Francis D

    2008-08-01

    Cutaneous vascular conductance (CVC) and sweat rate are subject to non-thermal baroreflex-mediated attenuation post-exercise. Various recovery modalities have been effective in attenuating these decreases in CVC and sweat rate post-exercise. However, the interaction of recovery posture and preceding exercise intensity on post-exercise thermoregulation remains unresolved. We evaluated the combined effect of supine recovery and exercise intensity on post-exercise cardiovascular and thermal responses relative to an upright seated posture. Seven females performed 15 min of cycling ergometry at low- (LIE, 55% maximal oxygen consumption) or high-(HIE, 85% maximal oxygen consumption) intensity followed by 60 min of recovery in either an upright seated or supine posture. Esophageal temperature, CVC, sweat rate, cardiac output, stroke volume, heart rate, total peripheral resistance, and mean arterial pressure (MAP) were measured at baseline, at end-exercise, and at 2, 5, 12, 20, and every 10 min thereafter until the end of recovery. MAP and stroke volume were maintained during supine recovery to a greater extent relative to an upright seated recovery following HIE (p

  16. Counter-measures to mitigate residual- g effects on microgravity experiments on the space station

    NASA Astrophysics Data System (ADS)

    Monti, R.; Paterna, D.; Savino, R.

    2002-02-01

    The paper wants to approach the problem of the disturbances mitigation on the International Space Station (ISS) from a purely scientific view point by evaluating and trying to minimize the effects (fluid-dynamic disturbances) more than trying to minimize some of the causes (as achieved by Isolation Mounts). A study case, consisting in a cylindrical test cell filled with a silicone oil in presence of a temperature difference Δ T, has been identified to reproduce the ISS microgravity environment (when in presence of a steady residual- g) on ground by properly changing the fluid properties, the dimensions and the imposed temperature difference. The orientation of the cell with respect to the vertical direction has been changed using an appropriate device that corresponds, in the MGE, to different angles between the cell axis and the residual- g. The maximum distortion of the temperature field has been evaluated numerically and experimentally by measuring the maximum temperature difference, in the mid-cross-section, between points that would exhibit the very same temperature in a purely diffusive, quiescent state. Further experimental tests have been performed, using a different configuration, to measure the surface temperature distribution with an infrared thermocamera. The correlation between experimental and numerical results are in good agreement and the results indicate that the experiment facility can be properly oriented to minimize the convection disturbances. Another experiment for the study of the temperature/concentration distortions induced by residual- g and g-jitter during experiments on diffusion/thermodiffusion is proposed.

  17. Heat Transfer Salts for Nuclear Reactor Systems - Chemistry Control, Corrosion Mitigation, and Modeling

    SciTech Connect

    Anderson, Mark; Sridharan, Kumar; Morgan, Dane; Peterson, Per; Calderoni, Pattrick; Scheele, Randall; Casekka, Andrew; McNamara, Bruce

    2015-01-22

    The concept of a molten salt reactor has existed for nearly sixty years. Previously all work was done during a large collaborative effort at Oak Ridge National Laboratory, culminating in a research reactor which operated for 15,000 hours without major error. This technical success has garnished interest in modern, high temperature, reactor schemes. Research using molten fluoride salts for nuclear applications requires a steady supply of high grade molten salts. There is no bulk supplier of research grade fluoride salts in the world, so a facility which could provide all the salt needed for testing at the University of Wisconsin had to be produced. Two salt purification devices were made for this purpose, a large scale purifier, and a small scale purifier, each designed to clean the salts from impurities and reduce their corrosion potential. As of now, the small scale has performed with flibe salt, hydrogen, and hydrogen fluoride, yielding clean salt. This salt is currently being used in corrosion testing facilities at the Massachusetts Institute of Technology and the University of Wisconsin. Working with the beryllium based salts requires extensive safety measures and health monitoring to prevent the development of acute or chronic beryllium disease, two pulmonary diseases created by an allergic reaction to beryllium in the lungs. Extensive health monitoring, engineering controls, and environment monitoring had to be set up with the University of Wisconsin department of Environment, Health and Safety. The hydrogen fluoride required for purification was also an extreme health hazard requiring thoughtful planning and execution. These dangers have made research a slow and tedious process. Simple processes, such as chemical handling and clean-up, can take large amounts of ingenuity and time. Other work has complemented the experimental research at Wisconsin to advance high temperature reactor goals. Modeling work has been performed in house to re

  18. Measuring important parameters for air-sea heat exchange

    NASA Astrophysics Data System (ADS)

    Garbe, Christoph; Schimpf, Uwe; Jaehne, Bernd

    2002-03-01

    The heat transfer between the ocean and the atmosphere is one of the most important parameters governing the global climate. Important parameters include the heat transfer velocity and the net heat flux as well as parameters of the underlying transport model. However, the net heat flux is hard to measure since processes take place in the thermal boundary layer, that is the topmost layer of the ocean less than 1 mm thick. Current techniques rely on three independent measurements of the constituent fluxes, the sensible heat flux, latent heat flux and radiative flux. They depend on indirect measurements of meteorological parameters and rely on a combination of data from different sensors using a number of heuristic assumptions. High relative errors and the need for long temporal averaging reduce the practicability of these techniques. In this paper a novel technique is presented that circumvents these drawbacks by directly measuring the net heat flux across the air-water interface with a single low-NETD infrared camera. A newly developed digital image processing technique allows to simultaneously estimating the surface velocity field and parameters of the temporal temperature change. In particular, this technique allows estimating the total derivative of the temperature with respect to time from a sequence of infrared images, together with error bounds on the estimates. This derivative can be used to compute the heat flux density and the heat transfer velocity, as well as the probability density function of the underlying surface renewal model. It is also possible to estimate the bulk-skin temperature difference given rise to by the net heat flux. Our technique has been successfully used in both laboratory measurements in the Heidelberg Aeolotron, as well as in field measurements in the equatorial pacific during the NOAA GasExII experiment this spring. The data show that heat flux measurements to an accuracy of better than 5% on a time scale of seconds are feasible.

  19. Long term performance of radon mitigation systems

    SciTech Connect

    Prill, R.; Fisk, W.J.

    2002-03-01

    Researchers installed radon mitigation systems in 12 houses in Spokane, Washington and Coeur d'Alene, Idaho during the heating season 1985--1986 and continued to monitor indoor radon quarterly and annually for ten years. The mitigation systems included active sub-slab ventilation, basement over-pressurization, and crawlspace isolation and ventilation. The occupants reported various operational problems with these early mitigation systems. The long-term radon measurements were essential to track the effectiveness of the mitigation systems over time. All 12 homes were visited during the second year of the study, while a second set 5 homes was visited during the fifth year to determine the cause(s) of increased radon in the homes. During these visits, the mitigation systems were inspected and measurements of system performance were made. Maintenance and modifications were performed to improve system performance in these homes.

  20. Monticello BWR spent fuel assembly decay heat predictions and measurements

    SciTech Connect

    McKinnon, M.A.; Doman, J.W.; Heeb, C.M.; Creer, J.M.

    1986-06-01

    This report compares pre-calorimetry predictions of rates of six 7 x 7 boiling water reactor (BWR) spent fuel assemblies with measured decay heat rates. The assemblies were from Northern States Power Company's Monticello Nuclear Generating Plant and had burnups of 9 to 21 GWd/MTU and cooling times of 9 to 10 years. Conclusions are: The agreement between ORIGEN2 predictions and decay heat measurements of Monticello spent fuel is dependent on the method used to calibrate the calorimeter and to make the decay heat measurements. The agreement between predictions and measurements of decay heat rates of Monticello fuel is the same as that for Cooper and Dresden fuel if the same measurement method is used. The predictions are within a standard deviation of +-15 W of the measurements. Using a different measurement method, ORIGEN2 underpredicts the measured decay heat output of Monticello fuel assemblies by a constant 20 +- 2 W. The 20-W offset appears to be an artifact of the calibration procedure. The constant term in the calibration curve (i.e., q/sub DH/ = mx + b) can account for measurement differences of 40 W based on the 1983, 1984, and 1985 calibration curves. The difference between ORIGEN2 predictions and calorimeter decay heat measurements does not appear to be dependent on the magnitude of decay heat output. Predicted axial decay heat profiles are in good agreement with measured axial gamma radiation profiles. Recommendations are: Predictions using other decay heat codes should be compared to experimental data contained in this report, to evaluate prediction capabilities. The source of the differences that exist among calorimeter calibration curves needs to be determined. Calorimeter operational methods need to be investigated further to determine cause and effect relationships between operational method and calorimeter precision and accuracy.

  1. UNDERSTANDING METHANE EMISSIONS SOURCES AND VIABLE MITIGATION MEASURES IN THE NATURAL GAS TRANSMISSION SYSTEMS: RUSSIAN AND U.S. EXPERIENCE

    SciTech Connect

    Ishkov, A.; Akopova, Gretta; Evans, Meredydd; Yulkin, Grigory; Roshchanka, Volha; Waltzer, Suzie; Romanov, K.; Picard, David; Stepanenko, O.; Neretin, D.

    2011-10-01

    This article will compare the natural gas transmission systems in the U.S. and Russia and review experience with methane mitigation technologies in the two countries. Russia and the United States (U.S.) are the world's largest consumers and producers of natural gas, and consequently, have some of the largest natural gas infrastructure. This paper compares the natural gas transmission systems in Russia and the U.S., their methane emissions and experiences in implementing methane mitigation technologies. Given the scale of the two systems, many international oil and natural gas companies have expressed interest in better understanding the methane emission volumes and trends as well as the methane mitigation options. This paper compares the two transmission systems and documents experiences in Russia and the U.S. in implementing technologies and programs for methane mitigation. The systems are inherently different. For instance, while the U.S. natural gas transmission system is represented by many companies, which operate pipelines with various characteristics, in Russia predominately one company, Gazprom, operates the gas transmission system. However, companies in both countries found that reducing methane emissions can be feasible and profitable. Examples of technologies in use include replacing wet seals with dry seals, implementing Directed Inspection and Maintenance (DI&M) programs, performing pipeline pump-down, applying composite wrap for non-leaking pipeline defects and installing low-bleed pneumatics. The research methodology for this paper involved a review of information on methane emissions trends and mitigation measures, analytical and statistical data collection; accumulation and analysis of operational data on compressor seals and other emission sources; and analysis of technologies used in both countries to mitigate methane emissions in the transmission sector. Operators of natural gas transmission systems have many options to reduce natural gas losses

  2. Mitigation measures to reduce losses of phosphorus during the non-cropping period - a northern European perspective

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Degradation of natural waters by phosphorus (P) due to agricultural activities has been a problem in several countries for many years. Accordingly, mitigation measures to minimize this issue have been developed and used with varying success. Non-point source P from agricultural fields is one of the ...

