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Sample records for haiged mandlid minema

  1. Meltwater runoff from Haig Glacier, Canadian Rocky Mountains, 2002-2013

    NASA Astrophysics Data System (ADS)

    Marshall, S. J.

    2014-07-01

    Observations of high-elevation meteorological conditions, glacier mass balance, and glacier runoff are sparse in western Canada and the Canadian Rocky Mountains, leading to uncertainty about the importance of glaciers to regional water resources. This needs to be quantified so that the impacts of ongoing glacier recession can be evaluated with respect to alpine ecology, hydroelectric operations, and water resource management. I assess the seasonal evolution of glacier runoff in an alpine watershed on the continental divide in the Canadian Rocky Mountains. Analysis is based on meteorological, snowpack and surface energy balance data collected at Haig Glacier from 2002-2013. The study area is one of several glacierized headwaters catchments of the Bow River, which flows eastward to provide an important supply of water to the Canadian prairies. Annual specific discharge from snow- and ice-melt on Haig Glacier averaged 2350 mm water equivalent (w.e.) from 2002-2013, with 42% of the runoff derived from melting of glacier ice and firn, i.e. water stored in the glacier reservoir. This is an order of magnitude greater than the annual specific discharge from non-glacierized parts of the Bow River basin. From 2002-2013, meltwater derived from the glacier storage was equivalent to 5-6% of the flow of the Bow River in Calgary in late summer and 2-3% of annual discharge. The basin is typical of most glacier-fed mountains rivers, where the modest and declining extent of glacierized area in the catchment limits the glacier contribution to annual runoff.

  2. Meltwater run-off from Haig Glacier, Canadian Rocky Mountains, 2002-2013

    NASA Astrophysics Data System (ADS)

    Marshall, S. J.

    2014-12-01

    Observations of high-elevation meteorological conditions, glacier mass balance, and glacier run-off are sparse in western Canada and the Canadian Rocky Mountains, leading to uncertainty about the importance of glaciers to regional water resources. This needs to be quantified so that the impacts of ongoing glacier recession can be evaluated with respect to alpine ecology, hydroelectric operations, and water resource management. In this manuscript the seasonal evolution of glacier run-off is assessed for an alpine watershed on the continental divide in the Canadian Rocky Mountains. The study area is a headwaters catchment of the Bow River, which flows eastward to provide an important supply of water to the Canadian prairies. Meteorological, snowpack, and surface energy balance data collected at Haig Glacier from 2002 to 2013 were analysed to evaluate glacier mass balance and run-off. Annual specific discharge from snow- and ice-melt on Haig Glacier averaged 2350 mm water equivalent from 2002 to 2013, with 42% of the run-off derived from melting of glacier ice and firn, i.e. water stored in the glacier reservoir. This is an order of magnitude greater than the annual specific discharge from non-glacierized parts of the Bow River basin. From 2002 to 2013, meltwater derived from the glacier storage was equivalent to 5-6% of the flow of the Bow River in Calgary in late summer and 2-3% of annual discharge. The basin is typical of most glacier-fed mountain rivers, where the modest and declining extent of glacierized area in the catchment limits the glacier contribution to annual run-off.

  3. Meltwater Runoff and Storage Based on Dielectric Properties of the Supraglacial Snowpack on Haig Glacier, Canadian Rocky Mountains.

    NASA Astrophysics Data System (ADS)

    Samimi, S.; Marshall, S. J.

    2015-12-01

    Meltwater refreezing and storage in the supraglacial snowpack can reduce and delay meltwater runoff on temperate alpine glaciers, but models of glacier runoff that are used to examine mass balance and glacier water resources do not generally account for this storage. Past studies on Haig Glacier in the Canadian Rocky Mountains show a consistent over-estimate of the amount of summer runoff from the glacier, based on modeled melt vs. measured discharge. We hypothesized that much of the 'missing runoff' was associated with overnight refreezing of meltwater that is ponded on the glacier surface and stored in pore space of the seasonal snowpack. Additional energy is required to melt this refrozen water each day, such that a large fraction of the meltwater that is generated on the glacier is 'recycled' water. To test this idea, we measured the temperature and meltwater content in the upper 40 cm of the supraglacial snowpack of Haig Glacier in spring and summer 2015. Thermistors and TDR probes were installed at 10-cm intervals at two sites in the glacier accumulation area. A Denoth meter was used to make point measurements for comparison with the TDR inferences of snowpack dielectric properties. These data are supplemented by automatic weather station data, used to calculate surface melt rates, and discharge measurements in the glacier outlet stream. We observed a strong diurnal cycle in snow water content, with the snowpack drying out overnight, but contrary to what we expected, there was negligible subsurface meltwater refreezing during our study. Overnight refreezing was restricted to a thin surface layer of the snowpack, while overnight drying was likely due to meltwater drainage to the snow-ice interface. We use our observations to calibrate and test a model of meltwater runoff from the glacier from summer 2015.

  4. A bold new future for public health or implementing the "Alexander Haig" idea.

    PubMed

    Mahan, C S

    2000-01-01

    An amalgam of effort by public health practitioners and academics is needed to attain the goal of public health taking charge of U.S. health care early in the new millenium. Numerous ideas for joint collaborations in service, research, and teaching are presented. Goals, quality improvement and reporting, customer satisfaction, and leadership training are developing strengths in the field that will help make rapid progress toward the goal. Oversight of health services by public health is essential to the development of a successful U.S. health system. PMID:10724696

  5. Putting Concepts and Constructs into Practice: A Reply to Cervone and Caldwell, Haig, Kane, Mislevy, and Rupp

    ERIC Educational Resources Information Center

    Markus, Keith A.

