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Sample records for winter temperate zone

  1. Biofloc production technology promising in temperate zones – Channel catfish perform during winter months

    A study was conducted to assess the feasibility to grow Channel catfish (Ictalurus punctatus) in an outdoor biofloc system during winter in a temperate zone. High biomasses of market-size channel catfish were successfully maintained through the winter with high survival and in good condition in both...

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

    An air radioactivity monitoring study carried out in Dalat, Vietnam since 1986 has revealed distinct peaks of caesium isotope concentrations in air and fallout during December-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 anti cyclones, frequently observed in the most active winter monsoon period. 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 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

  3. Winter disturbances and riverine fish in temperate and cold regions

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

    2013-01-01

    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 ...

  4. Rhizome starch as indicator for temperate seagrass winter survival

    Govers, L.L.; Suykerbuyk, W.; Hoppenreijs, J.; Giesen, K.; Bouma, T.J.; Katwijk, M.M. van

    2015-01-01

    Key-ecosystems such as seagrass beds are disappearing on a global scale. In order to counter-act local loss of seagrass beds, seagrass restoration projects have been carried out with varying degrees of success. As seagrass biomass peaks in summer, most restoration projects are monitored during this period, while wintering processes are largely ignored. We here attempted to elucidate some important bottlenecks for wintering survival in temperate areas of the intertidal model species Zostera no...

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

    J. Schuerings

    2014-06-01

    Full Text Available 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.

  6. Silicon pools in human impacted soils of temperate zones

    Vandevenne, F. I.; Barão, L.; Ronchi, B.; Govers, G.; Meire, P.; Kelly, E. F.; Struyf, E.

    2015-09-01

    Besides well-known effects of climate and parent material on silicate weathering the role of land use change as a driver in the global silicon cycle is not well known. Changes in vegetation cover have altered reservoirs of silicon and carbon in plants and soils. This has potential consequences for plant-Si availability, agricultural yields, and coastal eutrophication, as Si is a beneficial element for many crop plants and an essential nutrient for diatom growth. We here examined the role of sustained and intensive land use and human disturbance on silicon (Si) pool distribution in soils with similar climatological and bulk mineralogical characteristics. We show that land use impacts both biogenic and nonbiogenic Si pools. While biogenic Si strongly decreases along the land use change gradient (from forest to croplands), pedogenic silica fractions (e.g. pedogenic clays) increase in topsoils with a long duration of cultivation and soil disturbance. Our results suggest that nonbiogenic Si pools might compensate for the loss of reactive biogenic silicon in temperate zones.

  7. Winter warming delays dormancy release, advances budburst, alters carbohydrate metabolism and reduces yield in a temperate shrub

    Pagter, Majken; Andersen, Uffe Brandt; Andersen, Lillie

    2015-01-01

    ‘Titania’. Since ‘Narve Viking’ has a higher chilling requirement than ‘Titania’, this indicates that, in high-chillingrequiring genotypes, dormancy responses may temper the effect of warming on spring phenology. Winter Warming significantly reduced fruit yield the following summer in both cultivars...

  8. Establishing the breeding provenance of a temperate-wintering North American passerine, the Golden-crowned Sparrow, using light-level geolocation.

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

    2012-01-01

    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 used a bayesian state-space model to estimate the most likely breeding locations. All four birds spent the breeding season on the coast of the Gulf of Alaska. These locations spanned approximately 1200 kilometers, and none of the individuals bred in the same location. Speed of migration was nearly twice as fast during spring than fall. The return rate of birds tagged the previous season (33%) was similar to that of control birds (39%), but comparing return rates was complicated because 7 of 11 returning birds had lost their tags. For birds that we recaptured before spring migration, we found no significant difference in mass change between tagged and control birds. Our results provide insight into the previously-unknown breeding provenance of a wintering population of Golden-crowned Sparrows and provide more evidence of the contributions that light-level geolocation can make to our understanding of the migratory geography of small passerines. PMID:22506055

  9. Winter photosynthetic activity of twenty temperate semi-desert sand grassland species.

    Tuba, Zoltán; Csintalan, Zsolt; Szente, Kálmán; Nagy, Zoltán; Fekete, Gábor; Larcher, Walter; Lichtenthaler, Hartmut K

    2008-09-29

    The winter photosynthetic activity (quantified by net CO(2) assimilation rates and chlorophyll (Chl) a fluorescence parameters) of 20 plant species (including two lichens and two mosses) of a Hungarian temperate semi-desert sand grassland was determined on one occasion per year in 1984, 1989 and 1994. Throughout winter, the overwintering green shoots, leaves or thalli were regularly exposed to below zero temperatures at night and daytime temperatures of 0-5 degrees C. In situ tissue temperature varied between -2.1 and +6.9 degrees C and the photosynthetic photon flux density (PPFD) between 137 and 351 micromol m(-2)s(-1). Under these conditions 18 of the grassland species exhibited photosynthetic CO(2) uptake (range: vascular plants ca. 0.2-3.8 micromol m(-2)s(-1), cryptogams 0.3-2.79 micromol kg(-1)s(-1)) and values of 0.9-5.1 of the Chl fluorescence decrease ratio R(Fd). In 1984, Festuca vaginata and Sedum sexangulare had net CO(2) assimilation at leaf temperatures of -0.85 to -1.2 degrees C. In 1989, all species except Cladonia furcata showed net CO(2) assimilation at tissue temperatures of 0 to +3.3 degrees C, with the highest rates observed in Poa bulbosa and F. vaginata. The latter showed a net CO(2) assimilation saturation at a PPFD of 600 micromol m(-2)s(-1) and a temperature optimum between +5 and +18 degrees C. At the 1994 measurements, the photosynthetic rates were higher at higher tissue water contents. The two mosses and lichens had a net photosynthesis (range: 1.1-2.79 micromol CO(2)kg(-1)s(-1)) at 2 degrees C tissue temperature and at 4-5 degrees C air temperature. Ca. 80% of the vascular grassland plant species maintained a positive C-balance during the coldest periods of winter, with photosynthetic rates of 1.5-3.8 micromol CO(2)m(-2)s(-1). In an extremely warm beginning March of the relatively warm winter of 2006/2007, the dicotyledonous plants had much higher CO(2) assimilation rates on a Chl (range 6-14.9 micromol g(-1)Chl s(-1)) and on a dry weight basis (9-48 micromol kg(-1)dw s(-1)) than in the cold winter of 1994. However, the assimilation rates of the three investigated cryptogams (Tortula and two Cladonia) and the two grasses Festuca and Poa were not affected by this increase. The results indicate that the photosynthetic activity of temperate semi-desert sand grassland species can help somewhat in slowing the general CO(2) rise in winter and function as a potential carbon sink of the investigated semi-desert Hungarian grassland species. PMID:18346813

  10. Effects of mild wintering conditions on body mass and corticosterone levels in a temperate reptile, the aspic viper (Vipera aspis).

    Brischoux, François; Dupoué, Andréaz; Lourdais, Olivier; Angelier, Frédéric

    2016-02-01

    Temperate ectotherms are expected to benefit from climate change (e.g., increased activity time), but the impacts of climate warming during the winter have mostly been overlooked. Milder winters are expected to decrease body condition upon emergence, and thus to affect crucial life-history traits, such as survival and reproduction. Mild winter temperature could also trigger a state of chronic physiological stress due to inadequate thermal conditions that preclude both dormancy and activity. We tested these hypotheses on a typical temperate ectothermic vertebrate, the aspic viper (Vipera aspis). We simulated different wintering conditions for three groups of aspic vipers (cold: ~6°C, mild: ~14°C and no wintering: ~24°C) during a one month long period. We found that mild wintering conditions induced a marked decrease in body condition, and provoked an alteration of some hormonal mechanisms involved in emergence. Such effects are likely to bear ultimate consequences on reproduction, and thus population persistence. We emphasize that future studies should incorporate the critical, albeit neglected, winter season when assessing the potential impacts of global changes on ectotherms. PMID:26626954

  11. Dams release methane even in temperate zoned; Les barrages emettent aussi du methane en zones temperees

    Lemarchand, F.

    2010-12-15

    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/m{sup 2}*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.)

  12. Effects of silvicultultural modifications of temperate rainforest on breeding and wintering bird communities, Prince of Wales Island, southeast Alaska

    Dellasala, Dominick A.; Hagar, Joan C.; Engel, Kathleen A.; McComb, W.C.; Fairbanks, Randal L.; Campbell, Ellen G.

    1996-01-01

    We inventoried breeding and wintering bird communities in four treatments of temperate rainforest on Prince of Wales Island, southeast Alaska during 1991-1992 and 1992-1993. The four forest treatments sampled included: (1) young growth (20 years) originating from clearcut logging with no silvicultural modification (non-modified), (2) young growth (20 years) precommercially thinned along uniformly-spaced thinning grids (thinned), (3) young growth (20 years) with gaps in the overstory canopy created by felling trees in 0.05-ha openings (gapped), and (4) virgin old growth (2 150 years). Of 16 common breeding bird species observed, six showed significant responses to young-growth modifications. One species was more abundant and two species were less abundant in thinned sites, while one species was more abundant and two species were less abundant in gapped sites than at least one of the other treatments. None of the three common wintering species of birds observed was influenced by young-growth modification. Breeding bird communities, in general, were less similar between young- and old-growth treatments than among young-growth treatments. Three of the 16 common breeding bird species were more abundant in old growth than each of the young-growth treatments and one uncommon species was detected almost exclusivelyi n old growth duringb oth the breedinga nd wintering seasonsF. our other breeding bird species were more abundant in young-growth treatments than in old growth. Higher use of old growth by wintering birds was related to winter severity. To enhance habitat for wintering and breeding birds we recommend: (1) thinning young growth along variablespaced grids to create additional canopy layers and improve snow-intercept properties of young growth for canopy-foraging birds, (2) retention of old-growth clumps in clearcuts for bird species associated with old-growth structure, and (3) long-term conservation of oldgrowth temperate rainforest for breeding and wintering birds positively associated with old growth.

  13. Pulsed resources at tundra breeding sites affect winter irruptions at temperate latitudes of a top predator, the snowy owl.

    Robillard, A; Therrien, J F; Gauthier, G; Clark, K M; Bêty, J

    2016-06-01

    Irruptive migration is mostly observed in species specialized on pulsed resources and is thought to be a response to unpredictable changes in food supply. We assessed two alternative hypotheses to explain the periodic winter irruptions of snowy owls Bubo scandiacus every 3-5 years in temperate North America: (a) the lack-of-food hypothesis, which states that a crash in small mammal abundance on the Arctic breeding grounds forces owls to move out of the tundra massively to search for food in winter; (b) the breeding-success hypothesis, which states that high abundance of tundra small mammals during the summer allows for high production of young, thus increasing the pool of migrants moving south the following winter. We modeled winter irruptions of snowy owls in relation to summer food resources and geographic location. Winter abundance of owls was obtained from citizen-based surveys from 1994 to 2011 and summer abundance of small mammals was collected in summer at two distant sites in Canada: Bylot Island, NU (eastern High Arctic) and Daring Lake, NWT (central Low Arctic). Winter owl abundance was positively related to prey abundance during the previous summer at both sites and tended to decrease from western to eastern temperate North America. Irruptive migration of snowy owls was therefore best explained by the breeding success hypothesis and was apparently caused by large-scale summer variations in food. Our results, combined with previous findings, suggest that the main determinants of irruptive migration may be species specific even in a guild of apparently similar species. PMID:26920901

  14. Role of temperate zone forests in the world carbon cycle: problem definition and research needs

    Armentano, T.V.; Hett, J. (eds.)

    1979-01-01

    The proceedings of a workshop on carbon uptake and losses from temperate zone forests are presented. The goals of the workshop were to analyze existing data on growth and utilization of the temperate zone forest carbon pool and to identify further research needs in relation to the role of temperate forests in the global carbon cycle. Total standing stock and growth recovery transients were examined for most of the temperate region over a period from pre-settlement times to the present, with emphasis on the last three decades. Because of data availability, certain regions and topics were covered more in detail than others. Forest inventory data from most of the commercial timberlands of the north temperate zone suggest these forests have functioned over the past several decades as an annual sink for about 10/sup 9/ metric tons of carbon. Thus, net growth of these forests has withdrawn carbon from the atmosphere at a rate equivalent, approximately, to 50% of the annual rise in atmospheric carbon. Various data inadequacies make this estimate probably no more precise than plus or minus half of the value. Analysis of growth and vegetation changes in New England and the southeastern United States shows that forest biomass has partly recovered since extensive clearing took place in the 18th and 19th centuries. This regrowth represents a net withdrawal of carbon (carbon sink) from the atmosphere in recent decades, although the difference in pool size between present and original forests means that, in the longer term, the two regions have functioned as carbon sources.

  15. Physiological and behavioural correlates of life-history variation: a comparison between tropical and temperate zone House Wrens

    Tieleman, BI; Lasky, [No Value; Mauck, RA; Visser, GH; Williams, JB; Lasky, J.R.; Kozłowski, Jan

    2006-01-01

    1. We studied physiological, behavioural and demographic traits of House Wrens (Troglodytes aedon) in tropical Panama and temperate zone Ohio to explore the hypothesis that tropical birds with higher adult survival rates invest less in annual reproduction than their temperate zone counterparts. 2. Compared with wrens from Ohio, Panamanian wrens invested fewer resources in a given reproductive episode, as quantified by lower parental field metabolic rate (FMR) and water influx rate (WIR), a sm...

  16. Using weather indices to predict survival of winter wheat in a cool temperate environment

    Hayhoe, H. N.; Lapen, D. R.; Andrews, C. J.

    2002-10-01

    Seven years of winter survival data for winter wheat (Triticum aestivum L.) were collected on a loam soil located on the Central Experimental Farm at Ottawa, Ontario (45°23'N, 75°43'W). The site was low-lying and subject to frequent winter flooding and ice-sheet formation. Two cultivars, a soft white and a hard red winter wheat, were planted in September. Crop establishment was measured in late fall and the percentage survival was measured in April of the following year. Meteorological data, which were available from the nearby weather site, were used to develop a large set of monthly weather indices that were felt to be important for winter survival. The objective of the study was to use genetic selection algorithms and artificial neural networks to select a subset of critical weather factors and topographic features and to model winter survival. The six weather indices selected were the total rain depth for December (mm), the total rain depth for February (mm), the number of days of the month with snow on the ground for January, the extreme minimum observed daily air temperature for March (°C), the number of days of the month with snow on the ground for March, and the number of days of April with a daily maximum air temperature greater than 0 °C. It was found 89% of the variation in winter survival could be explained by these six weather indices, the cultivar, elevation and plot location.

  17. Urban spring phenology in the middle temperate zone of China: dynamics and influence factors.

    Liang, Shouzhen; Shi, Ping; Li, Hongzhong

    2016-04-01

    Urbanization and its resultant urban heat island provide a means for evaluating the impact of climate warming on vegetation phenology. To predict the possible response of vegetation phenology to rise of temperature, it is necessary to investigate factors influencing vegetation phenology in different climate zones. The start of growing season (SOS) in seven cities located in the middle temperate humid, semi-humid, semi-arid, and arid climate zones in China was extracted based on satellite-derived normalized difference vegetation index (NDVI) data. The dynamics of urban SOS from 2000 to 2009 and the correlations between urban SOS and land surface temperatures (LST), precipitation, and sunshine duration, respectively, were analyzed. The results showed that there were no obvious change trends for urban SOS, and the heat island induced by urbanization can make SOS earlier in urban areas than that in adjacent rural areas. And the impact of altitude on SOS was also not negligible in regions with obvious altitude difference between urban and adjacent rural areas. Precipitation and temperature were two main natural factors influencing urban SOS in the middle temperate zone, but their impacts varied with climate zones. Only in Harbin city with lower sunshine duration in spring, sunshine duration had more significant impact than temperature and precipitation. Interference of human activities on urban vegetation was non-negligible, which can lower the dependence of urban SOS on natural climatic factors. PMID:26272052

  18. Urban spring phenology in the middle temperate zone of China: dynamics and influence factors

    Liang, Shouzhen; Shi, Ping; Li, Hongzhong

    2015-08-01

    Urbanization and its resultant urban heat island provide a means for evaluating the impact of climate warming on vegetation phenology. To predict the possible response of vegetation phenology to rise of temperature, it is necessary to investigate factors influencing vegetation phenology in different climate zones. The start of growing season (SOS) in seven cities located in the middle temperate humid, semi-humid, semi-arid, and arid climate zones in China was extracted based on satellite-derived normalized difference vegetation index (NDVI) data. The dynamics of urban SOS from 2000 to 2009 and the correlations between urban SOS and land surface temperatures (LST), precipitation, and sunshine duration, respectively, were analyzed. The results showed that there were no obvious change trends for urban SOS, and the heat island induced by urbanization can make SOS earlier in urban areas than that in adjacent rural areas. And the impact of altitude on SOS was also not negligible in regions with obvious altitude difference between urban and adjacent rural areas. Precipitation and temperature were two main natural factors influencing urban SOS in the middle temperate zone, but their impacts varied with climate zones. Only in Harbin city with lower sunshine duration in spring, sunshine duration had more significant impact than temperature and precipitation. Interference of human activities on urban vegetation was non-negligible, which can lower the dependence of urban SOS on natural climatic factors.

  19. Urban spring phenology in the middle temperate zone of China: dynamics and influence factors

    Liang, Shouzhen; Shi, Ping; Li, Hongzhong

    2016-04-01

    Urbanization and its resultant urban heat island provide a means for evaluating the impact of climate warming on vegetation phenology. To predict the possible response of vegetation phenology to rise of temperature, it is necessary to investigate factors influencing vegetation phenology in different climate zones. The start of growing season (SOS) in seven cities located in the middle temperate humid, semi-humid, semi-arid, and arid climate zones in China was extracted based on satellite-derived normalized difference vegetation index (NDVI) data. The dynamics of urban SOS from 2000 to 2009 and the correlations between urban SOS and land surface temperatures (LST), precipitation, and sunshine duration, respectively, were analyzed. The results showed that there were no obvious change trends for urban SOS, and the heat island induced by urbanization can make SOS earlier in urban areas than that in adjacent rural areas. And the impact of altitude on SOS was also not negligible in regions with obvious altitude difference between urban and adjacent rural areas. Precipitation and temperature were two main natural factors influencing urban SOS in the middle temperate zone, but their impacts varied with climate zones. Only in Harbin city with lower sunshine duration in spring, sunshine duration had more significant impact than temperature and precipitation. Interference of human activities on urban vegetation was non-negligible, which can lower the dependence of urban SOS on natural climatic factors.

  20. The effect of introducing a winter forage rotation on CO2 fluxes at a temperate grassland

    Leahy, Paul G.; Kiely, Gerard

    2012-01-01

    Temperate grasslands have the potential to sequester carbon, helping to mitigate rising atmospheric CO2 concentrations. The ability of grasslands to absorb CO2 is influenced by site elevation, soil type, management practices, climate and climatic variability. There is a need for long-term observations and field experiments to quantify the effects of the key drivers of management and climate variability. This paper presents over 4 years of eddy covariance measurements of CO2 flux over a manage...

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

    J. C. Stager

    2012-05-01

    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.

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

    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

    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.

  3. Conference on the Rehabilitation of Severely Damaged Land and Freshwater Ecosystems in Temperate Zones

    Woodman, M

    1978-01-01

    This volume contains the papers presented at a conference on "The rehabilitation of severely damaged land and freshwater eco­ systems in temperate zones", held at Reykjavik, Iceland, from 4th to 11th July, 1976. The meeting was held under the auspices of the Ecosciences Panel of the N.A.T.O. Science Committee, and the organising expenses and greater part of the expenses of the speakers and chairmen were provided by N.A.T.O. The scientific programme was planned by M. W. Holdgate and M. J. Woodman, in consultation with numerous colleagues, and especially with the Administrative Director of the Conference in Iceland, Dr. Sturla Fridriksson. Iceland proved a particularly suitable location for such a Conference. Geologically, it is one of the youngest countries 1n the world, owing its origin to the up-welling of volcanic rock along the spreading zone of the mid-Atlantic ridge within the past 20 million years. Its structure, northern oceanic situation, recent glaciation and continuing volcanic activity make it dis...

  4. Tropical Agroecosystems: These habitats are misunderstood by the temperate zones, mismanaged by the tropics.

    Janzen, D H

    1973-12-21

    I have listed some of the ways in which the lowland tropics are not such a warm and wonderful place for the farmer, some of the reasons why it may be unreasonable to expect him to cope with the problems, and some of the ways in which the temperate zones make his task more difficult. The tropics are very close to being a tragedy of the commons on a global scale (69, 103), and it is the temperate zone's shepherds and sheep who are among the greatest offenders (31). Given that the temperate zones have some limited amount of resources with which they are willing to repay the tropics, how can these resources best be spent? The first answer, without doubt, is education, and the incorporation of what is already known about the tropics into that education. Second should be the generation of secure psychological and physical resources for governments that show they are enthusiastic about the development of an SYTA. Third should be support of intensive research needed to generate the set of site-specific rules for specific, clearly identified SYTA's. The subject matter of youths' cultural programming is presumably determined by what they will need during the rest of their lives. A major component of this programming should be the teaching of the socioeconomic rules of a sustained-yield, nonexpanding economy, tuned to the concept of living within the carrying capacity of the country's or region's resources. Incorporating such a process into tropical school systems will cause a major upheaval, if for no other reason than that it will involve an evaluation of the country's resources, what standard of living is to be accepted by those living on them, and who is presently harvesting them. Of even greater impact, it will have to evaluate resources in terms of their ability to raise the standard of living by Y amount for X proportion of the people in the region, rather than in terms of their cash value on the world market. For such a change to be technologically successful, it will require a great deal of pantropical information exchange. This information exchange will cost a great deal of resource, not only in travel funds and support of on-site study, but in insurance policies for the countries that are willing to take the risk of trying to change from an exploitative agroecosystem to an SYTA. For such an experiment to be sociologically successful, it will require a complete change in tropical educational systems, from emphasizing descriptions of events as they now stand, to emphasizing analysis of why things happen the way they do. This will also be very expensive, not only in retreading the technology and mind-sets of current teaching programs, but in gathering the facts on why the tropics have met their current fate. There is a surfeit of biological and agricultural reports dealing with ecological experiments and generalities which suggest that such and such will be the outcome if such and such form of resource harvest is attempted. It is clear that human desiderata regarding a particular site are often radically different from the needs of the "average" wild animals and plants that formed the basis for such experiments and generalities. A finely tuned SYTA will come close to providing a unique solution for each region. The generalities that will rule it are highly stochastic. The more tropical the region, the more evenly weighted the suboutcomes will be, and thus the more likely each region will be to have a unique overall outcome. For example, it is easy to imagine four different parts of the tropics, each with the same kind of soil and the same climate, with four different, successful SYTA's, one based on paddy rice, one on shelterwood forestry, one on tourism, and one on shifting maize culture. A regional experiment station working holistically toward an SYTA is potentially one of the best solutions available. As currently structured, however, almost all tropical experiment stations are inadequate for such a mission. Most commonly they are structured around a single export crop such as coffee, sugar, rubber, cotton, cacao, or tea. A major portion of their budgets comes directly or indirectly from the industry concerned. This industry can hardly be expected to wish to see its production integrated with a sustained-yield system that charges real costs for its materials. When an experiment station is centered around a major food crop, such as rice or maize, the goal becomes one of maximizing production per acre rather than per unit of resource spent; this goal may often be translated into one of generating more people. More general experiment stations tend to be established in the most productive regions of the country and, therefore, receive the most funding. Such regions (islands, intermediate elevations, areas with severe dry seasons) need experiment stations the least because they can often be successfully farmed with only slightly modified temperate zone technologies and philosophies. The administrators of tropical experiment stations often regard their job as a hardship post and tend to orient their research toward the hand that feeds them, which is certainly not the farming communities in which they have been placed. The tropics do not need more hard cash for tractors; they need a program that will show when, where, and how hand care should be replaced with draft animals, and draft animals with tractors. The tropics do not need more randomly gathered, esoteric or applied agricultural research: they need a means to integrate what is already known into the process of developing SYTA's. The tropics do not need more food as much as a means of evaluating the resources they have and generating social systems that will maximize the standard of living possible with those resources, whatever the size. The tropics need a realistic set of expectations. PMID:17811308

  5. Performance of a temperate-zone channel catfish biofloc technology production system during winter

    Channel catfish (Ictalurus punctatus) have been grown successfully in an outdoor biofloc technology production system. Outdoor biofloc production systems in the tropics are operated year-round, whereas the channel catfish studies were conducted only during the growing season and biofloc production t...

  6. The northern limit of corals of the genus Acropora in temperate zones is determined by their resilience to cold bleaching.