  3. Divertor Heat Flux Mitigation in High-Performance H-mode Plasmas in the National Spherical Torus Experiment.

    SciTech Connect

    Soukhanovskii, V A; Maingi, R; Gates, D; Menard, J; Paul, S F; Raman, R; Roquemore, A L; Bell, R E; Bush, C; Kaita, R

    2008-09-22

    Experiments conducted in high-performance 1.0-1.2 MA 6 MW NBI-heated H-mode plasmas with a high flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high {beta}{sub p} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the lower single null configuration with higher-end elongation 2.2-2.4 and triangularity 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m{sup 2} to 0.5-2 MW/m{sup 2} in ELMy H-mode discharges using high magnetic flux expansion and partial detachment of the outer strike point at several D{sub 2} injection rates, while good core confinement and pedestal characteristics were maintained. The partially detached divertor regime was characterized by a 30-60% increase in divertor plasma radiation, a peak heat flux reduction by up to 70%, measured in a 10 cm radial zone, a five-fold increase in divertor neutral pressure, and a significant volume recombination rate increase.

  4. Assessment of diagnostic measurements for selection for residential radon mitigation. Rept. for Oct 87-Jan 88

    SciTech Connect

    Scott, A.G.; Sanchex, D.C.

    1992-01-01

    The paper discusses and critiques EPA's experience in conducting house evaluation visits in Florida and Ohio. Suggestions are offered as to the utility and priority to be given to selected diagnostic procedures and measurements. EPA has an experimental program to develop and demonstrate cost effective radon mitigation techniques. Most of the work is carried out in occupied houses with elevated radon concentrations. The study house selection process starts with monitoring surveys that establish an area as one with elevated radon concentrations in houses. Radon detectors are usually distributed with a questionnaire, which requests information on location (at least the ZIP Code level) and some indication of building style in addition to radon concentration. The survey identifies problem areas and housing types of the greatest experimental interest. If the pool of candidate houses is larger than the number that can be worked on, as is usually the case, then house evaluation visits to the candidate houses are conducted in order to provide the information needed to make a selection of study houses from among the candidates.

  5. Assessment of environmental impact on air quality by cement industry and mitigating measures: a case study.

    PubMed

    Kabir, G; Madugu, A I

    2010-01-01

    In this study, environmental impact on air quality was evaluated for a typical Cement Industry in Nigeria. The air pollutants in the atmosphere around the cement plant and neighbouring settlements were determined using appropriate sampling techniques. Atmospheric dust and CO2 were prevalent pollutants during the sampling period; their concentrations were recorded to be in the range of 249-3,745 mg/m3 and 2,440-2,600 mg/m3, respectively. Besides atmospheric dust and CO2, the air pollutants such as NOx, SOx and CO were in trace concentrations, below the safe limits approved by FEPA that are 0.0062-0.093 mg/m3 NOx, 0.026 mg/m3 SOx and 114.3 mg/m3 CO, respectively. Some cost-effective mitigating measures were recommended that include the utilisation of readily available and low-cost pozzolans material to produce blended cement, not only could energy efficiency be improved, but carbon dioxide emission could also be minimised during clinker production; and the installation of an advance high-pressure grinding rolls (clinker-roller-press process) to maximise energy efficiency to above what is obtainable from the traditional ball mills and to minimise CO2 emission from the power plant. PMID:19067202

  6. Voluntary suppression of hyperthermia-induced hyperventilation mitigates the reduction in cerebral blood flow velocity during exercise in the heat.

    PubMed

    Tsuji, Bun; Honda, Yasushi; Ikebe, Yusuke; Fujii, Naoto; Kondo, Narihiko; Nishiyasu, Takeshi

    2015-04-15

    Hyperthermia during prolonged exercise leads to hyperventilation, which can reduce arterial CO2 pressure (PaCO2 ) and, in turn, cerebral blood flow (CBF) and thermoregulatory response. We investigated 1) whether humans can voluntarily suppress hyperthermic hyperventilation during prolonged exercise and 2) the effects of voluntary breathing control on PaCO2 , CBF, sweating, and skin blood flow. Twelve male subjects performed two exercise trials at 50% of peak oxygen uptake in the heat (37°C, 50% relative humidity) for up to 60 min. Throughout the exercise, subjects breathed normally (normal-breathing trial) or they tried to control their minute ventilation (respiratory frequency was timed with a metronome, and target tidal volumes were displayed on a monitor) to the level reached after 5 min of exercise (controlled-breathing trial). Plotting ventilatory and cerebrovascular responses against esophageal temperature (Tes) showed that minute ventilation increased linearly with rising Tes during normal breathing, whereas controlled breathing attenuated the increased ventilation (increase in minute ventilation from the onset of controlled breathing: 7.4 vs. 1.6 l/min at +1.1°C Tes; P < 0.001). Normal breathing led to decreases in estimated PaCO2 and middle cerebral artery blood flow velocity (MCAV) with rising Tes, but controlled breathing attenuated those reductions (estimated PaCO2 -3.4 vs. -0.8 mmHg; MCAV -10.4 vs. -3.9 cm/s at +1.1°C Tes; P = 0.002 and 0.011, respectively). Controlled breathing had no significant effect on chest sweating or forearm vascular conductance (P = 0.67 and 0.91, respectively). Our results indicate that humans can voluntarily suppress hyperthermic hyperventilation during prolonged exercise, and this suppression mitigates changes in PaCO2 and CBF. PMID:25632021

  7. Risk mitigation measures for diffuse pesticide entry into aquatic ecosystems: proposal of a guide to identify appropriate measures on a catchment scale.

    PubMed

    Bereswill, Renja; Streloke, Martin; Schulz, Ralf

    2014-04-01

    Measures to mitigate the risk of pesticide entry into aquatic ecosystems are becoming increasingly more important in the management of hot spots of pesticide transfer; such management, for example, is required by the European Union's directive for the sustainable use of pesticides (2009/128/EC). Measures beyond those currently stipulated for pesticide product authorization may be needed. A concise compilation of the appropriate measures for users (that are primarily farmers but also, e.g., regulators and farm extension services) and a guide for practically identifying these measures at the catchment scale is currently not available. Therefore, a proposal was developed for a guide focusing on the most important diffuse entry pathways (spray drift and runoff). Based on a survey of exposure-relevant landscape parameters (i.e., the riparian buffer strip width, riparian vegetation type, density of ground vegetation cover, coverage of the water body with aquatic macrophytes, field slope, and existence of concentrated flow paths), a set of risk mitigation measures focusing on the specific situation of pollution of a water body catchment can be identified. The user can then choose risk mitigation measures to implement, assisted by evaluations of their efficiency in reducing pesticide entry, feasibility, and expected acceptability to farmers. Currently, 12 landscape-related measures and 6 application-related measures are included. The present guide presents a step toward the practical implementation of risk mitigation measures for reducing pesticide entry in aquatic ecosystems. PMID:24431010

  8. In-situ measurements of lunar heat flow

    NASA Technical Reports Server (NTRS)

    Langseth, M. B.; Keihm, S. J.

    1977-01-01

    During the Apollo program two successful heat flow measurements were made in situ on the lunar surface. At the Apollo 15 site a value of .0000031 W/sq cm was measured, and at the Apollo 17 site a value of .0000022 W/sq cm was determined. Both measurements have uncertainty limits of + or - 20 percent and have been corrected for perturbing topographic effects. The apparent difference between the observations may correlate with observed variations in the surface abundance of thorium. Comparison with earlier determinations of heat flow, using the microwave emission spectrum from the moon, gives support to the high gradients and heat flows observed in situ.

  9. Optical sensor for heat conduction measurement in biological tissue

    NASA Astrophysics Data System (ADS)

    Gutierrez-Arroyo, A.; Sanchez-Perez, C.; Aleman-Garcia, N.

    2013-06-01

    This paper presents the design of a heat flux sensor using an optical fiber system to measure heat conduction in biological tissues. This optoelectronic device is based on the photothermal beam deflection of a laser beam travelling in an acrylic slab this deflection is measured with a fiber optic angle sensor. We measure heat conduction in biological samples with high repeatability and sensitivity enough to detect differences in tissues from three chicken organs. This technique could provide important information of vital organ function as well as the detect modifications due to degenerative diseases or physical damage caused by medications or therapies.

  10. In-situ measurements of lunar heat flow

    NASA Technical Reports Server (NTRS)

    Langseth, M. G.; Keihm, S. J.

    1974-01-01

    During the Apollo program two successful heat flow measurements were made in situ on the lunar surface. At the Apollo 15 site a value of 0.0000031 watts/sqcm was measured and at the Apollo 17 site a value of 0.0000022 watts/sqcm was determined. Both measurements have uncertainty limits of + or - 20% and have been corrected for perturbing topographic effects. The apparent difference between the observations may correlate with observed variations in the surface abundance of thorium. Comparison with earlier determinations of heat flow, using the microwave emission spectrum from the moon, gives support to the high gradients and heat flows observed in situ.

  11. A laser-induced heat flux technique for convective heat transfer measurements in high speed flows

    NASA Technical Reports Server (NTRS)

    Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.

    1991-01-01

    A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to the heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the local surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective heat transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective heat transfer coefficients in high-speed flowfields.

  12. A laser-induced heat flux technique for convective heat transfer measurements in high speed flows

    NASA Technical Reports Server (NTRS)

    Porro, A. R.; Keith, T. G., Jr.; Hingst, W. R.