    2008-01-01

    The commentary has greatly enriched the discussion initiated by the three target articles. The distinction between constructs and concepts contributes to both the top-down and bottom-up aspects of the dialectic between measurement theory and practice. The distinction also illuminates the abstraction from observation to manifest variables. However,…

  6. Human neutrophil Fc receptor-mediated adhesion under flow: a hollow fibre model of intravascular arrest.

    PubMed

    D'Arrigo, C; Candal-Couto, J J; Greer, M; Veale, D J; Woof, J M

    1995-04-01

    Human polymorphonuclear cells (PMN) were found to adhere to a novel model of blood vessel wall-associated IgG. The internal surfaces of cellulose acetate hollow fibres, of comparable internal diameter to small blood vessels, were coated with normal serum human IgG, heat-aggregated IgG (HAIgG), laminin or fibrinogen. Under conditions of flow mimicking those in a small vessel, PMN were found to adhere markedly only to immunoglobulin-coated fibres. Arrest on HAIgG was inhibited by excess soluble IgG but not by bovine serum albumin (BSA), demonstrating that the adhesion was IgG-specific and presumably mediated by Fc gamma R on the PMN surface. Pre-adsorption of serum components onto HAIgG-coated fibres enhanced PMN arrest, due most probably to fixation of complement components by immobilized HAIgG, resulting in additional potential to entrap PMN via complement receptors such as CR3. Treatment of PMN with the regulatory neuropeptide substance P also enhanced adhesion to HAIgG-coated fibres and caused increased surface expression of Fc gamma RI, Fc gamma RII and Fc gamma RIII. A mouse cell line derived from L cells, hR4C6, stably transfected with human Fc gamma RII, was found to adhere under flow to HAIgG-coated fibres, whilst untransfected parent L cells did not. This adhesion was similarly inhibited by excess soluble IgG, confirming the capability of Fc gamma R to mediate cell arrest. The study strongly suggests that Fc gamma R may play an important role in intravascular PMN arrest and we speculate that in inflammatory diseases PMN may adhere via Fc gamma R to immobilized immunoglobulin on the vascular endothelium, with subsequent degranulation and tissue damage. PMID:7535210

  7. Scientific Symbiosis Represents the Mutual Benefit of Iteratively Adopting the Perspective of Realism and Instrumentalism

    ERIC Educational Resources Information Center

    Cacioppo, John T.; Berntson, Gary G.; Semin, Gu R.

    2005-01-01

    This article presents comments on "Psychology Needs Realism not Instrumentalism" by B. Haig, "Ontological and Epistemic Claims of Realism and Instrumentalism" by Lau and "The Scientific Denial of the Real and the Dialectic of Scientism and Humanism" by Ramey and Chrysikou which were all comments on the original article "Realism, Instrumentalism,…

  8. Physiological responses in potato plants under continuous irradiation

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1991-01-01

    The physiological responses of four potato (Solanum tuberosum L.) cultivars to continuous irradiation were determined in a controlled environment. Under a constant 18C and a constant photoperiod of 470 micromoles s-1 m-2 of photosynthetic photon flux, 'Denali' and 'Haig' grew well and produced large plant and tuber dry weights when harvested 56 days after transplanting. 'Kennebec' and 'Superior' were severely stunted, producing only 10% of the plant dry matter produced by 'Denali' and 'Haig'. The differences in leaf chlorophyll concentration and stomatal conductance were not consistent between these two groups of cultivars. The leaf net CO2 assimilation rates in 'Kennebec' and 'Superior' were lower, and intercellular CO2 partial pressures were higher than in 'Denali' and 'Haig'. These results indicate that inhibition of net CO2 assimilation in 'Kennebec' and 'Superior' was not due to a limiting amount of chlorophyll or to CO2 in the leaf tissues. Concentrations of starch in leaflets of 'Kennebec' and 'Superior' plants were only 10% of those in 'Denali' and 'Haig' plants, although soluble sugar concentrations were similar in the four cultivars. Therefore, the lower net CO2 assimilation rates in stunted 'Kennebec' and 'Superior' plants were not associated with an excess carbohydrate accumulation in the leaves.

  9. On Prototypes and Paradigm Shifts

    ERIC Educational Resources Information Center

    McGrath, Robert E.

    2009-01-01

    The author agrees with the editors of this informative series of articles (Haig & Borsboom, 2008) that the number of articles appearing in recent years questioning basic assumptions about psychosocial measurement instruments, such as their mathematical qualities and their potential as valid indicators, augurs well for serious reconsideration of…

  10. Treating the Pathology of Psychometrics: An Example from the Comprehension of Continuous Prose Text

    ERIC Educational Resources Information Center

    Kyngdon, Andrew

    2008-01-01

    Few would argue that psychology has been as successful as the natural sciences in constructing measurement systems, yet this has not tempered the near universal claim of psychological measurement. As Haig and Denny Borsboom note, the sustained nature of conceptual attacks from a small group of quantitative psychologists suggests a deep-seated…

  11. Utilization of potatoes for life support in space. V. Evaluation of cultivars in response to continuous light and high temperature

    NASA Technical Reports Server (NTRS)

    Tibbitts, T. W.; Cao, W.; Bennett, S. M.

    1992-01-01

    Twenty-four potato (Solanum tuberosum L.) cultivars from different regions of the world were evaluated in terms of their responses to continuous light (24 h photoperiod) and to high temperature (30 C) in two separate experiments under controlled environments. In each experiment, a first evaluation of the cultivars was made at day 35 after transplanting, at which time 12 cultivars exhibiting best growth and tuber initiation were selected. A final evaluation of the 12 cultivars was made after an additional 21 days of growth, at which time plant height, total dry weight, tuber dry weight, and tuber number were determined. In the continuous light evaluation, the 12 selected cultivars were Alaska 114, Atlantic, Bintje, Denali, Desiree, Haig, New York 81, Ottar, Rutt, Snogg, Snowchip, and Troll. In the high temperature evaluation, the 12 selected cultivars were Alpha, Atlantic, Bake King, Denali, Desiree, Haig, Kennebec, Norland, Russet Burbank, Rutt, Superior, and Troll. Among the cultivars selected under continuous irradiation, Desiree, Ottar, Haig, Rutt, Denali and Alaska showed the best potential for high productivity whereas New York 81 and Bintje showed the least production capability. Among the cultivars selected under high temperature, Rutt, Haig, Troll and Bake King had best performance whereas Atlantic, Alpha, Kennebec and Russet Burbank exhibited the least production potential. Thus, Haig and Rutt were the two cultivars that performed well under continuous irradiation and high temperature conditions, and could have maximum potential for adaptation to varying stress environments. These two cultivars may have the best potential for use in future space farming in which continuous light and/or high temperature conditions may exist. However, cultivar responses under combined conditions of continuous light and high temperature remains for further validation.

