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1

Aerosol influenza transmission risk contours: A study of humid tropics versus winter temperate zone  

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Full Text Available Abstract Background In recent years, much attention has been given to the spread of influenza around the world. With the continuing human outbreak of H5N1 beginning in 2003 and the H1N1 pandemic in 2009, focus on influenza and other respiratory viruses has been increased. It has been accepted for decades that international travel via jet aircraft is a major vector for global spread of influenza, and epidemiological differences between tropical and temperate regions observed. Thus we wanted to study how indoor environmental conditions (enclosed locations in the tropics and winter temperate zones contribute to the aerosol spread of influenza by travelers. To this end, a survey consisting of 632 readings of temperature (T versus relative humidity (RH in 389 different enclosed locations air travelers are likely to visit in 8 tropical nations were compared to 102 such readings in 2 Australian cities, including ground transport, hotels, shops, offices and other publicly accessible locations, along with 586 time course readings from aircraft. Results An influenza transmission risk contour map was developed for T versus RH. Empirical equations were created for estimating: 1. risk relative to temperature and RH, and 2. time parameterized influenza transmission risk. Using the transmission risk contours and equations, transmission risk for each country's locations was compared with influenza reports from the countries. Higher risk enclosed locations in the tropics included new automobile transport, luxury buses, luxury hotels, and bank branches. Most temperate locations were high risk. Conclusion Environmental control is recommended for public health mitigation focused on higher risk enclosed locations. Public health can make use of the methods developed to track potential vulnerability to aerosol influenza. The methods presented can also be used in influenza modeling. Accounting for differential aerosol transmission using T and RH can potentially explain anomalies of influenza epidemiology in addition to seasonality in temperate climates.

Borup Birthe

2010-05-01

2

Long range transport of caesium isotopes from temperate latitudes to the equatorial zone during the winter monsoon period  

International Nuclear Information System (INIS)

An air radioactivity monitoring study carried out at Dalat, Viet Nam, since 1986 has revealed distinct peaks of caesium isotope concentrations in air and fallout during the period of December and January when the monthly average air temperature was lowest and dry fallout dominated. These peaks provide evidence of the intrusion of more radioactive cold air masses from temperate northern latitudes during the development of large scale anticyclones, frequently observed in the most active winter monsoon period. The high dry fallout velocity (about 10 cm/s), determined from the measured concentrations, clearly demonstrates one of the most relevant features of cold air masses: behind the cold front, vertical air motion is descending. The role of other processes such as injection of radioactive air from the stratosphere and local resuspension of soil dust has been shown to be insignificant. The interpretation of the experimental results was based on the analysis of environmental-meteorological factors as well as the behaviour of other naturally occurring radionuclides. (author). 7 refs, 2 figs

1993-04-19

3

Winter disturbances and riverine fish in temperate and cold regions  

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Winter is a critical period for aquatic organisms; however, little is known about the ecological significance of its extreme events. Here, we link winter ecology and disturbance research by synthesizing the impacts of extreme winter conditions on riverine habitats and fish assemblages in temperate and cold regions. We characterize winter disturbances by their temporal pattern and abiotic effects, explore how various drivers influence fish, and discuss human alterations of winter disturbances ...

Weber, Christine; Nilsson, Christer; Lind, Lovisa; Alfredsen, Knut T.; Polvi, Lina E.

2013-01-01

4

Dams release methane even in temperate zoned  

International Nuclear Information System (INIS)

The Wohlen lake (near Bern) is a retaining dam built 90 years ago that has undergone a campaign to measure the quantity of methane released. The campaign lasted 1 year and the result was unexpected: 0.15 g/m2*day which one of the highest release rates in temperate zones. This result is all the more stunning since water stays only 2 days in average in the reservoir and that the drowned area is not important. In fact the river Aar that feeds the lake is loaded with organic matter coming from humane activities: agriculture and 3 sewage plants. This organic matter decays in the lake releasing methane. (A.C.)

2010-12-01

5

Establishing the Breeding Provenance of a Temperate-Wintering North American Passerine, the Golden-Crowned Sparrow, Using Light-Level Geolocation  

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The migratory biology and connectivity of passerines remains poorly known, even for those that move primarily within the temperate zone. We used light-level geolocators to describe the migratory geography of a North American temperate migrant passerine. From February to March of 2010, we attached geolocator tags to 33 Golden-crowned Sparrows (Zonotrichia atricapilla) wintering on the central coast of California, USA, and recovered four tags the following winter (October to December 2010). We ...

Seavy, Nathaniel E.; Humple, Diana L.; Cormier, Rene?e L.; Gardali, Thomas

2012-01-01

6

Recurrent winter warming pulses enhance nitrogen cycling and soil biotic activity in temperate heathland and grassland mesocosms  

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Winter air temperatures are projected to increase in the temperate zone, whereas snow cover is projected to decrease, leading to more extreme soil temperature variability, and potentially to changes in nutrient cycling. Therefore, we applied six winter warming pulses by infra-red heating lamps and surface heating wires in a field experiment over one winter in temperate heathland and grassland mesocosms. The experiment was replicated at two sites, a colder mountainous upland site with high snow accumulation and a warmer and dryer lowland site. Winter warming pulses enhanced soil biotic activity for both sites during winter, as indicated by 35% higher nitrogen (N) availability in the soil solution, 40% higher belowground decomposition and a 25% increase in the activity of the enzyme cellobiohydrolase. The mobilization of N differed between sites, and the incorporation of 15N into leaves was reduced by 31% in response to winter warming pulses, but only at the cold site, with significant reductions occurring for three of four tested plant species at this site. Furthermore, there was a trend of increased N leaching in response to the recurrent winter warming pulses. Overall, projected winter climate change in the temperate zone, with less snow and more variable soil temperatures, appears important for shifts in ecosystem functioning (i.e. nutrient cycling). While the effects of warming pulses on plant N mobilization did not differ among sites, reduced plant 15N incorporation at the colder temperate site suggests that frost damage may reduce plant performance in a warmer world, with important implications for nitrogen cycling and nitrogen losses from ecosystems.

Schuerings, J.; Jentsch, A.; Hammerl, V.; Lenz, K.; Henry, H. A. L.; Malyshev, A. V.; Kreyling, J.

2014-06-01

7

Thermal performance of natural airflow window in subtropical and temperate climate zones - A comparative study  

International Nuclear Information System (INIS)

Airflow window is highly useful in conserving building energy, and lessens the comfort problems caused by glazing. In this study, the thermal performance of a natural airflow window was examined through the use of a dynamic model, developed based on the integrated energy balance and airflow networks. The validity of the model was first tested by measured data obtained from a prototype installed at an environmental chamber. The application in the subtropical and temperate climate zones were then examined with the typical weather data of Hong Kong and Beijing. The findings confirmed that the natural airflow window can achieve substantial energy saving in both cities, and the reversible window frame is only required for Beijing, a location with hot summer and cold winter. The space cooling load via fenestration in Hong Kong, a subtropical city, can be reduced to 60% of the commonly used single absorptive glazing. In Beijing, as an example of the temperate climate, this can be reduced to 75% of the commonly used double glazing configuration in the summer period, and the space heat gain can be improved by 46% in the winter period.

2009-08-01

8

Winter stream temperature in the rain-on-snow zone  

Science.gov (United States)

Stream temperature is a principal determinant of aquatic ecosystem composition and productivity. There are increasing concerns that changes in land cover and climatic conditions could produce changes in stream thermal regimes that would be deleterious to existing aquatic communities. Most stream temperature research has focused on summer periods and few studies have examined winter periods despite the growing recognition of its biological importance. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones. This study examined winter stream temperature patterns and controls in small headwater catchments within the rain-on-snow zone at the Malcolm Knapp Research Forest, near Vancouver, British Columbia, Canada. Two working hypotheses were addressed by this study: (1) winter stream temperatures are primarily controlled by advective fluxes associated with runoff processes and (2) stream temperatures should be depressed during rain-on-snow events, compared to rain on bare ground, due to the cooling effect of rain passing through the snowpack prior to infiltrating the soil or being delivered to the stream as saturation-excess overland flow. These hypotheses were tested statistically using historical stream temperature data and modelled snowpack dynamics for a forested headwater catchment. When snow was not present, daily stream temperature during winter rain events tended to increase with increasing air temperature. However, when snow was present, stream temperature was capped at about 5 °C, regardless of air temperature. This historical analysis was complemented with detailed field data collected during the winter of 2011-2012 from an ongoing field study in a partially logged catchment. Stream temperature response to a large rain-on-snow event was compared to a rain-only event of similar magnitude. During the rain-on-snow event, stream temperature exhibited less variation and was similar to soil temperature measured at a near-stream site known to produce substantial subsurface stormflow. Both the historical and field studies support our hypotheses. A key implication is that climate warming may generate higher winter stream temperatures in the rain-on-snow zone due to both increased rain temperature and reduced cooling effect of snow cover.

Leach, J. A.; Moore, R. D.

2012-12-01

9

Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies  

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Full Text Available The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been limited to South America and New Zealand, are not fully consistent with each other and may be complicated by influences from other climatic factors. Here we present the first high-resolution diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation in the equatorward margin of the westerly wind belt during the last 1400 yr. Inferred rainfall was relatively high ?1400–1200 cal yr BP, decreased until ?950 cal yr BP, and rose notably through the Little Ice Age with pulses centred on ?600, 530, 470, 330, 200, 90, and 20 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations were linked to changes in the westerlies. Equatorward drift of the westerlies during the wet periods may have influenced Atlantic meridional overturning circulation by restricting marine flow around the tip of Africa. Apparent inconsistencies among some aspects of records from South America, New Zealand and South Africa warn against the simplistic application of single records to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in the austral winter rainfall zones with future warming.

J. C. Stager

2012-05-01

10

Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies  

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Full Text Available The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward contraction of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been largely limited to South America, are not fully consistent with each other, and may be complicated by influences from other climatic factors. Here we present the first fine-interval diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation during the last 1400 yr. Inferred rainfall increased ~1400–1200 cal yr BP and most notably during the Little Ice Age with pulses centered on ~600, 530, 470, 330, 200, and 90 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations are linked to changes in the westerlies. Partial inconsistencies among South African and South American records warn against the simplistic application of local-scale histories to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in austral winter rainfall zones with future warming.

J. C. Stager

2011-12-01

11

Precipitation variability in the winter rainfall zone of South Africa during the last 1400 yr linked to the austral westerlies  

Science.gov (United States)

The austral westerlies strongly influence precipitation and ocean circulation in the southern temperate zone, with important consequences for cultures and ecosystems. Global climate models anticipate poleward retreat of the austral westerlies with future warming, but the available paleoclimate records that might test these models have been limited to South America and New Zealand, are not fully consistent with each other and may be complicated by influences from other climatic factors. Here we present the first high-resolution diatom and sedimentological records from the winter rainfall region of South Africa, representing precipitation in the equatorward margin of the westerly wind belt during the last 1400 yr. Inferred rainfall was relatively high ?1400-1200 cal yr BP, decreased until ?950 cal yr BP, and rose notably through the Little Ice Age with pulses centred on ?600, 530, 470, 330, 200, 90, and 20 cal yr BP. Synchronous fluctuations in Antarctic ice core chemistry strongly suggest that these variations were linked to changes in the westerlies. Equatorward drift of the westerlies during the wet periods may have influenced Atlantic meridional overturning circulation by restricting marine flow around the tip of Africa. Apparent inconsistencies among some aspects of records from South America, New Zealand and South Africa warn against the simplistic application of single records to the Southern Hemisphere as a whole. Nonetheless, these findings in general do support model projections of increasing aridity in the austral winter rainfall zones with future warming.

Stager, J. C.; Mayewski, P. A.; White, J.; Chase, B. M.; Neumann, F. H.; Meadows, M. E.; King, C. D.; Dixon, D. A.

2012-05-01

12

Forests tend to cool the land surface in the temperate zone: An analysis of the mechanisms controlling radiometric surface temperature change in managed temperate ecosystems  

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Vegetation is an important control on the surface energy balance and thereby surface temperature. Boreal forests and arctic shrubs are thought to warm the land surface by absorbing more radiation than the vegetation they replace. The surface temperatures of tropical forests tend to be cooler than deforested landscapes due to enhanced evapotranspiration. The effects of reforestation on surface temperature change in the temperate zone is less-certain, but recent modeling efforts suggest forests have a global warming effect. We quantified the mechanisms driving radiometric surface changes following landcover changes using paired ecosystem case studies from the Ameriflux database with energy balance models of varying complexity. Results confirm previous findings that deciduous and coniferous forests in the southeastern U.S. are ca. 1 °C cooler than an adjacent field on an annual basis because aerodynamic/ecophysiological cooling of 2-3 °C outweighs an albedo-related warming of case studies are documented to have higher carbon uptake than the non-forested systems. Results suggest that temperate forests tend to cool the land surface and suggest that previous model-based findings that forests warm the Earth’s surface globally should be reconsidered.Changes to radiometric surface temperature (K) following changes in vegetation using paired ecosystem case studies C4 grassland and shrub ecosystem surface temperatures were adjusted for differences in air temperature across sites.

Stoy, P. C.; Katul, G. G.; Juang, J.; Siqueira, M. B.; Novick, K. A.; Essery, R.; Dore, S.; Kolb, T. E.; Montes-Helu, M. C.; Scott, R. L.

2010-12-01

13

Winter Temperature Response to Large Tropical Volcanic Eruptions in Temperate Western North America: Relationship to ENSO Phases  

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In light of anthropogenic climate forcing, significant evaluation of the climate system's response to a range of forcing factors has been undertaken. Responses to large tropical volcanic eruptions are a key focus area. Paleoclimatology offers a unique vehicle to extend the study of these responses over much longer periods than those available from instrumental data. In this work, we present a set of annually-resolved, late-winter temperature responses in temperate western North America over 1500-1980 CE, and evaluate, from a regional perspective, evidence that large tropical eruptions show a tendency towards an initial El Niño (EN) response followed by a delayed La Niña (LN) (c.f. Li et al., 2013, DOI:10.1038/NCLIMATE1936). The proxy information are primarily tree ring widths and some ring density data from the target reconstruction region (30-55° N, 95-130° W) and northern Mexico, which are calibrated and validated against 5x5° gridded instrumental temperature data. Calibration uses an optimized form of principal components spatial regression, and well-validated reconstructions (for both the regional average and spatially) were able to be achieved for the February-March (FM) period. The reconstructions are additionally validated by their capacity to resolve known regional composite EN and LN late-winter temperature patterns. Superposed epoch analysis (SEA, n=13) was used to determine the composite responses for a sequence of post-volcanic-event years. Results do not show an initial EN-like regional response, but do show LN-like patterns in post-event Years 3-5. The correlations of the SEA patterns for Years 3-4 with the LN regional composite are significant based on correlations observed in ensembles of random-event-year SEAs, which account for the strong regional ENSO teleconnection. Relative homogeneity of the SEA response for each post-event year is evaluated as the amplitude (signal) of the SEA composite relative to its variance (noise) across events. Relative to the same metric observed from the random-event-year SEAs, these S/N ratios are significant in the portions of the domain with the strongest anomalies in Years 1-4, especially Year 3, and then tend towards uniformly low/insignificant values indicating lessening entrainment across individual events as time progresses. Post-event 500mb FM geopotential height composites from the 20th Century Reanalysis (1871-2011 CE, n=5) are generally consistent with the SEA temperature patterns. In particular, the Year 1 pressure composite does not cohere with ENSO-related pressure composites, consistent with the very weak/weak pattern correlations this year shows with the EN/LN temperature composites; and the pressure composite in North America and the adjacent Pacific and Atlantic regions in Year 3 is strongly LN-like, consistent with the relatively strong pattern correlation this year shows with the LN temperature composite and the S/N results. The weakening entrainment across eruptions as post-event time progresses from Year 3 in the S/N results is also consistent with more variable pressure composites noted after that time. The LN-like response in Years 3-5 exhibits a slight shift of its southern warm anomaly to the north and west relative to composite LN conditions, which is isolated as a specifically post-eruption feature.

Wahl, E. R.; Diaz, H. F.; Smerdon, J. E.

2013-12-01

14

Challenges in the nutrition and management of herbivores in the temperate zone.  

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The expected higher global demand for animal proteins and the competition for starch and sugars between food, fuel and feed seem to favour herbivores that convert solar energy captured in fibrous plants into animal products. However, the required higher production level of herbivores questions the sustainability of this conversion. An increase in herbivore production can be achieved by increasing the number of animals associated with the increasing demand of plant biomass or by improving the efficiency with which plant biomass is converted into meat and milk. The potential to increase food production by cattle, the main food-producing herbivore in the temperate zones outside China, was considered in three production systems: grassland-based, mixed rain-fed and mixed irrigated systems. The potential to increase plant biomass production in grassland-based systems seems limited, unless fertiliser is imported in large quantities and crop production is increased, sacrificing valuable, high-quality grasslands, which often conflicts with sustainable production methods. Also, in mixed systems with high inputs of fertiliser or water, improvements in plant biomass production seem marginal and the main challenges for these systems are in breeding high-quality plant biomass at lower levels of fertiliser and the use of new co-products from food processing and bio-based economies. Consequently, the main challenge in herbivore nutrition management is to improve the efficiency of plant biomass utilisation. Stocking rate management along with seasonal variation in the grazing capacity of grasslands and moderate use of fertiliser may increase meat production in grassland-based systems by 400%. Improving plant biomass utilisation in the more industrialised mixed rain-fed systems seems possible by better feed storage technologies and for dairy cattle by improving animal health and lifetime production level. Managing the transition period seems crucial to achieve more sustainable mixed rain-fed and mixed irrigated dairy production systems. Whether sustainable production methods will be implemented also depends on macro-economic conditions and awareness of regional and global environmental concerns. PMID:23031652

van Vuuren, A M; Chilibroste, P

2013-03-01

15

Larval fish dynamics in the Nxaxo-Ngqusi Estuary Complex in the warm temperate–subtropical transition zone of South Africa  

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Full Text Available The larval fish assemblage was investigated in the permanently open Nxaxo-Ngqusi Estuary Complex, situated in the subtropical–warm temperate biogeographic boundary zone of South Africa. Larval and early juvenile fishes were collected in summer and winter of 2007 and 2008 using a mixed method approach by boat-based plankton tows in mid-channel waters and seine net hauls along the margins. In total, 20 455 fishes were collected representing 21 families and 40 taxa, of which 13 900 fishes were from mid-channel sites (15 families and 21 taxa. Seine net hauls along the estuary margins produced 6550 fishes representing 18 families and 33 taxa. Gobiidae was the dominant fish family in the mid-channel waters followed by the Clupeidae whereas the opposite was found in marginal waters. Estuary-resident larvae were the dominant group in the estuary complex. The catches typically reflected a more warmtemperate community, although subtropical-associated species were present. Fish density in mid-channel waters was higher in the Ngqusi arm than that of the Nxaxo arm, whereas along the marginal waters, CPUE was higher in the latter. Fish densities in mid-channel waters and PUE along the margins were typically higher in summer.

T.H. Wooldridge

2011-10-01

16

Winter accumulation in the percolation zone of Greenland measured by airborne radar altimeter  

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We here determine the surface elevation and the winter snow accumulation rate along a profile in the percolation zone of the Greenland Ice Sheet from data collected with ESA's Airborne SAR/Interferometric Radar Altimeter System (ASIRAS) in spring 2004. The altimeter data show that in addition to a backscatter peak at the air-snow interface a dominant second peak occurs. This second peak appears due to the strong scattering properties of the last summer surface layer. A robust re-tracking algo...

Helm, V.; Rack, W.; Cullen, R.; Nienow, P.; Mair, D.; Parry, V.; Wingham, D. J.

2007-01-01

17

Influence of the sea surface temperature conditions in the Pacific subarctic frontal zone on the pink salmon's winter survival ability  

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Similar to other high-latitude ocean basins, the subarctic Pacific exhibits strong seasonal and inter-annual variations in the abiotic factors of the environment, which, in turn, strongly influence biological objects. One of the principal factors of this kind is the temperature regime. For our research, we chose pink salmon because more than 90% of its natural mortality occurs precisely during the wintering period. The lifetime of pink salmon is only one year, and the conditions of their populations reflect the thermal regime of the given year. The main wintering area of Asian pink salmon is the part of the subarctic frontal zone located south of the Aleutian Islands (43° 46°N). This region features sufficiently high wintertime concentrations of chlorophyll a and temperature conditions favorable for pink salmon wintering. The interannual temperature variability in the frontal zone is close to zero, and the width of the frontal zone may significantly change depending on the winter severity. In “milder” winters, the area of wintering extends, while, in “severe” winters, it is rather narrow, the forage base for fish decreases, they become more accessible for predators, and their survival rates sharply drop.

Tananaeva, Yu. N.

2008-06-01

18

The Impact of Winter and Spring Temperatures on Temperate Tree Budburst Dates: Results from an Experimental Climate Manipulation  

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Budburst phenology is a key driver of ecosystem structure and functioning, and it is sensitive to global change. Both cold winter temperatures (chilling) and spring warming (forcing) are important for budburst. Future climate warming is expected to have a contrasting effect on chilling and forcing, and subsequently to have a non-linear effect on budburst timing. To clarify the different effects of warming during chilling and forcing phases of budburst phenology in deciduous trees, (i) we cond...

Fu, Yongshuo H.; Campioli, Matteo; Deckmyn, Gaby; Janssens, Ivan A.

2012-01-01

19

Litter decomposition and soil respiration in response to increased rainfall variability, winter warming and altered cutting frequency in a temperate grassland  

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Climate change is likely to alter decomposition rates through direct effects on soil biotic activity and indirect effects on litter quality with possible impacts on the global carbon budget and nutrient cycling. Currently, there is an urgent need to study combined effects of various climatic drivers and of agricultural practise on decomposition. In an in-situ litter bag experiment, we studied effects of rainfall variability (including drought plus heavy rain pulses and regular irrigation) interacting with winter warming and increased winter precipitation and with changes in cutting frequency, on decomposition in a temperate grassland. Litter bags contained mixed and species-specific litter out of all different climate and land-use manipulations and were placed within the plots of litter origin. Moreover, we aimed to disentangle causes for altered decomposition by following two further approaches: To study effects of changed leaf chemicals due to the manipulations we placed litter out of the experiment that has been pre-exposed to the manipulations before on an untreated standard plot outside the experiment. To assess effects of changed soil faunal activity, we investigated decomposition of standard material under differing rainfall variability. We further compare the observed decomposition results with soil respiration data. Decomposition was reduced when litter bags were exposed to drought for six weeks within an 11 months period. Neither additional winter rain nor winter warming had an effect on decomposition, probably because winter warming reduced snow cover and increased variability of surface temperatures. Climate manipulations did not change litter quality. Further, decomposition on the untreated standard plot was not affected by the climate manipulations that the litter previously was exposed to. Thus, reduced decomposition under extreme rainfall variability and drought may be mainly caused by a decrease in soil biotic activity, as indicated by reduced decomposition of standard material during drought. More frequent cutting strongly stimulated decomposition, however, this stimulating effect was absent under extreme rainfall variability including drought. The stimulation of decomposition under more frequent cutting was attributed to changes in litter quality, namely a decrease in C/N ratio. Accordingly, litter from more frequently cut communities decomposed faster on the untreated control plot outside the experiment. Projected increases in drought frequency and increased rainfall variability under climate change may inhibit decomposition and alter nutrient and carbon cycling along with soil quality. Especially decomposition in frequently cut grassland appears vulnerable towards drought.

Kreyling, Juergen; Walter, Julia; Grant, Kerstin; Beierkuhnlein, Carl; Jentsch, Anke

2013-04-01

20

Recovery of coastal ecosystems after large tsunamis in various climatic zones - review of cases from tropical, temperate and polar zones (Invited)  

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Large tsunamis cause significant changes in coastal ecosystems. They include modifications in shoreline position, sediment erosion and deposition, new initial soil formation, salination of soils and waters, removal of vegetation, as well as direct impact on humans and infrastructure. The processes and rate of coastal zone recovery from large tsunamis has been little studied but during the last decade a noteworthy progress has been made. This study focus on comparison of recovery processes in various climatic zones, namely in monsoonal-tropical, temperate and polar zone. It is based on own observation and monitoring in areas affected by 2004 Indian Ocean Tsunami in Thailand, 2011 Tohoku-oki tsunami in Japan and 2000 Paatuut landslide-generated tsunami in Vaigat Strait (west Greenland), as well as on review of published studies from those areas. The particular focus is on physical and biological recoveries of beaches, recovery of coastal vegetation, new soil formation in eroded areas and those covered by tsunami deposits, marine salt removal from soils, surface- and groundwater, as well as landscape adjustment after the tsunamis. The beach zone - typically the most tsunami-eroded zone, has been recovered already within weeks to months and has been observed to be in the pre-tsunami equilibrium stage within one year in all the climate zones, except for sediment-starved environments. The existing data on beach ecosystems point also to relatively fast recovery of meio- and macrofauna (within weeks to several months). The recovery of coastal vegetation depends on the rate of salt removal from soils or on the rate of soil formation in case of its erosion or burial by tsunami deposits. The salt removal have been observed to depend mainly on precipitation and effective water drainage. In tropical climate with seasonal rainfall of more 3000 mm the salt removal was fast, however, in temperate climate with lower precipitation and flat topography the salinities still exceeded the recommended concentrations for freshwater plants after one year. The new soil formation and vegetation recovery depends mainly on the rate of biological production. In tropical climate the vegetation largely recovered already after the first rainy season and supported the new soil formation. In temperate climate this process was much slower, in particular in flat lying areas and on coastal dunes with poor sandy soils. In polar climate only limited vegetation recovery (mainly of Salix species) has been observed after 12 years and vegetation withered due to salt stress still marked the tsunami inundation limit and the new soil formation was very slow and focused on low lying, wet areas buried with thin tsunami deposits cover. The post-tsunami recovery processes may be grouped into climate-related (vegetation recovery, removal of salts from soils) and non climate-related (e.g. beach recovery) or modified by climatic and local factors (for instance, the rate of tsunami deposits reworking and thus new soil formation). The rate of recovery varies from days / weeks as in case of beach recovery to several decades as in case of new soil formation on tsunami deposits. The study was partly funded by Polish National Science Centre grant No. 2011/01/B/ST10/01553. The review results from studies in collaboration with number of researchers from Australia, Japan, Poland, Thailand, United Kingdom and United States to whom I express sincere thanks.

Szczucinski, W.

2013-12-01

 
 
 
 
21

Soil warming effect on net ecosystem exchange of carbon dioxide during the transition from winter carbon source to spring carbon sink in a temperate urban lawn.  

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The significant warming in urban environment caused by the combined effects of global warming and heat island has stimulated widely development of urban vegetations. However, it is less known of the climate feedback of urban lawn in warmed environment. Soil warming effect on net ecosystem exchange (NEE) of carbon dioxide during the transition period from winter to spring was investigated in a temperate urban lawn in Beijing, China. The NEE (negative for uptake) under soil warming treatment (temperature was about 5 degrees C higher than the ambient treatment as a control) was -0.71 micromol/(m2 x sec), the ecosytem was a CO2 sink under soil warming treatment, the lawn ecosystem under the control was a CO2 source (0.13 micromol/(m2 x sec)), indicating that the lawn ecosystem would provide a negative feedback to global warming. There was no significant effect of soil warming on nocturnal NEE (i.e., ecosystem respiration), although the soil temperature sensitivity (Q10) of ecosystem respiration under soil warming treatment was 3.86, much lower than that in the control (7.03). The CO2 uptake was significantly increased by soil warming treatment that was attributed to about 100% increase of alpha (apparent quantum yield) and Amax (maximum rate of photosynthesis). Our results indicated that the response of photosynthesis in urban lawn is much more sensitive to global warming than respiration in the transition period. PMID:23534206

Zhou, Xiaoping; Wang, Xiaoke; Tong, Lei; Zhang, Hongxing; Lu, Fei; Zheng, Feixiang; Hou, Peiqiang; Song, Wenzhi; Ouyang, Zhiyun

2012-01-01

22

Tidal and spatial variations of DI13C and aquatic chemistry in a temperate tidal basin during winter time  

Science.gov (United States)

Here, the pelagic carbonate system and the ?13C signature of dissolved inorganic carbonate (DIC) were investigated in a tidal basin of the southern North Sea, the Jade Bay, with respect to tidal cycles and a transect towards the North Sea in winter time (January and November, 2010). Physical parameters, major and trace elements, and nutrient concentrations were considered, too. Primary production and pelagic organic matter respiration were negligible during winter time. Both, the compositional variations on the transects as well as during the tidal cycles indicate the mixing of North Sea with fresh water. The combined spatial co-variations of different parameters indicate an introduction of fresh water that was enriched in DI12C, metabolites (e.g., ammonia), protons, and dissolved redox-sensitive elements (e.g., Mn2 +). During the January campaign, the discharge via the flood gates was limited due to ice cover of the hinterland drainage ditches, allowing for an observation of tidal variations without significant mixing contributions from surface water discharges. Considering a binary mixing model with North Sea and fresh water as end-members, the extrapolated fresh water end-member composition for this campaign is estimated to contain about 3.8 mmol/kg DIC (?13C ? - 10 ± 1‰ vs. VPDB), and enhanced concentrations of NH4+, Mn2 +, and protons compared to North Sea water. The fast temporal response of dissolved geochemical tracers on tidal variations in the Jade Bay indicates a continuous supply of a fresh water component. The measured composition of fresh waters entering the Jade Bay via flood gates (end of October, 2010) did not match the values estimated by the binary mixing model. Therefore, the overall fresh water component likely is a mixture between sources originating from flood gates and (in January) dominating submarine groundwater discharge entering the Jade Bay. This model is consistent with the results obtained during the November campaign, when a more important contribution from flood gates is expected and a more variable fresh water end-member is estimated. The co-variations of the concentrations and the stable carbon isotope composition of DIC are applied to evaluate possible superimposed sink-source-transformation processes in the coastal waters and a general co-variation scheme is suggested.

Winde, V.; Böttcher, M. E.; Escher, P.; Böning, P.; Beck, M.; Liebezeit, G.; Schneider, B.

2014-01-01

23

Biological soil crusts are the main contributor to winter soil respiration in a temperate desert ecosystem of China  

Science.gov (United States)

Aims Biological soil crusts (BSCs) are a key biotic component of desert ecosystems worldwide. However, most studies carried out to date on carbon (fluxes) in these ecosystems, such as soil respiration (RS), have neglected them. Also, winter RS is reported to be a significant component of annual carbon budget in other ecosystems, however, we have less knowledge about winter RS of BSCs in winter and its contribution to carbon cycle in desert regions. Therefore, the specific objectives of this study were to: (i) quantify the effects of different BSCs types (moss crust, algae crust, physical crust) on the winter RS; (ii) explore relationships of RS against soil temperature and water content for different BSCs, and (iii) assess the relative contribution of BSCs to the annual amount of C released by RS at desert ecosystem level. Methods Site Description The study sites are located at the southeast fringe of the Tengger Desert in the Shapotou region of the Ningxia Hui Autonomous Region [37°32'N and 105°02'E, at 1340 m above mean sea level (a.m.s.l.)], western China. The mean daily temperature in January is -6.9°C , while it is 24.3°C in July. The mean annual precipitation is 186 mm, approximately 80% of which falls between May and September. The annual potential evaporation is 2800 mm. The landscape of the Shapotou region is characterized by large and dense reticulate barchans chains of sand dunes that migrate south-eastward at a velocity of 3-6 m per year. The soil is loose, infertile and mobile and can thus be classified as orthic sierozem and Aeolian sandy soil. Additionally, the soil has a consistent gravimetric water content that ranges from 3 to 4%. The groundwater in the study area is too deep (>60 m) to support large areas of the native vegetation cover; therefore, precipitation is usually the only source of freshwater. The predominant native plants are Hedysarum scoparium Fisch. and Agriophyllum squarrosum Moq., Psammochloa cillosa Bor, which scattered distribute with cover about 1% of the entire study area. Prior to revegetation, straw-checkerboards approximately 1×1 m2 in area were constructed using wheat or rice straw to stabilize the dune surface and allow time for the planted xerophytic shrubs to adapt to the new environment. In 1956, the following 2-year-old xerophytic shrub seedlings were planted within the checkerboard at a density of 16 individuals per 100 m2 and grown without irrigation: Artemisia ordosica Krasch, H. scoparium Fisch, Calligonum mongolicum Turc'z, Caragana microphylla Lam., Caragana korshinskii Kom, Salix gordejevii and Atraphaxis bracteata A.Los. The stabilized area was then expanded to parallel areas in 1964 and 1982 using the same method and species. As a result, the initial stages of change that have occurred at these sites were similar. After more than fifties years succession, the predominant plants are semi-shrubs, shrubs, forbs, and grasses at present and BSCs formed. The common BSCs in the region may be dominated by cyanobacteria, algae, lichens and mosses, or any combination of these organisms. Cyanobacteria species include Microcolous vaginatus Gom., Hydrocoleus violacens Gom., Lyngbya crytoraginatus Schk., Phormidium amblgum Gom., P. autumnale (Ag.) Gom., P. foveolarum (Mont.) Gom. and Phormidium luridum (Kutz) Gom. etc; algal species mainly include Anabaena azotica Ley, Euglena sp., Hantzschia amphioxys var capitata Grum, Oscillatoria obscura Gom., O. pseudogeminate G. Schm. And Scytonema javanicum (Kutz) Bornet Flash etc; lichen species include Collema tenax (Sw.) Ach., Endocarpon pusillum Hedw.; and moss species are dominated by Bryum argenteum Hedw., Didymodon constrictus (Mitt.) Saito., Tortula bidentata Bai Xue Liang and T. desertorum Broth.. Experimental Design and Rs measurements On October 2010, We selected the moss-dominated BSCs at four revegetation sites and natural vegetation sites, in which 3 replicated plots were selected randomly. In each plot, olyvinyl chloride (PVC) collar (lenth 10 cm, internal diameter 10cm ) were inserted 7 cm into the soil. During the

He, M. Z.

2012-04-01

24

Winter stream temperature in the rain-on-snow zone of the Pacific northwest: influences of hillslope runoff and transient snow cover  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Stream temperature dynamics during winter are less well studied than summer thermal regimes, but the winter season thermal regime can be critical for fish growth and development in coastal catchments. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones....

Leach, J. A.; Moore, R. D.

2013-01-01

25

Towards a better understanding of the systematics and diversity of Cortinarius, with an emphasis on species growing in boreal and temperate zones of Europe and North America  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Towards a better understanding of the systematics and diversity of Cortinarius, with an emphasis on species growing in boreal and temperate zones of Europe and North America Cortinarius is the largest genus of Agaricales with a global distribution and thousands of species. Cortinarius species are important ectomycorrhizal fungi associated with different trees. At the moment, any estimation of the true diversity of Cortinarius is impossible to determine.

2013-01-01

26

Cultivation effects on biochemical properties, C storage and 15N natural abundance in the 0-5 cm layer of an acidic soil from temperate humid zone.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Changes in some soil chemical, including 15N values, and biochemical properties (microbial C, FDA hydrolysis, glucosidase and urease activities) due to two tillage systems, conventional tillage (CT) and no tillage (NT), were evaluated in an acid soil from temperate humid zone (NW of Spain) and compared with values obtained for a reference forest soil. The results showed that in the surface layer (0-5 cm depth) tillage tended to increase soil pH and to decrease organic matter level...

Di?az Ravin?a, M.; Bueno, J.; Gonza?lez Prieto, S. J.; Carballas, T.

2005-01-01

27

Holocene climate variability in the Winter Rainfall Zone of South Africa  

Science.gov (United States)

We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes and grain size of terrigenous fraction, and ?18O and ?13C in tests of Neogloboquadrina pachyderma (sinistral) from a marine sediment sequence recovered off the Orange River. The records reveal coherent patterns of variability that reflect changes in wind strength, precipitation over the river catchments, and upwelling of cold and nutrient-rich coastal waters off western South Africa. The wettest episode of the Holocene in the Winter Rainfall Zone (WRZ) of South Africa occurred during the "Little Ice Age" (700-100 yr BP). Wet phases were accompanied by strengthened coastal water upwellings, a decrease of Agulhas water leakage into the southern Atlantic, and a reduced dust incursion over Antarctica. A continuous aridification trend in the WRZ and a weakening of the southern Benguela Upwelling System (BUS) between 9000 and 5500 yr BP parallel with increase of dust deposition over Antarctica and an enhanced leakage of warm Agulhas water into the southeastern Atlantic. The temporal relationship between precipitation changes in the WRZ, the thermal state of the coastal surface water, and leakage of warm water in southern Atlantic, and variation of dust incursion over Antarctica suggests a causal link that most likely was related to latitudinal shifts of the Southern Hemisphere westerlies. Our results of the mid-Holocene time interval may serve as an analogue to a possible long-term consequence of the current and future southward shift of the westerlies that may result in a decline of rainfall over southwest Africa and a weakened upwelling with implication for phytoplankton productivity and fish stocks. Furthermore, warming of the coastal surface water as a result of warm Agulhas water incursion into the southern BUS may affect coastal fog formation that is critical as moisture source for the endemic flora of the Namaqualand.

Weldeab, S.; Stuut, J.-B. W.; Schneider, R. R.; Siebel, W.

2013-05-01

28

Community structure and trophic ecology of zooplankton in the scotia sea marginal ice zone in winter (1988)  

Science.gov (United States)

Zooplankton community structure and trophic ecology were investigated in the marginal ice zone of the Southern Scotia Sea during the austral winter of 1988 as part of the AMERIEZ program. In the study area, near the South Orkneys (34-49°W, 57-61.5°S), water emerging from the Weddell Sea mixed with Scotia Sea water to form a complex field of mesoscale eddies and meanders. Three primary zooplankton communities were identified: a shallow cold water assemblage typical of Weddell Sea water; a shallow/upper mesopelagic assemblage of subantarctic species introduced into the southern Scotia Sea with warm core eddies from the Polar Front; and a deep (>400 m) mesopelagic community with circumtantartic species. Zooplankton numerical dominants were cyclopoid copepods (mostly Oithona spp.); biomass dominants were four calanoid copepods, Calanoides acutus, Rhincalanus gigas, Calanus propinquus and Metridia gerlachei. Calanoides acutus and R. gigas were undergoing winter diapause in the mesopelagic zone (>400 m) whereas M. gerlachei and C. propinquus were distributed throughout the water column. In the subantarctic eddies M. gerlachei was replaced by M. lucens as a dominant and R. gigas was more abundant than in cold water to the south. Diet analysis of 35 dominant species revealed five feeding guilds among the zooplankton. One consisted primarily of small herbivorous copepods. Two closely related guilds consisting of copepods, krill and salps were omnivorous, feeding on phytoplankton, protozoans, metazoans and crustacean debris (molts). Two guilds were constituted by predatory copepods and chaetognaths. A sixth group, all copepods, which included important numerical and biomass dominants of the region, was trophically inactive. A comparison of gut fullness between winter 1988 and fall 1986 revealed that all but two of 19 small particle grazing species had significantly less food in their guts in winter. The exceptions were the biomass dominants C. propinquus and M. gerlachei, which were actively feeding in winter. Phytoplankton biomass was low in winter, averaging two-thirds that in fall. Several major trophic pathways from phytoplankton through apex predators (birds and mammals) are proposed for winter in the southern Scotia Sea with zooplankton playing a central role in each.

Hopkins, Thomas L.; Lancraft, Thomas M.; Torres, Joseph J.; Donnelly, Joseph

1993-01-01

29

Skin diseases in a Merino sheep herd related to an excessively rainy winter in a Mediterranean climatic zone.  

Science.gov (United States)

A retrospective study is presented here in which an outbreak of dermatophilosis and morbidity of fleece rot in a sheep herd grazing throughout the year in the Carmel hills are described for the first time in a Mediterranean climatic zone. Both diseases were closely related to intense and prolonged rains during the winter months of 1991/1992. Morbidity of dermatophilosis appeared after 650 mm and that of fleece rot after 1320 mm of precipitation. The pathogenesis of these diseases is discussed. PMID:8592878

Yeruham, I; Elad, D; Nyska, A

1995-03-01

30

Optimization of Water Management in Polder Areas; Some examples for the temperate humid and the humid tropical zone:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The demand of land for producing food, for urban development such as housing, industry, shopping areas, infrastructure and also for recreation has increased during the history of mankind. This has, among others, resulted in the reclamation of swamps, flood plains, tidal areas and even lakes by impoldering. To get insight in the system behavior for different land use and soil composition under temperate humid and humid tropic conditions, model simulations can be used. The existing package O...

Wandee, P.

2005-01-01

31

Winter stream temperature in the rain-on-snow zone of the Pacific northwest: influences of hillslope runoff and transient snow cover  

Directory of Open Access Journals (Sweden)

Full Text Available Stream temperature dynamics during winter are less well studied than summer thermal regimes, but the winter season thermal regime can be critical for fish growth and development in coastal catchments. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones. This study examined winter stream temperature patterns and controls in small headwater catchments within the rain-on-snow zone at the Malcolm Knapp Research Forest, near Vancouver, British Columbia, Canada. Two hypotheses were addressed by this study: (1 winter stream temperatures are primarily controlled by advective fluxes associated with runoff processes and (2 stream temperatures should be depressed during rain-on-snow events, compared to rain-on-bare-ground, due to the cooling effect of rain passing through the snowpack prior to infiltrating the soil or being delivered to the stream as saturation-excess overland flow. A reach-scale energy budget analysis of two winter seasons revealed that the advective energy input associated with hillslope runoff overwhelms the effects of energy exchanges at the stream surface during rain and rain-on-snow events. Historical stream temperature data and modelled snowpack dynamics were used to explore the influence of transient snow cover on stream temperature over 13 winters. When snow was not present, daily stream temperature during winter rain events tended to increase with increasing air temperature. However, when snow was present, stream temperature was capped at about 5 °C, regardless of air temperature. The stream energy budget modelling and historical analysis support both of our hypotheses. A key implication is that climatic warming may generate higher winter stream temperatures in the rain-on-snow zone due to both increased rain temperature and reduced cooling effect of snow cover.

J. A. Leach

2013-10-01

32

Uptake of and follow-up supply with [benzene ring-U-14C]triademinol via the caryopsis and from dressed zones after seed treatment of winter barley and winter wheat using a dry dressing formula  

International Nuclear Information System (INIS)

The paper on hand studies the following issues: 1) What is the course of uptake of the agent and/or its metabolites into the plant following dry seed treatment of winter barley and winter wheat with [benzene ring-U-14C] triadimenol and sowing in the top-soil of a loess-based grey-brown podzolic soil. 2) What is the relevance of uptake and follow-up supply from the dressed zones of plants in neighbouring rows. 3) What is the extent of uptake and follow-up supply via the roots from dressed zones of neighbouring plants within the same row. 4) What is the course of dressed-zone formation following dry treatment of winter barley and winter wheat and sowing in the top-soil of a loess-based grey-brown podzolic soil. 5) What is the quantitative distribution of the agent on the pericarp of winter wheat caryopses following dry seed treatment. 6) Will the 14C-labelled agent be taken up, too, via the caryopsis and be translocated in scion and root. 7) What are the pathways of the agent from the caryopsis into the embryo. 8) How long will follow-up supply via the scutellum continue. The results concerning issues 1 to 4 were taken from tests with field lysimeters. Experiments concerning issues 6-8 were performed without soil in an climatic chamber. (orig./MG)

1984-01-01

33

Effects of storm runoff on the thermal regime and water quality of a deep, stratified reservoir in a temperate monsoon zone, in Northwest China.  

Science.gov (United States)

Jinpen Reservoir is a deep, stratified reservoir in Shaanxi province, located in a warm temperate zone of Northwest China. Influenced by a temperate monsoon climate, more than 60% of the annual precipitation is concentrated from late summer to autumn (July-September). In recent years, extreme rainfall events occurred more frequently and strongly affected the thermal structure, mixing layer depth and evolution of stratification of Jinpen Reservoir. The reservoir's inflow volume increased sharply after heavy rainfall during the flooding season. Large volumes of inflow induced mixing of stratified water zones in early autumn and disturbed the stratification significantly. A temporary positive effect of such disturbance was the oxygenation of the water close to the bottom of the reservoir, leading to inhibition of the release of nutrients from sediments, especially phosphate. However, the massive inflow induced by storm runoff with increased oxygen-consuming substances led to an increase of the oxygen consumption rate. After the bottom water became anaerobic again, the bottom water quality would deteriorate due to the release of pollutants from sediments. Heavy rainfall events could lead to very high nutrient input into the reservoir due to massive erosion from the surrounding uninhabited steep mountains, and the particulate matter contributed to most nutrient inputs. Reasonably releasing density flow is an effective way to reduce the amounts of particulate associated pollutants entering the reservoir. Significant turbid density flow always followed high rainfall events in Jinpen Reservoir, which not only affected the reservoir water quality but also increased costs of the drinking water treatment plant. Understanding the effects of the storm runoff on the vertical distributions of water quality indicators could help water managers to select the proper position of the intake for the water plant in order to avoid high turbidity outflow. PMID:24485908

Huang, Tinglin; Li, Xuan; Rijnaarts, Huub; Grotenhuis, Tim; Ma, Weixing; Sun, Xin; Xu, Jinlan

2014-07-01

34

Evaluation on energy and thermal performance for residential envelopes in hot summer and cold winter zone of China  

International Nuclear Information System (INIS)

As a result of rapid economic growth in the last several decades, energy issue is becoming more and more important in today's world because of a possible energy shortage in the future; the usage of residential electricity has increased rapidly in China and building energy efficiency is included as one of the 10 key programs targeting energy efficiency improvement in the 11th Five-Year Plan. In response to the growing concerns about energy conservation in residential buildings and its implications for the environment, systematic evaluation on energy and thermal Performance for residential envelops (EETP) is put forward to assess the energy efficiency of envelop designs and to calculate the energy consumption of cooling and heating systems. Hot summer and cold winter zone of China was selected for EETP analysis because of its rigorous climatic and huge energy consumption. The correlations between EETPs and electricity consumptions in cooling season, heating season, and the whole year were built in Shanghai, Changsha, Shaoguan and Chengdu, which represent A, B, C and D subzone of hot summer and cold winter zone in China, respectively. Illustrations indicate that the algorithm is simple and effective, energy and thermal performance of residential envelopes can be evaluated easily. The maximum allowable values of EETPs were determined when just meeting the compulsory indices of Standard JGJ134-2001, the corresponding allowable EETPs were also gained when achieving different energy-saving degrees on basis of it. EETP method can suggest possible ways to improve the energy efficiency for envelope designs of new building and retrofits of existing buildings and provide governments some useful information for the establishment of new policy on energy efficiency buildings. It has important meanings to carry out sustainable residential building designs with high thermal comfort and low energy consumption.

2009-10-01

35

Temporal dynamics of soil organic carbon after land-use change in the temperate zone â?? carbon response functions as a model approach  

DEFF Research Database (Denmark)

Land-use change (LUC) is a major driving factor for the balance of soil organic carbon (SOC) stocks and the global carbon cycle. The temporal dynamic of SOC after LUC is especially important in temperate systems with a long reaction time. On the basis of 95 compiled studies covering 322 sites in the temperate zone, carbon response functions (CRFs) were derived to model the temporal dynamic of SOC after five different LUC types (mean soil depth of 30±6 cm). Grassland establishment caused a long lasting carbon sink with a relative stock change of 128±23% and afforestation on former cropland a sink of 116±54%, 100 years after LUC (mean±95% confidence interval). No new equilibrium was reached within 120 years. In contrast, there was no SOC sink following afforestation of grasslands and 75% of all observations showed SOC losses, even after 100 years. Only in the forest floor, there was carbon accumulation of 0.38±0.04 Mg ha-1 yr-1 in afforestations adding up to 38±4 Mg ha-1 labile carbon after 100 years. Carbon loss after deforestation (-32±20%) and grassland conversion to cropland (-36±5%), was rapid with a new SOC equilibrium being reached after 23 and 17 years, respectively. The change rate of SOC increased with temperature and precipitation but decreased with soil depth and clay content. Subsoil SOC changes followed the trend of the topsoil SOC changes but were smaller (25±5% of the total SOC changes) and with a high uncertainty due to a limited number of datasets. As a simple and robust model approach, the developed CRFs provide an easily applicable tool to estimate SOC stock changes after LUC to improve greenhouse gas reporting in the framework of UNFCCC.

Poeplau, Christopher; Don, Axel

2011-01-01

36

Microwave and physical properties of sea ice in the winter marginal ice zone  

Science.gov (United States)

Surface-based active and passive microwave measurements were made in conjunction with ice property measurements for several distinct ice types in the Fram Strait during March and April 1987. Synthesis aperture radar imagery downlinked from an aircraft was used to select study sites. The surface-based radar scattering cross section and emissivity spectra generally support previously inferred qualitative relationships between ice types, exhibiting expected separation between young, first-year and multiyear ice. Gradient ratios, calculated for both active and passive data, appear to allow clear separation of ice types when used jointly. Surface flooding of multiyear floes, resulting from excessive loading and perhaps wave action, causes both active and passive signatures to resemble those of first-year ice. This effect could possibly cause estimates of ice type percentages in the marginal ice zone to be in error when derived from aircraft- or satellite-born sensors.

Tucker, W. B., III; Perovich, D. K.; Gow, A. J.; Grenfell, T. C.; Onstott, R. G.

1991-01-01

37

Winter stream temperature in the rain-on-snow zone of the Pacific Northwest: influences of hillslope runoff and transient snow cover  

Directory of Open Access Journals (Sweden)

Full Text Available Stream temperature dynamics during winter are less well studied than summer thermal regimes, but the winter season thermal regime can be critical for fish growth and development in coastal catchments. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones. This study examined winter stream temperature patterns and controls in small headwater catchments within the rain-on-snow zone at the Malcolm Knapp Research Forest, near Vancouver, British Columbia, Canada. Two hypotheses were addressed by this study: (1 winter stream temperatures are primarily controlled by advective fluxes associated with runoff processes and (2 stream temperatures should be depressed during rain-on-snow events, compared to rain-on-bare-ground events, due to the cooling effect of rain passing through the snowpack prior to infiltrating the soil or being delivered to the stream as saturation-excess overland flow. A reach-scale energy budget analysis of two winter seasons revealed that the advective energy input associated with hillslope runoff overwhelms vertical energy exchanges (net radiation, sensible and latent heat fluxes, bed heat conduction, and stream friction and hyporheic energy fluxes during rain and rain-on-snow events. Historical stream temperature data and modelled snowpack dynamics were used to explore the influence of transient snow cover on stream temperature over 13 winters. When snow was not present, daily stream temperature during winter rain events tended to increase with increasing air temperature. However, when snow was present, stream temperature was capped at about 5 °C, regardless of air temperature. The stream energy budget modelling and historical analysis support both of our hypotheses. A key implication is that climatic warming may generate higher winter stream temperatures in the rain-on-snow zone due to both increased rain temperature and reduced cooling effect of snow cover.