    Higuchi, Tomihiko; Agostini, Sylvain; Casareto, Beatriz Estela; Suzuki, Yoshimi; Yuyama, Ikuko

    2015-01-01

    The distribution of corals in Japan covers a wide range of latitudes, encompassing tropical to temperate zones. However, coral communities in temperate zones contain only a small subset of species. Among the parameters that determine the distribution of corals, temperature plays an important role. We tested the resilience to cold stress of three coral species belonging to the genus Acropora in incubation experiments. Acropora pruinosa, which is the northernmost of the three species, bleached at 13 °C, but recovered once temperatures were increased. The two other species, A. hyacinthus and A. solitaryensis, which has a more southerly range than A. pruinosa, died rapidly after bleaching at 13 °C. The physiological effects of cold bleaching on the corals included decreased rates of photosynthesis, respiration, and calcification, similar to the physiological effects observed with bleaching due to high temperature stress. Contrasting hot bleaching, no increases in antioxidant enzyme activities were observed, suggesting that reactive oxygen species play a less important role in bleaching under cold stress. These results confirmed the importance of resilience to cold stress in determining the distribution and northern limits of coral species, as cold events causing coral bleaching and high mortality occur regularly in temperate zones. PMID:26680690

  7. Studies on partially melted zone in aluminium-copper alloy welds-effect of techniques and prior thermal temper

    Partially melted zone (PMZ) of aluminium alloy welds is an important region and requires careful attention. This is mainly because PMZ in these materials is weak link in the weldments and is significantly affected by welding parameters. Microstructure changes in PMZ are related not only to welding heat input and techniques, but also depend on the initial thermal history of alloy (for example, whether it is in T6 or T87 condition etc.). Interestingly, not many detailed studies were available in this respect. In the present work, effect of prior thermal temper and welding techniques mainly continuous and pulsed current gas tungsten arc welding (GTAW) on the PMZ behaviour of AA2219 alloy was studied. Susceptibility to liquation was found to be high in T6 temper of AA2219 alloy than in T87. Pulsed current technique was found to improve the resistance to the susceptibility to liquation in PMZ

  8. Exposure and respiratory health in farming in temperate zones--a review of the literature.

    Omland, Øyvind

    2002-01-01

    To review studies in farming populations from temperate zones focusing on: (1) exposure to dust, bacteria, moulds, endotoxin, and ammonia, (2) sensitisation to common airborne allergens, (3) prevalence, incidence and risk factors of chronic bronchitis, asthma and bronchial hyperresponsiveness, and (4) measurements of lung function. Working in animal housings can be associated with exposure to organic dust, bacteria, moulds, endotoxin, and ammonia in concentrations that can induce cellular and immunological responses and result in respiratory diseases. Working in poultry housing might be associated with higher exposures to dust, bacteria, and ammonia than in swine and cow housings, and endotoxin exposure seems to be higher in North America than in Europe. Working exposure might influence the domestic area on farms, and there might be a protective effect of being raised on a farm regarding sensitisation and allergic diseases. Sensitisation to mites seems to be the most prevalent of the common inhalant allergens. Chronic bronchitis is frequent and data suggests that it is work related in farmers. Findings concerning asthma are less uniform, and data regarding bronchial hyperresponsiveness are too sparse and inconsistent to evaluate the effect on farming. Several risk factors have been described, and age is shared for all three clinical manifestations, while male gender, atopy, smoking, pig farming, and animal production are common risk factors for chronic bronchitis and asthma. FEV(1), and FEV(1)/FVC seems to be reduced in farmers, and longitudinal studies indicate an increased annual loss in FEV(1) in farmers, especially in pig farmers. The increased annual decline has been associated with lung function, bronchial hyperresponsiveness, smoking, automatic dry feeding systems, and endotoxin. Despite studies with methodological weaknesses, heterogenity in sampling times, measurement techniques, equipment, and diagnostic criteria, the review has revealed that the exposure to organic dust in farming can be substantial and might lead to respiratory diseases and increased annual loss in lung function. Working exposure seems to influence the domestic area in farms, and being raised on a farm might have a protective effect regarding sensitisation and allergic diseases. PMID:12498578

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

    van Vuuren, A M; Chilibroste, P

    2013-03-01

    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

  10. Radiocarbon and stable carbon isotope compositions of chemically fractionated soil organic matter in a temperate-zone forest

    To better understand the role of soil organic matter in terrestrial carbon cycle, carbon isotope compositions in soil samples from a temperate-zone forest were measured for bulk, acid-insoluble and base-insoluble organic matter fractions separated by a chemical fractionation method. The measurements also made it possible to estimate indirectly radiocarbon (14C) abundances of acid- and base-soluble organic matter fractions, through a mass balance of carbon among the fractions. The depth profiles of 14C abundances showed that (1) bomb-derived 14C has penetrated the first 16 cm mineral soil at least; (2) Δ14C values of acid-soluble organic matter fraction are considerably higher than those of other fractions; and (3) a significant amount of the bomb-derived 14C has been preserved as the base-soluble organic matter around litter-mineral soil boundary. In contrast, no or little bomb-derived 14C was observed for the base-insoluble fraction in all sampling depths, indicating that this recalcitrant fraction, accounting for approximately 15% of total carbon in this temperate-zone forest soil, plays a role as a long-term sink in the carbon cycle. These results suggest that bulk soil organic matter cannot provide a representative indicator as a source or a sink of carbon in soil, particularly on annual to decadal timescales

  11. Root and soil carbon distribution at shoulderslope and footslope positions of temperate toposequences cropped to winter wheat

    Chirinda, Ngoni; Roncossek, Svenja Doreen; Heckrath, Goswin Johann; Elsgaard, Lars; Thomsen, Ingrid Kaag; Olesen, Jrgen E

    2014-01-01

    Crop root residues are an important source of soil organic carbon (SOC) in arable systems. However, the spatial distribution of root biomass in arable systems remains largely unknown. In this study, we determined the spatial distribution of macro-root and shoot biomass of winter wheat at shoulder......Crop root residues are an important source of soil organic carbon (SOC) in arable systems. However, the spatial distribution of root biomass in arable systems remains largely unknown. In this study, we determined the spatial distribution of macro-root and shoot biomass of winter wheat at...

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

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

    2012-01-01

    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...

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

    He, M. Z.

    2012-04-01

    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 establishment of PVC collars, each plot falling within distances less than 2.0 m of an existing replicate was discarded and reallocated to ensure a minimum distance between replicates of 2.0 m. Soil respiration was measured with a LI-6400 and a soil CO2 flux chamber (LI-6400-09). The target value was set close to the ambient CO2 concentration (~380μmolmol_1), and the ΔCO2 value was set as the factory default value (10μmolmol-1) (LiCor 1997). Thin-walled PVC collars were inserted at least one night (12h) before measurement so as to avert CO2 flushing, as recommended by LiCor (1997). Measurements were performed monthly between November 2010 (1months after the collars were inserted to avoid any bias promoted by soil alteration during the placement of collars) and March 2010. Diurnal Rs were measured every two hours from 8:00 to 6:00 of the next day. In parallel to the measurements of soil respiration, Measurements of soil respiration, soil moisture, and soil temperature were taken according to a stratified random design. Important findings (1) The RS was positively correlated to soil temperature in all BSCs, and was significantly influenced by the interactions of soil temperature and water content in moss, lichen and mixed BSCs. (2) The sensitivity of RS to soil temperature at 10cm depth (Q10) ranged from 1.25 in moss-dominated BSCs to 1.63 lichen-dominated BSCs. The Q10 tended to increase with soil temperature until reaching a threshold, and then decline. (3) Soil respiration rates remained low at night time and exhibited as single-peak curve at day time from April to October, and compare to the shifting sand area, a remarkable monthly variation occured in the BSCs dominated area. (4) The winter RS for the moss, lichen, and mixed BSCs averaged 102, 56 and 85 gCm-2 winter time_1, respectively. The winter RS was positively correlated to soil organic carbon (SOC) concentration at O horizon. Our results indicate that winter Rs of BSCs-dominated areas are the main contributor to the total carbon released by soil respiration and, therefore, which we should considered when estimating carbon budgets in desert ecosystems. Key words: Winter Soil Respiration; Biological Soil Crust (BSCs); Q10

  14. Silvicultural management in maintaining biodiversity and resistance of forests in Europe-temperate zone.

    Spiecker, Heinrich

    2003-01-01

    In Europe temperate forests play a prominent role in timber production, nature protection, water conservation, erosion control and recreation. For centuries temperate forests in Europe have been affected by forest devastation and soil degradation. Applying great efforts to eliminate the severe wood shortage of those days, countermeasures were taken during the last 150 years by regenerating and tending highly productive forests. High growth rates and an increasing growing stock of these forests indicate that formerly stated goals have been successfully achieved. Coniferous species were often favoured because they were easy to establish and manage, and gave reason for high volume growth expectations. Today coniferous forests expand far beyond the limits of their natural ranges. These changes have been accompanied by a loss of biodiversity, a shift to nonsite adapted tree species and reduce the resistance against storms, snow, ice, droughts, insects and fungi. Some of these hazards were further intensified by the increasing average stand age, as well as in some areas by severe air pollution. Climatic fluctuations, especially changes in the frequency and intensity of extreme warm and dry climatic conditions and of heavy storms, had considerable impact on forest ecosystems. The changing demands of today require a widened scope of forest management. Society is asking for sustainable forestry emphasizing biodiversity and naturalistic forest management. It is of great economic and ecological relevance to know on which sites today's forests are most susceptible to climatic and other environmental changes and hazards. In those areas adjustments of management through a conversion the prevailing forests towards more site adapted mixed forests needs to be considered with priority. The high diversity in site conditions, ownership, economic and socio-cultural conditions require strategies adapted to the local and regional needs. Higher resistance of forests will increase economic and social benefits of forests and reduce the risks by maintaining sustainable forestry. PMID:12659804

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

    Szczucinski, W.

    2013-12-01

    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.

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

    Winde, V.; Bttcher, M. E.; Escher, P.; Bning, P.; Beck, M.; Liebezeit, G.; Schneider, B.

    2014-01-01

    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.

  17. Hydraulic conductivity, photosynthesis and leaf water balance in six evergreen woody species from fall to winter.

    Taneda, Haruhiko; Tateno, Masaki

    2005-03-01

    To confirm that freeze-thaw embolism is a primary stress for evergreen woody species in winter, hydraulic conductivity, photosynthesis and leaf water potential were measured during fall and winter in trees growing in a cool temperate zone (Nikko) and in a warm temperate zone (Tokyo). We examined two evergreen conifers that naturally occur in the cool temperate zone (Abies firma Siebold & Zucc. and Abies homolepis Siebold & Zucc.), and four evergreen broad-leaved woody species that are restricted to the warm temperate zone (Camellia japonica L., Cinnamomum camphora (L.) J. Presl, Ilex crenata Thunb. and Quercus myrsinaefolia Blume). In Tokyo, where no freeze-thaw cycles of xylem sap occurred, hydraulic conductivity, photosynthesis and water balance remained constant during the experimental period. In Nikko, where there were 38 daily freeze-thaw cycles by February, neither of the tracheid-bearing evergreen conifers showed xylem embolism or leaf water deficits. Similarly, the broad-leaved evergreen trees with small-diameter vessels did not exhibit severe embolism or water deficits and maintained CO(2) assimilation even in January. In contrast, the two broad-leaved evergreen trees with large-diameter vessels showed significantly reduced hydraulic conductivity and shoot die-back in winter. We conclude that freeze-thaw embolism restricts evergreen woody species with large-diameter vessels to the warm temperate zone, whereas other stresses limit the distribution of broad-leaved trees, that have small-diameter vessels, but which are restricted to the warm temperate zone. PMID:15631978

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

    Poeplau, Christopher; Don, Axel; Vesterdal, Lars; Leifeld, Jens; van Wesemaels, Bas; Schumacher, Jens; Gensior, Andreas

    2011-01-01

    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...

  19. Habitat use by larval fishes in a temperate South African surf zone

    Watt-Pringle, Peter; Strydom, Nadine A.

    2003-12-01

    Larval fishes were sampled in the Kwaaihoek surf zone on the south east coast of South Africa. On six occasions between February and May 2002, larval fishes were collected in two habitat types identified in the inner surf zone using a modified beach-seine net. The surf zone habitats were classified as either sheltered trough areas or adjacent exposed surf areas. Temperature, depth and current measurements were taken at all sites. Trough habitats consisted of a depression in surf topography characterised by reduced current velocities and greater average depth than adjacent surf areas. In total, 325 larval fishes were collected. Of these, 229 were collected in trough and 96 in surf habitats. At least 22 families and 37 species were represented in the catch. Dominant families were the Mugilidae, Sparidae, Atherinidae, and Engraulidae. Dominant species included Liza tricuspidens and Liza richardsonii (Mugilidae), Rhabdosargus holubi and Sarpa salpa (Sparidae), Atherina breviceps (Atherinidae) and Engraulis japonicus (Engraulide). Mean CPUE of postflexion larvae of estuary-dependent species was significantly greater in trough areas. The proportion of postflexion larval fishes in trough habitat was significantly greater than that of preflexion stages, a result that was not apparent in surf habitat sampled. CPUE of postflexion larvae of estuary-dependent fishes was negatively correlated with current magnitude and positively correlated with habitat depth. Mean body length of larval fishes was significantly greater in trough than in surf habitats. These results provide evidence that the CPUE of postflexion larvae of estuary-dependent fishes is higher in trough habitat in the surf zone and this may be indicative of active habitat selection for areas of reduced current velocity/wave action. The implications of this behaviour for estuarine recruitment processes are discussed.

  20. 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.

    Daz Ravia, M.; Bueno, J.; Gonzlez Prieto, S. J.; Carballas, T.

    2005-01-01

    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...

  1. Holocene climate variability in the winter rainfall zone of South Africa

    S. Weldeab

    2012-06-01

    Full Text Available We established a multi-proxy time series comprising analyses of major elements in bulk sediments, Sr and Nd isotopes, grain size of terrigenous fraction, and δ18O and δ13C 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 evidence of a poleward shift of the austral mid-latitude westerlies 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 variation of dust incursion over Antarctica suggests a causal link that most likely was related to latitudinal shifts of the Southern Hemisphere westerlies and changes in the amount of Agulhas water leakage into the Southern BUS. 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.

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

    Poeplau, Christopher; Don, Axel; Vesterdal, Lars; Leifeld, Jens; van Wesemaels, Bas; Schumacher, Jens; Gensior, Andreas

    2011-01-01

    sink of 11654%, 100 years after LUC (mean95% 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...... 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 306 cm). Grassland establishment caused a long lasting carbon sink with a relative stock change of 12823% and afforestation on former cropland a......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...

  3. Relation of Chlorophyll Fluorescence Sensitive Reflectance Ratios to Carbon FluxMeasurements ofMontanne Grassland and Norway Spruce Forest Ecosystems in the Temperate Zone

    Ač, Alexander; Malenovský, Z.; Urban, Otmar; Hanuš, Jan; Zitová, Martina; Navrátil, M.; Vráblová, M.; Olejníčková, Julie; Špunda, V.; Marek, Michal V.

    2012-01-01

    Roč. 2012, č. 2012 (2012), s. 1-13. ISSN 1537-744X R&D Projects: GA MŽP(CZ) SP/2D1/70/08; GA MŽP(CZ) SP/2D1/93/07; GA MŠk(CZ) LM2010007; GA MŠk(CZ) ED1.1.00/02.0073 Institutional research plan: CEZ:AV0Z60870520 Keywords : Chlorophyll fluorescence * carbon flux * forest ecosystems * Norway Spruce * temperate zone Subject RIV: EH - Ecology, Behaviour Impact factor: 1.730, year: 2012

  4. 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

    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)

  5. Selection on a eumelanic ornament is stronger in the tropics than in temperate zones in the worldwide-distributed barn owl.

    Roulin, A; Wink, M; Salamin, N

    2009-02-01

    Spatial variation in the pattern of natural selection can promote local adaptation and genetic differentiation between populations. Because heritable melanin-based ornaments can signal resistance to environmentally mediated elevation in glucocorticoids, to oxidative stress and parasites, populations may vary in the mean degree of melanic coloration if selection on these phenotypic aspects varies geographically. Within a population of Swiss barn owls (Tyto alba), the size of eumelanic spots is positively associated with survival, immunity and resistance to stress, but it is yet unknown whether Tyto species that face stressful environments evolved towards a darker eumelanic plumage. Because selection regimes vary along environmental gradients, we examined whether melanin-based traits vary clinally and are expressed to a larger extent in the tropics where parasites are more abundant than in temperate zones. To this end, we considered 39 barn owl species distributed worldwide. Barn owl species living in the tropics displayed larger eumelanic spots than those found in temperate zones. This was, however, verified in the northern hemisphere only. Parasites being particularly abundant in the tropics, they may promote the evolution of darker eumelanic ornaments. PMID:19032496

  6. GROWTH, DEVELOPMENT AND YIELD OF WINTER BARLEY IN THE CENTRAL ZONE OF THE KRASNODAR REGION

    Sysenko I. S.

    2016-01-01

    Full Text Available The article deals with a combination of different methods of cultivation of winter barley on the background of plowing, and their impact on growth, development and crop yield. The main technological factors allowing implementing the biological potential of culture are adaptive variety, quality seeds, predecessors, sowing and harvesting, fertilizer, soil fertility, crop care, including protection from weeds, pests and diseases. Barley is the culture of versatile use, which is grown for food and feed purposes. Intensification of cultivation methods of this phenomenon is essential and significantly affects the grain yield of this crop. Under the natural fertility of the soil and favorable weather conditions for black earth of Kuban it is possible to get 3,0-3,5 tons per hectare of winter crops of grain, and this requires the creation of an optimal diet, because one of the main factors affecting the productivity of field crops, including one phenomenon are fertilizers. In addition, the level of soil fertility and protection system of weeds, pests and diseases has great importance. Since these types of issues are relevant for agriculture, we have carried out studies to identify the optimal combination of different methods on growth, development and productivity of a single phenomenon

  7. Diversification rates and chromosome evolution in the most diverse angiosperm genus of the temperate zone (Carex, Cyperaceae).

    Escudero, Marcial; Hipp, Andrew L; Waterway, Marcia J; Valente, Luis M

    2012-06-01

    The sedge family (Cyperaceae: Poales; ca. 5600 spp.) is a hyperdiverse cosmopolitan group with centres of species diversity in Africa, Australia, eastern Asia, North America, and the Neotropics. Carex, with ca. 40% of the species in the family, is one of the most species-rich angiosperm genera and the most diverse in temperate regions of the Northern Hemisphere, making it atypical among plants in that it inverts the latitudinal gradient of species richness. Moreover, Carex exhibits high rates of chromosome rearrangement via fission, fusion, and translocation, which distinguishes it from the rest of the Cyperaceae. Here, we use a phylogenetic framework to examine how the onset of contemporary temperate climates and the processes of chromosome evolution have influenced the diversification dynamics of Carex. We provide estimates of diversification rates and map chromosome transitions across the evolutionary history of the main four clades of Carex. We demonstrate that Carex underwent a shift in diversification rates sometime between the Late Eocene and the Oligocene, during a global cooling period, which fits with a transition in diploid chromosome number. We suggest that adaptive radiation to novel temperate climates, aided by a shift in the mode of chromosome evolution, may explain the large-scale radiation of Carex and its latitudinal pattern of species richness. PMID:22366369

  8. Annual soil CO2 efflux in a cold temperate forest in northeastern China: effects of winter snowpack and artificial nitrogen deposition

    Liu, Boqi; Mou, Changcheng; Yan, Guoyong; Xu, Lijian; Jiang, Siling; Xing, Yajuan; Han, Shijie; Yu, Jinghua; Wang, Qinggui

    2016-01-01

    We conducted a snow depth 0?cm (non-snowpack), 10?cm, 20?cm, 30?cm and natural depth) gradient experiment under four quantities of nitrogen addition (control, no added N; low-N, 5?g N m?2 yr?1 medium-N, 10?g N m?2 yr?1 and high-N, 15?g N m?2 yr?1) and took an-entire-year measurements of soil respiration (Rs) in Korean pine forests in northeastern China during 20132014. No evidence for effects of N on Rs could be found during the growing season. On the other hand, reduction of snowpack decreased winter soil respiration due to accompanied relatively lower soil temperature. We found that winter temperature sensitivities (Q10) of Rs were significantly higher than the growing season Q10 under all the N addition treatments. Moderate quantities of N addition (low-N and medium-N) significantly increased temperature sensitivities (Q10) of Rs, but excessive (high-N) addition decreased it during winter. The Gamma empirical model predicted that winter Rs under the four N addition treatments contributed 4.8.??0.3% (control), 3.6??0.6% (low-N), 4.3??0.4% (medium-N) and 6.4??0.5% (high-N) to the whole year Rs. Our results demonstrate that N deposition will alter Q10 of winter Rs. Moreover, winter Rs may contribute very few to annual Rs budget.

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

    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.

  10. Nuclear winter

    Recent studies predict that even a medium-scale nuclear war in the northern hemisphere may cause cooling in the mid-latitudes of the southern hemisphere. The impact of such cooling on agriculture depends on the magnitude, duration and starting date of the southern nuclear winter. Cooling in the middle of the growing season (summer) can have serious consequences, whereas cooling during the dormant season (winter) may have little effect. Various temperature reduction schemes are considered. A cooling of 5 deg. C, equivalent to temperatures during the last glacial maximum, dramatically reduces primary production. A spring cooling of 3 deg. C and other seasons of 1 deg. C eliminates yields from many warm temperate crops and lowers grass production. Smaller temperature decreases have less effect. Given the limitations and uncertainties of the models, these scenarios should be treated with caution; but our results show that a northern hemisphere war could significantly affect New Zealand agriculture

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

    Marta Ziemińska-Smyk

    2013-12-01

    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.

  12. A study of energy performance and audit of commercial mall in hot-summer/warm-winter climate zone in China

    Zhisheng, Li; Jiawen, Liao; Xiaoxia, Wang [School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou, Guangdong, 510006 (China); Lin, Yaolin [Building Energy Solutions and Technologies, Inc, San Jose Office, San Jose, CA 95134 (United States); Xuhong, Liu [School of Architecture and Urban Planning, Guangdong University of Technology, Guangzhou, Guangdong, 510643 (China)

    2013-08-15

    The building energy performance improvement of large-scale public buildings is very important to release China's energy shortage pressure. The aim of the study is to find out the building energy saving potentials of large-scale public and commercial buildings by energy audit. In this paper, the energy consumption, energy performance, and audit were carried out for a typical commercial mall, the so-called largest mall in Asia, located in a hot-summer and warm-winter climate zone. The total annual energy consumption reaches 210.01 kWh/m{sup 2}, of which lighting energy consumption accounts for 30.03 kWh/m{sup 2} and the lift and elevator energy consumption accounts for 40.46 kWh/m{sup 2}. It is by far higher than that of the average building energy consumption in the same category. However, the annual heating, ventilation, and air-conditioning (HVAC) energy consumption is only 87.19 kWh/m{sup 2} even though they run 24/7. It proves that the energy performance of the HVAC system is good. Therefore, the building energy savings potential mainly relies on reducing the excessive usage of lighting, lifts, and elevators.

  13. The impacts of intense moisture transport on the deep and marginal sea-ice zones of the Arctic during winter

    Woods, Cian; Caballero, Rodrigo

    2015-04-01

    Over the past few decades observations have shown that the Arctic is warming at a much faster rate than the global average; a phenomenon know as polar amplification. This tendency for the high latitudes to warm at a disproportionate rate compared to the global average is also a robust feature of global climate model simulations and highlights the importance of climate research in this region. The most often cited mechanism explaining polar amplification is the ice-albedo feed-back; a mechanism by which the surface albedo decreases as sea ice retreats in response to a warming climate. This in turn leads to a higher absorption of insolation and the melting of more ice. In recent years the role of the ice-albedo feedback mechanism as the main cause of polar amplification has been brought into question. GCM studies show a slight reduction of the total poleward energy transport in a warming climate; with the dry static component decreasing at a much faster rate than the moist component. This repartitioning of the poleward energy transport has implications for the formation of clouds in the Arctic, which induce a secondary warming by trapping escaping OLR. These cloud processes in the atmosphere can explain at least part of the recent temperature amplification in the Arctic; and indeed even aquaplanet model studies with zero sea-ice reproduce the polar amplification phenomenon. Directionally, the ice-albedo feedback is a "bottom-up" process; inducing warming in the atmosphere from an increasing surface heat source i.e. more open ocean. The opening of more ocean surface is also consistent with the bottom amplified structure of warming in the Arctic. Here we present evidence for a mechanism in the atmosphere that matches with observations, but in fact acts the opposite direction i.e. "top-down", whereby moist air masses from lower latitudes, termed "moisture intrusions", travelling over the sea-ice increase the longwave down radiation and in turn induce a bottom amplified warming at the surface. There are an average of 14 such events that enter the polar cap each winter, driving about 50% of the seasonal variation in surface temperature over the deep Arctic. We show that, over the last 30 years, the marginal ice-zones in the Barents, Labrador and Chukchi Seas have experienced roughly a doubling in the frequency of these intense moisture intrusion events during winter. Interestingly, these are the regions that have experienced the most rapid wintertime ice loss in the Arctic, raising the question: to what extent has the recent Arctic warming been driven by local vs. interannual/remote processes?

  14. Future climate change is predicted to shift long-term persistence zones in the cold-temperate kelp Laminaria hyperborea.

    Assis, Jorge; Lucas, Ana Vaz; Brbara, Ignacio; Serro, Ester lvares

    2016-02-01

    Global climate change is shifting species distributions worldwide. At rear edges (warmer, low latitude range margins), the consequences of small variations in environmental conditions can be magnified, producing large negative effects on species ranges. A major outcome of shifts in distributions that only recently received attention is the potential to reduce the levels of intra-specific diversity and consequently the global evolutionary and adaptive capacity of species to face novel disturbances. This is particularly important for low dispersal marine species, such as kelps, that generally retain high and unique genetic diversity at rear ranges resulting from long-term persistence, while ranges shifts during climatic glacial/interglacial cycles. Using ecological niche modelling, we (1) infer the major environmental forces shaping the distribution of a cold-temperate kelp, Laminaria hyperborea (Gunnerus) Foslie, and we (2) predict the effect of past climate changes in shaping regions of long-term persistence (i.e., climatic refugia), where this species might hypothetically harbour higher genetic diversity given the absence of bottlenecks and local extinctions over the long term. We further (3) assessed the consequences of future climate for the fate of L.hyperborea using different scenarios of greenhouse gas emissions (RCP 2.6 and RCP 8.5). Results show NW Iberia, SW Ireland and W English Channel, Faroe Islands and S Iceland, as regions where L.hyperborea may have persisted during past climate extremes until present day. All predictions for the future showed expansions to northern territories coupled with the significant loss of suitable habitats at low latitude range margins, where long-term persistence was inferred (e.g., NW Iberia). This pattern was particularly evident in the most agressive scenario of climate change (RCP 8.5), likely driving major biodiversity loss, changes in ecosystem functioning and the impoverishment of the global gene pool of L.hyperborea. Because no genetic baseline is currently available for this species, our results may represent a first step in informing conservation and mitigation strategies. PMID:26608411

  15. Temper tantrums

    Acting-out behaviors ... 4, they rarely occur. Being tired, hungry, or sick, can make tantrums worse or more frequent. WHEN ... has ended. Temper tantrums are an attention-seeking behavior. One strategy to minimize the length and severity ...