    1991-01-01

    A technique is developed to measure the local convective heat transfer coefficient on a model surface in a supersonic flow field. The technique uses a laser to apply a discrete local heat flux at the model test surface, and an infrared camera system determines the local temperature distribution due to the heating. From this temperature distribution and an analysis of the heating process, a local convective heat transfer coefficient is determined. The technique was used to measure the local surface convective heat transfer coefficient distribution on a flat plate at nominal Mach numbers of 2.5, 3.0, 3.5, and 4.0. The flat plate boundary layer initially was laminar and became transitional in the measurement region. The experimentally determined convective heat transfer coefficients were generally higher than the theoretical predictions for flat plate laminar boundary layers. However, the results indicate that this nonintrusive optical measurement technique has the potential to measure surface convective heat transfer coefficients in high speed flow fields.

  13. Mitigation of NBI-driven Alfvén eigenmodes by electron cyclotron heating in the TJ-II stellarator

    NASA Astrophysics Data System (ADS)

    Nagaoka, K.; Ido, T.; Ascasíbar, E.; Estrada, T.; Yamamoto, S.; Melnikov, A. V.; Cappa, A.; Hidalgo, C.; Pedrosa, M. A.; van Milligen, B. Ph.; Pastor, I.; Liniers, M.; Ochando, M. A.; Shimizu, A.; Eliseev, L. G.; Ohshima, S.; Mukai, K.; Takeiri, Y.; the TJ-II Team

    2013-07-01

    Alfvén eigenmode (AE) activity driven by NBI-produced fast ions is observed in TJ-II plasmas. A two-step response of the measured AEs to electron cyclotron heating (ECH) power is seen. In a first step, the continuous character of the unstable AEs changes to a chirping character of the marginally unstable AEs when moderate values of ECH power are applied to the NBI-only-heated plasma. In a second step, a significant reduction of the AE amplitude is observed when the ECH power is doubled. This stabilizing effect has been experimentally confirmed both on a shot-by-shot basis and along a single discharge by means of ECH modulation. The observed stabilizing effect is stronger with on-axis ECH than with off-axis ECH power injection.

  14. Sensors measure surface ablation rate of reentry vehicle heat shield

    NASA Technical Reports Server (NTRS)

    Russel, J. M., III

    1966-01-01

    Sensors measure surface erosion rate of ablating material in reentry vehicle heat shield. Each sensor, which is placed at precise depths in the heat shield is activated when the ablator surface erodes to the location of a sensing point. Sensor depth and activation time determine ablator surface erosion rate.

  15. Analytical modeling of high precision measurement of thermal heat transfer by laser heating

    NASA Astrophysics Data System (ADS)

    Jain, Abhishek

    2005-04-01

    Study of precise thermal heat transfer due to laser heating of metals and other structures has been found to be of great use in different applications ranging from MEMS, nanostructures and biomedical devices. In this paper an analytical modeling of measuring the temperature at a junction of the thermocouple and the metal surface is done. Analytical treatment is also done to calculate the temperature distribution inside the metal assuming the laser as a point heat source. The metal in consideration is stainless steel and is heated using laser. When a thermocouple is mounted on the metal surface there is a fall in the junction temperature due to the depression of the thermocouple inside the metal, which results in the error in the final measurement. In the present study an analytical investigation is done to measure the error generated due to this depression. Temperature distribution inside the block is also calculated based on heat diffusion equation in cylindrical coordinates.

  16. Dynamic measurement of starch granule swelling during microwave heating.

    PubMed

    Casasnovas, Johnny; Anantheswaran, Ramaswamy C

    2016-10-20

    The size of starch granules in dilute aqueous suspension was measured in-line during gelatinization in a microwave-heated, well-mixed system. The results were compared with those of a previous study conducted with conventional heating. For the starches used (common corn, waxy maize, and cross-linked waxy maize), no significant difference was found between microwave and conventional heating in terms of maximum diameter, temperature of maximum rate of diameter increase, or diameter vs. temperature behavior. These results suggest that there are no differences in the swelling behavior of common and modified maize starches between microwave and conventional heating. PMID:27474654

  17. Making the Handoff from Earthquake Hazard Assessments to Effective Mitigation Measures (Invited)

    NASA Astrophysics Data System (ADS)

    Applegate, D.

    2010-12-01

    This year has witnessed a barrage of large earthquakes worldwide with the resulting damages ranging from inconsequential to truly catastrophic. We cannot predict when earthquakes will strike, but we can build communities that are resilient to strong shaking as well as to secondary hazards such as landslides and liquefaction. The contrasting impacts of the magnitude-7 earthquake that struck Haiti in January and the magnitude-8.8 event that struck Chile in April underscore the difference that mitigation and preparedness can make. In both cases, millions of people were exposed to severe shaking, but deaths in Chile were measured in the hundreds rather than the hundreds of thousands that perished in Haiti. Numerous factors contributed to these disparate outcomes, but the most significant is the presence of strong building codes in Chile and their total absence in Haiti. The financial cost of the Chilean earthquake still represents an unacceptably high percentage of that nation’s gross domestic product, a reminder that life safety is the paramount, but not the only, goal of disaster risk reduction measures. For building codes to be effective, both in terms of lives saved and economic cost, they need to reflect the hazard as accurately as possible. As one of four federal agencies that make up the congressionally mandated National Earthquake Hazards Reduction Program (NEHRP), the U.S. Geological Survey (USGS) develops national seismic hazard maps that form the basis for seismic provisions in model building codes through the Federal Emergency Management Agency and private-sector practitioners. This cooperation is central to NEHRP, which both fosters earthquake research and establishes pathways to translate research results into implementation measures. That translation depends on the ability of hazard-focused scientists to interact and develop mutual trust with risk-focused engineers and planners. Strengthening that interaction is an opportunity for the next generation

  18. Heat of freezing for supercooled water: measurements at atmospheric pressure.

    PubMed

    Cantrell, Will; Kostinski, Alexander; Szedlak, Anthony; Johnson, Alexandria

    2011-06-16

    Unlike reversible phase transitions, the amount of heat released upon freezing of a metastable supercooled liquid depends on the degree of supercooling. Although terrestrial supercooled water is ubiquitous and has implications for cloud dynamics and nucleation, measurements of its heat of freezing are scarce. We have performed calorimetric measurements of the heat released by freezing water at atmospheric pressure as a function of supercooling. Our measurements show that the heat of freezing can be considerably below one predicted from a reversible hydrostatic process. Our measurements also indicate that the state of the resulting ice is not fully specified by the final pressure and temperature; the ice is likely to be strained on a variety of scales, implying a higher vapor pressure. This would reduce the vapor gradient between supercooled water and ice in mixed phase atmospheric clouds. PMID:21087023

  19. Faecal indicator pollution from a dairy farm in Ayrshire, Scotland: source apportionment, risk assessment and potential of mitigation measures.

    PubMed

    Vinten, A J A; Sym, G; Avdic, K; Crawford, Colin; Duncan, A; Merrilees, D W

    2008-02-01

    The objectives of this study were (i) to apportion sources of faecal coliforms (FC) and faecal streptococci (FS) loads from a dairy farm to a stream in the Irvine catchment; (ii) to assess efficacy of pollution mitigation measures installed on this farm; (iii) to assess frequency with which observed FC loads contribute to high risk of failure of coastal bathing water to meet microbial standards. FC and FS loads in a primary stream running through the farm were estimated at up to four stations (above the farm, above the steading, below the farm and below a pre-existing 0.6 ha area of open water/wetland), in summer 2004 and 2005. During this period, steading and field mitigation measures were being installed. We estimated that farm FC loads likely to cause bathing water failure were 8.9 x 10(8) colony-forming units (cfu) ha(-1)d(-1) (guideline standards) and 1.7 x 10(10)cfu ha(-1)d(-1) (mandatory standards). In 2005, the guideline exceedance risk (42%) was associated about equally with field and steading sources, whereas the mandatory exceedance risk (11%) was mainly due to steading sources. The pond/wetland below the farm reduced these exceedance risks to 20% and <1%, respectively, but was a source of FS at high discharge. The exceedence curves below the farm were similar in 2004 and 2005, despite lower flows and installation of pollution mitigation measures. The results suggest that further mitigation efforts on this farm should be focused on improving management of the steading FC sources and that wetlands to receive steading runoff can be cost:effective mitigation tools for faecal indicator pollution. PMID:18001813

  20. Effect of radiation heat transfer on thermal diffusivity measurements

    NASA Astrophysics Data System (ADS)

    Araki, N.

    1990-03-01

    Experimental data on thermal conductivity and thermal diffusivity of a semitransparent material generally include an error due to the radiation heat transfer. This error varies in accordance with the experimental conditions such as the temperature level of the sample and the measuring method. In this paper, research on the influence of radiation heat transfer on thermal diffusivity are reviewed, and as an example, the method to correct the radiation component in the apparent thermal diffusivity measured by the stepwise heating technique is presented. The transient heat transfer by simultaneous thermal conduction and radiation in a semitransparent material is analyzed when the front surface is subjected to stepwise heating. The apparent thermal diffusivity, which includes the radiation component, is calculated for various parameters.

  1. TLD measurements of gamma heating in heavy elements.

    NASA Technical Reports Server (NTRS)

    Reilly, H. J.; Robinson, R. A.; Peters, L. E., Jr.

    1971-01-01

    Measurements and calculations of gamma heating in polyethylene and lead containers were done and compared. The objective was to provide a workable method of getting good values for gamma heating in in-pile experiments containing materials of high atomic numbers. It was inferred that a combination of thermoluminescent dosimeter measurements, using Bragg-Gray theory, with photon transport calculations using the ANISN computer program, would meet this objective.

  2. Method of measuring heat influx of a cryogenic transfer system

    DOEpatents

    Niemann, Ralph C.; Zelipsky, Steven A.; Rezmer, Ronald R.; Smelser, Peter

    1981-01-01

    A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

  3. Severe accident approach - final report. Evaluation of design measures for severe accident prevention and consequence mitigation.