J. A. Leach

2014-02-01

38

Winter stream temperature in the rain-on-snow zone of the Pacific Northwest: influences of hillslope runoff and transient snow cover  

Science.gov (United States)

Stream temperature dynamics during winter are less well studied than summer thermal regimes, but the winter season thermal regime can be critical for fish growth and development in coastal catchments. The winter thermal regimes of Pacific Northwest headwater streams, which provide vital winter habitat for salmonids and their food sources, may be particularly sensitive to changes in climate because they can remain ice-free throughout the year and are often located in rain-on-snow zones. This study examined winter stream temperature patterns and controls in small headwater catchments within the rain-on-snow zone at the Malcolm Knapp Research Forest, near Vancouver, British Columbia, Canada. Two hypotheses were addressed by this study: (1) winter stream temperatures are primarily controlled by advective fluxes associated with runoff processes and (2) stream temperatures should be depressed during rain-on-snow events, compared to rain-on-bare-ground events, due to the cooling effect of rain passing through the snowpack prior to infiltrating the soil or being delivered to the stream as saturation-excess overland flow. A reach-scale energy budget analysis of two winter seasons revealed that the advective energy input associated with hillslope runoff overwhelms vertical energy exchanges (net radiation, sensible and latent heat fluxes, bed heat conduction, and stream friction) and hyporheic energy fluxes during rain and rain-on-snow events. Historical stream temperature data and modelled snowpack dynamics were used to explore the influence of transient snow cover on stream temperature over 13 winters. When snow was not present, daily stream temperature during winter rain events tended to increase with increasing air temperature. However, when snow was present, stream temperature was capped at about 5 °C, regardless of air temperature. The stream energy budget modelling and historical analysis support both of our hypotheses. A key implication is that climatic warming may generate higher winter stream temperatures in the rain-on-snow zone due to both increased rain temperature and reduced cooling effect of snow cover.

Leach, J. A.; Moore, R. D.

2014-02-01

39

Weed infestation of crops in different soils in the protective zone of Roztocze National Park. Part I. Winter and spring cereals  

Directory of Open Access Journals (Sweden)

Full Text Available The study on weed infestation of crops in different soils in the protective zone of RPN was conducted in the years 1991-1995. The characterization of weed infestation of winter and spring cereals was based on 306 phytosociological records. made with the use of Braun-Blanquet method. The degree of weed infestation in the fields in the protective zone of RPN depended on environment conditions. Both winter and spring cereals in majority of soils were most infested by: Cenaturea cyanus, Apera spica-venti and Vicia hirsta. In the lightest podsolic soils, made of loose sand and slightly loamy sand. winter and spring cereals were additionally infested by Equisetum arvense and two acidophylic species: Seleranthus annuus and Spergula arvensis. The crops in brown loess soil were infested by Matricaria maritima subsp. inodora. The most difficult weed species in brown soil formed from gaizes and limestone soil were: Convolvulus arvensis, Papaver rhoeas and Galium aparine. Moreover winter cercals in limestone soil showed high or medium infestation with Consolida regalis, Aethusa cynapium, Lathyrus tuberosus and low infestation with Apera spica-venti and Centaurea cyanus. Spring cereals were less infested than winter cereals. Apera spica-venti and Centaurea cyanus were less common with spring cereals than with winter cereals. Also, spring cereals showed high or medium infestation with Convolvulus arvensis. Spring cereals in some soil units were infested by Chenopodium album and Stellaria media. There was also higher infestation of spring cereals in limestone soils with Avena fatua, Veronica persica, Sinapis arvensis and Sonchus arvensis, compared to winter cereals in limestone soils.

Marta Ziemi?ska-Smyk

2004-12-01

40

Variation in cold hardiness of nondiapausing eggs of nine Aedes (Stegomyia) species (Diptera: Culicidae) from eastern Asia and Pacific islands ranging from the tropics to the cool-temperate zone.  

Science.gov (United States)

Variation in cold hardiness was studied in the laboratory for the nondiapausing eggs of nine Aedes (Stegomyia) species from eastern Asia and Pacific islands, ranging from the tropics to the cool-temperate zone. Species included were Aedes aegypti (L.), Aedes albopictus (Skuse), Aedes flavopictus Yamada, Aedes galloisi Yamada, Aedes hensilli Farner, Aedes palauensis Bohart, Aedes paullusi Stone and Farner, Aedes riversi Bohart and Ingram, and Aedes scutellaris (Walker). For species with distributions covering two or three climatic zones, at least one population was included from each zone, except for Ae. aegypti (subtropical populations were unavailable). Some eggs of four species confined to the tropical zone survived short exposure to freezing temperature (> or = -5 degrees C) when humidity was high. There were inter- and intraspecies variations in cold hardiness of nondiapausing eggs. Cold hardiness in each climatic zone differed in that populations of species with more northerly distributions were more cold-hardy than species with southerly distributions. In Ae. albopictus and Ae. flavopictus that cover three climatic zones, populations from cooler regions were more cold-hardy than populations from warmer regions. A possibility of southern species without diapausing eggs to colonize temperate eastern Asia was discussed. PMID:21485356

Mogi, Motoyoshi

2011-03-01

 
 
 
 
41

Thermal cycle effect on the microstructure of heat affected zone of a tempered and quenched; Efeito do ciclo termico na microestrutura da zona afetada pelo calor (ZAC) de um aco ABRL temperado e revenido  

Energy Technology Data Exchange (ETDEWEB)

The phase transformations in the heat affected zone of a quenched and tempered high strength low alloy steel was investigated. The following regions was investigated: coarse grained region, inter-critically re-heated coarse grained region and inter-critically re-heated region. Simulations of thermal cycles using salt baths was employed to reproduce the microstructure of the desired regions and to relate them to welding parameters such as peak temperature and velocity of cooling. 10 figs., 3 tabs., 16 refs.

Seabra, Ana L.F. [Associacao Brasileira de Metais (ABM), Sao Paulo, SP (Brazil); Assuncao, Fernando C.R. [Pontificia Univ. Catolica do Rio de Janeiro, RJ (Brazil). Dept. de Ciencia dos Materiais e Metalurgia

1990-12-31

42

Patterns of tree seedling mortality in a temperate-mediterranean transition zone forest in Chile Patrones en la mortalidad de plántulas de especies arbóreas de un bosque de la transición templado-mediterránea de Chile  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Seedling mortality in forests is the net result of an array of processes that vary spatially and temporally. We quantified emergence and mortality of seedlings at monthly intervals for two years, in a forest situated in the transition zone between the Mediterranean and temperate regions of Chile. We aimed to determine if survival of species responded differentially to seasonal water availability, to the spatial variation in light availability and to seedling density. The commonest species in ...

TERESA PARADA; Lusk, Christopher H.

2011-01-01

43

Determinação por cromatografia gasosa de açúcares em frutíferas de clima temperado / Gas chromatography determination of sugars in temperate-zone fruit trees  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese As frutíferas de clima temperado apresentam o fenômeno da dormência. Na saída da dormência, há a conversão do amido para açúcares solúveis, como substrato para a retomada de crescimento na primavera. Visando à maior compreensão da fisiologia das plantas em respostas a eventos, como as variações clim [...] áticas, estresses e problemas de adaptação, desenvolveu-se este trabalho, no Laboratório de Fisiologia Vegetal da Embrapa Clima Temperado, com o objetivo de descrever uma metodologia para a determinação das concentrações dos açúcares solúveis (frutose, sorbitol, alfa-glicose, beta-glicose e sacarose), em tecidos vegetais de frutíferas, via cromatografia gasosa. O cromatógrafo utilizado para as análises dos açúcares por essa metodologia é o GAS CHROMATOGRAPH e a coluna do tipo Packed Column J. K. de 3,2mm de diâmetro por 2m de comprimento, empacotada com Silicone SE-52 Uniport HP 80/100 mesh. Através da cromatografia gasosa, obtêm-se eficiência e resolução cromatográfica, para análises de açúcares solúveis, sendo, desta forma, vantajoso e executável esse tipo de análise pelo método descrito. Abstract in english The temperate-zone deciduous fruit trees present the phenomenon of dormancy. In that period, there is the conversion of the starch in soluble sugars, as substratum for the resumption of growth in the spring. Seeking to better understanding the physiology of the plants in answers to events as the cli [...] matic variations, stresses and adaptation problems, this study was done in the Laboratory of Crop Physiology of Embrapa Temperate Climate, with the objective of describing a methodology for determination of concentrations of the soluble sugars (fructose, sorbitol, alpha-glucose, beta-glucose and sucrose), in tissues of fruit tree, through gaseous chromatography. The chromatograph used for the analyses of the sugars was the GAS CHROMATOGRAPH with the column of the type Packed Column J. K. of 3,2mm of diameter for 2m of length packed with Silicon IF-52 Uniport HP 80/100 mesh. Through the gaseous chromatography it is obtained efficiency and chromatographic resolution to soluble sugars determination, being this way, advantageous to use this methodology.

Alexandre Couto, Rodrigues; Flávio Gilberto, Herter; Valtair, Veríssimo; Geraldo, Chavarria; João Peterson Pereira, Gardin; Ângela Diniz, Campos.

44

A study on optimum insulation thicknesses of external walls in hot summer and cold winter zone of China  

Energy Technology Data Exchange (ETDEWEB)

The employ of thermal insulation is one of the most effective ways of building energy conservation for cooling and heating. Therefore, the selection of a proper insulation material and the determination of optimum insulation thickness are particularly vital. Four typical cities of Shanghai, Changsha, Shaoguan and Chengdu are selected to represent A, B, C and D subzone of hot summer and cold winter zone in China, respectively. The optimum thicknesses of five insulation materials including expanded polystyrene, extruded polystyrene, foamed polyurethane, perlite and foamed polyvinyl chloride are calculated with a typical residential wall using solar-air cooling and heating degree-days analysis and P{sub 1}-P{sub 2} economic model. And then, life cycle total costs, life cycle savings and payback periods are calculated based on life cycle cost analysis. Considering different orientations, surface colors, insulation materials and climates, optimum thicknesses of the five insulations vary from 0.053 to 0.236 m, and the payback periods vary from 1.9 to 4.7 years over a lifetime of 20 years. The maximum life cycle savings are 54.4 /m{sup 2} in Shanghai, 54.8 /m{sup 2} in Changsha and 41.5 /m{sup 2} in Shaoguan (with a deep-colored northeast wall), and 39.0 /m{sup 2} in Chengdu (with a light-colored northwest wall). Finally, an approach to analyze economical efficiency of insulation materials is developed, result shows that expanded polystyrene is the most economic insulation material of the five because of the highest life cycle saving and lowest payback period. (author)

Yu, Jinghua; Yang, Changzhi; Tian, Liwei; Liao, Dan [College of Civil Engineering, Hunan University, Changsha, Hunan 410082 (China)

2009-11-15

45

Seasonal succession of phytoplankton community and its relationship with environmental factors of North Temperate Zone water of the Zhalong Wetland, in China.  

Science.gov (United States)

A data set of phytoplankton community and environmental parameters in a hydrological integrity period, i.e. a poor water term, a medium term and a rich water term of North Temperate Zone climate, was analyzed in order to describe seasonal variation of phytoplankton community and its relationship with environmental variables in the Zhalong Wetland of China. The algal population of the Zhalong Wetland was not abundant, with a mean density of 5.08 × 10(7) cell/L (ranged from 4.54 × 10(7) cell/L in a poor term to 5.56 × 10(7) cell/L a medium term). However, its diversity was essentially limited to Cryptophyta, Bacillariophyta, Chlorophyta, Euglenophyta being the group with highest densities. There were considerable seasonal variations in phytoplankton composition. In general, the dominance of Bacillariophyceae was found in a medium term, which was higher than the other period (p < 0.05). The rich water period also showed Bacillariophyceae and Chlorophyta dominance while the phytoplankton was dominated by Cryptophyta erosa in a poor water term. 10 environmental variables, which were significant (p < 0.05) during the studied periods in one-way analysis of covariance, were selected to explore the relationship between phytoplankton structure and environmental factors by canonical correspondence analysis (CCA). The results of the CCA applied to the environmental factors indicated that water temperature (WT) and ammonia (NH3-N) significantly influenced the phytoplankton community (p < 0.05; Monte Carlo test of first constrained axis). Besides WT and NH3-N, the most discriminate physic-chemical variables were nitrite (NO2-N), suspend solid, nitrate (NO3-N), silicon dioxide (SiO2) and all the 10 physical-chemical parameters had a higher marginal effect and ?A in the series of constrained CCAs though they were not significant. PMID:24756328

Ma, Yun; Li, Guibai; Li, Jing; Zhou, Hao; Jiang, Bing

2014-05-01

46

Immune response to an endotoxin challenge involves multiple immune parameters and is consistent among the annual-cycle stages of a free-living temperate zone bird.  

Science.gov (United States)

Trade-offs between immune function and other physiological and behavioural processes are central in ecoimmunology, but one important problem is how to distinguish a reallocation of resources away from the immune system from a reallocation or redistribution within the immune system. While variation in baseline values of individual immune parameters is well established, studies in wild animals on multiple parameters during an immune response are lacking. It also remains to be tested whether and how immune responses correlate with baseline values that vary, for example, over the course of an annual cycle. We studied immunological responses to an endotoxin challenge in skylarks (Alauda arvensis), a partial migrant bird breeding in temperate zones. We compared birds injected with the endotoxin LPS with un-injected controls, characterizing immunological responses with leukocyte profiles, titres of lytic enzymes and natural antibodies, and concentrations of haptoglobin and heat shock proteins. We did this in five annual-cycle stages to test whether the response varied throughout the year. The endotoxin challenge affected six of 10 measured parameters. Lysis titres and proportions of heterophils increased; haptoglobin concentrations and proportions of lymphocytes, basophils and eosinophils decreased. The variable effects on different immune components demonstrate the complexity of an immune response. We found no evidence that the response differed between annual-cycle stages. The response was independent of baseline measures taken directly upon capture in the field, indicating that birds were facing no immunological ceiling when mounting an immune response. Values of five parameters collected under field conditions were significantly related to values taken under standardized laboratory conditions. We conclude that multiple parts of the immune system are modulated during an immunological response and that responses are not re-organized throughout the annual cycle. PMID:23531817

Hegemann, Arne; Matson, Kevin D; Versteegh, Maaike A; Villegas, Auxiliadora; Tieleman, B Irene

2013-07-15

47

A review on applying ventilated double-skin facade to buildings in hot-summer and cold-winter zone in China  

Energy Technology Data Exchange (ETDEWEB)

The need to energy conservation and sustainable development in buildings is causing a new interest towards passive solar systems. Among them, double-skin facade (DSF) proves to be extremely attractive and promising. DSF is building envelope formed by two layers of different glazing facades which are separated by a ventilated air cavity. The cavity of DSF is used to collect or evacuate the solar radiation absorbed by the facades, thereby improving the thermal comfort and the indoor air quality while conserving energy for heating and cooling. Being a technique developed for colder climates, DSF has been widely applied in commercial buildings across Europe. Nowadays buildings with DSF also appear in the hot-summer and cold-winter zone in China where the weather conditions in summer seem to be not so good for the application. In fact, the thermal analysis of the DSF system is essential to its application in such hot-summer zone. This paper seeks to describe the existing main research methods on the thermal performance of DSF and the shading devices. Problems and possibilities are concomitant. Applying ventilated DSF with controlled shading device system would be a new efficient way for the commercial buildings in the hot-summer and cold-winter zone to meet the task of sustainable building design in China. (author)

Zhou, Juan; Chen, Youming [School of Civil Engineering, Hunan University, Changsha, Hunan 410082 (China); Key Laboratory of Building Safety and Energy Efficiency, MOE (China)

2010-05-15

48

Primary production and microbial activity in the euphotic zone of Lake Baikal (Southern Basin) during late winter  

Science.gov (United States)

Three years of regular weekly/biweekly monitoring of seasonal changes in temperature, transparency, chlorophyll a (CHL) and bacteria [erythrosine-stained microscopic counts and cultivable colony forming units (CFUs)] at the vertical profile in the South basin of Lake Baikal (51°54'195?N, 105°04'235?E, depth 800 m) were evaluated. In more detail, the structure and function of phytoplankton and the microbial loop in the euphotic layer at the same site were investigated during the late-winter-early-spring period under the ice. The depth of euphotic zone (up to 1% of surface irradiation) was 35 to 40 m. Primary production was measured three times a week with the 14C method in 2, 10, 20, 30 and 40 m. Maximum production was found in 10 m, with lower values towards the surface (light inhibition) and towards the lower layers. The total production in cells larger than 1 ?m in the column (0-40 m) was 204-240 mg C d -1 m -2, 30-40% of it being in cells 1-3 ?m (mostly picocyanobacteria), which represented roughly 9% of the total chlorophyll a (estimated from pigment analyses). A major part of phytoplankton biomass was formed by diatoms ( Synedra acus Hust., Asterionella formosa Hass. and Stephanodiscus meyerii Genkal & Popovskaya). Total production (including extracellular, dissolved organic matter) was 235-387 mg C day -1 m -2, and the exudates were readily used by bacteria (particles 0.2-1 ?m). This part amounted to 1-5% of cellular production in 2 to 20 m and 11-77% of cellular production in 20-40 m, i.e., in light-limited layers. From 0 to 30 m, chlorophyll a concentration was 0.8 to 1.3 ?g l -1, wherefrom it decreased rapidly to 0.1 ?g l -1 towards the depth of 40 m. Bacteria (DAPI-stained microscopic counts) reached 0.5-1.4×10 6 ml -1; their cell volumes measured via image analysis were small (average 0.05 ?m -3), often not well countable when erythrosine stain was used. Bacterial biomasses were in the range of 6-21 ?g C l -1. Numbers of colony forming units (CFUs) on nutrient fish-agar were c. 3-4 orders lower than DAPI counts. The amounts of heterotrophic protists were low, whereby flagellates reached 6 to 87 ml -1 and ciliates, 0.2-1.2 ml -1 (mostly Oligotrichida). Bacterial production was measured in the same depths as primary production using 3H-thymidine (Thy) and 14C-leucine (Leu) uptake. Consistently, bacterial abundances, biomasses, thymidine and leucine production were higher by 30-50% in layers 2, 10 and 20 m compared with that in the deeper 30 and 40 m, where cellular primary production was negligible. Leucine uptake in the deeper layers was even three times lower than in the upper ones. From the comparison of primary and bacterial production, bacteria roughly use 20-40% of primary production during 24 h in the layers 2 to 20 m.

Straškrábová, V.; Izmest'yeva, L. R.; Maksimova, E. A.; Fietz, S.; Nedoma, J.; Borovec, J.; Kobanova, G. I.; Shchetinina, E. V.; Pislegina, E. V.

2005-04-01

49

Potential effects of climate change on the temperate zones of North and South America Potenciales efectos del cambio climático en zonas templadas de América del Norte y del Sur  

Directory of Open Access Journals (Sweden)

Full Text Available Under current conditions, large areas of temperate western North America and temperate southern South America have arid to subhumid climates that make them vulnerable to changes as a result of human-induced climate change. Predictions of climate change from global circulation models with a doubling of present atmospheric levels of CO2 suggest large changes in mean annual temperature and small to no changes in mean annual precipitation and the proportion of precipitation received during the summer. Our objective here was to evaluate how predictions of climate change from global circulation models will influence climatic patterns and by inference the distribution of temperate zone ecosystems in North and South America. Calculations of annual water deficits suggest that the area affected by very dry conditions will double as a result of climate change. This expansion will take place in the vicinity of the currently dry areas. Monthly water deficit calculations suggest that approximately half of the temperate zone on each continent is affected by at least one month of deficit. Under a doubled CO2 climate, these areas would expand to cover up to 77 % of the temperate zone of North America and up to 80 % of South America. The resulting changes to the current distribution of ecosystems will likely be an expansion of deserts at the expense of grasslands in North and South America and an expansion of grasslands at the expense of deciduous and boreal forest in North America. Our analyses assumed that future climatic changes will be encompassed by the predictions of our three doubled CO2 scenarios. The most likely situation is that actual changes, if they occur, will be different from our scenarios. Therefore, our analyses should be interpreted as indications of the sensitivity of portions of the North and South American temperate zones to increases in temperature. The key conclusion from our analyses is that any increase in temperature caused by climate change will result in expansion of the driest portions of both continentsBajo condiciones actuales, extensas áreas de las zonas templadas del oeste de América del Norte y del sur de América del Sur tienen regímenes climáticos áridos a subhúmedos, que son vulnerables a cambios climáticos inducidos por actividades humanas. Predicciones obtenidas a partir de modelos de circulación global bajo una duplicación del CO2 atmosférico sugieren grandes cambios en temperatura media anual, y cambios pequeños o nulos en la precipitación media anual y la proporción de precipitación estival. Nuestro objetivo fue evaluar cómo las predicciones de cambio climático obtenidas de modelos de circulación global influirán sobre los patrones climáticos, e inferir a partir de ello la distribución de los ecosistemas de las zonas templadas de América del Norte y del Sur. Cálculos de déficit hídrico anual sugieren que, debido al cambio climático, se duplicará el área afectada por condiciones muy secas. Esta expansión ocurrirá en las cercanías de las zonas áridas actuales. Cálculos mensuales de déficit hídrico sugieren que aproximadamente la mitad de la zona templada de cada continente se ve afectada por al menos un mes de déficit. Bajo un clima con doble CO2, estas áreas se expandirían y cubrirían hasta 77 % de las áreas templadas de América del Norte y hasta 80 % de América del Sur. Los cambios en la distribución de ecosistemas resultantes probablemente serán debidos a la expansión de los desiertos a expensas de los pastizales en América del Norte y del Sur, y la expansión de los pastizales a expensas de los bosques deciduos y boreales en América del Norte. Nuestros análisis asumen que los cambios climáticos futuros estarán abarcados por las predicciones de los tres escenarios de duplicación de CO2 que utilizamos. La situación más probable es que los cambios reales, si es que ocurren, serán distintos a nuestros escenarios. Por lo tanto, nuestros análisis deberán interpretarse como indicaciones de la sensibilidad de partes de las zonas

W.K. LAUENROTH

2004-09-01

50

Winter to summer evolution of pCO2 in surface water and air–sea CO2 flux in the seasonal ice zone of the Southern Ocean  

Directory of Open Access Journals (Sweden)

Full Text Available Partial pressure of CO2 (pCO2 in surface water and vertical profiles of the aqueous carbonate system were measured during austral summer in the Indian sector of the Southern Ocean (64–67° S, 32–58° E in January~2006 to understand the CO2 dynamics of seawater in the seasonal ice zone. Surface-water pCO2 ranged from 275 to 400 ?atm, and longitudinal variations reflected the dominant influence of water temperature and dilution by sea-ice meltwater between 32° and 40° E and biological productivity between 40° and 58° E. Using carbonate system data from the temperature minimum layer, we examined the winter-to-summer evolution of surface-water pCO2 and the factors affecting it. Our results indicate that pCO2 increased by as much as 32 ?atm, resulting mainly from the increase in water temperature. In synchrony with changes in sea ice concentration and surface-water pCO2, air–sea CO2 flux with considering the exchange of CO2 between sea ice and atmosphere, changed from ?1.1 to +0.9 mmol C m?2 day?1 between winter and summer. These results suggest that for the atmosphere, the seasonal ice zone acts as a CO2 sink in winter and a CO2 source in summer immediately after ice melt. Subsequent biological productivity likely decreases surface-water pCO2 and air–sea CO2 flux becomes negative, such that in summer the study area is a CO2 sink with respect to the atmosphere.

D. Nomura

2014-01-01

51

Citril finches during the winter: patterns of distribution, the role of pines and implications for the conservation of the species  

Digital Repository Infrastructure Vision for European Research (DRIVER)

[EN]: The Citril finch Serinus citrinella is a Paleartic endemic species that breeds in the subalpine mountain zones of western temperate Europe. The species seems to be suffering a serious decline in its northern range, mainly in the Black Forest and the NE of the Alps. Numerous reasons have been provided for this decline, but all of them have been related to breeding habitats. Given that the species undergoes an altitudinal migration and that during winter it may use very different habit...

Borras, A.; Senar, J. C.; Alba Sa?nchez, Francisca; Lo?pez Sa?ez, Jose? Antonio; Cabrera, J.; Colome?, X.; Cabrera, T.

2010-01-01

52

Elemental contents determination in two different zones of Mexico City on the 1987-88 and 1994-95 winters  

International Nuclear Information System (INIS)

During the 1987-1988 and 1994-1995 winters, there were taken samples of aerosols in Mexico City, in two different places, using an integral type of sampler which determines the total amount of suspended particulates; these samples were analyzed by the multi-element analysis technique called PIXE (Proton Induced X-ray Emission). One of the sites corresponds to the Alvaro Obregon area and the other to the Azcapotzalco area (a place near to the18 de Marzo Refinery). There were determined 16 elements, heavy metals, whose concentrations show differences for both sites and periods, standing out for this study the behavior of S, V and Pb. (Author)

1996-06-26

53

Tempering by Subsampling  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we demonstrate that tempering Markov chain Monte Carlo samplers for Bayesian models by recursively subsampling observations without replacement can improve the performance of baseline samplers in terms of effective sample size per computation. We present two tempering by subsampling algorithms, subsampled parallel tempering and subsampled tempered transitions. We provide an asymptotic analysis of the computational cost of tempering by subsampling, verify that t...

Meent, Jan-willem; Paige, Brooks; Wood, Frank

2014-01-01

54

Potential effects of climate change on the temperate zones of North and South America / Potenciales efectos del cambio climático en zonas templadas de América del Norte y del Sur  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Bajo condiciones actuales, extensas áreas de las zonas templadas del oeste de América del Norte y del sur de América del Sur tienen regímenes climáticos áridos a subhúmedos, que son vulnerables a cambios climáticos inducidos por actividades humanas. Predicciones obtenidas a partir de modelos de circ [...] ulación global bajo una duplicación del CO2 atmosférico sugieren grandes cambios en temperatura media anual, y cambios pequeños o nulos en la precipitación media anual y la proporción de precipitación estival. Nuestro objetivo fue evaluar cómo las predicciones de cambio climático obtenidas de modelos de circulación global influirán sobre los patrones climáticos, e inferir a partir de ello la distribución de los ecosistemas de las zonas templadas de América del Norte y del Sur. Cálculos de déficit hídrico anual sugieren que, debido al cambio climático, se duplicará el área afectada por condiciones muy secas. Esta expansión ocurrirá en las cercanías de las zonas áridas actuales. Cálculos mensuales de déficit hídrico sugieren que aproximadamente la mitad de la zona templada de cada continente se ve afectada por al menos un mes de déficit. Bajo un clima con doble CO2, estas áreas se expandirían y cubrirían hasta 77 % de las áreas templadas de América del Norte y hasta 80 % de América del Sur. Los cambios en la distribución de ecosistemas resultantes probablemente serán debidos a la expansión de los desiertos a expensas de los pastizales en América del Norte y del Sur, y la expansión de los pastizales a expensas de los bosques deciduos y boreales en América del Norte. Nuestros análisis asumen que los cambios climáticos futuros estarán abarcados por las predicciones de los tres escenarios de duplicación de CO2 que utilizamos. La situación más probable es que los cambios reales, si es que ocurren, serán distintos a nuestros escenarios. Por lo tanto, nuestros análisis deberán interpretarse como indicaciones de la sensibilidad de partes de las zonas templadas de América del Norte y del Sur a aumentos de temperatura. La principal conclusión de nuestros análisis es que cualquier aumento de temperatura debido a cambios climáticos resultará en una expansión de las porciones más áridas de ambos continentes Abstract in english Under current conditions, large areas of temperate western North America and temperate southern South America have arid to subhumid climates that make them vulnerable to changes as a result of human-induced climate change. Predictions of climate change from global circulation models with a doubling [...] of present atmospheric levels of CO2 suggest large changes in mean annual temperature and small to no changes in mean annual precipitation and the proportion of precipitation received during the summer. Our objective here was to evaluate how predictions of climate change from global circulation models will influence climatic patterns and by inference the distribution of temperate zone ecosystems in North and South America. Calculations of annual water deficits suggest that the area affected by very dry conditions will double as a result of climate change. This expansion will take place in the vicinity of the currently dry areas. Monthly water deficit calculations suggest that approximately half of the temperate zone on each continent is affected by at least one month of deficit. Under a doubled CO2 climate, these areas would expand to cover up to 77 % of the temperate zone of North America and up to 80 % of South America. The resulting changes to the current distribution of ecosystems will likely be an expansion of deserts at the expense of grasslands in North and South America and an expansion of grasslands at the expense of deciduous and boreal forest in North America. Our analyses assumed that future climatic changes will be encompassed by the predictions of our three doubled CO2 scenarios. The most likely situation is that actual changes, if they occur, will be different f

W.K., LAUENROTH; H.E., EPSTEIN; J.M., PARUELO; I.C., BURKE; M.R., AGUIAR; O.E., SALA.

55

Serial tempering without exchange  

Science.gov (United States)

Serial tempering is a computational method that turns the temperature T (or more generally any independent ? parameter) into a dynamical variable. It is shown that, under conditions for which this variable is fast, serial tempering is equivalent to the umbrella sampling method with a single effective potential. This equivalence is demonstrated using both a small one-dimensional system and a small solvated peptide. The suggestion is then made to replace the serial tempering protocol with the equivalent umbrella sampling calculation. This approach, serial tempering without exchange (STeWiE), has the same performance as serial tempering in the limit that exchanges are frequent, is simpler to implement, and has fewer adjustable parameters than conventional serial tempering. The equivalence of serial tempering and STeWiE also provides a convenient route for estimating and optimizing the performance of serial tempering simulations and other generalized-ensemble methods.

Nymeyer, Hugh

2010-09-01

56

Temperature characteristics of winter roost-sites for birds and mammals: tree cavities and anthropogenic alternatives.  

Science.gov (United States)

The microclimate of potential roost-sites is likely to be a crucial determinant in the optimal roost-site selection of endotherms, in particular during the winter season of temperate zones. Available roost-sites for birds and mammals in European high trunk orchards are mainly tree cavities, wood stacks and artificial nest boxes. However, little is known about the microclimatic patterns inside cavities and thermal advantages of using these winter roost-sites. Here, we simultaneously investigate the thermal patterns of winter roost-sites in relation to winter ambient temperature and their insulation capacity. While tree cavities and wood stacks strongly buffered the daily cycle of temperature changes, nest boxes showed low buffering capacity. The buffering effect of tree cavities was stronger at extreme ambient temperatures compared to temperatures around zero. Heat sources inside roosts amplified ? T (i.e., the difference between inside and outside temperatures), particularly in the closed roosts of nest boxes and tree cavities, and less in the open wood stacks with stronger circulation of air. Positive ? T due to the installation of a heat source increased in cold ambient temperatures. These results suggest that orchard habitats in winter show a spatiotemporal mosaic of sites providing different thermal benefits varying over time and in relation to ambient temperatures. At cold temperatures tree cavities provide significantly higher thermal benefits than nest boxes or wood stacks. Thus, in winter ecology of hole-using endotherms, the availability of tree cavities may be an important characteristic of winter habitat quality. PMID:23423627

Grüebler, Martin U; Widmer, Silv; Korner-Nievergelt, Fränzi; Naef-Daenzer, Beat

2014-07-01

57

Spatial variation of biomass of seaweed assemblages in the temperate-tropical transition zone of Baja California Peninsula, Mexico Variación espacial de la biomasa de macroalgas en una zona de transición templado-tropical en la Península de Baja California, México  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Biomass changes of seaweed assemblages in four locations in a temperate-tropical transition zone were analyzed between October 1996 and August 1997. Locations with lower temperature, a high index of upwelling, and high quantities of hard substrate presented the largest values of biomass of seaweed (El Cardoncito (7.2 kg m-2), and Las Boyitas (6.2 kg m-2)) and the biggest quantity of species of temperate affinity. Conversely, El Datilito (0.366 kg m-2), with a higher temperature, no evidence o...

Margarita Casas Valdez; Ruth Noemí Aguila Ramírez

2008-01-01

58

Spatial and temporal changes in invertebrate assemblage structure from the entrance to deep-cave zone of a temperate marble cave  

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Full Text Available Seasonality in surface weather results in seasonal temperature and humidity changes in caves. Ecological and physiological differences among trogloxenes, troglophiles, and troglobionts result in species-dependent responses to this variability. To investigate these responses, we conducted five biological inventories in a marble cave in the Sierra Nevada Range, California, USA between May and December 2010. The cave was divided into six quadrats and temperature was continuously logged in each (humidity was logged at the entrance and in the deep cave. With increasing distance from the entrance, temperature changes were increasingly attenuated and lagged relative to surface temperature. Linear regressions were created to determine the relationship between measured environmental variables and diversity for cavernicoles (troglobionts and troglophiles and trogloxenes cave– wide and in the transition zone. Diversity for cavernicoles and trogloxenes peaked in the entrance and deep cave zones, respectively. Quadrat, date, 2-week antecedent temperature average, 2-week antecedent temperature range, and trogloxene abundance explained 76% of cavernicole diversity variability. Quadrat explained 55% of trogloxene diversity variability. In the transition zone, trogloxene abundance explained 26% of cavernicole variability and 2-week antecedent temperature and 2-week antecedent temperature range explained 40% of trogloxene variability. In the transition zone, trogloxene diversity was inversely related to 2-week antecedent temperature average and 2-week antecedent temperature range, suggesting that species were moving into the transition zone when temperature was most stable. In a CCA of cavernicoles distribution data and environmental variables, 35% of variation in species-specific distributions was attributable to quadrat, and non-significant percentages were explained by date and environmental variables. Differences in assemblage structure among quadrats were largely due to differences between distributions of trogloxenes and cavernicoles, but responses varied among species. Differences are likely due to ecological niche width, physiological constraints, and competition.

Benjamin W. Tobin

2013-09-01

59

Automatic Geographic Object Based Mapping of Streambed and Riparian Zone Extent from LiDAR Data in a Temperate Rural Urban Environment, Australia  

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Full Text Available This research presents a time-effective approach for mapping streambed and riparian zone extent from high spatial resolution LiDAR derived products, i.e., digital terrain model, terrain slope and plant projective cover. Geographic object based image analysis (GEOBIA has proven useful for feature extraction from high spatial resolution image data because of the capacity to reduce effects of reflectance variations of pixels making up individual objects and to include contextual and shape information. This functionality increases the likelihood of developing transferable and automated mapping approaches. LiDAR data covered parts of the Werribee Catchment in Victoria, Australia, which is characterized by urban, agricultural, and forested land cover types. Field data of streamside vegetation structure and physical form properties were used for both calibration of the mapping routines and validation of the mapping results. To improve the transferability of the rule set, the GEOBIA approach was developed for an area representing different riparian zone environments, i.e., urbanized, agricultural and hilly forested areas. Results show that mapping streambed extent (R2 = 0.93, RMSE = 3.6 m, n = 35 and riparian zone extent (R2 = 0.74, RMSE = 3.9, n = 35 from LiDAR derived products can be automated using GEOBIA to enable derivation of spatial information in an accurate and time-effective manner suited for natural resource management agencies.

Stuart Phinn

2011-05-01

60

Winter Weather  

Science.gov (United States)

... Statistics Training Publications Newsroom Small Business Anti-Retaliation Winter Storms Plan. Equip. Train To prevent injuries, illnesses and Fatalities during winter storms. Introduction Wind Chill Temperature Be Prepared Hazards/ ...

 
 
 
 
61

The impacts of drainage, nutrient status and management practice on the full carbon balance of grasslands on organic soils in a maritime temperate zone  

Directory of Open Access Journals (Sweden)

Full Text Available Temperate grasslands on organic soils are diverse due to edaphic properties but also to regional management practices and this heterogeneity is reflected in the wide range of greenhouse gas flux values reported in the literature. In Ireland, most grasslands on organic soils were drained several decades ago and are managed as extensive pastures with little or no fertilisation. This study describes a two-year study of the net ecosystem carbon balance (NECB of two such sites. We determined greenhouse gas (GHG fluxes and waterborne carbon emissions in a nutrient rich grassland and compared it with values measured from two nutrient poor organic soils: a deep drained and a shallow drained site. GHG fluxes (CO2, CH4 and N2O were determined using the chamber technique, and fluvial C fluxes were estimated by combining drainage water concentrations and flows. The nutrient rich site was an annual source of CO2 (NEE 233 g C m?2yr?1, CH4 neutral, and a small source of nitrous oxide (1.6 kg N2O-N ha?1yr?1. NEE at the shallow drained site was ?89 and ?99 g C m?2yr?1 in Years 1 and 2 respectively, and NEE at the deep drained site was +85 and ?26 g C m?2yr?1 respectively. Low CH4 emissions (1.3 g C m?2yr?1 were recorded at the shallow drained nutrient poor site. Fluvial exports from the nutrient rich site totalled 69.8 g C m?2yr?1 with 54% as dissolved organic C (DOC. Waterborne C losses from the nutrient poor site reflected differences in annual runoff totalling 44 g C m?2yr?1 in Year 1 and 30.8 g C m?2yr?1 in Year 2. The NECB of the nutrient rich grassland was 663 g C m?2yr?1 with biomass exports being the major component accounting for 53%. The NECB of the nutrient poor deep drained site was less than half of the nutrient rich site (2 year mean 267 g C m?2yr?1. Although NEE at the nutrient poor shallow drained site was negative in both years, high biomass export meant it was a net C source (2 year mean NECB 103 g C m?2yr?1. While the impacts of the nutrient and drainage status on NEE, biomass exports and fluvial C losses were confirmed, inter-regional differences in management practice and climate are also significant factors which impact on the overall NECB of these ecosystems. Contrary to expectation, the NECB of nutrient poor drained organic soils under grasslands is not necessarily a large C source and this has implications for Ireland's choice of national GHG inventory reporting methodologies. This study can also aid the development of strategies to deliver reduced emissions tailored to local grassland types.

F. Renou-Wilson

2014-04-01

62

Understory bamboo discrimination using a winter image  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, a new approach is presented that combines forest phenology and Landsat vegetation indices to estimate evergreen understory bamboo coverage in a mixed temperate forest. It was found that vegetation indices, especially the normalized difference vegetation index (NDVI) derived from leaf-off (winter) images were significantly correlated with percent understory bamboo cover for both deciduous and mixed coniferous/deciduous forests. Winter NDVI was used to map bamboo coverage using a...

2009-01-01

63

Cell mediated immunity in Antarctic wintering personnel; 1984-1992.  

Science.gov (United States)

Cell-mediated immune responses were studied in 12 Antarctic and sub-Antarctic wintering groups at quarterly intervals over the period 1984-1992, using the cutaneous CMI Multitest. These populations are among the most isolated on earth. While the sub-Antarctic population at Macquarie Island had levels of responsiveness and hypoergy (9%) comparable to healthy populations in temperate zones, the Antarctic Continental group showed a level of hypoergy of 36%. There was no seasonal variation in the pattern of responses. It is concluded that the extreme and isolated environment and stress factors are responsible for the decreased immunological responsiveness but the mechanisms are presently unclear. On review, one factor appears to be perceived anxiety. The high rate of hypoergy in Antarctica, where medical care is limited, may have health implications. These groups provide an excellent analogue for immunological investigations in longer term space flight. PMID:7493767

Muller, H K; Lugg, D J; Quinn, D

1995-08-01

64

Winter Wonderlands  

Science.gov (United States)

Listening to people complain about the hardships of winter and the dreariness of the nearly constant gray sky prompted the author to help her sixth graders recognize and appreciate the beauty that surrounds them for nearly five months of the year in western New York. The author opines that if students could see things more artistically, the winter…

Coy, Mary

2011-01-01

65

Preliminary study of the effects of juvenile spacing on wildlife habitat use during winter in the interior douglas-fir zone of British Columbia. Research report No. RR 88002-CA  

Energy Technology Data Exchange (ETDEWEB)

Juvenile spacing (non-commercial thinning) of overstocked regeneration has silvicultural benefits and has become a popular stand-tending practice in the interior of British Columbia. In view of the increasing area subject to juvenile spacing, concern is mounting about the potential impact on wildlife. This study documents, in a preliminary way, how spacing affects winter habitat use of common wildlife species in the interior Douglas-fir zone. Six blocks were examined that were spaced during the summer and fall of 1986 and 1987 near Big Lake in the 100 Mile House Forest district. The study examined the impact of juvenile spacing on the degree of winter habitat used by snowshoe hare, red squirrel, fox, coyote, lynx, mule deer, and moose; examined animal use of unspaced strips; explored the relationship between animal use and distance from a spaced-unspaced edge; and assessed animal use of man-made trails through spacing slash.

1988-01-01

66

Citril finches during the winter: patterns of distribution, the role of pines and implications for the conservation of the species.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Citril finch Serinus citrinella is a Paleartic endemic species that breeds in the subalpine mountain zones of western temperate Europe. The species seems to be suffering a serious decline in its northern range, mainly in the Black Forest and the NE of the Alps. Numerous reasons have been provided for this decline, but all of them have been related to breeding habitats. Given that the species undergoes an altitu¬dinal migration and that during winter it may use very different habitats, a ...

2010-01-01

67

Potential effects of climate change on the temperate zones of North and South America Potenciales efectos del cambio climático en zonas templadas de América del Norte y del Sur  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Under current conditions, large areas of temperate western North America and temperate southern South America have arid to subhumid climates that make them vulnerable to changes as a result of human-induced climate change. Predictions of climate change from global circulation models with a doubling of present atmospheric levels of CO2 suggest large changes in mean annual temperature and small to no changes in mean annual precipitation and the proportion of precipitation received during the su...

Lauenroth, W. K.; Epstein, H. E.; Paruelo, J. M.; Burke, I. C.; Aguiar, M. R.; Sala, O. E.

2004-01-01

68

Temperate Lakes Discovered on Titan  

Science.gov (United States)

We have discovered two temperate lakes on Titan using Cassini's Visual and Infrared Mapping Spectrometer (VIMS). Three key features help to identify these surface features as lakes: morphology, albedo, and specular reflection. The presence of lakes at the mid-latitudes mean liquid can accumulate and remain stable outside of the poles. We first identify a lake surface by looking for possible shorelines with a lacustrine morphology. Then, we apply a simple atmospheric correction that produces an approximate surface albedo. Next, we prepare cylindrical projection maps of the brightness of the sky as seen from any points on the surface to identify specular reflections. Our techniques can then be applied to other areas, such as Arrakis Planitia, to test for liquid. Currently, all the known lakes on Titan are concentrated at the poles. Lakes have been suggested in the tropic zone by Griffith et al. Our discovery of non-transient, temperate lakes has important implications for Titan's hydrologic cycle. Clouds have been recorded accumulating in the mid-latitudes and areas have been darkened by rainfall but later brightened after evaporation (Turtle et al. 2011). Stable temperate lakes would affect total rainfall, liquid accumulation, evaporation rates, and infiltration. Polaznik Macula (Figure 1) is a great candidate for lake filling, evaporation rates, and stability. References: Griffith, C., et al.: "Evidence for Lakes on Titan's Tropical Surface". AAS/Division for Planetary Sciences Meeting Abstracts #42, Vol. 42, pp. 1077, 2010. Turtle, E. P., et al.: "Rapid and Extensive Surface Changes Near Titan's Equator: Evidence of April Showers". Science, Vol. 331, pp. 1414-, 2011. Figure 1: Polaznik Macula is the large, dark area central to the figure. The encircled dark blue areas represent positively identified lake regions in the T66 flyby. The light blue areas represent lake candidates still under analysis. The green circle marks a non-lake surface feature enclosed by a lake.

Vixie, Graham; Barnes, Jason W.; Jackson, Brian; Wilson, Paul

2012-04-01

69

The nitrate leached below maize root zone is available for deep-rooted wheat in winter wheat-summer maize rotation in the North China Plain.  

Science.gov (United States)

In winter wheat (Triticum aestivum L.)-summer maize (Zea mays L.) rotation system in the North China Plain, maize roots do not extend beyond 1.2 m in the vertical soil profile, but wheat roots can reach up to 2.0 m. Increases in soil nitrate content at maize harvest and significant reductions after winter wheat harvest were observed in the 1.4-2.0 m depth under field conditions. The recovery of 15N isotope (calcium nitrate) from various (1.0, 1.2, 1.4, 1.6, 1.8 and 2.0 m) soil depths showed that deep-rooting winter wheat could use soil nitrate up to the 2.0 m depth. This accounted partially, for the reduced nitrate in the 1.4-2.0 m depth of the soil after harvest of wheat in the rotation system. PMID:17692443

Zhou, Shun-Li; Wu, Yong-Cheng; Wang, Zhi-Min; Lu, Lai-Qing; Wang, Run-Zheng

2008-04-01

70

Patterns of tree seedling mortality in a temperate-mediterranean transition zone forest in Chile / Patrones en la mortalidad de plántulas de especies arbóreas de un bosque de la transición templado-mediterránea de Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish La mortalidad de las plántulas es el resultado de una gama de procesos y agentes que pueden variar espacial y temporalmente en los ecosistemas forestales. En este estudio cuantificamos la emergencia y mortalidad de plántulas mes a mes, por un período de dos años en un bosque situado en la zona de tr [...] ansición entre la región mediterránea y templada de Chile. Pretendimos dilucidar si las especies sobreviven en forma diferencial a la disminución estacional en la disponibilidad de agua, a la variación espacial en la disponibilidad de luz y a la densidad local de plántulas. Las especies más abundantes en el banco de plántulas son la esclerófila Cryptocarya alba (61%) y la especie templada Aextoxicon punctatum (29%). Del total de 504 plántulas emergidas durante el estudio, murieron 279, lo que corresponde a un 55,4 %. Cuatro de las especies menos abundantes (Persea lingue, Peumus boldus, Nothofagus obliqua y Luma apiculata) sufrieron un 100 % de mortalidad de plántulas emergidas durante los dos años. La mortalidad de A.punctatum evidenció una marcada estacionalidad, con tasas elevadas durante la estación más seca (verano), pero este patrón fue mucho menos evidente en C. alba. Un análisis de regresión múltiple mostró que la luz no afectó la mortalidad de A. punctatum ni de C. alba. El mismo análisis demostró que existe un efecto densodependiente conespecífico sobre la mortalidad de A. punctatum, en contraste con C. alba, cuya mortalidad no fue afectada por la densidad conespecífica de plántulas. Efectos densodependientes comunitarios se descartan para ambas especies. La presente investigación muestra que los factores críticos varían espacial y temporalmente determinando diferencias interespecíficas en la supervivencia de plántulas de especies nativas en este tipo de ecosistema. Abstract in english Seedling mortality in forests is the net result of an array of processes that vary spatially and temporally. We quantified emergence and mortality of seedlings at monthly intervals for two years, in a forest situated in the transition zone between the Mediterranean and temperate regions of Chile. We [...] aimed to determine if survival of species responded differentially to seasonal water availability, to the spatial variation in light availability and to seedling density. The commonest species in the seedling bank were the Mediterranean-climate species Cryptocarya alba (61%) and the temperate-climate species Aextoxicon punctatum (29%). 279 of the 504 new seedlings that emerged during the two-year study died during the same period, corresponding to 55,4% mortality. Four of the less common species (Persea lingue, Peumus boldus, Nothofagus obliqua and Luma apiculata) suffered 100 % mortality of new recruits. Mortality of A. punctatum showed a marked seasonal pattern, with high mortality during the dry summer months. In contrast, mortality of the Mediterranean-climate species C. alba was more evenly distributed throughout the year. Multiple regressions showed that light availability had no significant effect on mortality of A. punctatum or C. alba. The same analysis revealed that survival of A. punctatum was negatively affected by conspecific seedling density, but this density-dependent effect was not found for C. alba. Heterospecific density-dependent effects were not found, i.e. mortality of neither species was affected by local density of seedlings of other species. This study shows that spatial and temporal variation in critical factors shapes interspecific variation in seedling mortality in this forest.

PARADA, TERESA; LUSK, CHRISTOPHER H..

71

Patterns of tree seedling mortality in a temperate-mediterranean transition zone forest in Chile Patrones en la mortalidad de plántulas de especies arbóreas de un bosque de la transición templado-mediterránea de Chile  

Directory of Open Access Journals (Sweden)

Full Text Available Seedling mortality in forests is the net result of an array of processes that vary spatially and temporally. We quantified emergence and mortality of seedlings at monthly intervals for two years, in a forest situated in the transition zone between the Mediterranean and temperate regions of Chile. We aimed to determine if survival of species responded differentially to seasonal water availability, to the spatial variation in light availability and to seedling density. The commonest species in the seedling bank were the Mediterranean-climate species Cryptocarya alba (61% and the temperate-climate species Aextoxicon punctatum (29%. 279 of the 504 new seedlings that emerged during the two-year study died during the same period, corresponding to 55,4% mortality. Four of the less common species (Persea lingue, Peumus boldus, Nothofagus obliqua and Luma apiculata suffered 100 % mortality of new recruits. Mortality of A. punctatum showed a marked seasonal pattern, with high mortality during the dry summer months. In contrast, mortality of the Mediterranean-climate species C. alba was more evenly distributed throughout the year. Multiple regressions showed that light availability had no significant effect on mortality of A. punctatum or C. alba. The same analysis revealed that survival of A. punctatum was negatively affected by conspecific seedling density, but this density-dependent effect was not found for C. alba. Heterospecific density-dependent effects were not found, i.e. mortality of neither species was affected by local density of seedlings of other species. This study shows that spatial and temporal variation in critical factors shapes interspecific variation in seedling mortality in this forest.La mortalidad de las plántulas es el resultado de una gama de procesos y agentes que pueden variar espacial y temporalmente en los ecosistemas forestales. En este estudio cuantificamos la emergencia y mortalidad de plántulas mes a mes, por un período de dos años en un bosque situado en la zona de transición entre la región mediterránea y templada de Chile. Pretendimos dilucidar si las especies sobreviven en forma diferencial a la disminución estacional en la disponibilidad de agua, a la variación espacial en la disponibilidad de luz y a la densidad local de plántulas. Las especies más abundantes en el banco de plántulas son la esclerófila Cryptocarya alba (61% y la especie templada Aextoxicon punctatum (29%. Del total de 504 plántulas emergidas durante el estudio, murieron 279, lo que corresponde a un 55,4 %. Cuatro de las especies menos abundantes (Persea lingue, Peumus boldus, Nothofagus obliqua y Luma apiculata sufrieron un 100 % de mortalidad de plántulas emergidas durante los dos años. La mortalidad de A.punctatum evidenció una marcada estacionalidad, con tasas elevadas durante la estación más seca (verano, pero este patrón fue mucho menos evidente en C. alba. Un análisis de regresión múltiple mostró que la luz no afectó la mortalidad de A. punctatum ni de C. alba. El mismo análisis demostró que existe un efecto densodependiente conespecífico sobre la mortalidad de A. punctatum, en contraste con C. alba, cuya mortalidad no fue afectada por la densidad conespecífica de plántulas. Efectos densodependientes comunitarios se descartan para ambas especies. La presente investigación muestra que los factores críticos varían espacial y temporalmente determinando diferencias interespecíficas en la supervivencia de plántulas de especies nativas en este tipo de ecosistema.

TERESA PARADA

2011-01-01

72

Hot wire TIG temper bead welding for nuclear repairs  

International Nuclear Information System (INIS)

A preliminary assessment has been carried out to determine the suitability of the hot wire tungsten inert gas (TIG) welding process for the repair of thick section, ferritic steel nuclear pressure vessels. The objective has been to identify a hot wire TIG temper bead procedure, suitable for repairs without post weld heat treatment. This procedure involves depositing two weld layers with carefully selected welding parameters such that overlapping thermal cycles produce a refined and tempered heat affected zone, HAZ, microstructure. (author)

1989-01-01

73

Surviving Winter  

Science.gov (United States)

In this lesson designed to enhance literacy skills, students learn about the varied physical and behavioral adaptations that animals rely on to help them survive changing environmental conditions, such as the arrival of winter.