  12. Atmospheric deposition of sulfur and inorganic nitrogen in the Southern Canadian Rocky Mountains from seasonal snowpacks and bulk summer precipitation

    NASA Astrophysics Data System (ADS)

    Wasiuta, Vivian; Lafrenière, Melissa J.; Norman, Ann-Lise

    2015-04-01

    This study quantified atmospheric deposition of sulfur (S) and nitrogen (N) in the alpine of the Southern Canadian Rocky Mountains and evaluated loads relative to critical limits for ecologic effects on alpine ecosystems from N saturation and acidification. Deposition was evaluated by collecting seasonal snowpack and summer bulk precipitation samples along elevational transects in the alpine Haig Valley and given regional context using snowpack samples from six additional glacier sites. S and N deposition were evaluated in terms of two conceptual models. Model 1 representing deposition from emissions that are mainly distant and Model 2 representing deposition from a mixture of distant and local to regional emissions. Annual S and N (including ammonium (NH4+), nitrate (NO3-) and nitrite (NO2-)) deposition in the alpine Haig Valley was 0.74 ± 0.18 kg S ha-1 and 1.10 ± 0.18 kg N ha-1 yr-1, which is sufficiently high for the occurrence of detrimental ecologic effects related to N saturation in the most sensitive alpine ecosystems, but lower than the critical limit for acidification. Snowpack S and N deposition was consistent with well mixed air mainly from distant sources (Model 1), therefore indicating S and N were largely transported within the precipitating air mass and or picked up by the air mass in transit to the alpine Haig Valley. Relatively consistent deposition of S and N in seasonal glacier snowpacks at sites extending 210 km along the Continental Divide and 100 km west of the divide supports the interpretation that Model 1 describes deposition in alpine glacier snowpack. Similar deposition values for the highest site in the Haig Valley and the mean from the regional snowpack study indicate the highest site in the Haig Valley represents regional conditions of S and N deposition. Summer deposition of sulfate (SO42-) and ammonium (NH4+) was also consistent with dominantly distant emission sources (Model 1). In contrast there was enhanced transport and

  13. Thermomagnetic analysis of meterorites. 4: Ureilites

    NASA Technical Reports Server (NTRS)

    Rowe, M. W.; Herndon, J. M.; Larson, E. E.; Watson, D. E.

    1974-01-01

    Samples of all available ureilites have been analyzed thermomagnetically. For three of the six (Dyalpur, Goalpara and Havero) evidence was found for only low-nickel metallic-iron as the magnetic component and the (saturation magnetization vs, temperature) curves were reversible. In the Novo Urei ureilite, magnetite in addition to low-nickel metallic-iron was indicated and again the Js-T curve was reversible. For the two badly weathered ureilites, Dingo Pup Donga and North Haig, indication was also found that both initial magnetite and low-nickel metallic-iron were present. However, the Js-T curves were somewhat irreversible and the final saturation magnetization was 20% and 50% greater than initially for North Haig and Dingo Pup Donga, respectively. This behavior is interpreted to be the result of magnetite production from a secondary iron oxide during the experiment.

  14. Advances in Modelling of Valley Glaciers

    NASA Astrophysics Data System (ADS)

    Adhikari, Surendra

    For glaciological conditions typical of valley glaciers, the central idea of this research lies in understanding the effects of high-order mechanics and parameterizing these for simpler dynamical and statistical methods in glaciology. As an effective tool for this, I formulate a new brand of dynamical models that describes distinct physical processes of deformational flow. Through numerical simulations of idealized glacier domains, I calculate empirical correction factors to capture the effects of longitudinal stress gradients and lateral drag for simplified dynamical models in the plane-strain regime. To get some insights into real glacier dynamics, I simulate Haig Glacier in the Canadian Rocky Mountains. As geometric effects overshadow dynamical effects in glacier retreat scenarios, it appears that high-order physics are not very important for Haig Glacier, particularly for evaluating its fate. Indeed, high-order and reduced models all predict that Haig Glacier ceases to exist by about AD2080 under ongoing climate warming. This finding regarding the minimal role of high-order physics may not be broadly valid, as it is not true in advance scenarios at Haig Glacier and it may not be representative of other glaciological settings. Through a 'bulk' parameterization of high-order physics, geometric and climatic settings, sliding conditions, and transient effects, I also provide new insights into the volume-area relation, a widely used statistical method for estimating glacier volume. I find a steady-state power-law exponent of 1:46, which declines systematically to 1:38 after 100 years of sustained retreat, in good accord with the observations. I recommend more accurate scaling relations through characterization of individual glacier morphology and degree of climatic disequilibrium. This motivates a revision of global glacier volume estimates, of some urgency in sea level rise assessments.

  15. Prostaglandin E2 modulation of rheumatoid factor synthesis.

    PubMed

    Alvarellos, A; Lipsky, P E; Jasin, H E

    1988-12-01

    We examined the influence of prostaglandin E2 (PGE2) on the in vitro synthesis of rheumatoid factor (RF) by purified human B and T lymphocytes stimulated with Staphylococcus aureus Cowan 1 or pokeweed mitogen (PWM). Supernatants were assayed for total IgM and RF. PGE2 at concentrations of 10(-7) M to 10(-9) M significantly inhibited RF and IgM secretion stimulated by S aureus Cowan 1, a cross-linker of B cell surface Ig. The magnitude of inhibition of RF production was significantly greater than that of total IgM at low PGE2 concentrations (P less than 0.05). In contrast, PWM-stimulated cultures were only minimally inhibited by PGE2 at all concentrations tested. Since cross-linking of surface Ig renders B cells more susceptible to inhibition by PGE2, heat-aggregated IgG (HAIgG) was added to the PWM-stimulated cultures in an attempt to increase the sensitivity of precursors of RF-secreting cells to the inhibitory effects of PGE2. Addition of HAIgG markedly increased PGE2-mediated inhibition of RF synthesis without significantly affecting IgM production. Inhibition could not be overcome by the addition of soluble T helper cell factors, indicating that PGE2-mediated suppression was not the result of an inhibitory action of T helper cells. When lymphocytes from patients with rheumatoid arthritis were examined, HAIgG was found to be unable to induce sensitivity to PGE2-mediated inhibition of responsiveness. These results suggest that down-regulation of RF synthesis requires both cross-linking of surface Ig and the influence of PGE2. Abnormalities in this immunoregulatory mechanism may explain the ongoing production of RF in patients with rheumatoid arthritis. PMID:3264162

  16. [Morphology of the first zoea of the marine crabs Petrolisthes haigae and P. nobilii (Decapoda: Porcellanidae)].

    PubMed

    Hernández, Gonzalo; Bolaños, Juan; Magán, Isabel; Graterol, Karen

    2007-01-01

    The porcellanid crabs Petrolisthes haigae Chace 1962, and P nobilii Haig 1960, are shallow-water species distributed along the tropical Eastern Pacific shores. Larvae of both species from eight and four females, collected at Taboga and Naos Islands, respectively, were hatched in the laboratory. First zoeal stages of these species are described and illustrated for the first time and compared to previously first zoeae of other congeneric species from western Panama. Characters of the first zoeae of both species most closely agree with those Osawa's (2002) Group 4 of larvae. PMID:19086392

  17. Identification of a Common R-Chondrite Impactor on the Ureilite Parent Body

    NASA Technical Reports Server (NTRS)

    Downes, H.; Mittlefehldt, D. W.