    SciTech Connect

    Tentner, A. M.; Parma, E.; Wei, T.; Wigeland, R.; Nuclear Engineering Division; SNL; INL

    2010-03-01

    An important goal of the US DOE reactor development program is to conceptualize advanced safety design features for a demonstration Sodium Fast Reactor (SFR). The treatment of severe accidents is one of the key safety issues in the design approach for advanced SFR systems. It is necessary to develop an in-depth understanding of the risk of severe accidents for the SFR so that appropriate risk management measures can be implemented early in the design process. This report presents the results of a review of the SFR features and phenomena that directly influence the sequence of events during a postulated severe accident. The report identifies the safety features used or proposed for various SFR designs in the US and worldwide for the prevention and/or mitigation of Core Disruptive Accidents (CDA). The report provides an overview of the current SFR safety approaches and the role of severe accidents. Mutual understanding of these design features and safety approaches is necessary for future collaborations between the US and its international partners as part of the GEN IV program. The report also reviews the basis for an integrated safety approach to severe accidents for the SFR that reflects the safety design knowledge gained in the US during the Advanced Liquid Metal Reactor (ALMR) and Integral Fast Reactor (IFR) programs. This approach relies on inherent reactor and plant safety performance characteristics to provide additional safety margins. The goal of this approach is to prevent development of severe accident conditions, even in the event of initiators with safety system failures previously recognized to lead directly to reactor damage.

  4. The nitrogen fate beyond the current nutrient mitigation measures: sustainability of an integrated agriculture

    NASA Astrophysics Data System (ADS)

    Thieu, V.; Billen, G. F.; Garnier, J.; Lancelot, C.; Gypens, N.

    2010-12-01

    Located in the North-Western Europe the terrestrial continuum that includes the Seine, Somme, and Scheldt River basins offers an interesting example of a transborder territory (France, Belgium, and Netherlands) with high-intensity anthropogenic pressures. It well-illustrates the rapid development of modern agriculture in industrialised countries and the resulting severe alteration of water resources and jeopardising the capacity of rural territories to produce drinking water. The corresponding nutrient loads delivered then into the Southern Bight of the North Sea, strongly affect the ecological functioning of the coastal zone. An integrated ‘river-ocean’ assessment, coupling two deterministic models - the SENEQUE RIVESTRAHLER model simulating nutrient dynamic in the drainage network and the MIRO model describing the ecological functioning coastal ecosystem - points out the relevance of current policy based measures (improvement of waste water treatment) to mitigate phosphorous emissions, while the nitrogen pollution related to agriculture will remain critical despite the implementation of classical management measure (good agricultural practices). Therefore and irrespectively of the current political agenda, a more radical alternative is established, consisting of a generalised shift to an integrated agriculture of all agricultural areas in the three basins, excluding the use of synthetically compounded fertilisers and the importation of livestock feed. Such scenario aims at evaluating whether agriculture, by essence, can conciliate (i) the demand for food and feed by local populations, (ii) a good ecological functioning of aquatic ecosystems and (iii) a balanced nutrient status for the adjacent coastal area. This scenario involves an increased livestock density in the Seine and Somme and a decrease in livestock in the Scheldt basin. It leads to a significant reduction of agricultural production that finally brings the three basins closer to autotrophy

  5. Divertor Heat Flux Mitigation in High-Performance H-mode Discharges in the National Spherical Torus Experiment.

    SciTech Connect

    Soukhanovskii, V A; Maingi, R; Gates, D; Menard, J

    2008-12-31

    Experiments conducted in high-performance 1.0 MA and 1.2 MA 6 MW NBI-heated H-mode discharges with a high magnetic flux expansion radiative divertor in NSTX demonstrate that significant divertor peak heat flux reduction and access to detachment may be facilitated naturally in a highly-shaped spherical torus (ST) configuration. Improved plasma performance with high {beta}{sub t} = 15-25%, a high bootstrap current fraction f{sub BS} = 45-50%, longer plasma pulses, and an H-mode regime with smaller ELMs has been achieved in the strongly-shaped lower single null configuration with elongation {kappa} = 2.2-2.4 and triangularity {delta} = 0.6-0.8. Divertor peak heat fluxes were reduced from 6-12 MW/m{sup 2} to 0.5-2 MW/m{sup 2} in ELMy H-mode discharges using the inherently high magnetic flux expansion f{sub m} = 16-25 and the partial detachment of the outer strike point at several D{sub 2} injection rates. A good core confinement and pedestal characteristics were maintained, while the core carbon concentration and the associated Z{sub eff} were reduced. The partially detached divertor regime was characterized by an increase in divertor radiated power, a reduction of ion flux to the plate, and a large neutral compression ratio. Spectroscopic measurements indicated a formation of a high-density, low temperature region adjacent to the outer strike point, where substantial increases in the volume recombination rate and CII, CIII emission rates was measured.

  6. Measurement of heat transfer coefficients by nuclear magnetic resonance.

    PubMed

    Gultekin, David H; Gore, John C

    2008-11-01

    We demonstrate an experimental method for the measurement of heat transfer coefficient for a fluid system by magnetic resonance imaging. In this method, the temporal variation of thermally induced nuclear shielding is monitored and the average heat transfer coefficient is measured as a function of fluid velocity. We examine the cases of natural convection and forced convection at fluid velocity up to 0.8 m s(-1). These cases correspond to low dimensionless Biot (Bi) number where the heat transfer is limited by thermal convection. We demonstrate the NMR method for two simple geometries, a cylinder and a sphere, to experimentally determine the heat transfer coefficient (h) in two NMR imaging and spectroscopy systems through measuring three NMR parameters, the chemical shift, magnetization and spin self diffusion coefficient. PMID:18524523

  7. The measurement of capsule heat transfer gaps using neutron radiography.

    NASA Technical Reports Server (NTRS)

    Thaler, L. A.

    1971-01-01

    The use of neutron radiographs to determine dimensional changes of heat transfer gaps in cylindrical nuclear fueled capsules is described. A method was developed which involves scanning a very fine grained neutron radiograph negative with a recording microdensitometer. The output of the densitometer is recorded on graph paper and the heat transfer gap is plotted as a well-defined optical density change. Calibration of the recording microdensitometer ratio arms permits measurements to be made of the heat transfer optical density change from the microdensitometer trace. Total heat transfer gaps, measured by this method, agree with the physical measurements within plus or minus 0.005 cm over a range of gaps from 0.061 to 0.178 cm.

  8. Measurement of capsule heat transfer gaps using neutron radiography

    NASA Technical Reports Server (NTRS)

    Thaler, L. A.

    1974-01-01

    A technique is described for measuring heat transfer gaps from neutron radiographs. The method involves scanning the radiograph negative with a recording microdensitometer to obtain a trace of the optical density variation across the diameter of the capsule. The optical density change representing the gap is measured from the microdensitometer trace and related to the physical measurement. Heat transfer gaps from 0.061 to 0.178 cm have been determined by this technique and agree with preassembly physical measurements to plus or minus 0.005 cm.

  9. Heat flux measurements for use in physiological and clothing research.

    PubMed

    Niedermann, R; Psikuta, A; Rossi, R M

    2014-08-01

    Scientists use passive heat flow meters to measure body heat exchanges with the environment. In recent years, several such sensors have been developed and concerns about their proper calibration have been addressed. However, calibration methods have differed in the geometry of the heated device as well as in the heat transfer mechanism. Therefore, a comparison of calibration methods is needed in order to understand the obtained differences in calibration lines. We chose three commercially available heat flux sensors and placed them on four different heated devices: a hot plate, double hot plate, nude cylinder and a cylinder covered with a spacer material. We found differences between the calibration line of the manufacturer and our own measurements, especially when forced convection was involved as the main heat transfer mechanism. The results showed clearly that the calibration method should be chosen according to the intended purpose of use. In addition, we recommend use a thin, light heat flux sensor with good thermal conduction in human subject studies. PMID:23824222

  10. Measured Performance of a Low Temperature Air Source Heat Pump

    SciTech Connect

    Johnson, R. K.

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor 'boosted heat pump' technology. The Low Temperature Heat Pumpsystem operates with four increasing levels of capacity (heat output) as the outdoor temperature drops. The system was shown to select capacity correctly, supplying the appropriate amount of heat to the house across the full range of outdoor temperatures. The system's Coefficient of Performance (Seasonal COP, or SCOP) over two entire winters was calculated, based on measured data, to be 3.29over the first winter and 2.68 over the second winter. A second seasonal efficiency calculation by a different method yielded a SCOP of 2.78 for the first winter and 2.83 for the second winter. This second seasonal efficiency calculation was determined by comparing measured heat pump energy use to the in situ energy use with resistance heat alone. This method is the ratio of the slopes of thedaily energy use load lines.

  11. Heat flux measurements for use in physiological and clothing research

    NASA Astrophysics Data System (ADS)

    Niedermann, R.; Psikuta, A.; Rossi, R. M.

    2014-08-01

    Scientists use passive heat flow meters to measure body heat exchanges with the environment. In recent years, several such sensors have been developed and concerns about their proper calibration have been addressed. However, calibration methods have differed in the geometry of the heated device as well as in the heat transfer mechanism. Therefore, a comparison of calibration methods is needed in order to understand the obtained differences in calibration lines. We chose three commercially available heat flux sensors and placed them on four different heated devices: a hot plate, double hot plate, nude cylinder and a cylinder covered with a spacer material. We found differences between the calibration line of the manufacturer and our own measurements, especially when forced convection was involved as the main heat transfer mechanism. The results showed clearly that the calibration method should be chosen according to the intended purpose of use. In addition, we recommend use a thin, light heat flux sensor with good thermal conduction in human subject studies.