Foundation, Wgbh E.

2010-12-13

74

Tempering of Fenin Martensite.  

Science.gov (United States)

The tempering behavior of ternary iron-nickel-nitrogen martensic specimens (approx. 13.5 at. percent Ni, approx. 4.7 at. percent N, approx. 4.9 atoms per 100 metal atoms) was investigated in the temperature range 270 to 670 K. The analysis of the correspo...

C. Liu A. Boettger E. J. Mittemeijer

1990-01-01

75

Protective coating of austenitic steel using robotized GMAW temper-bead technique  

International Nuclear Information System (INIS)

This paper summarises experimental results obtained in a study of GMAW temper-bead on low alloyed steel with austenitic consumables. Temper-bead on low alloyed steel with austenitic consumables is mainly used for repairing operations of heavy components such as vessel reactor of nuclear power plants. Experimental work aims at showing the performance of GMAW compared to GTAW and the consequences of GMAW temper-bead on 2OMND5 heat affected zones. (authors)

2009-01-01

76

Winter Storms  

Science.gov (United States)

This website offers general background about winter storms as well as interactive activities designed to teach visitors about the characteristics and generation of these storms. It also offers a teacher's guide to using this site and links to other weather-related pages.

77

Winter's Tale  

Science.gov (United States)

This resource explores winter weather and frozen precipitation. Precipitation (in the form of snow, sleet and freezing rain) is explained, as are a variety of cloud types and generation, the nature and generation of the jet stream, and the aesthetic wonders of frozen water. A bibliography is also provided.

78

Comparison of Seasonal Soil Microbial Process in Snow-Covered Temperate Ecosystems of Northern China  

Science.gov (United States)

More than half of the earth's terrestrial surface currently experiences seasonal snow cover and soil frost. Winter compositional and functional investigations in soil microbial community are frequently conducted in alpine tundra and boreal forest ecosystems. However, little information on winter microbial biogeochemistry is known from seasonally snow-covered temperate ecosystems. As decomposer microbes may differ in their ability/strategy to efficiently use soil organic carbon (SOC) within different phases of the year, understanding seasonal microbial process will increase our knowledge of biogeochemical cycling from the aspect of decomposition rates and corresponding nutrient dynamics. In this study, we measured soil microbial biomass, community composition and potential SOC mineralization rates in winter and summer, from six temperate ecosystems in northern China. Our results showed a clear pattern of increased microbial biomass C to nitrogen (N) ratio in most winter soils. Concurrently, a shift in soil microbial community composition occurred with higher fungal to bacterial biomass ratio and gram negative (G-) to gram positive (G+) bacterial biomass ratio in winter than in summer. Furthermore, potential SOC mineralization rate was higher in winter than in summer. Our study demonstrated a distinct transition of microbial community structure and function from winter to summer in temperate snow-covered ecosystems. Microbial N immobilization in winter may not be the major contributor for plant growth in the following spring.

Zhang, Xinyue; Wang, Wei; Chen, Weile; Zhang, Naili; Zeng, Hui

2014-01-01

79

Effects of juvenile spacing on wildlife habitat use during winter in the interior douglas-fir zone of British Columbia. Research report No. RR 89003-CA  

Energy Technology Data Exchange (ETDEWEB)

Juvenile spacing is a widely used stand-tending practice in the interior of British Columbia. While spacing is silviculturally beneficial, little research has directly assessed the positive and negative impacts on wildlife in various forest subzones. To address this problem in one specific subzone, a preliminary study was conducted in the 100 Mile House Forest District in winter 1987/88. Six blocks of multi-layered, mature interior Douglas-fir forests were juvenile spaced in the fall of 1986 and 1987 to demonstrate a variety of spacing densities and prescriptions such as minimizing slash depth, making trails, and leaving unspaced strips of regeneration within the block. These blocks were used to study the effects of spacing on habitat use by mule deer, snowshoe hare, red squirrel, fox, coyote, and moose. The study during 1988/89 collected more data to consolidate and extend the results and conclusions found by preliminary investigation.

Waterhouse, M.J.; Armleder, H.M.; Dawson, R.J.

1990-01-01

80

Off-season uptake of nitrogen in temperate heath vegetation  

DEFF Research Database (Denmark)

Off-season ecosystem processes is becoming an area of increasing interest, being important when considering annual nitrogen and carbon budgets. The general assumption that physiological activity in soil microorganisms as well as vegetation is low during winter may not be justified. In this field study we show that northern temperate coastal heath vegetation has a significant uptake potential for nitrogen, both in the form of ammonium and as glycine, throughout the non-growing season. We used 15N ammonium and 2*(13C)15N glycine as nutrient tracer. This was injected into the soil two times during winter and once at spring. The winter temperatures were similar to those of average winter in the northern temperate region of Europe, with only few days of soil temperatures below zero and a winter mean of 2.4 °C. The vegetation, consisting of the evergreen dwarf shrub Calluna vulgaris (L.), the deciduous dwarf shrub Salix arenaria (L.) and the graminoids Carex arenaria (L.) and Deschampsia flexuosa (L.), showed root uptake of both forms of nitrogen, both one day after labelling and after a month. Translocation of the labelled nitrogen to shoots was generally evident after one month and increased as spring approached, with different translocation strategies in the three plant functional types. Furthermore, shoot total nitrogen concentration increased in all plant types, but only the graminoids and, eventually, S. arenaria showed shoot growth during winter. Our study suggests that plant nitrogen uptake can cause increasing nitrogen concentration in shoot tissue from fall to spring. To our knowledge this is one of the first studies of plant nitrogen uptake during nongrowing season at a temperate heath. Our results show that the nitrogen uptake is in the same order of magnitude as summer uptake in other types of ecosystems in the temperate/boreal region. These results suggest that plant nitrogen uptake during winter should be included in the annual nitrogen budgets of heath ecosystems, and that the view of plant nutrient uptake as low in this climatic region during winter should be revised. Furthermore, these results should be taken into account when ecosystem responses to climatic changes such as warming are evaluated.

Andresen, Louise Christoffersen; Michelsen, Anders

2004-01-01

 
 
 
 
81

Environmental Predictors of Seasonal Influenza Epidemics across Temperate and Tropical Climates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-...

Tamerius, James D.; Shaman, Jeffrey; Alonso, Wladmir J.; Bloom-feshbach, Kimberly; Uejio, Christopher K.; Comrie, Andrew; Viboud, Ce?cile

2013-01-01

82

STUDY OF PRODUCTIVITIES VARIETIES OF WINTER BARLEY ????????????? ??????????? ??????? ??????  

Directory of Open Access Journals (Sweden)

Full Text Available The article presents the data of the yield of winter barley varieties various breeding institutions in conditions of the South zone of the Krasnodar region, as well as the analysis of selected indicators of yield structure elements

Repko N. V.

2013-09-01

83

Semipurity of tempered Deligne cohomology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we define the formal and tempered Deligne cohomology groups, that are obtained by applying the Deligne complex functor to the complexes of formal differential forms and tempered currents respectively. We then prove the existence of a duality between them, a vanishing theorem for the former and a semipurity property for the latter. The motivation of this results comes from the study of covariant arithmetic Chow groups. The semi-purity property of tempered Deligne cohomology impli...

2007-01-01

84

Semipurity of tempered Deligne cohomology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we define the formal and tempered Deligne cohomology groups, that are obtained by applying the Deligne complex functor to the complexes of formal differential forms and tempered currents respectively. We then prove the existence of a duality between them, a vanishing theorem for the former and a semipurity property for the latter. The motivation of these results comes from the study of covariant arithmetic Chow groups. The semi-purity property of tempered Delig...

Gil, J. I. Burgos

2010-01-01

85

Carbon sinks in temperate forests  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In addition to being scientifically exciting, commercially important, and environmentally essential, temperate forests have also become a key diplomatic item in international climate negotiations as potential sinks for carbon. This review presents the methods used to estimate carbon sequestration, identifies the constraints and opportunities for carbon sequestration in temperate forests, addresses the issues raised by the monitoring of carbon sequestration, and analyzes uncertainties pertaini...

2001-01-01

86

Tempered stable and tempered infinitely divisible GARCH models  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper, we introduce a new GARCH model with an infinitely divisible distributed innovation, referred to as the rapidly decreasing tempered stable (RDTS) GARCH model. This model allows the description of some stylized empirical facts observed for stock and index returns, such as volatility clustering, the non-zero skewness and excess kurtosis for the residual distribution. Furthermore, we review the classical tempered stable (CTS) GARCH model, which has similar statistical properties. B...

Kim, Young Shin; Rachev, Svetlozar T.; Bianchi, Michele Leonardo; Fabozzi, Frank J.

2011-01-01

87

Transfer parameter values in temperate forest ecosystems: a review  

International Nuclear Information System (INIS)

Compared to agricultural lands, forests are complex ecosystems as they can involve diverse plant species associations, several vegetative strata (overstorey, shrubs, herbaceous and other annual plant layer) and multi-layered soil profiles (forest floor, hemi-organic and mineral layers). A high degree of variability is thus generally observed in radionuclide transfers and redistribution patterns in contaminated forests. In the long term, the soil compartment represents the major reservoir of radionuclides which can give rise to long-term plant and hence food contamination. For practical reasons, the contamination of various specific forest products has commonly been quantified using the aggregated transfer factor (Tag in m2 kg-1) which integrates various environmental parameters including soil and plant type, root distribution as well as nature and vertical distribution of the deposits. Long lasting availability of some radionuclides was shown to be the source of much higher transfer in forest ecosystems than in agricultural lands. This study aimed at reviewing the most relevant quantitative information on radionuclide transfers to forest biota including trees, understorey vegetation, mushrooms, berries and game animals. For both radiocaesium and radiostrontium in trees, the order of magnitude of mean Tag values was 10-3 m2 kg-1 (dry weight). Tree foliage was usually 2-12 times more contaminated than trunk wood. Maximum contamination of tree components with radiocaesium was associated with (semi-)hydromorphic areas with thick humus layers. The transfer of radionuclides to mushrooms and berries is high, in comparison with foodstuffs grown in agricultural systems. Concerning caesium uptake by mushrooms, the transfer is characterized by a very large variability of Tag, from 10-3 to 101 m2 kg-1 (dry weight). For berries, typical values are around 0.01-0.1 m2 kg-1 (dry weight). Transfer of radioactive caesium to game animals and reindeer and the rate of activity reduction, quantified as an ecological half-life, reflect the soil and pasture conditions at individual locations. Forests in temperate and boreal regions differ with respect to soil type and vegetation, and a faster decline of muscle activity concentrations in deer occurs in the temperate zone. However, in wild boar the caesium activity concentration shows no decline because of its special feeding habits. In the late phase, i.e. at least a few months since the external radionuclide contamination on feed plants has been removed, a Tag value of 0.01 m2 kg-1 (fresh weight) is common for 137Cs in the muscles of adult moose and terrestrial birds living in boreal forests, and 0.03 m2 kg-1 (fresh weight) for arctic hare. Radiocaesium concentrations in reindeer muscle in winter may exceed the summer content by a factor of more than two, the mean Tag values for winter ranging from 0.02 to 0.8 m2 kg-1 (fresh weight), and in summer from 0.04 to 0.4 m2 kg-1. The highest values are found in the year of initial contamination, followed by a gradual reduction. In waterfowl a relatively fast decline in uptake of 137Cs has been found, with Tag values changing from 0.01 to 0.002 m2 kg-1 (fresh weight) in the three years after the contaminating event, the rate being determined by the dynamics of 137Cs in aquatic ecosystems.

2009-09-01

88

Photosynthesis of temperate Eucalyptus globulus trees outside their native range has limited adjustment to elevated CO2 and climate warming.  

Science.gov (United States)

Eucalyptus species are grown widely outside of their native ranges in plantations on all vegetated continents of the world. We predicted that such a plantation species would show high potential for acclimation of photosynthetic traits across a wide range of growth conditions, including elevated [CO2] and climate warming. To test this prediction, we planted temperate Eucalyptus globulus Labill. seedlings in climate-controlled chambers in the field located >700 km closer to the equator than the nearest natural occurrence of this species. Trees were grown in a complete factorial combination of elevated CO2 concentration (eC; ambient [CO2] +240 ppm) and air warming treatments (eT; ambient +3 °C) for 15 months until they reached ca. 10 m height. There was little acclimation of photosynthetic capacity to eC and hence the CO2-induced photosynthetic enhancement was large (ca. 50%) in this treatment during summer. The warming treatment significantly increased rates of both carboxylation capacity (V(cmax)) and electron transport (Jmax) (measured at a common temperature of 25 °C) during winter, but decreased them significantly by 20-30% in summer. The photosynthetic CO2 compensation point in the absence of dark respiration (?*) was relatively less sensitive to temperature in this temperate eucalypt species than for warm-season tobacco. The temperature optima for photosynthesis and Jmax significantly changed by about 6 °C between winter and summer, but without further adjustment from early to late summer. These results suggest that there is an upper limit for the photosynthetic capacity of E. globulus ssp. globulus outside its native range to acclimate to growth temperatures above 25 °C. Limitations to temperature acclimation of photosynthesis in summer may be one factor that defines climate zones where E. globulus plantation productivity can be sustained under anticipated global environmental change. PMID:23824839

Crous, Kristine Y; Quentin, Audrey G; Lin, Yan-Shih; Medlyn, Belinda E; Williams, David G; Barton, Craig V M; Ellsworth, David S

2013-12-01

89

Spatial variation of biomass of seaweed assemblages in the temperate-tropical transition zone of Baja California Peninsula, Mexico / Variación espacial de la biomasa de macroalgas en una zona de transición templado-tropical en la Península de Baja California, México  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Se analizaron los cambios en la biomasa de las asociaciones de macroalgas en una zona de transición templado-tropical entre octubre de 1996 y agosto de 1997 en cuatro localidades. Las localidades con la temperatura más baja, alto índice de surgencias y mayor dominancia de sustrato duro presentaron l [...] os mayores valores de biomasa de macroalgas (El Cardoncito (7.2 kg m-2) y Las Boyitas (6.2 kg m-2)) y la mayor cantidad de especies de afinidad templada. Por el contrario El Datilito (0.366 kg m-2) en donde la temperatura fue más alta, no hay evidencia de surgencias, el sustrato es arenoso, es un área más somera y protegida, presentó el menor valor de biomasa de macroalgas y la menor proporción de algas de afinidad templada. Los análisis de componentes principales y similaridad mostraron una estrecha relación entre El Cardoncito y Las Boyitas. El Datilito se mantuvo como una localidad independiente, mientras que Chester Rock (4.3 kg m-2) tuvo características intermedias de biomasa de algas. La estrecha relación entre las dos primeras localidades puede explicarse por la similaridad en términos de su alta biomasa aunado con las características fisiográficas y ambientales que presentaron. El Datilito presentó características fisiográficas y ambientales muy diferentes a las demás localidades, además de tener muy poca biomasa de macroalgas. Abstract in english Biomass changes of seaweed assemblages in four locations in a temperate-tropical transition zone were analyzed between October 1996 and August 1997. Locations with lower temperature, a high index of upwelling, and high quantities of hard substrate presented the largest values of biomass of seaweed ( [...] El Cardoncito (7.2 kg m-2), and Las Boyitas (6.2 kg m-2)) and the biggest quantity of species of temperate affinity. Conversely, El Datilito (0.366 kg m-2), with a higher temperature, no evidence of upwelling, sandy substrate, and located in protected shallow waters, presented the lowest values of biomass and the lowest proportion of temperate affinity seaweed. The PCA and similarity analysis showed a close relationship between El Cardoncito and Las Boyitas. El Datilito was categorized as independent location, while Chester Rock (4.3 kg m-2) displayed intermediate characteristics. The close relationship observed between the first two locations can be explained by the similarity of their high biomass and physiographic and environmental characteristics. El Datilito has very different physiographic and environmental characteristics and a very low biomass.

Casas Valdez, Margarita; Aguila Ramírez, Ruth Noemí.

90

Spatial variation of biomass of seaweed assemblages in the temperate-tropical transition zone of Baja California Peninsula, Mexico Variación espacial de la biomasa de macroalgas en una zona de transición templado-tropical en la Península de Baja California, México  

Directory of Open Access Journals (Sweden)

Full Text Available Biomass changes of seaweed assemblages in four locations in a temperate-tropical transition zone were analyzed between October 1996 and August 1997. Locations with lower temperature, a high index of upwelling, and high quantities of hard substrate presented the largest values of biomass of seaweed (El Cardoncito (7.2 kg m-2, and Las Boyitas (6.2 kg m-2 and the biggest quantity of species of temperate affinity. Conversely, El Datilito (0.366 kg m-2, with a higher temperature, no evidence of upwelling, sandy substrate, and located in protected shallow waters, presented the lowest values of biomass and the lowest proportion of temperate affinity seaweed. The PCA and similarity analysis showed a close relationship between El Cardoncito and Las Boyitas. El Datilito was categorized as independent location, while Chester Rock (4.3 kg m-2 displayed intermediate characteristics. The close relationship observed between the first two locations can be explained by the similarity of their high biomass and physiographic and environmental characteristics. El Datilito has very different physiographic and environmental characteristics and a very low biomass.Se analizaron los cambios en la biomasa de las asociaciones de macroalgas en una zona de transición templado-tropical entre octubre de 1996 y agosto de 1997 en cuatro localidades. Las localidades con la temperatura más baja, alto índice de surgencias y mayor dominancia de sustrato duro presentaron los mayores valores de biomasa de macroalgas (El Cardoncito (7.2 kg m-2 y Las Boyitas (6.2 kg m-2 y la mayor cantidad de especies de afinidad templada. Por el contrario El Datilito (0.366 kg m-2 en donde la temperatura fue más alta, no hay evidencia de surgencias, el sustrato es arenoso, es un área más somera y protegida, presentó el menor valor de biomasa de macroalgas y la menor proporción de algas de afinidad templada. Los análisis de componentes principales y similaridad mostraron una estrecha relación entre El Cardoncito y Las Boyitas. El Datilito se mantuvo como una localidad independiente, mientras que Chester Rock (4.3 kg m-2 tuvo características intermedias de biomasa de algas. La estrecha relación entre las dos primeras localidades puede explicarse por la similaridad en términos de su alta biomasa aunado con las características fisiográficas y ambientales que presentaron. El Datilito presentó características fisiográficas y ambientales muy diferentes a las demás localidades, además de tener muy poca biomasa de macroalgas.

Margarita Casas Valdez

2008-08-01

91

Time-temperature equivalence in Martensite tempering  

Energy Technology Data Exchange (ETDEWEB)

The relationship between time and temperature is of great consequence in many materials-related processes including the tempering of martensite. In 1945, Hollomon and Jaffe quantified the 'degree of tempering' as a function of both tempering time, t, and tempering temperature, T, using the expression, T(log t + c). Here, c is thought to be a material constant and appears to decrease linearly with increasing carbon content. The Hollomon-Jaffe tempering parameter is frequently cited in the literature. This work reviews the original derivation of the tempering parameter concept, and presents the use of the characteristics diffusion distance as an alternative time-temperature relationship during martensite tempering. During the tempering of martensite, interstitial carbon atoms diffuse to form carbides. In addition, austenite decomposes, dislocations and grain boundaries rearrange, associated with iron self diffusion. Since these are all diffusional processes, it is reasonable to expect the degree of tempering to relate to the extent of diffusion.

Hachenberg, Robert, E. [Los Alamos National Laboratory; Thomas, Grant, A. [CSM; Speer, John, G. [CSM; Matlock, David, K. [CSM; Krauss, George [CSM

2008-01-01

92

Community Compensatory Trend Prevails from Tropical to Temperate Forest  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Community compensatory trend (CCT) is thought to facilitate persistence of rare species and thus stabilize species composition in tropical forests. However, whether CCT acts over broad geographical ranges is still in question. In this study, we tested for the presence of negative density dependence (NDD) and CCT in three forests along a tropical-temperate gradient. Inventory data were collected from forest communities located in three different latitudinal zones in China. Two widely used meth...

Xiao, Lin; Yu, Shixiao; Li, Mingguang; Wang, Yongfan

2012-01-01

93

Tempering effect on the properties of welded joints of 15Kh2NMFA  

International Nuclear Information System (INIS)

A study was made on the effect of post welding tempering on mechanical properties of the basic metal, weld and heat affected zone, their resistance to softening during the following technological heatings and to brittle failure, as well as on phase composition and the state of basic phase components of 15Kh2NMFA steel. It was shown that the optimal combination of strength and resistance to embrittlement of the basic metal and weld is reached at tempering temperature of 650 deg C

1982-10-01

94

Diversity and abundance of photosynthetic sponges in temperate Western Australia  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Photosynthetic sponges are important components of reef ecosystems around the world, but are poorly understood. It is often assumed that temperate regions have low diversity and abundance of photosynthetic sponges, but to date no studies have investigated this question. The aim of this study was to compare the percentages of photosynthetic sponges in temperate Western Australia (WA with previously published data on tropical regions, and to determine the abundance and diversity of these associations in a range of temperate environments. Results We sampled sponges on 5 m belt transects to determine the percentage of photosynthetic sponges and identified at least one representative of each group of symbionts using 16S rDNA sequencing together with microscopy techniques. Our results demonstrate that photosynthetic sponges are abundant in temperate WA, with an average of 63% of sponge individuals hosting high levels of photosynthetic symbionts and 11% with low to medium levels. These percentages of photosynthetic sponges are comparable to those found on tropical reefs and may have important implications for ecosystem function on temperate reefs in other areas of the world. A diverse range of symbionts sometimes occurred within a small geographic area, including the three "big" cyanobacterial clades, Oscillatoria spongeliae, "Candidatus Synechococcus spongiarum" and Synechocystis species, and it appears that these clades all occur in a wide range of sponges. Additionally, spongin-permeating red algae occurred in at least 7 sponge species. This study provides the first investigation of the molecular phylogeny of rhodophyte symbionts in sponges. Conclusion Photosynthetic sponges are abundant and diverse in temperate WA, with comparable percentages of photosynthetic to non-photosynthetic sponges to tropical zones. It appears that there are three common generalist clades of cyanobacterial symbionts of sponges which occur in a wide range of sponges in a wide range of environmental conditions.

Brümmer Franz

2009-02-01

95

Evaluation of tropically adapted straightbred and crossbred cattle: postweaning gain and feed efficiency when finished in a temperate climate.  

Science.gov (United States)

Beef cows in the subtropical USA must be adapted to the stressors of the environment, typically supplied by using Brahman (Br) breeding. Calves produced in the region, however, are usually grown and finished in more temperate regions, and have a perceived reputation for poor ADG and feed efficiency during finishing. Compromised fertility and carcass quality often associated with the Br have increased interest in tropically adapted Bos taurus breed types. The objective of this study was to evaluate 3 breeds [An = Angus (Bos taurus, temperate); Br (B. indicus, tropical); and Ro = Romosinuano (B. taurus, tropical)] and all possible crosses during various segments of post-weaning growth, and for feed efficiency during the finishing phase. Steer calves (n = 473) born over 3 yr were weaned in late September, backgrounded for at least 21 d (BKG), shipped 2,025 km to El Reno, OK, in October, fed a preconditioning diet for 28 d (RCV), grazed wheat (Triticum aestivum L.) pasture from November to May (WHT), finished on a conventional feedlot diet (FIN), and serially harvested after approximately 95, 125, and 150 d on feed. Body weight and ADG during each segment were tested using a mixed model that included calf age at weaning, year (Y), breed of sire (SB), breed of dam (DB), and interactions. In addition, winter treatment (continuous wheat or reduced grazing of wheat with supplement) was included for the wheat and feedlot phases. Sire within SB × SB [and pen (barn × year) for feedlot phase] were considered random. The SB × DB interaction was significant for all traits (P < 0.01) except exit velocity taken at weaning and ADG during FIN, but both traits were affected by 3-way interactions with Y or harvest group. Tropically-adapted purebred steers had greater (P < 0.01) ADG than AnAn through weaning and BKG in FL but the reverse was true during the RCV and WHT segments. Similar, but less pronounced results were noted for F(1) steers with 100% tropical influence compared with those with only 50%. Heterosis was numerically greater for most traits for An × Br (11 to 64%) compared with An × Ro and Br × Ro (3 to 42%), which were similar. In a subset of the steers (n = 261), G:F was not influenced by level of tropical breeding, but tropically adapted steers were more efficient (P < 0.05) by residual feed intake. No heterosis was evident. These data show that in temperate zones, winter is the period when productivity of tropically adapted cattle is compromised. PMID:22247114

Coleman, S W; Chase, C C; Phillips, W A; Riley, D G; Olson, T A

2012-06-01

96

New Pest Response Guidelines: Temperate Terrestrial Gastropods.  

Science.gov (United States)

Use New Pest Response Guidelines: Temperate Terrestrial Gastropods as a guide when designing a program to detect, monitor, control, contain, or eradicate an infestation of temperate climate pest snails and slugs in the United States and collaborating terr...

2008-01-01

97

Responses of plankton and fish from temperate zones to UVR and temperature in a context of global change / Respuestas del plancton y peces de zonas templadas a la RUV y la temperatura en un contexto de cambio global  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: English Abstract in spanish En las últimas décadas, tanto la temperatura como la radiación UVB (280-315 nm) en la superficie del planeta han aumentado a velocidades crecientes como resultado de las actividades humanas. Muchos estudios han evaluado ya los efectos de la temperatura en ecosistemas acuáticos, pero ahora el campo d [...] e estudio se amplía a medida que cobra importancia la combinación de dichos factores. En el presente estudio, intentamos rever una parte de lo que sabemos acerca de los efectos de la RUV y la temperatura en el plancton marino y dulceacuícola y peces de latitudes medias (definidas como aquellas comprendidas entre 30 y 60º), especialmente en la región Patagónica, debido a las características particulares de estas regiones. La RUV afecta (en general, negativamente) casi todos los procesos, desde la fijación de carbono hasta el comportamiento y ciertamente todos los niveles tróficos dentro del plancton, desde virus hasta larvas de peces. El mayor efecto negativo de la RUV es probablemente la acción mutagénica de la UVB, la cual afecta un número de procesos tales como fotosíntesis, crecimiento y división celular, entre muchos otros. En los metazoos, la RUV puede ser un factor de estrés que afecta la supervivencia, o bien puede mostrar efectos subletales tales como en el comportamiento y alimentación. Es difícil extraer un patrón general en cuanto a las respuestas, aun dentro de un grupo de organismos, ya que éstas son generalmente especie-específicas y están fuertemente influenciadas por condiciones locales (e.g., penetración de la RUV, relación PAR/RUV y aclimatación). A pesar de que en muchos casos se han determinado efectos significativos, muchos organismos también disponen de mecanismos para evitar o minimizar el daño producido por la RUV. Sin embargo, este puede no ser el caso si consideramos los cambios en la temperatura. En peces por ejemplo, la temperatura es probablemente el factor más importante que determina la distribución del hábitat, y por lo tanto la biogeografía debe ser considerada para considerar las posibles consecuencias de los cambios de temperatura y de la RUV. Aun en los diferentes escenarios predichos por los modelos climáticos (incluyendo la recuperación de la capa de ozono y el aumento de la temperatura durante las próximas décadas) serán necesarias más investigaciones combinando RUV y temperatura para entender las respuestas de los ecosistemas acuáticos en el contexto del cambio global. Abstract in english In the last decades, both temperature and UVB (280-315 nm) radiation on the surface of the Earth increased at growing rates as a result of human activities. Many studies had evaluated the effects of temperature on aquatic ecosystems, but now the field broadens as the combination and variations of te [...] mperature and radiation gains especial importance. In this work we attempt to revisit some of our knowledge about the effects of UVR and temperature on marine and freshwater plankton and fish from temperate regions (defined here as latitudes between 30-60º), especially from the Patagonia area, due to the special characteristics found in these sites. UVR affects (often negatively) almost all processes, from carbon fixation to behavior; and certainly all trophic levels in plankton, from virus to fish larvae. The most prominent UVR danger is probably the mutagenic action of UVB, which will affect a number of processes such as photosynthesis, growth and cell division, among many others. In metazoans, UVR may cause stress upon survival or show sublethal effects such as those in behavior and feeding. It is difficult to extract a general pattern, even in a group of organisms, as responses to UVR appear to be species-specific and strongly influenced by local conditions (e.g., UVR penetration, PAR/UVR ratios, and acclimation). While in many cases significant effects have been determined, a number of mechanisms are available to avoid and / or minimize the damage produced by UVR. However,

Rodrigo J, Gonçalves; María Sol, Souza; Juana, Aigo; Beatriz, Modenutti; Esteban, Balseiro; Virginia E, Villafañe; Víctor, Cussac; E Walter, Helbling.

98

Intraspecific Variation in Leaf Life Span for the Semi-evergreen Liana Akebia trifoliata is Caused by Both Seasonal and Aseasonal Factors in a Temperate Forest  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperateforest in Japan. Akebia is semi-evergreen: some leaves are shed before winter, while others remain through thewinter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variationin the timing of leaf emergence. Leaves that appeared just before winter over-wintered, while leaves appearingearlier were shed. However, it is unclear whether leaves of the sam...

2008-01-01

99

Winter Weather Emergencies  

Science.gov (United States)

Severe winter weather can lead to health and safety challenges. You may have to cope with Cold related health ... Although there are no guarantees of safety during winter weather emergencies, you can take actions to protect ...

100

Concussion in Winter Sports  

Science.gov (United States)

... en... Favorites Delicious Digg Google Bookmarks Concussion in Winter Sports Get prepared for concussions on and off ... and keep an action plan on hand. Each winter, hundreds of thousands of young athletes head out ...

 
 
 
 
101

Science of Winter  

Science.gov (United States)

Science of Winter is a collection of activities, lessons, interactives, images, or other content illustrating or demonstrating scientific aspects of winter weather, conditions, processes, or phenomena, appropriate for middle school, informal education, and general audiences.

2009-07-30

102

Transformation and tempering behavior of 12Cr-1Mo-0.3V martensitic stainless steel weldments  

International Nuclear Information System (INIS)

Autogeneous, bead-on-plate gas tungsten-arc (GTA) and laser welds in a 12Cr-1Mo-0.3V (HT9) martensitic stainless steel were evaluated using both optical metallography and microhardness techniques. The as-welded fusion zone microstructures consisted of a mixture of untempered martensite and metastable delta ferrite and exhibited a hardness in the range of Rsub(c) 48-55. Four distinct microstructural regions were identified in the heat-affected zone (HAZ) of the GTA welds and could be related to specific phase regions on the equilibrium phase diagram. The tempering behavior of the GTA and laser welds was similar. The tempering response was relatively sluggish at temperatures below 6000C (11100F). Tempering for 1 hour at 8000C (14700F) reduced the hardness of both the fusion zone and HAZ to the level of the quenched and tempered base metal. (orig.)

1982-03-01

103

Transformation and tempering behavior of 12Cr-1Mo-0.3V martensitic stainless steel weldments  

Science.gov (United States)

Autogenous, bead-on-plate gas tungsten-arc (GTA) and laser welds in a 12Cr-1Mo-0.3V (HT9) martensitic stainless steel were evaluated using both optical metallography and microhardness techniques. The as-welded fusion zone microstructures consisted of a mixture of untempered martensite and metastable delta ferrite and exhibited a hardness in the range of R c 48-55. Four distinct microstruetural regions were identified in the heat-affected zone (HAZ) of the GTA welds and could be related to specific phase regions on the equilibrium phase diagram. The tempering behavior of the GTA and laser welds was similar. The tempering response was relatively sluggish at temperatures below 600°C (1110°F). Tempering for 1 hour at 800°C (1470°F) reduced the hardness of both the fusion zone and HAZ to the level of the quenched and tempered base metal.

Lippold, John C.

104

Quantity component of the effectiveness of seed dispersal by birds in the temperate rainforest of Chiloé, Chile Componente cuantitativo de la efectividad de dispersión de semillas por aves en el bosque templado de Chiloé, Chile  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The quantity component of the disperser effectiveness of resident birds during the autumn-winter period has not yet been detailed in temperate rainforests of South America. In this study, the potentially frugivorous bird species in the temperate rainforests of southern Chile during the Austral autumn-winter were identified, and the quantity component of the disperser effectiveness of the birds (number of visits and number of seeds dispersed per hour) were evaluated for the tree species Luma a...

Miguel Salvande; Figueroa, Javier A.; Armesto, Juan J.

2011-01-01

105

Citril finches during the winter: patterns of distribution, the role of pines and implications for the conservation of the species.  

Directory of Open Access Journals (Sweden)

Full Text Available The Citril finch Serinus citrinella is a Paleartic endemic species that breeds in the subalpine mountain zones of western temperate Europe. The species seems to be suffering a serious decline in its northern range, mainly in the Black Forest and the NE of the Alps. Numerous reasons have been provided for this decline, but all of them have been related to breeding habitats. Given that the species undergoes an altitu¬dinal migration and that during winter it may use very different habitats, a sound knowledge of the distribution patterns and habitats used outside the breeding period is needed to conduct adequate conservation policies and management. This information, however, is largely lacking. The aim of this paper was to determine the current habitat used by Citril finches in north–eastern Spain during the winter, to analyse habitat suitability and to study movements, by investigating the origin of birds that overwinter in Catalonia. Citril finch distribution was modelled using both discriminant analysis and maximum entropy modelling, on the basis of species occurrences during winter in Catalonia (data from 1972–2009. Results showed that the presence of two tree species, Black pine (Pinus nigra subsp. salzmanii and Scots pine (Pinus sylvestris, both as part of mixed open forests, and the presence of abundant farmland and arvensic plants —the two vegetation units located in a typical sub¬mediterranean context, where the warm temperatures (sunny days in late winter permit the cones to open—, were the ecological and bioclimatic variables that explain the distribution model. All these variables in tandem seem to be the key for the current potential distribution of the Citril finch in winter (AUCscores: training data AUC= 0.955; test data AUC = 0.953. We analyzed recoveries (N = 238 of 2,368birds ringed at wintering grounds and 12,648 birds ringed at subalpine localities in the adjacent Pyrenees from 1977–2004. We found that in the study area, we recovered ringed birds from many different locations from across the distributional range of the species, including trans–Pyrenean birds from the Alps. This stresses the high mobility of Citril finch populations to reach wintering areas. From a conservation point of view, the high importance of pines (mainly Black pine for the wintering distribution of the species stresses that any threat on pines, especially forest fires, will have acute detrimental effects for Citril finch populations.

X. Colomé

2010-01-01

106

Protective coating of austenitic steel using robotized GMAW temper-bead technique; Rechargement d'inox austenitique en MAG temperbead robotise  

Energy Technology Data Exchange (ETDEWEB)

This paper summarises experimental results obtained in a study of GMAW temper-bead on low alloyed steel with austenitic consumables. Temper-bead on low alloyed steel with austenitic consumables is mainly used for repairing operations of heavy components such as vessel reactor of nuclear power plants. Experimental work aims at showing the performance of GMAW compared to GTAW and the consequences of GMAW temper-bead on 2OMND5 heat affected zones. (authors)

Carpreau, J.M. [Electricite de France (EDF/R and D), Recherche et Developpement, 92 - Chatou (France); Dainelli, P. [Institut de Soudure, 57 - Yutz (France)

2009-07-15

107

Winter World Explorations  

Science.gov (United States)

Cold winter weather can cause us to retreat into our indoor shells biding our time until the warmer days return. However, there is much to explore outside during the wintertime and the following sites share some important reasons and cautionary tips for Winter World Explorations. The first website, Princeton University's Outdoor Action Guide to Winter Camping by Rick Curtis, provides a thorough overview of Winter Camping including sections on Winter Travel, Snowshoeing Basics, Winter Water, and more. This site also provides links to OA Guides for Winter Shelters, and Hypothermia and Cold Injuries (1). The second site, from the Search and Rescue Society of British Columbia deals specifically with Hypothermia including useful information on Physiology, Signs, Symptoms, and Treatment Considerations (2). The third website, SnowSchool, is an innovative educational field program designed for 4th and 5th graders where "kids venture out into America's winter wildlands to discover all the living creatures under the snow." SnowSchool is a program of Winter Wildlands Alliance and "the nation's largest on-snow winter ecology education program" with 27 sites across the United States (3). The fourth website from the Minnesota DNR is a feature on Winter Bird Feeding which includes specific information about Winter Foods, Seeds and Mixes, Suet, Feeders, and Winter Feeder Layout (4). The fifth website, The Native Conifers of North America, is an excellent and very comprehensive online introduction and field guide to conifer species native to North America. The site includes A Key to the Genera and Species, sections on Selected Conifers from Different Parts of North America, and many beautiful photographs and line drawings (5). The sixth website (6) hosts an article on Winter Nutrition: Tips for people who exercise in the cold by nutrition counselor Nancy Clark, MS, RD. In her article, Ms. Clark answers common winter exercise questions like Why do I shiver when I get cold?, and Why do I feel hungrier in the winter than in the summer? Speaking of being hungrier in the winter, the final two websites offer recipes for winter stews and soups, a perfect way to end a day of winter exploring. One website offers a Hearty Winter Stew recipe from the University of Michigan Health System-Nutrition Services (7}. The other website, from The Ohio State University Extension -- Family Nutrition Program Newsletter tells us that January is National Soup Month, and offers recipes for stews, soups, and even instructions for bread soup bowls (8).

108

Ice-dependent winter survival of juvenile Atlantic salmon  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Changes in snow and ice conditions are some of the most distinctive impacts of global warming in cold temperate and Arctic regions, altering the environment during a critical period for survival for most animals. Laboratories studies have suggested that reduced ice cover may reduce the survival of stream dwelling fishes in Northern environments. This, however, has not been empirically investigated in natural populations in large rivers. Here, we examine how the winter survival of juvenile Atl...

Hedger, R. D.; Næsje, T. F.; Fiske, P.; Ugedal, O.; Finstad, A. G.; Thorstad, E. B.

2013-01-01

109

The well-tempered neutralino  

International Nuclear Information System (INIS)

The dark-matter prediction is usually considered as one of the successes of low-energy supersymmetry. We argue that, after LEP constraints are taken into account, the correct prediction for the dark-matter density, at a quantitative level, is no longer a natural consequence of supersymmetry, but it requires special relations among parameters, highly sensitive to small variations. This is analogous to the problem of electroweak-symmetry breaking, where the correct value of the Z mass is obtained only with a certain degree of fine tuning. In the general parameter space of low-energy supersymmetry, one of the most plausible solution to reproduce the correct value of the dark-matter density is the well-tempered neutralino, which corresponds to the boundary between a pure bino and a pure higgsino or wino. We study the properties of well-tempered neutralinos and we propose a simple limit of split supersymmetry that realizes this situation

2006-05-01

110

Winters fuels report  

Energy Technology Data Exchange (ETDEWEB)

The outlook for distillate fuel oil this winter is for increased demand and a return to normal inventory patterns, assuming a resumption of normal, cooler weather than last winter. With industrial production expected to grow slightly from last winter`s pace, overall consumption is projected to increase 3 percent from last winter, to 3.4 million barrels per day during the heating season (October 1, 1995-March 31, 1996). Much of the supply win come from stock drawdowns and refinery production. Estimates for the winter are from the Energy Information Administration`s (EIA) 4th Quarter 1995 Short-Tenn Energy Outlook (STEO) Mid-World Oil Price Case forecast. Inventories in place on September 30, 1995, of 132 million barrels were 9 percent below the unusually high year-earlier level. Inventories of high-sulfur distillate fuel oil, the principal type used for heating, were 13 percent lower than a year earlier. Supply problems are not anticipated because refinery production and the ready availability of imports should be adequate to meet demand. Residential heating off prices are expected to be somewhat higher than last winter`s, as the effects of lower crude oil prices are offset by lower distillate inventories. Heating oil is forecast to average $0.92 per gallon, the highest price since the winter of 1992-93. Diesel fuel (including tax) is predicted to be slightly higher than last year at $1.13 per gallon. This article focuses on the winter assessment for distillate fuel oil, how well last year`s STEO winter outlook compared to actual events, and expectations for the coming winter. Additional analyses include regional low-sulfur and high-sulfur distillate supply, demand, and prices, and recent trends in distillate fuel oil inventories.

NONE

1995-10-27

111

A case of congenital plasmodium vivax malaria from a temperate region in central china  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In February 2011, a rare case of congenital Plasmodium vivax malaria was diagnosed in a temperate region of Central China. An infant developed intermittent fever 20?days after delivery. Since this occurred during the non-transmission winter season in a low malaria endemic region and the infant’s mother did not have a clear malaria history or showed malaria symptoms at the time of the delivery, malaria infection was not suspected at the beginning. Later, on suspicion of potential malignant...

Liu, Xue; Tao, Zhi-yong; Fang, Qiang; Wang, Xue-mei; Zhang, Hui; Stoute, Jose A.; Xia, Hui; Cui, Liwang

2012-01-01

112

Preliminary Studies on Plants with Anthelmintic Properties in Kashmir—The North-West Temperate Himalayan Region of India  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is a growing interest in traditional uses of plants for health care among different communities especially in the developing countries. Kashmir valley is a temperate agro-climatic zone of north-west temperate Himalayan region of India and is blessed with a diverse variety of medicinal flora. The traditional uses of plants against parasitic infections in human beings and their live-stock is a common practice in the valley as most of the populations are rural and conventional veterinary d...

2012-01-01

113

Nuclear winter down under  

International Nuclear Information System (INIS)

The radiation that nuclear explosions produce and the subsequent fall-out play a relatively small part in the causes and consequences of a nuclear winter. More important are the injection of smoke and dust into the upper atmosphere and the subsequent effects on climate and agricultural productivity. The implications of nuclear winter for the Southern Hemisphere and Australia in particular, are examined

1986-01-01

114

Winter Art Education Project  

Science.gov (United States)

The purpose of this article is to describe how the Department of Art Education at the University of Lapland in Finland has developed winter art as a method of environmental and community-based art education. I will focus on the Snow Show Winter Art Education Project, a training project funded by the European Union and the State Provincial Office…

Jokela, Timo

2007-01-01

115

Laser beam welding tempered 300M ultrahigh mechanical strength steel  

Directory of Open Access Journals (Sweden)

Full Text Available AISI 300M ultrahigh strength steel has been used in a number of high demanding applications, such as the VLS Brazilian rocket project. This work intends to propose laser beam welding, with subsequent tempering, as a possible route for the fabrication of engineering pieces of this steel. A 2 kW fiber laser was used to produce welded coupons for metallographic, hardness and tensile strength tests. It has been shown that convenient laser parameters for a 3 mm thick plate are 50 mm/s welding speed and 1200 W laser power. However, both welded materials and heat-affected zones presented high hardness and negligible plastic deformation. In order to produce useful engineering parts, it was suggested a tempering treatment for 2 hours at temperatures of 200 or 400ºC. Tensile mechanical testing has shown that welded and tempered coupons presented both yield and maximum strengths comparable to the unwelded material. On the other hand, a maximum elongation of about 4% was obtained, in comparison with 12% from the bulk sample.

Sheila Medeiros de Carvalho

2012-03-01

116

Vibration failures in tempered steels  

International Nuclear Information System (INIS)

Comparative measurements of crack propagation in air on three types of tempered steel, ferrite, austenite and an aluminium alloy are described. A clear connection between the crack propagation and the stress ratio cannot be ascertained. Crack arrest occurs when the threshold value of the stress intensity ? K0, determined in tests using a constant range of the crack opening displacement, is reached. The number of striations counted on the cracked surface by microfractographical means was always less than the sum of the stress cycles applied. An accurate conclusion from the striation structure on the history of the fracture is only possible in certain materials under favourable conditions. (orig.)

1975-11-21

117

Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions). One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam), the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland). The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sedimen...

2005-01-01

118

Parallel tempering for the traveling salesman problem  

Energy Technology Data Exchange (ETDEWEB)

We explore the potential of parallel tempering as a combinatorial optimization method, applying it to the traveling salesman problem. We compare simulation results of parallel tempering with a benchmark implementation of simulated annealing, and study how different choices of parameters affect the relative performance of the two methods. We find that a straightforward implementation of parallel tempering can outperform simulated annealing in several crucial respects. When parameters are chosen appropriately, both methods yield close approximation to the actual minimum distance for an instance with 200 nodes. However, parallel tempering yields more consistently accurate results when a series of independent simulations are performed. Our results suggest that parallel tempering might offer a simple but powerful alternative to simulated annealing for combinatorial optimization problems.

Percus, Allon [Los Alamos National Laboratory; Wang, Richard [UCLA MATH DEPT; Hyman, Jeffrey [UCLA MATH DEPT; Caflisch, Russel [UCLA MATH DEPT

2008-01-01

119

Winter Storm Activity  

Science.gov (United States)

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Weather affects our everyday lives. Some days it's sunny and some days its not. The years weather is split up into seasons. 1. What are the four seasons? 2. What kind of weather do you see in the summer? 3. What kind of weather is unique to winter? 4. What ...

Haight, Jennifer

2010-02-22

120

Tempered relaxation with clustering patterns  

Energy Technology Data Exchange (ETDEWEB)

This work is motivated by the relaxation data for materials which exhibit a change of the relationship between the fractional power-law exponents when different relaxation peaks in their dielectric susceptibility are observed. Within the proposed framework we derive a frequency-domain relaxation function fitting the whole range of the two-power-law dielectric spectroscopy data with independent low- and high-frequency fractional exponents ? and ??, respectively. We show that this effect results from a contribution of different processes. For high frequencies it is determined by random stops and movement of relaxing components, and the low-frequency slope is caused by clustering in their temporal changes. -- Highlights: ? Further development in the theory of tempered relaxation. ? Based on the subordination of random processes with finite moments. ? Derived the relaxation function fitting the whole range of two-power-law data. ? Independence of low- and high-frequency fractional exponents in susceptibility.

Stanislavsky, Aleksander, E-mail: alexstan@ri.kharkov.ua [Institute of Radio Astronomy, Ukrainian National Academy of Sciences, 4 Chervonopraporna St., 61002 Kharkov (Ukraine); Weron, Karina, E-mail: Karina.Weron@pwr.wroc.pl [Institute of Physics, Wroc?aw University of Technology, Wybrze?e Wyspia?skiego 27, 50-370 Wroc?aw (Poland)

2011-11-21

 
 
 
 
121

Developing tempering parameter for ductile cast iron  

International Nuclear Information System (INIS)

In ductile cast iron (also known as nodular iron or spheroidal graphite cast irons), the graphite is present in tiny spheres or nodules. These ductile cast irons are stronger and has higher elongation than the grey iron or malleable iron, thus have found a wide range of industrial and structural applications. The heat treatment of ductile iron castings produces a significant different properties in mechanical properties from as cast ductile iron. Heat treatment procedures, such as stress relieving, annealing normalizing, quenching and tempering, austempering and surface hardening are the most common for the modification of mechanical properties of ductile irons. Tempered hardness depends upon its as quenched hardness level, alloy contents, tempering temperature and time. The focus of this paper is the quantitative aspects of quenching and tempering, and explaining a strategy to develop a master curve to correlate time, tempering temperature and hardness. This master curve is based upon defining a tempering parameters, which is similar in mathematical structure to the Larson-Miller Parameter in creep. Such a parameter has been successfully used in defining the tempering response of a variaety of steels, and have been found to be applicable also in the cse of cast iron. (author) 6 figs

1995-01-01

122

Environmental predictors of seasonal influenza epidemics across temperate and tropical climates.  

Science.gov (United States)

Human influenza infections exhibit a strong seasonal cycle in temperate regions. Recent laboratory and epidemiological evidence suggests that low specific humidity conditions facilitate the airborne survival and transmission of the influenza virus in temperate regions, resulting in annual winter epidemics. However, this relationship is unlikely to account for the epidemiology of influenza in tropical and subtropical regions where epidemics often occur during the rainy season or transmit year-round without a well-defined season. We assessed the role of specific humidity and other local climatic variables on influenza virus seasonality by modeling epidemiological and climatic information from 78 study sites sampled globally. We substantiated that there are two types of environmental conditions associated with seasonal influenza epidemics: "cold-dry" and "humid-rainy". For sites where monthly average specific humidity or temperature decreases below thresholds of approximately 11-12 g/kg and 18-21°C during the year, influenza activity peaks during the cold-dry season (i.e., winter) when specific humidity and temperature are at minimal levels. For sites where specific humidity and temperature do not decrease below these thresholds, seasonal influenza activity is more likely to peak in months when average precipitation totals are maximal and greater than 150 mm per month. These findings provide a simple climate-based model rooted in empirical data that accounts for the diversity of seasonal influenza patterns observed across temperate, subtropical and tropical climates. PMID:23505366

Tamerius, James D; Shaman, Jeffrey; Alonso, Wladimir J; Alonso, Wladmir J; Bloom-Feshbach, Kimberly; Uejio, Christopher K; Comrie, Andrew; Viboud, Cécile

2013-03-01

123

Mapping Forest Fire Susceptibility in Temperate Mountain Areas with Expert Knowledge. A Case Study from Iezer Mountains, Romanian Carpathians  

Science.gov (United States)

Forest fires in Romanian Carpathians became a frequent phenomenon during the last decade, although local climate and other environmental features did not create typical conditions. From 2004, forest fires affect in Romania more than 100 hectares/year of different forest types (deciduous and coniferous). Their magnitude and frequency are not known, since a historical forest fire inventory does not exist (only press papers and local witness for some selected events). Forest fires features the summer dry periods but there are dry autumns and early winter periods with events of different magnitudes. The application we propose is based on an empirical modeling of forest fire susceptibility in a typical mountain area from the Southern Carpathians, the Iezer Mountains (2462 m). The study area features almost all the altitudinal vegetation zones of the European temperate mountains, from the beech zone, to the coniferous zone, the subalpine and the alpine zones (Mihai et al., 2007). The analysis combines GIS and remote sensing models (Chuvieco et al., 2012), starting from the ideas that forest fires are featured by the ignition zones and then by the fire propagation zones. The first data layer (ignition zones) is the result of the crossing between the ignition factors: lightning - points of multitemporal occurence and anthropogenic activities (grazing, tourism and traffic) and the ignition zones (forest fuel zonation - forest stands, soil cover and topoclimatic factor zonation). This data is modelled from different sources: the MODIS imagery fire product (Hantson et al., 2012), detailed topographic maps, multitemporal orthophotos at 0.5 m resolution, Landsat multispectral imagery, forestry cadastre maps, detailed soil maps, meteorological data (the WorldClim digital database) as well as the field survey (mapping using GPS and local observation). The second data layer (fire propagation zones) is the result of the crossing between the forest fuel zonation, obtained with the help of forestry data, the wind regime data and the topographic features of the mountain area (elevation, slope declivity, slope aspect). The analysis also consider the insolation degree of mountain slopes, that creates favourable conditions for fire propagation between different canopies. These data layers are integrated within a simple GIS analysis in order to intersect the ignition zones with the fire propagation zones in order to obtain the potential areas to be affected by fire. The digital map show three levels of forest fire susceptibility, differenced on the basis of expert knowledge. The map can be validated from the statistical point of view with the polygons of the forest fire affected areas mapped from Landsat TM, ETM+ and OLI satellite imagery. The mapping results could be integrated within the forest management strategies and especially within the forest cadastre and development maps (updated every ten years). The result can confirm that the data gap in terms of forest fire events can be filled with expert knowledge. References Chuvieco, E, Aguado, I., Jurdao, S., Pettinari, M., Yebra, M., Salas, J., Hantson, S., de la Riva, J., Ibarra, P., Rodrigues, M., Echeverria, M., Azqueta, D., Roman, M., Bastarrika, A., Martinez, S., Recondo, C., Zapico, E., Martinez-Vega F.J. (2012) Integrating geospatial information into fire risk assessment, International Journal of Wildland Fire, 2,2, 69-86. Hantson, S., Padilla, M., Corti., D, Chuvieco, E. (2013) Strenghts and weaknesses of MODIS hotspots to characterize Global fire occurence, Remote Sensing of Environment, 131, 1, 152-159. Mihai, B., Savulescu, I.,Sandric, I. (2007) Change detection analysis (1986/2002) for the alpine, subalpine and forest landscape in Iezer Mountains (Southern Carpathians, Romania), Mountain Research and Development, 27, 250-258.