    2006-01-01

    Polymict ureilites are brecciated ultramafic meteorites that contain a variety of single mineral and lithic clasts. They represent the surface debris from a small, differentiated asteroid. We are continuing a detailed petrological study of several polymict ureilites including EET 87720, EET 83309 and FRO93008 (from Antarctica), North Haig, Nilpena (Australia), DaG 976, DaG 999, DaG 1000 and DaG 1023 (Libya). The latter four stones are probably paired. Clast sizes can be 10 mm in diameter, so a thin-section can consist of a single lithic clast.

  18. Fluorescent accessory phases in the carbonaceous matrix of ureilites

    NASA Technical Reports Server (NTRS)

    Berkley, J. L.; Taylor, G. J.; Keil, K.; Healey, J. T.

    1978-01-01

    The carbonaceous matrix of ureilite meteorites (C-bearing olivine-pigeonite achondrites) contain abundant minute phases that emit a multicolored fluorescence under electron bombardment. These include NaCl and KCl, found in all seven ureilites studied, high-Si glass with pyroxene and chlorapatite quench crystals in North Haig, an unidentified high-Ca-Al-Cl phase in Novo Urei, and possibly free SiO2 in Novo Urei and Dingo Pup Donga. The origin of these phases is uncertain but some, especially chlorides and glass, may represent residual postcumulus materials precipitated from a late-stage interstitial liquid during the igneous phase of ureilite history.

  19. Genetic Applications in Avian Conservation

    USGS Publications Warehouse

    Haig, Susan M.; Bronaugh, Whitcomb M.; Crowhurst, Rachel S.; D'Elia, Jesse; Eagles-Smith, Collin A.; Epps, Clinton W.; Knaus, Brian; Miller, Mark P.; Moses, Michael L.; Oyler-McCance, Sara; Robinson, W. Douglas; Sidlauskas, Brian

    2011-01-01

    A fundamental need in conserving species and their habitats is defining distinct entities that range from individuals to species to ecosystems and beyond (Table 1; Ryder 1986, Moritz 1994, Mayden and Wood 1995, Haig and Avise 1996, Hazevoet 1996, Palumbi and Cipriano 1998, Hebert et al. 2004, Mace 2004, Wheeler et al. 2004, Armstrong and Ball 2005, Baker 2008, Ellis et al. 2010, Winker and Haig 2010). Rapid progression in this interdisciplinary field continues at an exponential rate; thus, periodic updates on theory, techniques, and applications are important for informing practitioners and consumers of genetic information. Here, we outline conservation topics for which genetic information can be helpful, provide examples of where genetic techniques have been used best in avian conservation, and point to current technical bottlenecks that prevent better use of genomics to resolve conservation issues related to birds. We hope this review will provide geneticists and avian ecologists with a mutually beneficial dialogue on how this integrated field can solve current and future problems.

  20. Nature of the carbon and sulfur phases and inorganic gases in the Kenna ureilite

    NASA Technical Reports Server (NTRS)

    Gibson, E. K., Jr.

    1976-01-01

    Abundances of carbon and sulfur in the Kenna ureilite are 2.219 plus or minus 0.060 wt. % C and 0.179 plus or minus 0.008 wt. % S. Secondary carbonates resulting from terrestrial weathering account for 0.25 plus or minus 0.02 wt. % C. No hydrocarbons were detected during gas release measurements. Most of the carbon is in graphite, diamond, or lonsdaleite. The sample of Kenna contained 0.95 plus or minus 0.05 wt.% H2O. Total carbon and sulfur measurements were made on three additional ureilites: Havero, Dingo Pup Donga, and North Haig. Ureilite carbon abundances are similar to those of C-2 chondrites, whereas sulfur abundances are a factor of 10 less than C-2 chondrites and ordinary chondrites. The elemental abundances, ratios, and phases present in the ureilites rule out a direct genetic relationship between the ureilites and the carbonaceous chondrites.

  1. Aluminum-26 in meteorites. VII - Ureilites, their unique radiation history.

    NASA Technical Reports Server (NTRS)

    Wilkening, L. L.; Herman, G. F.; Anders, E.

    1973-01-01

    Cosmogenic Al-26 activities have been measured by gamma-gamma coincidence counting in the three ureilites which had not previously been studied. The values in dpm/kg are: Dingo Pup Donga, 38.4 plus or minus 2.4; North Haig, 39.3 plus or minus 4.8; Dyalpur, 55.8 plus or minus 4.8. Five of the six known ureilites thus have lower Al-26 contents, 63 per cent to 77 per cent, than the calculated saturation values, in marked contrast to most other stony meteorites. This cannot be attributed to short cosmic ray exposure ages. The most likely explanation is that the ureilites had much smaller or much larger orbits than all other stony meteorites.

  2. Oil diplomacy: the Atlantic nations in the oil crisis of 1978-79

    SciTech Connect

    Not Available

    1980-01-01

    Six essays examine how the US, Western Europe, and Japan have handled their common energy problems and to what extent their traditional cooperation has been enhanced or diminished by the OPEC actions. They explore the interdependencies of the developed countries, along with the strains that the energy crisis has placed on the search for common solutions. An introduction by Alexander Haig is followed by essays titled: The Permanent Crisis: Change in the World Oil System; The American Response: On-the-Job Training; Western Europe: A Fragmented Response to a Fragmenting Order; The West in Concert: A Very Complex Score; Politics of Dependence: Western Europe and the Arab-Israeli Conflict; Oil on Troubled Waters: The Industrial World and the OPEC; Oil and Money: A Note on the Western Financial Community; and Getting Out of the Crisis: excerpt of interviews. 2 tables. (DCK)

  3. Psychometrically appropriate assessment of afocal optics by measurement of the Strehl intensity ratio

    NASA Astrophysics Data System (ADS)

    Haig, Nigel D.; Williams, T. L.

    1995-04-01

    Several different performance criteria have been proposed for assessing the quality of visual afocal sights. Earlier research by one of the authors (Haig) has shown that a high degree of correlation exists between a subjective assessment of performance and the Strehl intensity ratio of the optical system. We discuss some of the problems in choosing an objective performance criterion for visual sights and describe equipment that has been developed for measuring the line Strehl ratio of binoculars, both on and off axes. The equipment can be modified for testing other types of visual sight. It can also be used for measuring several additional performance parameters such as the modulation transfer function, transmission, and field curvature.