  12. Communicating risk and promoting disease mitigation measures in epidemics and emerging disease settings

    PubMed Central

    Schiavo, Renata; Leung, May May; Brown, Mason

    2014-01-01

    Objective This review aims to identify and assess evidence on interventions to communicate risk and promote disease mitigation measures in epidemics and emerging disease outbreak settings. The study focuses on data that are relevant to low and middle-income country (LMIC) settings. Methods We conducted a comprehensive literature search using five major electronic databases (Pubmed Medline, Biomed Central, EMBASE, Science of Citation Index, and Cochrane Library) and other sources to identify relevant studies published from January 2002 to July 2013. The review was guided by the socio-ecological model/perspective of public health and the ideation theory and focused on interventions at the community, healthcare, and multi-sectoral settings, which also reflect key intervention levels of the Ottawa Charter for Health Promotion. Eligible quantitative studies were selected according to specific study criteria and assessed using the Critical Appraisal Skills Program (CASP) framework. Conversely, qualitative studies, reviews, case studies, and editorials were not included. Studies were selected by two independent reviewers. Results Twenty-nine relevant studies from 16 countries were included. Most studies focused on a single intervention or intervention level, rather than multi-sectoral interventions. The majority of the evidence relates to programs aimed at behavioral and social results (or relevant intermediate steps) within a specific population group. Two studies included implications for improvements in health service delivery, two studies examined the intervention’s impact on health systems-related outcomes, and three had also implications for environmental health outcomes. Cost- and health equity-related implications for select evidence were also discussed. Conclusions The paucity of well-designed quantitative evaluations of interventions to communicate health risk and promote disease control measures in LMICs does not allow for any definitive conclusions. Yet, the

  13. Heat transfer measurements and CFD simulations of an impinging jet

    NASA Astrophysics Data System (ADS)

    Petera, Karel; Dostál, Martin

    2016-03-01

    Heat transport in impinging jets makes a part of many experimental and numerical studies because some similarities can be identified between a pure impingement jet and industrial processes like, for example, the heat transfer at the bottom of an agitated vessel. In this paper, experimental results based on measuring the response to heat flux oscillations applied to the heat transfer surface are compared with CFD simulations. The computational cost of a LES-based approach is usually too high therefore a comparison with less computationally expensive RANS-based turbulence models is made in this paper and a possible improvement of implementing an anisotropic explicit algebraic model for the turbulent heat flux model is evaluated.

  14. Partial radiogenic heat model for Earth revealed by geoneutrino measurements

    NASA Astrophysics Data System (ADS)

    Kamland Collaboration; Gando, A.; Gando, Y.; Ichimura, K.; Ikeda, H.; Inoue, K.; Kibe, Y.; Kishimoto, Y.; Koga, M.; Minekawa, Y.; Mitsui, T.; Morikawa, T.; Nagai, N.; Nakajima, K.; Nakamura, K.; Narita, K.; Shimizu, I.; Shimizu, Y.; Shirai, J.; Suekane, F.; Suzuki, A.; Takahashi, H.; Takahashi, N.; Takemoto, Y.; Tamae, K.; Watanabe, H.; Xu, B. D.; Yabumoto, H.; Yoshida, H.; Yoshida, S.; Enomoto, S.; Kozlov, A.; Murayama, H.; Grant, C.; Keefer, G.; Piepke, A.; Banks, T. I.; Bloxham, T.; Detwiler, J. A.; Freedman, S. J.; Fujikawa, B. K.; Han, K.; Kadel, R.; O'Donnell, T.; Steiner, H. M.; Dwyer, D. A.; McKeown, R. D.; Zhang, C.; Berger, B. E.; Lane, C. E.; Maricic, J.; Miletic, T.; Batygov, M.; Learned, J. G.; Matsuno, S.; Sakai, M.; Horton-Smith, G. A.; Downum, K. E.; Gratta, G.; Tolich, K.; Efremenko, Y.; Perevozchikov, O.; Karwowski, H. J.; Markoff, D. M.; Tornow, W.; Heeger, K. M.; Decowski, M. P.

    2011-09-01

    The Earth has cooled since its formation, yet the decay of radiogenic isotopes, and in particular uranium, thorium and potassium, in the planet's interior provides a continuing heat source. The current total heat flux from the Earth to space is 44.2+/-1.0TW, but the relative contributions from residual primordial heat and radiogenic decay remain uncertain. However, radiogenic decay can be estimated from the flux of geoneutrinos, electrically neutral particles that are emitted during radioactive decay and can pass through the Earth virtually unaffected. Here we combine precise measurements of the geoneutrino flux from the Kamioka Liquid-Scintillator Antineutrino Detector, Japan, with existing measurements from the Borexino detector, Italy. We find that decay of uranium-238 and thorium-232 together contribute TW to Earth's heat flux. The neutrinos emitted from the decay of potassium-40 are below the limits of detection in our experiments, but are known to contribute 4TW. Taken together, our observations indicate that heat from radioactive decay contributes about half of Earth's total heat flux. We therefore conclude that Earth's primordial heat supply has not yet been exhausted.

  15. Time and Space Resolved Heat Flux Measurements During Nucleate Boiling with Constant Heat Flux Boundary Conditions

    NASA Technical Reports Server (NTRS)

    Yerramilli, Vamsee K.; Myers, Jerry G.; Hussey, Sam W.; Yee, Glenda F.; Kim, Jungho

    2005-01-01

    The lack of temporally and spatially resolved measurements under nucleate bubbles has complicated efforts to fully explain pool-boiling phenomena. The objective of this current work was to acquire time and space resolved temperature distributions under nucleating bubbles on a constant heat flux surface using a microheater array with 100x 100 square microns resolution, then numerically determine the wall to liquid heat flux. This data was then correlated with high speed (greater than l000Hz) visual recordings of The bubble growth and departure from the heater surface acquired from below and from the side of the heater. The data indicate that microlayer evaporation and contact line heat transfer are not major heat transfer mechanisms for bubble growth. The dominant heat transfer mechanism appears to be transient conduction into the liquid as the liquid rewets the wall during the bubble departure process.

  16. Are changes in weather masking the efficacy of measures aimed at mitigating diffuse pollution?

    NASA Astrophysics Data System (ADS)

    Mellander, Per-Erik; Jordan, Phil; Shore, Mairead; McDonald, Noeleen; Shortle, Ger

    2016-04-01

    Interpretations of the efficacy of mitigation measures for reducing nitrogen (N) and phosphorus (P) losses from agricultural sources to water bodies are challenged by the temporal variability of air temperature and rainfall. Influences are different depending on flow controls, associated time lags and nutrient transformations that may occur along the pathways. In Europe weather patterns and trends are influenced by large-scale weather systems over the North Atlantic. One of the most prominent teleconnection patterns that affect the weather across all seasons is the North Atlantic Oscillation (NAO). In northwestern Europe a positive phase in the NAO index over the winter period is often associated with elevated air temperatures in summer and more frequent large rain events in winter than normal. The objective of this study was to investigate the catchment-scale influences and relationships of naturally altered hydro-meteorological processes on the diffuse N and P losses to waters, in order to distinguish natural climate effects from those caused by adaptive management (increased agricultural intensity, decreased nutrient use etc.). Here we present six years of monthly nitrate-N and total reactive P concentrations in stream water (aggregated from sub-hourly monitoring) in six, ca. 10 km2, Irish agricultural catchments with different hydrological flow controls and land use. The locations of the catchments make them susceptible to sudden and/or seasonal shifts in weather. Changes in long term air temperatures and rainfall were investigated and annual N and P concentrations were compared to the NAO. During the monitored period (2009-2015) there was a steady increase in wintertime NAO index, reaching positive values in recent years, resulting in higher air temperatures and more frequent large rain events in winter. In some settings annual N and/or P concentrations were positively correlated to the three-year moving average NAO index (R2 > 0.90). Catchments with free

  17. Simultaneous measurement of heat capacity and internal relaxation time.

    PubMed

    Nagasawa, Mitsuharu

    2016-05-01

    A new steady-state method is proposed to simultaneously measure the heat capacity and internal relaxation time using superimposed constant and square-wave power. This method is appropriate for small sample systems with low thermal conductance. The accuracies of the heat capacity and internal relaxation time are almost the same as those determined using other similar methods, but correction for the effect of internal relaxation on the heat capacity is more flexible. The thermal diffusivity and thermal conductivity are also simultaneously determined for rod- and slab-shaped samples. We demonstrate the method for small slabs of synthetic silica in the 80-320 K temperature range. PMID:27250459

  18. Accurate Measurement of Heat Capacity by Differential Scanning Calorimetry

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Experience with high quality heat capacity measurement by differential scanning calorimetry is summarized and illustrated, pointing out three major causes of error: (1) incompatible thermal histories of the sample, reference and blank runs; (2) unstable initial and final isotherms; (3) incompatible differences between initial and final isotherm amplitudes for sample, reference and blank runs. Considering these problems, it is shown for the case of polyoxymethylene that accuracies in heat capacity of 0.1 percent may be possible.

  19. High heat flux measurements and experimental calibrations/characterizations

    NASA Technical Reports Server (NTRS)

    Kidd, Carl T.

    1992-01-01

    Recent progress in techniques employed in the measurement of very high heat-transfer rates in reentry-type facilities at the Arnold Engineering Development Center (AEDC) is described. These advances include thermal analyses applied to transducer concepts used to make these measurements; improved heat-flux sensor fabrication methods, equipment, and procedures for determining the experimental time response of individual sensors; performance of absolute heat-flux calibrations at levels above 2,000 Btu/cu ft-sec (2.27 kW/cu cm); and innovative methods of performing in-situ run-to-run characterizations of heat-flux probes installed in the test facility. Graphical illustrations of the results of extensive thermal analyses of the null-point calorimeter and coaxial surface thermocouple concepts with application to measurements in aerothermal test environments are presented. Results of time response experiments and absolute calibrations of null-point calorimeters and coaxial thermocouples performed in the laboratory at intermediate to high heat-flux levels are shown. Typical AEDC high-enthalpy arc heater heat-flux data recently obtained with a Calspan-fabricated null-point probe model are included.

  20. Unsteady heat transfer measurements on a rotating gas turbine blade

    NASA Astrophysics Data System (ADS)

    Hilditch, M. A.; Ainsworth, R. W.

    1990-06-01

    This paper presents heat transfer measurements made on the rotor blade of a full-stage model turbine operating at engine representative conditions. The measurement technique of mounting thin film heat transfer gauges on enamel-coated turbine blades enables the heat transfer rate to be measured across a frequency range of dc to 100 KHz. A calibration experiment in which the gauge is pulsed with a laser beam is described in detail. The results are compared with data from a previous 2D simulation of wake-passing flow in the midheight section of the same blade. The mean heat transfer rate recorded in the two experiments shows reasonable agreement. Fluctuations in the unsteady heat transfer signal at nozzle-guide-vane passing frequency are seen at the same locations in data from both experiments. The magnitude of the fluctuations seen on the rotor are much smaller than those recorded in the 2D simulation. Frequency spectra and correlation analysis of heat transfer traces recorded on the rotor are also presented.

  1. Examples of cooler reflective streets for urban heat-island mitigation : Portland cement concrete and chip seals

    SciTech Connect

    Pomerantz, M.; Akbari, H.; Chang, S.-C.; Levinson, R.; Pon, B.