Mihai, Bogdan; Savulescu, Ionut

2014-05-01

124

The embryonic shoot: a lifeline through winter.  

Science.gov (United States)

The tiny vascular axis of the embryo emerges post-embryonically as an elaborate and critical infrastructure, pervading the entire plant system. Its expansive nature is especially impressive in trees, where growth and development continue for extended periods. While the shoot apical meristem (SAM) orchestrates primary morphogenesis, the vascular system is mapped out in its wake in the provascular cylinder, situated just below the emerging leaf primordia and surrounding the rib meristem. Formation of leaf primordia and provascular tissues is incompatible with the harsh conditions of winter. Deciduous trees of boreal and temperate climates therefore enter a survival mode at the end of the season. However, to be competitive, they need to maximize their growth period while avoiding cellular frost damage. Trees achieve this by monitoring photoperiod, and by timely implementation of a survival strategy that schedules downstream events, including growth cessation, terminal bud formation, dormancy assumption, acquisition of freezing tolerance, and shedding of leaves. Of central importance are buds, which contain an embryonic shoot that allows shoot development and elongation in spring. The genetic and molecular processes that drive the cycle in synchrony with the seasons are largely elusive. Here, we review what is known about the signals and signal conduits that are involved, the processes that are initiated, and the developmental transitions that ensue in a terminal bud. We propose that addressing dormancy as a property of the SAM and the bud as a unique shoot type will facilitate our understanding of winter dormancy. PMID:24368502

van der Schoot, Christiaan; Paul, Laju K; Rinne, Päivi L H

2014-04-01

125

Appropriate welding conditions of temper bead weld repair for SQV2A pressure vessel steel  

Energy Technology Data Exchange (ETDEWEB)

Temper bead welding technique is one of the most important repair welding methods for large structures for which it is difficult to perform the specified post weld heat treatment. In this study, appropriate temper bead welding conditions to improve the characteristics of heat affected zone (HAZ) are studied using pressure vessel steel SQV2A corresponding to ASTM A533 Type B Class 1. Thermal/mechanical simulator is employed to give specimens welding thermal cycles from single to quadruple cycle. Charpy absorbed energy and hardness of simulated CGHAZ by first cycle were degraded as compared with base metal. Improvability of these degradations by subsequent cycles is discussed and appropriate temper bead thermal cycles are clarified. When the peak temperature lower than Ac1 and near Ac1 in the second thermal cycle is applied to CGAHZ by first thermal cycle, the characteristics of CGHAZ improve enough. When the other peak temperatures (that is, higher than Ac1) in the second thermal cycle are applied to the CGHAZ, third or more thermal cycle temper bead process should be applied to improve the properties. Appropriate weld condition ranges are selected based on the above results. The validity of the selected ranges is verified by the temper bead welding test. (orig.)

Mizuno, R.; Matsuda, F. [NDE Center, Japan Power Engineering and Inspection Corp. (Japan); Brziak, P. [Welding Research Inst. - Industrial Inst. of Slovak Republic (Slovakia); Lomozik, M. [Inst. of Welding (Poland)

2004-07-01

126

The nuclear winter  

International Nuclear Information System (INIS)

Nuclear winter is an example of possible secondary effects, and if we speak of secondary we are thinking of small-scale second-order effects, but a nuclear winter is not a second-order effect. If you calculate the amount of heat produced by a nuclear explosion, it is a very small amount which does not have any chance of changing the Earth's climate, but a nuclear explosion drives or stars some new mechanism - the mechanism of nuclear winter - after 100 megatons of dust are transferred to the upper atmosphere. Another example of such amplification is radioactive fall-out, especially long-life radioactive fall-out after the possible elimination of the nuclear power industry, nuclear storage and distribution of storage waste around the globe. This is a very powerful amplification mechanism

1986-01-01

127

Winter Storm Lesson Plan  

Science.gov (United States)

The subject of this lesson is Winter Storms. The length will be approximately 55 minutes (~15 minutes for each of the three websites and ~10 minutes for the students to create their slideshows). The slideshows may be presented the following day if not enough time is available. This lesson is intended for 4th grade and is directed towards Standard 2 of the 4th grade science core curriculum. This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Winter Storms Connection to Standards: Utah Core Curriculum: Science Standard 2 (Students will understand that the elements of weather can be observed, measured, and recorded to make predictions and determine simple weather patterns.) NETS-T: 1. Facilitate and Inspire Student Learning and Creativity - Students will be using websites and situations that ...

S., Tasia

2010-09-23

128

Tempered automorphic representations of the unitary group  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Following Arthur's study of the representations of the orthogonal and symplectic groups, we prove many cases of both the local and global Arthur conjectures for tempered representations of the unitary group. This completes the proof of Arthur's description of the discrete series representations of the quasi-split $p$-adic unitary group, and Arthur's description of the tempered discrete automorphic representations of the unitary group, satisfying certain technical conditions.

White, Paul-james

2011-01-01

129

Summable families in tempered distribution spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this note we define summable families in tempered distribution spaces and we state some their properties and characterizations. Summable families are the analogous of summable sequences in separable Hilbert spaces, but in tempered distribution spaces, having elements (functional) realizable as generalized vectors indexed by real Euclidean spaces (not pointwise defined ordered families of scalars indexed by real Euclidean spaces in the sense of distributions). Any family w...

Carfi?, David

2011-01-01

130

Winter Storm (weather)  

Science.gov (United States)

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. First think about these questions: 1. What is your favorite aspect of winter weather? 2. How does the weather effect your everyday life? Form groups of THREE. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper... 1. In general, when are winds formed? 2. When winds are blowing, how can you ...

Miller, Aubree

2009-09-28

131

Tempering resistance of martensite strain hardening  

International Nuclear Information System (INIS)

The volumetric, the resistometric, X-ray and internal friction methods are employed to investigate the mechanical and the physical properties of 28Kh3SNMVFA steel in heating after deformation from 0 to 20 % in martensitic state (hardening and tempering at 200 deg C), and the effect is determined of the subsequent tempering at 200-600 deg C. It has been shown that the strength of the deformed steel after deformation and tempering at temperatures of 500 deg C and over is higher than that of a non-deformed one. This difference is the greater, the higher the degree of deformation. A special carbide M7C3 has been found after tempering at 500-550 deg C in a steel deformed by 20%. No special carbides have been detected at lesser degrees of deformation. The best complex of mechanical properties of 28Kh3SNMVFA steel is obtained after the following treatment: hardening, tempering at 200 deg C, rolling with a 20% degree of deformation, tempering at 200 deg C. The strength of the deformed steel in short-time tests at elevated temperatures (up to 500 deg C) is found to be higher than that of the hardened steel

1978-01-01

132

Acoplamiento pelágico-bentónico: respuesta de la zona bentónica profunda a la sedimentación del florecimiento invernal de diatomeas en el lago oligotrófico Alchichica, Puebla, México / Pelagic-benthic coupling: deep benthic zone response to winter diatom bloom sinking in oligotrophic Lake Alchichica, Puebla, Mexico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish El objetivo del presente estudio es reconocer la existencia de un acoplamiento pelágico-bentónico en el lago oligotrófico tropical Alchichica evaluando la respuesta de la zona bentónica profunda a la sedimentación del florecimiento invernal de diatomeas. Se midió la biomasa fitoplanctónica en la col [...] umna de agua a lo largo de un ciclo anual, al igual que la concentración de clorofila a sedimentaria. Alchichica es un lago monomíctico cálido con un periodo de circulación invernal y estratificación el resto del año. La presencia de turbulencia y nutrimentos durante el periodo de circulación favorecen el desarrollo de un florecimiento de diatomeas compuesto por especies de talla grande (p. e., Cyclotella alchichicana), las cuales se sedimentan al no ser consumidas en su totalidad. La zona bentónica profunda del lago responde a la sedimentación del florecimiento invernal de diatomeas con el desarrollo y permanencia por un periodo prolongado de anoxia hipolimnética, lo que a su vez, impide el establecimiento y desarrollo de fauna bentónica en el Lago Alchichica, favorece la pérdida interna de nitrógeno por desnitrificación y consecuentemente, conlleva a que el nitrógeno sea el elemento que más frecuentemente límite el crecimiento fitoplanctónico. Abstract in english The aim of this study is to recognize the existence of a pelagic-benthic coupling in the oligotrophic, tropical Lake Alchichica through analysis of the response of the deep benthic zone to the winter diatom bloom deposition. The water column phytoplankton biomass and the sedimentary chlorophyll a we [...] re analyzed along an annual cycle. Alchichica is a warm monomictic lake circulating in winter and stratified over the rest of the year. The presence of turbulence and nutrient availability during the mixing period, favor the development of a diatom bloom composed by large species (e. g., Cyclotella alchichicana) which are not totally consumed and settle down. The deep benthic zone responds to the sinking of the winter diatom bloom with the prompt development -and permanence for an extended period- of hypolimnetic anoxia, which in turns prevents the establishment and development of the benthic fauna in Lake Alchichica, and favors the internal loss of nitrogen through denitrification, and accordingly, promotes nitrogen to be the limiting nutrient for phytoplankton growth.

Alcocer, Javier; Escobar, Elva; Oseguera, Luis A..

133

Acoplamiento pelágico-bentónico: respuesta de la zona bentónica profunda a la sedimentación del florecimiento invernal de diatomeas en el lago oligotrófico Alchichica, Puebla, México Pelagic-benthic coupling: deep benthic zone response to winter diatom bloom sinking in oligotrophic Lake Alchichica, Puebla, Mexico  

Directory of Open Access Journals (Sweden)

Full Text Available El objetivo del presente estudio es reconocer la existencia de un acoplamiento pelágico-bentónico en el lago oligotrófico tropical Alchichica evaluando la respuesta de la zona bentónica profunda a la sedimentación del florecimiento invernal de diatomeas. Se midió la biomasa fitoplanctónica en la columna de agua a lo largo de un ciclo anual, al igual que la concentración de clorofila a sedimentaria. Alchichica es un lago monomíctico cálido con un periodo de circulación invernal y estratificación el resto del año. La presencia de turbulencia y nutrimentos durante el periodo de circulación favorecen el desarrollo de un florecimiento de diatomeas compuesto por especies de talla grande (p. e., Cyclotella alchichicana, las cuales se sedimentan al no ser consumidas en su totalidad. La zona bentónica profunda del lago responde a la sedimentación del florecimiento invernal de diatomeas con el desarrollo y permanencia por un periodo prolongado de anoxia hipolimnética, lo que a su vez, impide el establecimiento y desarrollo de fauna bentónica en el Lago Alchichica, favorece la pérdida interna de nitrógeno por desnitrificación y consecuentemente, conlleva a que el nitrógeno sea el elemento que más frecuentemente límite el crecimiento fitoplanctónico.The aim of this study is to recognize the existence of a pelagic-benthic coupling in the oligotrophic, tropical Lake Alchichica through analysis of the response of the deep benthic zone to the winter diatom bloom deposition. The water column phytoplankton biomass and the sedimentary chlorophyll a were analyzed along an annual cycle. Alchichica is a warm monomictic lake circulating in winter and stratified over the rest of the year. The presence of turbulence and nutrient availability during the mixing period, favor the development of a diatom bloom composed by large species (e. g., Cyclotella alchichicana which are not totally consumed and settle down. The deep benthic zone responds to the sinking of the winter diatom bloom with the prompt development -and permanence for an extended period- of hypolimnetic anoxia, which in turns prevents the establishment and development of the benthic fauna in Lake Alchichica, and favors the internal loss of nitrogen through denitrification, and accordingly, promotes nitrogen to be the limiting nutrient for phytoplankton growth.

Javier Alcocer

2008-08-01

134

Woodland communities in the Chilean cold-temperate zone (Baker and Pascua basins): Floristic composition and morpho-ecological transition / Comunidades leñosas en la zona chilena frío-templada (cuencas de los ríos Baker y Pascua): Composición florística y transición morfo-ecológica  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Este estudio describe la composición florística y la transición morfo-ecológica de las comunidades leñosas ocurriendo a través de un gradiente climático en la zona templada fría de la Patagonia chilena. Se establecieron un total de 256 relevamientos fitosociológicos a través de un transecto NE-SO de [...] 150 km para registrar las especies de plantas vasculares. Técnicas de clasificación (análisis de conglomerados) y ordenación (análisis de componentes principales) fueron usadas para segregar y examinar comunidades. Se computaron indicadores de biodiversidad incluyendo riqueza y abundancia de especies nativas y exóticas, valores de importancia, formas de vida de Raunkiaer, índices de diversidad y especies indicadoras para describir atributos comunitarios. La diversidad Beta fue analizada usando el coeficiente de Jaccard. Se discuten también las perturbaciones antropogénicas que actualmente afectan a la vegetación. En total se segregaron 11 comunidades pertenecientes a tres grupos ecológicos: a) comunidades leñosas meso-higromórficas pertenecientes a la cuenca del Baker, conformada principalmente de bosques caducifolios conteniendo valores relativos intermedios de riqueza y diversidad, pero las mayores riquezas de exóticas; b) comunidades leñosas higromórficas pertenecientes al segmento sur de la cuenca del río Baker y a través de toda la cuenca del río Pascua, compuesta de bosques siempreverdes conteniendo los mayores valores de riqueza y diversidad y muy baja riqueza de exóticas, y c) comunidades leñosas achaparradas alto-andinas, distribuidas en lugares de alta elevación en ambas cuencas, compuestas de krummholz conteniendo la menor riqueza y diversidad, sin presencia de especies introducidas. El reemplazo de comunidades caduficolias por siempreverdes en sentido norte-sur sucede alrededor de la latitud 48°S. Perturbaciones antrópicas como la tala de madera por propietarios rurales, sobrepastoreo por ganado doméstico y ampliaciones en los caminos, están provocando invasiones biológicas en los bosques de la cuenca del río Baker, mientras que los bosques de la cuenca del río Pascua, donde no ocurre poblamiento humano, permanecen prístinos Abstract in english This study describes the floristic composition and morpho-ecological transition of woodlands along a climatic gradient in the southern cold temperate zone of Chilean Patagonia. A total of 256 phytosociological relevés were performed across a 150 km NE-SW transect to record vascular plant species. Cl [...] assification (cluster analysis) and ordination (principal component analysis) techniques were used to segregate and examine the communities. Biodiversity indicators including richness and abundances of species natives and exotics, importance values, Raunkiaer plant life-forms, diversity indices and indicator species were calculated to describe community attributes. Beta diversity was analysed using the Jaccard index. Additionally, the current anthropogenic disturbances affecting this vegetation are discussed. In total, 11 woodland communities belonging to 3 morpho-ecological groups were segregated: a) meso-hygromorphic woodlands belonging to the Baker basin, mostly composed of deciduous forests containing relatively moderate values of richness and diversity but high richness of exotics, b) hygromorphic woodlands belonging to the southern segment of the Baker basin and along the Pascua basin, composed of evergreen forest containing the relatively highest values of richness and diversity and very low richness of exotics and c) high-Andean dwarf woodlands distributed at high elevations in both basins, composed of deciduous krummholz containing the lowest richness and diversity and no exotics. The replacement of deciduous by evergreen communities at low elevations occurs around the latitude 48°S. Anthropogenic disturbances like logging by rural landowners, overgrazing by livestock and road construction are promoting biological invasions in the Baker basin fo

VIDAL, OSVALDO J; BANNISTER, JAN R; SANDOVAL, VÍCTOR; PÉREZ, YESSICA; RAMÍREZ, CARLOS.

135

Analysis of winter greenhouse  

Energy Technology Data Exchange (ETDEWEB)

In this note, an analysis of a winter greenhouse is presented. Effects of various parameters viz. ventilation/infiltration, relative humidity, movable insulation etc. have been incorporated in the analysis and their effect on the performance of the greenhouse has also been studied. On the basis of numerical calculations, some interesting conclusions have been made.

Tiwari, G.N.

1984-01-01

136

The News. Winter 2007  

Science.gov (United States)

This Winter 2007 quarterly newsletter from the Community College League of California includes: (1) Incumbents: Some Win, Some Lose in November Trustee Elections; (2) Voters Approve $2 Billion in Bonds; (3) Photos from the "Together We Can" conference; (4) Report, Media Criticize Transfer, Completion Rates and Colleges; (5) District Leader…

Giles, Ray, Ed.

2007-01-01

137

Presence of Dalbulus maidis (Hemiptera: Cicadellidae) and of Spiroplasma kunkelii in the temperate region of Argentina.  

Science.gov (United States)

"Corn stunt" is one of the main corn (Zea mays L.) diseases in the Americas and Dalbulus maidis (DeLong & Wolcott) is the key vector of the pathogen Spiroplasma kunkelii Whitcomb. In Argentina, the corn-producing area is in the temperate region, where vector and pathogen prevalence levels are unknown. In this study, the prevalence and distribution of D. maidis and S. kunkelii in the temperate region of Argentina and D. maidis overwintering ability in this region were determined. Surveys were conducted in 2005-2006 and 2006-2007 seasons to determine D. maidis and S. kunkelii presence, and in winter 2006 to determine the vector overwintering ability. The highest S. kunkelii prevalence and incidence levels were found in the transition area from the temperate to the subtropical region, related to the highest D. maidis prevalence and insects sampled per location. D. maidis adults were found in volunteer corn plants and spontaneous vegetation in autumn and winter months, which were inoculative for the pathogen S. kunkelii. This overwintering ability was related to detection of D. maidis insects in corn crops at early growth stages in the following growing season. This work emphasizes that corn stunt disease is present in the temperate region of Argentina, and this highlights the need to develop proper agronomic practices like monitoring insect vector populations and controlling voluntary plants. This study also indicates that further research is needed to understand the potential yield reduction caused by this pathogen on symptomless plants and population dynamics of the insect vector. PMID:24020268

Carloni, E; Carpane, P; Paradell, S; Laguna, I; Pecci, M P Giménez

2013-08-01

138

Winter Storms and Extreme Cold  

Science.gov (United States)

... it strikes. Before During After More Information Before Winter Storms and Extreme Cold To prepare for a ... until emergency personnel arrive to assist you. During Winter Storms and Extreme Cold Stay indoors during the ...

139

Titan's Winter Polar Vortex  

Science.gov (United States)

Titan's atmosphere has provided an interesting study in contrasts and similarities with Earth's. While both have N$_2$ as the dominant constituent and comparable surface pressures $\\sim1$ bar, Titan's next most abundant molecule is CH$_4$, not O$_2$, and the dissociative breakup of CH$_4$ and N$_2$ by sunlight and electron impact leads to a suite of hydrocarbons and nitriles, and ultimately the photochemical smog that enshrouds the moon. In addition, with a 15.95-day period, Titan is a slow rotator compared to Earth. While the mean zonal terrestrial winds are geostrophic, Titan's are mostly cyclostrophic, whipping around the moon in as little as 1 day. Despite the different dynamical regime, Titan's winter stratosphere exhibits several characteristics that should be familiar to terrestrial meteorologists. The cold winter pole near the 1 -mbar level is circumscribed by strong winds (up to 190 m/s) that act as a barrier to mixing with airmasses at lower latitudes. There is evidence of enhancement of several organic species over the winter pole, indicating subsidence. The adiabatic heating associated with this subsidence gives rise to a warm anomaly at the 0.01-mbar level, raising the stratopause two scale heights above its location at equatorial latitudes. Condensate ices have been detected in Titan's lower stratosphere within the winter polar vortex from infrared spectra. Although not always unambiguously identified, their spatial distribution exhibits a sharp gradient, decreasing precipitously across the vortex away from the winter pole. The interesting question of whether there is important heterogeneous chemistry occurring within the polar vortex, analogous to that occurring in the terrestrial polar stratospheric clouds in the ozone holes, has not been addressed. The breakup of Titan's winter polar vortex has not yet been observed. On Earth, the polar vortex is nonlinearly disrupted by interaction with large-amplitude planetary waves. Large-scale waves have not been identified in Titan's atmosphere, so the decay of its polar vortex may be more gradual than on Earth. Observations from an extended Cassini mission into late northern spring should provide critical data indicating whether the vortex goes away with a bang or just fades away.

Flasar, F.M.; Achterberg, R.K.; Schinder, P.J.

2008-01-01

140

Hydrogen embrittlement susceptibility of tempered 9%Cr-1% Mo steel  

International Nuclear Information System (INIS)

The influence of the subsurface hydrogen activity on the hydrogen embrittlement (HE) susceptibility of a tempered 9%Cr-1%Mo ferritic-martensitic steel (T91) has been studied by constant extension rate tests (CERT) performed under cathodic charging during straining at 20 degrees C. changes in the hydrogen activity on the surface were obtained by varying the cathodic current density imposed during a tensile test completed to fracture. The broken samples were observed by scanning electron microscopy (SEM). The results show a strong dependence of the extent of the brittle zone with the subsurface hydrogen activity. This effect could be attributed to an enhancement of the apparent diffusion coefficient of hydrogen when increasing H activity. Increasing H activity could enhance both the trapping rate on pre-existing and strain-induced traps and H dragging by moving traps such as dislocations. (authors)

2011-01-01

 
 
 
 
141

Editorial - The winter Atomiades  

CERN Multimedia

As we wrote in our previous editorial, the Staff Association gives direct support to sports events, such as the Atomiades, a section of the Association of Sports Communities of European Research Institutes, which brings together sportsmen and women from 38 European research centres in 13 countries (Austria, Belgium, Czech Republic, United Kingdom, Finland, France, Germany, Hungary, Italy, Luxemburg, the Netherlands, Russia, and Switzerland). The summer Atomiades take place between the months of June and September every three years. Thirteen such events have taken place since 1973, the last one in June 2009 in Berlin. As far as the winter Atomiades are concerned, also organized every three years, and alternating with the summer Atomiades, there have been eleven since 1981, the last one at the end of January this year in neighbouring France. The following article tells the wonderful adventure of the CERN staff who took part in this event. A positive outcome for CERN skiers at the winter Atomiades The 11t...

Staff Association

2011-01-01

142

The winter peak in the occurrence of acute aortic dissection is independent of climate.  

Science.gov (United States)

We recently reported the existence of a higher risk of acute aortic dissection (AAD) during the winter months. However, it is not known whether this winter peak is affected by climate. To address this issue, we evaluated data from 969 AAD patients who were enrolled at various sites around the globe and who were participating in the International Registry of Acute Aortic Dissection (IRAD). We found a significant (p = 0.001; chi2 test) difference in the number of AAD events occurring during the different seasons of the year, with highest incidence in winter (28.4%) and lowest incidence in summer (19.9%). Furthermore, the winter peak was evident in both cold and temperate climate settings, suggesting that the relative change in temperature, rather than absolute temperature, and/or endogenous annual rhythms are critical mechanistic factors. PMID:16147902

Mehta, Rajendra H; Manfredini, Roberto; Bossone, Eduardo; Fattori, Rossella; Evagelista, Arturo; Boari, Benedetta; Cooper, Jeanna V; Sechtem, Udo; Isselbacher, Eric M; Nienaber, Christoph A; Eagle, Kim A

2005-01-01

143

Winter maintenance and cycleways  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Increasing cycling as a means of personal travel couldgenerate environmental benefits if associated with acorresponding decrease in car-based transport. In seeking topromote cycling in wintertime, it is desirable to understandhow important the road surface condition is compared to otherfactors in people's decision to cycle or not. In this thesis,the possibility of increasing the number of cyclists byimproving the winter maintenance servicelevel on cycleways isexamined. The attitudes towards c...

Bergstro?m, Anna

2002-01-01

144

Al's Winter Storm Activity  

Science.gov (United States)

This project explores factors that help create severe winter weather. An interactive simulation provides hands-on experience, followed by guiding questions and resource exploration. Form groups of three. Explore the following simulation: Weather Maker Simulator Use the simulation to answer the following questions on paper. 1. In general, when are winds formed? 2. When winds are blowing, how can you get them to stop? 3. What usually happens when there is a large difference between the temperatures? 4. What happens when there ...

Al

2010-02-22

145

Winter in Bavaria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

"A Winter In Bavaria" was written on location in Regensburg, Germany, and is the first-hand account of a cataclysm, already predicted by Nostradamus, which changed the direction of Bavarian culture forever. Anything vaguely resembling an allusion to any real person or institution is entirely coincidental, has no foundation in fact and is clearly the product of a mind estranged - except that Bavarian beer is, by and large, still to be highly recommended.

Anthony Stephens

2004-01-01

146

Well-Tempered Metadynamics Converges Asymptotically  

Science.gov (United States)

Metadynamics is a versatile and capable enhanced sampling method for the computational study of soft matter materials and biomolecular systems. However, over a decade of application and several attempts to give this adaptive umbrella sampling method a firm theoretical grounding prove that a rigorous convergence analysis is elusive. This Letter describes such an analysis, demonstrating that well-tempered metadynamics converges to the final state it was designed to reach and, therefore, that the simple formulas currently used to interpret the final converged state of tempered metadynamics are correct and exact. The results do not rely on any assumption that the collective variable dynamics are effectively Brownian or any idealizations of the hill deposition function; instead, they suggest new, more permissive criteria for the method to be well behaved. The results apply to tempered metadynamics with or without adaptive Gaussians or boundary corrections and whether the bias is stored approximately on a grid or exactly.

Dama, James F.; Parrinello, Michele; Voth, Gregory A.

2014-06-01

147

Raising the temper-?-spot analysis of temper inclusions in experimental ceramics  

International Nuclear Information System (INIS)

Provenancing of ancient ceramics is a highly important scientific tool for archaeological studies. In general, ceramics are not made from the original clay as it is found in deposits. To produce the needed physical properties in the finished product, the clay has to be either tempered by adding sands or biological materials, or levigated, to remove the coarse fraction. Thus, the chemical composition of the finished ceramic differs from the composition of the original clay bed. To overcome this obfuscation, any information that can be gained about the temper is useful. In a small series, several pieces of ceramic were produced from known clay and tempers and the resulting ceramics analysed by neutron activation analysis (NAA). As many attempts to physically separate the temper from the clay matrix have failed, ?-spot analysis of temper inclusions was performed at the microbeam particle induced X-ray Emission (?-PIXE) facility in Rossendorf and with laser ablation inductively coupled plasma mass spectroscopy (LA-ICP-MS) at the Aberystwyth University in Wales. It could be shown that from a small number of measurements, a general impression of the temper used could be gained. Furthermore the ?-spot methods and the bulk data gained from INAA are highly comparable, extending the set of elements that can be measured. With this information, the influence of the temper on the bulk composition of the finished product can be estimated, which potentially adds crucial information to subsequent dilution calculations. (author)

2012-01-01

148

Arithmetic Brownian motion subordinated by tempered stable and inverse tempered stable processes  

CERN Multimedia

In the last decade the subordinated processes have become popular and found many practical applications. Therefore in this paper we examine two processes related to time-changed (subordinated) classical Brownian motion with drift (called arithmetic Brownian motion). The first one, so called normal tempered stable, is related to the tempered stable subordinator, while the second one - to the inverse tempered stable process. We compare the main properties (such as probability density functions, Laplace transforms, ensemble averaged mean squared displacements) of such two subordinated processes and propose the parameters' estimation procedures. Moreover we calibrate the analyzed systems to real data related to indoor air quality.

Wy?oma?ska, Agnieszka

2012-01-01

149

Comportamiento de vacas Holstein mantenidas en un sistema de estabulación libre, en invierno, en zona árida, México / Behaviour of Holstein cows under a free housing system, in winter, in an arid zone, México  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish El objetivo de esta investigación fue evaluar el comportamiento individual y social de vacas lecheras bajo un sistema de estabulación libre durante el invierno y entre períodos de alimentación. El estudio se realizó durante 60 días en un hato productor de leche en el Estado de Aguascalientes, México [...] , con 40 vacas Holstein en producción de entre 2 a 4 años de edad. Las vacas estaban en un solo corral y con un espacio de 40 m²/vaca. Los resultados mostraron que las vacas destinaron 51% del tiempo en descansar echadas, 29% para rumiar, 10% para comer, 4% para caminar, 4% permanecieron paradas, y 2% para colear; no hubo conductas de sacudidas (movimiento costal), orejear, cabecear y patear. Para conductas sociales se observó una frecuencia de interacciones afiliativas de 6,1/hora, y 0,95/hora de interacciones agresivas; dentro de las conductas afiliativas emitidas a otras vacas se identificó una frecuencia para lamer de 4,9/hora, oler de 0,61/hora, recargarse de 0,24/ hora, montar de 0,18/hora y rascarse de 0,12/hora; dentro de las conductas agresivas se identificaron las de seguir, amenazar y topetear a otras vacas con valores de 0,63/hora, 0,10/hora y 0,22/hora, respectivamente. Las vacas presentaron conductas de mantenimiento y sociales que sugieren un estado de bienestar, atribuible a la temperatura ambiente predominante en la época de estudio, el espacio individual asignado a cada animal y al horario en que se registraron las conductas. Abstract in english The objective of this trial was to assess the social and individual behaviour of dairy cows under free housing conditions, during a winter season and between feeding periods. The study considered 60 days of observations using 40 Holstein cows (2-4 years old) from a dairy herd in the state of Aguasca [...] lientes. The cows were all kept in one pen with a space allowance of 40m²/cow. Individual behaviour data showed that cows spent 51% of their time resting in a lying position, 29% ruminating, 10% eating, 4% walking, 4% standing and 2% tail switching. No evidence of body quivering, ear twitching, head tossing or kicking was found. Social behaviour data showed that affiliation interactions occurred 6.1 times per hour and aggressive interactions 0.95 times per hour. Regarding affiliation behaviour it was found that licking, smelling, replenishing, mounting and scratching other cows occurred 4.9/hour, 0.61/hour, 0.24/hour, 0.18/hour and 0.12/hour respectively. Regarding aggressive behaviour the following was recorded: cows following, threatening and butting other cows occurred 0.63/hour, 0.10/hour and 0.22/hour respectively. The cows showed maintenance and social behaviours that suggest a welfare state attributable to the environmental temperature that was predominant during the season of study, the individual space assigned per cow and the time schedule in which the observations were made.

I., Vitela; C., Cruz-Vázquez; J., Solano.

150

Big6 Winter Production  

Science.gov (United States)

Goals: a. Students will be able to identify the four seasons. b. Students will be able to identify three animals (bear, goose, moose) and know their lifestyle patterns in congruence with the four seasons, especially Winter months. c. Students will develop an understanding of their environment. 2nd Grade Standard III: Students will develop an understanding of their environment Objective 2: Observe and describe weather Goal C: Describe how weather affects people and weather Lesson Objectives: a. Identify the seasons and represent each with pictures and songs. b. Observe and describe typical weather for each of ...

Cook, Mrs.

2010-11-05

151

Chaffinch and Winter Wren  

Science.gov (United States)

Every morning when he walks the dog, retired professor of natural history Peter Slater can identify as many as thirty birds by their song alone. On a walk in a Scottish town with Ari Daniel Shapiro, Slater explains what two common songsters, the chaffinch and winter wren, are singing about, and how even city dwellers can learn to âbird by earâ in their own neighborhoods, with rewarding results. Also included is a Learn More section that provides background information on the scientists recorded in the podcast, lessons, images, and cool facts.

2009-01-01

152

Winter Frost and Fog  

Science.gov (United States)

This somewhat oblique blue wide angle Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows the 174 km (108 mi) diameter crater, Terby, and its vicinity in December 2004. Located north of Hellas, this region can be covered with seasonal frost and ground-hugging fog, even in the afternoon, despite being north of 30oS. The subtle, wavy pattern is a manifestation of fog. Location near: 28oS, 286oW Illumination from: upper left Season: Southern Winter

2005-01-01

153

Tempering of Iron-Carbon-Nitrogen Martensites.  

Science.gov (United States)

The tempering behavior of ternary FeCN martensitic specimens, with a total amount of interstitials of about 5.5 at. percent and carbon and nitrogen contents between about 1.5 at. percent and 3.9 at. percent, was investigated in the temperature range of 10...

C. Liu A. Boettger E. J. Mittemeijer

1990-01-01

154

Mercury emission from a temperate lake during autumn turnover.  

Science.gov (United States)

Lakes in temperate regions stratify during summer and winter months, creating distinct layers of water differentiated by their physical and chemical characteristics. When lakes mix in autumn and spring, mercury cycling may be affected by the chemical changes that occur during mixing. Sampling was conducted in Lake Lacawac, Eastern Pennsylvania, USA, throughout the autumn of 2007 to characterize changes in emission of gaseous elemental mercury (Hg(0)) from the lake surface and dissolved mercury profiles in the water column during mixing. Water chemistry and weather parameters were also measured, including dissolved organic carbon (DOC), iron, and solar radiation which have been shown to interact with mercury species. Results indicate that emission of Hg(0) from the lake to the atmosphere during turnover was controlled both by solar radiation and by surface water mercury concentration. As autumn turnover progressed through the months of October and November, higher mercury concentration water from the hypolimnion mixed with epilimnetic water, increasing mercury concentration in epilimnetic waters. Dissolved absorbance was significantly correlated with mercury concentrations and with iron, but DOC concentrations were essentially constant throughout the study period and did not exhibit a relationship with either dissolved mercury concentrations or emission rates. Positive correlations between dissolved mercury and iron and manganese also suggest a role for these elements in mercury transport within the lake, but iron and manganese did not demonstrate a relationship with emission rates. This research indicates that consideration of seasonal processes in lakes is important when evaluating mercury cycling in aquatic systems. PMID:19200586

Wollenberg, Jennifer L; Peters, Stephen C

2009-04-01

155

Mercury emission from a temperate lake during autumn turnover  

International Nuclear Information System (INIS)

Lakes in temperate regions stratify during summer and winter months, creating distinct layers of water differentiated by their physical and chemical characteristics. When lakes mix in autumn and spring, mercury cycling may be affected by the chemical changes that occur during mixing. Sampling was conducted in Lake Lacawac, Eastern Pennsylvania, USA, throughout the autumn of 2007 to characterize changes in emission of gaseous elemental mercury (Hg0) from the lake surface and dissolved mercury profiles in the water column during mixing. Water chemistry and weather parameters were also measured, including dissolved organic carbon (DOC), iron, and solar radiation which have been shown to interact with mercury species. Results indicate that emission of Hg0 from the lake to the atmosphere during turnover was controlled both by solar radiation and by surface water mercury concentration. As autumn turnover progressed through the months of October and November, higher mercury concentration water from the hypolimnion mixed with epilimnetic water, increasing mercury concentration in epilimnetic waters. Dissolved absorbance was significantly correlated with mercury concentrations and with iron, but DOC concentrations were essentially constant throughout the study period and did not exhibit a relationship with either dissolved mercury concentrations or emission rates. Positive correlations between dissolved mercury and iron and manganese also suggest a role for these elements in mercury transport within the lake, but iron and manganese did not demonstrate a relationship with emission rates. This research indicates that consideration of seasonal processes in lakes is important when evaluating mercury cycling in aquatic systems

2009-04-01

156

[Suitability evaluation of great bustard (Otis tarda)'s wintering habitat in Baiyangdian basin].  

Science.gov (United States)

Based on the related researches of great bustard's wintering habitat selection as well as the advices of related experts and the distribution records of great bustard in Baiyangdian basin, 3 first class indices and 13 second indices were chosen to characterize the key factors affecting the wintering habitat selection of great bustard, and a habitat quality evaluation model was built to assess the quality of wintering habitat selection of great bustard in Baiyangdian basin. In 2005, the suitable wintering habitats of great bustard in the basin had an area of 11907.25 km2, accounting for 34.1% of the total. Of the suitable wintering habitats, the most suitable habitats had an area of 4596.25 km2, only 13.2% of the total and comparatively concentrated in two zones, i.e., Baiyangdian Wetland Natural Reserve and its peripheral area (zone I) in the east of Baiyangdian basin, and Xingtang and Quyang counties (zone II) in the southwest of Baiyangdian basin. The total area of the most suitable habitats in zone I and zone II was 2803.55 km2, accounting for 61.0% of the most suitable habitats in the basin. To protect the wintering habitat of great bustard in the basin, proper measures should be taken according to the environmental features of the two zones. PMID:22007472

Zhao, Zhi-xuan; Yan, Deng-hua; Weng, Bai-sha; Zhang, Biao

2011-07-01

157

Excess Winter Mortality and Cold Temperatures in a Subtropical City, Guangzhou, China  

Science.gov (United States)

Background A significant increase in mortality was observed during cold winters in many temperate regions. However, there is a lack of evidence from tropical and subtropical regions, and the influence of ambient temperatures on seasonal variation of mortality was not well documented. Methods This study included 213,737 registered deaths from January 2003 to December 2011 in Guangzhou, a subtropical city in Southern China. Excess winter mortality was calculated by the excess percentage of monthly mortality in winters over that of non-winter months. A generalized linear model with a quasi-Poisson distribution was applied to analyze the association between monthly mean temperature and mortality, after controlling for other meteorological measures and air pollution. Results The mortality rate in the winter was 26% higher than the average rate in other seasons. On average, there were 1,848 excess winter deaths annually, with around half (52%) from cardiovascular diseases and a quarter (24%) from respiratory diseases. Excess winter mortality was higher in the elderly, females and those with low education level than the young, males and those with high education level, respectively. A much larger winter increase was observed in out-of-hospital mortality compared to in-hospital mortality (45% vs. 17%). We found a significant negative correlation of annual excess winter mortality with average winter temperature (rs=-0.738, P=0.037), but not with air pollution levels. A 1 °C decrease in monthly mean temperature was associated with an increase of 1.38% (95%CI:0.34%-2.40%) and 0.88% (95%CI:0.11%-1.64%) in monthly mortality at lags of 0-1 month, respectively. Conclusion Similar to temperate regions, a subtropical city Guangzhou showed a clear seasonal pattern in mortality, with a sharper spike in winter. Our results highlight the role of cold temperature on the winter mortality even in warm climate. Precautionary measures should be strengthened to mitigate cold-related mortality for people living in warm climate.

Yang, Jun; Chau, Patsy Yuen-Kwan; Yang, Lin; Chen, Ping-Yan; Wong, Chit-Ming

2013-01-01

158

Spirit's Winter Work Site  

Science.gov (United States)

[figure removed for brevity, see original site] Annotated Version This portion of an image acquired by the Mars Reconnaissance Orbiter's High Resolution Imaging Science Experiment camera shows the Spirit rover's winter campaign site. Spirit was parked on a slope tilted 11 degrees to the north to maximize sunlight during the southern winter season. 'Tyrone' is an area where the rover's wheels disturbed light-toned soils. Remote sensing and in-situ analyses found the light-toned soil at Tyrone to be sulfate rich and hydrated. The original picture is catalogued as PSP_001513_1655_red and was taken on Sept. 29, 2006. NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

2006-01-01

159

Relating Leaf Nitrogen, Leaf Photosynthesis and Canopy CO2 Exchange in a Temperate Winter Barley Field  

Science.gov (United States)

Net exchange of CO2 between the atmosphere and the soil-vegetation interface (NEE) is controlled by a wide range of biochemical and biophysical processes where leaf photosynthesis is often the most important. In mechanistically and physically based photosynthesis models (e.g. Farquhar et al. 1980) leaf nutrient status is a limiting factor for the photosynthetic capacity since it is implicitly incorporated through the parameters of maximum rate of carboxylation of CO2 (Vcmax) and the maximum rate of electron transport (Jmax). These are closely related to leaf nitrogen concentration (Na) and leaf chlorophyll content (Cab) and often show a characteristic seasonal dynamic. When simulating CO2 exchange, model outputs are sensitive to leaf photosynthetic capacity, which is labour consuming to verify through field measurements. A less time consuming method is to measure leaf "greenness" (SPAD), which is closely related to chlorophyll content and thus photosynthetic capacity. In the present study field measurements of leaf photosynthesis (LI-6400, LICOR Inc.), leaf reflectance (SPAD-502, Minolta), and LAI (LAI-2000, LICOR Inc.) were conducted on agricultural fields in Western Denmark during one growing season. The leaf photosynthesis measurements provided the basis for estimating photosynthetic capacity. SPAD measurements and LAI was measured with a higher spatial and temporal resolution. SPAD readings were calibrated against Cab and Na analyzed on leaf material in the laboratory and later correlated to photosynthetic capacity. These data were used to parameterize a coupled photosynthesis and stomatal model that was run for the growing season 2012 to estimate NEE. As a part of the hydrological observatory HOBE (hobe.dk), fluxes of greenhouse gasses are continuously measured by eddy covariance systems at three field sites in the Skjern River Catchment, Western Denmark, providing the basis for estimating the exchange of energy, water vapour, and CO2 on canopy scale. One of the sites is situated at the field under investigation in the present study. Here we compare modeled NEE with the measured CO2 fluxes. The presented approach is shown to provide an efficient field sampling method for model parameterization with high temporal and spatial resolution and a physiological basis for scaling fluxes from leaf level to canopy scale. We further evaluate the potential for applying the model approach in connection with upscaling by means of satellite data.

Jensen, R.; Boegh, E.; Herbst, M.; Friborg, T.

2012-12-01

160

Winter fuels report  

Energy Technology Data Exchange (ETDEWEB)

The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition and underground storage for the United States and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the United States and selected cities; and US total heating degree-days by city. 27 figs, 12 tabs.

1990-11-29

 
 
 
 
161

Spirit Scans Winter Haven  

Science.gov (United States)

At least three different kinds of rocks await scientific analysis at the place where NASA's Mars Exploration Rover Spirit will likely spend several months of Martian winter. They are visible in this picture, which the panoramic camera on Spirit acquired during the rover's 809th sol, or Martian day, of exploring Mars (April 12, 2006). Paper-thin layers of light-toned, jagged-edged rocks protrude horizontally from beneath small sand drifts; a light gray rock with smooth, rounded edges sits atop the sand drifts; and several dark gray to black, angular rocks with vesicles (small holes) typical of hardened lava lie scattered across the sand. This view is an approximately true-color rendering that combines images taken through the panoramic camera's 753-nanometer, 535-nanometer, and 432-nanometer filters.

2006-01-01

162

Winter fuels report  

International Nuclear Information System (INIS)

The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; propane net production, imports and stocks on a US level and for PADD's I, II, and III; natural gas supply and disposition and underground storage for the US and consumption for all PADD's, as well as selected National average prices; residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil and petroleum price comparisons for the US and selected cities; and a 6-10 day, 30-Day, and 90-Day outlook for temperature and precipitation and US total heating degree-days by city

1995-01-01

163

Tarsiut winter alert monitoring  

Energy Technology Data Exchange (ETDEWEB)

Tarsiut Island is the first caisson retained island that has been built for drilling operations in the Arctic Offshore. Because of its novelty, a real time monitoring program involving the predicted and observed performance of the island under ice loading was established to ensure safe and efficient drilling operations and to satisfy government requirements. To accomplish this program, an extensive state of the art instrumentation, data acquisition and monitoring system was developed and utilized to collect ice action and island response information. The data was used in real time to assess island stability and provide an alert warning to drilling personnel. The alert levels were related to drilling activities to ensure the integrity of the operation. This paper describes the methodology, procedures and experiences associated with the Tarsiut winter monitoring program.

Wright, B.D.; Weaver, J.S.

1983-05-01

164

Winter fuels report  

Energy Technology Data Exchange (ETDEWEB)

The Winter Fuels Report is intended to provide consise, timely information to the industry, the press, policymakers, consumers, analysts, and State and local governments on the following topics: Distillate fuel oil net production, imports and stocks on a US level and for all Petroleum Administration for Defense Districts (PADD) and product supplied on a US level; Natural gas supply and disposition and underground storage for the US and consumption for all PADD`s as well as selected National average prices; Residential and wholesale pricing data for heating oil and propane for those States participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; Crude oil and petroleum price comparisons for the US and selected cities; and A 6-10 Day and 30-Day outlook for temperature and precipitation and US total heating degree days by city.

1995-02-17

165

[Pteridophytes that indicate environmental alteration in the temperate forest of San Jerónimo Amanalco, Texcoco, Mexico].  

Science.gov (United States)

Pteridophytes that indicate environmental alteration in the San Jer6nimo Amanalco temperate forest, Texcoco, Mexico. The patterns of distribution of 26 pteridophyte species were studied as possible indicators of environmental alteration in the temperate forest of San Jer6nimo Amanalco, Texcoco, State of Mexico. The presence and abundance of the pteridoflora was studied in relation to edaphic, topographic and vegetation variables in 100 sampling locations within an area of 494 hectares. The relationship between these variables was studied using Canonical Correspondence Analysis. Five landscapes were recognized in the study zone according to the degree of deterioration: severe erosion, erosion, mountain with moderate reversible deterioration, mountain with no evident deterioration, and canyon with no evident deterioration. Cheilanthes bonariensis and Pellaea ternifolia are indicators of environmental degradation. The taxa that only grow in landscapes without apparent alteration are Adiantum andicola, Adiantum poiretii, Argyrochosma incana, Asplenium blepharophorum, Dryopteris pseudo filix-mas, Equisetum hyemale and Pteris cretica. PMID:19256434

Lucía Rodríguez, Romero; Pacheco, Leticia; Zavala Hurtado, José Alejandro

2008-06-01

166

Temper process line; Tenpa process line  

Energy Technology Data Exchange (ETDEWEB)

This facility was delivered to Asan factory of Dongbu Steel (Korea) for continuous temper rolling and tension leveling of hot and cold rolled coils. Main specifications: (1) Material to be handled: annealed cold or hot rolled steel sheet, (2) Sheet thickness and width: 0.3-3.2mm x 700-1,640mm, (3) Processing speed: 900m/min maximum, (4) Rolling mill: 4 Hi dry/wet changeable hydraulic depression system, (5) Tension leveler: 6 Hi dry system. Features: (1) Continuous high- efficiency processes including temper rolling, tension leveling, side trimming, inspection, oiling, off-gauge cutting and piling after batch annealing, (2) Highest capability of 900mpm in line speed over the world, (3) Side trimmer with a non-stop width change mechanism for preventing the roll mark of a mill leveler, (4) Automated processes including band cut and coil tip extraction after batch annealing. (translated by NEDO)

NONE

2000-04-20

167

Monitoring Rehabilitation in Temperate North American Estuaries  

Energy Technology Data Exchange (ETDEWEB)

In this chapter, we propose that monitoring rehabilitation in estuarine ecosystems by necessity requires quantifying relationships between dynamic estuarine processes and sensitive indicators of ecosystem function. While we do discuss temperate systems in general, emphasis is placed on anadromous salmon habitats in the Pacific Northwest because anadromous fishes are such a major focus of rehabilitation efforts, and present some of the greater challenges in linking function of one segment of their life history to conditions in a specific habitat. We begin with a basic overview of the ecological and socioeconomic significance of, as well as anthropogenic effects on, estuaries. Next, we briefly summarize the various kinds of estuarine rehabilitation historically practiced in temperate regions, and review estuarine rehabilitation monitoring design and methods, highlighting the unique challenges involved in monitoring estuarine systems. We then close with a summary and conclusions.

Rice, Casimir A.; Hood, W Gregory; Tear, Lucinda M.; Simenstad, Charles; Williams, Gregory D.; Johnson, L. L.; Feist, B. E.; Roni, P.

2005-02-01

168

AGEING AND TEMPERING OF FERROUS MARTENSITES  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The low temperature ageing of a Fe-15wt%Ni-1wt%C martensite (Ms temperature -35 C) has been investigated using field - ion microscopy and atom probe microanalytical techniques. It is demonstrated that both the amplitude and the wavelength of the carbon composition fluctuations observed during room-temperature ageing increase with time, indicating that the alloy decomposes by a spinodal process. The carbon-rich regions approach a limiting composition of Fe8C during this reaction. The tempering...

1986-01-01

169

Temperate coliphages: classification and correlation with habitats.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Temperate coliphages were recovered from sewage, mammalian feces, and lysogenic strains of Escherichia coli. A total of 32 phages of independent origin were divided into six groups by applying the criteria of host range, antigenic homology, and the ultraviolet inducibility of the prophage. The demonstration of genetic interactions in some cases has confirmed the classification scheme. Nine phages were assigned to the P2 family and 19 to the lambda family. The remaining four isolates may repre...

1980-01-01

170

On the support of tempered distributions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We show that if the summability means in the Fourier inversion formula for a tempered distribution f is an element of S'(R-n) converge to zero pointwise in an open set Omega, and if those means are locally bounded in L-1 (Omega), then Omega subset of R-n\\supp f. We prove this for several summability procedures, in particular for Abel summability, Cesaro summability and Gauss-Weierstrass summability.

Vindas Diaz, Jasson; Estrada, Ricardo

2010-01-01

171

Schwartz families in tempered distribution spaces  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we define Schwartz families in tempered distribution spaces and prove many their properties. Schwartz families are the analogous of infinite dimensional matrices of separable Hilbert spaces, but for the Schwartz test function spaces, having elements (functions) realizable as vectors indexed by real Euclidean spaces (ordered families of scalars indexed by real Euclidean spaces). In the paper, indeed, one of the consequences of the principal result (the character...

Carfi?, David

2011-01-01

172

Organic matter stocks in temperate forest soil  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In temperate forests, more than 60% of the total carbon reserves are located in forest floor and mineral soil. The main objectives of this study were (1) to investigate the composition and radiocarbon age of organic matter (OM) pools of different stability in mineral soils, (2) to identify associations between iron oxides and specific carbon species, and (3) to analyse the small scale spatial variability of soil organic carbon (SOC) stocks. Composition, radiocarbon age and associations betwee...

Scho?ning, Ingo

2006-01-01

173

Microstructural development in the heat-affected zone of a laser-cladded steel  

Energy Technology Data Exchange (ETDEWEB)

The surface of a medium carbon steel sheet was laser cladded with a Co-Cr alloy in two layers by a multi-pass technique. This study is concerned with the heat-affected zone (HAZ) created. Within this zone, austenitisation and martensite formation take place repeatedly twice or three times followed by later tempering. This change in microstructure is associated with a hardening and a softening. The microstructure consists of tempered martensite close to the heat source, an intermediate zone of tempered martensite/bainite and a partially transformed zone. However, the hardness is constant throughout the HAZ and decreases in the partially transformed zone to the substrate hardness. The analysis of the microstructure and the hardness are used to re-establish the temperature history encountered by the material in the HAZ. It could be shown that the HAZ has a translational symmetry that can be approximated by a 2-D sheet structure. (orig.)