  16. Temperate grasslands

    Alba, Christina

    Ipswich : Salem Press - EBSCO Publishing, 2013 - (Howarth, R.), s. 182-187 ISBN 978-1-4298-3813-9 Institutional support: RVO:67985939 Keywords : grassland * temperate biome * ecology Subject RIV: EF - Botanics

  17. Tawny Owl Strix aluco as a bioindicator of Barn Owl Tyto alba breeding and the effect of winter severity on Barn Owl reproduction

    Chausson A.; Henry I.; Ducret B.; Almasi A.; Roulin A.

    2014-01-01

    In the temperate zone, food availability and winter weather place serious constraints on European Barn Owl Tyto alba populations. Using data collected over 22years in a Swiss population, we analysed the influence of early pre-breeding food conditions and winter severity on between-year variations in population size and reproductive performance. To estimate pre-breeding food conditions, we attempted a novel approach based on an index that combines Tawny Owl Strix aluco reproductive parameters ...

  18. Disease in the dark: molecular characterization of Polychromophilus murinus in temperate zone bats revealed a worldwide distribution of this malaria-like disease.

    Megali, A; Yannic, G; Christe, P

    2011-03-01

    For a better understanding of the complex coevolutionary processes between hosts and parasites, accurate identification of the actors involved in the interaction is of fundamental importance. Blood parasites of the Order Haemosporidia, responsible for malaria, have become the focus of a broad range of studies in evolutionary biology. Interestingly, molecular-based studies on avian malaria have revealed much higher species diversity than previously inferred with morphology. Meanwhile, studies on bat haemosporidian have been largely neglected. In Europe, only one genus (Polychromophilus) and two species have been morphologically described. To evaluate the presence of potential cryptic species and parasite prevalence, we undertook a molecular characterization of Polychromophilus in temperate zone bats. We used a nested-PCR approach on the cytochrome b mitochondrial gene to detect the presence of parasites in 237 bats belonging to four different species and in the dipteran bat fly Nycteribia kolenatii, previously described as being the vector of Polychromophilus. Polychromophilus murinus was found in the four bat species and in the insect vector with prevalence ranging from 4% for Myotis myotis to 51% for M. daubentoni. By sequencing 682 bp, we then investigated the phylogenetic relationships of Polychromophilus to other published malarial lineages. Seven haplotypes were found, all very closely related, suggesting the presence of a single species in our samples. These haplotypes formed a well-defined clade together with Haemosporidia of tropical bats, revealing a worldwide distribution of this parasite mostly neglected by malarial studies since the 1980s. PMID:21073585

  19. Is a Universal Model of Organic Acidity Possible: Comparison of the Acid/base Properties of DOC in the Boreal, Temperate and Tropical Zones

    Hruska, J.; Kohler, S.; Laudon, H.; Probst, J.; Bishop, K.

    2004-05-01

    The acid/base properties of dissolved organic carbon (DOC) are an important feature of soil and surface waters. Large differences in the acid/base properties of DOC observed in different studies might be solely due to spatial and temporal differences. Different analytical techniques, however, may explain some of the observed differences. We used a combination of ion-exchange techniques, titration and surface water chemistry data to evaluate DOC character from two substantially different areas - the relatively pristine boreal zone of Sweden and the heavily acidified temperate zone of the Czech Republic. On average we found a significantly higher site density (amount of carboxylic groups per milligram of DOC) for the Swedish sites (10.2 microequivalent/mg DOC) compared to the Czech sites (8.8 microequivalent/mg DOC) measured in 1990s. This suggests a slightly higher buffering capacity for Swedish DOC. A tri-protic model of a type commonly incorporated in biogeochemical models was used for estimating the DOC dissociation properties. For Swedish sites the following constants were calibrated: pKa1=3.04, pKa2=4.51, pKa3=6.46, while the constants for Czech sites were pKa1=2.5, pKa2=4.42, pKa3=6.7. Despite differences in site density values, both models predict very similar dissociation and thus pH buffering by DOC in the environmentally important range of pH 3.5-5.0. Interestingly, very recent results showed an increased site density in some of the Czech sites to values of 10.4 microequivalent/mg DOC, almost identical to that valid for the boreal zone. Recent data from a tropical region of Kamerun indicate values of 10.9 microequivalent/mg DOC. These two observation suggest that the temporary heavy antropogenic acidification in the Czech sites had a measurable influence on acid/base properties of surface water DOC.

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

    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. - Deep-rooted wheat can recycle nitrate leached from maize root zone in winter wheat-summer maize rotation system

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

    Zhou Shunli [Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100094 (China)], E-mail: zhoushl@cau.edu.cn; Wu Yongcheng [Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100094 (China); College of Agronomy, Si Chuan Agricultural University, Yaan 625014 (China); Wang Zhimin [Key Laboratory of Crop Cultivation and Farming System, Ministry of Agriculture, College of Agronomy and Biotechnology, China Agricultural University, 2 West Yuanmingyuan Road, Beijing 100094 (China); Lu Laiqing; Wang Runzheng [Wuqiao Experimental Station, China Agricultural University, Hebei 061802 (China)

    2008-04-15

    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 {sup 15}N 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. - Deep-rooted wheat can recycle nitrate leached from maize root zone in winter wheat-summer maize rotation system.

  2. Toxic potencies of metabolite(s) of non-cylindrospermopsin producing Cylindrospermopsis raciborskii isolated from temperate zone in human white cells.

    Poniedzia?ek, Barbara; Rzymski, Piotr; Kokoci?ski, Miko?aj; Karczewski, Jacek

    2015-02-01

    Cylindrospermopsis raciborskii (Nostocales, Cyanobacteria) has worldwide distribution and is well known for producing the toxic alkaloid, cylindrospermopsin (CYN). Strains unable to synthesize this compound but potentially toxic were recently identified in Europe. Here, for the first time the effect of cell-free extracts of a non-CYN-producing strain of C. raciborskii was studied in human cells (neutrophils and lymphocytes) isolated from healthy donors. The observed effects were compared to those induced by CYN (1.0-0.01 ?g mL(-1)). Short-term (1h) extract treatments resulted in altered viability of cells demonstrated by increased necrosis and apoptosis in neutrophils and elevated apoptosis in lymphocytes. CYN did not induce similar effects, regardless of the toxin concentration. Exposure of T-lymphocytes to 100% C. raciborskii extract in isolated and whole-blood 72 h cultures resulted in decrease of proliferation by 20.6% and 32.5%, respectively. In comparison, exposure to 1.0 ?g mL(-1) of CYN caused lymphocytes proliferation to be inhibited by 91.0% in isolated cultures and 56.5% in whole-blood assay. Significant antiproliferative properties were also found for 0.1 ?g mL(-1) of CYN in whole-blood culture. From the results we conclude that strains occurring in temperate zones may pose a threat to human health through the production of hitherto unknown metabolites that reveal a toxic pattern different to that of CYN. At the same time our study demonstrates that CYN is a powerful but slowly-acting toxin in human immune cells. PMID:25462304

  3. Prey type and foraging ecology of Sanderlings Calidris alba in differentclimate zones: are tropical areas more favourable than temperate sites?

    Grond, K.; Ntiamoa-Baidu, Y.; Piersma, T.; Reneerkens, J.

    2015-01-01

    Sanderlings (Calidris alba) are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north te...

  4. Prey type and foraging ecology of Sanderlings Calidris alba in different climate zones: are tropical areas more favourable than temperate sites?

    Grond, Kirsten; Ntiamoa-Baidu, Yaa; Piersma, Theunis; Reneerkens, Jeroen

    2015-01-01

    Sanderlings (Calidris alba) are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north te...

  5. Winter to summer evolution of pCO2 in surface water and airsea CO2 flux in the seasonal ice zone of the Southern Ocean

    D. Nomura

    2014-01-01

    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 (6467 S, 3258 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, airsea 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 airsea CO2 flux becomes negative, such that in summer the study area is a CO2 sink with respect to the atmosphere.

  6. Occurrence of large temperature inversion in the thermohaline frontal zone at the Yellow Sea entrance in winter and its relation to advection

    Lie, Heung-Jae; Cho, Cheol-Ho; Jung, Kyung Tae

    2015-01-01

    inversion (higher temperature at a deeper depth) in winter and its relation to advection were investigated by analyzing both conductivity-temperature-depth data in the southern Yellow Sea (YS) and northwestern East China Sea during the winter of 2002-2003 and time series data of temperature, salinity, and currents at a buoy station at the YS entrance. Significant temperature inversions occur predominantly along the thermohaline front at the YS entrance where the Cheju Warm Current Water (CWCW) and the cold coastal waters meet. In February 2003, on the northern frontal zone along 34°N where isotherms and isohalines declined downward to the north, particularly large inversions with temperature differences of larger than 2.0°C were observed to occur more in troughs than in the crests of the wave-like frontal meander where the cold Korean coastal water (KCW) advances farther southward. The inversion persisted until mid-April at the buoy station in the frontal zone, and both temperature and salinity showed simultaneous variations in the same manner. During episodic occurrences of large inversions, temperature and salinity decreased sharply in the upper layer, but increased concurrently in the lower layer. These episodic inversions were found to be closely related to the westward advection of the KCW in the upper layer and the northward advection of the CWCW in the lower layer. It is considered that these advections may play an important role in maintaining baroclinicity in the northern frontal zone, which is responsible for driving the westward transversal flow across the YS entrance.

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

    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)

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

    Borras, A.; Senar, Juan Carlos; Francisca ALBA SÁNCHEZ; López Sáez, José Antonio; Cabrera, J.; Colomé, X.; Cabrera, T.

    2010-01-01

    [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...

  9. Tempered fractional calculus

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series

  10. Tempered fractional calculus

    Sabzikar, Farzad, E-mail: sabzika2@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Meerschaert, Mark M., E-mail: mcubed@stt.msu.edu [Department of Statistics and Probability, Michigan State University, East Lansing, MI 48823 (United States); Chen, Jinghua, E-mail: cjhdzdz@163.com [School of Sciences, Jimei University, Xiamen, Fujian, 361021 (China)

    2015-07-15

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  11. Tempered fractional calculus

    Sabzikar, Farzad; Meerschaert, Mark M.; Chen, Jinghua

    2015-07-01

    Fractional derivatives and integrals are convolutions with a power law. Multiplying by an exponential factor leads to tempered fractional derivatives and integrals. Tempered fractional diffusion equations, where the usual second derivative in space is replaced by a tempered fractional derivative, govern the limits of random walk models with an exponentially tempered power law jump distribution. The limiting tempered stable probability densities exhibit semi-heavy tails, which are commonly observed in finance. Tempered power law waiting times lead to tempered fractional time derivatives, which have proven useful in geophysics. The tempered fractional derivative or integral of a Brownian motion, called a tempered fractional Brownian motion, can exhibit semi-long range dependence. The increments of this process, called tempered fractional Gaussian noise, provide a useful new stochastic model for wind speed data. A tempered fractional difference forms the basis for numerical methods to solve tempered fractional diffusion equations, and it also provides a useful new correlation model in time series.

  12. Optimal foraging behavior and the thermal neutral zone of Peromyscus leucopus during winter: A test using natural and controlled ambient temperatures.

    St Juliana, Justin R; Mitchell, William A

    2016-02-01

    Endotherms foraging at temperatures outside of their thermal neutral zone (TNZ) pay an increased energetic cost. We asked if thermally-induced changes in foraging costs influence quitting harvest rate (QHR) of mice. We predicted that mice foraging during the winter would have a higher QHR in more costly colder conditions. We conducted our study with wild caught Peromyscus leucopus in an enclosure located in West Terre Haute, Indiana. We assayed changes in QHR using the forager's giving up density (GUD), which is the amount of uneaten seeds reaming in a tray after foraging activity. Each night from January 12th to March 13th, we assigned 4 trays as "cold trays" (at ambient temperature), and 4 trays as "hot trays" (trays with a ceramic heat element that increased the temperatures of feeding trays ca. 10-15°C). GUDs (and therfore QHRs) increased as a function of decreasing ambient temperature. Furthermore there was an interaction between tray temperature and ambient temperature; namely, on cool nights mice had lower GUDs in the "hot trays", but on warm nights mice had lower GUDs in the "cold trays". The TNZ for P. leucopus actively foraging during winter may be closer to the environmental average temperature than typically measured in the laboratory. Overall, these results support the idea that QHR is related to an animal's foraging in thermally challenged conditions. We present a unique way of measuring an animal's TNZ in the field using behavioral indicators. PMID:26857984

  13. Building energy saving potential in Hot Summer and Cold Winter (HSCW) Zone, China—Influence of building energy efficiency standards and implications

    Hot Summer and Cold Winter (HSCW) region plays an important role in China's building energy conservation task due to its high consumption in recent years for both climate and social reasons. National and local building energy standards according to which the buildings are built and operated can affect the building energy consumption to a great extent. This study investigated the energy saving potential in Hot Summer and Cold Winter Zone under different level of energy efficiency standards (China local, China national, and UK standard). Chongqing was taken as an example, and the commercial energy simulation tool eQuest was applied to analyze the building end-use energy. With the existing situation as a baseline, the building energy saving for residential section could achieve 31.5% if the Chinese national standard were satisfied, and the value would further increase to 45.0% and 53.4% when the Chongqing local and UK standard were met. For public buildings, the corresponding energy saving potentials were 62.8%, 67.4% and 75.9%. Parameter sensitivity analysis was conducted. The analysis was able to provide suggestions on energy saving implementation priorities for residential and public buildings. Indications to improve building energy standards and their implementation were also discussed. - Highlights: ► Building energy efficiency standards were compared among China, UK and the US. ► Heating energy consumption takes 1/3 of that of the residential building in HSCW Zone, China. ► Building energy saving in Chongqing is 30–70% applying various building standards. ► Public and residential buildings are most sensitive to LPD and COP respectively. ► Building energy standards should be improved and implementation should be enforced

  14. Tempering by Subsampling

    van de Meent, Jan-Willem; Paige, Brooks; Wood, Frank

    2014-01-01

    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 tempering by subsam...

  15. Second generation sequencing and morphological faecal analysis reveal unexpected foraging behaviour by Myotis nattereri (Chiroptera, Vespertilionidae) in winter

    Hope, Paul R; Bohmann, Kristine; Gilbert, M Thomas P; Zepeda-Mendoza, Marie Lisandra; Razgour, Orly; Jones, Gareth

    2014-01-01

    BACKGROUND: Temperate winters produce extreme energetic challenges for small insectivorous mammals. Some bat species inhabiting locations with mild temperate winters forage during brief inter-torpor normothermic periods of activity. However, the winter diet of bats in mild temperate locations is ...

  16. Prey type and foraging ecology of Sanderlings Calidris alba in different climate zones: are tropical areas more favourable than temperate sites?

    Grond, Kirsten; Ntiamoa-Baidu, Yaa; Piersma, Theunis; Reneerkens, Jeroen

    2015-01-01

    Sanderlings (Calidris alba) are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north temperate and a tropical non-breeding site in the Netherlands and Ghana, respectively. In both cases the birds used similar habitats (open beaches), and experienced similar periods of daylight, which enabled us to compare food abundance and availability, and behavioural time budgets and food intake. During the non-breeding season, Sanderlings in the Netherlands spent 79% of their day foraging; in Ghana birds spent only 38% of the daytime period foraging and the largest proportion of their time resting (58%). The main prey item in the Netherlands was the soft-bodied polychaete Scolelepis squamata, while Sanderlings in Ghana fed almost exclusively on the bivalve Donax pulchellus, which they swallowed whole and crushed internally. Average availability of polychaete worms in the Netherlands was 7.4 g ash free dry mass (AFDM) m(-2), which was one tenth of the 77.1 g AFDM m(-2) estimated for the beach in Ghana. In the tropical environment of Ghana the Sanderlings combined relatively low energy requirements with high prey intake rates (1.64 mg opposed to 0.13 mg AFDM s(-1) for Ghana and the Netherlands respectively). Although this may suggest that the Ghana beaches are the most favourable environment, processing the hard-shelled bivalve (D. pulchellus) which is the staple food could be costly. The large amount of daytime spent resting in Ghana may be indicative of the time needed to process the shell fragments, rather than indicate rest. PMID:26290790

  17. Prey type and foraging ecology of Sanderlings Calidris alba in different climate zones: are tropical areas more favourable than temperate sites?

    Ntiamoa-Baidu, Yaa; Piersma, Theunis; Reneerkens, Jeroen

    2015-01-01

    Sanderlings (Calidris alba) are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north temperate and a tropical non-breeding site in the Netherlands and Ghana, respectively. In both cases the birds used similar habitats (open beaches), and experienced similar periods of daylight, which enabled us to compare food abundance and availability, and behavioural time budgets and food intake. During the non-breeding season, Sanderlings in the Netherlands spent 79% of their day foraging; in Ghana birds spent only 38% of the daytime period foraging and the largest proportion of their time resting (58%). The main prey item in the Netherlands was the soft-bodied polychaete Scolelepis squamata, while Sanderlings in Ghana fed almost exclusively on the bivalve Donax pulchellus, which they swallowed whole and crushed internally. Average availability of polychaete worms in the Netherlands was 7.4 g ash free dry mass (AFDM) m?2, which was one tenth of the 77.1 g AFDM m?2 estimated for the beach in Ghana. In the tropical environment of Ghana the Sanderlings combined relatively low energy requirements with high prey intake rates (1.64 mg opposed to 0.13 mg AFDM s?1 for Ghana and the Netherlands respectively). Although this may suggest that the Ghana beaches are the most favourable environment, processing the hard-shelled bivalve (D. pulchellus) which is the staple food could be costly. The large amount of daytime spent resting in Ghana may be indicative of the time needed to process the shell fragments, rather than indicate rest. PMID:26290790

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

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

    2004-09-01

    Full Text Available Bajo condiciones actuales, extensas reas de las zonas templadas del oeste de Amrica del Norte y del sur de Amrica del Sur tienen regmenes climticos ridos a subhmedos, que son vulnerables a cambios climticos inducidos por actividades humanas. Predicciones obtenidas a partir de modelos de circ [...] ulacin global bajo una duplicacin del CO2 atmosfrico sugieren grandes cambios en temperatura media anual, y cambios pequeos o nulos en la precipitacin media anual y la proporcin de precipitacin estival. Nuestro objetivo fue evaluar cmo las predicciones de cambio climtico obtenidas de modelos de circulacin global influirn sobre los patrones climticos, e inferir a partir de ello la distribucin de los ecosistemas de las zonas templadas de Amrica del Norte y del Sur. Clculos de dficit hdrico anual sugieren que, debido al cambio climtico, se duplicar el rea afectada por condiciones muy secas. Esta expansin ocurrir en las cercanas de las zonas ridas actuales. Clculos mensuales de dficit hdrico sugieren que aproximadamente la mitad de la zona templada de cada continente se ve afectada por al menos un mes de dficit. Bajo un clima con doble CO2, estas reas se expandiran y cubriran hasta 77 % de las reas templadas de Amrica del Norte y hasta 80 % de Amrica del Sur. Los cambios en la distribucin de ecosistemas resultantes probablemente sern debidos a la expansin de los desiertos a expensas de los pastizales en Amrica del Norte y del Sur, y la expansin de los pastizales a expensas de los bosques deciduos y boreales en Amrica del Norte. Nuestros anlisis asumen que los cambios climticos futuros estarn abarcados por las predicciones de los tres escenarios de duplicacin de CO2 que utilizamos. La situacin ms probable es que los cambios reales, si es que ocurren, sern distintos a nuestros escenarios. Por lo tanto, nuestros anlisis debern interpretarse como indicaciones de la sensibilidad de partes de las zonas templadas de Amrica del Norte y del Sur a aumentos de temperatura. La principal conclusin de nuestros anlisis es que cualquier aumento de temperatura debido a cambios climticos resultar en una expansin de las porciones ms ridas 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 from our scenarios. Therefore, our analyses should be

  19. [Start-up Characteristics of Four-zone Integrated Reactor for Nitrogen Removal in Winter and Analysis of Nitrobacteria Community].

    Zhang, Yan; Sun, Feng-xia; Xie, Hang-ji; Chen, Jing; Sui, Xi; Gan, Zhi-ming; Wang, Xiu-ping; Shi, Yang

    2015-09-01

    The treatment of decentralized sewage has gained more and more attention in China in recent years. A four-zone integrated reactor was designed by combining biofilm system and activated sludge system and start-up by gradient shorten the HRT. The removal of COD, NH4+ -N and TN were studied at 8-15°C. Fluorescence in situ hybridization(FISH) was used to detect nitrobacteria population (AOB,NOB) so as to study the relationship between the reactor effect and functional micro-bacteria. The results showed that, when the HRT was 9.2 h, the removal efficiencies of COD, ammonia and TN were 92. 11%, 99. 21% and 61. 63%, respectively. Compared to the initial stage, the numbers of AOB and NOB in the late phase were increased by 5. 82 and 6. 14 times, respectively. In addition, the proportion of nitrobacteria was increased from 6. 12% to 16. 38% , which became the dominant bacteria in biofilms. Moreover, the nitrification efficiency was increased from 78. 49% to 97. 52% , while the number of NOB was 5. 61-fold increased and the value of AOB/NOB was optimized to 1. 47. The effluent quality is guaranteed by the enrichment of AOB and NOB and suitable value of AOB/NOB. PMID:26717696

  20. Off-season uptake of nitrogen in temperate heath vegetation

    Andresen, Louise Christoffersen; Michelsen, Anders

    2004-01-01

    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...... 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...

  1. Off-season uptake of nitrogen in temperate heath vegetation

    Andresen, Louise C.; Michelsen, Anders

    2005-01-01

    In this field study we show that temperate coastal heath vegetation has a significant off-season uptake potential for nitrogen, both in the form of ammonium and as glycine, throughout winter. We injected 15N-ammonium and 15N 2x(13C)-glycine into the soil twice during winter and once at spring. Th...... budgets of heath ecosystems, and the view of plant nutrient uptake as low in this climatic region during winter should be revised....

  2. 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

    W.K. LAUENROTH

    2004-09-01

    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 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

  3. Identification of paleo Arctic winter sea ice limits and the marginal ice zone: Optimised biomarker-based reconstructions of late Quaternary Arctic sea ice

    Belt, Simon T.; Cabedo-Sanz, Patricia; Smik, Lukas; Navarro-Rodriguez, Alba; Berben, Sarah M. P.; Knies, Jochen; Husum, Katrine

    2015-12-01

    Analysis of >100 surface sediments from across the Barents Sea has shown that the relative abundances of the mono-unsaturated sea ice diatom-derived biomarker IP25 and a tri-unsaturated highly branched isoprenoid (HBI) lipid (HBI III) are characteristic of the overlying surface oceanographic conditions, most notably, the location of the seasonal sea ice edge. Thus, while IP25 is generally limited to locations experiencing seasonal sea ice, with higher abundances found for locations with longer periods of ice cover, HBI III is found in sediments from all sampling locations, but is significantly enhanced in sediments within the vicinity of the retreating sea ice edge or marginal ice zone (MIZ). The response of HBI III to this well-defined sea ice scenario also appears to be more selective than that of the more generic phytoplankton biomarker, brassicasterol. The potential for the combined analysis of IP25 and HBI III to provide more detailed assessments of past sea ice conditions than IP25 alone has been investigated by quantifying both biomarkers in three marine downcore records from locations with contrasting modern sea ice settings. For sediment cores from the western Barents Sea (intermittent seasonal sea ice) and the northern Norwegian Sea (ice-free), high IP25 and low HBI III during the Younger Dryas (ca. 12.9-11.9 cal. kyr BP) is consistent with extensive sea cover, with relatively short periods of ice-free conditions resulting from late summer retreat. Towards the end of the YD (ca. 11.9-11.5 cal. kyr BP), a general amelioration of conditions resulted in a near winter maximum ice edge scenario for both locations, although this was somewhat variable, and the eventual transition to predominantly ice-free conditions was later for the western Barents Sea site (ca. 9.9 cal. kyr BP) compared to NW Norway (ca. 11.5 cal. kyr BP). For both locations, coeval elevated HBI III (but absent IP25) potentially provides further evidence for increased Atlantic Water inflow during the early Holocene, but this interpretation requires further investigation. In contrast, IP25 and HBI III data obtained from a core from the northern Barents Sea demonstrate that seasonal sea ice prevailed throughout the Holocene, but with a gradual shift from winter ice edge conditions during the early Holocene to more sustained ice cover in the Neoglacial; a directional shift that has undergone a reverse in the last ca. 150 yr according to observational records. Our combined surface and downcore datasets suggest that combined analysis of IP25 and HBI III can provide information on temporal variations in the position of the maximum (winter) Arctic sea ice extent, together with insights into sea ice seasonality by characterisation of the MIZ. Combining IP25 with HBI III in the form of the previously proposed PIP25 index yields similar outcomes to those obtained using brassicasterol as the phytoplankton marker. Importantly, however, some problems associated with use of a variable balance factor employed in the PIP25 calculation, are potentially alleviated using HBI III.

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

    Benjamin W. Tobin

    2013-09-01

    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.

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

    Stuart Phinn

    2011-05-01

    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.