    2003-04-30

    Part of the urban heat island effect can be attributed to dark pavements that are commonly used on streets and parking lots. In this paper we consider two light colored, hence cooler, alternative paving materials that are in actual use in cities today. These are Portland cement concrete (PCC) pavements and chip seals. We report measurements of the albedos of some PCC and chip sealed pavements in the San Francisco Bay Area. The albedos of the PCC pavements ranged from about 0.18 to 0.35. The temperatures of some PCC pavements are also measured and calculated. We then consider how the albedos of the constituent materials of the PCC (stone, sand and cement) contribute to the albedos of the resulting finished concrete. The albedos of a set of chip sealed pavements in San Jose, CA, were measured and correlated with the times of their placement. It is found that the albedos decrease with age (and use) but remain higher than that of standard asphalt concrete (AC) for about five years. After t hat, the albedos of the chip seals are about 0.12, similar to aged AC. The fact that many PCC pavements have albedos at least twice as high as aged AC suggests that it is possible to have pavement albedos that remain high for many years.

  2. A review of monitoring approaches and outcomes of surface water quality mitigation measures in meso-scale agricultural catchments

    NASA Astrophysics Data System (ADS)

    Melland, Alice; Jordan, Phil; Murphy, Paul; Mellander, Per-Erik; Shortle, Ger

    2013-04-01

    Critical for an informative feedback loop from scientific monitoring of biophysical change, to making and implementing suitable policy to effect the desired change, are both accurate measurement of biophysical change, and measurement or modelling of the causes of change. For example the European Environment Agency uses the DPSIR framework to assess change in the state (S) of natural resources due to changes in specific drivers (D) and pressures (P) that can have an impact (I) and are the focus of policy responses (R). This paper provides a review of meso-catchment scale studies worldwide that have measured the impacts of agricultural land management practice on surface water quality. Approaches for measuring water quality impacts of agricultural mitigation practices in meso-catchments (1-100 km2) ranged from measuring water quality over a time series, such as before and after a land management change, or over a spatial series such as in paired catchments with and without agricultural practice change (or over a gradient of practices or catchment types), and by cause and effect studies that measure sources, pathways and impacts of practices. Agricultural mitigation measures had no measurable effect, or positive, or negative effects on water quality over periods of 3 to 20 years. In most catchments where beneficial effects of mitigation measures were successfully measured, combinations of measures that address nutrient or pollutant sources, pathways, delivery and impact have been implemented. Successful farm measures included substantial reductions in the intensity of the farming systems, improved engineering and crop management to reduce runoff and drainage transport of nutrients and sediment, as well as high rates of implementation of measures across the catchments. In many cases, the potential to measure improvement in one or more water quality indicators was limited by the impact of a few management or weather events. Reasons that water quality did not improve in

  3. Spatially resolved heat release rate measurements in turbulent premixed flames

    SciTech Connect

    Ayoola, B.O.; Kaminski, C.F.; Balachandran, R.; Mastorakos, E.; Frank, J.H.

    2006-01-01

    Heat release rate is a fundamental property of great importance for the theoretical and experimental elucidation of unsteady flame behaviors such as combustion noise, combustion instabilities, and pulsed combustion. Investigations of such thermoacoustic interactions require a reliable indicator of heat release rate capable of resolving spatial structures in turbulent flames. Traditionally, heat release rate has been estimated via OH or CH radical chemiluminescence; however, chemiluminescence suffers from being a line-of-sight technique with limited capability for resolving small-scale structures. In this paper, we report spatially resolved two-dimensional measurements of a quantity closely related to heat release rate. The diagnostic technique uses simultaneous OH and CH{sub 2}O planar laser-induced fluorescence (PLIF), and the pixel-by-pixel product of the OH and CH{sub 2}O PLIF signals has previously been shown to correlate well with local heat release rates. Results from this diagnostic technique, which we refer to as heat release rate imaging (HR imaging), are compared with traditional OH chemiluminescence measurements in several flames. Studies were performed in lean premixed ethylene flames stabilized between opposed jets and with a bluff body. Correlations between bulk strain rates and local heat release rates were obtained and the effects of curvature on heat release rate were investigated. The results show that the heat release rate tends to increase with increasing negative curvature for the flames investigated for which Lewis numbers are greater than unity. This correlation becomes more pronounced as the flame gets closer to global extinction.

  4. Construction and measurements of an improved vacuum-swing-adsorption radon-mitigation system

    SciTech Connect

    Street, J. Bunker, R.; Dunagan, C.; Loose, X.; Schnee, R. W.; Stark, M.; Sundarnath, K.; Tronstad, D.

    2015-08-17

    In order to reduce backgrounds from radon-daughter plate-out onto detector surfaces, an ultra-low-radon cleanroom is being commissioned at the South Dakota School of Mines and Technology. An improved vacuum-swing-adsorption radon mitigation system and cleanroom build upon a previous design implemented at Syracuse University that achieved radon levels of ∼0.2 Bq m{sup −3}. This improved system will employ a better pump and larger carbon beds feeding a redesigned cleanroom with an internal HVAC unit and aged water for humidification. With the rebuilt (original) radon mitigation system, the new low-radon cleanroom has already achieved a > 300× reduction from an input activity of 58.6 ± 0.7 Bq m{sup −3} to a cleanroom activity of 0.13 ± 0.06 Bq m{sup −3}.

  5. Construction and measurements of an improved vacuum-swing-adsorption radon-mitigation system

    NASA Astrophysics Data System (ADS)

    Street, J.; Bunker, R.; Dunagan, C.; Loose, X.; Schnee, R. W.; Stark, M.; Sundarnath, K.; Tronstad, D.

    2015-08-01

    In order to reduce backgrounds from radon-daughter plate-out onto detector surfaces, an ultra-low-radon cleanroom is being commissioned at the South Dakota School of Mines and Technology. An improved vacuum-swing-adsorption radon mitigation system and cleanroom build upon a previous design implemented at Syracuse University that achieved radon levels of ˜0.2 Bq m-3. This improved system will employ a better pump and larger carbon beds feeding a redesigned cleanroom with an internal HVAC unit and aged water for humidification. With the rebuilt (original) radon mitigation system, the new low-radon cleanroom has already achieved a > 300× reduction from an input activity of 58.6 ± 0.7 Bq m-3 to a cleanroom activity of 0.13 ± 0.06 Bq m-3.

  6. Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

    NASA Astrophysics Data System (ADS)

    Campbell, J. M.; Jordan, P.; Arnscheidt, J.

    2015-01-01

    This study reports the use of high-resolution water quality monitoring to assess the influence of changes in land use management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the issue of agricultural soil P management and subsequent diffuse transfers at high river flows over a 5-year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STSs) and mitigation efforts - a key concern for catchment management. Results showed an inconsistent response to soil P management over 5 years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STSs) and also to gauge their effectiveness.

  7. Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

    NASA Astrophysics Data System (ADS)

    Campbell, J. M.; Jordan, P.; Arnscheidt, J.

    2014-09-01

    This study reports the use of high resolution water quality monitoring to assess the influence of changes in landuse management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the "wicked problem" of agricultural soil P management and subsequent diffuse transfers at high river flows over a five year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STS) and mitigation efforts - here termed the "filthy issue" of rural catchment management. Results showed an inconsistent response to soil P management over five years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STS) and also to gauge their effectiveness.

  8. Evaporation Measured In Situ by Sensible Heat Balance

    NASA Astrophysics Data System (ADS)

    Heitman, Josh; Xiao, Xinhua; Sauer, Thomas; Ren, Tusheng; Horton, Robert

    2016-04-01

    Measurement of evaporation independent from evapotranspiration remains a major challenge for quantifying water fluxes in the soil-plant-atmosphere system. Methodology based on soil sensible heat balance (SHB) has been developed to measure in situ, sub-surface soil water evaporation with heat-pulse sensors. Soil sensible heat flux and change in heat storage are measured at multiple depths near the soil surface, and a simple energy balance calculation is applied to determine latent heat flux (i.e., evaporation) as a residual. For bare surface conditions, comparison of SHB to micrometerological (Bowen ratio) and micro-lysimeter approaches indicates strong correlation (r2 = 0.96) with near 1:1 relationship and root mean square error of 0.2 mm/d. Recent efforts to apply SHB methodology in row-crop (maize) and vineyard systems demonstrate the potential for quantifying evaporation separate from evapotranspiration. For the maize system, SHB evaporation estimates differed from micro-lysimeters by < 0.2 mm/d. The SHB approach is one of very few measurement approaches that may be applied to partition evaporation from evapotranspiration.

  9. Corrections of Heat Flux Measurements on Launch Vehicles

    NASA Technical Reports Server (NTRS)

    Reinarts, Thomas R.; Matson, Monique L.; Walls, Laurie K.

    2002-01-01

    Knowledge of aerothermally induced convective heat transfer is important in the design of thermal protection systems for launch vehicles. Aerothermal models are typically calibrated via the data from circular, in-flight, flush-mounted surface heat flux gauges exposed to the thermal and velocity boundary layers of the external flow. Typically, copper or aluminum Schmidt- Boelter gauges, which take advantage of the one-dimensional Fourier's law of heat conduction, are used to measure the incident heat flux. This instrumentation, when surrounded by low-conductivity insulation, has a wall temperature significantly lower than the insulation. As a result of this substantial disturbance to the thermal boundary layer, the heat flux incident on the gauge tends to be considerably higher than it would have been on the insulation had the calorimeter not been there. In addition, radial conductive heat transfer from the hotter insulation can cause the calorimeter to indicate heat fluxes higher than actual. An overview of an effort to develop and calibrate gauge correction techniques for both of these effects will be presented.

  10. Basic data for some recent Australian heat-flow measurements

    USGS Publications Warehouse

    Munroe, Robert J.; Sass, J.H.; Milburn, G.T.; Jaeger, J.C.; Tammemagi, H.Y.