Niederhauser, S.; Karlsson, B.; Sotkovszki, P. [Materials and Mfg. Technology, Chalmers Univ. of Technology, Goeteborg (Sweden)

2005-04-01

174

Tempering mechanism of solid-fat products. Kokei yushi seihin no tempering kiko  

Energy Technology Data Exchange (ETDEWEB)

Untemered margarine and butter as test pieces and a reference specimen (made up of cacao fat at 30% by weight and soya bean oil at 70% by weight), as well as those applied with tempering treatment are prepared. The solid content in the test pieces and the temperature dependency of particles sizes (in the range from 10 to 25 {degree} C) were measured using the permeability method developed by the authors, and their histological structures were observed using SEM. The result shows the following: (1) When the temperature of the untempered products is raised, the grain size in solid particles decreases suddenly at a certain temperature; (2) The tempered test pieces had their solid content and grain sizes decreased and the number of particles increased largely as compared with the untempered products; and (3) The solid particles being coagulates of micro particles present in the untempered products are destroyed by the tempering treatment, turning into dispersed micro particles. 7 refs., 9 figs.

Hirokawa, N. (Kanegafuchi Chemical Industry Co. Ltd., Osaka (Japan)); Harano, Y. (Fukuyama University, Hiroshima (Japan). Faculty of Engineering)

1991-08-20

175

Hydrology and morphology of two river mouth regions (temperate Vistula Delta and subtropical Red River Delta  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents a comparative analysis of two different river mouths from two different geographical zones (subtropical and temperate climatic regions. One is the multi-branch and multi-spit mouth of the Red River on the Gulf of Tonkin (Vietnam, the other is the smaller delta of the river Vistula on a bay of the Baltic Sea (Poland. The analysis focuses on the similarities and differences in the hydrodynamics between these estuaries and the adjacent coastal zones, the features of sediment transport, and the long-term morphodynamics of the river outlets. Salinity and water level are also discussed, the latter also in the context of the anticipated global effect of accelerated sea level rise. The analysis shows that the climatic and environmental conditions associated with geographical zones give rise to fundamental differences in the generation and dynamic evolution of the river mouths.

Zbigniew Pruszak

2005-09-01

176

Winter fuels report  

Energy Technology Data Exchange (ETDEWEB)

The Winter Fuels Report is intended to provide concise, timely information to the industry, the press, policymakers, consumers, analysts, and state and local governments on the following topics: distillate fuel oil net production, imports and stocks for all PADD's and product supplied on a US level; propane net production, imports and stocks for Petroleum Administration for Defense Districts (PADD) I, II, and III; natural gas supply and disposition, underground storage, and consumption for all PADD's; residential and wholesale pricing data for propane and heating oil for those states participating in the joint Energy Information Administration (EIA)/State Heating Oil and Propane Program; crude oil price comparisons for the United States and selected cities; and US total heating degree-days by city. This report will be published weekly by the EIA starting the first week in October 1990 and will continue until the first week in April 1991. The data will also be available electronically after 5:00 p.m. on Thursday during the heating season through the EIA Electronic Publication System (EPUB). 12 tabs.

1990-10-04

177

"Winter is coming"  

CERN Document Server

Those that do not sow care little about such mundane things as equinoxes or planting seasons, or even crop rotation for that matter. Wherever and whenever the reavers reave, the mood is always foul and the nights are never warm or pleasant. For the rest of the good folks of Westeros, however, a decent grasp of the long-term weather forecast is a necessity. Many a maester have tried to play the Game of Weather Patterns and foretell when to plant those last turnip seeds, hoping for a few more years of balmy respite. Tried and failed. For other than the somewhat vague (if not outright meaningless) omens of "Winter is Coming", their meteorological efforts have been worse than useless. To right that appalling wrong, here we attempt to explain the apparently erratic seasonal changes in the world of G.R.R.M. A natural explanation for such phenomena is the unique behavior of a circumbinary planet. Thus, by speculating that the planet under scrutiny is orbiting a pair of stars, we utilize the power of numerical three-...

Kostov, Veselin; Hartman, Nikolaus; Guzewich, Scott; Rogers, Justin

2013-01-01

178

Fallback foods of temperate-living primates: a case study on snub-nosed monkeys.  

Science.gov (United States)

Only a few primate species thrive in temperate regions characterized by relatively low temperature, low rainfall, low species diversity, high elevation, and especially an extended season of food scarcity during which they suffer from dietary stress. We present data of a case study of dietary strategies and fallback foods in snub-nosed monkeys (Rhinopithecus bieti) in the Samage Forest, Northwest Yunnan, PRC. The snub-nosed monkeys adjusted intake of plant food items corresponding with changes in the phenology of deciduous trees in the forest and specifically showed a strong preference for young leaves in spring. A non-plant food, lichens (Parmeliaceae), featured prominently in the diet throughout the year (annual representation in the diet was about 67%) and became the dominant food item in winter when palatable plant resources were scarce. Additional highly sought winter foods were frost-resistant fruits and winter buds of deciduous hardwoods. The snub-nosed monkeys' choice of lichens as a staple fallback food is likely because of their spatiotemporal consistency in occurrence, nutritional and energetic properties, and the ease with which they can be harvested. Using lichens is a way to mediate effects of seasonal dearth in palatable plant foods and ultimately a key survival strategy. The snub-nosed monkeys' fallback strategy affects various aspects of their biology, e.g., two- and three-dimensional range use and social organization. The higher abundance of lichens at higher altitudes explains the monkeys' tendency to occupy relatively high altitudes in winter despite the prevailing cold. As to social organization, the wide temporal and spatial availability of lichens strongly reduces the ecological costs of grouping, thus allowing for the formation of "super-groups." Usnea lichens, the snub-nosed monkeys' primary dietary component, are known to be highly susceptible to human-induced environmental changes such as air pollution, and a decline of this critical resource base could have devastating effects on the last remaining populations. Within the order Primates, lichenivory is a rare strategy and only found in a few species or populations inhabiting montane areas, i.e., Macaca sylvanus, Colobus angolensis, and Rhinopithecus roxellana. Other temperate-dwelling primates rely mainly on buds and bark as winter fallback foods. PMID:19890849

Grueter, Cyril C; Li, Dayong; Ren, Baoping; Wei, Fuwen; Xiang, Zuofu; van Schaik, Carel P

2009-12-01

179

Influence of temperate mixed and deciduous tree covers on Hg concentrations and photoredox transformations in snow  

Science.gov (United States)

Mercury dynamics in snowpacks under forested canopy are currently unknown, even though these snowpacks may represent important Hg pools eventually released towards lakes at snowmelt. We followed Hg distribution and partitioning in snowpacks under different temperate canopy types over space and time, and conducted short-term experiments on Hg redox behaviour in these snowpacks. Hg concentrations were ca. two times higher in snow deposited under coniferous than deciduous canopies; the lowest concentrations were observed in snow over a frozen lake in the same watershed. In snow on the ground, up to 80% of the Hg was bound to particles between 10 and 70 ?m. Incubations of snow in situ showed that (i) Hg photoreduction and evasion was significant in open areas (lake surface) but was greatly hampered by light attenuation under winter canopies and (ii) oxidation of newly produced Hg 0 was a significant process in boreal snow, affecting Hg evasion to the atmosphere. We used a mass balance approach to compare Hg pools in snowpacks with wet deposition measured by precipitation collectors. A net gain of Hg was observed in snow under mixed canopies whereas, under a deciduous canopy, the pool of Hg stored at the end of the winter was comparable to that of wet deposition. Snow over lake acted as a winter source of Hg. Whereas most Hg deposited by snow on lakes is lost before snowmelt, Hg deposited on the forested watershed is largely retained in snowpacks, presenting a threat to systems receiving meltwaters.

Poulain, Alexandre J.; Roy, Virginie; Amyot, Marc

2007-05-01

180

Ice-dependent winter survival of juvenile Atlantic salmon.  

Science.gov (United States)

Changes in snow and ice conditions are some of the most distinctive impacts of global warming in cold temperate and Arctic regions, altering the environment during a critical period for survival for most animals. Laboratories studies have suggested that reduced ice cover may reduce the survival of stream dwelling fishes in Northern environments. This, however, has not been empirically investigated in natural populations in large rivers. Here, we examine how the winter survival of juvenile Atlantic salmon in a large natural river, the River Alta (Norway, 70°N), is affected by the presence or absence of surface ice. Apparent survival rates for size classes corresponding to parr and presmolts were estimated using capture-mark-recapture and Cormack-Jolly-Seber models for an ice-covered and an ice-free site. Apparent survival (?) in the ice-covered site was greater than in the ice-free site, but did not depend on size class (0.64 for both parr and presmolt). In contrast, apparent survival in the ice-free site was lower for larger individuals (0.33) than smaller individuals (0.45). The over-winter decline in storage energy was greater for the ice-free site than the ice-covered site, suggesting that environmental conditions in the ice-free site caused a strong depletion in energy reserves likely affecting survival. Our findings highlight the importance of surface ice for the winter survival of juvenile fish, thus, underpinning that climate change, by reducing ice cover, may have a negative effect on the survival of fish adapted to ice-covered habitats during winter. PMID:23532172

Hedger, R D; Næsje, T F; Fiske, P; Ugedal, O; Finstad, A G; Thorstad, E B

2013-03-01

 
 
 
 
181

Ice-dependent winter survival of juvenile Atlantic salmon  

Science.gov (United States)

Changes in snow and ice conditions are some of the most distinctive impacts of global warming in cold temperate and Arctic regions, altering the environment during a critical period for survival for most animals. Laboratories studies have suggested that reduced ice cover may reduce the survival of stream dwelling fishes in Northern environments. This, however, has not been empirically investigated in natural populations in large rivers. Here, we examine how the winter survival of juvenile Atlantic salmon in a large natural river, the River Alta (Norway, 70°N), is affected by the presence or absence of surface ice. Apparent survival rates for size classes corresponding to parr and presmolts were estimated using capture-mark-recapture and Cormack-Jolly-Seber models for an ice-covered and an ice-free site. Apparent survival (?) in the ice-covered site was greater than in the ice-free site, but did not depend on size class (0.64 for both parr and presmolt). In contrast, apparent survival in the ice-free site was lower for larger individuals (0.33) than smaller individuals (0.45). The over-winter decline in storage energy was greater for the ice-free site than the ice-covered site, suggesting that environmental conditions in the ice-free site caused a strong depletion in energy reserves likely affecting survival. Our findings highlight the importance of surface ice for the winter survival of juvenile fish, thus, underpinning that climate change, by reducing ice cover, may have a negative effect on the survival of fish adapted to ice-covered habitats during winter.

Hedger, R D; Naesje, T F; Fiske, P; Ugedal, O; Finstad, A G; Thorstad, E B

2013-01-01

182

Parallel tempering in full QCD with Wilson fermions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We study the performance of QCD simulations with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering on $10^4$ and $12^4$ lattices. In order to compare tempered with standard simulations, covariance matrices between sub-ensembles have to be formulated and evaluated using the general properties of autocorrelations of the parallel tempering algorithm. We find that rendering the hopping parameter $\\kappa$ dynamical does not lead to an...

Ilgenfritz, E. -m; Kerler, W.; Muller-preussker, M.; Stuben, H.

2001-01-01

183

Convolution of n-dimensional Tempered Ultradistributions and Field Theory  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this work, a general definition of convolution between two arbitrary Tempered Ultradistributions is given. When one of the Tempered Ultradistributions is rapidly decreasing this definition coincides with the definition of J. Sebastiao e Silva. In the four-dimensional case, when the Tempered Ultradistributions are even in the variables $k^0$ and $\\rho$ (see Section 5) we obtain an expression for the convolution, which is more suitable for practical applications. The produc...

Bollini, C. G.; Rocca, M. C.

2003-01-01

184

Platonic temperance : the heart of a healthy constitution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Plato's notion of temperance, as elaborated in his dialogues the Republic and the Laws, is far removed from conventional modern thinking on the subject. Platonic temperance is as much a public as a private virtue. lts manifold meanings include restraint, moderation, order, equilibrium, harmony, measure, selfcontrol and balance. Temperance in one or other of these senses underpins a number of key concepts which lie at the heart of modern constitutional theory and practice. These are the ...

Domanski, A.; South African Society for Greek Philosophy and the Humanities

2003-01-01

185

Why bacteria are smaller in the epilimnion than in the hypolimnion? A hypothesis comparing temperate and tropical lakes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Bacterial size and morphology are controlled by several factors including predation, viral lysis, UV radiation, and inorganic nutrients. We observed that bacterial biovolume from the hypolimnion of two oligotrophic lakes is larger than that of bacteria living in the layer from surface to 20 m, roughly corresponding to the euphotic/epilimnetic zone. One lake is located in the temperate region at low altitude (Lake Maggiore, Northern Italy) and the other in the tropical region at high altitude ...

Salvador Hernandez-aviles, J.; Roberto Bertoni; Miroslav Macek; Cristiana Callieri

2012-01-01

186

Winter, Your Car, and You  

Science.gov (United States)

... channel, or forecasts in the daily papers. Your Car Prepare your car for winter. Start with a checkup that includes: • ... Checking antifreeze level and the freeze line. Your car should have a tune-up (check the owner's ...

187

Learners in Action, Winter 2005  

Science.gov (United States)

This Winter 2005 issue of "Learners in Action" contains the following: (1) Proud Dad Turns Family Life Around (Nick Prince); (2) Learners Make a Great Impression at Conference; (3) The Story behind the Story; and (4) Learner Resources.

Movement for Canadian Literacy, 2005

2005-01-01

188

CO2 flux in a cool-temperate deciduous forest (Quercus mongolica) of Mt. Nam in Seoul, Korea  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The Namsan Ecological Tower Site based on a flux tower was equipped with eddy covariance and automatic opening/closing chamber systems to collect long-term continuous measurements of CO2 flux, such as the net ecosystem exchange(NEE) and soil CO2 efflux in a cool-temperate Quercus mongolica forest. The mean concentrations of atmosphericCO2 (705 mg/m3) during the summer were smaller than those measured (770 mg/m3) during the winter. The mean CO2flux during the summer period was negative (-0.34 ...

2011-01-01

189

Zooplankton data report: Winter MIZEX, 1987  

Energy Technology Data Exchange (ETDEWEB)

The Marginal Ice Zone Experiment (MIZEX) was an interdisciplinary, international Arctic research program designed to study the atmospheric, oceanic, and ice interactions in the Fram Strait region of the Greenland Sea. This report focuses on zooplankton data collected during the winter MIZEX program of 1987. The primary objectives of our group during MIZEX 87 were to study the distribution of zooplankton species in relation to the ice-edge, the Polar Front, and the mesoscale eddy field, and to study zooplanktonic physiology just prior to the spring phytoplankton bloom. The data in this report are quantitative analyses of zooplankton samples collected while aboard the research vessel HAKON MOSBY during MIZEX 87. This is the third in a series of data reports on zooplankton collected in the Fram Strait region during the MIZEX project. A complete catalog of the reports generated from the MIZEX program is archived at the National Snow and Ice Data Center in Boulder, Colorado, USA. 1 ref., 3 tabs.

Smith, S.L.; Lane, P.V.Z.; Schwartling, E.M.; Beck, B.

1988-12-01

190

ACHIEVEMENTS IF WINTER PEA BREEDING ?????????? ? ???????? ????????? ??????  

Directory of Open Access Journals (Sweden)

Full Text Available Winter pea is being bred at Krasnodar in the Research Institute of Agriculture of the Russian Academy of Agricultural Sciences. An alternative pea variety Legion has been bred and included into the National List of Varieties. The article presents the description of the first winter leafless pea varieties - Zimus and Fokus, which have been passed to the National Variety Testing System in 2011

Brezhneva V. I.

2012-04-01

191

Resource use and consumption of three-spined sticklebacks (Gasterosteus aculeatus) under different environmental conditions during winter.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In temperate climate with pronounced seasonality, ice and snow cover reduces light conditions during winter which in turn reduce search efficiency for visual feeding consumers like fish. Furthermore, a suggested major effect of future climate change is an increased input of allochtonous DOC to aquatic systems which causes an increased brownification and hence reduced overall light conditions. In this study, I sampled YOY three-spined sticklebacks (Gasterosteus aculeatus) of different sizes ov...

Bystedt, David

2013-01-01

192

Asymptotic hyperfunctions, tempered hyperfunctions, and asymptotic expansions  

Directory of Open Access Journals (Sweden)

Full Text Available We introduce new subclasses of Fourier hyperfunctions of mixed type, satisfying polynomial growth conditions at infinity, and develop their sheaf and duality theory. We use Fourier transformation and duality to examine relations of these asymptotic and tempered hyperfunctions to known classes of test functions and distributions, especially the Gel'fand-Shilov spaces. Further it is shown that the asymptotic hyperfunctions, which decay faster than any negative power, are precisely the class that allows asymptotic expansions at infinity. These asymptotic expansions are carried over to the higher-dimensional case by applying the Radon transformation for hyperfunctions.

Andreas U. Schmidt

2005-05-01

193

Biodiversity of Chironomidae at the North Temperate Lakes LTER Site  

Science.gov (United States)

The National Science Foundation has established a network of Long Term Ecological Research (LTER) sites to enhance research at large spatial scales, extended temporal scales, and to facilitate intersite comparisons of system structure and processes. Present knowledge of Chironomidae community structure at LTER sites is insufficient to accomplish these goals. Our project objectives are to determine species composition of Chironomidae in a wide variety of aquatic habitats at LTERs, describe all undescribed species/life stage associations, determine the temporal seasonality of emergence and develop a data base of species by habitat and emergence times. Our methods include light trapping and sweep netting for adults, dip-netting and hand-picking wood/aquatic vegetation for larvae, collecting surface-floating pupal exuviae, and rearing to associate life stages. Our initial focus on the North Temperate Lakes LTER in Wisconsin and has documented 80 genera (representing > 125 species, including 18 undescribed species and/or unknown life stages) from 11 lakes, 5 streams and 2 bogs. Taxa include species with larvae that are: epiphytic, endophytic, xylophagic, phoretic on mollusks or other aquatic insects, specialized to feed on freshwater sponges, predators of black fly pupae, and those occurring in hyporheic zones, marginal semi-aquatic habitats or terrestrial soils.

Berg, M. B.; Olson, S.; Hayford, B.; Gresens, S. E.; Kennedy, J.; Bouchard, R. W.; Ferrington, L. C.

2005-05-01

194

Drought-deciduous behavior reduces nutrient losses from temperate deciduous trees under severe drought.  

Science.gov (United States)

Nutrient resorption from senescing leaves is an important mechanism of nutrient conservation in temperate deciduous forests. Resorption, however, may be curtailed by climatic events that cause rapid leaf death, such as severe drought, which has been projected to double by the year 2100 in the eastern United States. During a record drought in the southeastern US, we studied 18 common temperate winter-deciduous trees and shrubs to understand how extreme drought affects nutrient resorption of the macronutrients N, P, K, and Ca. Four species exhibited drought-induced leaf senescence and maintained higher leaf water potentials than the remaining 14 species (here called drought-evergreen species). This strategy prevented extensive leaf desiccation during the drought and successfully averted large nutrient losses caused by leaf desiccation. These four drought-deciduous species were also able to resorb N, P, and K from drought-senesced leaves, whereas drought-evergreen species did not resorb any nutrients from leaves lost to desiccation during the drought. For Oxydendrum arboreum, the species most severely affected by the drought, our results indicate that trees lost 50% more N and P due to desiccation than would have been lost from fall senescence alone. For all drought-deciduous species, resorption of N and P in fall-senesced leaves was highly proficient, whereas resorption was incomplete for drought-evergreen species. The lower seasonal nutrient losses of drought-deciduous species may give them a competitive advantage over drought-evergreen species in the years following the drought, thereby impacting species composition in temperate deciduous forests in the future. PMID:20364272

Marchin, Renée; Zeng, Hainian; Hoffmann, William

2010-08-01

195

Symbiodinium clade C dominates zooxanthellate corals (Scleractinia) in the temperate region of Japan.  

Science.gov (United States)

Endosymbiotic algae of the genus Symbiodinium have been divided into nine clades (A-I) following genetic classification; some clades are known to have physiological properties that enable the coral hosts to adapt to different environmental conditions. To understand the relationships of coral-alga symbioses, we focused on Symbiodinium diversity in zooxanthellate corals living under the severe environmental conditions of the temperate region (30°-35°N) of Japan. We investigated Symbiodinium clades in 346 colonies belonging to 58 coral species from six locations. We then selected three coral species-Acropora hyacinthus, Acropora japonica, and Cyphastrea chalcidicum-to investigate whether Symbiodinium clades changed during winter or summer over the course of year (May 2009-Apr 2010) in Tanabe Bay, Japan. Three Symbiodinium clades (C, D, and F) were detected in corals in the temperate region. Notably, 56 coral species contained Symbiodinium clade C. Oulastrea crispata predominantly contained clade D, but traces of clade C were also detected in all samples. The temperate-specific species Alveopora japonica contained clades C and F simultaneously. Seasonal change of symbiont clades did not occur in the three coral species during the investigation period where SSTs range on 12.5-29.2°C. However, we found Acropora (2 spp.) and Cyphastrea (1 sp.) contained different subcladal types of clade C. These results reveal that most coral species harbored Symbiodinium clade C stably throughout the year, suggesting that Symbiodinium clade C shows low-temperature tolerance, and that two hypothetical possibilities; genetic differences of subcladal types generating physiological differences or wide physiological flexibility in the clade C. PMID:22379984

Lien, Yi-Ting; Fukami, Hironobu; Yamashita, Yoh

2012-03-01

196

High order schemes for the tempered fractional diffusion equations  

CERN Document Server

L\\'{e}vy flight models whose jumps have infinite moments are mathematically used to describe the superdiffusion in complex systems. Exponentially tempering the probability of large jumps of L\\'{e}vy flights leads to the tempered stable L\\'{e}vy processes which combine both the $\\alpha$-stable and Gaussian trends; and the very large jumps are unlikely and all their moments exist. The probability density functions of the tempered stable L\\'{e}vy processes solve the tempered fractional diffusion equation. This paper focuses on designing the high order difference schemes for the tempered fractional diffusion equation on bounded domain. The high order difference approximations, called the tempered and weighted and shifted Gr\\"{u}nwald difference (tempered-WSGD) operators, in space are obtained by using the properties of the tempered fractional calculus and weighting and shifting their first order Gr\\"{u}nwald type difference approximations. And the Crank-Nicolson discretization is used in the time direction. The s...

Li, Can

2014-01-01

197

Examination of carbon partitioning into austenite during tempering of bainite  

International Nuclear Information System (INIS)

The redistribution of carbon after tempering of a novel nanocrystalline bainitic steel consisting of a mixture of supersaturated ferrite and retained austenite has been analyzed by atom probe tomography. No direct evidence supporting the additional carbon enrichment of austenite beyond that initially achieved during the bainite heat treatment was obtained during subsequent tempering of this high carbon, high silicon steel.

2010-08-01

198

Limit Theorems For Sequences of Tempered Stable and Related Distributions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this paper we define the closure under weak convergence of the class of p-tempered {\\alpha}-stable distributions. We give necessary and sufficient conditions for convergence of sequences in this class. Moreover, we show that any element in this class can be approximated by the distribution of a linear combination of elementary p-tempered {\\alpha}-stable random variables.

Grabchak, Michael

2012-01-01

199

Hysteresis conditions the vertical position of deep chlorophyll maximum in the temperate ocean  

Science.gov (United States)

chlorophyll maxima (DCMs) are widespread features of oceans. In temperate regions, DCMs are commonly associated with isopycnal surfaces that frequently move over a wide vertical range. This general association between DCMs and isopycnals remains unexplained by present theories, and we show here that it emerges from the seasonal history of the water column. Analysis of the formation of more than 9000 seasonal DCMs throughout the world's oceans consistently locates the vertical position of spring/summer DCMs in temperate seas at the density of the previous winter mixed layer, independently of this density value and future depth. These results indicate that DCM formation cannot be understood without hysteresis by solely considering the instantaneous response of phytoplankton to vertical gradients in physical and chemical fields. Present theories for DCM formation cannot explain why spring and summer DCMs are systematically found at a density equal to that of the previous mixed layer where a bloom has occurred. Rather than reacting to instantaneous physical forcing, the results indicate that DCMs operate as self-preserving biological structures that are associated with particular isopycnals because of their capacity to modify the physicochemical environment. Combined with remote sensors to measure salinity and temperature in the surface ocean, this new understanding of DCM dynamics has the potential to improve the quantification of three-dimensional primary production via satellites. This significant enhancement of the representation of oceanic biological processes can also allow increasingly realistic predictions of future biogeochemical scenarios in a warming ocean.

Navarro, Gabriel; Ruiz, Javier

2013-12-01

200

Energy and mass balance at the snow surface on a warm temperate mountain  

Science.gov (United States)

Snowmelt is an important water source in warm temperate mountains, where natural fresh water sources are often scarce, and vapor losses from the snow-surface can greatly limit water availability. Therefore, understanding of key processes of snow dynamics in such environment is highly important. To achieve this end, we estimated the energy and mass balance of the snowpack on Mt. Hermon, Israel (35o50'E, 33o25'N), using a snow model. The forcing variables for the simulations were collected in two meteorological stations located along altitudinal gradient at 1,640 and 1,960m. We simulated the snowpack energy and mass balance during the winter of 2010/11 in a Deep Snowpack (DSP; maximum depth of 7m), and in a karstic depression known as the 'Bulan', where both windswept locations and lee-side (DSP) locations were simulated. The calibration of the model for the DSP was done using snow water equivalent (SWE) data, collected by snow-surveys. The simulation of the Bulan was calibrated against melting cycles that were measured with time-lapse cameras. Using a step function to describe wind speed over the DSP we showed that the turbulent fluxes were influenced by changes in snowpack height. The turbulent fluxes were the dominant ones at the snow surface on this warm temperate mountain site. During winter time, vapor losses varied between 46 to 82 % of the total ablation. Consequently, latent heat flux consumed much of the available energy at the snow-surface, greatly limiting melting rate to 1 mm day-1. During spring time, vapor flux was positive, enhancing condensation and resulting in an average melting flux of 86 mm day-1. The simulation of the 'Bulan' showed that the variation in the vapor flux with time created a variation in space of the available water at the bottom of the snowpack.

Sade, Rotem; Rimmer, Alon; (Iggy) Litaor, Michael; Furman, Alex

2014-05-01

 
 
 
 
201

New methods for improving winter road maintenence  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Winter road maintenance activities are crucial for maintaining the accessibility and traffic safety of the road network during winters. Common winter road maintenance activities include plowing and the use of de-icing agents (e.g. NaCl) to avoid freezing. Effective winter road maintenance strives towards keeping the roads free from snow and ice while reducing negative side effects of winter road maintenance, such as ground water contamination from road salt. Since the weather is decisive for ...

Riehm, Mats

2010-01-01

202

A Third Way for Entomophthoralean Fungi to Survive the Winter: Slow Disease Transmission between Individuals of the Hibernating Host  

Directory of Open Access Journals (Sweden)

Full Text Available In temperate regions, insect pathogenic fungi face the challenge of surviving through the winter. Winter is a time when hosts are immobile, low in number or are present in a stage which is not susceptible to infection. Fungi from Entomophthoromycota have so far been known to survive the winter in two ways: either as (1 thick-walled resting spores released into environment from dead hosts, or as (2 structures inside the dead host (e.g., hyphal bodies. Here we report, from the Danish environment, a third way to survive the winter, namely a slow progression and transmission of Entomophthora schizophorae in adult dipteran Pollenia hosts that hibernate in clusters in unheated attics, sheltered areas outdoors (under bark etc.. Fungus-killed sporulating flies were observed outside very early and very late in the season. By sampling adults at the time of their emergence from hibernation in late winter/early spring we documented that the fungus was naturally prevalent and killed flies after a period of incubation. Experimentally we documented that even at the low temperature of 5 °C, the fungus was able to maintain itself in Pollenia cohorts for up to 90 days. From these observations the full winter cycle of this fungus is elucidated. The three types of winter survival are discussed in relation to fungus epidemic development.

Annette Bruun Jensen

2013-07-01

203

Four-year measurement of methane flux over a temperate forest with a relaxed eddy accumulation method  

Science.gov (United States)

Forests are generally assumed to be an atmospheric methane (CH4) sink (Le Mer and Roger, 2001). However, under Asian monsoon climate, forests are subject to wide spatiotemporal range in soil water status, where forest soils often became water-saturated condition heterogeneously. In such warm and humid conditions, forests may act as a CH4 source and/or sink with considerable spatiotemporal variations. Micrometeorological methods such as eddy covariance (EC) method continuously measure spatially-representative flux at a canopy scale without artificial disturbance. In this study, we measured CH4 fluxes over a temperate forest during four-year period using a CH4 analyzer based on tunable diode laser spectroscopy detection with a relaxed eddy accumulation (REA) method (Hamotani et al., 1996, 2001). We revealed the amplitude and seasonal variations of canopy-scale CH4 fluxes. The REA method is the attractive alternative to the EC method to measure trace-gas flux because it allows the use of analyzers with an optimal integration time. We also conducted continuous chamber measurements on forest floor to reveal spatial variations in soil CH4 fluxes and its controlling processes. The observations were made in an evergreen coniferous forest in central Japan. The site has a warm temperate monsoon climate with wet summer. Some wetlands were located in riparian zones along streams within the flux footprint area. For the REA method, the sonic anemometer (SAT-550, Kaijo) was mounted on top of the 29-m-tall tower and air was sampled from just below the sonic anemometer to reservoirs according to the direction of vertical wind velocity (w). After accumulating air for 30 minutes, the air in the reservoirs was pulled into a CO2/H2O gas analyzer (LI-840, Li-Cor) and a CH4 analyzer (FMA-200, Los Gatos Research). Before entering the analyzers, the sampled air was dried using a gas dryer (PD-50 T-48; Perma Pure Inc.). The REA flux is obtained from the difference in the mean concentrations of the reservoirs. In the chamber method, automated dynamic-closed chambers were located at three points of water-unsaturated forest floor. Soil CO2 and CH4 fluxes were measured using the same analyzers with the REA method. CH4 fluxes showed seasonal variations at both canopy and plot scales. Based on the chamber measurements, water-unsaturated forest floor mostly consumed CH4 throughout a year. In contrast, canopy-scale CH4 fluxes by the REA method seasonally fluctuated between emission and absorption. The seasonal variation of canopy-scale CH4 fluxes varied at years to years. Every year, no notable emission nor absorption was observed during winter when daily average air temperature was less than about 10°C. In this forest, the canopy-scale CH4 fluxes could be determined by a balance between sources by methanogens and sinks by methanotrophs. Since these two processes were influenced by soil conditions (e.g., soil temperature and soil moisture), canopy-scale CH4 fluxes were influenced by CH4 fluxes from wetlands within the forest, because magnitude of wetland emission was a few order larger than those of absorption. We will discuss the factors of interannual variation of the canopy- and plot-scale CH4 fluxes in terms of precipitation patterns.

Sakabe, A.; Kosugi, Y.; Ueyama, M.; Hamotani, K.; Takahashi, K.; Iwata, H.; Itoh, M.

2013-12-01

204

Temperate Ice Depth-Sounding Radar  

Science.gov (United States)

Glaciers in several parts of the world are reported to be retreating and thinning rapidly over the last decade. Radar instruments can be used to provide a wealth of information regarding the internal and basal conditions of large and small ice masses. These instruments typically operate in the VHF and UHF regions of the electromagnetic spectrum. For temperate-ice sounding, however, the high water content produces scattering and attenuation in propagating radar waves at VHF and UHF frequencies, which significantly reduce the penetration depths. Radars operating in the HF band are better suited for systematic surveys of the thickness and sub-glacial topography of temperate-ice regions. We are developing a dual-frequency Temperate-Ice-Depth Sounding Radar (TIDSoR) that can penetrate through water pockets, thus providing more accurate measurements of temperate ice properties such as thickness and basal conditions. The radar is a light-weight, low power consumption portable system for surface-based observations in mountainous terrain or aerial surveys. TIDSoR operates at two different center frequencies: 7.7 MHz and 14 MHz, with a maximum output peak power of 20 W. The transmit waveform is a digitally generated linear frequency-modulated chirp with 1 MHz bandwidth. The radar can be installed on aircrafts such as the CReSIS UAV [1], DCH-6 (Twin Otter), or P-3 Orion for aerial surveys, where it could be supported by the airplane power system. For surface based experiments, TIDSoR can operate in a backpack configuration powered by a compact battery system. The system can also be installed on a sled towed by a motorized vehicle, in which case the power supply can be replaced by a diesel generator. The radar consists of three functional blocks: the digital section, the radio-frequency (RF) section, and the antenna, and is designed to weigh less than 2 kg, excluding the power supply. The digital section generates the transmit waveforms as well as timing and control signals. It also digitizes the output signal from the receiver and stores the data in binary format using a portable computer. The RF-section consists of a high- power transmitter and a low-noise receiver with digitally controlled variable gain. The antenna is time-shared between the transmitter and receiver by means of a transmit/receive (T/R) switch. In regards to the antenna, we have made a survey study of various electrically small antennas (ESA) to choose the most suitable radiating structure for this application. Among the different alternatives that provide a good trade-off between electrical performance and small size, we have adopted an ESA dipole configuration for airborne platforms and a half-wavelength radiator for the surface-based version. The airborne antenna solution is given after studying the geometry of the aerial vehicle and its fuselage contribution to the antenna radiation pattern. Dipoles are made of 11.6 mm diameter cables (AWG 0000) or printed patches embedded into the aircraft fuselage, wings, or both. The system is currently being integrated and tested. TIDSoR is expected to be deployed during the spring 2008 either in Alaska or Greenland for surface based observations. In this paper, we will discuss our design considerations and current progress towards the development of this radar system. [1] Center for Remote Sensing of Ice Sheets (Cresis), Sept 2008, [Online]. Available: http://www.cresis.ku.edu

Jara-Olivares, V. A.; Player, K.; Rodriguez-Morales, F.; Gogineni, P.

2008-12-01

205

Parallel tempering Monte Carlo in LAMMPS.  

Energy Technology Data Exchange (ETDEWEB)

We present here the details of the implementation of the parallel tempering Monte Carlo technique into a LAMMPS, a heavily used massively parallel molecular dynamics code at Sandia. This technique allows for many replicas of a system to be run at different simulation temperatures. At various points in the simulation, configurations can be swapped between different temperature environments and then continued. This allows for large regions of energy space to be sampled very quickly, and allows for minimum energy configurations to emerge in very complex systems, such as large biomolecular systems. By including this algorithm into an existing code, we immediately gain all of the previous work that had been put into LAMMPS, and allow this technique to quickly be available to the entire Sandia and international LAMMPS community. Finally, we present an example of this code applied to folding a small protein.

Rintoul, Mark Daniel; Plimpton, Steven James; Sears, Mark P.

2003-11-01

206

Raising the temper-mu-spot analysis of temper inclusions in experimental ceramics  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Provenancing of ancient ceramics is a highly important scientific tool for archaeological studies. In general, ceramics are not made from the original clay as it is found in deposits. To produce the needed physical properties in the finished product, the clay has to be either tempered by adding sands or biological materials, or levigated, to remove the coarse fraction. Thus, the chemical composition of the finished ceramic differs from the composition of the original clay bed. To overcome thi...

2012-01-01

207

A Parallel Tempering algorithm for probabilistic sampling and multimodal optimization  

Science.gov (United States)

Non-linear inverse problems in the geosciences often involve probabilistic sampling of multimodal density functions or global optimization and sometimes both. Efficient algorithmic tools for carrying out sampling or optimization in challenging cases are of major interest. Here results are presented of some numerical experiments with a technique, known as Parallel Tempering, which originated in the field of computational statistics but is finding increasing numbers of applications in fields ranging from Chemical Physics to Astronomy. To date, experience in use of Parallel Tempering within earth sciences problems is very limited. In this paper, we describe Parallel Tempering and compare it to related methods of Simulated Annealing and Simulated Tempering for optimization and sampling, respectively. A key feature of Parallel Tempering is that it satisfies the detailed balance condition required for convergence of Markov chain Monte Carlo (McMC) algorithms while improving the efficiency of probabilistic sampling. Numerical results are presented on use of Parallel Tempering for trans-dimensional inversion of synthetic seismic receiver functions and also the simultaneous fitting of multiple receiver functions using global optimization. These suggest that its use can significantly accelerate sampling algorithms and improve exploration of parameter space in optimization. Parallel Tempering is a meta-algorithm which may be used together with many existing McMC sampling and direct search optimization techniques. It's generality and demonstrated performance suggests that there is significant potential for applications to both sampling and optimization problems in the geosciences.

Sambridge, Malcolm

2014-01-01

208

wildlife in autumn and winter  

Wildlife in Autumn and Winter Roe Valley Country Park Resource Book for Key Stage 2 Pupils Roe Valley Country Park www.ehsni.gov.uk 1 Introduction This booklet has been prepared for use as notes for teachers of KS2 ...

209

Learners in Action, Winter 2006  

Science.gov (United States)

This Winter 2006 issue of "Learners in Action" contains the following articles: (1) Premiers Honour Adult Learners; (2) Learning Difficulties?; (3) Awards; (4) Hats off to Jacques Demers!; (5) What Do You Think?; (6) Meet the Current Learners Advisory Network; and (7) "Learning Edge" is No Ordinary Magazine!.

Movement for Canadian Literacy, 2006

2006-01-01

210

Non destructive evaluation of temper embrittlement of martensitic stainless steel  

International Nuclear Information System (INIS)

Martensitic stainless steel SS403, a sub set of SS410, is widely used as fuel-channel end-fitting material in Pressurized Heavy Water Reactor (PHWR). This material is selected because of its high corrosion resistance (the design utilizes several critical seal faces), good mechanical properties (optimum combination of strength, toughness and hardness for leak- tight roll joint), matching thermal coefficient of expansion with zirconium alloys (to minimize thermal stresses at rolled joint) and resistance to irradiation induced damages .The steel is produced by the electric arc furnace process and is subjected to vacuum degassing and electro-slag refining (ESR). The material is used in quenched and tempered condition. The end product should have at least 27 J minimum (Longitudinal) Charpy V-Notch (CVN) impact value at 21 deg C and 20J minimum (Transverse) CVN impact value at 65 deg C. In Martensitic Stainless Steel, a wide range of mechanical properties can be obtained by varying the tempering temperature and time . As tempering temperature is increased or time at particular temperature is prolonged, tensile strength, yield strength and hardness decrease; and impact strength, elongation, and reduction in area increase. The most uniform hardness is attained by close control of temperature, especially when tempering at lower temperatures. The tempering temperature depends primarily on the properties desired. Like most alloy steels, the hardenable stainless steels also develop lower impact strength when tempered in the range from about 250 deg C to 550 deg C. Tempering at lower side of the range results in tempered martensite embrittlement (TME) whereas aging at temperature near 450-550 deg C results in temper embrittlement (TE). Temper embrittlement is caused by segregation of impurity elements mainly S, P. Si, Sn, As, Sb, and P at prior austenite grain boundaries. Under loading it causes de-cohesion along the grain boundaries leading to intergranular failure. Whereas TME is not related to the segregation phenomena and failure is transgranular with respect to prior austenite grain boundary. Magnitude of embrittlement is significantly greater in material which contain higher amount of retained austenite. Explanations of TME are linked to the coarsening of inter-lath cementite formed from decomposition of retained austenite during tempering. The embrittlement manifests as degradation in CVN impact properties namely viz, reduction in upper shelf energy (USE) or increase in ductile-brittle transition temperature (DBTT). As a result, tempering of this steel is generally confined to the range of 590 deg C to 750 deg C. (author)

2009-11-01

211

Examination of carbon partitioning into austenite during tempering of bainite  

Energy Technology Data Exchange (ETDEWEB)

The redistribution of carbon after tempering of a novel nanocrystalline bainitic steel consisting of a mixture of supersaturated ferrite and retained austenite, has been analyzed by atom probe tomography. Direct supporting evidence of additional austenite carbon enrichment beyond that initially achieved during the bainite heat treatment was not obtained during subsequent tempering of this high carbon, high silicon steel. Evidence of competing reactions during tempering, such as the formation of carbon clusters in bainitic ferrite that signify the onset of the transitional carbides precipitation, was observed.

Clarke, Amy J [Los Alamos National Laboratory; Caballero, Francisca G [CENIM-CSIC, MADRIS, SPAIN; Miller, Michael K [ORNL; Garcia - Mateo, C [CENIM-CSIC, MADRID, SPAIN

2010-01-01

212

Magnetic nondestructive technology for detection of tempered martensite embrittlement  

International Nuclear Information System (INIS)

A nondestructive eddy current technique is used to evaluate tempered martensite embrittlement in 4340 AISI steels after quench and tempering in the range 240–550 °C. A relation between the responses of the magnetic induction (normalized impedance of the coil) and destructive Charpy impact test results has been established. The study shows that the eddy current method could be used to separate brittle parts due to the microstructure changes. - Highlights: ? Occurrence of tempered martensite embrittlement in 4340 AISI steels was evaluated. ? A reliable relation between EC output and Charpy impact test results was obtained. ? EC technique was used to separate brittle parts due to the microstructure changes.

2012-11-01

213

THE SILICON EFFECT IN THE TEMPERING OF MARTENSITE IN STEELS  

Digital Repository Infrastructure Vision for European Research (DRIVER)

High-silicon steels have long been known to possess exceptional resistance to tempering, but the reasons for this effect were unknown. We report here a study of the third stage of tempering of these steels, in which cementite is formed. In a 0.75 wt% C - 1.4 wt% Si alloy steel, tempered for 1 hour at 380°C, it is found that silicon atoms are rejected from the growing cementite into the ferrite matrix, and form a silicon-enriched atmosphere around the particles. The concentration of silicon i...

Chang, Li; Smith, G.

1984-01-01

214

Neural network prediction of hardness in HAZ of temper bead welding using the proposed thermal cycle tempering parameter (TCTP)  

International Nuclear Information System (INIS)

A new thermal cycle tempering parameter (TCTP) to characterize the tempering effect during multi-pass thermal cycles has been proposed by extending the Larson-Miller parameter (LMP) to non-isothermal heat treatment. Experimental results revealed that the hardness in synthetic HAZ of low-alloy steel subjected to multi-pass tempering thermal cycles has a good linear relationship with the TCTP. The new hardness prediction system was constructed by using a neural network taking into consideration of the tempering effect during multi-pass welding, estimated by using the TCTP. Based on the thermal cycles numerically obtained by FEM and the experimentally obtained hardness database, the hardness distribution in HAZ of low-alloy steel welded with temper bead welding method was calculated. The predicted hardness was in good accordance with the experimental results. It follows that our new prediction system is effective for estimating the tempering effect in HAZ during multi-pass welding and hence enables us to assess the effectiveness of temper bead welding. (author)

2011-09-01

215

Characteristics of the rough-cut surface of quenched and tempered martensitic stainless steel using wire electrical discharge machining  

Science.gov (United States)

This article studies the surface characteristics of quench- and temper-treated AISI 440A martensitic stainless steels, which were rough cut using wire electrical discharge machining (WEDM). The microstructure of the recast layer on the cut surface was investigated using scanning and transmission electron microscopes, and the phase compositions were analyzed with an energy-dispersive X-ray (EDX) spectrometer. Experimental results showed that the thickness of the recast layer varied with the heat-treatment condition of the workpiece, the largest thickness was obtained with a quenched specimen, and the thickness decreased with increasing tempering temperature. Intergranular surface cracks were observed only from the as-quenched specimen, whereas surface cracks were not found in the rough-cut specimens after tempering above 200 °C. It is reckoned that reliefing of the thermal residual stress in the quenched workpiece induced the surface intergranular cracks. Microstructures of the recast layer on the rough-cut surfaces of the 600 °C tempered specimen were examined using cross-sectional transmission electron microscopy (TEM) specimens. An amorphous layer exists at some parts of the outermost cut surface. A high density of wire electrode droplets of spherical shape, approximately 10 to 60 nm in size, was found throughout the porous recast layer. Besides, many high-chromium containing sigma spheres with sizes of approximately 120 to 200 nm were precipitated at the bottom part of the recast layer, and its formation mechanism was proposed. Adjacent to the recast layer was a heat-affected zone (HAZ) with a thickness of about 4 µm, in which temper-induced carbides were fully dissolved. The HAZ comprised basically two distinct regions: the first region adjacent to the recast layer was composed of a lath martensite structure, while the other region was an annealed ferrite structure.

Huang, C. A.; Tu, G. C.; Yao, H. T.; Kuo, H. H.

2004-04-01

216

Hardness, Microstructure, and Residual Stresses in Low Carbon Steel Welding with Post-weld Heat Treatment and Temper Bead Welding  

Science.gov (United States)

This paper investigates the effects of post-weld heat treatment (PWHT) and temper bead welding (TBW) on hardness, microstructure and residual stresses in multi-layer welding on low carbon steel specimens made with two different weld geometries, viz. (1) smooth-contoured and (2) U-shaped. It was found that the PWHT technique gave overall lower hardness than the TBW technique, but the hardness values in both techniques were acceptable. Microscopy analysis showed that the TBW technique was more effective in tempering the heat affected zone as the grain size decreased slightly at the fusion line in spite of the higher temperature at the fusion line. Residual stresses measured using the hole-drilling method showed that the residual stress is not reduced below yield stress near the last bead solidified in TBW. Only PWHT gives low residual stress results in this area. High tensile residual stresses may result in sensitivity to fatigue loading.

Aloraier, Abdulkareem S.; Joshi, Suraj; Price, John W. H.; Alawadhi, Khaled

2014-04-01

217

Winter Operations-Abrasives and Salt Brine.  

Science.gov (United States)

The primary objective of winter maintenance operations is to improve traffic safety and efficiency during winter storm periods. Abrasives and salt brines have been successfully applied to increase traction and prevent snow and ice from bonding to road sur...

G. Pesti Y. Liu

2003-01-01

218

Human impacts: Winter weather and health  

Science.gov (United States)

There has been much debate about whether winter warming due to climate change will substantially decrease mortality in that season. Research now finds that cold severity no longer predicts the number of excess winter deaths in England and Wales.

Huang, Cunrui; Barnett, Adrian

2014-03-01

219

Ductile-Brittle Transition Behavior in Tempered Martensitic SA508 Gr. 4N Ni-Mo-Cr Low Alloy Steels for Reactor Pressure Vessels  

International Nuclear Information System (INIS)

Reactor pressure vessels (RPVs) operate under severe conditions of elevated temperature, high pressure, and irradiation. Therefore, a combination of sufficient strength, toughness, good weldability, and high irradiation resistance are required for RPV materials. SA508 Gr.4N low alloy steel, which has higher Ni and Cr contents than those of commercial RPV steel, Gr.3 steel, is considered as a candidate material due to its excellent mechanical properties from tempered martensitic microstructure. The ferritic steels such as Gr.3 and Gr.4N low alloy steels reveal a ductile-brittle transition and large scatters in the fracture toughness within a small temperature range. Recently, there are some observations of the steeper transition behavior in the tempered martensitic steels, such as Eurofer97 than the transition behavior of commercial RPV steels. It was also reported that the fracture toughness increased discontinuously when the phase fraction of the tempered martensite was over a critical fraction in the heat affected zones of SA508 Gr.3. Therefore, it may be necessary to evaluate the changes of transition behavior with a microstructure for the tempered martensitic SA508 Gr.4N low alloy steel. In this study, the fracture toughness for SA508 Gr.4N low alloy steels was evaluated from a view point of the temperature dependency with phase fraction of tempered martensite controlled by cooling rate. Additionally, a possible modification of the fracture toughness master curve was proposed and discussed

2010-05-01

220

On positivity in algebras of tempered generalized functions  

CERN Document Server

An explicit counterexample shows that contrary to the situation in the special Colombeau algebra, positivity and invertibility cannot be characterized pointwise in algebras of tempered generalized functions. Further a point value characterization of the latter is refined.

Mayerhofer, Eberhard

2008-01-01

 
 
 
 
221

Drilling in tempered glass â?? modelling and experiments  

DEFF Research Database (Denmark)

The present paper reports experimentally and numerically obtained results for the process of drilling in tempered glass. The experimental results are drilling depths on the edge in 19mm tempered glass with a known residual stress state measured by a scattered light polariscope. The experiments have been modelled using a state-of-the-art model and compared with satisfying result to the performed experiments. The numerical model has been used for a parametric study, investigating the redistribution of residual stresses during the process of drilling. This is done for investigating the possibility of applying forces in such holes and thereby being able to mechanically assemble tempered glass without the need of drilling holes before the tempering process. The paper is the result of currently ongoing research and the results should be treated as so.

Nielsen, Jens Henrik

222

Magnetic nondestructive technology for detection of tempered martensite embrittlement  

Science.gov (United States)

A nondestructive eddy current technique is used to evaluate tempered martensite embrittlement in 4340 AISI steels after quench and tempering in the range 240-550 °C. A relation between the responses of the magnetic induction (normalized impedance of the coil) and destructive Charpy impact test results has been established. The study shows that the eddy current method could be used to separate brittle parts due to the microstructure changes.

Kashefi, Mehrdad; Rafsanjani, Ali; Kahrobaee, Saeed; Alaee, Moeen

2012-11-01

223

Contribution to the modelling of chocolate tempering process.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The tempering of chocolate, i.e. the process of crystallization of the desired morph; is a key step in its manufacturing by professional chocolatiers. In this work, a model of a tempering process based on seeding with solid chocolate grains is developed to enhance understanding and control of the system. The model aims to predict temperature field during melting and crystallization of the product. Therefore a mechanical stirrer is designed to simulate the manual mixing. Resulting flow field i...

2007-01-01

224

Method for heating, forming and tempering a glass sheet  

Energy Technology Data Exchange (ETDEWEB)

A method for heating, forming and tempering a glass sheet including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet.

Boaz, Premakaran Tucker (Livonia, MI); Sitzman, Gary W. (Walled Lake, MI)

1998-01-01

225

Method for heating, forming and tempering a glass sheet  

Energy Technology Data Exchange (ETDEWEB)

A method for heating, forming and tempering a glass sheet is disclosed including the steps of heating at least one glass sheet to at least a first predetermined temperature, applying microwave energy to the glass sheet to heat the glass sheet to at least a second predetermined temperature, forming the glass sheet to a predetermined configuration, and cooling an outer surface of the glass sheet to at least a third predetermined temperature to temper the glass sheet. 2 figs.

Boaz, P.T.; Sitzman, G.W.

1998-10-27

226

Tempering and Annealing in a Verdier-Stockmayer Polymer  

Directory of Open Access Journals (Sweden)

Full Text Available Two Monte Carlo methods, simulated annealing and parallel tempering, were applied to a Verdier-Stockmayer polymer. The efficiency of the two algorithms in exploring the lowest energy state possible for the model polymers was measured by the number of energy-degenerate configurations (configurations that have the same energy but are structurally different. Parallel tempering consistently explored more energy-degenerate configurations as compared with simulated annealing.