  6. Winter Weather

    ... Additional Resources Emergency Preparedness and Response Other Natural Disasters/Severe Weather ... preparedness for and resilience against extreme weather. Winter weather presents hazards including ...

  7. Tempered distributions: does universal tempering procedure exist?

    Klebanov, Lev B; Slámová, Lenka

    2015-01-01

    Since the turn of the century, there has been increased interest in the application of heavy-tailed distributions, particularly stable distributions, to problems in physics and finance. Although, the tails of stable distributions provide a better fit to real-world data, they are too fat to describe empirical distributions. To remedy this drawback of stable distributions, so-called tempered variants of stable distributions have been proposed. In this paper, we argue that the tempering should b...

  8. Understory bamboo discrimination using a winter image

    Wang, T.; Skidmore, A.K.; A. G. Toxopeus; Liu, X.

    2009-01-01

    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...

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

    F. Renou-Wilson

    2014-04-01

    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.

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

    Renou-Wilson, F.; Barry, C.; Mller, C.; Wilson, D.

    2014-08-01

    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 (GHG) 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 2-year study of the net ecosystem carbon balance (NECB) of two such sites. We determined GHG fluxes and waterborne carbon (C) 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. Carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) fluxes 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 (233 g C m-2 yr-1), CH4 neutral, and a small source of N2O (0.16 g N2O-N m-2 yr-1). Net ecosystem exchange (NEE) at the shallow-drained nutrient-poor site was -89 and -99 g C m-2 yr-1 in Years 1 and 2 respectively, and NEE at the deep-drained nutrient-poor site was 85 and -26 g C m-2 yr-1 respectively. Low CH4 emissions (1.3 g C m-2 yr-1) were recorded at the shallow-drained nutrient-poor site. Fluvial exports from the nutrient-rich site totalled 69.8 g C m-2 yr-1 with 54% as dissolved organic C. Waterborne C losses from the nutrient-poor site reflected differences in annual runoff totalling 44 g C m-2 yr-1 in Year 1 and 30.8 g C m-2 yr-1 in Year 2. The NECB of the nutrient-rich grassland was 663 g C m-2 yr-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-2 yr-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-2 yr-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 were also significant factors which impacted 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.

  11. The Need for Temperance

    Karl Inge Tangen

    2015-11-01

    Full Text Available This article explores how temperance as a virtue relates to organizational leadership. The study begins with a short survey of classical Greek and Christian notions of temperance before proceeding to ex-plore temperance in relation to self-leadership, visionary and strategic leadership, and relational lead-ership. The final part of the article offers reflections on how temperance might be cultivated from a theological perspective. Temperance is understood not only as sound thinking but also as embodied self-control and active patience. On the level of self-leadership, it is argued that temperance enables the leader to establish forms of integrity that protect the leader’s self from chaos and destruction. Moreover, temperance may also nurture focused visionary leadership that accepts ethical limits and has an eye to the common good. The study also suggests that organizations should cultivate a culture of strategic discipline that is capable of realizing such visions. On the interpersonal level, temperance is viewed as critical in terms of enabling leaders to treat co-workers with respect and wisdom and han-dle conflict with consideration. Finally, is argued that that the cultivation of temperance is not a one-way street from the inside to the outside or a subordination of feelings to reason but rather a very complex process that includes interpersonal humility, finds vision in an encounter with the good, and yet remains a personal responsibility.

  12. 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

    Osvaldo J Vidal; Jan R. Bannister; VÍCTOR SANDOVAL; YESSICA PÉREZ; CARLOS RAMÍREZ

    2011-01-01

    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. Classification (cluster analysis) and ordination (principal component analysis) techniques were used to segregate and examine the communities. Biodiversity indicators including richness and abundance...

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

    Alexandre Couto Rodrigues

    2005-04-01

    Full Text Available 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 climáticas, 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.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 climatic 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.

  14. Accelerated simulated tempering

    We propose a new stochastic global optimization method by accelerating the simulated tempering scheme with random walks executed on a temperature ladder with various transition step sizes. By suitably choosing the length of the transition steps, the accelerated scheme enables the search process to execute large jumps and escape entrapment in local minima, while retaining the capability to explore local details, whenever warranted. Our simulations confirm the expected improvements and show that the accelerated simulated tempering scheme has a much faster convergence to the target distribution than Geyer and Thompson's simulated tempering algorithm and exhibits accuracy comparable to the simulated annealing method

  15. Accelerated simulated tempering

    Li, Yaohang; Protopopescu, Vladimir A.; Gorin, Andrey

    2004-08-01

    We propose a new stochastic global optimization method by accelerating the simulated tempering scheme with random walks executed on a temperature ladder with various transition step sizes. By suitably choosing the length of the transition steps, the accelerated scheme enables the search process to execute large jumps and escape entrapment in local minima, while retaining the capability to explore local details, whenever warranted. Our simulations confirm the expected improvements and show that the accelerated simulated tempering scheme has a much faster convergence to the target distribution than Geyer and Thompson's simulated tempering algorithm and exhibits accuracy comparable to the simulated annealing method.

  16. 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

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

    2004-01-01

    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...

  17. Polynomial tempered distributions

    Sharyn S.V.

    2010-01-01

    In the article polynomial (nonlinear) analogue of tempered Schwartz distributions is constructed. Generalized operation of differentiation in the space of polynomial generalized functions as well as Fourier-Laplace transformation of such distributions are considered. Some examples are given.

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

    Hahn, Ina H; Grynderup, Matias Brødsgaard; Dalsgaard, Sofie B; Thomsen, Jane F; Hansen, Åse Marie; Kærgaard, Anette; Kærlev, Linda; Mors, Ole; Rugulies, Reiner; Mikkelsen, Sigurd; Bonde, Jens Peter; Kolstad, Henrik

    2011-01-01

    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....

  19. Inverse Tempered Stable Subordinators

    Kumar, A.; P. Vellaisamy

    2014-01-01

    We consider the first-hitting time of a tempered $\\beta$-stable subordinator, also called inverse tempered stable (ITS) subordinator. The density function of the ITS subordinator is obtained, for the index of stability $\\beta \\in (0,1)$. The series representation of the ITS density is also obtained, which could be helpful for computational purposes. The asymptotic behaviors of the $q$-th order moments of the ITS subordinator are investigated. In particular, the limiting behaviors of the mean ...

  20. Irreversible simulated tempering

    Sakai, Yuji; Hukushima, Koji

    2016-01-01

    An extended ensemble Monte Carlo algorithm is proposed by introducing a violation of the detailed balance condition to the update scheme of the inverse temperature in simulated tempering. Our method, irreversible simulated tempering, is constructed based on the framework of the skew detailed balance condition. By applying this method to the ferromagnetic Ising model in two dimensions on a square lattice as a benchmark, the dynamical behavior of the inverse temperature and an autocorrelation f...

  1. Patrones geográficos de distribuci��n de árboles y arbustos en la zona de transición climática mediterráneo-templada de Chile Geographic patterns of distribution of trees and shrubs in the transitional Mediterranean-temperate climatic zone of Chile

    ERNESTO A. TENEB

    2004-03-01

    Full Text Available Uno de los principales objetivos de la biogeografía es determinar si las especies se distribuyen en el espacio en forma aleatoria o si existen grupos de especies con patrones de distribución comunes. En el presente estudio determinamos a través de técnicas cuantitativas si existen corotipos, es decir, grupos de especies con patrones de distribución común entre los árboles y arbustos en la zona de transición climática mediterráneo-templada de Chile, Octava Región de Chile. Adicionalmente, evaluamos la relación entre el clima y la distribución de los diferentes grupos de árboles y arbustos de la Octava Región. El análisis de agrupamiento de especies permitió definir 24 corotipos significativos, de los cuales 18 responden significativamente con alguna variable ambiental analizada. La temperatura media anual, la temperatura media invernal y la temperatura media de verano resultaron ser las variables que mejor explican el patrón de distribución de la mayoría de los corotipos. Las tendencias geográficas de los corotipos y su relación con las variables ambientales fueron evaluadas mediante un análisis de ordenación. Los resultados señalan que los corotipos con distribución en la cordillera de los Andes se correlacionan con la temperatura de invierno en tanto que los corotipos con distribución costera se correlacionan con la mediterraneidad. Se discute respecto de la utilización de una nueva aproximación para el análisis fitogeográfico y de su utilidad en el estudio de la relación entre la vegetación y los factores ambientales que determinan su distribuciónOne main aim of biogeography is to determine if species are randomly distributed or if there exist groups of species with common distributional patterns known as chorotypes. In this study, we determined through quantitative techniques if there exists such chorotypes for trees and shrubs in the transitional Mediterranean-temperate climatic zone of Chile, Eigth Administrative Region of Chile. Additionally, we evaluated the relationship between climate and distribution of the different chorotypes. The analyses allowed defining 24 significant chorotypes, 18 of which were significantly associated with some used environmental variable. Mean annual temperature, mean summer temperature and mean winter temperature were the variables that explained the distribution of most of the chorotypes. The geographic tendencies of chorotypes and their relationship with environmental variables were evaluated with canonical correspondence analysis. The results indicated that chorotypes distributed in the Andes Range were correlated with the mean winter temperature, whereas chorotypes with coastal distribution were correlated with mediterreanity. We discusses the use of new approaches for phytogeographic analysis and its utility in the study of the relationship between vegetation and environmental factors that determine its distribution

  2. Greater understanding is need of whether warmer and shorter winters associated with climate change could reduce winter mortality

    Ebi, Kristie L.

    2015-11-01

    In temperate regions, mortality is higher during winter than summer seasons. Assuming this seasonality is associated with ambient temperature, assessments often conclude that climate change will likely reduce winter mortality. However, there has been limited evaluation of the extent to which cold temperatures are actually the proximal cause of winter mortality in temperate regions. Kinney et al (2015 Environ Res. Lett. 10 064016) analyzed multi-decadal data from 39 cities in the US and France and concluded that cold temperatures are not a primary driver of most winter excess mortality. These analyses suggest that increases in heat-related mortality with climate change will unlikely be balanced by reductions in winter mortality, reinforcing the importance of health systems continuing to ensure adequate health protection against cold temperatures even as temperatures warm.

  3. Simulated Solute Tempering.

    Denschlag, Robert; Lingenheil, Martin; Tavan, Paul; Mathias, Gerald

    2009-10-13

    For the enhanced conformational sampling in molecular dynamics (MD) simulations, we present "simulated solute tempering" (SST) which is an easy to implement variant of simulated tempering. SST extends conventional simulated tempering (CST) by key concepts of "replica exchange with solute tempering" (REST, Liu et al. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 13749). We have applied SST, CST, and REST to molecular dynamics (MD) simulations of an alanine octapeptide in explicit water. The weight parameters required for CST and SST are determined by two different formulas whose performance is compared. For SST only one of them yields a uniform sampling of the temperature space. Compared to CST and REST, SST provides the highest exchange probabilities between neighboring rungs in the temperature ladder. Concomitantly, SST leads to the fastest diffusion of the simulation system through the temperature space, in particular, if the "even-odd" exchange scheme is employed in SST. As a result, SST exhibits the highest sampling speed of the investigated tempering methods. PMID:26631796

  4. Choosing weights for simulated tempering

    Park, Sanghyun; Pande, Vijay S.

    2007-07-01

    Simulated tempering is a method to enhance simulations of complex systems by periodically raising and lowering the temperature. Despite its advantages, simulated tempering has been overshadowed by its parallel counterpart, replica exchange (also known as parallel tempering), due to the difficulty of weight determination in simulated tempering. Here we propose a simple and fast method to obtain near-optimal weights for simulated tempering, and demonstrate its effectiveness in a molecular dynamics simulation of Ala10 polypeptide in explicit solvent. We believe simulated tempering now deserves another look.

  5. Summer-restricted migration of green turtles Chelonia mydas to a temperate habitat of the northwest Pacific Ocean

    FUKUOKA, T; Narazaki, T.; Sato, K

    2015-01-01

    The foraging habitats of green turtles Chelonia mydas range from tropical to temperate areas. Previous studies have generally been biased toward tropical and sub-tropical areas; hence, available data do not accurately describe the species' foraging activity in temperate areas. To reveal seasonal patterns of habitat use in temperate areas, we conducted a by-catch survey, a mark-recapture study, and satellite tracking of green turtles along the Sanriku Coast, a temperate zone in the northwest P...

  6. Study of the occurence of reversible temper embrittlement in the coarse-grained overheated structure of the heat-affected zone of steel 22 NiMoCr 37

    On four melts of steel 22 NiMoC 37 with about 0.22% C,0.3% Si, 0.9% Mn, 0.5% Cr, 0.78% Mo and 1% Ni, but different contents of phosphorus, sulphur, arsenic, copper, antimony and tin, the toughness behaviour in fine-grained quenched and tempered condition and also in coarse-grained overheated condition has been investigated in the notched-bar impact bend test as a function of the cooling rate after tempering or stress relieving. In fine-grained condition, the toughness behaviour changed only slightly. In the coarse-grained condition, the transition temperature increased considerably with increasing contents of trace elements and decreasing cooling rate. With 0.015% P, 0.012% As and 0.006% Sn, the increase of the transition temperature in the coarse-grained condition and at an average cooling rate of 30 K/h was with ?Tsub(trans) = 25 K still relatively low. With higher contents of phosphorus and tin, however, an increase of the transition temperature up to ?Tsub(trans) = 145 K was observed. Copper alone did not lead in the performed test series to any impairment of the notched-bar impact energy. In coarse-grained condition, temper embrittlement was proved also metallographically by etching with xylene picric acid solution. Segregation lines proved to be especially susceptible. In temper embrittled condition, the notched-bar impact bend test specimens showed an intercrystalline fracture appearance in the lower shelf and the transition range of the notched-bar impact energy-temperature curves. The examination of such fracture surfaces with the Auger probe revealed in an about 10-4 mm large grain boundary region the expected concentrations of the elements phosphorus, tin and nickel, but also an enrichment of copper. Especially the elements phosphorus and tin contributed to the reversible temper embrittlement of the coarse-grained overheated structure. (orig.)

  7. Adaptive parallel tempering algorithm

    Miasojedow, Blazej; Moulines, Eric; Vihola, Matti

    2012-01-01

    Parallel tempering is a generic Markov chain Monte Carlo sampling method which allows good mixing with multimodal target distributions, where conventional Metropolis-Hastings algorithms often fail. The mixing properties of the sampler depend strongly on the choice of tuning parameters, such as the temperature schedule and the proposal distribution used for local exploration. We propose an adaptive algorithm which tunes both the temperature schedule and the parameters of the random-walk Metrop...

  8. Winter severity determines functional trait composition of phytoplankton in seasonally ice-covered lakes.

    zkundakci, Deniz; Gsell, Alena S; Hintze, Thomas; Tuscher, Helgard; Adrian, Rita

    2016-01-01

    How climate change will affect the community dynamics and functionality of lake ecosystems during winter is still little understood. This is also true for phytoplankton in seasonally ice-covered temperate lakes which are particularly vulnerable to the presence or absence of ice. We examined changes in pelagic phytoplankton winter community structure in a north temperate lake (Mggelsee, Germany), covering 18 winters between 1995 and 2013. We tested how phytoplankton taxa composition varied along a winter-severity gradient and to what extent winter severity shaped the functional trait composition of overwintering phytoplankton communities using multivariate statistical analyses and a functional trait-based approach. We hypothesized that overwintering phytoplankton communities are dominated by taxa with trait combinations corresponding to the prevailing winter water column conditions, using ice thickness measurements as a winter-severity indicator. Winter severity had little effect on univariate diversity indicators (taxon richness and evenness), but a strong relationship was found between the phytoplankton community structure and winter severity when taxon trait identity was taken into account. Species responses to winter severity were mediated by the key functional traits: motility, nutritional mode, and the ability to form resting stages. Accordingly, one or the other of two functional groups dominated the phytoplankton biomass during mild winters (i.e., thin or no ice cover; phototrophic taxa) or severe winters (i.e., thick ice cover; exclusively motile taxa). Based on predicted milder winters for temperate regions and a reduction in ice-cover durations, phytoplankton communities during winter can be expected to comprise taxa that have a relative advantage when the water column is well mixed (i.e., need not be motile) and light is less limiting (i.e., need not be mixotrophic). A potential implication of this result is that winter severity promotes different communities at the vernal equinox, which may have different nutritional quality for the next trophic level and ecosystem-scale effects. PMID:26342133

  9. Winter ecology of shallow lakes: strongest effect of fish on water clarity at high nutrient levels

    Srensen, Torben; MULDERIJ Gabi; Sndergaard, Martin; LAURIDSEN Toben L.; LIBORIUSSEN Lone; BRUCET SANDRA; Jeppesen, Erik

    2010-01-01

    While the structuring role of fish in lakes is well studied for the summer season in North temperate lakes, little is known about their role in winter when fish activity and light irradiance potentially are lower. This is unfortunate as the progressing climate change may have strong effects on lake winter temperature and possibly on trophic dynamics too. We conducted an enclosure experiment with and without the presence of fish throughout winter in two shallow lakes with contrasting phosphoru...

  10. Seasonal dynamics of nitrogen fixation and the diazotroph community in the temperate coastal region of the northwestern North Pacific

    Shiozaki, T.; Nagata, T.; Ijichi, M.; Furuya, K.

    2015-01-01

    Nitrogen fixation in temperate oceans is a potentially important, but poorly understood process that may influence the marine nitrogen budget. This study determined seasonal variations in nitrogen fixation and nifH gene diversity within the euphotic zone in the temperate coastal region of the northwestern North Pacific. Nitrogen fixation as high as 13.6 nmolN L-1 d-1 was measured from early summer to fall when the surface temperature exceeded 14.2 C and the surface nitrate concentration was low (? 0.30 ?M), although we also detected nitrogen fixation in subsurface layers (42-62 m) where nitrate concentrations were high (> 1 ?M). During periods with high nitrogen fixation, the nifH sequences of UCYN-A were recovered, suggesting that these groups played a key role in nitrogen fixation. The nifH genes were also recovered in spring and winter when nitrogen fixation was undetectable. These genes consisted of many sequences affiliated with Cluster III diazotrophs (putative anaerobic bacteria), which hitherto have rarely been reported to be abundant in surface diazotroph communities in marine environments.

  11. Considerations about tempered martensite embrittlement

    There have been many quite meritorious studies made about the present subject. However, there are still some open questions: whether the mechanism of plastic deformation is the same in the Charpy test and in the slow static test, and what is the effect of the rate of work-hardening. The material selected for the tests was a common Cr-Mo steel. The long time tempering was carried out in a salt bath. A welding simulator was applied for the very short tempering. The stress-strain curves at some interesting tempering temperatures were determined by torsion tests. The Charpy impact tests were accomplished using V and U shaped specimens. The deformation and fracture of the specimen were studied with optical and scanning electron microscopes. There was no tempered martensite embrittlement in the specimens in the very short tempering time. (orig.)

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

    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

    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

  13. Transfer parameter values in temperate forest ecosystems: a review.

    Calmon, Philippe; Thiry, Yves; Zibold, Gregor; Rantavaara, Aino; Fesenko, Sergei

    2009-09-01

    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 (T(ag) in m(2)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 T(ag) values was 10(-3)m(2)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 T(ag), from 10(-3) to 10(1)m(2)kg(-1) (dry weight). For berries, typical values are around 0.01-0.1 m(2)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 T(ag) value of 0.01 m(2)kg(-1) (fresh weight) is common for (137)Cs in the muscles of adult moose and terrestrial birds living in boreal forests, and 0.03 m(2)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 T(ag) values for winter ranging from 0.02 to 0.8 m(2)kg(-1) (fresh weight), and in summer from 0.04 to 0.4m(2)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 (137)Cs has been found, with T(ag) values changing from 0.01 to 0.002 m(2)kg(-1) (fresh weight) in the three years after the contaminating event, the rate being determined by the dynamics of (137)Cs in aquatic ecosystems. PMID:19100665

  14. Transfer parameter values in temperate forest ecosystems: a review

    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.

  15. Employment and winter construction

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig

    2011-01-01

    possibilities exist for reducing seasonal variation in employment? In addition to a literature review related to winter construction, European and national employment and meteorological data were studied. Finally, ministerial acts, ministerial orders or other public policy documents related to winter...

  16. Winter Weather Emergencies

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

  17. Concussion in Winter Sports

    ... Button Past Emails CDC Features Concussion in Winter Sports Recommend on Facebook Tweet Share Compartir Get prepared ... to enjoy, practice, and compete in various winter sports. There's no doubt that these sports are a ...

  18. Adaptation to temperate climates.

    Bradshaw, William E; Zani, Peter A; Holzapfel, Christina M

    2004-08-01

    Only model organisms live in a world of endless summer. Fitness at temperate latitudes reflects the ability of organisms in nature to exploit the favorable season, to mitigate the effects of the unfavorable season, and to make the timely switch from one life style to the other. Herein, we define fitness as Ry, the year-long cohort replacement rate across all four seasons, of the mosquito, Wyeomyia smithii, reared in its natural microhabitat in processor-controlled environment rooms. First, we exposed cohorts of W. smithii, from southern, midlatitude, and northern populations (30-50 degrees N) to southern and northern thermal years during which we factored out evolved differences in photoperiodic response. We found clear evidence of evolved differences in heat and cold tolerance among populations. Relative cold tolerance of northern populations became apparent when populations were stressed to the brink of extinction; relative heat tolerance of southern populations became apparent when the adverse effects of heat could accumulate over several generations. Second, we exposed southern, midlatitude, and northern populations to natural, midlatitude day lengths in a thermally benign midlatitude thermal year. We found that evolved differences in photoperiodic response (1) prevented the timely entry of southern populations into diapause resulting in a 74% decline in fitness, and (2) forced northern populations to endure a warm-season diapause resulting in an 88% decline in fitness. We argue that reciprocal transplants across latitudes in nature always confound the effects of the thermal and photic environment on fitness. Yet, to our knowledge, no one has previously held the thermal year constant while varying the photic year. This distinction is crucial in evaluating the potential impact of climate change. Because global warming in the Northern Hemisphere is proceeding faster at northern than at southern latitudes and because this change represents an amelioration of the thermal environment and a concomitant increase in the duration of the growing season, we conclude that there should be more rapid evolution of photoperiodic response than of thermal tolerance as a consequence of global warming among northern, temperate ectotherms. PMID:15446427

  19. Simulating the Effect of Climate Change on Vegetation Zone Distribution on the Loess Plateau, Northwest China

    Guoqing Li

    2015-06-01

    Full Text Available A risk assessment of vegetation zone responses to climate change was conducted using the classical Holdridge life zone model on the Loess Plateau of Northwest China. The results show that there are currently ten vegetation zones occurring on the Loess Plateau (19502000, including alvar desert, alpine wet tundra, alpine rain tundra, boreal moist forest, boreal wet forest, cool temperate desert, cool temperate desert scrub, cool temperate steppe, cool temperate moist forest, warm temperate desert scrub, warm temperate thorn steppe, and warm temperate dry forest. Seventy years later (2070S, the alvar desert, the alpine wet tundra and the cool temperate desert will disappear, while warm temperate desert scrub and warm temperate thorn steppe will emerge. The area proportion of warm temperate dry forest will expand from 12.2% to 22.8%37.2%, while that of cool temperate moist forest will decrease from 18.5% to 6.9%9.5%. The area proportion of cool temperate steppe will decrease from 51.8% to 34.5%51.6%. Our results suggest that future climate change will be conducive to the growth and expansion of forest zones on the Loess Plateau, which can provide valuable reference information for regional vegetation restoration planning and adaptive strategies in this region.

  20. PAWL-Forced Simulated Tempering

    Bornn, Luke

    2013-01-01

    In this short note, we show how the parallel adaptive Wang-Landau (PAWL) algorithm of Bornn et al. (2013) can be used to automate and improve simulated tempering algorithms. While Wang-Landau and other stochastic approximation methods have frequently been applied within the simulated tempering framework, this note demonstrates through a simple example the additional improvements brought about by parallelization, adaptive proposals and automated bin splitting.

  1. Virtual-move Parallel Tempering

    Frenkel, Ivan Coluzza Daan

    2005-01-01

    We report a novel Monte Carlo scheme that greatly enhances the power of parallel-tempering simulations. In this method, we boost the accumulation of statistical averages by including information about all potential parallel tempering trial moves, rather than just those trial moves that are accepted. As a test, we compute the free-energy landscape for conformational changes in simple model proteins. With the new technique, the sampled region of the configurational space in which the free-energ...

  2. Winter Activity and Diapause of Aedes albopictus (Diptera: Culicidae) in Hanoi, Northern Vietnam.

    Tsunoda, Takashi; Chaves, Luis Fernando; Nguyen, Giang Thi Tra; Nguyen, Yen Thi; Takagi, Masahiro

    2015-11-01

    We studied the winter activity of Aedes albopictus (Skuse) from November 2008 to April 2009 in Bat Trang village of Hanoi, Vietnam. We selected 12 houses and collected: 1) adults with BG sentinel traps, 2) pupae from household water containers, and 3) eggs with ovitraps. Aedes albopictus adults, pupae, and eggs were not collected from early January to early February. Though the egg hatching probability tended to be initially high at longer day length, the maximum probability gradually shifted to shorter day length, as the observation period elapsed. When females were reared under long day length and their eggs were immersed 1 or 5 wk after oviposition, >50% of eggs hatched within 20 days. However, when females were reared under short day length and their eggs were immersed after 1 wk, hatching was suppressed for 60 days. When females were reared under short day length, the median hatching day occurred earlier in eggs kept dry for 5 and 10 wk after oviposition than in those dried for only 1 wk. This indicates that the extended dry periods accelerate egg hatching. Our results showed that hatchability gradually changed with day length, suggesting that selection for overwintering is not as strong relative to Ae. albopictus living in the temperate zone, where winter conditions are less favorable than in tropical and subtropical areas. PMID:26336261

  3. Shifts in Köppen-Geiger climate zones over southern Africa in relation to key global temperature goals

    Engelbrecht, Christien J.; Engelbrecht, Francois A.