    1975-01-01

    This report has been compiled to provide background information and detailed temperature and thermal conductivity data for the heat-flow values reported in Sass, Jaeger, and Munroe (in press). The data were collected as part of a joint heat-flow study by the Australian National University (ANU) and the U.S. Geological Survey (USGS) under the direction of J. C. Jaeger (ANU) and J. H. Sass (USGS). The format is similar to that used for basic data from United States heat-flow determinations (Sass and Munroe, 1974). Each section contains a state map showing the geographic distribution of heat-flow data followed by tables which list individual temperatures, thermal conductivities, and radiogenic heat production values. A companion volume (Bunker and others, 1975) gives details of the heat-production measurements together with individual radioelement concentrations. Localities are arranged in alphabetical order within each state. The methods and techniques of measurements have been described by Sass and others (1971a, b). Unusual methods or procedures which differ markedly from these techniques are noted and described in the comments sections of the tables.

  11. Heating rate controller for thermally stimulated conductivity and thermoluminescence measurements.

    NASA Technical Reports Server (NTRS)

    Manning, E. G.; Littlejohn, M. A.; Oakley, E. M.; Hutchby , J. A.

    1972-01-01

    A temperature controller is described which enables the temperature of a sample mounted on a cold finger to be varied linearly with time. Heating rates between 0.5 and 10 K/min can be achieved for temperatures between 90 and 300 K. Provision for terminating the sample heating at any temperature between these extremes is available. The temperature can be held at the terminating temperature or be reduced to the starting temperature in a matter of minutes. The controller has been used for thermally stimulated conductivity measurements and should be useful for thermoluminescence measurements as well.

  12. The contribution of urbanization to recent extreme heat events and white roof mitigation strategy in the Beijing-Tianjin-Hebei metropolitan area

    NASA Astrophysics Data System (ADS)

    Wang, Mingna

    2015-04-01

    The UHI effect can aggravate summertime heat waves and strongly influence human comfort and health, leading to greater mortality in metropolitan areas. Many geo-engineering technological strategies have been proposed to mitigate climate warming, and for the UHI, increasing the albedo of artificial urban surfaces (rooftops or pavements) has been considered a lucrative and effective way to cool cities. The objective of this work is to quantify the contribution of urbanization to recent extreme heat events of the early 21st century in the Beijing-Tianjin-Hebei metropolitan area, using the mesoscale WRF model coupled with a single urban canopy model and actual urban land cover datasets. This work also investigates a simulation of the regional effects of white roof technology by increasing the albedo of urban areas in the urban canopy model to mitigate the urban heat island, especially in extreme heat waves. The results show that urban land use characteristics that have evolved over the past ~20 years in the Beijing-Tianjin-Hebei metropolitan area have had a significant impact on the extreme temperatures occurring during extreme heat events. Simulations show that new urban development has caused an intensification and expansion of the areas experiencing extreme heat waves with an average increase in temperature of approximately 0.60°C. This change is most obvious at night with an increase up to 0.95°C, for which the total contribution of anthropogenic heat is 34%. We also simulate the effects of geo-engineering strategies increasing the albedo of urban roofs. White roofs reflect a large fraction of incoming sunlight in the daytime, which reduced the net radiation so that the roof surface keep at a lower temperature than regular solar-absorptive roofs. Urban net radiation decreases by approximately 200 W m-2 at local noon because of high solar reflectance of white roofs, which cools the daytime urban temperature afer sunrise, with the largest decrease of almost -0.80

  13. Direct electronic measurement of Peltier cooling and heating in graphene

    PubMed Central

    Vera-Marun, I. J.; van den Berg, J. J.; Dejene, F. K.; van Wees, B. J.

    2016-01-01

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 μA at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials. PMID:27161186

  14. Heat flow measurements on the southeast coast of Australia

    USGS Publications Warehouse

    Hyndman, R.D.; Jaeger, J.C.; Sass, J.H.

    1969-01-01

    Three boreholes have been drilled for the Australian National University near the southeast coast of New South Wales, Australia. The heat flows found are 1.1, 1.0, and 1.3 ??cal/cm2sec. The errors resulting from the proximity of the sea and a lake, surface temperature change, conductivity structure and water flow have been examined. The radioactive heat production in some of the intrusive rocks of the area have also been measured. The heat flows are much lower than the values of about 2.0 found elsewhere in south eastern Australia. The lower values appear to be part of a distinct heat flow province in eastern Australia. ?? 1969.

  15. Direct electronic measurement of Peltier cooling and heating in graphene

    NASA Astrophysics Data System (ADS)

    Vera-Marun, I. J.; van den Berg, J. J.; Dejene, F. K.; van Wees, B. J.

    2016-05-01

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 μA at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials.

  16. Direct electronic measurement of Peltier cooling and heating in graphene.

    PubMed

    Vera-Marun, I J; van den Berg, J J; Dejene, F K; van Wees, B J

    2016-01-01

    Thermoelectric effects allow the generation of electrical power from waste heat and the electrical control of cooling and heating. Remarkably, these effects are also highly sensitive to the asymmetry in the density of states around the Fermi energy and can therefore be exploited as probes of distortions in the electronic structure at the nanoscale. Here we consider two-dimensional graphene as an excellent nanoscale carbon material for exploring the interaction between electronic and thermal transport phenomena, by presenting a direct and quantitative measurement of the Peltier component to electronic cooling and heating in graphene. Thanks to an architecture including nanoscale thermometers, we detected Peltier component modulation of up to 15 mK for currents of 20 μA at room temperature and observed a full reversal between Peltier cooling and heating for electron and hole regimes. This fundamental thermodynamic property is a complementary tool for the study of nanoscale thermoelectric transport in two-dimensional materials. PMID:27161186

  17. Simplified motional heating rate measurements of trapped ions

    SciTech Connect

    Epstein, R. J.; Seidelin, S.; Leibfried, D.; Wesenberg, J. H.; Bollinger, J. J.; Amini, J. M.; Blakestad, R. B.; Britton, J.; Home, J. P.; Itano, W. M.; Jost, J. D.; Knill, E.; Langer, C.; Ozeri, R.; Shiga, N.; Wineland, D. J.

    2007-09-15

    We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 {mu}m above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300{+-}30 s{sup -1} for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

  18. Time and Space Resolved Heat Transfer Measurements Under Nucleate Bubbles with Constant Heat Flux Boundary Conditions

    NASA Technical Reports Server (NTRS)

    Myers, Jerry G.; Hussey, Sam W.; Yee, Glenda F.; Kim, Jungho

    2003-01-01

    Investigations into single bubble pool boiling phenomena are often complicated by the difficulties in obtaining time and space resolved information in the bubble region. This usually occurs because the heaters and diagnostics used to measure heat transfer data are often on the order of, or larger than, the bubble characteristic length or region of influence. This has contributed to the development of many different and sometimes contradictory models of pool boiling phenomena and dominant heat transfer mechanisms. Recent investigations by Yaddanapyddi and Kim and Demiray and Kim have obtained time and space resolved heat transfer information at the bubble/heater interface under constant temperature conditions using a novel micro-heater array (10x10 array, each heater 100 microns on a side) that is semi-transparent and doubles as a measurement sensor. By using active feedback to maintain a state of constant temperature at the heater surface, they showed that the area of influence of bubbles generated in FC-72 was much smaller than predicted by standard models and that micro-conduction/micro-convection due to re-wetting dominated heat transfer effects. This study seeks to expand on the previous work by making time and space resolved measurements under bubbles nucleating on a micro-heater array operated under constant heat flux conditions. In the planned investigation, wall temperature measurements made under a single bubble nucleation site will be synchronized with high-speed video to allow analysis of the bubble energy removal from the wall.

  19. Design of experiments for measuring heat-transfer coefficients with a lumped-parameter calorimeter

    NASA Technical Reports Server (NTRS)

    Vanfossen, G. J., Jr.

    1975-01-01

    A theoretical investigation was conducted to determine optimum experimental conditions for using a lumped-parameter calorimeter to measure heat-transfer coefficients and heating rates. A mathematical model of the transient temperature response of the calorimeter was used with the measured temperature response to predict the heat-transfer coefficient and the rate of heating. A sensitivity analysis was used to determine the optimum transient experiment for simultaneously measuring the heat addition during heating and the convective heat-transfer coefficient during heating and cooling of a lumped-parameter calorimeter. Optimum experiments were also designed for measuring the convective heat-transfer coefficient during both heating and cooling and cooling only.

  20. Measuring personal heat exposure in an urban and rural environment.

    PubMed

    Bernhard, Molly C; Kent, Shia T; Sloan, Meagan E; Evans, Mary B; McClure, Leslie A; Gohlke, Julia M

    2015-02-01

    Previous studies have linked heat waves to adverse health outcomes using ambient temperature as a proxy for estimating exposure. The goal of the present study was to test a method for determining personal heat exposure. An occupationally exposed group (urban groundskeepers in Birmingham, AL, USA N=21), as well as urban and rural community members from Birmingham, AL (N=30) or west central AL (N=30) wore data logging temperature and light monitors clipped to the shoe for 7 days during the summer of 2012. We found that a temperature monitor clipped to the shoe provided a comfortable and feasible method for recording personal heat exposure. Ambient temperature (°C) recorded at the nearest weather station was significantly associated with personal heat exposure [β 0.37, 95%CI (0.35, 0.39)], particularly in groundskeepers who spent more of their total time outdoors [β 0.42, 95%CI (0.39, 0.46)]. Factors significantly associated with lower personal heat exposure include reported time indoors [β -2.02, 95%CI (-2.15, -1.89)], reported income>20K [β -1.05, 95%CI (-1.79, -0.30)], and measured % body fat [β -0.07, 95%CI (-0.12, -0.02)]. There were significant associations between income and % body fat with lower indoor and nighttime exposures, but not with outdoor heat exposure, suggesting modifications of the home thermal environment play an important role in determining overall heat exposure. Further delineation of the effect of personal characteristics on heat exposure may help to develop targeted strategies for preventing heat-related illness. PMID:25617601

  1. Measuring personal heat exposure in an urban and rural environment

    PubMed Central

    Bernhard, Molly C; Kent, Shia T; Sloan, Meagan E; Evans, Mary B; McClure, Leslie A; Gohlke, Julia M

    2014-01-01

    Previous studies have linked heat waves to adverse health outcomes using ambient temperature as a proxy for estimating exposure. The goal of the present study was to test a method for determining personal heat exposure. An occupationally exposed group (urban groundskeepers in Birmingham, AL, USA N=21), as well as urban and rural community members from Birmingham, AL (N=30) or west central AL (N=30) wore data logging temperature and light monitors clipped to the shoe for 7 days during the summer of 2012. We found that a temperature monitor clipped to the shoe provided a comfortable and feasible method for recording personal heat exposure. Ambient temperature (°C) recorded at the nearest weather station was significantly associated with personal heat exposure [β 0.37, 95%CI (0.35, 0.39)], particularly in groundskeepers who spent more of their total time outdoors [β 0.42, 95%CI (0.39, 0.46)]. Factors significantly associated with lower personal heat exposure include reported time indoors [β −2.02, 95%CI (−2.15, −1.89)], reported income > 20K [β −1.05, 95%CI (−1.79, −0.30)], and measured % body fat [β −0.07, 95%CI (−0.12, −0.02)]. There were significant associations between income and % body fat with lower indoor and nighttime exposures, but not with outdoor heat exposure, suggesting modifications of the home thermal environment play an important role in determining overall heat exposure. Further delineation of the effect of personal characteristics on heat exposure may help to develop targeted strategies for preventing heat-related illness. PMID:25617601

  2. Measurement of heat pump processes induced by laser radiation

    NASA Technical Reports Server (NTRS)

    Garbuny, M.; Henningsen, T.