  4. A new distinctive species of pagurid hermit crab (Crustacea: Decapoda: Anomura) from Japan.

    PubMed

    Komai, T; Osawa, M

    2001-12-01

    A new species of pagurid hermit crab, Pagurus decimbranchiae, is described and illustrated based on 20 specimens collected from shallow waters of the Pacific coast of Japan ranging from Boso Peninsula to Tanegashima Island. It is quite distinctive in having the rudimentary arthrobranch on the third maxilliped represented by a single bud, however close morphological similarity is found between the new species and P. moluccensis Haig and Ball. Comparisons are also made among other species, including P. boriaustraliensis Morgan, P. sp. cf. boriaustraliensis sensu Rahayu and Komai (2000) and the members of the P. anachoretus group. The present generic assignment of the new species should be considered provisional, as more extensive study is needed to investigate phylogenetic relationships of the new species and the other species of Pagurus. PMID:11911085

  5. Deposition of Sulphate and Nitrogen in Alpine Precipitation of the Southern Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Wasiuta, V. L.; Lafreniere, M. J.

    2011-12-01

    Atmospheric nitrogen (N) and sulphur (S) are the main contributors to acid precipitation which causes regionally persistent ecological problems. Enhanced deposition of reactive N, mainly as nitrate (NO3-) and ammonium (NH4+), also contributes to major ecological problems associated with ecosystem N saturation. Alpine ecosystems, which are generally nutrient poor and exist under extreme climatic conditions, are sensitive to environmental and climatic stressors. Studies in the USA Rocky Mountains and European Alps have shown alpine ecosystems have a particularly sensitivity to enhanced deposition of reactive N and can show ecologically destructive responses at relatively low levels of N deposition. However, evaluation of atmospheric sulphur and nitrogen deposition in mid latitude alpine Western Canada has been initiated only very recently and at only a few locations. There is little comprehension of current atmospheric flux to high altitudes or the importance of contributions from major emission sources This work quantifies the atmospheric deposition of SO42- NH4+ and NO3- to a remote alpine site in the Southern Canadian Rocky Mountains by characterizing alpine precipitation. The effect of elevation and aspect on deposition are assessed using sampling sites along elevational transects in the adjacent Haig and Robertson Valleys. Seasonal variations in deposition of SO42- NH4+ and NO3- are evaluated using the autumn, winter, and spring precipitation accumulated in the seasonal snowpack at glacial and fore glacial locations, along with collected bulk summer precipitation. Preliminary results show lower precipitation volumes, which are associated with higher SO42- and NH4+ loads, in the north west facing Robertson Valley than the south east facing Haig Glacier. However trends in deposition of SO42- NH4+ and NO3- with elevation and aspect are inconsistent over the 2008-2009 and 2009-2010 snow accumulation seasons, and 2010 bulk summer precipitation seasons that were

  6. Paleomagnetism of Silver Island, Keweenaw Peninsula, Michigan: Additional Support (?) for the Primary Curvature of the MCR

    NASA Astrophysics Data System (ADS)

    Diehl, J. F.; Durant, A. J.; Schepke, C.

    2009-05-01

    Silver Island lies between Eagle Harbor and Copper Harbor on the NW coastline of the Keweenaw Peninsula, Michigan. The island consists of a series of basaltic lava flows which dip to the north-northwest (356°) at an angle of approximately 38°. These flows constitute part of the Lake Shore Traps (LST), a series of interbedded lava flows within the Copper Harbor Conglomerate (CHC). The LST represent the youngest eruptive material associated with the 1.1 Ga Mid-Continent Rift (MCR). The most recent paleomagnetic study (now 15 years old) on the Lakeshore Traps (LST) defined three distinct directional clusters. Each cluster of directions corresponded to a different stratigraphic package of the LST within the CHC and all have extremely low between-site dispersion (s ˜ 4°) suggesting rather rapid emplacement of the LST packages. Consequently, each cluster has its own unique direction of magnetization. Since the lower two LST packages crop out along the coast line of the Peninsula with different structural trends, an opportunity was presented to test the conclusions of Hnat et al. (2006) that the curvature of the MCR was primary. To that end nine lava flows were sampled on Silver Island and their mean direction compared to the equivalent mean from lava flows sampled by Diehl and Haig (1994) from the tip of the Keweenaw Peninsula (upper lava flows of the Middle LST) which have an entirely different structural trend. Characteristic directions of magnetization of the Silver Island lava flows were isolated either using alternating field, thermal or a combination of both. The mean direction of magnetization for the nine sites is: D = 277.7°, I = 46.9°, α95 = 3.0°, k = 292.5. The mean direction recalculated from the Diehl and Haig study is: D = 277.8°, I = 40.6°, α95 = 2.9°, k = 315.7. Although the declinations of the two means are identical, interestingly the two means are statistically distinct at the 95% confidence level. Fold tests were inconclusive. Nevertheless

  7. Comparisons of likelihood and machine learning methods of individual classification

    USGS Publications Warehouse

    Guinand, B.; Topchy, A.; Page, K.S.; Burnham-Curtis, M. K.; Punch, W.F.; Scribner, K.T.

    2002-01-01

    “Assignment tests” are designed to determine population membership for individuals. One particular application based on a likelihood estimate (LE) was introduced by Paetkau et al. (1995; see also Vásquez-Domínguez et al. 2001) to assign an individual to the population of origin on the basis of multilocus genotype and expectations of observing this genotype in each potential source population. The LE approach can be implemented statistically in a Bayesian framework as a convenient way to evaluate hypotheses of plausible genealogical relationships (e.g., that an individual possesses an ancestor in another population) (Dawson and Belkhir 2001;Pritchard et al. 2000; Rannala and Mountain 1997). Other studies have evaluated the confidence of the assignment (Almudevar 2000) and characteristics of genotypic data (e.g., degree of population divergence, number of loci, number of individuals, number of alleles) that lead to greater population assignment (Bernatchez and Duchesne 2000; Cornuet et al. 1999; Haig et al. 1997; Shriver et al. 1997; Smouse and Chevillon 1998). Main statistical and conceptual differences between methods leading to the use of an assignment test are given in, for example,Cornuet et al. (1999) and Rosenberg et al. (2001). Howeve

  8. The evolution of genomic imprinting: theories, predictions and empirical tests

    PubMed Central

    Patten, M M; Ross, L; Curley, J P; Queller, D C; Bonduriansky, R; Wolf, J B

    2014-01-01

    The epigenetic phenomenon of genomic imprinting has motivated the development of numerous theories for its evolutionary origins and genomic distribution. In this review, we examine the three theories that have best withstood theoretical and empirical scrutiny. These are: Haig and colleagues' kinship theory; Day and Bonduriansky's sexual antagonism theory; and Wolf and Hager's maternal–offspring coadaptation theory. These theories have fundamentally different perspectives on the adaptive significance of imprinting. The kinship theory views imprinting as a mechanism to change gene dosage, with imprinting evolving because of the differential effect that gene dosage has on the fitness of matrilineal and patrilineal relatives. The sexual antagonism and maternal–offspring coadaptation theories view genomic imprinting as a mechanism to modify the resemblance of an individual to its two parents, with imprinting evolving to increase the probability of expressing the fitter of the two alleles at a locus. In an effort to stimulate further empirical work on the topic, we carefully detail the logic and assumptions of all three theories, clarify the specific predictions of each and suggest tests to discriminate between these alternative theories for why particular genes are imprinted. PMID:24755983

  9. Temperature cycling periods affect growth and tuberization in potatoes under continuous irradiation

    NASA Technical Reports Server (NTRS)

    Cao, W.; Tibbitts, T. W.