    2016-01-01

    Potential changes in Köppen-Geiger climate zones over southern Africa (Africa south of 22 °S) under future climate change are investigated using an ensemble of high-resolution projections of a regional climate model. The projections are performed under the A2 scenario of the Special Report on Emission Scenarios (SRES), and changes are presented for those times in the future when the increase in global average surface temperature reaches thresholds of 1, 2, and 3 °C, relative to the present-day baseline climatology. Widespread shifts in climate regimes are projected, of which the southern and eastern expansion of the hot desert and hot steppe zones is the most prominent. From occupying 33.1 and 19.4 % of southern Africa under present-day climate, these regions are projected to occupy between 47.3 and 59.7 % (hot desert zone) and 24.9 and 29.9 % (hot steppe zone) of the region in a future world where the global temperature has increased by 3 °C. The cold desert and cold steppe zones are projected to decrease correspondingly. The temperate regions of eastern South Africa, the Cape south coast, and winter rainfall region of the southwestern Cape are also projected to contract. An expansion of the hot steppe zone into the cold steppe and temperate zones may favor the intrusion of trees (and therefore the savanna biome) into the most pristine grasslands of southern Africa. However, the correlative climate-vegetation approach of using projected changes in Köppen-Geiger zones to infer future vegetation patterns is of limited value in the savanna complex of southern Africa, where complex feedbacks occur between carbon dioxide (CO2) concentrations, trees, C4 grasses, fire, and climate. The present-day temperate Cape Fynbos regime may come under increasing pressure as the encompassing temperate zone is invaded mainly from the east by the hot steppe climate regime under climate change, with the incidence of Fynbos fires also becoming more likely in a generally warmer and drier climate.

  4. Time-temperature equivalence in Martensite tempering

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

    2008-06-16

    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.

  5. Internal strains after recovery of hardness in tempered martensitic steels for fusion reactors

    After tempering, with recovery of hardness, MANET steels present internal strains; these residual strains increase with quenching rate prior to tempering, and they remain after prolonged tempering times. On account of their persistence, after thermal treatments which lead to low dislocation and sub-boundary densities, the possibility has been considered that the high swelling resistance of MANET is connected with these centres of strain, probably connected with the formation, in ferrite, of Cr-enriched and contiguous Cr-depleted zones which may act as sinks for interstitials. Comparative observations on the internal strain behaviour of cold worked 316 L stainless steel appear consistent with this possibility. (orig.)

  6. Diversity and abundance of photosynthetic sponges in temperate Western Australia

    Brümmer Franz

    2009-02-01

    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.

  7. Winter reproduction in the greater mouse-eared bat (Myotis myotis) in South Iberia

    Ibáñez, Carlos

    1997-01-01

    One of the characteristics shared by temperate zone bats is the ability to delay reproductive events (such as ovulation and fertilization and, more rarely, implantation). It has been suggested in different vertebrate groups that these delays allow the females to time copulation and birth optimally in order to obtain the best quality mates (Birkhead & MØller, 1993). In accordance with this hypothesis, mating takes place in autumn in temperate zone bats, when males are in good physical conditio...

  8. Winters fuels report

    NONE

    1995-10-27

    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.

  9. 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

    Rodrigo J, Gonalves; Mara Sol, Souza; Juana, Aigo; Beatriz, Modenutti; Esteban, Balseiro; Virginia E, Villafae; Vctor, Cussac; E Walter, Helbling.

    2010-08-01

    Full Text Available En las ltimas dcadas, tanto la temperatura como la radiacin 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 acuticos, pero ahora el campo d [...] e estudio se ampla a medida que cobra importancia la combinacin 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 dulceacucola y peces de latitudes medias (definidas como aquellas comprendidas entre 30 y 60), especialmente en la regin Patagnica, debido a las caractersticas particulares de estas regiones. La RUV afecta (en general, negativamente) casi todos los procesos, desde la fijacin de carbono hasta el comportamiento y ciertamente todos los niveles trficos dentro del plancton, desde virus hasta larvas de peces. El mayor efecto negativo de la RUV es probablemente la accin mutagnica de la UVB, la cual afecta un nmero de procesos tales como fotosntesis, crecimiento y divisin celular, entre muchos otros. En los metazoos, la RUV puede ser un factor de estrs que afecta la supervivencia, o bien puede mostrar efectos subletales tales como en el comportamiento y alimentacin. Es difcil extraer un patrn general en cuanto a las respuestas, aun dentro de un grupo de organismos, ya que stas son generalmente especie-especficas y estn fuertemente influenciadas por condiciones locales (e.g., penetracin de la RUV, relacin PAR/RUV y aclimatacin). A pesar de que en muchos casos se han determinado efectos significativos, muchos organismos tambin disponen de mecanismos para evitar o minimizar el dao 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 ms importante que determina la distribucin del hbitat, y por lo tanto la biogeografa 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 climticos (incluyendo la recuperacin de la capa de ozono y el aumento de la temperatura durante las prximas dcadas) sern necesarias ms investigaciones combinando RUV y temperatura para entender las respuestas de los ecosistemas acuticos 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 30-60), 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, this may not hold true for global temperature changes. In

  10. Novel psychrotolerant picocyanobacteria isolated from Chesapeake Bay in the winter.

    Xu, Yongle; Jiao, Nianzhi; Chen, Feng

    2015-08-01

    Picocyanobacteria are major primary producers in the ocean, especially in the tropical or subtropical oceans or during warm seasons. Many "warm" picocyanobacterial species have been isolated and characterized. However, picocyanobacteria in cold environments or cold seasons are much less studied. In general, little is known about the taxonomy and ecophysiology of picocyanobacteria living in the winter. In this study, 17 strains of picocyanobacteria were isolated from Chesapeake Bay, a temperate estuarine ecosystem, during the winter months. These winter isolates belong to five distinct phylogenetic lineages, and are distinct from the picocyanobacteria previously isolated from the warm seasons. The vast majority of the winter isolates were closely related to picocyanobacteria isolated from other cold environments like Arctic or subalpine waters. The winter picocyanobacterial isolates were able to maintain slow growth or prolonged dormancy at 4°C. Interestingly, the phycoerythrin-rich strains outperformed the phycocyanin-rich strains at cold temperature. In addition, winter picocyanobacteria changed their morphology when cultivated at 4°C. The close phylogenetic relationship between the winter picocyanobacteria and the picocyanobacteria living in high latitude cold regions indicates that low temperature locations select specific ecotypes of picocyanobacteria. PMID:26986796

  11. Gradient Tempering Of Bearing Races

    Parr, Richardson A.

    1991-01-01

    Gradient-tempering process increases fracture toughness and resistance to stress-corrosion cracking of ball-bearing races made of hard, strong steels and subject to high installation stresses and operation in corrosive media. Also used in other applications in which local toughening of high-strength/low-toughness materials required.

  12. Speeding up parallel tempering simulations

    Hasenbusch, Martin; Schaefer, Stefan

    2010-01-01

    We discuss methods that allow to increase the step-size in a parallel tempering simulation of statistical models and test them at the example of the three-dimensional Heisenberg spin glass. We find an overall speed-up of about two for contemporary lattices.

  13. Discovering the Ancient Temperate Rainforest.

    Lindsay, Anne

    1997-01-01

    Two activities for grades 3 through 8 explore species adaptation and forestry issues in the North American rainforests. In one activity, students create imaginary species of plants or animals that are adapted for life in an ancient temperate rainforest. In the second activity, students role play groups affected by plans to log an area of the…

  14. Chilling and heat requirements for flowering in temperate fruit trees

    Guo, Liang; Dai, Junhu; Ranjitkar, Sailesh; Yu, Haiying; Xu, Jianchu; Luedeling, Eike

    2014-08-01

    Climate change has affected the rates of chilling and heat accumulation, which are vital for flowering and production, in temperate fruit trees, but few studies have been conducted in the cold-winter climates of East Asia. To evaluate tree responses to variation in chill and heat accumulation rates, partial least squares regression was used to correlate first flowering dates of chestnut ( Castanea mollissima Blume) and jujube ( Zizyphus jujube Mill.) in Beijing, China, with daily chill and heat accumulation between 1963 and 2008. The Dynamic Model and the Growing Degree Hour Model were used to convert daily records of minimum and maximum temperature into horticulturally meaningful metrics. Regression analyses identified the chilling and forcing periods for chestnut and jujube. The forcing periods started when half the chilling requirements were fulfilled. Over the past 50 years, heat accumulation during tree dormancy increased significantly, while chill accumulation remained relatively stable for both species. Heat accumulation was the main driver of bloom timing, with effects of variation in chill accumulation negligible in Beijing's cold-winter climate. It does not seem likely that reductions in chill will have a major effect on the studied species in Beijing in the near future. Such problems are much more likely for trees grown in locations that are substantially warmer than their native habitats, such as temperate species in the subtropics and tropics.

  15. Winters fuels report

    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

  16. 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

    Margarita Casas Valdez

    2008-08-01

    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.

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

    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

    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)

  18. Continuous Tempering Molecular Dynamics: A Deterministic Approach to Simulated Tempering.

    Lenner, Nicolas; Mathias, Gerald

    2016-02-01

    Continuous tempering molecular dynamics (CTMD) generalizes simulated tempering (ST) to a continuous temperature space. Opposed to ST the CTMD equations of motion are fully deterministic and feature a conserved quantity that can be used to validate the simulation. Three variants of CTMD are discussed and compared by means of a simple test system. The implementation features of the most stable and simplest variant CTMD-[Formula: see text] in the program package Iphigenie are described. Two applications - alanine dipeptide (Ac-Ala-NHMe) in explicit water and octa-alanine (Ac-(Ala)8-NHMe) simulated in a dielectric continuum - demonstrate the functionality of CTMD-[Formula: see text]. Furthermore, they serve to evaluate its sampling efficiency. Here, CTMD-[Formula: see text] outperforms ST by 35% and replica exchange even by 75%. PMID:26760910

  19. Winter Weather Checklists

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Weather Information on Specific Types of Emergencies Winter Weather Checklists Language: English Español (Spanish) Recommend on Facebook ...

  20. Winter Weather: Indoor Safety

    ... Health Matters What's New Preparation & Planning Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ... Outdoor Safety Winter PSAs and Podcasts Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis ...

  1. Winter Bottom Trawl Survey

    National Oceanic and Atmospheric Administration, Department of Commerce — The standardized NEFSC Winter Bottom Trawl Survey was initiated in 1992 and covered offshore areas from the Mid-Atlantic to Georges Bank. Inshore strata were...

  2. Soil quality indicators of a mature alley-cropping agroforestry system in temperate North America

    Although agroforestry practices are believed to improve soil quality, reports on long-term effects of alley cropping on soils within agroforestry in the temperate zone are limited. The objective of this study was to examine effects of management, landscape, and soil depth of an established agrofores...

  3. Temper brittleness of structural steel bainite

    Kinetics of reversible temper brittleness of chromium-nickel-molybdenum steel with bainite structure was investigated by constructing isothermal diagrams. It is shown that brittle fracture resistance in nonembrittled state embrittlement rate and degree are sufficiently lower, as compared to martensite structure. Peculiarities of effect of molybdenum and strength level of tempered structure on embrittlement characteristics were studied, as well as peculiarities of fracture and segregation processes in the case of temper brittleness of bainite

  4. Parallel Tempering: Theory, Applications, and New Perspectives

    Earl, David J.; Deem, Michael W

    2005-01-01

    We review the history of the parallel tempering simulation method. From its origins in data analysis, the parallel tempering method has become a standard workhorse of physiochemical simulations. We discuss the theory behind the method and its various generalizations. We mention a selected set of the many applications that have become possible with the introduction of parallel tempering and we suggest several promising avenues for future research.

  5. Cyclic voles and shrews and non-cyclic mice in a marginal grassland within European temperate forest.

    Zub, K; Jędrzejewska, B; Jędrzejewski, W; Bartoń, K A

    2012-07-01

    Cyclic population dynamics of small mammals are not restricted to the boreal and arctic zones of Eurasia and North America, but long-term data series from lower latitudes are still less common. We demonstrated here the presence of periodic oscillations in small mammal populations in eastern Poland using 22-year (1986-2007) trapping data from marginal meadow and river valley grasslands located in the extensive temperate woodland of Białowieża Primeval Forest. The two most common species inhabiting meadows and river valleys, root vole Microtus oeconomus and common shrew Sorex araneus, exhibited synchronous periodic changes, characterised by a 3-year time lag as indicated by an autocorrelation function. Moreover, the cycles of these two species were synchronous within both habitats. Population dynamics of the striped field mouse Apodemus agrarius was not cyclic. However, this species regularly reached maximum density 1 year before the synchronized peak of root voles and common shrews, which may suggest the existence of interspecific competition. Dynamics of all three species was dominated by direct density-dependent process, whereas delayed density dependent feedback was significant only in the root vole and common shrew. Climatic factors acting in winter and spring (affecting mainly survival and initial reproduction rates) were more important than those acting in summer and autumn and affected significantly only the common shrew. High temperatures in winter and spring had positive effects on autumn-to-autumn changes in abundance of this species, whereas deep snow in combination with high rainfall in spring negatively affected population increase rates in common shrew. PMID:22707756

  6. Cave visitation by temperate zone bats: effects of climatic factors

    Berková, Hana; Zukal, Jan

    2010-01-01

    Roč. 280, č. 4 (2010), s. 387-395. ISSN 0952-8369 R&D Projects: GA ČR GA206/01/1555; GA MŠk LC06073 Institutional research plan: CEZ:AV0Z60930519 Keywords : automatic registration * bats * flight activity * hibernaculum * seasonal changes Subject RIV: EG - Zoology Impact factor: 1.787, year: 2010

  7. Laser beam welding tempered 300M ultrahigh mechanical strength steel

    Sheila Medeiros de, Carvalho; Milton Srgio Fernandes de, Lima.

    2012-03-01

    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 400C. 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.

  8. Numerical investigation of a novel connection in tempered glass using holes drilled after tempering

    Nielsen, Jens Henrik

    This paper is a continuation of a previous paper [Nielsen, 2012] where the influ-ence on the temper stresses by drilling into tempered glass was investigated. In [Nielsen, 2012] it was shown that partly drilled holes in tempered glass would lead to higher compressive resid-ual hoop stresses at the...

  9. Mechanism of Secondary Hardening in Rapid Tempering of Dual-Phase Steel

    Saha, Dulal Chandra; Nayak, Sashank S.; Biro, Elliot; Gerlich, Adrian P.; Zhou, Y.

    2014-12-01

    Dual-phase steel with ferrite-martensite-bainite microstructure exhibited secondary hardening in the subcritical heat affected zone during fiber laser welding. Rapid isothermal tempering conducted in a Gleeble simulator also indicated occurrence of secondary hardening at 773 K (500 C), as confirmed by plotting the tempered hardness against the Holloman-Jaffe parameter. Isothermally tempered specimens were characterized by analytic transmission electron microscopy and high-angle annular dark-field imaging. The cementite (Fe3C) and TiC located in the bainite phase of DP steel decomposed upon rapid tempering to form needle-shaped Mo2C (aspect ratio ranging from 10 to 25) and plate-shaped M4C3 carbides giving rise to secondary hardening. Precipitation of these thermodynamically stable and coherent carbides promoted the hardening phenomenon. However, complex carbides were only seen in the tempered bainite and were not detected in the tempered martensite. The martensite phase decomposed into ferrite and spherical Fe3C, and interlath-retained austenite decomposed into ferrite and elongated carbide.

  10. Root development of fodder radish and winter wheat before winter in relation to uptake of nitrogen

    Wahlström, Ellen Margrethe; Hansen, Elly Møller; Mandel, A.; Garbout, Amin; Kristensen, Hanne Lakkenborg; Munkholm, Lars Juhl

    2015-01-01

    depleting the soil of mineral nitrogen (Nmin) before winter. A secondary aim was to study the agreement between three different root measuring methods: root wash (RW), core break (CB) and minirhizotron (MR). The third aim of the was to correlate the N uptake of FR and WW with RLD. An experiment was made to...... see if and how root growth was affected by the minirhizotron tube. The experiments were conducted on a Danish sandy loam soil. From September to November the amount of soil Nmin decreased from 49kgNha-1 to 14kgNha-1 under FR and increased from 28kgNha-1 to 44kgNha-1 under WW. A test of correlations......The nitrate (N) present in soil at the end of autumn is prone to leach during winter and spring in temperate climates if not taken up by plants. In Denmark catch crops are used as a regulatory tool to reduce N leaching and therefore a shift from winter cereals to spring cereals with catch crops has...

  11. On choice of tempered steels

    For the purpose of developing a graphical method for choosing structural steels, a change in the propagation work of a crack and in the critical temperature of brittleness of 40, 40Kh, 40KhN, and 40KhNM steels, was examined depending on the hardness after hardening and tempering. A diagram enabling to choose the grade of steel for making an article of known dimensions according to the preset values of its mechanical properties has been plotted. The developed selection scheme takes into account the hardenability of steels and the influence of the hardness after thermal treatment on the cold-shortness of steel

  12. Rates of nocturnal transpiration in two evergreen temperate woodland species with differing water-use strategies.

    Zeppel, Melanie; Tissue, David; Taylor, Daniel; Macinnis-Ng, Catriona; Eamus, Derek

    2010-08-01

    Nocturnal fluxes may be a significant factor in the annual water budget of forested ecosystems. Here, we assessed sap flow in two co-occurring evergreen species (Eucalyptus parramattensis and Angophora bakeri) in a temperate woodland for 2 years in order to quantify the magnitude of seasonal nocturnal sap flow (E(n)) under different environmental conditions. The two species showed different diurnal water relations, demonstrated by different diurnal curves of stomatal conductance, sap flow and leaf water potential. The relative influence of several microclimatic variables, including wind speed (U), vapour pressure deficit (D), the product of U and D (UD) and soil moisture content, were quantified. D exerted the strongest influence on E(n) (r² = 0.59-0.86), soil moisture content influenced E(n) when D was constant, but U and UD did not generally influence E(n). In both species, cuticular conductance (G(c)) was a small proportion of total leaf conductance (G(s)) and was not a major pathway for E(n). We found that E(n) was primarily a function of transpiration from the canopy rather than refilling of stem storage, with canopy transpiration accounting for 50-70% of nocturnal flows. Mean E(n) was 6-8% of the 24-h flux across seasons (spring, summer and winter), but was up to 19% of the 24-h flux on some days in both species. Despite different daytime strategies in water use of the two species, both species demonstrated low night-time water loss, suggesting similar controls on water loss at night. In order to account for the impact of E(n) on pre-dawn leaf water potential arising from the influence of disequilibria between root zone and leaf water potential, we also developed a simple model to more accurately predict soil water potential (ψ(s)). PMID:20566582

  13. Preventive maintenance technique by temper bead welding for reactor vessel

    Pressurized Water Reactor (PWR) plant has some dissimilar weld joint between main components which are made of Low Alloy Steel and piping which is made of Stainless Steel. Previous plants' dissimilar weld joints are made of Alloy 600 which is low resistance to Primary Water Stress Corrosion Cracking (PWSCC). It is reported that PWSCC is occurred in some plants. The preventive maintenance technique against PWSCC is needed immediately. One solution is the improvement of the material, for example, the inner surface of Alloy 600 is replaced by welding Alloy 690 which is high resistance to PWSCC. Generally, Heat Affected Zone (HAZ) of low alloy steel after welding is required Post Weld Heat Treatment (PWHT), but it is so hard that this operation has to be accomplished in site. So it is necessary to attempt the improvement of HAZ by temper bead welding which isn't needed PWHT. Temper bead welding is that HAZ of 1st weld layer is appropriately covered with heat of after 2nd weld layer, then the mechanical performance of HAZ is improved as well as PWHT. Conventional temper bead welding is required pre-heat and post-heat treatment. However it is impossible to set up the heater due to environment around the dissimilar weld joint in some plants, the development of ambient temperature temper bead welding technique which isn't needed pre-heat and post-heat treatment is expected. It is confirmed that the mechanical performance and the material texture are improved by setting the appropriate welding condition with many welding test pieces. Then, the preventive maintenances called INLAY method are completed in some actual plants. (author)

  14. Global warming reduces plant reproductive output for temperate multi-inflorescence species on the Tibetan plateau.

    Liu, Yinzhan; Mu, Junpeng; Niklas, Karl J; Li, Guoyong; Sun, Shucun

    2012-07-01

    Temperature is projected to increase more during the winter than during the summer in cold regions. The effects of winter warming on reproductive effort have not been examined for temperate plant species. Here, we report the results of experimentally induced seasonal winter warming (0.4 and 2.4C increases in growing and nongrowing seasons, respectively, using warmed and ambient open-top chambers in a Tibetan Plateau alpine meadow) for nine indeterminate-growing species producing multiple (single-flowered or multi-flowered) inflorescences and three determinate-growing species producing single inflorescences after a 3-yr period of warming. Warming reduced significantly flower number and seed production per plant for all nine multi-inflorescence species, but not for the three single-inflorescence species. Warming had an insignificant effect on the fruit to flower number ratio, seed size and seed number per fruit among species. The reduction in seed production was largely attributable to the decline in flower number per plant. The flowering onset time was unaffected for nine of the 12 species. Therefore, the decline in flower production and seed production in response to winter warming probably reflects a physiological response (e.g. metabolic changes associated with flower production). Collectively, the data indicate that global warming may reduce flower and seed production for temperate herbaceous species and will probably have a differential effect on single- vs multi-inflorescence species. PMID:22591333

  15. 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

    Javier Alcocer

    2008-08-01

    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.

  16. Microstructure and Mechanical Properties of Laser Clad and Post-cladding Tempered AISI H13 Tool Steel

    Telasang, Gururaj; Dutta Majumdar, Jyotsna; Wasekar, Nitin; Padmanabham, G.; Manna, Indranil

    2015-05-01

    This study reports a detailed investigation of the microstructure and mechanical properties (wear resistance and tensile strength) of hardened and tempered AISI H13 tool steel substrate following laser cladding with AISI H13 tool steel powder in as-clad and after post-cladding conventional bulk isothermal tempering [at 823 K (550 C) for 2 hours] heat treatment. Laser cladding was carried out on AISI H13 tool steel substrate using a 6 kW continuous wave diode laser coupled with fiber delivering an energy density of 133 J/mm2 and equipped with a co-axial powder feeding nozzle capable of feeding powder at the rate of 13.3 10-3 g/mm2. Laser clad zone comprises martensite, retained austenite, and carbides, and measures an average hardness of 600 to 650 VHN. Subsequent isothermal tempering converted the microstructure into one with tempered martensite and uniform dispersion of carbides with a hardness of 550 to 650 VHN. Interestingly, laser cladding introduced residual compressive stress of 670 15 MPa, which reduces to 580 20 MPa following isothermal tempering. Micro-tensile testing with specimens machined from the clad zone across or transverse to cladding direction showed high strength but failure in brittle mode. On the other hand, similar testing with samples sectioned from the clad zone parallel or longitudinal to the direction of laser cladding prior to and after post-cladding tempering recorded lower strength but ductile failure with 4.7 and 8 pct elongation, respectively. Wear resistance of the laser surface clad and post-cladding tempered samples (evaluated by fretting wear testing) registered superior performance as compared to that of conventional hardened and tempered AISI H13 tool steel.

  17. 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

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

    2011-01-01

    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...

  18. WINTER, Interactive WIMS Input Preparation

    1 - Description of program or function: The WINTER code permits interactive preparation of different WIMS input data. 2 - Restrictions on the complexity of the problem: There are a few WIMS input keywords not included in WINTER, (see the User's Manual)

  19. Editorial - The winter Atomiades

    Staff Association

    2011-01-01

    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...

  20. Geometry of Winter model

    Aglietti, U. G.; Santini, P. M.

    2015-06-01

    By constructing the Riemann surface controlling the resonance structure of Winter model, we determine the limitations of perturbation theory. We then derive explicit non-perturbative results for various observables in the weak-coupling regime, in which the model has an infinite tower of long-lived resonant states. The problem of constructing proper initial wavefunctions coupled to single excitations of the model is also treated within perturbative and non-perturbative methods.

  1. Winter maintenance and cycleways

    Bergström, Anna

    2002-01-01

    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...

  2. Developing tempering parameter for ductile cast iron

    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

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

    Mihai, Bogdan; Savulescu, Ionut

    2014-05-01

    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.

  4. Prediction of toughness in HAZ produced by temper bead welding of consistent layer technique

    Temper bead welding (TBW) is one effective repair welding method for the large-scale nuclear power plants instead of post weld heat treatment (PWHT). Consistent Layer (CSL) technique is the theoretically most authoritative method among the five temper bead welding techniques. For TBW, toughness is the key criteria to evaluate the tempering effect. A neural network-based method for toughness prediction in heat affected zone (HAZ) of low-alloy steel has been investigated to evaluate the tempering effect in TBW. On the basis of experimentally obtained database, the new toughness prediction system was constructed by using Radial basis function-neural network. With it, the toughness distribution in HAZ of TBW was calculated based on the thermal cycles numerically obtained by finite element method (FEM). The predicted toughness was in good accordance with the experimental results. It follows that our new prediction system is effective for estimating the tempering effect during TBW and hence enables us to assess the effectiveness of TBW before the actual repair welding. (author)

  5. NEW Fe-C-Mn-Si-Cr BEARING ALLOY: TEMPERING CURVES AND TEMPERED MARTENSITE EMBRITTLEMENT

    Jos Benedito Marcomini; Hlio Goldenstein

    2012-01-01

    SAE 52100 steel is not only used as a rolled raw material for bearing manufacturing but for building some rolling devices as well, such as guide rollers and straightener rollers. The purpose of this work is the characterization of a Fe-C-Mn-Si-Cr bearing alloy (SAE 52100 steel, modified with 1.74% Si) by plotting the variation of quenched and tempered hardness curve (tempering curve) and tempered martensite embrittlement susceptibility. The present application is based on the same...