    1983-01-01

    A series of experiments was performed in which a suitably tuned CO2 laser, frequency doubled by a Tl3AsSe37 crystal, was brought into resonance with a P-line or two R-lines in the fundamental vibration spectrum of CO. Cooling or heating produced by absorption in CO was measured in a gas-thermometer arrangement. P-line cooling and R-line heating could be demonstrated, measured, and compared. The experiments were continued with CO mixed with N2 added in partial pressures from 9 to 200 Torr. It was found that an efficient collisional resonance energy transfer from CO to N2 existed which increased the cooling effects by one to two orders of magnitude over those in pure CO. Temperature reductions in the order of tens of degrees Kelvin were obtained by a single pulse in the core of the irradiated volume. These measurements followed predicted values rather closely, and it is expected that increase of pulse energies and durations will enhance the heat pump effects. The experiments confirm the feasibility of quasi-isentropic engines which convert laser power into work without the need for heat rejection. Of more immediate potential interest is the possibility of remotely powered heat pumps for cryogenic use, such applications are discussed to the extent possible at the present stage.

  3. Simultaneous specific heat and thermal conductivity measurement of individual nanostructures

    NASA Astrophysics Data System (ADS)

    Zheng, Jianlin; Wingert, Matthew C.; Moon, Jaeyun; Chen, Renkun

    2016-08-01

    Fundamental phonon transport properties in semiconductor nanostructures are important for their applications in energy conversion and storage, such as thermoelectrics and photovoltaics. Thermal conductivity measurements of semiconductor nanostructures have been extensively pursued and have enhanced our understanding of phonon transport physics. Specific heat of individual nanostructures, despite being an important thermophysical parameter that reflects the thermodynamics of solids, has remained difficult to characterize. Prior measurements were limited to ensembles of nanostructures in which coupling and sample inhomogeneity could play a role. Herein we report the first simultaneous specific heat and thermal conductivity measurements of individual rod-like nanostructures such as nanowires and nanofibers. This technique is demonstrated by measuring the specific heat and thermal conductivity of single ∼600–700 nm diameter Nylon-11 nanofibers (NFs). The results show that the thermal conductivity of the NF is increased by 50% over the bulk value, while the specific heat of the NFs exhibits bulk-like behavior. We find that the thermal diffusivity obtained from the measurement, which is related to the phonon mean free path (MFP), decreases with temperature, indicating that the intrinsic phonon Umklapp scattering plays a role in the NFs. This platform can also be applied to one- and two- dimensional semiconductor nanostructures to probe size effects on the phonon spectra and other transport physics.

  4. Coupling Vector-host Dynamics with Weather Geography and Mitigation Measures to Model Rift Valley Fever in Africa

    PubMed Central

    McMahon, B.H.; Manore, C.A.; Hyman, J.M.; LaBute, M.X.; Fair, J.M.

    2015-01-01

    We present and characterize a multi-host epidemic model of Rift Valley fever (RVF) virus in East Africa with geographic spread on a network, rule-based mitigation measures, and mosquito infection and population dynamics. Susceptible populations are depleted by disease and vaccination and are replenished with the birth of new animals. We observe that the severity of the epidemics is strongly correlated with the duration of the rainy season and that even severe epidemics are abruptly terminated when the rain stops. Because naturally acquired herd immunity is established, total mortality across 25 years is relatively insensitive to many mitigation approaches. Strong reductions in cattle mortality are expected, however, with sufficient reduction in population densities of either vectors or susceptible (ie. unvaccinated) hosts. A better understanding of RVF epidemiology would result from serology surveys to quantify the importance of herd immunity in epidemic control, and sequencing of virus from representative animals to quantify the realative importance of transportation and local reservoirs in nucleating yearly epidemics. Our results suggest that an effective multi-layered mitigation strategy would include vector control, movement control, and vaccination of young animals yearly, even in the absence of expected rainfall. PMID:25892858

  5. Measurement of the Convective Heat-Transfer Coefficient

    ERIC Educational Resources Information Center

    Conti, Rosaria; Gallitto, Aurelio Agliolo; Fiordilino, Emilio

    2014-01-01

    We propose an experiment for investigating how objects cool down toward the thermal equilibrium with their surroundings. We describe the time dependence of the temperature difference of the cooling objects and the environment with an exponential decay function. By measuring the thermal constant t, we determine the convective heat-transfer…

  6. Heat transport measurements in turbulent rotating Rayleigh-Benard convection

    SciTech Connect

    Ecke, Robert E; Liu, Yuanming

    2008-01-01

    We present experimental heat transport measurements of turbulent Rayleigh-Benard convection with rotation about a vertical axis. The fluid, water with Prandtl number ({sigma}) about 6, was confined in a cell which had a square cross section of 7.3 cm x 7.3 cm and a height of 9.4 cm. Heat transport was measured for Rayleigh numbers 2 x 10{sup 5} < Ra < 5 x 10{sup 8} and Taylor numbers 0 < Ta < 5 x 10{sup 9}. We show the variation of normalized heat transport, the Nusselt number, at fixed dimensional rotation rate {Omega}{sub D}, at fixed Ra varying Ta, at fixed Ta varying Ra, and at fixed Rossby number Ro. The scaling of heat transport in the range 10{sup 7} to about 10{sup 9} is roughly 0.29 with a Ro dependent coefficient or equivalently is also well fit by a combination of power laws of the form a Ra{sup 1/5} + b Ra{sup 1/3} . The range of Ra is not sufficient to differentiate single power law or combined power law scaling. The overall impact of rotation on heat transport in turbulent convection is assessed.

  7. Scanning measurement of Seebeck coefficient of a heated sample

    DOEpatents

    Snyder, G. Jeffrey; Iwanaga, Shiho

    2016-04-19

    A novel scanning Seebeck coefficient measurement technique is disclosed utilizing a cold scanning thermocouple probe tip on heated bulk and thin film samples. The system measures variations in the Seebeck coefficient within the samples. The apparatus may be used for two dimensional mapping of the Seebeck coefficient on the bulk and thin film samples. This technique can be utilized for detection of defective regions, as well as phase separations in the sub-mm range of various thermoelectric materials.

  8. Measuring Response Of Propellant To Oscillatory Heat Flux

    NASA Technical Reports Server (NTRS)

    Strand, Leon D.; Schwartz, Ken; Burns, Shawn P.

    1990-01-01

    Apparatus for research in combustion of solid propellants measures oscillatory response of rate of burning to oscillating thermal radiation from modulated CO2 laser. Determines response to rate of burning to equivalent oscillation in pressure. Rod of propellant mounted in burner assembly including waveguide at one end and infrared window at other end. Microwave Doppler velocimeter measures motion of combustion front. Microwave, laser-current, and heat-flux signals processed into and recorded in forms useful in determining desired response of propellent.

  9. Compressibility measurements of gases using externally heated pressure vessels.

    NASA Technical Reports Server (NTRS)

    Presnall, D. C.

    1971-01-01

    Most of the data collected under conditions of high temperature and pressure have been determined using a thick-walled bomb of carefully measured and fixed volume which is externally heated by an electric furnace or a thermostatically controlled bath. There are numerous variations on the basic method depending on the pressure-temperature range of interest, and the particular gas or gas mixture being studied. The construction and calibration of the apparatus is discussed, giving attention to the pressure vessel, the volume of the bomb, the measurement of pressure, the control and measurement of temperature, and the measurement of the amount and composition of gas in the bomb.

  10. Tomato yellow leaf curl virus infection mitigates the heat stress response of plants grown at high temperatures

    PubMed Central

    Ghandi, Anfoka; Adi, Moshe; Lilia, Fridman; Linoy, Amrani; Or, Rotem; Mikhail, Kolot; Mouhammad, Zeidan; Henryk, Czosnek; Rena, Gorovits

    2016-01-01

    Cultured tomatoes are often exposed to a combination of extreme heat and infection with Tomato yellow leaf curl virus (TYLCV). This stress combination leads to intense disease symptoms and yield losses. The response of TYLCV-susceptible and resistant tomatoes to heat stress together with viral infection was compared. The plant heat-stress response was undermined in TYLCV infected plants. The decline correlated with the down-regulation of heat shock transcription factors (HSFs) HSFA2 and HSFB1, and consequently, of HSF-regulated genes Hsp17, Apx1, Apx2 and Hsp90. We proposed that the weakened heat stress response was due to the decreased capacity of HSFA2 to translocate into the nuclei of infected cells. All the six TYLCV proteins were able to interact with tomato HSFA2 in vitro, moreover, coat protein developed complexes with HSFA2 in nuclei. Capturing of HSFA2 by viral proteins could suppress the transcriptional activation of heat stress response genes. Application of both heat and TYLCV stresses was accompanied by the development of intracellular large protein aggregates containing TYLCV proteins and DNA. The maintenance of cellular chaperones in the aggregated state, even after recovery from heat stress, prevents the circulation of free soluble chaperones, causing an additional decrease in stress response efficiency. PMID:26792235