E. R. Obias

2004-12-01

227

Significance of Rate of Work Hardening in Tempered Martensite Embrittlement  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The main explanations for tempered martensite embrittlement are based on the effects of impurities and cementite precipitation on the prior austenite grain boundaries. There are some studies where the rate of work hardening is proposed as a potential reason for the brittleness. One steel was studied by means of a specially developed precision torsional testing device. The test steel had a high Si and Ni content so ? carbide and Fe3C appear in quite different tempering temperature ranges. The...

Pietikainen, J.

1995-01-01

228

Computer simulation of quenched and tempered steel properties  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The algorithm of estimation of mechanical properties based on steel hardness has been established.Design/methodology/approach: Numerical modelling of hardness distribution in as-quenched steel specimen was performed by involving the results of simple experimental test, i.e., Jominy-test. Hardness of quenched and tempered steel has been expressed as function of maximal hardness of actual steel and hardness of actual steel with 50% of martensite in microstructure, according to the time and temperature of tempering. After that distribution of other relevant mechanical properties was predicted based on predicted as-quenched and tempered hardness of steel. Experimental investigation has been performed on low alloy steel. The established procedure for estimation of quenched and tempered properties of steel has been applied in computer simulation of mechanical properties of quenched and tempered steel workpiece of complex form.Findings: Algorithm of estimation of hardness of quenched and tempered steel was improved. It can be concluded that working stress of quenched and tempered shaft can be successfully predicted by proposed method. The proposed computer simulation method could be applied in failure prevention.Research limitations/implications: The research was focused only on carbon and low alloyed heat treatable steels.Practical implications: The established algorithms can be used for prediction of mechanical properties in heat treating practice. Estimation of as-quenched hardness distribution is based on time, relevant for structure transformation, i.e., time of cooling from 800 to 500°C (t8/5. The hardness in the quenched and tempered state is estimated from the as-quenched hardness. The prediction of yield strength and toughness of steel is based on steel hardness.Originality/value: Hardness distribution is predicted by involving the results of simple experimental test, i.e., Jominy-test in numerical modelling of steel quenching.

B. Smoljan

2011-06-01

229

Tempering and Annealing in a Verdier-Stockmayer Polymer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Two Monte Carlo methods, simulated annealing and parallel tempering, were applied to a Verdier-Stockmayer polymer. The efficiency of the two algorithms in exploring the lowest energy state possible for the model polymers was measured by the number of energy-degenerate configurations (configurations that have the same energy but are structurally different). Parallel tempering consistently explored more energy-degenerate configurations as compared with simulated annealing.

2004-01-01

230

Influence of tempering temperature on mechanical properties of cast steels  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents results of research on the influence of tempering temperature on structure and mechanical properties of bainite hardened cast steel: G21CrMoV4 – 6 (L21HMF and G17CrMoV5 – 10 (L17HMF. Investigated cast steels were taken out from internal frames of steam turbines serviced for long time at elevated temperatures. Tempering of the investigated cast steel was carried out within the temperature range of 690 ÷ 730 C (G21CrMoV4 – 6 and 700 ÷ 740 C (G17CrMoV5 – 10. After tempering the cast steels were characterized by a structure of tempered lower bainite with numerous precipitations of carbides. Performed research of mechanical properties has shown that high temperatures of tempering of bainitic structure do not cause decrease of mechanical properties beneath the required minimum.oo It has also been proved that high-temperature tempering (>720 oC ensures high impact energy at the 20% decrease of mechanical properties.

G. Gola?ski

2008-12-01

231

33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.  

Science.gov (United States)

... 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109...SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor Lobster Boat Race, Winter Harbor,...

2010-07-01

232

Does outdoor work during the winter season protect against depression and mood difficulties?  

DEFF Research Database (Denmark)

OBJECTIVE: At temperate latitudes, 1-5% of the population suffer from winter depression; during winter, mood difficulties tend to increase but may be alleviated by bright light therapy. Unlike indoor workers, outdoor workers are exposed to therapeutic levels of sunlight during winter. We hypothesized that outdoor work may protect against mood difficulties and depression. METHOD: We studied this hypothesis among 2910 civil servants from Ã?rhus, Denmark, who participated in a survey in January-February 2009. Mental symptoms (N=422) defined a common case category that we broke down into two parts: depression (N=66) and mood difficulties but no depression (N=356). A total of 222 controls were also sampled from the study population. All 644 participants reported the extent of outdoor work. RESULTS: The confounder-adjusted odds ratio (OR) of mood difficulties showed a decreasing trend by increasing hours of outdoor work of borderline statistical significance. The OR was 0.63 [95% confidence interval (95% CI) 0.34-1.18)] for those working outdoors for >2 hours a day. No such effect was suggested for depression. CONCLUSION: Our study is limited by its cross-sectional design and low statistical power but nevertheless suggests that outdoor work during winter may protect against mood difficulties. If this finding holds true it may have significant impact on workers' health as well as public health in general. Therefore, further studies are recommended.

Hahn, Ina H; Grynderup, Matias B

2011-01-01

233

Embrittlement of normalized and tempered 2.25Cr-1Mo steel by the temper embrittlement under stress  

International Nuclear Information System (INIS)

Due to the temper embrittlement, 2 1/4Cr-1Mo steel, normalized and tempered, becomes brittled in the temperature range of 400 - 550 C, although the material is one of the promising candidates for the Experimental Very High Temperature Gas Cooled Reactor (VHTR) pressure vessel. Effect of tensile stress on the temper embrittlement has been examined here for the normalized and tempered 2 1/4Cr-1Mo steel. The results of charpy impact tests indicated that the embrittlement, which was assessed in terms of 50 ft-1bf level transition temperature, became more pronounced with increase in the applied stress level. Scanning electron microscopic observations revealed that the increase in transition temperature was accompanied by the increase of intergranular fracture. Segregation of phosphorus at grain boundaries was found by Auger electron microscope. These results suggested that the segregation of phosphorus at grain boundaries was accelerated by the applied stress. (author)

1980-01-01

234

Strong seasonal effect of moderate experimental warming on plankton respiration in a temperate estuarine plankton community  

Science.gov (United States)

Climate change projections forecast a 1.1-6.4 °C global increase in surface water temperature and a 3 °C increase for the Baltic Sea. This study examined the short-term interactive effects of a realistic future temperature increase (3 °C) on pelagic respiration and bacterioplankton growth and phytoplankton photosynthesis in situ. This study was undertaken throughout a full seasonal cycle in the northern Baltic Sea. We found marked positive short-term effects of temperature on plankton respiration but no significant effect on bacterioplankton growth or phytoplankton photosynthesis. Absolute respiration rates remained similar to other comparable environments at the in situ temperature. With the 3 °C temperature increase, respiration rates in situ increased up to 5-fold during the winter and 2-fold during the summer. A maximum seasonal Q10 value of 332 was observed for respiration during the cold winter months (twater ? 0 °C), and summer Q10 values were comparatively high (9.1). Q10 values exhibited a significant inverse relationship to water temperature during winter. Our results thereby suggest that plankton respiration in this coastal zone is more temperature sensitive than previously reported. In addition, field data indicated that plankton respiration switched from being temperature limited to being limited by dissolved organic carbon (DOC) after the simulated temperature increase. Assuming that our observations are relevant over longer time scales, climate change may worsen hypoxia, increase CO2 emissions and create a more heterotrophic food web in coastal zones with a high load of riverine DOC.

Panigrahi, Satya; Nydahl, Anna; Anton, Peter; Wikner, Johan

2013-12-01

235

Relative Aerial Biomass Yield of Intercroped Alfalfa with Winter Forage Cereals Rendimiento Relativo de Biomasa Aérea en Intercultivos de Alfalfa con Cereales Forrajeros de Invierno  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In the tropical regions of the world, intercropping is mostly associated with food grain production, whereas it is receiving increased attention in temperate regions as a means of efficient forage production. The aim of this work was to determine the relative yield of aerial biomass in alfalfa or lucerne (Medicago sativa L.) and winter forage cereals intercrops. These were done in eight systems resulting from the combination of species sown at different dates. The biomass was measured in thre...

Telmo Pereyra; Héctor Pagliaricci; Alfredo Ohanian

2008-01-01

236

46 CFR 42.30-35 - The Winter North Atlantic Load Line.  

Science.gov (United States)

...between the meridians of 15° W. and 50° W.; and (2) The whole of the North Atlantic Winter Seasonal Zone I, the Shetland Islands to be considered as being on the boundary. [CGFR 68-60, 33 FR 10069, July 12,...

2010-10-01

237

Effects of temper level on the dependence of fatigue crack growth threshold and crack closure on the prior austenitic grain size  

Science.gov (United States)

An attempt has been made to systematically investigate the effects of microstructural parameters, such as the prior austenite grain size (PAGS), in influencing the resistance to fatigue crack growth (FCG) in the near-threshold region under three different temper levels in a quenched and tempered high-strength steel. By austenitizing at various temperatures, the PAGS was varied from about 0.7 to 96 ?m. The microstructures with these grain sizes were tempered at 200 °C, 400 °C, and 530 °C and tested for fatigue thresholds and crack closure. It has been found that, in general, three different trends in the dependence of both the total threshold stress intensity range, ? K th , and the intrinsic threshold stress intensity range, ? K eff, th , on the PAGS are observable. By considering in detail the factors such as cyclic stress-strain behavior, environmental effects on FCG, and embrittlement during tempering, the present observations could be rationalized. The strong dependence of ? K th and ? K eff, th on PAGS in microstructures tempered at 530 °C has been primarily attributed to cyclic softening and thereby the strong interaction of the crack tip deformation field with the grain boundary. On the other hand, a less strong dependence of ? K th and ? K eff, th on PAGS is suggested to be caused by the cyclic hardening behavior of lightly tempered microstructures occurring in 200 °C temper. In both microstructures, crack closure influenced near-threshold FCG (NTFCG) to a significant extent, and its magnitude was large at large grain sizes. Microstructures tempered at the intermediate temperatures failed to show a systematic variation of ?Kth and ?Keff, th with PAGS. The mechanisms of intergranular fracture vary between grain sizes in this temper. A transition from “microstructure-sensitive” to “microstructure-insensitive” crack growth has been found to occur when the zone of cyclic deformation at the crack tip becomes more or less equal to PAGS. Detailed observations on fracture morphology and crack paths corroborate the grain size effects on fatigue thresholds and crack closure.

Ravichandran, K. S.; Dwarakadasa, E. S.

1990-12-01

238

Communicating Certainty About Nuclear Winter  

Science.gov (United States)

I have been spending much of my time in the past several years trying to warn the world about the continuing danger of nuclear weapons, and that the solution is a rapid reduction in the nuclear arsenal. I feel that a scientist who discovers dangers to society has an ethical duty to issue a warning, even if the danger is so scary that it is hard for people to deal with. The debate about nuclear winter in the 1980s helped to end the nuclear arms race, but the planet still has enough nuclear weapons, even after reductions planned for 2017 under the New START treaty, to produce nuclear winter, with temperatures plunging below freezing in the summer in major agricultural regions, threatening the food supply for most of the planet. New research by myself, Brian Toon, Mike Mills, and colleagues over the past six years has found that a nuclear war between any two countries, such as India and Pakistan, using 50 atom bombs each of the size dropped on Hiroshima could produce climate change unprecedented in recorded human history, and a world food crisis because of the agricultural effects. This is much less than 1% of the current global arsenal. Communicating certainty - what we know for sure - has been much more effective than communicating uncertainty. The limited success I have had has come from persistence and serendipity. The first step was to do the science. We have published peer-reviewed articles in major journals, including Science, Nature, Proceedings of the National Academy of Sciences, Journal of Geophysical Research, Atmospheric Chemistry and Physics, Physics Today, and Climatic Change. But policymakers do not read these journals. Through fairly convoluted circumstances, which will be described in this talk, we were able to get papers published in Scientific American and the Bulletin of Atomic Scientists. I have also published several encyclopedia articles on the subject. As a Lead Author of Chapter 8 (Radiative Forcing) of the recently published Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), I inserted a paragraph pointing out that volcanic eruptions serve as an analog that supports new work on nuclear winter. This is the first time that nuclear winter has been in the IPCC report. I will tell the story of the discussions within our chapter, with review editors, and with the IPCC leadership that resulted in a box in Chapter 8 that discusses nuclear winter. We gave a briefing to John Holdren, the President's Science Advisor, about the work. Daniel Ellsberg, Fidel Castro, and Mikhail Gorbachev found out about our work, and used the results to appeal for nuclear abolition. In 2013 the work was featured at the Conference on the Humanitarian Impact of Nuclear Weapons in Oslo, Norway attended by 132 nations, and I gave a TEDx talk, I published an opinion piece on the CNN website, and I gave an invited public lecture in Nagasaki, Japan, all about the climatic consequences of nuclear war. I am now using Twitter and Facebook to communicate about nuclear winter. The threat that nuclear weapons pose to the planet is a much easier problem to solve than global warming. We need to eliminate nuclear weapons so we have the luxury of working on the global warming problem without the possibility of the existential global threat still posed by the global nuclear arsenal.

Robock, A.

2013-12-01

239

Effects of tempering on internal friction of carbon steels  

Energy Technology Data Exchange (ETDEWEB)

Research highlights: {yields} Time tempering dependent microstructure of two steels is studied by internal friction. {yields} Internal friction indicates the interactions of dislocations with carbon and carbides. {yields} Internal friction detects the first stage of tempering. {yields} Precipitation hardening is detected by the decrease in the background. - Abstract: Two steels containing 0.626 and 0.71 wt.% carbon have been studied to determine the effects of tempering on the microstructure and the internal friction. The steels were annealed at 1093 K, quenched into water and tempered for 60 min at 423 K, 573 K and 723 K. The increase of the tempering time diminishes the martensite tetragonality due to the redistribution of carbon atoms from octahedrical interstitial sites to dislocations. Internal friction spectrum is decomposed into five peaks and an exponential background, which are attributed to the carbide precipitation and the dislocation relaxation process. Simultaneous presence of peaks P1 and P2 indicates the interaction of dislocations with the segregated carbon and carbide precipitate.

Hoyos, J.J., E-mail: jjhoyos@unal.edu.co [Grupo de Ciencia y Tecnologia de los Materiales, Universidad Nacional de Colombia, Sede Medellin, Carrera 80 Numero 65-223, Medellin (Colombia); Ghilarducci, A.A., E-mail: friccion@cab.cnea.gov.ar [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Instituto Balseiro-Universidad Nacional de Cuyo, Consejo Nacional de Investigaciones Cientificas y Tecnologicas, Av. Bustillo 9500, 8400 Bariloche RN (Argentina); Salva, H.R., E-mail: salva@cab.cnea.gov.ar [Centro Atomico Bariloche, Comision Nacional de Energia Atomica, Instituto Balseiro-Universidad Nacional de Cuyo, Consejo Nacional de Investigaciones Cientificas y Tecnologicas, Av. Bustillo 9500, 8400 Bariloche RN (Argentina); Chaves, C.A., E-mail: cachaves@unal.edu.co [Grupo de Ciencia y Tecnologia de los Materiales, Universidad Nacional de Colombia, Sede Medellin, Carrera 80 Numero 65-223, Medellin (Colombia); Velez, J.M., E-mail: jmvelez@unal.edu.co [Grupo de Ciencia y Tecnologia de los Materiales, Universidad Nacional de Colombia, Sede Medellin, Carrera 80 Numero 65-223, Medellin (Colombia)

2011-04-15

240

TEM studies of tempered structural steels with Ni  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The reason for writing this paper was to describe the influence of Ni addition on the microstructure of structural steels after tempering. In this investigation, four model alloys of the variable concentration of Ni and constant concentration of carbon and other elements were used.Design/methodology/approach: The alloys were melted in air and hot forged into bars 20×35 mm. The samples for investigations were machined after normalizing. All samples for TEM investigations were used in quenched and tempered conditions. Quenching was performed in oil at room temperature. After quenching samples were tempered at 200°C for 2 h. The microstructure of the investigated steels were investigated using JEM200CX transmission electron microscope.Findings: An increase of Ni content in investigated structural steels causes a decrease of ? carbide concentration in their microstructure after tempering at 200°C for 2 hours. Cementite precipitates in these steels independently on the boundaries of martensite needles boundaries and on the twin boundaries in the areas in which the precipitates of ? carbide dissolved. Research limitations/implications: Presented results may be used to design new technologies of tempering of structural steels with nickel addition.Originality/value: Morphology of ? carbides precipitates.

J. Pacyna

2007-03-01

 
 
 
 
241

Zones of climatic severity of Galicia; Zonas de severidad climatica de Galicia  

Energy Technology Data Exchange (ETDEWEB)

Winter and Summer climatic Severities, calculated according to the specifications of the Spanish Technical Building Code (TBC), are obtained for the 315 municipality capitals of Galicia, and each capital is assigned to the corresponding Climatic Severity Zones, according to the TBC. Altitudes of change of Climatic Severities, the winter heating degree days and summer cooling degree days were previously calculated, as well as the accumulated solar radiation of the winter and summer periods. (Author)

Vazquez, M.; Izquierdo, P.; Pose, M.

2008-07-01

242

Agricultural impacts on ecosystem functioning in temperate areas of North and South America  

Science.gov (United States)

Land use has a large impact on ecosystem functioning, though evidences of these impacts at the regional scale are scarce. The objective of this paper was to analyze the impacts of agricultural land use on ecosystem functioning (radiation interception and carbon uptake) in temperate areas of North and South America. From land cover maps generated using high-resolution satellite images we selected sites dominated by row crops (RC), small grain crops (SG), pastures (PA), and rangelands (RA) in the Central Plains of USA and the Pampas of Argentina. These two regions share climatic characteristics and the agricultural conditions (crop types) are also very similar. Both areas were originally dominated by temperate grasslands. In these sites we extracted the temporal series of the normalized difference vegetation index (NDVI) from the NOAA satellites for the period 1989-1998 and calculated the mean seasonal NDVI curve for each site. Additionally, we calculated the mean annual NDVI, the maximum NDVI, the date of the year when the max NDVI was recorded and the interannual variability of these three attributes. We compared the mean values of each NDVI-derived attribute between land cover types and between continents. The NDVI seasonal patterns for each land cover type were roughly similar between the Central Plains and the Pampas during the growing season. The largest differences were observed during the winter and spring, when the NDVI of all land cover types in the Central Plains remained at lower values than in the Pampas. This was probably caused by the high annual thermal amplitude in the Central Plains that results in a much more restricted growing season. As a result of these differences in the shape of the NDVI curve, the mean annual NDVI in the Central Plains was lower than in the Pampas for all land cover types but the maximum NDVI did not differ importantly. In both regions, row crops delayed the date of the NDVI peak, small grain crops advanced it and pastures did not change it importantly, compared with rangelands. The interannual variability of the NDVI attributes was higher for small grains than for row crops in both regions. However, small grains crops were consistently more variable between years in the Central Plains than in the Pampas. The opposite occurred with pastures and rangelands, which were more variable in the Pampas than in the Central Plains. This paper confirms and generalizes previous findings that showed important imprints of land use on ecosystem functioning in temperate ecosystems. Our results support the idea that the changes in land cover that have occurred in the Central Plains and the Pampas leaded to similar changes in the way that ecosystems absorb solar radiation and in the patterns of carbon uptake.

Guerschman, Juan Pablo; Paruelo, José María

2005-07-01

243

A note on the water budget of temperate glaciers  

Directory of Open Access Journals (Sweden)

Full Text Available In this note, the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy due to the downward motion of mass (ice, snow, meltwater and rain. A mathematical formulation of the dissipation is developed and applied to a simple glacier geometry. In the next step, meltwater production resulting from enhanced ice motion during a glacier surge is calculated. The amount of melt energy available follows directly from the lowering of the centre of gravity of the glacier. To illustrate the concept, schematic calculations are presented for a number of glaciers with different geometric characteristics. Typical dissipative melt rates, expressed as water-layer depth averaged over the glacier, range from a few centimetres per year for smaller glaciers to half a metre per year for Franz Josef Glacier, one of the most active glaciers in the world (in terms of mass turnover. The total generation of meltwater during a surge is typically half a metre. For Variegated Glacier a value of 70 cm is found, for Kongsvegen 20 cm. These values refer to water layer depth averaged over the entire glacier. The melt extit{rate} depends on the duration of the surge. It is generally an order of magnitude greater than water production by `normal' dissipation. On the other hand, the additional basal melt rate during a surge is comparable in magnitude with the water input from meltwater and precipitation. This suggests that enhanced melting during a surge does not grossly change the total water budget of a glacier. Basal water generated by enhanced sliding is an important ingredient in many theories of glacier surges. It provides a positive feedback mechanism that actually makes the surge happen. The results found here suggest that this can only work if water generated by enhanced sliding accumulates in a part of the glacier base where surface meltwater and rain have no or very limited access. This finding seems compatible with the fact that, on many glaciers, surges are initiated in the lower accumulation zone.

J. Oerlemans

2013-09-01

244

A note on the water budget of temperate glaciers  

Directory of Open Access Journals (Sweden)

Full Text Available In this note the total dissipative melting in temperate glaciers is studied. The analysis is based on the notion that the dissipation is determined by the loss of potential energy, due to the downward motion of mass (ice, snow, meltwater and rain. A mathematical formulation of the dissipation is developed and applied to a simple glacier geometry. In a next step, meltwater production resulting from enhanced ice motion during a glacier surge is calculated. The amount of melt energy available follows directly from the lowering of the centre of gravity of the glacier. To illustrate the concept, schematic calculations are presented for a number of glaciers with different geometric characteristics. Typical dissipative melt rates, expressed as water-layer depth averaged over the glacier, range from a few cm per year for smaller glaciers to half a meter per year for Franz-Josef Glacier, one of the most active glaciers in the world (in terms of mass turnover. The total generation of meltwater during a surge is typically half a meter. For Variegated Glacier a value of 70 cm is found, for Kongsvegen 20 cm. These values refer to water layer depth averaged over the entire glacier. The melt rate depends on the duration of the surge. It is generally an order of magnitude larger than the water production by "normal" dissipation. On the other hand, the additional basal melt rate during a surge is comparable in magnitude to the water input from meltwater and precipitation. This suggests that enhanced melting during a surge does not grossly change the total water budget of a glacier. Basal water generated by enhanced sliding is an important ingredient of many theories of glacier surges. It provides a positive feedback mechanism that actually makes the surge happen. The results found here suggest that this can only work if water generated by enhanced sliding is accumulating in a part of the glacier base where surface meltwater and rain has no or very limited access. This finding seems compatible with the fact that on many glaciers surges are initiated in the lower accumulation zone.

J. Oerlemans

2013-06-01

245

Candidate Planets in the Habitable Zones of Kepler Stars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A key goal of the Kepler mission is the discovery of Earth-size transiting planets in "habitable zones" where stellar irradiance maintains a temperate climate on an Earth-like planet. Robust estimates of planet radius and irradiance require accurate stellar parameters, but most Kepler systems are faint, making spectroscopy difficult and prioritization of targets desirable. The parameters of 2035 host stars were estimated by Bayesian analysis and the probabilities p(HZ) that ...

Gaidos, Eric

2013-01-01

246

Synoptic influence on winter temperature and precipitation in western Montana  

Science.gov (United States)

In this dissertation, synoptic climatology is used to investigate the spatial variability of winter temperature and precipitation over western Montana. Statistical description of winter precipitation in the region shows significant variability in both spatial and temporal characteristics. Using rotated principal component analysis (RCPA) four distinct regions, that are physically reasonable, reveal the effect of the dominant airmasses and topography over the region. These regions are the northwestern part which show mainly the influence of northwesterly flow from the Pacific and of the topography of the rocky mountains; the mostly dry eastern part influenced mainly by the rain-shadow zone of the Rockies, the area between the rain-shadow zone and the moist western area where the precipitation pattern can be explained by storms which occur from the edge of fronts that move from Alberta down into the high plains; and the southern part region which has very high elevations but and for the most part characterized by the effect of the mountain ranges in northern Wyoming on the southerly flow from the gulf. From a 4 x 5 array of self organizing maps of daily winter 700mb geopotential height, patterns to winter precipitation show a strong influence of the westerly airmasses as main contributor of precipitation. The spatial analysis of precipitation for each of the synoptic types also shows the effect of topography. This makes the northwestern part of the region the major source of snowpack for the region. Using the results from the circulation patterns, the influence of synoptic types on winter temperature and precipitation are discussed by analyzing the variability of lapse rate and orographic rate with synoptic types. The results show that lapse rates and orographic rates vary significantly with synoptic types over western Montana. Estimates of temperature and precipitation using MTCLIM shows that synoptic types have significant influence on our ability to predict these elements in mountain regions. More precise values of lapse rates and orographic rates would predict temperature and precipitation better than long term averages of lapse rates and generalized isohyetal values.

Goshit, Sunday Damina

247

Resilience of soil microbial activity and of amino acid dynamics to the removal of plant carbon inputs during winter Resiliência da atividade microbiana e da dinâmica de amino-ácidos na remoção das adições de carbono das plantas, durante o inverno  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Many temperate agricultural soils have prolonged periods in the winter when plant carbon inputs to the soil are low. Soil maintained at low temperature in the absence of plants was used to simulate the conditions in a vineyard soil during winter. In a four month simulated overwintering period we showed that the concentration of dissolved organic carbon and nitrogen in soil solution slowly declined alongside heterotrophic soil respiration. Measurements of free amino acid concentrations and tur...

Avramides, Elizabeth J.; Matina Christou; Jones, David L.

2009-01-01

248

Magnetic nondestructive technology for detection of tempered martensite embrittlement  

Energy Technology Data Exchange (ETDEWEB)

A nondestructive eddy current technique is used to evaluate tempered martensite embrittlement in 4340 AISI steels after quench and tempering in the range 240-550 Degree-Sign C. A relation between the responses of the magnetic induction (normalized impedance of the coil) and destructive Charpy impact test results has been established. The study shows that the eddy current method could be used to separate brittle parts due to the microstructure changes. - Highlights: Black-Right-Pointing-Pointer Occurrence of tempered martensite embrittlement in 4340 AISI steels was evaluated. Black-Right-Pointing-Pointer A reliable relation between EC output and Charpy impact test results was obtained. Black-Right-Pointing-Pointer EC technique was used to separate brittle parts due to the microstructure changes.

Kashefi, Mehrdad; Rafsanjani, Ali [Department of Materials Science and Metallurgical Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Kahrobaee, Saeed, E-mail: Saeed_kahrobaee@yahoo.com [Department of Materials Science and Metallurgical Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Alaee, Moeen [Department of Materials Science and Metallurgical Engineering, Engineering Faculty, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

2012-11-15

249

Resistance to small plastic strains during martensite tempering under tension  

International Nuclear Information System (INIS)

The mechanism of plastic deformation of martensite of a series of hardened steels (N18, 20KhG, 50KhFA and others) during tempering under tension and the role of residual internal microstresses and phase transformations are studied. It is shown that martensite low resistance to small plastic deformations during tempering under tension which is usually associated with phase transformations depends as well on the level of residual internal microstresses in the martensite structure. The decrease of resistance to deformation in the course of the decomposition of a solid solution is due to weakening of martensitic matrix because of carbon departure from the solid solution and carbide coarsening. An assumption is made that martensite plastic deformation during tempering under tension is realized at the expense of the directed microplastic deformation in the regions of higher concentration of internal stresses

1982-11-01

250

Radiation processing of temperate fruits of Kashmir valley  

International Nuclear Information System (INIS)

Kashmir valley is famous for its temperate horticulture. Main temperate fruits grown commercially in the valley include apple, pear, peach, plum, cherry, strawberry and apricot. These fruits being perishable and susceptible to microbial spoilage, have a short shelf-life. The short shelf-life in an impediment in their transportation and marketing and results in huge losses. Study was carried out at NRL, Srinagar to investigate the effect of gamma irradiation on the keeping quality of most of these fruits. The effect of gamma irradiation alone and in combination with other techniques like controlled low temperature storage, edible polysaccharide coating and calcium chloride treatment was studied in detail. The results revealed that there is a great potential for the use of radiation in extending the storage life of most of the temperate fruits produced in the valley of Kashmir. (author)

2011-01-01

251

Water-vapor content in the atmosphere of arid zone  

Science.gov (United States)

The variation in water-vapor content W in the atmosphere of the arid zone is studied. The seasonal oscillations in W for the arid zone are characterized by changes in the moisture content from 2.3 to 3.6 times during the transition from winter to summer. The summer-fall period is characterized by a well-expressed midday minimum of moisture content. In winter the moisture content monotonically decreases during the day. In spring the water-vapor content has a wide maximum in midday. The water-vapor content in the atmosphere during dust haze increases up to two times.

Abdullaev, S. F.; Maslov, V. A.; Nazarov, B. I.; Salikhov, T. Kh.

2014-03-01

252

Developmental switches in a family of temperate phages  

Digital Repository Infrastructure Vision for European Research (DRIVER)

P2 is the prototype phage of the non-lambdoid P2 family of temperate phages. A developmental switch determines whether a temperate phage will grow lytically or form lysogeny after infection. P2 related phages have two face-to-face located promoters controlling the lysogenic and the lytic operon respectively, and two repressors. The immunity C repressor of P2 is the first gene of the lysogenic operon and it represses the lytic promoter. The Cox protein, the first gene of the lytic operon, is m...

Ahlgren Berg, Alexandra

2005-01-01

253

Type 1,1-operators on spaces of temperate distributions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This paper is a follow-up on the author’s general definition of pseudo-differential operators of type 1,1, in Hörmander’s sense. It is shown that such operators are always defined on the smooth functions that are temperate; and moreover are defined and continuous on the space of temperate distributions, whenever they fulfil the twisted diagonal condition of Hörmander, or more generally when they belong to the self-adjoint subclass. Continuity in Lp -Sobolev spaces and Hölder–Zygmund ...

Johnsen, Jon

2010-01-01

254

Interactions of Lactobacillus bulgaricus Temperate Bacteriophage 0448 with Host Strains  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lactobacillus bulgaricus LT4(0448) is a lysogenic strain from which a temperate bacteriophage can be induced by mitomycin C or UV irradiation. Lactobacillus lactis CNRZ 326 is an indicator strain for the temperate phage 0448, but this strain lyses only in the presence of Ca2+ ions. A resistant culture developed secondarily after phage lysis and grew normally in MRS broth but again lysed abruptly if Ca2+ ions were added after two or three transfers. This behavior of the secondary culture and i...

Cluzel, Pierre-jean; Serio, Jacques; Accolas, Jean-pierre

1987-01-01

255

Discrete developmental roles for temperate cereal grass VERNALIZATION1/FRUITFULL-like genes in flowering competency and the transition to flowering.  

Science.gov (United States)

Members of the grass subfamily Pooideae are characterized by their adaptation to cool temperate climates. Vernalization is the process whereby flowering is accelerated in response to a prolonged period of cold. Winter cereals are tolerant of low temperatures and flower earlier with vernalization, whereas spring cultivars are intolerant of low temperatures and flower later with vernalization. In the pooid grasses wheat (Triticum monococcum, Triticum aestivum) and barley (Hordeum vulgare), vernalization responsiveness is determined by allelic variation at the VERNALIZATION1 (VRN1) and/or VRN2 loci. To determine whether VRN1, and its paralog FRUITFULL2 (FUL2), are involved in vernalization requirement across Pooideae, we determined expression profiles for multiple cultivars of oat (Avena sativa) and wheat with and without cold treatment. Our results demonstrate significant up-regulation of VRN1 expression in leaves of winter oat and wheat in response to vernalization; no treatment effect was found for spring or facultative growth habit oat and wheat. Similar cold-dependent patterns of leaf expression were found for FUL2 in winter oat, but not winter wheat, suggesting a redundant qualitative role for these genes in the quantitative induction of flowering competency of oat. These and other data support the hypothesis that VRN1 is a common regulator of vernalization responsiveness within the crown pooids. Finally, we found that up-regulation of VRN1 in vegetative meristems of oat was significantly later than in leaves. This suggests distinct and conserved roles for temperate cereal grass VRN1/FUL-like genes, first, in systemic signaling to induce flowering competency, and second, in meristems to activate genes involved in the floral transition. PMID:18024551

Preston, Jill C; Kellogg, Elizabeth A

2008-01-01

256

CO2 flux in a cool-temperate deciduous forest (Quercus mongolica of Mt. Nam in Seoul, Korea  

Directory of Open Access Journals (Sweden)

Full Text Available The Namsan Ecological Tower Site based on a flux tower was equipped with eddy covariance and automatic opening/closing chamber systems to collect long-term continuous measurements of CO2 flux, such as the net ecosystem exchange(NEE and soil CO2 efflux in a cool-temperate Quercus mongolica forest. The mean concentrations of atmosphericCO2 (705 mg/m3 during the summer were smaller than those measured (770 mg/m3 during the winter. The mean CO2flux during the summer period was negative (-0.34 mg m-2 s-1, while that during the winter period was positive (0.14 mgm-2 s-1. CO2 was deposited from the atmosphere to the surface in the summer. The daily mean value of soil CO2 effluxincreased from spring to summer. The seasonal pattern in the rate of soil CO2 efflux tightly followed the seasonal patternin soil temperatures. The Q10 values for soil CO2 efflux varied in a range from 2.12 to 3.26, and increased with increasingsoil depth. The maximum value of total carbon uptake (i.e., NEE during the growing season was -8 g CO2 m-2 day-1. At thesame time, the rate of soil CO2 efflux was 6.9 g CO2 m-2 day-1. The amplitude of flux variations in NEE was approximately14% larger than those in soil CO2 efflux. These results suggest that in cool-temperate regions of the Korean peninsula,the forest ecosystem of Q. mongolica may have a larger atmospheric CO2 uptake, due primarily to its high photosyntheticcapacity and low ecosystem respiration.

Seung Jin Joo

2011-03-01

257

Two-stage phenomenon of temper brittleness in metallic amorphous alloy type transition metal-metalloid  

International Nuclear Information System (INIS)

Correlation of integral heat release evolution of relaxation spectra and mechanical characteristics of AMA (based on Fe-Ni) of transition metal-metalloid type on second irreversible stage tempering brittleness is established. Numerical criteria permitting to determine transition to secondary stage of temper brittleness according to integral heat release is obtained. Temper brittleness duration is determined by time of incubation period of surface crystallization. Microscopic model of secondary stage of temper brittleness is proposed

1994-01-01

258

El Nino Winter of 1997-1998.  

Science.gov (United States)

The winter of 1997-1998 was marked by a record breaking El Nino event and unusual extremes in parts of the country. Overall, the winter (December 1997- February 1998) was the second warmest and seventh wettest since 1895. Severe weather events included fl...

T. Ross N. Lott S. McCown D. Quinn

1998-01-01

259

Climate signatures in corals of the tropical-temperate transition zone (Late Miocene, Crete/Greece)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present study describes a Late Miocene (early Tortonian - early Messinian) transitional carbonate system that combines elements of tropical and cool-water carbonate systems (Irakleion Basin, island of Crete, Greece). As documented by stratal geometries, the submarine topography of the basin was controlled by tilting blocks. Coral reefs formed by Porites and Tarbellastrea occurred in a narrow clastic coastal belt along a „central Cretan landmass“, and steep escarpments formed by faulti...

Reuter, Markus

2006-01-01

260

Spiders and subsidies: results from the riparian zone of a coastal temperate rainforest.  

Science.gov (United States)

1. Aquatic insects emerging from streams can provide an important energy subsidy to recipient consumers such as riparian web-building spiders. This subsidy has been hypothesized to be of little importance where the primary productivity of the recipient habitat exceeds that of the donor habitat. 2. To test this hypothesis, we manipulated emerging stream insect abundance in a productive riparian rainforest in a replicated design using greenhouse-type exclosures, contrasted with unmanipulated stream reaches (four exclosures on two streams). 3. Experimental exclosures resulted in a 62.9% decrease in aquatic insect abundance in exclusion reaches compared with control reaches. The overall density of riparian spiders was significantly positively correlated with aquatic insect abundances. Horizontal orb weavers (Tetragnathidae) showed a strong response to aquatic insect reduction - abundance at exclosure sites was 57% lower than at control sites. Several spider families that have not been associated with tracking aquatic insect subsidies also showed significantly decreased abundance when aquatic insects were reduced. 4. This result is contrary to predictions of weak subsidy effects where recipient net primary productivity is high. These results suggest that predicting the importance of resource subsidies for food webs requires a focus on the relative abundance of subsidy materials in recipient and donor habitats and not simply on the total flux of energy between systems. PMID:17584374

Marczak, Laurie B; Richardson, John S

2007-07-01

 
 
 
 
261

Challenges in the nutrition and management of herbivores in the temperate zone  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The expected higher global demand for animal proteins and the competition for starch and sugars between food, fuel and feed seem to favour herbivores that convert solar energy captured in fibrous plants into animal products. However, the required higher production level of herbivores questions the sustainability of this conversion. An increase in herbivore production can be achieved by increasing the number of animals associated with the increasing demand of plant biomass or by improving the ...

Vuuren, A. M.; Chilibroste, P.

2013-01-01

262

Detecting `Temperate' Jupiters: the prospects of searching for transiting gas giants in Habitable Zones  

Science.gov (United States)

Wide-field photometric surveys in search of transiting extrasolar planets are now numerous and have met with some success in finding hot Jupiters. These transiting planets have very short periods and very small semimajor axes, facilitating their discovery in such surveys. Transiting planets with longer periods present more of a challenge, since they transit their parent stars less frequently. This paper investigates the effects of observing windows on detecting transiting planets by calculating the fraction of planets with a given period that have zero, one (single), two (double), or >=3 (multiple) transits occurring while observations are being taken. We also investigate the effects of collaboration by performing the same calculations with combined observing times from two wide-field transit survey groups. For a representative field of the 2004 observing season, both XO and SuperWASP experienced an increase in single and double transit events by up to 20-40 per cent for planets with periods 14 ratio of the data. We therefore conclude that the investment of resources needed to investigate more sophisticated photometry calibrations or examine single and double transit events from wide-field surveys might be a worthwhile endeavour. The collaboration of different transit surveys by combining photometric data can greatly increase the number of transits observed for all semimajor axes. In addition, the increased number of data points can improve the signal-to-noise ratio of binned data, increasing the chances of detecting transiting extrasolar planets.

Fleming, S. W.; Kane, S. R.; McCullough, P. R.; Chromey, F. R.

2008-05-01

263

Specific saturation magnetization of cementite resulting from tempering of cobalt and nickel steels  

Energy Technology Data Exchange (ETDEWEB)

Results of studying specific saturation magnetization of cementite formed in cobalt and nickel steels in the case of isothermal tempering, are presented. It is shown that tempering temperature increase or ageing duration increase bring about the increase of specific magnetization of cementite saturation of both cobalt and nickel steels. Co and Ni dissolving in cementite during steel tempering decreases its specific saturation magnetization.

Yatsura, M.M.; Kirichok, P.P.; Yatsura, O.R. (Ivano-Frankovskij Gosudarstvennyj Pedagogicheskij Inst. (Ukrainian SSR))

1984-01-01

264

On specific saturation magnetization of cementite resulting from tempering of cobalt and nickel steels  

International Nuclear Information System (INIS)

Results of studying specific saturation magnetization of cementite formed in cobalt and nickel steels in the case of isothermal tempering, are presented. It is shown that tempering temperature increase or ageing duration increase bring about the increase of specific magnetization of cementite saturation of both cobalt and nickel steels. Co and Ni dissolving in cementite during steel tempering decreases its specific saturation magnetization

1984-01-01

265

Numerical Simulation of Soda-Lime Silicate Glass Tempering  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The paper deals with the computation of residual and transient stresses in a tempered glass plate. The modelling takes into account the viscoelastic behavior and the structural relaxation of glass. The evolution of stresses with time during the rapid cooling is computed. Simulation results are compared with experimental ones from the literature available. Levels of transient tensile stress in the surface are analysed.

1996-01-01

266

Microstructure properties of tempered D6ac steel  

Energy Technology Data Exchange (ETDEWEB)

Highlights: Black-Right-Pointing-Pointer We evaluated microstructure properties of tempered D6ac steel. Black-Right-Pointing-Pointer The forming process has a high microhardness of martensite phase at surface layer. Black-Right-Pointing-Pointer XRD spectra observed that the residual austenite and/or mixed structures of ferrite with the precipitation of carbides. Black-Right-Pointing-Pointer Ferrite decreased and that of carbon and chromium elements increased upon increasing the tempering temperature. - Abstract: The aim of this study was to determine the microstructure and surface mechanical properties of tempered D6ac. The obtained microstructures exhibited a number of misfit dislocations from work hardening, with the degree of disorder dislocation decreasing gradually upon increasing the temperature at 650 Degree-Sign C. XRD spectra observed that the residual austenite and/or mixed structures of ferrite with the precipitation of carbides at 650 Degree-Sign C will result in a softer state than that of the room temperature specimen. In addition, the forming process has a high microhardness of martensite phase at surface layer, subjected to heat treatment until a stable state is achieved. The content of ferrite atoms decreased and that of carbon and chromium elements increased upon increasing the tempering temperature.

Lian Derming, E-mail: lianderming@gmail.com [Department of Mechanical Engineering, Chin-Yi University of Technology, Taichung 411, Taiwan (China)

2013-01-01

267

Influence of Deformation on the Tempering Of 1045 Martensite.  

Science.gov (United States)

As-quenched martensitic 1045 steel bars were plastically deformed by drawing through a die. Hardness, dilation, and color carbon (Eggertz test) were used to follow the changes during tempering to 800 F as a function of deformation. The deformed steel incr...

M. F. Miller N. N. Breyer

1969-01-01

268

Parallel tempering and decorrelation of topological charge in full QCD  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The improvement of simulations of QCD with dynamical Wilson fermions by combining the Hybrid Monte Carlo algorithm with parallel tempering is studied on $10^4$ and $12^4$ lattices. As an indicator for decorrelation the topological charge is used.

Ilgenfritz, E. -m; Kerler, W.; Mu?ller-preussker, M.; Stu?ben, H.

2000-01-01

269

Tempered Water Lower Port Connector Structural Analysis Verification  

Energy Technology Data Exchange (ETDEWEB)

Structural analysis of the lower port connection of the Tempered Water System of the Cold Vacuum Drying Facility was performed. Subsequent detailed design changes to enhance operability resulted in the need to re-evaluate the bases of the original analysis to verify its continued validity. This evaluation is contained in Appendix A of this report. The original evaluation is contained in Appendix B.

CREA, B.A.

2000-05-05

270

Groundwater flow modelling of periods with temperate climate conditions - Forsmark  

Energy Technology Data Exchange (ETDEWEB)

As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Forsmark site during temperate conditions; i.e. from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 12,000 AD. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a hydrogeological base case (reference case conceptualisation) and then in an examination of various areas of uncertainty within the current understanding by a series of model variants. The hydrogeological base case models at three different scales, 'repository', 'site' and 'regional', make use of continuous porous medium (CPM), equivalent continuous porous medium (ECPM) and discrete fracture network (DFN) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Swan, David (Serco Technical Consulting Services (United Kingdom)); Marsic, Niko (Kemakta Konsult AB (Sweden)); Follin, Sven (SF GeoLogic AB (Sweden))

2010-11-15

271

Groundwater flow modelling of periods with temperate climate conditions - Forsmark  

International Nuclear Information System (INIS)

As a part of the license application for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different climate conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. This report concerns the modelling of a repository at the Forsmark site during temperate conditions; i.e. from post-closure and throughout the temperate period up until the receding shoreline leaves the modelling domain at around 12,000 AD. The collation and implementation of onsite hydrogeological and hydrogeochemical data from previous reports are used in the construction of a hydrogeological base case (reference case conceptualisation) and then in an examination of various areas of uncertainty within the current understanding by a series of model variants. The hydrogeological base case models at three different scales, 'repository', 'site' and 'regional', make use of continuous porous medium (CPM), equivalent continuous porous medium (ECPM) and discrete fracture network (DFN) models. The use of hydrogeological models allow for the investigation of the groundwater flow from a deep disposal facility to the biosphere and for the calculation of performance measures that will provide an input to the site performance assessment. The focus of the study described in this report has been to perform numerical simulations of the hydrogeological system from post-closure and throughout the temperate period. Besides providing quantitative results for the immediate temperate period following post-closure, these results are also intended to give a qualitative indication of the evolution of the groundwater system during future temperate periods within an ongoing cycle of glacial/inter-glacial events

2010-01-01

272

Effect of temper on environmental fatigue crack propagation in 7000-series aluminum alloys  

Energy Technology Data Exchange (ETDEWEB)

In contrast to stress corrosion, the effect of overaging temper on environmental fatigue crack propagation rate in the 7000-series aluminum alloy/aqueous-chloride solution system is nil, moderately beneficial, or detrimental depending on loading frequency. For both peak and overaged AA7075 plate, Paris regime fatigue crack growth rates are accelerated up to 10-fold by cyclic loading in 3.5% NaCl solution compared to fatigue in moist air for the SL-crack orientation. Crack growth is intersubgranular for the T6 microstructure, but transgranular-brittle for the T7 case. Cracking at low f is dominated by corrosion product induced crack closure that is enhanced by overaging. At intermediate to high f, environmental fatigue is due to hydrogen embrittlement and rate limited by H diffusion over a crack tip process zone distance established by local stress. The relationship between plateau crack growth rate and critical frequency for f-dependent EFCP is predicted by a H diffusion model. Plateau regime transgranular-brittle EFCP in overaged AA7075 is slower than intersubgranular cracking in the T6 microstructure, but persists to higher f{sub CRIT}, requiring either rapid H diffusion or reduced crack tip H for process zone embrittlement of the overaged case. (orig.)

Gasem, Z.M.; Gangloff, R.P. [Virginia Univ., Charlottesville, VA (United States). Dept. of Mater. Sci. and Eng.

2000-07-01

273

Autumn and winter anomalies in ionospheric absorption as measured by riometers  

Science.gov (United States)

Seasonal variation of ionospheric absorption has been studied on the basis of riometer (A2) measurements obtained over a wide latitude range. In agreement with the results of earlier studies of A1 radio wave absorption, equinoctial maxima of approximately equal amplitude are observed in the auroral zone and near the equator. At mid-latitudes riometer absorption maximizes during the fall season, whereas the A1 data show a semi-annual variation with maxima occurring in summer and winter. The autumn maximum, or autumn anomaly, in riometer absorption is observed at much higher geographic latitude in the southern than in the northern hemisphere but at comparable geomagnetic latitudes in both hemispheres. The secondary maximum in riometer absorption at mid-latitudes during the winter months, the winter anomaly, is seen only if absorption is calculated at constant solar zenith angle. The different methods for determining a quiet-day curve are discussed.

Rosenberg, T. J.; Detrick, D. L.; Ranta, H.; Ranta, A.

1983-04-01

274

Temper outbursts in paediatric obsessive-compulsive disorder and their association with depressed mood and treatment outcome.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Temper outbursts in youth with obsessive-compulsive disorder (OCD) are a common source of concern, but remain poorly understood. This study examined a set of hypotheses related to: (a) the prevalence of temper outbursts in paediatric OCD, (b) the associations of temper outbursts with OCD severity and depressive symptoms; and (c) the influence of temper outbursts on treatment response.

Krebs, G.; Bolhuis, K.; Heyman, I.; Mataix-cols, D.; Turner, C.; Stringaris, A.

2013-01-01

275

ROV Survey of Winter Quarters Bay  

Science.gov (United States)

Title : ROV Survey of Winter Quarters Bay Type : Antarctic EAM NSF Org: OD / OPP Date : January 24 ... ice pier; (2) the ROV can go deeper than a person in SCUBA gear; (3) the ROV with a mapping device ...

276

Starling Dispersal from a Winter Roost.  

Science.gov (United States)

Starling roosting behavior is considered in terms of resource acquisition. Our hypothesis is that dispersing starlings behave to maximize the efficiency and rate of energy gain. This hypothesis can explain much of the winter starling roosting behavior. Th...

W. J. Hamilton W. M. Gilbert

1969-01-01

277

Mojave sandy desert habitat in Winter (February)  

Science.gov (United States)

By winter in non-drought years, the Mojave has received several inches of rain and healthy vegetation will begin to break ground by February. However, during drought years, vegetation will not experience its rapid growth season until spring.

Katie Hale (California State University, Fullerton;Student, Biological Sciences)

2007-01-06

278

Earth-Sun Geometry: Winter Solstice Animation  

Science.gov (United States)

The representation depicts the position of the Earth relative to the Sun during the southern hemisphere's winter solstice and includes line of latitude and the angle of the Sun's rays at the Tropic of Capricorn.

Pidwirny, Michael; Okanagan, Scott J.

279

The Exxon Valdez winter monitoring program results  

International Nuclear Information System (INIS)

This paper reports that Eighteen stations in Prince William Sound have been monitored on a monthly basis as part of the winter studies program developed by NOAA for scientific support at the Exxon Valdez oil spill. The objectives of the winter monitoring program were to: determine the persistence of oil at stations representative of the various shoreline types, degrees of exposure, extent of oiling, and treatment received during the summer of 1989; track the winter storm activity through the deployment of meteorological stations in the Sound; monitor the beach morphology changes and correlate them with winter storm intensity; quantify the oil changes at the stations and estimate the amount of oil remaining on the shoreline as of spring 1990; and characterize the weathering trends in chemical composition of the residual oil in both surface and subsurface sediments, for determination of treatability requirements and toxicity/bioavailability of oil remaining on the shoreline in 1990

1990-05-15

280

Supercooling and Freezing in Winter Dormant Animals  

Science.gov (United States)

This resource is a manual for instructing students in a laboratory exercise examining the effects of winter-time supercooling and freezing on animals. This lab would be a suitable supplement to animal physiology or physiological ecology courses.

William D. Schmid (University of Minnesota;)

1988-01-01

 
 
 
 
281

Heavy tempering of large steel castings and forgings  

International Nuclear Information System (INIS)

When standard grade Cr-Mo-Ni low-alloy steels of high hardenability are employed for manufacture of large castings and forgings of high integrity, their composition can be modified by certain additions. In this article the various effects of Cr, Mo and V are dealt with on the basis of their influence on the properties of the steel grade BS 826M31. The effects of modification, to this steel by increasing the molybdenum content to 1,0% or additions of 0,2% and 0,4% vanadium, on stress relaxation, hardenability, reversible temper embrittlement (RTE), tempering resistance, embrittlement, chemical composition and charpy impact energy are illustrated. 11 refs., 13 figs., 2 tabs

1988-01-01

282

Microstructure properties of tempered D6ac steel  

Science.gov (United States)

The aim of this study was to determine the microstructure and surface mechanical properties of tempered D6ac. The obtained microstructures exhibited a number of misfit dislocations from work hardening, with the degree of disorder dislocation decreasing gradually upon increasing the temperature at 650 °C. XRD spectra observed that the residual austenite and/or mixed structures of ferrite with the precipitation of carbides at 650 °C will result in a softer state than that of the room temperature specimen. In addition, the forming process has a high microhardness of martensite phase at surface layer, subjected to heat treatment until a stable state is achieved. The content of ferrite atoms decreased and that of carbon and chromium elements increased upon increasing the tempering temperature.

Lian, Derming

2013-01-01

283

Simulation of Residual Stresses at Holes in Tempered Glass  

DEFF Research Database (Denmark)

This work presents a full 3D numerical study of the residual stresses in tempered (toughened) glass near holes using Narayanaswamyâ??s model for the tempering process. It is the objective of the paper to elucidate the influence on the minimal residual compressive stresses at holes from variations in: the far-field stress, plate thickness, hole diameter and the interaction between holes and edges and corners. The work presents novel results for the sensitivity of the residual stresses to geometric features and provides a design tool for estimating residual stresses at holes for different geometries. An example of how to extrapolate the results in terms of far-field stresses is given.