  6. Winter Frost and Fog

    2005-01-01

    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

  7. Optimized parallel tempering simulations of proteins

    Trebst, S.; Troyer, M; Hansmann, U. H. E.

    2006-01-01

    We apply a recently developed adaptive algorithm that systematically improves the efficiency of parallel tempering or replica exchange methods in the numerical simulation of small proteins. Feedback iterations allow us to identify an optimal set of temperatures/replicas which are found to concentrate at the bottlenecks of the simulations. A measure of convergence for the equilibration of the parallel tempering algorithm is discussed. We test our algorithm by simulating the 36-residue villin h...

  8. Results From The UKQCD Parallel Tempering Project

    Joo, Balint; collaboration, UKQCD

    1998-01-01

    We present results from our study of the Parallel Tempering algorithm. We examine the swapping acceptance rate of a twin subensemble PT system. We use action matching technology in an attempt to maximise the swap acceptance rate. We model the autocorrelation times within Parallel Tempering ensembles in terms of autocorrelation times from Hybrid Monte Carlo. We present estimates for the autocorrelation times of the plaquette operator.

  9. Comparison of sampling efficiency between simulated tempering and replica exchange

    Zhang, Cheng; Ma, Jianpeng

    2008-01-01

    We compared the sampling efficiency of simulated tempering and replica exchange. Our results indicate that simulated tempering is superior to replica exchange if the parameters for temperature transition in simulated tempering are adjusted to be proportional to the partition function. It is shown that, in simulated tempering, the rate of traversing energy space of different temperatures is much higher than that in replica exchange, especially in the case of low tempering frequency and∕or larg...

  10. Vertical distribution of mesozooplankton in the central and eastern Arabian Sea during the winter monsoons

    Padmavati, G.; Haridas, P.; Nair, K.K.C.; Gopalakrishnan, T.C.; Shiney, P.; Madhupratap, M.

    The vertical distribution of mesozooplankton in the central and eastern Arabian Sea was investigated during the winter monsoon in 1995. Samples were analysed from discrete depth zones defined according to oxygen and temperature profiles of the water...

  11. Decontamination and winter conditions

    The report deals with two decontamonation experiments under winter conditions. A snow-covered parking lot was contaminated, and the snow was subsequently removed using standard snow-moving equipment. The snow left behind was collected and the content of contaminant was determined. A non-radioactive contaminant was used. A decontamination factor exceeding 100 was obtained. Although the eksperimental conditions were close to ideal, it is reason to believe that extremely efficient removal of deposited materials on a snow surface is achivable. In another investigation, run-off from agricultural surface, contaminated while covered with snow, was measured A lycimeter was used in this experiment. A stable layer of ice and snow was allowed to form before contamination. The run-off water was collected at each thaw period until all snow and ice was gone. Cs-134 was used as contaminant. Roughly 30% of the Cs-134 with which the area was contaminated ran off with the melt water. Following a reactor accident situation, this would have given a corresponding reduction in the long term doses. Both of these experiments show that consequence calculation assumptions, as they are currently applied to large accident assessment, tend to overestimate the consequences resulting from accidents taking place under winter conditions

  12. Winter School Les Houches

    Lannoo, Michel; Bastard, Gérald; Voos, Michel; Boccara, Nino

    1986-01-01

    The Winter School held in Les Houches on March 12-21, 1985 was devoted to Semiconductor Heterojunctions and Superlattices, a topic which is recognized as being now one of the most interesting and active fields in semiconductor physics. In fact, following the pioneering work of Esaki and Tsu in 1970, the study of these two-dimensional semiconductor heterostructures has developed rapidly, both from the point of view of basic physics and of applications. For instance, modulation-doped heterojunctions are nowadays currently used to investigate the quantum Hall effect and to make very fast transistors. This book contains the lectures presented at this Winter School, showing in particular that many aspects of semiconductor heterojunctions and super­ lattices were treated, extending from the fabrication of these two-dimensional systems to their basic properties and applications in micro-and opto-electron­ ics. Among the subjects which were covered, one can quote as examples: molecular beam epitaxy and metallorgani...

  13. Temperate origins of long-distance seasonal migration in New World songbirds.

    Winger, Benjamin M; Barker, F Keith; Ree, Richard H

    2014-08-19

    Migratory species exhibit seasonal variation in their geographic ranges, often inhabiting geographically and ecologically distinct breeding and nonbreeding areas. The complicated geography of seasonal migration has long posed a challenge for inferring the geographic origins of migratory species as well as evolutionary sequences of change in migratory behavior. To address this challenge, we developed a phylogenetic model of the joint evolution of breeding and nonbreeding (winter) ranges and applied it to the inference of biogeographic history in the emberizoid passerine birds. We found that seasonal migration between breeding ranges in North America and winter ranges in the Neotropics evolved primarily via shifts of winter ranges toward the tropics from ancestral ranges in North America. This result contrasts with a dominant paradigm that hypothesized migration evolving out of the tropics via shifts of the breeding ranges. We also show that major lineages of tropical, sedentary emberizoids are derived from northern, migratory ancestors. In these lineages, the winter ranges served as a biogeographic conduit for temperate-to-tropical colonization: winter-range shifts toward the tropics during the evolution of long-distance migration often preceded southward shifts of breeding ranges, the loss of migration, and in situ tropical diversification. Meanwhile, the evolution of long-distance migration enabled the persistence of old lineages in North America. These results illuminate how the evolution of seasonal migration has contributed to greater niche conservatism among tropical members of this diverse avian radiation. PMID:25092321

  14. First Temperate Exoplanet Sized Up

    2010-03-01

    Combining observations from the CoRoT satellite and the ESO HARPS instrument, astronomers have discovered the first "normal" exoplanet that can be studied in great detail. Designated Corot-9b, the planet regularly passes in front of a star similar to the Sun located 1500 light-years away from Earth towards the constellation of Serpens (the Snake). "This is a normal, temperate exoplanet just like dozens we already know, but this is the first whose properties we can study in depth," says Claire Moutou, who is part of the international team of 60 astronomers that made the discovery. "It is bound to become a Rosetta stone in exoplanet research." "Corot-9b is the first exoplanet that really does resemble planets in our solar system," adds lead author Hans Deeg. "It has the size of Jupiter and an orbit similar to that of Mercury." "Like our own giant planets, Jupiter and Saturn, the planet is mostly made of hydrogen and helium," says team member Tristan Guillot, "and it may contain up to 20 Earth masses of other elements, including water and rock at high temperatures and pressures." Corot-9b passes in front of its host star every 95 days, as seen from Earth [1]. This "transit" lasts for about 8 hours, and provides astronomers with much additional information on the planet. This is fortunate as the gas giant shares many features with the majority of exoplanets discovered so far [2]. "Our analysis has provided more information on Corot-9b than for other exoplanets of the same type," says co-author Didier Queloz. "It may open up a new field of research to understand the atmospheres of moderate- and low-temperature planets, and in particular a completely new window in our understanding of low-temperature chemistry." More than 400 exoplanets have been discovered so far, 70 of them through the transit method. Corot-9b is special in that its distance from its host star is about ten times larger than that of any planet previously discovered by this method. And unlike all such exoplanets, the planet has a temperate climate. The temperature of its gaseous surface is expected to be between 160 degrees and minus twenty degrees Celsius, with minimal variations between day and night. The exact value depends on the possible presence of a layer of highly reflective clouds. The CoRoT satellite, operated by the French space agency CNES [3], identified the planet after 145 days of observations during the summer of 2008. Observations with the very successful ESO exoplanet hunter - the HARPS instrument attached to the 3.6-metre ESO telescope at La Silla in Chile - allowed the astronomers to measure its mass, confirming that Corot-9b is indeed an exoplanet, with a mass about 80% the mass of Jupiter. This finding is being published in this week's edition of the journal Nature. Notes [1] A planetary transit occurs when a celestial body passes in front of its host star and blocks some of the star's light. This type of eclipse causes changes in the apparent brightness of the star and enables the planet's diameter to be measured. Combined with radial velocity measurements made by the HARPS spectrograph, it is also possible to deduce the mass and, hence, the density of the planet. It is this combination that allows astronomers to study this object in great detail. The fact that it is transiting - but nevertheless not so close to its star to be a "hot Jupiter" - is what makes this object uniquely well suited for further studies. [2] Temperate gas giants are, so far, the largest known group of exoplanets discovered. [3] The CoRoT (Convection, Rotation and Transits) space telescope was constructed by CNES, with contributions from Austria, Germany, Spain, Belgium, Brazil and the European Space Agency (ESA). It was specifically designed to detect transiting exoplanets and carry out seismological studies of stars. Its results are supplemented by observations with several ground-based telescopes, among them the IAC-80 (Teide Observatory), the Canada Fra

  15. Winter weather scorecard

    Last fall's 3-month winter weather prediction by National Weather Service (NWS) forecasters was not terrific, but it was not too far off the mark, either. A comparison of the predicted temperatures and precipitation (Eos, December 25, 1984, p. 1241) to the observed conditions (see Figures 1 and 2) during the months of December, January, and February shows that the forecasters were generally correct where they were most confident in their predictions.According to Donald Gilman, chief of the Predictions Branch at NWS's National Climate Analysis Center, the overall temperature forecast was probably better than that for precipitation. “The temperature forecast was pretty good in the West,” said Gilman. “East of the Mississippi, however, was a mixed picture.”

  16. Winter fuels report

    1995-02-17

    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.

  17. Spirit Scans Winter Haven

    2006-01-01

    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.

  18. Winter fuels report

    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

  19. Winter fuels report

    1995-02-03

    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 and 30-Day outlook for temperature and precipitation and US total heating degree-days by city.

  20. Winter fuels report

    1990-11-29

    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.

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

    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)

  2. Plasmodium vivax populations revisited: mitochondrial genomes of temperate strains in Asia suggest ancient population expansion

    Miao Miao

    2012-02-01

    Full Text Available Abstract Background Plasmodium vivax is the most widely distributed human malaria parasite outside of Africa, and its range extends well into the temperate zones. Previous studies provided evidence for vivax population differentiation, but temperate vivax parasites were not well represented in these analyses. Here we address this deficit by using complete mitochondrial (mt genome sequences to elucidate the broad genetic diversity and population structure of P. vivax from temperate regions in East and Southeast Asia. Results From the complete mtDNA sequences of 99 clinical samples collected in China, Myanmar and Korea, a total of 30 different haplotypes were identified from 26 polymorphic sites. Significant differentiation between different East and Southeast Asian parasite populations was observed except for the comparison between populations from Korea and southern China. Haplotype patterns and structure diversity analysis showed coexistence of two different groups in East Asia, which were genetically related to the Southeast Asian population and Myanmar population, respectively. The demographic history of P. vivax, examined using neutrality tests and mismatch distribution analyses, revealed population expansion events across the entire P. vivax range and the Myanmar population. Bayesian skyline analysis further supported the occurrence of ancient P. vivax population expansion. Conclusions This study provided further resolution of the population structure and evolution of P. vivax, especially in temperate/warm-temperate endemic areas of Asia. The results revealed divergence of the P. vivax populations in temperate regions of China and Korea from other populations. Multiple analyses confirmed ancient population expansion of this parasite. The extensive genetic diversity of the P. vivax populations is consistent with phenotypic plasticity of the parasites, which has implications for malaria control.

  3. Seedling growth and biomass allocation in relation to leaf habit and shade tolerance among 10 temperate tree species.

    Modrzyński, Jerzy; Chmura, Daniel J; Tjoelker, Mark G

    2015-08-01

    Initial growth of germinated seeds is an important life history stage, critical for establishment and succession in forests. Important questions remain regarding the differences among species in early growth potential arising from shade tolerance. In addition, the role of leaf habit in shaping relationships underlying shade tolerance-related differences in seedling growth remains unresolved. In this study we examined variation in morphological and physiological traits among seedlings of 10 forest tree species of the European temperate zone varying in shade tolerance and leaf habit (broadleaved winter-deciduous species vs needle-leaved conifers) during a 10-week period. Seeds were germinated and grown in a controlled environment simulating an intermediate forest understory light environment to resolve species differences in initial growth and biomass allocation. In the high-resource experimental conditions during the study, seedlings increased biomass allocation to roots at the cost of leaf biomass independent of shade tolerance and leaf habit. Strong correlations between relative growth rate (RGR), net assimilation rate (NAR), leaf area ratio (LAR), specific leaf area (SLA) and leaf mass fraction (LMF) indicate that physiology and biomass allocation were equally important determinants of RGR as plant structure and leaf morphology among these species. Our findings highlight the importance of seed mass- and seed size-related root morphology (specific root length-SRL) for shade tolerance during early ontogeny. Leaf and plant morphology (SLA, LAR) were more successful in explaining variation among species due to leaf habit than shade tolerance. In both broadleaves and conifers, shade-tolerant species had lower SRL and greater allocation of biomass to stems (stem mass fraction). Light-seeded shade-intolerant species with greater SRL had greater RGR in both leaf habit groups. However, the greatest plant mass was accumulated in the group of heavy-seeded shade-tolerant broadleaves. The results of our study suggest that the combinations of plant attributes enhancing growth under high light vary with shade tolerance, but differ between leaf habit groups. PMID:26116924

  4. Summable families in tempered distribution spaces

    Carfí, David

    2011-01-01

    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 we introduce here is summable with respect to every tempered system of coefficients belonging to a certain normal space of distributions, in the sense of superpositions. The summable families we present in this note are one possible rigorous and simply manageable mathematical model for the infinite families of vector-states appearing in the formulation of the continuous version of the celebrated Principle of Superpositions in Quantum Mechanics.

  5. NEW Fe-C-Mn-Si-Cr BEARING ALLOY: TEMPERING CURVES AND TEMPERED MARTENSITE EMBRITTLEMENT

    Jos Benedito Marcomini

    2012-12-01

    Full Text Available SAE 52100 steel is not only used as a rolled raw material for bearing manufacturing but for building some rolling devices as well, such as guide rollers and straightener rollers. The purpose of this work is the characterization of a Fe-C-Mn-Si-Cr bearing alloy (SAE 52100 steel, modified with 1.74% Si by plotting the variation of quenched and tempered hardness curve (tempering curve and tempered martensite embrittlement susceptibility. The present application is based on the same idea as 300M steel regarding SAE 4340 steel. The effect of silicon on the kinetics of cementite precipitation leads to a rise in temperature of tempered martensite embrittlement. Quench and temper treatments were carried out and impact tests were performed with modified and commercial steels and the results were compared. Microstructure aspects are studied by scanning electron microscopy and x-ray diffraction analysis. The silicon alloyed steel presents great resistance to softening after tempering and no tempered martensite embrittlement.

  6. Raising the temper-μ-spot analysis of temper inclusions in experimental ceramics

    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, μ-spot analysis of temper inclusions was performed at the microbeam particle induced X-ray Emission (μ-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 μ-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)

  7. Effects of seasonal snow on the growing season of temperate vegetation in China.

    Yu, Zhen; Liu, Shirong; Wang, Jingxin; Sun, Pengsen; Liu, Weiguo; Hartley, Damon S

    2013-07-01

    Variations in seasonal snowfall regulate regional and global climatic systems and vegetation growth by changing energy budgets of the lower atmosphere and land surface. We investigated the effects of snow on the start of growing season (SGS) of temperate vegetation in China. Across the entire temperate region in China, the winter snow depth increased at a rate of 0.15 cm yr(-1) (P = 0.07) during the period 1982-1998, and decreased at a rate of 0.36 cm yr(-1) (P = 0.09) during the period 1998-2005. Correspondingly, the SGS advanced at a rate of 0.68 day yr(-1) (P warming trend throughout the entire study period of 1982-2005. Spring air temperature strongly regulated the SGS of both deciduous broad-leaf and coniferous forests, whereas the winter snow had a greater impact on the SGS of grassland and shrubs. Snow depth variation combined with air temperature contributed to the variability in the SGS of grassland and shrubs, as snow acted as an insulator and modulated the underground thermal conditions. In addition, differences were seen between the impacts of winter snow depth and spring snow depth on the SGS; as snow depths increased, the effect associated went from delaying SGS to advancing SGS. The observed thresholds for these effects were snow depths of 6.8 cm (winter) and 4.0 cm (spring). The results of this study suggest that the response of the vegetation's SGS to seasonal snow change may be attributed to the coupling effects of air temperature and snow depth associated with the underground thermal conditions. PMID:23532953

  8. A Transnational Temperance Discourse? William Wells Brown, Creole Civilization, and Temperate Manners

    Carole Lynn Stewart

    2011-03-01

    Full Text Available

    In the nineteenth century, temperance movements provided the occasion for a transnational discourse. These conversations possessed an intensity throughout Britain and the United States. In America temperance often became associated with strongly nationalistic Euro-American forms of identity and internal purity. Nonetheless, African American reformers and abolitionists bound themselves to temperance ideals in forming civil societies that would heal persons and provide communal modes of democratic freedom in the aftermath and recovery from chattel slavery. This paper explores the possibilities of temperance as a transnational discourse by considering its meaning in the life and work of the African American author and activist, William Wells Brown. Brown expressed a creole civilization that employed the stylistics of the trickster as a unique mode of restraint that revealed a peculiar power of passivity that was able to claim efficacy over ones life and community. This meaning of temperance diverges from and dovetails with certain European meanings of civilization that were being forged in the nineteenth century. Brown was in conversation with temperance reformers in America, Britain, and Europe. He imagined the possible meaning of temperance in African, Egyptian, Christian, and Islamic civilizations. He speculated upon the possibility of temperance as a defining characteristic of a transnational civilization and culture that would provide spaces for the expression of democratic freedom. Brown reimagined temperance as a form of corporeal restraint that offered a direct and sacred relation to the land, space, people that appeared in between an ethnic nationalist ethos and the European imperialistic civilization.

  9. 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

    OSVALDO J VIDAL

    2011-01-01

    Full Text Available 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. Classification (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 forests, while the forests in the Pascua basin remain pristine since no human population occurs thereEste 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

  10. Klaus Winter (1930 - 2015)

    2015-01-01

    We learned with great sadness that Klaus Winter passed away on 9 February 2015, after a long illness.   Klaus was born in 1930 in Hamburg, where he obtained his diploma in physics in 1955. From 1955 to 1958 he held a scholarship at the Collège de France, where he received his doctorate in nuclear physics under the guidance of Francis Perrin. Klaus joined CERN in 1958, where he first participated in experiments on π+ and K0 decay properties at the PS, and later became the spokesperson of the CHOV Collaboration at the ISR. Starting in 1976, his work focused on experiments with the SPS neutrino beam. In 1984 he joined Ugo Amaldi to head the CHARM experiment, designed for detailed studies of the neutral current interactions of high-energy neutrinos, which had been discovered in 1973 using the Gargamelle bubble chamber at the PS. The unique feature of the detector was its target calorimeter, which used large Carrara marble plates as an absorber material. From 1984 to 1991, Klau...

  11. Winter fuels report

    1995-01-13

    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.

  12. "Winter is coming"

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

    2013-01-01

    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-...

  13. Winter fuels report

    1990-10-04

    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.

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

    Wyłomańska, Agnieszka

    2012-01-01

    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.

  15. Tempered glass and thermal shock of ceramic materials

    Bunnell, L. Roy

    1992-01-01

    A laboratory experiment is described that shows students the different strengths and fracture toughnesses between tempered and untempered glass. This paper also describes how glass is tempered and the materials science aspects of the process.

  16. Hardness prediction of HAZ in temper bead welding by non-consistent layer technique

    Based on the experimentally obtained hardness database, the neural network-based hardness prediction system of heat affect zone (HAZ) in temper bead welding by Consistent Layer (CSL) technique has been constructed by the authors. However in practical operation, CSL technique is sometimes difficult to perform because of difficulty of the precise heat input controlling, and in such case non-CSL techniques are mainly used in the actual repair process. Therefore in the present study, the neural network-based hardness prediction system of HAZ in temper bead welding by non-CSL techniques has been constructed through thermal cycle simplification, from the view of engineering. The hardness distribution in HAZ with non-CSL techniques was calculated based on the thermal cycles numerically obtained by finite element method. The experimental result has shown that the predicted hardness is in good accordance with the measured ones. It follows that the currently proposed method is effective for estimating the tempering effect during temper bead welding by non-CSL techniques. (author)

  17. Effect of Tempering Condition on Milling Performance and Flour Functionality

    Tempering conditions of wheat grain change the quality of the flour; yet most experimental milling systems use a standard tempering without optimization. The effect of tempering condition on milling performance and flour functionality for three SRW cultivars ('Roane', 'Cyrus', and 'Severn') was tes...

  18. A Facies Model for Temperate Continental Glaciers.

    Ashley, Gail Mowry

    1987-01-01

    Discusses the presence and dynamics of continental glaciers in the domination of the physical processes of erosion and deposition in the mid-latitudes during the Pleistocene period. Describes the use of a sedimentary facies model as a guide to recognizing ancient temperate continental glacial deposits. (TW)

  19. Winter waterfowl survey, southeastern Alaska

    US Fish and Wildlife Service, Department of the Interior Little is known of the total numbers of wintering waterfowl within the north pacific coastal region. The random stratified plot sampling methods used in 1980, as...

  20. Development of temper-bead technique applied to dissimilar welded joints of nuclear pressure vessels

    When nuclear pressure vessels made of low-alloy steel (P-3 Group 3) need repair or modification, technical standards for welding of electrical structures should be applied, and then postweld heat treatment (PWHT) should be done. However, cases in which PWHT is impractical are theoretically possible due to a variety of restrictions. To deal with such a problem, there is a regulation for repair weld technique, without PWHT, in accordance with ASME B and PV Code. This method is called temper-bead technique, which gives the weldments sufficient toughness by tempering the hardened zone of the heat-affected zone on the first layer of the base metal using the heat of the following weld beads. Because there is no regulation in Japan covering this method, a procedure is required to perform it under a special license, after a verification test has been passed. An attempt has been made to develop a method, on the supposition that the temper-bead technique is adopted for replacement of what is called dissimilar welded joints, so that a nickel base alloy is buildup welded at the tip of the nozzle of the low-alloy steel pressure vessel, and a stainless steel pipe is butt welded

  1. Reproductive arrest and stress resistance in winter-acclimated Drosophila suzukii.

    Toxopeus, Jantina; Jakobs, Ruth; Ferguson, Laura V; Gariepy, Tara D; Sinclair, Brent J

    2016-06-01

    Overwintering insects must survive the multiple-stress environment of winter, which includes low temperatures, reduced food and water availability, and cold-active pathogens. Many insects overwinter in diapause, a developmental arrest associated with high stress tolerance. Drosophila suzukii (Diptera: Drosophilidae), spotted wing drosophila, is an invasive agricultural pest worldwide. Its ability to overwinter and therefore establish in temperate regions could have severe implications for fruit crop industries. We demonstrate here that laboratory populations of Canadian D. suzukii larvae reared under short-day, low temperature, conditions develop into dark 'winter morph' adults similar to those reported globally from field captures, and observed by us in southern Ontario, Canada. These winter-acclimated adults have delayed reproductive maturity, enhanced cold tolerance, and can remain active at low temperatures, although they do not have the increased desiccation tolerance or survival of fungal pathogen challenges that might be expected from a more heavily melanised cuticle. Winter-acclimated female D. suzukii have underdeveloped ovaries and altered transcript levels of several genes associated with reproduction and stress. While superficially indicative of reproductive diapause, the delayed reproductive maturity of winter-acclimated D. suzukii appears to be temperature-dependent, not regulated by photoperiod, and is thus unlikely to be 'true' diapause. The traits of this 'winter morph', however, likely facilitate overwintering in southern Canada, and have probably contributed to the global success of this fly as an invasive species. PMID:27039032

  2. Marine Biodiversity in Temperate Western Australia: Multi-Taxon Surveys of Minden and Roe Reefs

    Zoe Richards

    2016-03-01

    Full Text Available A growing body of evidence indicates that temperate marine ecosystems are being tropicalised due to the poleward extension of tropical species. Such climate mediated changes in species distribution patterns have the potential to profoundly alter temperate communities, as this advance can serve to push temperate taxa, many of which are southern Australian endemics, southward. These changes can lead to cascading effects for the biodiversity and function of coastal ecosystems, including contraction of ranges/habitats of sensitive cool water species. Hence there is growing concern for the future of Australia’s temperate marine biodiversity. Here we examine the diversity and abundance of marine flora and fauna at two reefs near Perth’s metropolitan area—Minden Reef and Roe Reef. We report the presence of 427 species of marine flora and fauna from eight taxon groups occurring in the Perth metropolitan area; at least three species of which appear to be new to science. Our data also extends the known range of 15 species, and in numerous instances, thousands of kilometres south from the Kimberley or Pilbara and verifies that tropicalisation of reef communities in the Perth metropolitan area is occurring. We report the presence of 24 species endemic to south-west Australia that may be at risk of range contractions with continued ocean warming. The results of these surveys add to our knowledge of local nearshore marine environments in the Perth metropolitan area and support the growing body of evidence that indicates a diverse and regionally significant marine fauna occurs in temperate Western Australia. Regular, repeated survey work across seasons is important in order to thoroughly document the status of marine biodiversity in this significant transition zone.