    1992-01-01

    Plants of the potato (Solanum tuberosum L.) cultivars Denali, Norland, Haig and Kennebec were grown for 42 days under three temperature cycling periods (thermoperiods) with continuous irradiation in two repeated experiments to help determine if temperature cycling might be varied to optimize tuber development of potatoes in controlled environments. Thermoperiods of 6/6 hours, 12/12 hours and 24/24 hours were established with the same temperature change of 22/14C and same controlled vapor pressure deficit of 0.60 kPa. The thermoperiod of 24/24 hours significantly promoted tuber initiation but slowed tuber enlargement in all four cultivars, compared to the thermoperiods of 6/6 hours and 12/12 hours. Denali' produced the highest tuber and total dry weights under the 6/6 hours thermoperiod. Kennebec' produced the highest tuber dry weight under the 12/12 hours thermoperiod. Thermoperiods had no significant effect on shoot and root dry weights of any cultivars. The major effect of thermoperiods was on initiation and enlargement of tubers.

  10. An experiment to fly on mission STS-93 is prepared at Life Sciences Building, CCAS

    NASA Technical Reports Server (NTRS)

    1999-01-01

    In the KSC Life Sciences Building, Hangar L, Cape Canaveral Air Station, Dr. Haig Keshishian checks fruit fly larvae in a petri dish. The larvae are part of an experiment that is a secondary payload on mission STS-93. The experiment will examine the effects of microgravity and space flight on the development of neural connections between specific motor neurons and their targets in muscle fibers. Dr. Keshishian, from Yale University, is the principle investigator for the experiment. The larvae will be contained in incubators that are part of a Commercial Generic Bioprocessing Apparatus (CGBA), which can start bioprocessing reactions by mixing or heating a sample and can also initiate multiple-step, sequential reactions in a technique called phased processing. The primary payload of mission STS-93 is the Chandra X-ray Observatory, which will allow scientists from around the world to see previously invisible black holes and high- temperature gas clouds, giving the observatory the potential to rewrite the books on the structure and evolution of our universe. The target launch date for STS-93 is July 9, aboard Space Shuttle Columbia, from Launch Pad 39B.

  11. The evolution of genomic imprinting: theories, predictions and empirical tests.

    PubMed

    Patten, M M; Ross, L; Curley, J P; Queller, D C; Bonduriansky, R; Wolf, J B

    2014-08-01

    The epigenetic phenomenon of genomic imprinting has motivated the development of numerous theories for its evolutionary origins and genomic distribution. In this review, we examine the three theories that have best withstood theoretical and empirical scrutiny. These are: Haig and colleagues' kinship theory; Day and Bonduriansky's sexual antagonism theory; and Wolf and Hager's maternal-offspring coadaptation theory. These theories have fundamentally different perspectives on the adaptive significance of imprinting. The kinship theory views imprinting as a mechanism to change gene dosage, with imprinting evolving because of the differential effect that gene dosage has on the fitness of matrilineal and patrilineal relatives. The sexual antagonism and maternal-offspring coadaptation theories view genomic imprinting as a mechanism to modify the resemblance of an individual to its two parents, with imprinting evolving to increase the probability of expressing the fitter of the two alleles at a locus. In an effort to stimulate further empirical work on the topic, we carefully detail the logic and assumptions of all three theories, clarify the specific predictions of each and suggest tests to discriminate between these alternative theories for why particular genes are imprinted. PMID:24755983

  12. Utilization of white potatoes in CELSS.

    PubMed

    Tibbitts, T W; Bennett, S M; Morrow, R C; Bula, R J

    1989-01-01

    Potatoes (Solanum tuberosum) have a strong potential as a useful crop species in a functioning CELSS. The cultivar Denali has produced 37.5 g m-2 d-1 when grown for 132 days with the first 40 days under a 12-h photoperiod and a light:dark temperature cycle of 20 degrees C:16 degrees C, and then 92 days under continuous irradiance and a temperature of 16 degrees C. Irradiance was at 725 micromoles m-2 s-1 PPF and carbon dioxide at 1000 micromoles mol-1. The dried tubers had 82% carbohydrates, 9% protein and 0.6% fat. Other studies have shown that carbon dioxide supplementation (1000 micromoles mol-1) is of significant benefit under 12-h irradiance but less benefit under 24 h irradiance. Irradiance cycles of 60 minutes light and 30 minutes dark caused a reduction of more than 50% in tuber weight compared to cycles of 16 h light and 8 h dark. A diurnal temperature change of 22 degrees C for the 12-h light period to 14 degrees C during the 12-h dark period gave increased yields of 30% and 10% for two separate cultivars, compared with plants grown under a constant 18 degrees C temperature. Cultivar screening under continuous irradiance and elevated temperatures (28 degrees C) for 8 weeks of growth indicated that the cvs Haig, Denali, Atlantic, Desiree and Rutt had the best potential for tolerance to these conditions. Harvesting of tubers from plants at weekly intervals, beginning at 8 weeks after planting, did not increase yield over a single final harvest. Spacing of plants on 0.055 centers produced greater yield per m2 than spacing at 0.11 or 0.22 m2. Plants maintained 0.33 meters apart (0.111 m2 per plant) in beds produced the same yields when separated by dividers in the root matrix as when no separation was made. PMID:11537391

  13. Perspective: maternal kin groups and the origins of asymmetric genetic systems-genomic imprinting, haplodiploidy, and parthenogenesis.