Nielsen, Jens Henrik; Olesen, John Forbes

2010-01-01

284

Reversible temper brittleness on tensile tests at room temperature  

International Nuclear Information System (INIS)

Tensile tests were carried out on unnotched test pieces at room temperature and three strain rates: 2,5x10"-"4, 2,5x10"-"3 and 1,0x10"-"2 s"-"1 in a low alloy No-Cr-Mo steel to observe the variation in its mechanical properties with the occurrence of reversible temper brittleness. The brittle samples showed a sensitivity of 50"0C in a 48 hour heat treatment at 500"0C. The tests showed that at the strain rate of 2,5x10"-"4 s"-"1 there are statistically significant differences between the elongations of the material in the brittle and the nonbrittle and regenerated states. A short review of reversible temper brittleness is given and a theory suggested for the mechanism

1976-10-01

285

Effect of tempering on corrosion resistance of cast aluminium bronzes  

International Nuclear Information System (INIS)

The subject of this study is corrosion resistance of aluminium bronzes, which are copper base alloys containing aluminium up to 12% with additions of nickel, iron and manganese. The main conclutions that can be drawn are: (1) The dealloying corrosion resistance of nickel-aluminium bronze is much better than that of aluminium bronze with iron and manganese additions, but it is not immune; (2) The dealloying corrosion resistance of aluminium bronzes can be improved by appropiate heat treatments. The best properties were obtained by temperering between 600 and 800 deg C, depending on the initial microstructure; (3) In crevice conditions, where local acidification can occur, dealloying of aluminium bronzes is a consequence of the preferential attack of aluminium-rich phases. By appropriate tempering, a uniform distribution of aluminium-rich phases is obtained and the continous path for selective corrosion is not formed

1985-08-27

286

The winter St. Helena climate index and extreme Benguela upwelling  

Science.gov (United States)

Climate changes in the subtropical South-east Atlantic turn out to be well described by the St. Helena Island Climate Index (HIX) and observed fluctuations are in good agreement with inter-decadal variability of the entire South Atlantic Ocean. Year-to-year variations of the averaged austral winter HIX (July-September), representative of the main upwelling season, were compared with (i) corresponding averages of the geostrophic alongshore component of the south-east trade wind (SET) between St. Helena Island in the south-west and Luanda/Angola in the north-east, (ii) the meridional distribution of surface waters colder than 13 °C to characterise intense Benguela upwelling (IBU), and (iii) the meridional position of the Angola-Benguela Frontal Zone (ABFZ) determined by means of sea surface temperature images for offshore distances between 50 and 400 km. Temporal changes of these parameters were investigated and showed that the frequency of consecutive years of strong and relaxed Benguela upwelling is characterised by a quasi-cycle of about 11-14 years. It is proposed that the index of the winter HIX may be used as a 'surveyor's rod' to describe interannual changes in the Benguela upwelling regime as well as those of the embedded marine ecosystem.

Hagen, Eberhard; Agenbag, Jacobus J.; Feistel, Rainer

2005-09-01

287

[Fusariosis of seeds of winter triticale].  

Science.gov (United States)

The results of studying the mycoflora of winter triticale grains and seedlings after artificial and natural inoculation are presented. The species of Fusarium, Alternaria, Helminthosporium, Septoria, Cladosporium, Penicillium, Rhizopus were identified. Fusarium spp., prevailed over other fungi as to the number of its isolates. Its isolates (n = 142) were distinguished, 5 species were identified. It is significant, that most isolates of Fusarium graminearum caused a disease of grains. The species F. oxysporum dominated on winter triticale seedlings. PMID:16786634

Dermenko, O P

2006-01-01

288

Yellow-cedar and western redcedar ecophysiological response to fall, winter and early spring temperature conditions  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Western redcedar (Thuja plicata Donn) and yellow-cedar (Chamaecyparis nootkatensis (D. Don) Spach) populations originating from an elevation zone where these two species naturally coexist were monitored to define their performance patterns in response to seasonal temperature conditions within the fall, winter and early spring field conditions of the Pacific Northwest coastal forest region. Western redcedar and yellow-cedar populations were measured for changes in growth rhythms, photosyntheti...

2006-01-01

289

Efficient assignment of the temperature set for Parallel Tempering  

International Nuclear Information System (INIS)

We propose a simple algorithm able to identify a set of temperatures for a Parallel Tempering Monte Carlo simulation, that maximizes the probability that the configurations drift across all temperature values, from the coldest to the hottest ones, and vice versa. The proposed algorithm starts from data gathered from relatively short Monte Carlo simulations and is straightforward to implement. We assess its effectiveness on a test case simulation of an Edwards–Anderson spin glass on a lattice of 123 sites.

2012-02-20

290

Adaptive Parallel Tempering for Stochastic Maximum Likelihood Learning of RBMs  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Restricted Boltzmann Machines (RBM) have attracted a lot of attention of late, as one the principle building blocks of deep networks. Training RBMs remains problematic however, because of the intractibility of their partition function. The maximum likelihood gradient requires a very robust sampler which can accurately sample from the model despite the loss of ergodicity often incurred during learning. While using Parallel Tempering in the negative phase of Stochastic Maximum...

Desjardins, Guillaume; Courville, Aaron; Bengio, Yoshua

2010-01-01

291

Viral Loop Dynamics in Temperate and Polar Freshwaters  

Digital Repository Infrastructure Vision for European Research (DRIVER)

All cellular organisms in aquatic environments are susceptible to virus attack. Viruses are the smallest but most abundant biological entities in freshwaters. This thesis describes interactions between viruses and bacteria in temperate and polar freshwaters with particular emphasis on Arctic and Antarctic aquatic systems. Free virus-like particles in freshwaters are vulnerable and exposed and as parasites their survival is dependent on the existence of a suitable host. I found that high conce...

Sa?wstro?m, Christin

2006-01-01

292

Rootstocks used for temperate fruit trees in Turkey: an overview  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Most of the fruit tree orchards in Turkey are grafted onto rootstocks, except chestnuts and cornelian cherries, which are generally propagated by seeds. The main rootstocks used by Turkish growers for temperate fruit trees nowadays are: wild apple seedlings, M.9 and MM.106 for apples; wild pear, in particular Pyrus eleagrifolia L. seedlings for pears; wild peach seedlings for peaches; wild plum seedlings for plums; seedlings of Mazzard and Mahaleb, very recently clonally propagated Gisela 5 a...

Ercisli, Sezai; Esitken, Ahmet; Orhan, Emine; Ozdemir, Ozlem

2006-01-01

293

Computer simulation of quenched and tempered steel properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose: The algorithm of estimation of mechanical properties based on steel hardness has been established.Design/methodology/approach: Numerical modelling of hardness distribution in as-quenched steel specimen was performed by involving the results of simple experimental test, i.e., Jominy-test. Hardness of quenched and tempered steel has been expressed as function of maximal hardness of actual steel and hardness of actual steel with 50% of martensite in microstructure, according to the time...

2011-01-01

294

TEM studies of tempered structural steels with Ni  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose: The reason for writing this paper was to describe the influence of Ni addition on the microstructure of structural steels after tempering. In this investigation, four model alloys of the variable concentration of Ni and constant concentration of carbon and other elements were used.Design/methodology/approach: The alloys were melted in air and hot forged into bars 20×35 mm. The samples for investigations were machined after normalizing. All samples for TEM investigations were used in...

2007-01-01

295

Erosion risk assessment of active coastal cliffs in temperate environments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The potentially negative consequences resulting from cliff recession are a matter of serious concern in many coastal areas worldwide. The assessment of these kind of processes has traditionally been performed by calculating average cliff recession rates and projecting them into the future, without taking into consideration the diverse factors affecting cliff dynamics and stability. In this work a new, practical method is presented to evaluate cliff erosion risk on temperate environments, by a...

Del Ri?o, Laura; Gracia, Francisco Javier

2009-01-01

296

Comparison Between Atmospheric Turbidity Coefficients of Desert and Temperate Climates  

Directory of Open Access Journals (Sweden)

Full Text Available , and Angström turbidity coefficients, b, are calculated from measurements of broadband filters at Helwan, Egypt, which has a desert climate. A linear regression model is to be determined between the Linke factor and the Angström turbidity coefficient. This relation is compared with similar relations reported for a temperate climate [Prague, Czech Republic]. This comparison is made to determine whether a universal relation exists between these two important coefficients, or whether the relation is location dependent.

Hamdy K. Elminir

2001-01-01

297

Evolution of temperate pathogens: the bacteriophage/bacteria paradigm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Taking as a pattern, the T4 and lambda viruses interacting with each other and with their Gram-negative host, Escherichia coli, a general model is constructed for the evolution of 'gentle' or temperate pathogens. This model is not simply either pure group or kin selection, but probably is common in a variety of host-parasite pairs in various taxonomic groups. The proposed mechanism is that for its own benefit the pathogen evolved ways to protect i...

Koch Arthur L

2007-01-01

298

Nitrous oxide emission reduction in temperate biochar-amended soils  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Biochar, a pyrolysis product of organic residues, is an amendment for agricultural soils to improve soil fertility, sequester CO2 and reduce greenhouse gas (GHG) emissions. In highly weathered tropical soils laboratory incubations of soil-biochar mixtures revealed substantial reductions for nitrous oxide (N2O) and carbon dioxide (CO2). In contrast, evidence is scarce for temperate soils. In a three-factorial laboratory i...

Felber, R.; Hu?ppi, R.; Leifeld, J.; Neftel, A.

2012-01-01

299

Temperate Pollen Genera in the Eocene (Claiborne) Flora, Alabama.  

Science.gov (United States)

Pollen, spores, hystrichospherids, dinoflagellates, and the fresh-water alga Pediastrum occur in marine clays at the classic Claiborne Bluffs locality, Alabama. The presence of Ephedra pollen provides the first documented Tertiary record of this genus from the southeastern states. The occurrence of several characteristically temperate genera lends support to the idea that a deciduous hardwood forest was present in the Appalachian uplands during the Eocene. PMID:17813748

Gray, J

1960-09-23

300

Nanostructure of a cold drawn tempered martensitic steel  

CERN Multimedia

The carbon atom distribution in a tempered martensitic steel processed by cold drawing was investigated with a three-dimensional atom probe. Data clearly show that cementite starts to decompose at the early stage of deformation. This indicates that the driving force of cementite decomposition during plastic deformation is not related to a strong increase of the interfacial energy. Carbon atmospheres were also analysed. They probably result from pipe diffusion of carbon atoms along dislocations pined by Fe3C carbides.

Sauvage, X; Malandain, J J; Pareige, P; Sauvage, Xavier; Quelennec, Xavier; Malandain, Jean-Jacques; Pareige, Philippe

2006-01-01

 
 
 
 
301

Nanostructure of a cold drawn tempered martensitic steel  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The carbon atom distribution in a tempered martensitic steel processed by cold drawing was investigated with a three-dimensional atom probe. Data clearly show that cementite starts to decompose at the early stage of deformation. This indicates that the driving force of cementite decomposition during plastic deformation is not related to a strong increase of the interfacial energy. Carbon atmospheres were also analysed. They probably result from pipe diffusion of carbon atoms along dislocation...

Sauvage, Xavier; Quelennec, Xavier; Malandain, Jean-jacques; Pareige, Philippe

2006-01-01

302

FERTILIZING OF A WINTER WHEAT SOWN AFTER WINTER WHEAT AND COMMON SAINFOIN ON ORDINARY BLACK SOIL ????????? ?????? ???????, ?????????? ????? ?????? ??????? ? ????????? ?? ????????? ????????????  

Directory of Open Access Journals (Sweden)

Full Text Available Distinctions of soil under a winter wheat after a winter wheat and common sainfoin in provision of moisture and feed elements are revealed. Influence of autumn application of complete fertilizer and spring nitric dosage compensations on productivity and quality of a winter wheat are established; dependence of fertilizers’ effect from nitrate nitrogen contents in the soil is shown. Optimum dozes combinations on both predecessors are found

Hatlamadzhian A. L.

2011-12-01

303

Multi-proxy summer and winter precipitation reconstruction for southern Africa over the last 200 years  

Science.gov (United States)

This study presents the first consolidation of palaeoclimate proxy records from multiple archives to develop statistical rainfall reconstructions for southern Africa covering the last two centuries. State-of-the-art ensemble reconstructions reveal multi-decadal rainfall variability in the summer and winter rainfall zones. A decrease in precipitation amount over time is identified in the summer rainfall zone. No significant change in precipitation amount occurred in the winter rainfall zone, but rainfall variability has increased over time. Generally synchronous rainfall fluctuations between the two zones are identified on decadal scales, with common wet (dry) periods reconstructed around 1890 (1930). A strong relationship between seasonal rainfall and sea surface temperatures (SSTs) in the surrounding oceans is confirmed. Coherence among decadal-scale fluctuations of southern African rainfall, regional SST, SSTs in the Pacific Ocean and rainfall in south-eastern Australia suggest SST-rainfall teleconnections across the southern hemisphere. Temporal breakdowns of the SST-rainfall relationship in the southern African regions and the connection between the two rainfall zones are observed, for example during the 1950s. Our results confirm the complex interplay between large-scale teleconnections, regional SSTs and local effects in modulating multi-decadal southern African rainfall variability over long timescales.

Neukom, Raphael; Nash, David J.; Endfield, Georgina H.; Grab, Stefan W.; Grove, Craig A.; Kelso, Clare; Vogel, Coleen H.; Zinke, Jens

2014-05-01

304

Comparative visual ecophysiology of mid-Atlantic temperate reef fishes.  

Science.gov (United States)

The absolute light sensitivities, temporal properties, and spectral sensitivities of the visual systems of three mid-Atlantic temperate reef fishes (Atlantic spadefish [Ephippidae: Chaetodipterus faber], tautog [Labridae: Tautoga onitis], and black sea bass [Serranidae: Centropristis striata]) were studied via electroretinography (ERG). Pelagic Atlantic spadefish exhibited higher temporal resolution but a narrower dynamic range than the two more demersal foragers. The higher luminous sensitivities of tautog and black sea bass were similar to other benthic and demersal coastal mid-Atlantic fishes. Flicker fusion frequency experiments revealed significant interspecific differences at maximum intensities that correlated with lifestyle and habitat. Spectral responses of the three species spanned 400-610 nm, with high likelihood of cone dichromacy providing the basis for color and contrast discrimination. Significant day-night differences in spectral responses were evident in spadefish and black sea bass but not tautog, a labrid with characteristic structure-associated nocturnal torpor. Atlantic spadefish responded to a wider range of wavelengths than did deeper-dwelling tautog or black sea bass. Collectively, these results suggest that temperate reef-associated fishes are well-adapted to their gradient of brighter to dimmer photoclimates, representative of their unique ecologies and life histories. Continuing anthropogenic degradation of water quality in coastal environments, at a pace faster than the evolution of visual systems, may however impede visual foraging and reproductive signaling in temperate reef fishes. PMID:24285711

Horodysky, Andrij Z; Brill, Richard W; Crawford, Kendyl C; Seagroves, Elizabeth S; Johnson, Andrea K

2013-01-01

305

Superinfection exclusion reveals heteroimmunity between Pseudomonas aeruginosa temperate phages.  

Science.gov (United States)

Temperate siphophages (MP29, MP42, and MP48) were isolated from the culture supernatant of clinical Pseudomonas aeruginosa isolates. The complete nucleotide sequences and annotation of the phage genomes revealed the overall synteny to the known temperate P. aeruginosa phages such as MP22, D3112, and DMS3. Genome-level sequence analysis showed the conservation of both ends of the linear genome and the divergence at the previously identified dissimilarity regions (R1 to R9). Protein sequence alignment of the c repressor (ORF1) of each phage enabled us to divide the six phages into two groups: D3112 group (D3112, MP29, MP42, and MP48) and MP22 group (MP22 and DMS3). Superinfection exclusion was observed between the phages belonging to the same group, which was mediated by the specific interaction between the c repressor and the cognate operator. Based on these, we suggest that the temperate siphophages prevalent in the clinical strains of P. aeruginosa represent at least two distinct heteroimmunity groups. PMID:24871978

Chung, In-Young; Bae, Hee-Won; Jang, Hye-Jung; Kim, Bi-O; Cho, You-Hee

2014-06-01

306

Land and water interface zones  

Energy Technology Data Exchange (ETDEWEB)

This paper reports analyses of C pools and fluxes in land-water interface zones. The objective was to determine the role of these zones as global sinks of atmospheric CO[sub 2] as part of a larger effort to quantify global C sinks and sources in the past (ca. 1850), the present, and the foreseeable future (ca. 2050). Assuming the world population doubles by the year 2050, storage of atmospheric C in reservoirs will also double, as will river loads of atmospheric C and nutrients. It is estimated that C sinks in temperate and boreal wetlands have decreased by about 50%, from 0.2 to 0.1 Gt C yr[sup -1], since 1850. The total decrease for wetlands may be considerably larger when tropical wetlands are taken into account, changes in cultivation practices and improved sampling of methaneogenesis have caused estimates of CH[sub 4] emissions from ricelands to drop substantially from 150 to 60 Tg yr[sup -1]. Even with doubled N and P loads, rivers are unlikely to fertilize more than about 20% of the new primary production in the coastal ocean. The source of C for this new production may not be the atmosphere, however, because the coastal ocean exchanges large quantities of DIC with the open ocean. Until the C fluxes from air-sea exchange of CO[sub 2] and DIC are better quantified, the C-sink potential of the coastal ocean will remain a major uncertainty in the global C cycle. Land use management must consider the unique C sinks in coastal and alluvial wetlands in order to minimize the future negative impacts of agriculture and urban development. Relative to the other systems examined at the workshop, the C-sink capacity of the ocean (excluding estuaries) is not likely to be measurably affected in the foreseeable future by the management scenarios considered at the workshop. 52 refs., 3 tabs.

Downing, J.P.; Meybeck, M.; Orr, J.C.; Twilley, R.R.; Scharpenseel, H.-W. (Pacific Northwest Laboratories, Sequim, WA (United States). Marine Sciences Lab.)

1993-10-01

307

Spent nuclear fuel project cold vacuum drying facility tempered water and tempered water cooling system design description  

International Nuclear Information System (INIS)

This document provides the System Design Description (SDD) for the Cold Vacuum Drying Facility (CVDF) Tempered Water (TW) and Tempered Water Cooling (TWC) System . The SDD was developed in conjunction with HNF-SD-SNF-SAR-002, Safety Analysis Report for the Cold Vacuum Drying Facility, Phase 2, Supporting Installation of Processing Systems (Garvin 1998), The HNF-SD-SNF-DRD-O02, 1998, Cold Vacuum Drying Facility Design Requirements, and the CVDF Design Summary Report. The SDD contains general descriptions of the TW and TWC equipment, the system functions, requirements and interfaces. The SDD provides references for design and fabrication details, operation sequences and maintenance. This SOD has been developed for the SNFP Operations Organization and shall be updated, expanded, and revised in accordance with future design, construction and startup phases of the CVDF until the CVDF final ORR is approved

1998-01-01

308

Prediction of hardness in pieces of quenched and tempered steel  

International Nuclear Information System (INIS)

This presentation describes the first stage of a work plan to obtain a simple software, for predicting properties at certain points of a quenched and tempered piece. In this first stage, this prediction is limited to cylindrical pieces made with steels whose chemical composition is within a certain range. The methodology basically consists of obtaining , from experimental data, a mathematical tool able to predict the hardness value, for Jominy test piece ends made with this type of steel. This meant beginning with the analysis of the usual forms of theoretical calculation of Jominy curves of quenched samples, which resulted in a proposal to modify the Just equation. Two different mathematical methods were then developed, that could predict hardness values in tempered Jominy test pieces. One, based on the determination of polynomic equations, that reproduces the loss of hardness at points along the test piece, base on the quenching value and as a function of the tempering temperature. The other one, which uses the lineal multidimensional interpolation method, because of its ease of application, has been selected as the mathematical tool to use in the software under development. At this stage of the work, the relationship between the points on the piece and those on the Jominy test pieces is carried out by the Lamont method and the representative variable of the temperature/time combination for the tempering process itself, is obtained with software based on the Hollomon and Jaffe expression. Data is needed to define: a) chemical composition and grain size of the steel used, b) diameter of the piece, c) 'HG' severity of the quenching medium d) temperature and time of the tempering. The work's second stage continued with the addition of hardness values measured in Jominy test pieces made with other steels. The chemical composition and grain size data of each steel introduced are converted by the software into one more variable, using the concept of ideal critical diameter. The result from the computer process should be the 'U curve of hardnesses', based on the prediction of the hardness value that the material will have, at points along the radius of a circular piece. So the engineer now has an easy, quick design tool with acceptable margins of error. When selecting the steel to use in producing the mechanical piece, he/she can make a better comparison of the possible offers of treated material, with respect to the data provided by the calculation of requests (CW)

2006-12-01

309

Tailored tempering. Customized material properties for hot-stamped parts; Tailored Tempering. Massgeschneiderte Werkstoffeigenschaften fuer waermeumgeformte Bauteile  

Energy Technology Data Exchange (ETDEWEB)

The requirements placed on vehicle crash performance and fuel consumption have increased consistently in recent years. Technologies such as the press hardening of manganese-boron steels can help reduce car body weight while optimizing service properties. ThyssenKrupp Steel Europe has developed an enhanced press hardening process called 'tailored tempering' that makes it possible to exploit the full range of strength levels offered by steel through precise control of the cooling process in the forming die. (orig.)

Sikora, Sascha; Banik, Janko; Graff, Stephane; Laurenz, Robert; Lenze, Franz-Josef [ThyssenKrupp Steel Europe AG, Dortmund (Germany). FuE

2012-07-01

310

An empirical exploration of the world oil price under the target zone model  

International Nuclear Information System (INIS)

This paper investigates the behavior of the world oil price based on the first-generation target zone model. Using anecdotal data during the period of 1988-1999, we found that OPEC has tried to maintain a weak target zone regime for the oil price. Our econometric tests suggest that the movement of the oil price is not only manipulated by actual and substantial interventions by OPEC but also tempered by market participants' expectations of interventions. As a consequence, the non-linear model based on the target zone theory has very good forecasting ability when the oil price approaches the upper or lower limit of the band

2002-11-01

311

Rural Poultry Populations and Strains in Two Agro-Ecological Zones of Nigeria  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A study was conducted in Plateau State of Nigeria which has two distinct agro-ecological zones; a humid sub-temperate region in the North and a sub-humid hotter region that is part of the Northern Guinea Savanna ecological zone of Nigeria in the South. A sample of 1240 farmers from two Local Governments in each of the two ecological zones were surveyed to assess the poultry population and strains of birds as a prelude to the introduction of interventions for control of Newcastle Disease and o...

Dafwang, I. I.; Musa, U.; Abdu, P. A.; Umoh, J. U.

2010-01-01

312

Winter barley mutants created in the Ukraine  

International Nuclear Information System (INIS)

Full text: Increasing fodder and protein production is one of the objectives of the development of agriculture in Ukraine. Higher productivity of fodder crops, due to new highly productive varieties, is the means to meet this aim. Winter barley is an important crop for fodder purposes. The climate of the Ukraine is favourable for growing this crop. The areas used for the growth of winter barley are however, small (500,000-550,000 ha) and there is a shortage of good quality varieties. The main aim of the work was therefore to create new varieties of highly productive winter barley, of good quality. The new varieties and mutation lines of winter barley were created under the influence of water solutions of N-nitroso-N-methylurea (NMH - 0,012, 0,005%), N-nitroso-N-ethylurea (NEH - 0,05; 0.025; 0,012%) ethyleneimine (EI - 0,02; 0,01; 0,005%) on winter barley seeds of the varieties of local and foreign selections. On the basis of many years of investigations (1984-94) the following mutations were described: hard-grained, winter-hardiness, earliness, middle-maturity, late-maturity, wide and large leaves, narrow leaves, multinodal, great number of leaves, great number of flowers, strong stem (lodging resistant), tallness, semi-dwarfness, dwarfness, and high productivity. Particularly valuable are mutants with high productivity of green bulk. Their potential yield is 70 t/ha. As a result of the work two varieties of winter barley 'Shyrokolysty' and 'Kormovy' were released into the State register of plant varieties of the Ukraine. The other valuable mutant genotypes are used in cross breeding programmes. (author)

2001-07-01

313

Neopaleozoic flora in stratigraphic zones of Gondwana  

Energy Technology Data Exchange (ETDEWEB)

Carboniferous and Permian floristic sequences in Gondwana and adjacent areas are analyzed. These data are distributed on palaeogeographic maps that correspond to four chronologic segments: lower Carboniferous-early middle Carboniferous, early middle Carboniferous-middle late Carboniferous, lower Permian and upper Permian. A correlation of zones and floral assemblages during the late Palaeozoic is proposed on the base of recent data. The distribution of possible periglacial sediments (diamictites) is also included in the sequences. It is concluded that palaeogeography conditioned the floristic development in Gondwana. An independent evolution of different gondwanic areas is suggested by the continuous change in their palaeolatitudinal disposition. South Africa and South America had a similar development during the Permian and belong to the Northafroamerican Palaeofloristic Province. During the same period, on the other hand, Australia, India and Antartica had a more temperate climatic regime, being located nearer the pole; they may belong to the Indoaustralian Palaefloristic Province. 44 refs.

Archangelsky, S.

1984-01-01

314

Microstructural evolution of low carbon Cr-Mo steel tempered by induction heating  

Energy Technology Data Exchange (ETDEWEB)

Microstructural evolution of a low alloy steel tempered at various temperature in the range of 300-700 degree C using induction heating method was examined. A series of microstructural evolution such as precipitation of acicular cementite with particular orientation and formation of spheroidized cementite was observed with increasing tempering temperature. Comparing to the tempered steel with salt-bath, similar tempered microstructure could be obtained at higher temperature by induction heating. Tensile stress-strain curves of the tempered steel revealed that the excellent formability of the low alloy steel would be achieved by tempering in the range of 500-700 degree C with induction heating method which is commercially applicable heat-treatment process.

Ahn, Soon Tae; Lee, Sang Lae [Pusan National Univ., Pusan (Korea, Republic of)

2002-01-01

315

Dilatometric and hardness analysis of C45 steel tempering with different heating-up rates  

Directory of Open Access Journals (Sweden)

Full Text Available Modelling of technological processes of heat treatment or welding, involving multiple heat source transitions, requires considering the phenomenon of tempering. In work have been presented results of dilatometric research of hardened C45 steel subjected to tempering. The analysis of the influence of heating rate at the kinetic determined from dilatometric curves has been made. There have also been estimated quantities of transformation expansions and thermal expansion coefficients of hardening and tempering structures (austenite, ferrite, pearlite, martensite and sorbite. The analysis of tempering time influence on the hardness of tempered steel has been made. Functions associating hardness with tempering time (rate of heating-up in technological processes based on short-timed action of a heat source (eg. laser treatment have been suggested.

A. Kulawik

2012-01-01

316

Microstructural evolution of low carbon Cr-Mo steel tempered by induction heating  

International Nuclear Information System (INIS)

Microstructural evolution of a low alloy steel tempered at various temperature in the range of 300-700 degree C using induction heating method was examined. A series of microstructural evolution such as precipitation of acicular cementite with particular orientation and formation of spheroidized cementite was observed with increasing tempering temperature. Comparing to the tempered steel with salt-bath, similar tempered microstructure could be obtained at higher temperature by induction heating. Tensile stress-strain curves of the tempered steel revealed that the excellent formability of the low alloy steel would be achieved by tempering in the range of 500-700 degree C with induction heating method which is commercially applicable heat-treatment process

2002-01-01

317

Parallel allochronic divergence in a winter moth due to disruption of reproductive period by winter harshness.  

Science.gov (United States)

The disruption of reproductive timing by climatic harshness may result in the temporal isolation of conspecific populations and, ultimately, in speciation. However, whether temporal isolation alone can act as the force initiating speciation and how often the same type of climatic disruption results in the divergence of allochronic populations in a lineage are largely unknown. The reproductive period of the winter geometrid moth Inurois punctigera is separated into early and late winter in habitats with severe winters, but not in habitats with mild winters, suggesting that the reproductive season is disrupted by the harshness of the mid-winter period. Here, we show that sympatric pairs of early- and late-winter populations that differ in origin exist in different regions, suggesting a parallel divergence of reproductive timing. In each region, significant genetic differentiation exists between these early- and late-winter populations, suggesting that the temporal reproductive isolation has persisted. Moreover, we demonstrate that the temporal isolation, in comparison with geographic isolation, contributes greatly to the genetic differentiation among geographic and temporal populations by an analysis of molecular variance and by a comparison of genetic differentiations (F(ST) ) between geographic populations with and without difference in reproductive season. Our results suggest that adaptive divergence of allochronically reproducing populations has occurred independently in different regions, implying the generality of the role of temporal isolation in initiating speciation in a winter moth lineage. PMID:22098106

Yamamoto, Satoshi; Sota, Teiji

2012-01-01

318

An approach to the determination of winter chill requirements for different Ribes cultivars.  

Science.gov (United States)

Winter chilling is critical for flowering and fruiting of many temperate fruits, with evidence that blackcurrant (Ribes nigrum L.) cropping has been adversely affected by warm winters. Accurate models of chill accumulation in blackcurrant are required so that breeding strategies can be formulated for the generation of new cultivars with resilience to future climates. Existing models for chill accumulation have largely been derived from statistical correlation; here we report the derivation of improved models for blackcurrant using controlled environment treatments. Hardwood cuttings from a diverse set of cultivars were exposed to constant or varying chilling temperatures and the effects on bud break after transfer to a warm, permissive environment evaluated. The impact of different combinations of temperature and chilling periods were described in terms of their overall 'Effectiveness' (E). Clear genotypic differences were found, with excessive chilling often inhibiting bud break. There was a significant interaction between observed chilling response and the period of low temperature exposure. A number of chilling models to explain observed interactions between chilling temperature and time of exposure on bud break were compared; the most effective involved an optimal response to increasing chill accumulation. The effects of varying temperatures during chilling on bud break were complex, with warm temperature breaks substantially inhibiting bud development and cooler temperature breaks tending to enhance bud burst. The relevance of these models to generic studies of endodormancy is discussed, together with their potential application to the development of phenotyping screens for future breeding using diverse blackcurrant germplasm. PMID:22512943

Jones, H G; Hillis, R M; Gordon, S L; Brennan, R M

2013-01-01

319

Payment mechanisms for winter road maintenance services  

Directory of Open Access Journals (Sweden)

Full Text Available In countries with severe winters a major part of the annual budget for road maintenance is allocated on performance of winter road maintenance tasks. Finding appropriate remuneration forms to compensate entrepreneurs for performed road measures during winter is not an easy task in order to minimise or eliminate disputes and satisfy both client organisations and contractors. On the other hand improper reimbursement models lead either to the client’s annual budget imbalance due to unnecessary cost overruns or affect contractor’s cash-flow. Such cases in turn affect just-in-time winter road maintenance and then traffic safety. To solve such problems, a number of countries in cold regions like Sweden have developed different remuneration models based more on weather data called Weather Index. Therefore the objective of this paper is to investigate and evaluate the payment models applied in Sweden. The study uses a number of approaches namely; domestic questionnaire survey, analysis of a number of contract documents, a series of meetings with the project managers and an international benchmarking. The study recognised four remuneration models for winter maintenance service of which one based on weather data statistics. The study reveals the payment model based on weather data statistics is only applied for the roads with higher traffic flow and the model generates most uncertainty.

Adel Abdi

2013-12-01

320

Intraspecific Variation in Leaf Life Span for the Semi-evergreen Liana Akebia trifoliata is Caused by Both Seasonal and Aseasonal Factors in a Temperate Forest  

Directory of Open Access Journals (Sweden)

Full Text Available We investigated the leaf demography of a temperate woody liana, Akebia trifoliata, in a temperateforest in Japan. Akebia is semi-evergreen: some leaves are shed before winter, while others remain through thewinter. Previous studies of semi-evergreen species found that variation in leaf life span was caused by variationin the timing of leaf emergence. Leaves that appeared just before winter over-wintered, while leaves appearingearlier were shed. However, it is unclear whether leaves of the same cohort (i.e., leaves that appear at the sametime within a single site show variation in life span under the effect of strong seasonality. To separate variationin life span among the leaves in each cohort from variation among cohorts, we propose a new method - thesingle leaf diagram, which shows the emergence and death of each leaf. Using single leaf diagrams, our studyrevealed that Akebia leaves within a cohort showed substantial variation in life span, with some over-winteringand some not. In addition, leaves on small ramets in the understory showed great variation in life span, whileleaves on large ramets, which typically reach higher positions in the forest canopy, have shorter lives. As a result,small ramets were semi-evergreen, whereas large ramets were deciduous. The longer lives of leaves on smallramets can be interpreted as a shade-adaptive strategy in understory plants.

Koyama, Kohei

2008-08-01

 
 
 
 
321

MEJORAMIENTO DE TRIGOS HARINEROS (Triticum aestivum L. EN LA ZONA CENTRO SUR DE CHILE: CONTENIDO Y PRODUCCIÓN DE PROTEINA, Y VOLUMEN DE SEDIMENTACIÓN EN TRIGOS INVERNALES, ALTERNATIVOS Y PRIMAVERALES Genetic improvement of bread wheat (Triticum aestivum L. in the South Central zone of Chile: Protein content, production and sedimentation volume of winter, alternative and spring wheats  

Directory of Open Access Journals (Sweden)

Full Text Available Se realizaron cuatro experimentos de campo con diez variedades de trigos de invierno y hábito alternativo (grupo 1, y cuatro experimentos con once variedades de trigos de primavera (grupo 2, para evaluar el porcentaje y producción de proteína del grano, y el volumen de sedimentación. Los genotipos fueron desarrollados en el Proyecto de Mejoramiento de Trigo del Instituto de Investigaciones Agropecuarias (INIA, Centro Regional de Investigación Quilamapu. Lilifén fue la primera variedad mejorada en el grupo 1, y Mexifén en el grupo 2; por lo tanto ambas fueron usadas como referencia. Los experimentos se llevaron a cabo en suelos Andisoles del Campo Experimental Santa Rosa (INIA, Chillán, Chile, desde el año 1995 a 1998. Los porcentajes medios de proteína de las variedades de los grupos 1 y 2 fueron 9,6 %, y 10,8%, respectivamente. El promedio de producción de proteína de las variedades del grupo 1 fue 894,6 kg ha-1 mientras que en el grupo 2 este valor fue 968,4 kg ha-1. Los valores medios para sedimentación fueron 3,4 mL en el grupo 1 y 4,3 mL en el grupo 2. En relación a las variedades, los resultados demostraron que el trabajo de mejoramiento de trigo realizado entre 1968 y 1993 fue más exitoso en mejorar el contenido de proteína del grano que su calidadFour field experiments with ten winter and alternative varieties (group 1 and four experiments with eleven spring wheat varieties (group 2, were carried out to assess grain protein percentage, grain production and sedimentation volume. The tested genotypes were developed at the Quilamapu Wheat Breeding Program, Institute of Agricultural Research, INIA. Lilifen was the first breed variety improved in group 1, and Mexifen in group 2; as such both were used as references. The experiments were carried out in Andisoil soils at the Santa Rosa Experimental Field, Chillán, Chile, from 1995 to 1998. The mean protein percentage of varieties of groups 1 and 2 were 9.6 and 10.8%, respectively. The average protein production in group 1 was 894.6 kg ha-1, while in group 2 was 968.4 kg ha-1. The average sedimentation values were 3.4 mL in group 1 and 4.3 mL in group 2. With regard to varieties, results showed that breeding work carried out between 1968 and 1993 was more successful at improving protein content rather than quality.

Mario Mellado Z.

2001-04-01

322

Experimental warming does not enhance soil respiration in a semiarid temperate forest-steppe ecosystem  

DEFF Research Database (Denmark)

The influence of simulated climate change on soil respiration was studied in a field experiment on 4 m x 5 m plots in the semiarid temperate Pannonian sand forest-steppe. This ecosystem type has low productivity and soil organic matter content, and covers large areas, yet data on soil carbon fluxes are still limited. Soil respiration rate-measured monthly between April and November from 2003 to 2006-remained very low (0.09 - 1.53 mu mol CO2 m(-2) s(-1))in accordance with the moderate biological activity and low humus content of the nutrient poor, coarse sandy soil. Specific soil respiration rate ( calculated for unit soil organic matter content), however, was relatively high (0.36 - 7.92 mu mol CO g(-1) C(org)h(-1)) suggesting substrate limitation for soil biological activity. During the day, soil respiration rate was significantly lower at dawn than at midday, while seasonally clear temperature limitation in winter and water limitation in summer were detected. Between years, annual precipitation appeared to be important in determining soil carbon efflux intensity. Nocturnal warming increased soil temperature in 1 cm depth at dawn by 1.6 degrees C on the average, and decreased topsoil (0-11 cm) moisture content by 0.45 vol%. Drought treatment decreased soil moisture content by an average of 0.81 vol%. Soil respiration rate tended to decrease by 7-15% and 13-15% in response to heat and drought treatment, respectively, although the changes were not statistically significant. Nocturnal warming usually prevented dew formation, and that probably also influenced soil respiration. Based on these results, we expect a reduction in the volume and rate of organic matter turnover in this ecosystem in response to the anticipated climate change in the region.

Beier, Claus

2008-01-01

323

Tempering of Martensite in Dual-Phase Steels and Its Effects on Softening Behavior  

Science.gov (United States)

The isothermal and nonisothermal tempering of martensite in dual-phase (DP) steels was investigated mainly by analytical transmission electron microscopy, and the effect on softening behavior was studied. The isothermal tempering resulted in coarsening and spheroidization of cementite and complete recovery of laths. However, nonisothermal tempering manifested fine quasi-spherical intralath and platelike interlath cementite, decomposition of retained austenite, and partial recovery of laths. The distinct characteristic of nonisothermal tempering was primarily attributed to the synergistic effect of delay in cementite precipitation and insufficient time for diffusion of carbon due to rapid heating that delays the third stage of tempering. The finer size and platelike morphology of cementite coupled with partial recovery of lath resulted in reduced softening in nonisothermal tempering compared to severe softening in isothermal tempering due to large spheroidized cementite and complete recovery of lath substructure. The substitutional content of precipitated cementite in nonisothermal tempering was correlated to the richness of particular steel chemistry. Softening resistance during nonisothermal tempering was related to DP steel chemistry, i.e., Cr and Mn content. Fine cementite and less decomposed martensite in rich chemistry confer high resistance to softening compared to leaner chemistries, which indicated severe decomposition of martensite with coarser cementite.

Baltazar Hernandez, V. H.; Nayak, S. S.; Zhou, Y.

2011-10-01

324

Nuclear winter: the continuing debate. Student essay  

Energy Technology Data Exchange (ETDEWEB)

This essay examines the debate over the climatic consequences of global nuclear war as related in the so-called Nuclear Winter hypothesis. This review examines the major components of the theory and traces development of the scientific knowledge leading to a second phase of the controversy two years after the first hypothesis. The conclusions of the essay are that the original nuclear winter findings have been altered by later scientific study and, therefore, the political conclusions drawn by Carl Sagan in 1983 can no longer be supported by theory or facts. Continued use of the Crutzen-Birks (Ambio, 1982) and TTAPS (Science, December 1983) studies worst-case evidence from NCAR (Foreign Affairs, Summer 86) represents selective science. Arguing for strategic policy changes based on nuclear winter risks constitutes anti-nuclear rhetoric and not scientific reasoning.

Nida, A.V.

1987-03-23

325

Determining efficient temperature sets for the simulated tempering method  

Science.gov (United States)

In statistical physics, the efficiency of tempering approaches strongly depends on ingredients such as the number of replicas R, reliable determination of weight factors and the set of used temperatures, TR={T1,T2,…,TR}. For the simulated tempering (ST) in particular-useful due to its generality and conceptual simplicity-the latter aspect (closely related to the actual R) may be a key issue in problems displaying metastability and trapping in certain regions of the phase space. To determine TR’s leading to accurate thermodynamics estimates and still trying to minimize the simulation computational time, here a fixed exchange frequency scheme is considered for the ST. From the temperature of interest T1, successive T’s are chosen so that the exchange frequency between any adjacent pair Tr and Tr+1 has a same value f. By varying the f’s and analyzing the TR’s through relatively inexpensive tests (e.g., time decay towards the steady regime), an optimal situation in which the simulations visit much faster and more uniformly the relevant portions of the phase space is determined. As illustrations, the proposal is applied to three lattice models, BEG, Bell-Lavis, and Potts, in the hard case of extreme first-order phase transitions, always giving very good results, even for R=3. Also, comparisons with other protocols (constant entropy and arithmetic progression) to choose the set TR are undertaken. The fixed exchange frequency method is found to be consistently superior, specially for small R’s. Finally, distinct instances where the prescription could be helpful (in second-order transitions and for the parallel tempering approach) are briefly discussed.

Valentim, A.; da Luz, M. G. E.; Fiore, Carlos E.

2014-07-01

326

Hatchling turtles survive freezing during winter hibernation.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hatchlings of the painted turtle (Chrysemys picta marginata) are unique as the only reptile and highest vertebrate life form known to tolerate the natural freezing of extracellular body fluids during winter hibernation. Turtles survived frequent exposures to temperatures as low as -6 degrees C to -8 degrees C in their shallow terrestrial nests over the 1987-1988 winter. Hatchlings collected in April 1988 had a mean supercooling point of -3.28 +/- 0.24 degrees C and survived 24 hr of freezing ...

Storey, K. B.; Storey, J. M.; Brooks, S. P.; Churchill, T. A.; Brooks, R. J.

1988-01-01

327

Nuclear winter: The evidence and the risks  

International Nuclear Information System (INIS)

Global concern over nuclear extinction, centered on the holocaust itself, now has turned to the more terrifying consequences of a post-war nuclear winter: ''the long-term effects - destruction of the environment, spread of epidemic diseases, contamination by radioactivity, and ... collapse of agriculture-[that] would spread famine and death to every country.'' Nuclear Winter, the latest in a series of studies by a number of different groups is clinical, analytical, systematic, and detailed. Two physicists and biologist analyze the effects on the climate, plants, animals, and living systems; the human costs; the policy implications

1985-01-01

328

Nuclear winter: The evidence and the risks  

Energy Technology Data Exchange (ETDEWEB)

Global concern over nuclear extinction, centered on the holocaust itself, now has turned to the more terrifying consequences of a post-war nuclear winter: ''the long-term effects - destruction of the environment, spread of epidemic diseases, contamination by radioactivity, and ... collapse of agriculture-(that) would spread famine and death to every country.'' Nuclear Winter, the latest in a series of studies by a number of different groups is clinical, analytical, systematic, and detailed. Two physicists and biologist analyze the effects on the climate, plants, animals, and living systems; the human costs; the policy implications.

Greene, O.

1985-01-01

329

Estimates of Heterosis among Temperate, Subtropical and Tropical Maize Germplasm  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective was to assess the heterotic relationship among nine maize inbreds derived from temperate, subtropical and tropical material. The nine inbreds and their diallel crosses excluding reciprocals were evaluated for eleven biometric traits viz., days to pollen shedding, plant height, leaves plantG1, leaf area, ears plantG1, ear weight, grain moisture at harvest, kernel rows earG1, kernels rowG1, 100-kernel weight and grain yield. High heterotic effects were observed for plant height, e...

Malik, H. N.; Malik, S. I.; Chughtai, S. R.; Javed, H. I.

2004-01-01

330

Tempering chamber for preparation of atomically pure surfaces  

International Nuclear Information System (INIS)

The chamber consists of two telescopically arranged tubes. The fixed tube is provided with a piezoelectric resonator for evaporated particle display. A thermocouple is flexibly attached to the movable tube which, when the tube is slipped on a rotary manipulator with the sample, is in flexible contact with the sample surface. The movable tube is supported with an arm operated through a rotary bushing in the wall of the vacuum chamber recipient. The axes of analysis systems (coaxial Auger analyzer, LEED optics) and the tempering chamber axis lie in the plane of the sample to be studied. (H.S.)

1979-01-01

331

Resolutions of tempered representations of reductive p-adic groups  

CERN Document Server

Let G be a reductive group over a non-archimedean local field and let S(G) be its Schwartz algebra. We compare Ext-groups of tempered G-representations in several module categories: smooth G-representations, algebraic S(G)-modules, bornological S(G)-modules and an exact category of S(G)-modules on LF-spaces which contains all admissible S(G)-modules. We simplify the proofs of known comparison theorems for these Ext-groups, due to Meyer and Schneider-Zink. Our method is based on the Bruhat-Tits building of G and on analytic properties of the Schneider-Stuhler resolutions.

Opdam, Eric

2012-01-01

332

Discovering the importance of lateral CO2 transport from a temperate spruce forest  

International Nuclear Information System (INIS)

Our study investigated the concentration of dissolved carbon at the point when water leaves the pedosphere and whether this amount represents a significant proportion of terrestrial carbon cycling. The investigations were carried out in a temperate forest catchment (Black Forest, Germany) over a period of 1 year. The annual export of dissolved C compounds (14.4 g C m-2 year-1) was dominated by CO2 (9.7 vs. 4.7 g C m-2 year-1 DOC). Even though the direct CO2 degassing at the spring was inferior (0.4 kg C year-1), considerably lower CO2 concentrations were measured 17 m downstream of the spring. This shows that a large proportion of dissolved CO2 (93%) originating from the pedosphere is not captured anymore within a short distance from the spring. The measured lateral C-transport was in the same order of magnitude as reported for the net ecosystem exchange (NEE) observed for German spruce forests (-4 to -55 g C m-2 year-1). Therefore, the results clearly demonstrated that the lateral transport of dissolved carbon can be a significant part of terrestrial carbon budgets and for this study site CO2 was dominating this 'indirect' pathway. However, for generalisation, it is important to extend this investigation to other landscapes and climatic zones. (author)

2006-09-15

333

Simulating the carbon balance of a temperate larch forest under various meteorological conditions  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Changes in the timing of phenological events may cause the annual carbon budget of deciduous forests to change. Therefore, one should take such events into account when evaluating the effects of global warming on deciduous forests. In this article, we report on the results of numerical experiments done with a model that includes a phenological module simulating the timing of bud burst and other phenological events and estimating maximum leaf area index. Results This study suggests that the negative effects of warming on tree productivity (net primary production outweigh the positive effects of a prolonged growing season. An increase in air temperature by 3°C (5°C reduces cumulative net primary production by 21.3% (34.2%. Similarly, cumulative net ecosystem production (the difference between cumulative net primary production and heterotrophic respiration decreases by 43.5% (64.5% when temperatures are increased by 3°C (5°C. However, the positive effects of CO2 enrichment (2 × CO2 outweigh the negative effects of warming ( Conclusion Although the model was calibrated and validated for a specific forest ecosystem, the implications of the study may be extrapolated to deciduous forests in cool-temperate zones. These forests share common features, and it can be conjectured that carbon stocks would increase in such forests in the face of doubled CO2 and increased temperatures as long as the increase in temperature does not exceed 5°C.

Watanabe Tsutomu

2007-05-01

334

Apparent climatically induced increase of tree mortality rates in a temperate forest  

Science.gov (United States)

We provide a first detailed analysis of long-term, annual-resolution demographic trends in a temperate forest. After tracking the fates of 21 338 trees in a network of old-growth forest plots in the Sierra Nevada of California, we found that mortality rate, but not the recruitment rate, increased significantly over the 22 years of measurement (1983-2004). Mortality rates increased in both of two dominant taxonomic groups (Abies and Pinus) and in different forest types (different elevational zones). The increase in overall mortality rate resulted from an increase in tree deaths attributed to stress and biotic causes, and coincided with a temperature-driven increase in an index of drought. Our findings suggest that these forests (and by implication, other water-limited forests) may be sensitive to temperature-driven drought stress, and may be poised for die-back if future climates continue to feature rising temperatures without compensating increases in precipitation. ?? 2007 Blackwell Publishing Ltd/CNRS.

Van Mantgem, P. J.; Stephenson, N. L.

2007-01-01

335

Invasion of Nostocales (cyanobacteria to subtropical and temperate freshwater lakes – Physiological, regional and global driving forces  

Directory of Open Access Journals (Sweden)

Full Text Available Similarly to the increased number of studies on invasive plants and animals in terrestrial and aquatic ecosystems, many reports were recently published on the invasion of Nostocales (cyanobacteria to freshwater environments worldwide. Invasion and proliferation of Nostocales in new habitats have the potential to significantly alter the structure of native community and to modify ecosystem functioning. But most importantly, they influence the water quality due to a variety of toxic compounds that some species produce. Therefore a special attention was given to the invasion and persistence of toxic cyanobacteria in many aquatic ecosystems. Here we summarize the currently published records on the invasion of two Nostocales genera, Cylindrospermopsis and Aphanizomenon, to lakes and water reservoirs in subtropical and temperate zones. These invading species possess traits thought to be common to many invasive organisms: high growth rate, high resource utilization efficiency and overall superior competitive abilities over native species when local conditions vary. Assuming that dispersion routes of cyanobacteria have not been changed much in recent decades, their recent establishment and proliferation in new habitats indicate changes in the environment under which they can exploit their physiological advantage over the native phytoplankton population. In many cases global warming was identified as the major driving force for the invasion of Nostocales. Due to this uncontrollable trend, invasive Nostocales species are expected to maintain their presence in new habitats and further expand to new environments. In other cases regional changes in nutrient loads and in biotic conditions were attributed to the invasion events

AssafSukenik

2012-03-01

336

Comparative analysis of radiosensitivity of fish eggs from northern and temperate climate  

Energy Technology Data Exchange (ETDEWEB)

In the radiobiological studies of aquatic organisms, fish eggs are the favorite subject for experimental work because of easy availability of embryos and the possibility of observing the development of embryos within eggs. Data from Russian/FSU publications concerning the effects of ionizing radiation on fish eggs were compiled in the EPIC database within the framework of the EC Project EPIC. The comparative analysis of radiosensitivity was performed for eggs of two representative fish species from different climatic zones: cold water salmon (Salmo salar), and pike (Esox lucius), a widespread predatory fish in the temperate climate. A special attention was given to data of chronic exposure experiments with incubation of roe in water containing radionuclides. Dose rates on the fish eggs were estimated using appropriate dosimetric methodologies. Dose-effects relationships were constructed for chronic exposures during the periods of fish eggs development. The comparative analysis revealed that effects of ionizing radiation on salmon eggs appeared at lower doses than the effects on pike eggs. For example, first effects on survival of salmon eggs appeared at dose rate (1-2)*10-4 Gy/day, whereas effects on survival of pike eggs were not found at dose rates lower than (5-10)*10-3 Gy/day (chronic exposure); practically total death of roe took place at the chronic dose rates 0.13-0.33 Gy/day for salmon and 0.94 Gy/day for pike. Data on dose-effects relationships for salmon and pike roe defined the range of radiosensitivities between fish species from zones of severe and moderate climate. (author)

Kryshev, A.; Sazykina, T. [Scientific anf Production Association Typhoon, Obninsk, Kaluga Region (Russian Federation)

2004-07-01

337

Recent carbonate sedimentation on Balearic platform: model for temperate-climate carbonate shelves  

Energy Technology Data Exchange (ETDEWEB)

Existing models for carbonate sedimentation on continental platforms are derived from the study of modern carbonate platforms in tropical climates. The Balearic platform in the western Mediterranean provides a new model for carbonate sedimentation in a temperature, semiarid climate. On most of the continental shelf around the Balearic Islands, modern sediments are exclusively bioclastic carbonates. Shoreline carbonate sediments are bioclastic sands and muds accumulating in beach-dune systems without significant tidal influence (there are no astronomical tides in the western Mediterranean ). From the upper shoreface to 35 m deep, the sandy bottom is extensively colonized by sea grass (Posidonia oceanica), the rhizomes and roots of which form a rigid entrapment that retains the sediment derived from calcareous organisms living within the sea grass and from calcareous epiphytes living on the stems and leaves. Archeological dating establishes a rate of vertical accretion in this zone of 10/sup 3/ Bubnoff units (1 Bubnoff unit = 1 mm/1000 years). Between depths of 40 and 60 m, carbonate sands are composed predominantly or red-algal fragments. Intensely bioturbated wave ripples occur in environments dominated by laminar red algae (Lithothamnium and Phymatolithon). Below depths of 60 m, coarse sediment produced by rhodolitic and ramose red algae is deposited in areas of tens to hundreds of meters in size. Biogenic buildups up to 2 m high occur in sandy areas as well as in deeper muddy areas. At the same depth in open-platform zones, the bottom topography is characterized by large hummocks several hundred meters across. From the horizontal distribution of facies, it is possible to construct the probable vertical sequence of lithofacies which would characterize carbonates accumulating on a temperate-climate carbonate shelf. Many of these lithofacies are recognized in upper Miocene limestones on the Balearic Islands.