  3. What are the effects of agricultural management on soil organic carbon in boreo-temperate systems?

    Haddaway, Neal R.; Hedlund, Katarina; Jackson, Louise E.; Kätterer, Thomas; Lugato, Emanuele; Thomsen, Ingrid Kaag; Jørgensen, Helene Bracht; Söderström, Bo

    2015-01-01

    Background Soils contain the largest stock of organic carbon (C) in terrestrial ecosystems and changes in soil C stocks may significantly affect atmospheric CO2. A significant part of soil C is present in cultivated soils that occupy about 35 % of the global land surface. Agricultural intensifica......Background Soils contain the largest stock of organic carbon (C) in terrestrial ecosystems and changes in soil C stocks may significantly affect atmospheric CO2. A significant part of soil C is present in cultivated soils that occupy about 35 % of the global land surface. Agricultural...... management on SOC in arable systems of the warm temperate and snow climate zones (subset of temperate and continental climates: Köppen–Geiger Classification)....

  4. Heading for Next Winter Haven

    2007-01-01

    Approaching its 47th month of a Mars surface mission originally planned to last three months, NASA's Spirit rover was also approaching the northern edge of a low plateau called 'Home Plate.' The rover's operators selected an area with north-facing slope there as a destination where Spirit would have its best chance of surviving low-solar-energy conditions of oncoming Martian winter. The yellow line on this map of the Home Plate area indicates Spirit's route from early February 2006, entering the mapped area from the north (top), to late November 2007, on the western edge of the bright-toned Home Plate plateau. The map covers an area about 160 meters (525 feet) across from west to east. Labels indicate the area intended for Spirit to spend many months spanning the rover's third Martian winter, the site where it spent about seven months (April to November 2006) spanning its second winter, and the site where it lost use of the drive motor for one of its six wheels. A north-facing slope helps Spirit maximizes electric output from its solar panels during winter months because Spirit is in the southern hemisphere of Mars, so the sun appears only in the northern sky during winter. For the third winter, which will reach its minimum solar-energy days in early June 2008, Spirit faces the challenge of having more dust on its solar panels than it had during its second winter. The base image for this map is a portion of a color image taken on Jan. 9, 2007, by the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter.

  5. Effects of temper condition and corrosion on the fatigue performance of a laser-welded Al-Cu-Mg-Ag (2139) alloy

    The effects of temper condition and corrosion on the fatigue behavior of a laser beam welded Al-Cu-Mg-Ag alloy (2139) have been investigated. Natural aging (T3 temper) and artificial aging (T8 temper) have been applied prior to welding. Corrosion testing has been performed by exposing the welded specimens to a salt spray medium for 720 h. Aging influences the corrosion behavior of laser welds. In the T3 temper, corrosion attack is in the form of pitting in the weld area, while in the T8 temper corrosion is in the form of pitting and intergranular corrosion in the base metal. In the latter case corrosion is attributed to the presence of grain boundary precipitates. Corrosion degrades the fatigue behavior of 2139 welds. The degradation is equal for both the T3 and T8 tempers and for the corrosion exposure selected in this study corresponds to a 52% reduction in fatigue limit. In both cases fatigue crack initiation is associated with corrosion pits, which act as stress raisers. In the T3 temper, the fatigue crack initiation site is at the weld metal/heat affected zone interface, while for the T8 temper the initiation site is at the base metal. Fatigue crack initiation in uncorroded 2139 welds occurs at the weld toe at the root side, the weld reinforcement playing a principal role as stress concentration site. The fatigue crack propagates through the partially melted zone and the weld metal in all cases. The findings in this paper present useful information for the selection of appropriate heat treatment conditions, to facilitate control of the corrosion behavior in aluminium welds, which is of great significance for their fatigue performance.

  6. Schwartz families in tempered distribution spaces

    Carfí, David

    2011-01-01

    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 characterization of summability for Schwartz families) is that the space of linear continuous operators among Schwartz test function spaces is linearly isomorphic with the space of Schwartz families. It should be noticed that this theorem is possible because of the very good properties of Schwartz test function spaces and because of the particular structures of the Schwartz families viewed as generalized matrices; in fact, any family of tempered distribution, regarded as generalized matrix, has one index belonging to a Euclidean space and one belon...

  7. Simulated Tempering: A New Monte Carlo Scheme

    Marinari, Enzo; Parisi, Giorgio

    1992-01-01

    We propose a new global optimization method ({\\em Simulated Tempering}) for simulating effectively a system with a rough free energy landscape (i.e. many coexisting states) at finite non-zero temperature. This method is related to simulated annealing, but here the temperature becomes a dynamic variable, and the system is always kept at equilibrium. We analyze the method on the Random Field Ising Model, and we find a dramatic improvement over conventional Metropolis and cluster methods. We ana...

  8. AGEING AND TEMPERING OF FERROUS MARTENSITES

    Chang, Li; Smith, G.; Olson, G.

    1986-01-01

    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...

  9. Autodeformation of Carburized Steel during Tempering

    Rasa VITKEVIČIENĖ; Regita BENDIKIENĖ

    2013-01-01

    The article analyses the results of autodeformation registered during tempering of carburized steel. Test pieces for the tests were carburized till the different depth in order to examine influence of depth of carburization on the deformation of steel during heat treatment operation. Carburization was performed on the one surface of test pieces seeking to analyze extent of acted normal stresses to autodeformation of steel. Different bending loads were applied for analyzed steel from 5 MPa to ...

  10. Protein Structure Prediction by Tempering Spatial Constraints

    Gront, Dominik; Kolinski, Andrzej; Hansmann, Ulrich H. E.

    2005-01-01

    The probability to predict correctly a protein structure can be enhanced through introduction of spatial constraints - either from NMR experiments or from homologous structures. However, the additional constraints lead often to new local energy minima and worse sampling efficiency in simulations. In this work we present a new parallel tempering variant that alleviates the energy barriers resulting from spatial constraints and therefore yields to an enhanced sampling in structure prediction si...

  11. Robust Parameter Selection for Parallel Tempering

    Hamze, Firas; Dickson, Neil; Karimi, Kamran

    2010-01-01

    This paper describes an algorithm for selecting parameter values (e.g. temperature values) at which to measure equilibrium properties with Parallel Tempering Monte Carlo simulation. Simple approaches to choosing parameter values can lead to poor equilibration of the simulation, especially for Ising spin systems that undergo $1^st$-order phase transitions. However, starting from an initial set of parameter values, the careful, iterative respacing of these values based on results with the previ...

  12. Myxomycetes associated with pipevine, a temperate liana

    Coelho IL; Stephenson SL

    2012-01-01

    Pinevine (Aristolochia macrophylla Lam.), a climbing woody vine native to temperate forests of eastern North America, is morphologically similar to many of the lianas characteristic of moist tropical forests. In August 2010, samples of dead pinevine collected from a study site in the Great Smoky Mountains National Park were used to prepare a series of 50 moist chamber cultures. Thirty-seven of the 50 cultures (74%) yielded evidence (either plasmodia or fruiting bodies) of myxomycetes. Fourtee...

  13. Organic matter stocks in temperate forest soil

    Schning, Ingo

    2006-01-01

    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...

  14. Leaf out phenology in temperate forests

    Caroline A. Polgar

    2013-01-01

    Full Text Available Monitoring phenology, the study of the timing of natural events, is an ancient practice that has experienced renewed relevance for scientific research interest in the wake of awareness of anthropogenic climate change. Spring onset has been occurring significantly earlier in temperate regions worldwide. Leaf out phenology has become particularly well studied is of particular interest because the emergence of leaves in the spring is extremely sensitive to temperature, and the leaf out timing of leaf out in temperate ecosystems marks the onset of the growing season and controls many essential ecosystem processes. This article reviews the current literature concerning the different methods used to study leaf out phenology, the controls on leaf out in temperate woody plants, and the effects of climate change on leaf out phenology. In addition to the traditional method of on-the-ground leaf out monitoring, new methods using remote sensing and dedicated cameras have been developed which allow scientists to track spring onset at a much larger scale than hadpreviously been possible. Further work is needed on how leaf phenology will respond to future climate change, and the implications of this for animals and other species interactions among trophic levels.

  15. Feedback-optimized parallel tempering Monte Carlo

    Katzgraber, Helmut G.; Trebst, Simon; Huse, David A.; Troyer, Matthias

    2006-03-01

    We introduce an algorithm for systematically improving the efficiency of parallel tempering Monte Carlo simulations by optimizing the simulated temperature set. Our approach is closely related to a recently introduced adaptive algorithm that optimizes the simulated statistical ensemble in generalized broad-histogram Monte Carlo simulations. Conventionally, a temperature set is chosen in such a way that the acceptance rates for replica swaps between adjacent temperatures are independent of the temperature and large enough to ensure frequent swaps. In this paper, we show that by choosing the temperatures with a modified version of the optimized ensemble feedback method we can minimize the round-trip times between the lowest and highest temperatures which effectively increases the efficiency of the parallel tempering algorithm. In particular, the density of temperatures in the optimized temperature set increases at the 'bottlenecks' of the simulation, such as phase transitions. In turn, the acceptance rates are now temperature dependent in the optimized temperature ensemble. We illustrate the feedback-optimized parallel tempering algorithm by studying the two-dimensional Ising ferromagnet and the two-dimensional fully frustrated Ising model, and briefly discuss possible feedback schemes for systems that require configurational averages, such as spin glasses.

  16. World temperate fruit production: characteristics and challenges

    Jorge B. Retamales

    2011-10-01

    Full Text Available In the last 30 years world population has increased 70% but per capita global fruit consumption is only 20% higher. Even though tropical and temperate fruit have similar contributions to the 50 kg/person/year of US consumption of fresh fruit, in the last 30 years this has been slightly greater for temperate fruit. Within fruit consumption, the largest expansion has been for organic fruit which increased more than 50% in the 2002-2006 period. The largest expansion of area planted in the 1996-2006 has been for kiwi (29% and blueberries (20%, while apples (-24% and sour cherries (-13% have had the largest reductions. Nearly 50% of the total global volume of fruit is produced by 5 countries: China, USA, Brazil, Italy and Spain. The main producer (China accounts for 23% of the total. While the main exporters are Spain, USA and Italy, the main importers are Germany, Russia and UK. Demands for the industry have evolved towards quality, food safety and traceability. The industry faces higher productions costs (labor, energy, agrichemicals. The retailers are moving towards consolidation while the customers are changing preferences (food for health. In this context there is greater pressure on growers, processors and retailers. Emerging issues are labor supply, climate change, water availability and sustainability. Recent developments in precision agriculture, molecular biology, phenomics, crop modelling and post harvest physiology should increase yields and quality, and reduce costs for temperate fruit production around the world.

  17. Drivers of long-term variability in CO2 net ecosystem exchange in a temperate peatland

    Helfter, C.; Campbell, C.; Dinsmore, K. J.; Drewer, J.; Coyle, M.; Anderson, M.; Skiba, U.; Nemitz, E.; Billett, M. F.; Sutton, M. A.

    2015-03-01

    Land-atmosphere exchange of carbon dioxide (CO2) in peatlands exhibits marked seasonal and inter-annual variability, which subsequently affects the carbon (C) sink strength of catchments across multiple temporal scales. Long-term studies are needed to fully capture the natural variability and therefore identify the key hydrometeorological drivers in the net ecosystem exchange (NEE) of CO2. Since 2002, NEE has been measured continuously by eddy-covariance at Auchencorth Moss, a temperate lowland peatland in central Scotland. Hence this is one of the longest peatland NEE studies to date. For 11 years, the site was a consistent, yet variable, atmospheric CO2 sink ranging from -5.2 to -135.9 g CO2-C m-2 yr-1 (mean of -64.1 ± 33.6 g CO2-C m-2 yr-1). Inter-annual variability in NEE was positively correlated to the length of the growing season. Mean winter air temperature explained 87% of the inter-annual variability in the sink strength of the following summer, indicating an effect of winter climate on local phenology. Ecosystem respiration (Reco) was enhanced by drought, which also depressed gross primary productivity (GPP). The CO2 uptake rate during the growing season was comparable to three other sites with long-term NEE records; however, the emission rate during the dormant season was significantly higher. To summarise, the NEE of the peatland studied is modulated by two dominant factors: - phenology of the plant community, which is driven by winter air temperature and impacts photosynthetic potential and net CO2 uptake during the growing season (colder winters are linked to lower summer NEE), - water table level, which enhanced soil respiration and decreased GPP during dry spells. Although summer dry spells were sporadic during the study period, the positive effects of the current climatic trend towards milder winters on the site's CO2 sink strength could be offset by changes in precipitation patterns especially during the growing season.

  18. Soil respiration under snowpack in a temperate forest in Massachusetts: steady state vs. transient state

    Tang, J.

    2010-12-01

    Soil respiration plays a major role in global carbon cycling. However, the magnitude and process of soil respiration under snowpack is not well understood due to the difficulty in measuring soil respiration in temperate forests under snowpack through the winter. As a result, when the annual cumulative flux of soil respiration is estimated, soil respiration during the winter is either neglected or modeled solely from a temperature function that is derived from the growing season respiration measurement. The traditional chamber method does not work well on snowpack. The eddy covariance method in winter covers total ecosystem respiration that includes both aboveground plant respiration and belowground soil respiration. Here we used a belowground soil CO2 profile system to measure soil respiration under snowpack. The measurement system functioned when the forest floor was covered by snow. Three CO2 sensors were buried vertically, at different depths, in the soil to obtain a CO2 profile. The surface CO2 efflux was calculated based on Fick’s law of diffusion. The snowpack depth was also measured with an automated sonic ranging sensor. Under the steady state, the snowpack did not physically change the soil CO2 efflux, but it increased soil temperature and thus indirectly increased soil CO2 efflux. During the transient period (snowfall or melting), the snowpack changed soil CO2 efflux. The temperature sensitivity, Q10, was higher in the low temperature range than in the high temperature range in winter. Our results suggest that winter soil respiration is more complicated than non-snow covered seasons and should not be neglected in estimating the annual carbon budget.

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

    Zbigniew Pruszak

    2005-09-01

    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.

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

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

    1991-08-20

    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.

  1. Physiological basis of seasonal trend in leaf photosynthesis of five evergreen broad-leaved species in a temperate deciduous forest.

    Miyazawa, Yoshiyuki; Kikuzawa, Kihachiro

    2006-02-01

    The physiological basis of photosynthesis during winter was investigated in saplings of five evergreen broad-leaved species (Camellia japonica L., Cleyera japonica Thunb., Photinia glabra (Thunb.) Maxim., Castanopsis cuspidata (Thunb.) Schottky and Quercus glauca Thunb.) co-occurring under deciduous canopy trees in a temperate forest. We focused on temperature dependence of photosynthetic rate and capacity as important physiological parameters that determine light-saturated rates of net photosynthesis at low temperatures during winter. Under controlled temperature conditions, maximum rates of ribulose bisphosphate carboxylation and electron transport (Vcmax) and Jmax, respectively) increased exponentially with increasing leaf temperature. The temperature dependence of photosynthetic rate did not differ among species. In the field, photosynthetic capacity, determined as Vcmax and Jmax at a common temperature of 25 degrees C (Vcmax(25) and Jmax(25)), increased until autumn and then decreased in species-specific patterns. Values of Vcmax(25) and Jmax(25) differed among species during winter. There was a positive correlation of Vcmax(25) with area-based nitrogen concentration among leaves during winter in Camellia and Photinia. Interspecific differences in Vcmax(25) were responsible for interspecific differences in light-saturated rates of net photosynthesis during winter. PMID:16356922

  2. Energy and water exchanges from a temperate pine plantation forest

    Restrepo, N. C.; Arain, M. A.

    2005-01-01

    This paper summarizes the energy and water vapour fluxes for the first 14 months at a newly initiated flux tower site at a 65-year-old temperate conifer forest (Pinus strobus L.) in southern Ontario, Canada. These fluxes have been measured continuously since February 2002 using the eddy covariance technique as a part of long-term tower flux measurement programme over a chronosequence of white pine stands. The site is located 12 km south of Simcoe, near Turkey Point in St Williams Forest Tract, owned and managed by the Ontario Ministry Natural Resources. The site was originally sandy, abandoned land, which was planted with conifer and deciduous forests. The trees are about 22 m in height. The mean trunk diameter of the trees is 33 cm and the stand stem density is 750 ha-1. Leaf area index is about 3·2 to 4·0. The soil is loamy fine sand and very fine sandy loam with low soil-moisture holding capacity. The closure of the daily mean energy balance (H + LE)/(Rn - G - S) was 0·90. Typical values of midday Bowen ratio (H/LE) in the growing season were approximately 1·4, whereas the midday Bowen ratio values for the winter season were typically 14 to 25. Surface conductance followed variations in solar radiation and vapour pressure deficit. In the growing season, surface conductance values were typically 5-12 mm s-1. Transpiration mainly responded to vapour pressure deficit, rather than surface conductance. However, on warm summer days, when soil moisture was low, vapour pressure deficit exerted strong control on canopy conductance, thereby reducing photosynthetic uptake and water loss. Priestley-Taylor α values were low during most of the growing season, indicating dry soil conditions and conservative water loss. In the growing season, maximum daily evaporation values were 3·4 mm day-1. In winter, maximum observed evaporation was 0·05-0·2 mm day-1, mostly as a result of snow sublimation. Total calculated evapotranspiration for the 14 month measurement period was 465 +/- 93 mm, and the total measured precipitation was 996 mm, indicating approximately 47% of water loss in the form of evapotranspiration. Copyright

  3. Learning through a Winter's Tale

    Vidotto, Kristie

    2010-01-01

    In this article, the author shares her experience during the final semester of Year 11 Theatre Studies when she performed a monologue about Hermione from "The Winter's Tale". This experience was extremely significant to her because it nearly made her lose faith in one of the most important parts of her life, drama. She believes this experience,…

  4. Winter Weather Frequently Asked Questions

    ... Disasters & Severe Weather Earthquakes Extreme Heat Floods Hurricanes Landslides Tornadoes Tsunamis Volcanoes Wildfires Winter Weather Language: English Español (Spanish) File Formats Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF ...

  5. 23. Nordic geological winter meeting

    317 abstracts have been submitted for the 23rd Nordic Geological Winter Meeting in Aarhus (DK) on the 13 - 16 January 1998. Those relevant for petroleum, gas and gas hydrates exploration as well as for elucidation of paleoclimatic phenomena have been selected. The natural fission reactors as a natural analogue for radioactive waste disposal have been discussed as well. (EG)

  6. Parallel tempering in full QCD with Wilson fermions

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

    2001-01-01

    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 essential improve...

  7. Development of temper bead welding by under water laser welding

    Toshiba has developed temper bead welding by under water laser welding as SCC counter measure for aged components in PWR and BWR nuclear power plants. Temper bead welding by under water laser welding technique recovers toughness of low alloy steel reactor vessel by employing proper the number of cladding layers and their welding conditions. In this report, some evaluation results of material characteristics of temper bead welded low alloy steel are presented. (author)

  8. Simulated Tempering and Swapping on Mean-Field Models

    Bhatnagar, Nayantara; Randall, Dana

    2015-01-01

    Simulated and parallel tempering are families of Markov Chain Monte Carlo algorithms where a temperature parameter is varied during the simulation to overcome bottlenecks to convergence due to multimodality. In this work we introduce and analyze the convergence for a set of new tempering distributions which we call \\textit{entropy dampening}. For asymmetric exponential distributions and the mean field Ising model with and external field simulated tempering is known to converge slowly. We show...

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

    Liu Xue; Tao Zhi-Yong; Fang Qiang; Wang Xue-Mei; Zhang Hui; Stoute Jose A; Xia Hui; Cui Liwang

    2012-01-01

    Abstract 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 mali...

  10. Winter speed-up during a quiescent phase of surge-type glaciers: observations and implications

    Abe, T.; Furuya, M.

    2014-12-01

    Glacier surface velocity is a combination of the internal deformation of ice and basal slip (including till deformation overlying bedrock) (Cuffey and Paterson, 2010). Short-term velocity changes can be attributed to basal slip associated with water pressure changes because of both the seasonal meltwater input and the evolution of the englacial and subglacial hydrological system. Thus, examining the velocity changes with high spatial and temporal resolution is helpful to understand how subglacial conditions evolve and control the surface velocities. We examined spatial and temporal velocity changes at quiescent surge-type glaciers near the border of Alaska/Yukon by SAR offset tracking and found significant acceleration from fall to winter regardless of surge events. Moreover, whereas the upstream propagating summer speed-up was observed, the winter speed-up propagated from upstream to downstream. Lingle and Fatland (2003) proposed the englacial water storages as the fundamental driver of temperate-glacier surge. Although our observations were performed at the quiescent and rather poly-thermal than temperate surge-type glaciers, our observations also support the englacial water storage hypothesis. Namely, the englacial water storages that do not directly connect to the surface can promote basal sliding through increased water pressure as winter approaches. Glacier surge often initiates in winter (Raymond, 1987), which has been explained by creep closure of efficient drainage system in fall and subsequent higher water pressure in winter. Mini-surges are also known in this area, and have been interpreted in a similar mechanism. However, in order to maintain the higher water pressure for some time period in winter, there should be such sources that can keep supplying the water to the bed. It has been uncertain, however, if, how and where the water can be stored in winter. Also, we should keep in mind that many of the previously known mini-surges were actually occurring in spring and summer (Kamb and Engelhardt, 1987; Harrison and Post, 2003). There are, to our knowledge, few comprehensive velocity observations in terms of both spatial and temporal coverages. Here we review some previous observations, place our observations in context of the glacier surge dynamics, and propose the winter speed-up mechanism.

  11. Control of weldability : Research leading to the development of two new quenched and tempered tool steels

    Hansson, Per

    2004-01-01

    The understanding of the hardenability is important in steel development with respect to weldability of steels as well as to the design of quenched and tempered steels.The common way to judge if steel is suitability to welding is the use of a carbon equivalent, which reflects the alloy content to the hardenability of the heat affected zone (HAZ). Most common of these equivalent is the IIW carbon equivalent wich has been in use for decades. However, this is an empirical equivalent, developed f...

  12. Drilling in tempered glass – modelling and experiments

    Nielsen, Jens Henrik

    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...... 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....

  13. Tempered Fractional Feynman-Kac Equation

    Wu, Xiaochao; Barkai, Eli

    2016-01-01

    Functionals of Brownian/non-Brownian motions have diverse applications and attracted a lot of interest of scientists. This paper focuses on deriving the forward and backward fractional Feynman-Kac equations describing the distribution of the functionals of the space and time tempered anomalous diffusion, belonging to the continuous time random walk class. Several examples of the functionals are explicitly treated, including the occupation time in half-space, the first passage time, the maximal displacement, the fluctuations of the occupation fraction, and the fluctuations of the time-averaged position.

  14. Trichinella in arctic, subarctic and temperate regions

    Kapel, C. M O

    The transmission and occurrence of Trichinella spp according to the zoogeography of different climatic conditions, socioeconomy and human activity are discussed. Comparing arctic, subarctic and temperate regions, it appears that the species of Trichinella present, the composition of the fauna and...... the human activity are all very important interacting factors affecting epidemiology. In Greenland, where only sylvatic trichinellosis is present, the high prevalence in wildlife appears closely connected with polar bear hunting. In the Scandinavian countries, the prevalence of both sylvatic and...... widespread wildlife populations may have epidemiological importance in relation to the recent changes in production and infrastructure in these former Soviet states....

  15. Robust Parameter Selection for Parallel Tempering

    Hamze, Firas; Dickson, Neil; Karimi, Kamran

    This paper describes an algorithm for selecting parameter values (e.g. temperature values) at which to measure equilibrium properties with Parallel Tempering Monte Carlo simulation. Simple approaches to choosing parameter values can lead to poor equilibration of the simulation, especially for Ising spin systems that undergo first-order phase transitions. However, starting from an initial set of parameter values, the careful, iterative respacing of these values based on results with the previous set of values greatly improves equilibration. Example spin systems presented here appear in the context of Quantum Monte Carlo.

  16. Robust Parameter Selection for Parallel Tempering

    Hamze, Firas; Karimi, Kamran

    2010-01-01

    This paper describes an algorithm for selecting parameter values (e.g. temperature values) at which to measure equilibrium properties with Parallel Tempering Monte Carlo simulation. Simple approaches to choosing parameter values can lead to poor equilibration of the simulation, especially for Ising spin systems that undergo $1^st$-order phase transitions. However, starting from an initial set of parameter values, the careful, iterative respacing of these values based on results with the previous set of values greatly improves equilibration. Example spin systems presented here appear in the context of Quantum Monte Carlo.

  17. A new approach to temperate generalized functions

    Delcroix, Antoine

    2008-01-01

    A new approach to the algebra G_{\\tau} of temperate nonlinear generalized functions is proposed, in which G_{\\tau} is based on the space O_{M} endowed with is natural topology in contrary to previous constructions. Thus, this construction fits perfectly in the general scheme of construction of Colombeau type algebras and reveals better properties of G_{\\tau}. This is illustrated by the natural introduction of a regularity theory in G_{\\tau}, of the Fourier transform, with the definition of G_{O_{C prime}}, the space of rapidly generalized distributions which is the Fourier image of G_{\\tau}.

  18. Extended Hamiltonian approach to continuous tempering.

    Gobbo, Gianpaolo; Leimkuhler, Benedict J

    2015-06-01

    We introduce an enhanced sampling simulation technique based on continuous tempering, i.e., on continuously varying the temperature of the system under investigation. Our approach is mathematically straightforward, being based on an extended Hamiltonian formulation in which an auxiliary degree of freedom, determining the effective temperature, is coupled to the physical system. The physical system and its temperature evolve continuously in time according to the equations of motion derived from the extended Hamiltonian. Due to the Hamiltonian structure, it is easy to show that a particular subset of the configurations of the extended system is distributed according to the canonical ensemble for the physical system at the correct physical temperature. PMID:26172654

  19. Myxomycetes associated with pipevine, a temperate liana

    Coelho IL

    2012-04-01

    Full Text Available Pinevine (Aristolochia macrophylla Lam., a climbing woody vine native to temperate forests of eastern North America, is morphologically similar to many of the lianas characteristic of moist tropical forests. In August 2010, samples of dead pinevine collected from a study site in the Great Smoky Mountains National Park were used to prepare a series of 50 moist chamber cultures. Thirty-seven of the 50 cultures (74% yielded evidence (either plasmodia or fruiting bodies of myxomycetes. Fourteen species representing seven genera were recorded, with members of the Trichiales (41% of all records and Physarales (49% of all records the most abundant.