    PubMed

    Normark, Benjamin B

    2006-04-01

    The genetic systems of animals and plants are typically eumendelian. That is, an equal complement of autosomes is inherited from each of two parents, and at each locus, each parent's allele is equally likely to be expressed and equally likely to be transmitted. Genetic systems that violate any of these eumendelian symmetries are termed asymmetric and include parent-specific gene expression (PSGE), haplodiploidy, thelytoky, and related systems. Asymmetric genetic systems typically arise in lineages with close associations between kin (gregarious siblings, brooding, or viviparity). To date, different explanatory frameworks have been proposed to account for each of the different asymmetric genetic systems. Haig's kinship theory of genomic imprinting argues that PSGE arises when kinship asymmetries between interacting kin create conflicts between maternally and paternally derived alleles. Greater maternal than paternal relatedness within groups selects for more "abstemious" expression of maternally derived alleles and more "greedy" expression of paternally derived alleles. Here, I argue that this process may also underlie origins of haplodiploidy and many origins of thelytoky. The tendency for paternal alleles to be more "greedy" in maternal kin groups means that maternal-paternal conflict is not a zero-sum game: the maternal optimum will more closely correspond to the optimum for family groups and demes and for associated entities such as symbionts. Often in these circumstances, partial or complete suppression of paternal gene expression will evolve (haplodiploidy, thelytoky), or other features of the life cycle will evolve to minimize the conflict (monogamy, inbreeding). Maternally transmitted cytoplasmic elements and maternally imprinted nuclear alleles have a shared interest in minimizing agonistic interactions between female siblings and may cooperate to exclude the paternal genome. Eusociality is the most dramatic expression of the conflict-reducing effects of

  14. Predictive Quantum Chemistry: A Step Toward ``Chemistry Without Test Tubes''

    NASA Astrophysics Data System (ADS)

    Perera, Ajith

    2007-12-01

    The merits of the claims made in two recent papers entitled "First generation of pentazole (HN5, pentazolic acid), the final azole, and a zinc pentazolate salt in solution: A new N-dearylation of 1-(p-methoxyphenyl) pyrazoles, a 2-(p-methoxyphenyl) tetrazole and application of the methodology to 1-(p-methoxyphenyl) pentazole" (R. N. Butler, J. C. Stephan and L. A. Burke, J. Chem. Commun. 2003, 1016-1017) and "First generation of the pentazolate anion is solution is far from over" (T. Schroer, R. Haiges, S. Schneider and K. O. Christe, Chem. Commun. 2005, 1607-1609) are verified by predictive quality theoretical methods. Knowing whether the CF3OH in HF solution undergoes protonation to form CF3[OH2]+ is critical to the success of the recently proposed synthetic route to form the prototype perfluorinated alcohol, CF3OH. Chirstie and co-workers first considered the 13C and 19F shielding constants to distinguish CF3OH and CF3[OH2]+, but it turns out that they both have similar chemical shifts. Furthermore, they noted that the computed 13C chemical shifts differ by 11 ppm from the measured ones and claimed that "These findings presented a dilemma because either experimental or the calculated shifts has to be seriously flawed and, therefore chemical shifts alone it was impossible to decide whether CF3OH in liquid HF is protonated or not". Instead of chemical shifts, they propose to use 13C-19F NMR spin-spin coupling constants and argue that the observed 20 Hz difference of 1J(13C-19F) to the increase in the covalent character upon protonation. The reported discrepancy in computed and measured chemical shifts is reexamined and the spin-spin coupling constants results are verified by the predicative-level calculations.

  15. New taxonomic and distributional information on hermit crabs (Crustacea: Anomura: Paguroidea) from the Gulf of Mexico, Caribbean Sea, and Atlantic coast of South America.

    PubMed

    Lemaitre, Rafael; Tavares, Marcos

    2015-01-01

    A collection of Paguroidea recently obtained during deep-water expeditions along the coast of Brazil, forms the basis of this report. Of the 14 species reported from Brazil, 11 represent range extensions to the south, and one, Michelopagurus atlanticus (Bouvier, 1922), is a first record for the western Atlantic. The specimens were compared with types and western Atlantic materials deposited in various major museums. A diagnosis and illustrations are presented for each of seven species found to be poorly or insufficiently known. New material and information is reported for two additional species that occur in Brazil but not found in the recent deep-water collections: Clibanarius symmetricus (Randall, 1840) and Mixtopagurus paradoxus A. Milne-Edwards, 1880. Remarkable and unique color photographs of live or fresh specimens of Allodardanus bredini Haig & Provenzano, 1965, Bathynarius anomalus (A. Milne-Edwards & Bouvier, 1893), Pylopagurus discoidalis (A. Milne-Edwards, 1880), Paguristes spinipes A. Milne-Edwards, 1880, Parapagurus pilosimanus Smith, 1876, and P. alaminos Lemaitre, 1986, are presented. A review of published records and museum collections of the terrestrial Coenobita clypeatus (Fabricius, 1787), has shown that the southern range limit of this species does not extend beyond the southern Caribbean and Trinidad and Tobago, and thus does not occur on the Brazilian coast as previously believed. A distribution map of C. clypeatus is provided based on specimens in the collections of the National Museum of Natural History, Smithsonian Institution. New distribution records in the Gulf of Mexico and southern Caribbean, and morphological information, are included for Pagurus rotundimanus Wass, 1963, a species originally described from the Florida Keys but rarely reported since. Relevant remarks on the taxonomy, morphology, and distribution of all these species are included. The revised list of Paguroidea known from Brazil is updated, and now includes a total of

  16. Estimating Longwave Atmospheric Emissivity in the Canadian Rocky Mountains

    NASA Astrophysics Data System (ADS)

    Ebrahimi, S.; Marshall, S. J.

    2014-12-01

    Incoming longwave radiation is an important source of energy contributing to snow and glacier melt. However, estimating the incoming longwave radiation from the atmosphere is challenging due to the highly varying conditions of the atmosphere, especially cloudiness. We analyze the performance of some existing models included a physically-based clear-sky model by Brutsaert (1987) and two different empirical models for all-sky conditions (Lhomme and others, 2007; Herrero and Polo, 2012) at Haig Glacier in the Canadian Rocky Mountains. Models are based on relations between readily observed near-surface meteorological data, including temperature, vapor pressure, relative humidity, and estimates of shortwave radiation transmissivity (i.e., clear-sky or cloud-cover indices). This class of models generally requires solar radiation data in order to obtain a proxy for cloud conditions. This is not always available for distributed models of glacier melt, and can have high spatial variations in regions of complex topography, which likely do not reflect the more homogeneous atmospheric longwave emissions. We therefore test longwave radiation parameterizations as a function of near-surface humidity and temperature variables, based on automatic weather station data (half-hourly and mean daily values) from 2004 to 2012. Results from comparative analysis of different incoming longwave radiation parameterizations showed that the locally-calibrated model based on relative humidity and vapour pressure performs better than other published models. Performance is degraded but still better than standard cloud-index based models when we transfer the model to another site, roughly 900 km away, Kwadacha Glacier in the northern Canadian Rockies.