Fornos, J.; Rodriguez-Perea, A.; Massuti, C.; Pomar, L.; Acosta, J.; Herranz, P.; Sanz, J.L.

1989-03-01

338

Comparative analysis of radiosensitivity of fish eggs from northern and temperate climate  

International Nuclear Information System (INIS)

In the radiobiological studies of aquatic organisms, fish eggs are the favorite subject for experimental work because of easy availability of embryos and the possibility of observing the development of embryos within eggs. Data from Russian/FSU publications concerning the effects of ionizing radiation on fish eggs were compiled in the EPIC database within the framework of the EC Project EPIC. The comparative analysis of radiosensitivity was performed for eggs of two representative fish species from different climatic zones: cold water salmon (Salmo salar), and pike (Esox lucius), a widespread predatory fish in the temperate climate. A special attention was given to data of chronic exposure experiments with incubation of roe in water containing radionuclides. Dose rates on the fish eggs were estimated using appropriate dosimetric methodologies. Dose-effects relationships were constructed for chronic exposures during the periods of fish eggs development. The comparative analysis revealed that effects of ionizing radiation on salmon eggs appeared at lower doses than the effects on pike eggs. For example, first effects on survival of salmon eggs appeared at dose rate (1-2)*10-4 Gy/day, whereas effects on survival of pike eggs were not found at dose rates lower than (5-10)*10-3 Gy/day (chronic exposure); practically total death of roe took place at the chronic dose rates 0.13-0.33 Gy/day for salmon and 0.94 Gy/day for pike. Data on dose-effects relationships for salmon and pike roe defined the range of radiosensitivities between fish species from zones of severe and moderate climate. (author)

2004-09-06

339

Monitoring over-winter soil water dynamics in a freezing and snow-covered environment using a thermally insulated tensiometer  

Science.gov (United States)

Water potential below a frozen soil layer was continuously monitored over an entire winter period (using thermally insulated tensiometers sheltered in a heated chamber) along with other soil, snow and atmospheric variables. In early winter, the freezing front advanced under a thin snow cover, inducing upward soil water flow in the underlying unfrozen soil. The freezing front started to retreat when the snow cover became thick enough to insulate the soil, resulting in the reversal of the flow direction in the unfrozen zone. These data provide a clear illustration of soil water dynamics, which have rarely been monitored with a tensiometer.

Iwata, Yukiyoshi; Hirota, Tomoyoshi

2005-10-01

340

Winter Fatigue and Winter Depression : Prevalence and Treatment with Bright Light  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this thesis is to study prevalence of winter depressive mood and treatment effects of bright light for persons with winter fatigue and winter depression. Study I is a cross-sectional survey of a random sample (N=1657) from the general population between 18-65 years of age in Dalarna, Sweden (latitude 60°N). Study II is a similar survey of 17-18 year old students (N=756) in the municipality of Falun. Approximately 20% of both samples report seasonal symptoms, mainly fatigue, lowere...

Rastad, Cecilia

2009-01-01

 
 
 
 
341

Spearfishing to depletion: evidence from temperate reef fishes in Chile.  

Science.gov (United States)

Unreliable and data-poor marine fishery landings can lead to a lack of regulatory action in fisheries management. Here we use official Chilean landing reports and non-conventional indicators, such as fishers' perceptions and spearfishing competition results, to provide evidence of reef fishes depletions caused by unregulated spearfishing. Results show that the three largest and most emblematic reef fishes targeted mainly by spearfishers (> 98% of landings) [Graus nigra (vieja negra), Semicossyphus darwini (sheephead or pejeperro), and Medialuna ancietae (acha)] show signs of depletion in terms of abundance and size and that overall the catches of reef fishes have shifted from large carnivore species toward smaller-sized omnivore and herbivore species. Information from two snorkeling speargun world championships (1971 and 2004, Iquique, Chile) and from fishers' perceptions shows the mean size of reef fish to be declining. Although the ecological consequences of reef fish depletion are not fully understood in Chile, evidence of spearfishing depleting temperate reef fishes must be explicitly included in policy debates. This would involve bans or strong restrictions on the use of SCUBA and hookah diving gear for spearfishing, and minimum size limits. It may also involve academic and policy discussions regarding conservation and fisheries management synergies within networks of no-take and territorial user-rights fisheries areas, as a strategy for the sustainable management of temperate and tropical reef fisheries. PMID:20945755

Godoy, Natalio; Gelcich, L Stefan; Vásquez, Julio A; Castilla, Juan Carlos

2010-09-01

342

Metallurgical basis of producing continuous-annealed low temper tinplate  

Energy Technology Data Exchange (ETDEWEB)

Continuous-annealed, Al-killed, low temper tinplate, which has less surface enrichment of alloying element and uniform mechanical properties, superior to batch-annealed ones, has been manufactured. Some metallurgical points are different from continuous-annealed deep drawable steel. For avoiding deterioration of corrosion resistance, high temperature coiling in hot rolling cannot be applied for continuous annealing of tinplate. Higher cooling rate is, of course, preferable, but not important, because generally tinplate has smaller grains and many undissolved carbides, which results in less supersaturation of solute carbon and little carbide nucleation in a grain, even after rapid cooling and subsequent over-aging. Therefore, the kinetics of solute carbon change strongly depends upon grain sizes and the dispersion of carbides. The minimum hardness was obtained around 0.04%C for an over-aging cycle but 0.06% for a simple cooling cycle. The utilization of an extra-low-carbon steel for the production of low temper tinplate with non-aging property is also discussed.

Obara, T.; Sakata, K.; Osawa, K.; Nishida, M.; Irie, T. (Kawasaki Steel Corporation, Chiba (Japan))

343

Type 1,1-operators on spaces of temperate distributions  

DEFF Research Database (Denmark)

This paper is a follow-up on the authorâ??s general definition of pseudo-differential operators of type 1,1, in Hörmanderâ??s sense. It is shown that such operators are always defined on the smooth functions that are temperate; and moreover are defined and continuous on the space of temperate distributions, whenever they fulfil the twisted diagonal condition of Hörmander, or more generally when they belong to the self-adjoint subclass. Continuity in Lp -Sobolev spaces and Hölderâ??Zygmund spaces, and more generally in Besov and Lizorkinâ??Triebel spaces, is for positive smoothness also proved on the basis of the definition. These continuity results are extended to arbitrary real smoothness indices for operators that fulfil the twisted diagonal condition or belong to the self-adjoint subclass. With systematic Littlewoodâ??Paley analysis the well-known paradifferential decomposition is also derived for type 1,1-operators. The proofs are based on a spectral support rule for pseudo-differential operators in combination with pointwise estimates in terms of maximal functions.

Johnsen, Jon

2010-01-01

344

Gravitational tempering in colloidal epitaxy to reduce defects further  

CERN Document Server

Less-defective colloidal crystals can be used as photonic crystals. To this end, colloidal epitaxy was proposed in 1997 as a method to reduce the stacking defects in the colloidal crystals. In this method, face-centered cubic (fcc) (001) stacking is forced by a template. In fcc (001) stacking, in contract to fcc {111} stacking, the stacking sequence is unique and thus the stacking fault can be avoided. Additionally, in 1997, an effect of gravity that reduces the stacking disorder in hard-sphere (HS) colloidal crystals was found. Recently, we have proposed a gravitational tempering method based on a result of Monte Carlo (MC) simulations using the HS model; after a colloidal crystal is grown in a relatively strong gravitational field, the defects can be reduced by decreasing the gravity strength and maintain for a period of time. Here, we demonstrate this method using MC simulations with a programed gravitation. The dramatic disappearance of defect structures is observed. Gravitational tempering can complement...

Mori, Atsushi; Sato, Masahide

2014-01-01

345

Music Activities for Lemonade in Winter  

Science.gov (United States)

"Lemonade in Winter: A Book About Two Kids Counting Money" is a children's book about math; however, when sharing it in the music classroom, street cries and clapping games emerge. Jenkins' and Karas' book provides a springboard to lessons addressing several music elements, including form, tempo, and rhythm, as well as…

Cardany, Audrey Berger

2014-01-01

346

RoeAutumnWinterWildlifeWEB.indd  

Roe Valley Country Park Wildlife in Autumn and Winter Resource Book for Key Stage 2 Pupils Roe Valley Country Park www.ehsni.gov.uk 1 Introduction This booklet has been prepared for use as notes for teachers of KS2 ...

347

Winter chemistry of North Slope lakes  

Science.gov (United States)

Lakes are important water resources on the North Slope of Alaska. Oilfield exploration and production requires water for facility use as well as transportation. Ice road construction requires winter extraction of fresh water. Since most North Slope lakes are relatively shallow, the quantity and quality of the water remaining under the ice by the end of the winter are important environmental management issues. Currently permits are based on the presence of overwintering fish populations and their sensitivity to low oxygen. Sampling during the winter of 2004 2005 sheds light on the winter chemistry of several pumped lakes and one unpumped lake on the North Slope. Dissolved oxygen, conductivity, pH, and temperature profiles were taken along with ice thickness and water depth measurements. Water samples were extracted and analyzed for Na, Ca, K, Mg, Fe, DOC, and alkalinity in the laboratory. Lake properties, rather than pumping activities, were the best predictors of oxygen depletion, with the highest levels of dissolved oxygen maintained in the lake with the least dissolved constituents. As would be expected, specific conductance increased with depth in the lake while dissolved oxygen decreased with depth. Dissolved oxygen and specific conductance data suggested that the lakes began to refresh in May. The summarized data provides a view of North Slope lake chemistry trends, while continued studies investigate the chemical impacts of pumping North Slope lakes through continued sampling and modeling efforts.

Chambers, M. K.; White, D. M.; Lilly, M. R.; Hinzman, L. D.; Hilton, K. M.; Busey, R.

2006-12-01

348

The median winter snowline in the Alps  

Energy Technology Data Exchange (ETDEWEB)

The relative duration of snow cover in a season is a number between zero and unity; here it represents the probability to encounter, at a given station, snow of at least 5 cm depth. We use routine station data of snow depth for the winters 1961-2000 to explore the pattern of relative snow duration in the Alps. A horizontal isoline is drawn across all stations that exhibit 50 % snow duration; we consider this isoline the median snowline. We further introduce the mountain temperature as linear expansion of the Central European temperature with respect to station coordinates; it separates the large-scale European temperature from the local-scale vertical lapse rate and serves as substitute for the station temperature. The mountain temperature allows to condense the snow data of all stations and years into one analytical curve, the state function of snow duration. This curve yields every desired snowline; the median snowline coincides with the altitude of maximum sensitivity of snow duration to European temperature. The median snowline in winter is located at an average altitude of 641 m and slightly slopes downward towards the eastern Alps. The average altitude varies considerably from winter to winter under the influence of European temperature fluctuations; it shifts upward by about 123 m per C climate warming. (orig.)

Hantel, Michael; Maurer, Christian [Vienna Univ. (Austria). Research Platform ' ' Sensitive Mountain Limits of Snow and Vegetation' '

2011-06-15

349

Nuclear winter - Physics and physical mechanisms  

Science.gov (United States)

The basic physics of the environmental perturbations caused by multiple nuclear detonations is explored, summarizing current knowledge of the possible physical, chemical, and biological impacts of nuclear war. Emphasis is given to the impact of the bomb-generated smoke (soot) particles. General classes of models that have been used to simulate nuclear winter are examined, using specific models as examples.

Turco, R. P.; Toon, O. B.; Pollack, J. B.; Ackerman, T. P.; Sagan, C.

1991-01-01

350

Resonance asymptotics in the generalized Winter model  

International Nuclear Information System (INIS)

We consider a modification of the Winter model describing a quantum particle in presence of a spherical barrier given by a fixed generalized point interaction. It is shown that the three classes of such interactions correspond to three different types of asymptotic behaviour of resonances of the model at high energies

2006-12-18

351

Resonance asymptotics in the generalized Winter model  

Energy Technology Data Exchange (ETDEWEB)

We consider a modification of the Winter model describing a quantum particle in presence of a spherical barrier given by a fixed generalized point interaction. It is shown that the three classes of such interactions correspond to three different types of asymptotic behaviour of resonances of the model at high energies.

Exner, Pavel [Nuclear Physics Institute, Czech Academy of Sciences, 25068 Rez (Czech Republic) and Doppler Institute, Czech Technical University, Brehova 7, 11519 Prague (Czech Republic)]. E-mail: exner@ujf.cas.cz; Fraas, Martin [Nuclear Physics Institute, Czech Academy of Sciences, 25068 Rez (Czech Republic); Doppler Institute, Czech Technical University, Brehova 7, 11519 Prague (Czech Republic)

2006-12-18

352

Resonance asymptotics in the generalized Winter model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We consider a modification of the Winter model describing a quantum particle in presence of a spherical barrier given by a fixed generalized point interaction. It is shown that the three classes of such interactions correspond to three different types of asymptotic behaviour of resonances of the model at high energies.

Exner, Pavel; Fraas, Martin

2006-01-01

353

Stay Safe and Healthy This Winter!  

Centers for Disease Control (CDC) Podcasts

In this podcast for kids, the Kidtastics offer some simple ways to stay safe and healthy during the winter holiday season.  Created: 11/23/2010 by CDC Office of Womenâ??s Health.   Date Released: 11/23/2010.

2010-11-23

354

Impact of warm winters on microbial growth  

Science.gov (United States)

Growth of soil bacteria has an asymmetrical response to higher temperature with a gradual increase with increasing temperatures until an optimum after which a steep decline occurs. In laboratory studies it has been shown that by exposing a soil bacterial community to a temperature above the community's optimum temperature for two months, the bacterial community grows warm-adapted, and the optimum temperature of bacterial growth shifts towards higher temperatures. This result suggests a change in the intrinsic temperature dependence of bacterial growth, as temperature influenced the bacterial growth even though all other factors were kept constant. An intrinsic temperature dependence could be explained by either a change in the bacterial community composition, exchanging less tolerant bacteria towards more tolerant ones, or it could be due to adaptation within the bacteria present. No matter what the shift in temperature tolerance is due to, the shift could have ecosystem scale implications, as winters in northern Europe are getting warmer. To address the question of how microbes and plants are affected by warmer winters, a winter-warming experiment was established in a South Swedish grassland. Results suggest a positive response in microbial growth rate in plots where winter soil temperatures were around 6 °C above ambient. Both bacterial and fungal growth (leucine incorporation, and acetate into ergosterol incorporation, respectively) appeared stimulated, and there are two candidate explanations for these results. Either (i) warming directly influence microbial communities by modulating their temperature adaptation, or (ii) warming indirectly affected the microbial communities via temperature induced changes in bacterial growth conditions. The first explanation is in accordance with what has been shown in laboratory conditions (explained above), where the differences in the intrinsic temperature relationships were examined. To test this explanation the temperature relationships of the bacterial community from winter-warmed plots and plots with ambient soil temperatures were compared. No change in optimum temperature for growth could be detected, indicating that the microbial community has not been warm-adapted. This fits with what was seen also in the laboratory experiment where no changes in temperature response occurred when exposing bacteria to temperatures below 10 °C within two months. The increase in activity measured during winter should thereby be due to changes in environmental factors, which will be further investigated. One big difference between heated and control plots was that heated plots were snow free during the entire winter, while control plots were covered by a 10 cm snow cover. The plant community composition and flowering time also differed in the warmed and ambient plot.

Birgander, Johanna; Rousk, Johannes; Axel Olsson, Pål

2014-05-01

355

Modeling shoot water contents in high-elevation Picea rubens during winter.  

Science.gov (United States)

During the winter of 1990-1991, a meteorological tower was established at an 880-m elevation site within the spruce-fir zone on Mt. Moosilauke, New Hampshire, USA. Hourly means of air, needle and trunk temperatures, wind velocity, relative humidity and solar radiation were recorded. On a weekly basis, shoots that had elongated during the preceding growing season were collected from four red spruce (Picea rubens Sarg.) trees and their relative water contents (RWC) determined. Cuticular resistances of needles from these shoots were measured four times during the winter.Measured meteorological parameters were used in a previously developed model to simulate changes in red spruce shoot RWC during the winter. The modeled results were compared to measured shoot RWCs. The predictive power of the model was improved when it was modified to include measured values of cuticular resistance and needle and trunk temperatures. The new version of the model accurately predicted RWC from late December 1990 to the beginning of April 1991, after which spring recharge appeared to occur. We conclude that water lost from foliage was easily replaced by stored reserves and that uptake of water by the roots was not required to maintain an adequate foliar water content during the winter. PMID:14969940

Boyce, R L; Friedland, A J; Macdonald, V N

1992-12-01

356

Effect of tempering temperature on microstructure and mechanical properties of high boron white cast iron  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of different tempering temperatures on the microstructure and mechanical properties of air-quenched high boron white cast iron was studied. The results indicate that the high boron white cast iron comprises dendritic matrix and inter-dendritic M2B boride; and the matrix comprises martensite and pearlite. After quenching in the air, the matrix is changed into lath martensite; but only 1-?m-size second phase exists in the matrix. After tempering, another second phase of several tens of nanometers is found in the matrix, and the size and quantity increase with an increase in tempering temperature. The two kinds of second precipitation phase with different sizes in the matrix have the same chemical formula, but their forming stages are different. The precipitation phase with larger size forms during the austenitizing process, while the precipitation phase with smaller size forms during the tempering process. When tempered at different temperatures after quenching, the hardness decreases with an increase in the tempering temperature, but it increases a little at 450 ? due to the precipitation strengthening effect of the second phase, and it decreases greatly due to the martensite decomposition above 450 ?. The impact toughness increases a little when tempered below 300 ?, but it then decreases continuously owing to the increase in size and quantity of the secondary precipitate above 300 ?. Considered comprehensively, the optimum tempering temperature is suggested at 300 ? to obtain a good combination of hardness and toughness.

Liu Zhongli

2012-11-01

357

The Influence of Structural Parameters on the Yield Strength of Tempered Martensite and Lower Bainite.  

Science.gov (United States)

The contributions to the yield strength of tempered martensitic and bainitic structures was examined in 4340 steel. The principal factors that contribute to the reduction in yield strength with tempering in the range from 600 to 1000F are carbide coarseni...

D. W. Smith R. F. Hehemann

1970-01-01

358

On microstructure and performance of tempered high-boron high-speed steel roll  

Directory of Open Access Journals (Sweden)

Full Text Available Influences of the tempering temperature on the microstructure, mechanical property and wear resistance of High-Boron High Speed Steel (HBHSS roll materials were investigated by means of optical microscopy, scanning electron microscopy (SEM, X-ray diffraction, hardness measurement, impact tester, tensile tester and pin abrasion tester. The results show that the as-cast structure of HBHSS consists of a great amount of martensite and M2(B,C and a few retained austenites and M23(B,C6. After solution treated at 1,050 °C and followed by oil cooling, the amount of M23(B,C6 carbo-borides in quenched HBHSS increases obviously and the macrohardness of the quenched HBHSS is 66 HRC, which is very close to the 65.8 HRC of as-cast HBHSS. On the whole, the hardness of HBHSS alloy shows a trend of slight decrease with increasing tempering temperature when tempered below 500 °C. While when above 500 °C, the hardness increases slightly as the tempering temperature increases and reaches a peak at 525 °C and then decreases obviously. The impact toughness of HBHSS has a tendency to increase as the tempering temperature increases. Tempering can improve the tensile strength and elongation of HBHSS, but a higher tempering temperature causes a slight decrease in both tensile strength and elongation. Excellent wear resistance can be obtained by tempering at 500 to 550 °C.

Fu Hanguang

2012-08-01

359

Toughness and austenite stability of modified 9Cr-1Mo welds after tempering  

International Nuclear Information System (INIS)

The influence of tempering treatments on toughness and austenite stability was conducted on modified 9Cr-1Mo welds. Deteriorated impact toughness was noticed for the welds tempered between 450 and 610 C for 1 h, in which the peak hardness and the lowest impact energy occurred at 540 C. The impact toughness of the welds increased rapidly at tempering temperatures above 680 C, and the associated fracture surface exhibited mainly dimple fractures for 750 C/1 h tempered welds, in contrast to quasi-cleavage for 540 C/1 h welds. Retained austenite at martensite interlath boundaries was found to be mechanically stabilized by transformation stresses in the welds tempered at lower temperatures. It could also be transformed to untempered martensite upon cooling if the stresses were relieved to a certain degree by proper selection of temperature and time combinations in tempering. For welds tempered at higher temperatures, e.g. 750 C, the elimination of transformation stresses and the isothermal transformation of retained austenite to ferrite proceeded simultaneously. As a result, no martensitic transformation upon cooling could be found for such welds. The transformation of austenite to untempered martensite would certainly contribute to the minimum toughness of the weld after being tempered at 540 C/1 h. (orig.)

2000-07-15

360

The effects of boro-tempering heat treatment on microstructural properties of ductile iron  

International Nuclear Information System (INIS)

In this study, the effects of boro-tempering heat treatment on microstructural properties of ductile iron were investigated. Test samples with dimensions of 10 x 10 x 55 mm were boronized at 900 oC for 1, 3 and 5 h and then tempered at four different temperatures (250, 300, 350 and 450 oC) for 1 h. Both optical microscopy and scanning electron microscopy were used to reveal the microstructural details of coating and matrix of boro-tempered ductile iron. X-ray diffraction was used to determine the constituents of the coating layer. The boride layer formed on the surface of boro-tempered ductile cast iron is tooth shape form and consisted of FeB and Fe2B phases. The thickness of boride layer increases as the boronizing time increases and tempering temperature decreases. Tempering temperature is more effective than boronizing time on the matrix structure. Boro-tempering heat treatment reduces the formation of lower and upper ausferritic matrix temperature according to classical austempering. This causes formation of upper ausferritic matrix in the sample when tempered at 300 oC. This is in contrast to general case which is the formation of lower ausferritic matrix via austempering at this temperature.

2011-03-01

 
 
 
 
361

Numerical Comparison of Wang-Landau Sampling and Parallel Tempering for Met-Enkephalin  

Science.gov (United States)

We compare the efficiency of two prominent techniques for simulation of complex systems: parallel tempering and Wang-Landau sampling. We show that both methods are of comparable efficiency but are optimized for different platforms. Parallel tempering should be chosen on multi-processor system while Wang-Landau sampling is easier to implement on a single-processor computer.

Junghans, C.; Hansmann, U. H. E.

362

Winter shelters in Finland. Preliminary investigation. Saeaesuojat. Esitutkimus  

Energy Technology Data Exchange (ETDEWEB)

The preliminary study of winter shelters is one part of the Kilpisjaervi test building project. Efforts were made to clarify the usability of winter shelters and to seek the factors influencing the use of winter shelters on building sites. The study presented also research topics relating to winter shelters. The acquisition of winter shelter to the building site is now primarily a question of cost. It is acquired if its use is economically profitable. According to most of the interviewed the use of winter shelter is profitable in winter building. It is even national-economically profitable particularly if it can reduce the number of the so-called frost days on the building site. The most general use of winter shelter on the building site is for protection against snow and frost. It enables work even in severe climatic conditions and ensures thus for its part that the work is on schedule independent of the weather. It protects against snow, frost, wind, rain and sun. On building site winter shelter is used as work and stock shelter. When used in a correct way, winter shelter saves building materials, shortens work time, improves the quality of the final result, makes work more meaningful and improves order and work safety on the building site. Research should be directed at the estimation of the economy of winter shelters, their product development, study of the accident reducing effect of winter shelters and work conditions when winter shelters and heaters are used.

Rantamaeki, J.; Kivijakola, P.

1988-02-15

363

Effects of elevated atmospheric CO2, prolonged summer drought and temperature increase on N2O and CH4 fluxes in a temperate heathland  

DEFF Research Database (Denmark)

In temperate regions, climate change is predicted to increase annual mean temperature and intensify the duration and frequency of summer droughts, which together with elevated atmospheric carbon dioxide (CO2) concentrations, may affect the exchange of nitrous oxide (N2O) and methane (CH4) between terrestrial ecosystems and the atmosphere. We report results from the CLIMAITE experiment, where the effects of these three climate change parameters were investigated solely and in all combinations in a temperate heathland. Field measurements of N2O and CH4 fluxes took place 1â??2 years after the climate change manipulations were initiated. The soil was generally a net sink for atmospheric CH4. Elevated temperature (T) increased the CH4 uptake by on average 10 μg C mâ??2 hâ??1, corresponding to a rise in the uptake rate of about 20%. However, during winter elevated CO2 (CO2) reduced the CH4 uptake, which outweighed the positive effect of warming when analyzed across the study period. Emissions of N2O were generally low (

Carter, Mette Sustmann; Ambus, Per

2011-01-01

364

Temporal and spatial heterogeneity in lacustrine ?13CDIC and ?18ODO signatures in a large mid-latitude temperate lake  

Directory of Open Access Journals (Sweden)

Full Text Available Modelling limnetic carbon processes is necessary for accurate global carbon models and stable isotope analysis can provide additional insight of carbon flow pathways. This research examined the spatial and temporal complexity of carbon cycling in a large temperate lake. Dissolved inorganic carbon (DIC is utilised by photosynthetic organisms and dissolved oxygen (DO is used by heterotrophic organisms during respiration. Thus the spatial heterogeneity in the pelagic metabolic balance in Loch Lomond, Scotland was investigated using a combined natural abundance isotope technique. The isotopic signatures of dissolved inorganic carbon (?13CDIC and dissolved oxygen (?18ODO were measured concurrently on four different dates between November 2004 and September 2005. We measured isotopic variation over small and large spatial scales, both horizontal distance and depth. ?13CDIC and ?18ODO changed over a seasonal cycle, becoming concurrently more positive (negative in the summer (winter months, responding to increased photosynthetic and respiratory rates, respectively. With increasing depth, ?13CDIC became more negative and ?18ODO more positive, reflecting the shift to a respiration-dominated system. The horizontal distribution of ?13CDIC and ?18ODO in the epilimnion was heterogeneous. In general, the south basin had the most positive ?13CDIC, becoming more negative with increasing latitude, except in winter when the opposite pattern was observed. Areas of local variation were often observed near inflows. Clearly ?13CDIC and ?18ODO can show large spatial heterogeneity, as a result of varying metabolic balance coupled with inflow proximity and thus single point sampling to extrapolate whole lake metabolic patterns can result in error when modelling large lake systems Whilst we advise caution when using single point representation, we also show that this combined isotopic approach has potential to assist in constructing detailed lake carbon models.

Jane DRUMMOND

2010-08-01

365

Mosquito Species Associated Within Some Western Himalayas Phytogeographic Zones in the Garhwal Region of India  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Thirty four species of mosquitoes (Diptera: Culicidae) were collected across three phytogeographic zones; tropical (300 to 1000 m), sub tropical (1000 to 2000 m) and temperate (2000 to 3000 m) in the Garhwal region of India. They included 5 genera: Aedes, Anopheles, Armigeres, Culex and Uranotaenia. Of these, the immature forms of 23 species were recovered from different breeding habitats. The larval habitats were seepage pools, river beds, rice fields, tanks, forest pools, ditches, streams, ...

Pemola Devi, N.; Jauhari, R. K.

2007-01-01

366

Effect of tempering on microstructure and mechanical properties of a non-quenched bainitic steel  

Energy Technology Data Exchange (ETDEWEB)

The effect of tempering on the microstructure and mechanical properties of a non-quenched (NQ) bainitic steel was investigated by optical microscopy, X-ray diffractometry, scanning electronic microscope (SEM) and transmission electronic microscopy (TEM). The results show that the NQ steel which has been investigated is granular bainite composed of bainitic ferrite lath, retained austenite film and island of austenite and martensite (M/A island) before tempering. The amount of retained austenite decreases with the rise of tempering, slowly before 400 deg. C, sharply at 450 deg. C, and it is close to 0 at 600 deg. C. When tempered at 350 deg. C, this kind of NQ steel has the optimum mechanical properties because of M/A islands partly decomposition, especially for the martensite in the M/A islands. However, when tempered at 450 deg. C, it appears brittleness, which results from carbides distributing along prior austenite grains because M/A island is largely decomposed.

Luo Yi, E-mail: luoyileyi@163.com [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China); Peng Jinmin; Wang Hongbin; Wu Xiaochun [School of Materials Science and Engineering, Shanghai University, Shanghai 200072 (China)

2010-06-15

367

Atom Probe Tomography Analysis of Precipitation during Tempering of a Nanostructured Bainitic Steel  

Science.gov (United States)

Carbon distribution during tempering of a nanostructured bainitic steel was analyzed by atom probe tomography (APT). Three different types of particles are detected on samples tempered at 673 K (400 °C) for 30 minutes: lower bainite cementite with a carbon content of ~25 at. pct, ?-carbides with a carbon content close to 30 at. pct, and carbon clusters, small features with a carbon content of ~14 at. pct indicative of a stage of tempering prior to precipitation of ?-carbide. After tempering at 773 K (500 °C) for 30 minutes, the ?-carbide-to-cementite transition was observed. Solute concentration profiles across carbide/ferrite interfaces showed the distribution of substitutional elements in ?-carbide and cementite for all the tempering conditions.

Caballero, F. G.; Miller, M. K.; Garcia-Mateo, C.

2011-12-01

368

Enhanced Mechanical Properties of a Hot-Stamped Advanced High-Strength Steel via Tempering Treatment  

Science.gov (United States)

The hot stamping process has an extensive range of applications due to its advantages over the traditionally used stamping techniques developed in the past. To enhance the mechanical properties of the indirectly hot-stamped parts, the quenching and partitioning (Q&P) process has been recently applied on boron-alloyed steel. In the current research, it was observed that the tempering treatment on the directly hot-stamped boron steel resulted in better mechanical properties and higher formability index compared with the reported results using the Q&P process. The nano-carbide formation and the dislocation annihilation during the tempering treatment were suggested as the evident reasons for the occurrence of the mentioned robust properties. The ease of the practical implementation of the tempering route together with the markedly enhanced mechanical properties of the tempered parts make the suggested method privileged. Additionally, the variations in the yield strength before and after tempering were quantitatively evaluated.

Naderi, M.; Abbasi, M.; Saeed-Akbari, A.

2013-04-01

369

Winter climate variability and classification in the Bulgarian Mountainous Regions  

International Nuclear Information System (INIS)

The problems of snowiness and thermal conditions of winters are of high interest of investigations because of the more frequent droughts, occurred in the region. In the present study an attempt to reveal tendencies existing during the last 70 years of 20 th century in the course winter precipitation and,temperature as well as in some of the snow cover parameters. On the base of mean winter air temperature winters in the Bulgarian mountains were analyzed and classified. The main results of the study show that winter precipitation has decrease tendencies more significant in the highest parts of the mountains. On the other hand winter air temperature increases. It shows a relatively well-established maximum at the end of the studied period. In the Bulgarian mountains normal winters are about 35-40% of all winters. (Author)

2004-05-25

370

Winter road access to projected works in the diversion of the Little Whale River  

International Nuclear Information System (INIS)

The Great Whale hydroelectric complex in northern Quebec will require diversion of the Little Whale River, involving construction of dams 40 m and 30 m high and a canal 600 m long. The main mode of access to the construction sites will be a winter road, supplemented by an airfield designed for large-capacity aircraft. The method used by Hydro-Quebec in its environmental assessment of the winter road project is described. This method comprises five steps: delimitation of the study zone; establishment of a road corridor of choice by successively eliminating territory according to given constraints; description of the physical and biological environment; determination and optimization of the road route; and evaluation of potential impacts, along with establishment of measures to mitigate those impacts. The optimal routing is determined on the basis of criteria such as the presence of permafrost, the nature of the soils, avoidance of slopes steeper than 10%, and the depth and width of ice crossings

1992-01-22

371

AGA predicts winter jump in residential gas price  

International Nuclear Information System (INIS)

The American Gas Association predicts the average heating bill for residential gas consumers could increase by as much as 18% this winter. AGA Pres. Mike Baly said, Last year's winter was warmer than normal. If the 1992-93 winter is similar, AGA projects that residential natural gas heating bills will go up about 6%. If we see a return to normal winter weather, our projection show the average bill could rise by almost 18%

1992-11-09

372

Effect of Tempering Time on Microstructure, Tensile Properties, and Deformation Behavior of a Ferritic Light-Weight Steel  

Science.gov (United States)

In the present study, a ferritic light-weight steel was tempered at 973 K (700 °C) for various tempering times, and tensile properties and deformation mechanisms were investigated and correlated to microstructure. ?-carbides precipitated in the tempered band-shaped martensite and ferrite matrix, and the tempered martensite became more decomposed with increasing tempering time. Tempering times for 3 days or longer led to the formation of austenite as irregular thick-film shapes mostly along boundaries between the tempered martensite and the ferrite matrix. Tensile tests of the 1-day-tempered specimen showed that deformation bands were homogeneously spread throughout the specimen, and that the fine carbides were sufficiently deformed inside these deformation bands resulting in high strength and ductility. The 3-day-tempered specimen showed a small amount of boundary austenite, which readily developed voids or cracks and became sites for fracture. This cracking at boundary austenites became more prominent in the 7- and 15-day-tempered specimens, as the volume fraction of boundary austenites increased with increasing tempering time. These findings suggested that, when the steel was tempered at 973 K (700 °C) for an appropriate time, i.e., 1 day, to sufficiently precipitate ?-carbides and to prevent the formation of boundary austenites, that the deformation occurred homogeneously, leading to overall higher mechanical properties.

Han, Seung Youb; Shin, Sang Yong; Lee, Byeong-Joo; Lee, Sunghak; Kim, Nack J.; Kwak, Jai-Hyun

2013-01-01

373

Standardized Precipitation Index Zones for México  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: English Abstract in spanish Existen varios sistemas de zonificación de México basados en la estacionalidad, cantidad de precipitación, climas y divisiones geográficas, pero ninguno es conveniente para el estudio de la relación de la precipitación con fenómenos tales como El Niño. En este trabajo se presenta un conjunto de siet [...] e zonas empíricas exclusivamente mexicanas y seis compartidas, derivadas de tres series de imágenes de SPI (Índice Estandarizado de la Precipitación), desde 1940 a 1989: una serie de 582 imágenes mensuales (SPI-12), una serie de 50 imágenes (SPI-6) de meses de invierno (noviembre a abril), y otra de 50 imágenes (SPI-6) de meses de verano (mayo a octubre). Al examinar imágenes de componentes principales y de clasificaciones no supervisadas, se descubrió que las tres series tenían una zonificación similar. Un conjunto de campos de entrenamiento fue utilizado para clasificar las tres series. Después de doce tanteos las zonas resultantes, presentadas aquí, fueron casi idénticas para las tres series, con variaciones principalmente alrededor de los bordes. Un conjunto de zonas sencillas definidas por pocos vértices puede ser usado para operaciones prácticas. En general, las zonas son homogéneas, casi sin mezcla de zonas y con pocos fragmentos de una zona en otra. Estas zonas se comparan con un mapa previamente publicado de zonas climáticas. Se mencionan posibles aplicaciones. Abstract in english Precipitation zone systems exist for México based on seasonality, quantity of precipitation, climates and geographical divisions, but none are convenient for the study of the relation of precipitation with phenomena such as El Niño. An empirical set of seven exclusively Mexican and six shared zones [...] was derived from three series of Standardized Precipitation Index (SPI) images, from 1940 through 1989: a whole-year series (SPI-12) of 582 monthly images, a six month series (SPI-6) of 50 images for winter months (November through April), and a six-month series (SPI-6) of 50 images for summer months (May through October). By examination of principal component and unsupervised classification images, it was found that all three series had similar zones. A set of basic training fields chosen from the principal component images was used to classify all three series. The resulting thirteen zones, presented in this article, were found to be approximately similar, varying principally at zone edges. A set of simple zones defined by just a few vertices can be used for practical operations. In general the SPI zones are homogeneous, with almost no mixture of zones and few outliers of one zone in the area of others. They are compared with a previously published map of climatic regions. Potential applications for SPI zones are discussed

L., GIDDINGS; M., SOTO; B. M., RUTHERFORD; A., MAAROUF.

374

Latitudinal variation in population structure of wintering Pacific Black Brant  

Science.gov (United States)

Latitudinal variation in population structure during the winter has been reported in many migratory birds, but has been documented in few species of waterfowl. Variation in environmental and social conditions at wintering sites can potentially influence the population dynamics of differential migrants. We examined latitudinal variation in sex and age classes of wintering Pacific Black Brant (Branta bernicla nigricans). Brant are distributed along a wide latitudinal gradient from Alaska to Mexico during the winter. Accordingly, migration distances for brant using different wintering locations are highly variable and winter settlement patterns are likely associated with a spatially variable food resource. We used resightings of brant banded in southwestern Alaska to examine sex and age ratios of birds wintering at Boundary Bay in British Columbia, and at San Quintin Bay, Ojo de Liebre Lagoon, and San Ignacio Lagoon in Baja California from 1998 to 2000. Sex ratios were similar among wintering locations for adults and were consistent with the mating strategy of geese. The distribution of juveniles varied among wintering areas, with greater proportions of juveniles observed at northern (San Quintin Bay and Ojo de Liebre Lagoon) than at southern (San Ignacio Lagoon) locations in Baja California. We suggest that age-related variation in the winter distribution of Pacific Black Brant is mediated by variation in productivity among individuals at different wintering locations and by social interactions among wintering family groups. Journal compilation ??2007 Association of Field Ornithologists.

Schamber, J. L.; Sedinger, J. S.; Ward, D. H.; Hagmeier, K. R.

2007-01-01

375

Antarctic, Sub-Antarctic and cold temperate echinoid database  

Directory of Open Access Journals (Sweden)

Full Text Available This database includes spatial data of Antarctic, Sub-Antarctic and cold temperate echinoid distribution (Echinodermata: Echinoidea collected during many oceanographic campaigns led in the Southern Hemisphere from 1872 to 2010. The dataset lists occurrence data of echinoid distribution south of 35°S latitude, together with information on taxonomy (from species to genus level, sampling sources (cruise ID, sampling dates, ship names and sampling sites (geographic coordinates and depth. Echinoid occurrence data were compiled from the Antarctic Echinoid Database (David et al., 2005a, which integrates records from oceanographic cruises led in the Southern Ocean until 2003. This database has been upgraded to take into account data from oceanographic cruises led after 2003. The dataset now reaches a total of 6160 occurrence data that have been checked for systematics reliability and consistency. It constitutes today the most complete database on Antarctic and Sub-Antarctic echinoids.

Benjamin Pierrat

2012-06-01

376

Influence of titanium on the tempering structure of austenitic steels  

International Nuclear Information System (INIS)

The microstructure of titanium-stabilized and initially deformed (approximately 20%) austenitic stainless steels used in structures of fast neutrons reactors has been studied after one hour duration annealings (500 <= T <= 800"0C) by X-ray diffraction, optical microscopy, microhardness and transmission electron microscopy. The studied alloys were either of industrial type CND 17-13 (0.23 to 0.45 wt% Ti) or pure steels (18% Cr, 14% Ni, 0 or 0.3 wt% Ti). During tempering, the pure steels presented some restauration before recristallization. In the industrial steels, only recristallization occurred, and this only in the most deformed steel. Precipitation does not occur in the titanium-free pure steel. In industrial steels, many intermetallic phases are formed when recristallization starts

1985-01-01

377

The Fracture Process of Tempered Soda-Lime-Silica Glass  

DEFF Research Database (Denmark)

This work presents experimental observations of the characteristic fracture process of tempered glass. Square specimens with a side length of 300 mm, various thicknesses and a residual stress state characterized by photoelastic measurements were used. Fracture was initiated using a 2.5 mm diamond drill and the fragmentation process was captured using High-Speed digital cameras. From the images, the average speed of the fracture front propagation was determined within an accuracy of 1.0%. Two characteristic fragments were found to form on each side of the initiation point and are named â??Whirl-fragmentsâ? referring to the way they are generated. An earlier estimation of the in-plane shape of the fracture front is corrected and a hypothesis on the development for the fracture front is offered. The hypothesis is supported by investigations of the fragments using a Scanning Electron Microscope (SEM) which also revealed a micro scale crack bridging effect.

Nielsen, Jens Henrik; Olesen, John Forbes

2009-01-01

378

Zoning in zircons  

International Nuclear Information System (INIS)

The TL emission in many zircons is zoned. Because regions of bright TL emission are anti-correlated with regions of high uranium content, age determination by conventional methods give TL dates which are too low. We designed an image intensifier based TL system capable of resolving features on a 5 micron scale during heating in order to detect zoned grains early in the dating procedure. Early rejection of zoned grains would have made the conventional dating approach feasible. However, although polished crystals can unambiguously be identified as being zoned from their TL images, untreated, whole crystals often have superficial features which tend to blur images of the internal zoned light emissions. (author)

1985-01-01

379

Sharp View of Gullies in Southern Winter  

Science.gov (United States)

20 November 2006 Crisp details in a suite of mid-latitude gullies on a crater wall are captured in this Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) view obtained in southern winter on 12 October 2006. During southern winter, shadows are more pronounced and the atmosphere is typically quite clear. These gullies, which may have formed in relatively recent martian history by erosion caused by flowing, liquid water, are located in a crater on the east rim of Newton Crater near 40.4oS, 155.3oW. Sunlight illuminates the scene from the upper left. The picture covers an area about 3 km (1.9 mi) wide; the crater rim is on the right side of the image, the crater floor is on the left. North is toward the top/upper left.

2006-01-01

380

Shallow stratigraphic control on pockmark distribution in north temperate estuaries  

Science.gov (United States)

Pockmark fields occur throughout northern North American temperate estuaries despite the absence of extensive thermogenic hydrocarbon deposits typically associated with pockmarks. In such settings, the origins of the gas and triggering mechanism(s) responsible for pockmark formation are not obvious. Nor is it known why pockmarks proliferate in this region but do not occur south of the glacial terminus in eastern North America. This paper tests two hypotheses addressing these knowledge gaps: 1) the region's unique sea-level history provided a terrestrial deposit that sourced the gas responsible for pockmark formation; and 2) the region's physiography controls pockmarks distribution. This study integrates over 2500 km of high-resolution swath bathymetry, Chirp seismic reflection profiles and vibracore data acquired in three estuarine pockmark fields in the Gulf of Maine and Bay of Fundy. Vibracores sampled a hydric paleosol lacking the organic-rich upper horizons, indicating that an organic-rich terrestrial deposit was eroded prior to pockmark formation. This observation suggests that the gas, which is presumably responsible for the formation of the pockmarks, originated in Holocene estuarine sediments (loss on ignition 3.5–10%), not terrestrial deposits that were subsequently drowned and buried by mud. The 7470 pockmarks identified in this study are non-randomly clustered. Pockmark size and distribution relate to Holocene sediment thickness (r2 = 0.60), basin morphology and glacial deposits. The irregular underlying topography that dictates Holocene sediment thickness may ultimately play a more important role in temperate estuarine pockmark distribution than drowned terrestrial deposits. These results give insight into the conditions necessary for pockmark formation in nearshore coastal environments.

Brothers, Laura L.; Kelley, Joseph T.; Belknap, Daniel F.; Barnhardt, Walter A.; Andrews, Brian D.; Legere, Christine; Hughes-Clarke, John E.

2012-01-01

 
 
 
 
381

Induction and Properties of a Temperate Bacteriophage from Bacillus stearothermophilus  

Science.gov (United States)

Welker, N. E. (University of Illinois, Urbana), and L. Leon Campbell. Induction and properties of a temperate bacteriophage from Bacillus stearothermophilus. J. Bacteriol. 89:175–184. 1965.—Bacillus stearothermophilus 1503-4R growing at 55 C was induced to lyse either when 0.05 ?g/ml of mitomycin C was added or when it was exposed to ultraviolet light for 30 sec. Lysis of the induced cultures occurred 45 to 60 min after induction. Phage were assayed on B. stearothermophilus 4S giving turbid plaques 0.05 to 0.3 cm in diameter. Noninduced cultures of 1503-4R spontaneously produced one phage per 2.8 × 106 bacterial cells. The optimal temperature for phage production and assay was found to be 55 C. B. stearothermophilus 1503-4R was immune to the isolated temperate phage (TP-1) and to a clear-plaque mutant phage (TP-1C), even when tested at phage mutliplicities of 100. TP-1 and TP-1C phage were identical morphologically having a head 65 m? in diameter and a tail 240 m? long and 12 m? wide. TP-1C phage deoxyribonucleic acid (DNA) had an S20,w value of 24.1 and a calculated molecular weight of 1.21 × 107. DNA base compositions of TP-1 and TP-1C phage were identical (42% guanine + cytosine), but differed significantly from those of the lysogenic or indicator strains of B. stearothermophilus (50% guanine + cytosine). No unusual bases were detected in either the bacterial or phage DNA. Images

Welker, N. E.; Campbell, L. Leon

1965-01-01

382

Influence of tempering on mechanical properties of ferritic martensitic steels  

Energy Technology Data Exchange (ETDEWEB)

In the mid-1980s research programs for development of low activation materials began. This is based on the US Nuclear Regulatory Commission Guidelines (10CFR part 61) that were developed to reduce long-lived radioactive isotopes, which allows nuclear reactor waste to be disposed of by shallow land burial when removed from service. Development of low activation materials is also key issue in nuclear fusion systems, as the structural components can became radioactive due to nuclear transmutation caused by exposure to high dose neutron irradiation. Reduced-activation ferritic martensitic (RAFM) steels have been developed in the leading countries in nuclear fusion technology, and are now being considered as primary candidate material for the test blanket module (TBM) in the international thermonuclear experiment reactor (ITER). RAFM steels developed so far (e.g., EUROFER 97 and F82H) meet the requirement for structural application in the ITER. However, if such alloys are used in the DEMO or commercial fusion reactor is still unclear, as the reactors are designed to operate under much severe conditions (i.e., higher outlet coolant temperature and neutron fluences). Such harsh operating conditions lead to development of RAFM steels with better creep and irradiation resistances. Mechanical properties of RAFM steels are strongly affected by microstructural features including the distribution, size and type of precipitates, dislocation density and grain size. For a given composition, such microstructural characteristics are determined mainly by thermo-mechanical process employed to fabricate the final product, and accordingly a final heat treatment, i.e., tempering is the key step to control the microstructure and mechanical properties. In the present work, we investigated mechanical properties of the RAFM steels with a particular attention being paid to effects of tempering on impact and creep properties.

Chun, Y. B.; Han, C. H.; Choi, B. K.; Lee, D. W.; Kim, T. K.; Jeong, Y. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Cho, S. [National Fusion Research Institute, Daejeon (Korea, Republic of)

2012-10-15

383

Social implications of residential demand response in cool temperate climates  

International Nuclear Information System (INIS)

Residential electrical demand response (DR) offers the prospect of reducing the environmental impact of electricity use, and also the supply costs. However, the relatively small loads and numerous actors imply a large effort: response ratio. Residential DR may be an essential part of future smart grids, but how viable is it in the short to medium term? This paper reviews some DR concepts, then evaluates the propositions that households in cool temperate climates will be in a position to contribute to grid flexibility within the next decade, and that that they will allow some automated load control. Examples of demand response from around the world are discussed in order to assess the main considerations for cool climates. Different tariff types and forms of control are assessed in terms of what is being asked of electricity users, with a focus on real-time pricing and direct load control in energy systems with increasingly distributed resources. The literature points to the significance of thermal loads, supply mix, demand-side infrastructure, market regulation, and the framing of risks and opportunities associated with DR. In concentrating on social aspects of residential demand response, the paper complements the body of work on technical and economic potential. - Highlights: ? Demand response implies major change in governance of electricity systems. ? Households in cool temperate climates can be flexible, mainly with thermal loads. ? DR requires simple tariffs, appropriate enabling technology, education, and feedback. ? Need to test consumer acceptance of DR in specific conditions. ? Introduce tariffs with technologies e.g., TOU tariff plus DLC with electric vehicles.

2012-10-01

384

Measuring Transpiration to Regulate Winter Irrigation Rates  

Energy Technology Data Exchange (ETDEWEB)

Periodic transpiration (monthly sums) in a young loblolly pine plantation between ages 3 and 6 was measured using thermal dissipation probes. Fertilization and fertilization with irrigation were better than irrigation alone in increasing transpiration of young loblolly pines during winter months, apparently because of increased leaf area in fertilized trees. Irrigation alone did not significantly increase transpiration compared with the non-fertilized and non-irrigated control plots.

Samuelson, Lisa [Auburn University

2006-11-08

385

Soil and radiocaesium contamination of winter fodders  

International Nuclear Information System (INIS)

The level of 137Cs and soil contaminating three winter fodders was determined on organic and mineral soil and the effect of harvesting, fodder storage and weather conditions on the contamination level was assessed. The mean level of soil contamination in hay and silage was generally 137Cs content of all fodders were highly correlated indicating that, in this study, soil adhesion to plant surfaces is the main vector of 137Cs transfer

1994-07-15

386

Comparison of East Asian winter monsoon indices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Four East Asian winter monsoon (EAWM) indices are compared in this paper. In the research periods, all the indices show similar interannual and decadal-interdecadal variations, with predominant periods centering in 3–4 years, 6.5 years and 9–15 years, respectively. Besides, all the indices show remarkable weakening trends since the 1980s. The correlation coefficient of each two indices is positive with a significance level of 99%. Both the correlation analyses and the co...

Gao Hui

2007-01-01

387

Comparison of East Asian winter monsoon indices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Four East Asian winter monsoon (EAWM) indices are compared in this paper. In the research periods, all the indices show similar interannual and decadal-interdecadal variations, with predominant periods centering in 3?4 years, 6.5 years and 9?15 years, respectively. Besides, all t