  17. Mineralogy of Meteorite Groups

    NASA Technical Reports Server (NTRS)

    Rubin, Alan E.

    1997-01-01

    phases were formed by shock metamorphism. Martensite (a2-fe,Ni) has a distorted body-centered-cubic structure and formed by a shear transformation from taenite during shock reheating and rapid cooling. The C polymorphs diamond, lonsdaleite and chaoite formed by shock from graphite. Suessite formed in the North Haig ureilite by reduction of Fe and Si (possibly from olivine) via reaction with carbonaceous matrix material. Ringwoodite, the spinel form of (Mg,Fe)2Si04, and majorite, a polymorph of (Mg,Fe)Si03 with the garnet structure, formed inside shock veins in highly shocked ordinary chondrites. Secondary minerals in meteorite finds that formed during terrestrial weathering include oxides and hy-. droxides formed directly from metallic Fe-Ni by oxidation, phosphates formed by the alteration of schreibersite, and sulfates formed by alteration of troilite.

  18. Utilization of white potatoes in CELSS

    NASA Astrophysics Data System (ADS)

    Tibbitts, Theodore W.; Bennett, Susan M.; Morrow, Robert C.; Bula, Raymond J.

    Potatoes (Solanum tuberosum) have a strong potential as a useful crop species in a functioning CELSS. The cultivar Denali has produced 37.5 g m-2 d-1 when grown for 132 days with the first 40 days under a 12-h photoperiod and a light:dark temperature cycle of 20°C: 16°C, and then 92 days under continuous irradiance and a temperature of 16°C. Irradiance was at 725 μmol m-2 s-1 PPF and carbon dioxide at 1000 μmol mol-1. The dried tubers had 82% carbohydrates, 9% protein and 0.6% fat. Other studies have shown that carbon dioxide supplementation (1000 μmol mol-1) is of significant benefit under 12-h irradiance but less benefit under 24 h irradiance. Irradiance cycles of 60 minutes light and 30 minutes dark caused a reduction of more than 50% in tuber weight compared to cycles of 16 h light and 8 h dark. A diurnal temperature change of 22°C for the 12-h light period to 14°C during the 12-h dark period gave increased yields of 30% and 10% for two separate cultivars, compared with plants grown under a constant 18°C temperature. Cultivar screening under continuous irradiance and elevated temperatures (28°C) for 8 weeks of grown indicated that the cvs Haig, Denali, Atlantic, Desiree and Rutt had the best potential for tolerance to these conditions. Harvesting of tubers from plants at weekly intervals, beginning at 8 weeks after planting, did not increase yield over a single final harvest. Spacing of plants on 0.055 centers produced greater yield per m2 than spacing at 0.11 or 0.22 m2. Plants maintained 0.33 meters apart (0.111 m2 per plant) in beds produced the same yields when separated by dividers in the root matrix as when no separation was made.

  19. Foundations of Forensic Meteoritics

    NASA Astrophysics Data System (ADS)

    Treiman, A. H.

    1992-07-01

    It may be useful to know if a meteorite was found at the site where it fell. For instance, the polymict ureilites North Haig and Nilpena were found 1100 km apart, yet are petrologically identical [1]. Could this distance represent transport from a single strewn field, or does it represent distinct fall sites? A meteorite may contain sufficient clues to suggest some characteristics of its fall site. If these inferences are inconsistent with the find site, one may infer that the meteorite has been transported. It will likely be impossible to determine the exact fall site of a transported meteorite. Data relevant to a meteorite's fall site may be intrinsic to the meteorite, or acquired at the site. For instance, an intrinsic property is terrestrial residence age (from abundances of cosmogenic radioisotopes and their decay products); a meteorite's terrestrial residence age must be the same or less than that of the surface on which it fell. After falling, a meteorite may acquire characteristic telltales of terrestrial geological, geochemical, and biological processes. These telltale clues may include products of chemical weathering, adhering geological materials, biological organisms living (or once living) on the meteorite, and biological materials adhering to (but never living on) the meteorite. The effects of chemical weathering, present in all but the freshest finds, range from slight rusting to extensive decomposition and veining The ages of weathering materials and veins, as with terrestrial residence ages above, must be less than the age of the fall surface. The mineralogy and chemistry, elemental and isotopic, of weathering materials will differ according to the mineralogy and composition of the meteorite, and the mineralogy, geochemistry, hydrology, and climate of the fall site. Weathering materials may also vary as climate changes and may vary among the microenvironments associated with a meteorite on the Earth's surface. Geological materials (rock, sediment

  20. TASK 2.5.7 FIELD EXPERIMENTS TO EVALUATE COOL-COLORED ROOFING

    SciTech Connect

    Miller, William A; Cherry, Nigel J; Allen, Richard Lowell; Childs, Phillip W; Atchley, Jerald Allen; Ronnen, Levinson; Akbari, Hashem; Berhahl, Paul

    2010-03-01

    Aesthetically pleasing dark roofs can be formulated to reflect like a highly reflective white roof in the near infrared portion of the solar spectrum. New paint pigments increase the near infrared reflectance of exterior finishes by minimizing the absorption of near-infrared radiation (NIR). The boost in the NIR reflectance drops the surface temperatures of roofs and walls, which in turn reduces cooling-energy use and provides savings for the homeowner and relief for the utilities. In moderate and hot climates, a roof surface with high solar reflectance and high thermal emittance was shown by Akbari et al. (2004) and by Parker and Sherwin (1998) to reduce the exterior temperature and produce savings in comfort cooling. The new cool color pigments can potentially reduce emissions of carbon dioxide, which in turn reduces metropolitan heat buildup and urban smog. The pigments can also help conserve water resources otherwise used to clean and process fuel consumed by fossil-fuel driven power plants. Cool roofs also result in a lower ambient temperature that further decreases the need for air conditioning, retards smog formation, and improves thermal comfort. Parker, Sonne and Sherwin (2002) demonstrated that white barrel and white flat tiles reduced cooling energy consumption by 22% of the base load used by an adjacent and identical home having direct nailed dark shingles. Part of the savings was due to the reflectance of the white tiles; however, another part was due to the mass of the tile and to the venting occurring within the double batten installation. With, Cherry and Haig (2009) have studied the influence of the thermal mass and batten space ventilation and have found that, referenced to an asphalt shingle system, it can be equivalent to an additional 28 points of solar reflectivity. The double batten arrangement has wooden counter battens laid vertically (soffit-to-ridge) against the roof deck, and then the conventional battens are laid horizontally across the