  20. Structural mechanism of thermal brittleness in steels with tempered brittleness in steels with tempered bainite structure

    Tendency to temper brittleness was studied for low-alloy steels usually used in power machine-building. With the use of electron microscopy carbide phase distribution and changes of carbide particle size were determined in steels under long-term holding at 350 deg C. Relationships of yield strength, critical temperature of embrittlement to carbide phase parameters and fracture mode were established

  1. Nulhegan Deer Wintering Area Management Plan 1994

    US Fish and Wildlife Service, Department of the Interior — Within the Nulhegan basin lies the Nulhegan Deer Wintering Area, an approximately 15,000acre tract of land. In addition to being the largest deer wintering area in...

  2. Adhesion and wear properties of boro-tempered ductile iron

    Highlights: → In this study, the wear and adhesion properties of BDI were investigated. → Boro-tempering process under several heat treatment conditions was examined. → Optical microscope, SEM and XRD analysis were carried out to investigate the microstructure. → It was observed that boro-tempering process improves micro-hardness and wear properties of ductile irons. -- Abstract: In this study, adhesion and wear properties of boro-tempered ductile iron (BDI) were investigated. Boro-tempering was carried out on two stage processes i.e. boronizing and tempering. At the first stage, ductile iron samples were boronized by using pack process at 900 oC for 1, 3, and 5 h and then, secondly tempered at 250, 300, 350, and 400 oC for 1 h. X-ray diffraction (XRD) analysis of boro-tempered samples showed that FeB and Fe2B phases were found on the surface of the samples. The Daimler-Benz Rockwell-C adhesion test was used to assess the adhesion of boride layer. Test result showed that adhesion decreased with increasing boriding time and increased with increasing tempering temperature. Dry sliding wear tests of these samples were performed against Al2O3 ball at a constant sliding speed and loads of 5 and 10 N. Wear tests indicated that boro-tempering heat treatment increased wear resistance of ductile iron. In addition, it was found that while wear rate of boro-tempered samples decreased with increasing boriding time, there is no significant affect of tempering temperature on wear rate.

  3. Ecology of temperate salt-marsh fucoids. II. In situ growth of transplanted Ascophyllum nodosum ecads

    Brinkhuis, B.H.; Jones, R.F.

    1976-03-15

    Growth, in terms of length, weight, and number of branches and/or dichotomies, in transplanted specimens of Ascophyllum nodosum ecad scorpioides in a temperate salt marsh is described. The ecad scorpioides, when transplanted from its characteristic habitat on the mid-intertidal, Spartina alterniflora-dominated, marsh flats to a location near mean low-water developed characteristics normally associated with A. nodosum ecad mackaii. The growth of these plants was more rapid than those in the mid-intertidal region and was not affected by the shading of algal fronds by S. alterniflora. Unusually high temperatures and light intensities during the winter and spring months were major factors affecting growth in plants that were subjected to relatively long periods of tidal exposure. The presence of S. alterniflora during the summer months may act in a protective capacity for mid-intertidal ecad populations.

  4. Solar energy reflector for steel tempering

    Solar energy is a vital source of energy. It attracted the attention of many nations. In fact two aspects promote the use of solar energy specially for the low temperature heat treatment of metal: 1- Environmental protection. 2- Economical issue. The search for the implementation of solar energy as a source remains a key issue in widening the scope of solar energy application and use in industry. This paper is an attempt to explore the feasibility and efficiency of using solar reflector in the tempering treatment of steel. A solar reflector in constructed, basically by a rolled steel plate with glass mirror strips glued to the rolled steel plate. A heating chamber is constructed at the focal site of the parabola in which small steel specimens were placed and then under the effect of solar sun shine the temperature of the specimens raise and for a period of time they were subjected to tempering. The temperature in the chamber was monitored and it was found that it reaches 110 degree centigrade in the months July and August just past middy 12:35.(Author)

  5. Winter triticale breeding in Poland

    Winter triticale is becoming an important cereal crop in Poland, as its acreage is expected to reach 1 million ha in 1990. It is to occupy a large part of the rye growing area. Three cultivars are registered and 11 more are under official trials. The actual state of breeding in connection with the main goals is presented. Breeding methods leading to further progress are briefly discussed. (author). 4 refs, 1 tab

  6. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

    S. J. Lawson

    2014-08-01

    Full Text Available Dicarbonyls glyoxal and methylglyoxal have been measured with 2,4-dinitrophenylhydrazine (2,4-DNPH cartridges and high performance liquid chromatography (HPLC, optimised for dicarbonyl detection, in clean marine air over the temperate Southern Hemisphere (SH oceans. Measurements of a range of dicarbonyl precursors (volatile organic compounds, VOCs were made in parallel. These are the first in situ measurements of glyoxal and methylglyoxal over the remote temperate oceans. Six 24 h samples were collected in late summer (February–March over the Chatham Rise in the South West Pacific Ocean during the Surface Ocean Aerosol Production (SOAP voyage in 2012, while 34 24 h samples were collected at Cape Grim Baseline Air Pollution Station in late winter (August–September 2011. Average glyoxal mixing ratios in clean marine air were 7 ppt at Cape Grim, and 24 ppt over Chatham Rise. Average methylglyoxal mixing ratios in clean marine air were 28 ppt at Cape Grim and 12 ppt over Chatham Rise. The mixing ratios of glyoxal at Cape Grim are the lowest observed over the remote oceans, while mixing ratios over Chatham Rise are in good agreement with other temperate and tropical observations, including concurrent MAX-DOAS observations. Methylglyoxal mixing ratios at both sites are comparable to the only other marine methylglyoxal observations available over the tropical Northern Hemisphere (NH ocean. Ratios of glyoxal : methylglyoxal > 1 over Chatham Rise but 14 molecules cm−2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption, or use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much needed data to verify the presence of these short lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

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

    Navarro, Gabriel; Ruiz, Javier

    2013-12-01

    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.

  8. Influence of climate change on the flowering of temperate fruit trees

    Perez-Lopez, D.; Ruiz-Ramos, M.; Sánchez-Sánchez, E.; Centeno, A.; Prieto-Egido, I.; Lopez-de-la-Franca, N.

    2012-04-01

    It is well known that winter chilling is necessary for the flowering of temperate trees. The chilling requirement is a criterion for choosing a species or variety at a given location. Also chemistry products can be used for reducing the chilling-hours needs but make our production more expensive. This study first analysed the observed values of chilling hours for some representative agricultural locations in Spain for the last three decades and their projected changes under climate change scenarios. Usually the chilling is measured and calculated as chilling-hours, and different methods have been used to calculate them (e.g. Richarson et al., 1974 among others) according to the species considered. For our objective North Carolina method (Shaltout and Unrath, 1983) was applied for apples, Utah method (Richardson et al. 1974) for peach and grapevine and the approach used by De Melo-Abreu et al. (2004) for olive trees. The influence of climate change in temperate trees was studied by calculating projections of chilling-hours with climate data from Regional Climate Models (RCMs) at high resolution (25 km) from the European Project ENSEMBLES (http://www.ensembles-eu.org/). These projections will allow for analysing the modelled variations of chill-hours between 2nd half of 20C and 1st half of 21C at the study locations.

  9. Examination of carbon partitioning into austenite during tempering of bainite

    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.

  10. High order schemes for the tempered fractional diffusion equations

    Li, Can

    2014-01-01

    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...

  11. Simulation of Residual Stresses at Holes in Tempered Glass

    Nielsen, Jens Henrik; Olesen, John Forbes; Poulsen, Peter Noe; Stang, Henrik

    2010-01-01

    This work presents a full 3D numerical study of the residual stresses in tempered (toughened) glass near holes using Narayanaswamy’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...

  12. Simulated-tempering approach to spin-glass simulations

    Kerler, Werner; Rehberg, Peter

    1994-01-01

    After developing an appropriate iteration procedure for the determination of the parameters, the method of simulated tempering has been successfully applied to the 2D Ising spin glass. The reduction of the slowing down is comparable to that of the multicanonical algorithm. Simulated tempering has, however, the advantages to allow full vectorization of the programs and to provide the canonical ensemble directly.

  13. Carbon sequestration in managed temperate coniferous forests under climate change

    Dymond, C C; S. Beukema; C. R. Nitschke; K. D. Coates; R. M. Scheller

    2015-01-01

    Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management and...

  14. Examination of carbon partitioning into austenite during tempering of bainite

    García Caballero, Francisca; Miller, M. K.; Clarke, A J; García Mateo, Carlos

    2010-01-01

    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.

  15. Lithology, porosity and morphology influence on temperate low- and mid-altitudes cold screes susceptible to host permafrost

    Popescu, Razvan; Vespremeanu-Stroe, Alfred; Alexandru, Onaca; Cruceru, Nicolae

    2015-04-01

    The ventilated cold screes from the temperate regions develop high negative thermal anomalies (ground versus air annual temperature) in their lower parts due to cold air aspiration in wintertime, which support the formation of cold reservoirs and sometimes of the perennial frozen ground. Ground and air temperature monitoring, geophysical soundings, debris texture and porosity measurements and dendrogeomorphological analyses were applied at Detunata sites in Apuseni Mts (Western Romanian Carpathians) to investigate a low-altitude cold scree (ca. 1080 m) accommodated in basalt debris. The large negative anomalies (6 - 6.8 °C), the high resistivity values (up to 65 kΩm) recorded in late spring and mid-autumn and the dwarf forest occurrence (whose growth rates are ca. 3 times smaller than the common forest) support the permafrost presence. The new results were integrated into an inter-site evaluation based on the internationally reported cold screes which reveals the priority of lithology in controlling their thermal behavior and implicitly the cold reservoir formation or even permafrost into low- and mid-altitude cold screes. As long as the mean slope of debris exceeds a critical threshold (25°), the exceptional high porosity is the driving factor for an extensive and intensified chimney circulation responsible for the overcooling of the winter aspiration zone normally placed on the slope bottoms and on the negative features (depressions, furrows) in case of rock glacier - talus slope morphology. Lithology assessment highlights that most of the cold screes (ca. 2/3) are composed by only two rock types: basalts and limestones. The poor thermal-conductive basalts which built the most porous screes show the highest negative offsets (6 - 9 °C), which recommend them as the optimum rock type for the low-altitude permafrost sites ( 6 °C) that fade the exposure impact (most of the reported cases are western and southern exposed debris), but for the mid-altitude permafrost sites the slope exposure really count, as ca. 80% of them develop on the shadowed northern aspects.

  16. On the transgranular type of tempered martensite embrittlement

    Martensitic alloy steels are subject to tempering because of their low toughness in the as-quenched state. When tempered in the range of 250--400 C, however, the toughness drops in spite of the decrease in strength with increasing the tempering temperature. This phenomenon is referred to as tempered martensite embrittlement (TME). TME can be classified into two types according to the fracture mode; intergranular and transgranular TME. The transgranular type was suggested to be caused by the formation of coarse carbides at the lath boundaries following the decomposition of retained austenite. In this study, the transgranular type of TME has been analyzed in terms of impact toughness, fracture behavior and microstructure on isothermal tempering. The experimental alloy systems chosen are the Mo and MoW steels in which alloying elements, Mo and W, may decrease the intrinsic toughness and thus produce easy transgranular brittle fracture

  17. Kinetic of tempering hardened steels CH.1530 and CH.4732

    This paper presents the experimental results from the investigation of isothermal kinetic of hardness change for two types of hardened steel CH.1530 and CH.4732 received by tempering. The investigated steel have approximately an equal amount of carbon, but different alloying elements with intention to establish the influence of alloyed element of the tempering process. The obtained experimental results were numerically treated by formal kinetic analysis with developed kinetic mathematical model for dependence of the hardness from the tempering's parameters. The model establishes a hypothesis for the diffusions nature of the tempering process. The activation energy of the fourth elementary elementary process which characterizes the tempering process of martensite for two type investigated steels is given as well. (author)

  18. Effect of cohesive energy on thermal expansion behavior of T6 tempered 7A09 aluminum alloy

    Highlights: ► Transformation related to η’ and η can cause cohesive energy and volume changes. ► These changes can influence the variation trend of CTE for 7A09 alloy. ► Cohesive energy change becomes a main factor influencing CTE from Ostwald ripening stage. - Abstract: The dynamic effect of cohesive energy on the CTE of T6 (the highest strength temper) tempered 7A09 aluminum alloy was studied in this paper. Transmission electron microscopy (TEM) was combined with differential scanning calorimetry (DSC) to analyze the phase transitions of T6 tempered 7A09 aluminum alloy taking place in a heating process. The corresponding CTE curve was recorded by a thermal dilatometer. The ion-bonding model was utilized to estimate the variation of cohesive energy caused by the phase transitions. Results indicate that GPII zones and η′ phase are main precipitates in T6 tempered 7A09 alloy. During the heating process, the cohesive energy of alloy system increases with the transition from η′ to η phase and the precipitation of η phase. The dissolution of η phase leads to a decrease of cohesive energy. Although volume changes of alloy system have effects on the CTE, the effect of the cohesive energy change is more obvious than that of volume change after the precipitation of η phase begins in the Ostwald ripening stage. Effects of cohesive energy and volume changes can be expressed in the nonlinearity of CTE curve.

  19. Impacts of a changing winter precipitation regime on the Great Snowforest of British Columbia, Canada

    Knudsvig, H.; Dery, S. J.; Coxson, D.

    2012-12-01

    Rising air temperatures have profoundly impacted British Columbia (BC) mountain ecosystems, including its Interior Wetbelt. This region supports the sole Interior Temperate Rainforest (ITR), or perhaps more appropriately "snowforest", of North America. This snowforest encompasses about 30,500 km2 and contains Western redcedar (Thuja plicata) and western hemlock (Tsuga heteropylla) in excess of 1500 years old. This region is projected to be one of the more vulnerable biogeoclimatic zones in BC due to forest operations and climate change. Loss of snow as a storage medium has the potential to negatively affect the forest. A decrease in snow water equivalent (SWE) has the potential to decrease soil moisture values; impacts of decreased water availability in this region have the possibility to affect soil moisture storage, vegetative species composition, flora and fauna interdependence, and pathogen outbreaks. Given the projected climate change in high latitude and altitude areas, this project analyzes the contemporary and potential future climate of BC's Interior Wetbelt and explores the possible environmental and ecohydrological impacts of climate change on the snowforest. Models project an increase in air temperature and precipitation but a decrease in snowfall in this region. Analyses of the snow depth, SWE, and temperature from the Upper Fraser River Basin automated snow pillow sites of the BC River Forecast Centre (RFC) were conducted; snow depth, SWE, and temperature were also measured at the field site via automated weather stations and bi-monthly snow surveys. Surveys recorded depth and SWE after observed peak accumulation and continued until snowpack was depleted in 80% of the field site. To determine the influence of precipitation on the soil moisture levels in the ITR, soil moisture and water table levels were measured for the 2011-12 water year in addition to meteorological conditions; snow, spring water, and near surface ground water samples were collected and analyzed for the environmental isotopes of deuterium and oxygen-18. Analysis of the RFC's snow pillow data shows April 1 snow depth has been highly variable in the last 25 years with an overall decline in depth and SWE values. Soil moisture values at the study site were consistent through the year but showed a peak during spring melt and a decline during August, the driest month of summer in this region. Isotopic analysis on the water samples is on-going. The Upper Fraser River Basin experienced an above-normal to record snowpack the winter of 2011-12, thus observed values may not be indicative of the overall trend for this area. Trends in this interconnected ecosystem can assist in determining impacts of climate change to northern climates.

  20. Mercury in wintering seabirds, an aggravating factor to winter wrecks?

    Fort, Jérôme; Lacoue-Labarthe, Thomas; Nguyen, Hanh Linh; Boué, Amélie; Spitz, Jérôme; Bustamante, Paco

    2015-09-15

    Every year, thousands of seabirds are cast ashore and are found dead along the coasts of North America and Western Europe. These massive mortality events called 'winter wrecks' have generally been attributed to harsh climatic conditions and prolonged storms which affect bird energy balance and impact their body condition. Nevertheless, additional stress factors, such as contaminant body burden, could potentially cumulate to energy constraints and actively contribute to winter wrecks. However, the role played by these additional factors in seabird massive winter mortality has received little attention to date. In February/March 2014, an unprecedented seabird wreck occurred along the Atlantic French coasts during which > 43,000 seabirds were found dead. By analyzing mercury (Hg) concentrations in various tissues collected on stranded birds, we tested the hypothesis that Hg played a significant role in this mortality. More specifically, we aimed to (1) describe Hg contamination in wintering seabirds found along the French coasts in 2014, and (2) determine if Hg concentrations measured in some vital organs such as kidney and brain reached toxicity thresholds that could have led to deleterious effects and to an enhanced mortality. We found some of the highest Hg levels ever reported in Atlantic puffins, common guillemots, razorbills and kittiwakes. Measured concentrations ranged from 0.8 to 3.6 μg · g(-1) of dry weight in brain, 1.3 to 7.2 μg · g(-1) in muscle, 2.5 to 13.5 μg · g(-1) in kidney, 2.9 to 18.6 μg · g(-1) in blood and from 3.1 to 19.5 μg · g(-1) in liver. Hg concentrations in liver and brain were generally below the estimated acute toxicity levels. However, kidney concentrations were not different than those measured in the liver, and above levels associated to renal sub-lethal effects, suggesting a potential Hg poisoning. We concluded that although Hg was not directly responsible for the high observed mortality, it has been a major aggravating stress factor for emaciated birds already on the edge. Importantly, this study also demonstrated that total blood, which can be non-lethally collected in seabirds, can be used as a predictor of Hg contamination in other tissues. PMID:25984703

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

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

    2013-12-01

    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.

  2. On the tempering of bainite structure

    Some peculiarities of the upper bainite structure which determine thermal stability and effect of these peculiarities on the 25KhN3MFA steel properties are studied. Metallographic and X-ray diffraction analyses, dilatometric measurements and tension tests of samples have been made. It is found that the structure formed at the decomposition of supercooled austenite in the upper bainite temperature interval is characterized by the stable defect system, and that why it posesses a higher thermal stability than martensite. It is shown that the decomposition of residual austenite occurs in the process of tension tests of bainite samples. It leads to the increase in strength and to the decrease in ductility of the steel as compared with the structure of the tempered martensite

  3. Temperate Ice Depth-Sounding Radar

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

    2008-12-01

    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

  4. Psychosocial correlates of severe temper tantrums.

    Needlman, R; Stevenson, J; Zuckerman, B

    1991-04-01

    Temper tantrums are common and distressing, but little epidemiological information is available about them. Attempts to identify psychosocial correlates of tantrums have used small samples and have not controlled for multiple concurrent behavior problems. We analyzed interviews from 502 English mothers of 3-year-olds. Tantrums were considered present if mothers reported tantrums three or more times a day or lasting 15 minutes or longer. Behavior problems were assessed using the Behavior Screening Questionnaire. Tantrums were reported in 6.8% of children, of whom 52% had multiple behavior problems. Factors independently associated with tantrums included maternal depression and irritability, low education, and use of corporal punishment, manual social class, marital stress, child care provided exclusively by the mother, and poor child health. Tantrums were not associated (at p less than 0.01) with gender, maternal employment, low social support, or single parenthood. Severe tantrums may indicate the presence of multiple behavior problems and psychosocial stressors. PMID:2045487

  5. Study on tempering behaviour of AISI 410 stainless steel

    Martensitic stainless steels find extensive applications due to their optimum combination of strength, hardness and wear-resistance in tempered condition. However, this class of steels is susceptible to embrittlement during tempering if it is carried out in a specific temperature range resulting in significant reduction in toughness. Embrittlement of as-normalised AISI 410 martensitic stainless steel, subjected to tempering treatment in the temperature range of 673–923 K was studied using Charpy impact tests followed by metallurgical investigations using field emission scanning electron and transmission electron microscopes. Carbides precipitated during tempering were extracted by electrochemical dissolution of the matrix and identified by X-ray diffraction. Studies indicated that temper embrittlement is highest when the steel is tempered at 823 K. Mostly iron rich carbides are present in the steel subjected to tempering at low temperatures of around 723 K, whereas chromium rich carbides (M23C6) dominate precipitation at high temperature tempering. The range 773–823 K is the transition temperature range for the precipitates, with both Fe2C and M23C6 types of carbides coexisting in the material. The nucleation of Fe2C within the martensite lath, during low temperature tempering, has a definite role in the embrittlement of this steel. Embrittlement is not observed at high temperature tempering because of precipitation of M23C6 carbides, instead of Fe2C, preferentially along the lath and prior austenite boundaries. Segregation of S and P, which is widely reported as one of the causes for temper embrittlement, could not be detected in the material even through Auger electron spectroscopy studies. - Highlights: • Tempering behaviour of AISI 410 steel is studied within 673–923 K temperature range. • Temperature regime of maximum embrittlement is identified as 773–848 K. • Results show that type of carbide precipitation varies with temperature of tempering. • Mostly iron rich Fe2C carbides are present in the embrittlement temperature range. • With the precipitation of M23C6 carbides, recovery from the embrittlement begins

  6. Communicating Certainty About Nuclear Winter

    Robock, A.

    2013-12-01

    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.

  7. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

    Lawson, S. J.; Selleck, P. W.; Galbally, I. E.; Keywood, M. D.; Harvey, M. J.; Lerot, C.; Helmig, D.; Ristovski, Z.

    2014-08-01

    Dicarbonyls glyoxal and methylglyoxal have been measured with 2,4-dinitrophenylhydrazine (2,4-DNPH) cartridges and high performance liquid chromatography (HPLC), optimised for dicarbonyl detection, in clean marine air over the temperate Southern Hemisphere (SH) oceans. Measurements of a range of dicarbonyl precursors (volatile organic compounds, VOCs) were made in parallel. These are the first in situ measurements of glyoxal and methylglyoxal over the remote temperate oceans. Six 24 h samples were collected in late summer (February-March) over the Chatham Rise in the South West Pacific Ocean during the Surface Ocean Aerosol Production (SOAP) voyage in 2012, while 34 24 h samples were collected at Cape Grim Baseline Air Pollution Station in late winter (August-September) 2011. Average glyoxal mixing ratios in clean marine air were 7 ppt at Cape Grim, and 24 ppt over Chatham Rise. Average methylglyoxal mixing ratios in clean marine air were 28 ppt at Cape Grim and 12 ppt over Chatham Rise. The mixing ratios of glyoxal at Cape Grim are the lowest observed over the remote oceans, while mixing ratios over Chatham Rise are in good agreement with other temperate and tropical observations, including concurrent MAX-DOAS observations. Methylglyoxal mixing ratios at both sites are comparable to the only other marine methylglyoxal observations available over the tropical Northern Hemisphere (NH) ocean. Ratios of glyoxal : methylglyoxal > 1 over Chatham Rise but methylglyoxal in the remote marine boundary layer and explain at most 1-3 ppt of dicarbonyls observed, corresponding to 11 and 17% of the observed glyoxal and 28 and 10% of the methylglyoxal at Chatham Rise and Cape Grim, respectively, highlighting a significant but as yet unknown production mechanism. Glyoxal surface observations from both sites were converted to vertical columns and compared to average vertical column densities (VCDs) from GOME-2 satellite retrievals. Both satellite columns and in situ observations are higher in summer than winter, however satellite vertical column densities exceeded the surface observations by more than 1.5 × 1014 molecules cm-2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption, or use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much needed data to verify the presence of these short lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

  8. Effect of rare earths on cold brittleness and temper brittleness and temper brittleness of structural steels

    The following problems are discussed: the possibility to bind phosphorus in steel with rare-earth metals and concentrations of these metals; the effect produced on mechanical properties of steels at static and dynamic tests. The study has been made on the 35KhGS and 38KhS steels prone to reversible temper brittleness. It is shown that small practically adopted (up to 0.15%) additions of rare-earth metals to structural steels do not produce any significant effect on the position of cold brittleness threshold after improvement and additional embrittling tempering. Alloying Cr-Mn-Si steels with large additions of rare-earth metals (0.40 to O.65%) shifts the cold brittleness threshold of the improved steel by more than 100 deg C towards the region of low temperatures and practically eliminates its tendency to reversible temper brittleness. It has been established as a result of micro-X-ray spectrum studies that rare-earth metals do not produce alloying effect on the solid solution and do not enrich grain boundaries but can be found as a whole in nonmetallic inclusions. It is demonstrated that the main reason for the considerably lower cold brittleness threshold in the alloying with large additions of rare-earth metals lies in the fact that they bind phosphorus and its analogues into nonmetallic inclusions

  9. Seasonal performance of an outdoor constructed wetland for graywater treatment in a temperate climate.

    Jokerst, Adam; Sharvelle, Sybil E; Hollowed, Margaret E; Roesner, Larry A

    2011-12-01

    The seasonal treatment efficiency of a pilot-scale constructed wetland system located outdoors in a semi-arid, temperate climate was evaluated for graywater in a comprehensive, 1-year study. The system consisted of two wetland beds in series--a free water surface bed followed by a subsurface flow bed. Water quality monitoring evaluated organics, solids, nutrients, microbials, and surfactants. The results showed that the wetland substantially reduced graywater constituents during fall, spring, and summer, including biochemical oxygen demand (BOD) (92%), total nitrogen (85%), total phosphorus (78%), total suspended solids (TSS) (73%), linear alkylbenzene sulfonate (LAS) surfactants (94%), and E. coli (1.7 orders of magnitude). Except for TSS, lower removals of graywater constituents were noted in winter--BOD (78%), total nitrogen (64%), total phosphorus (65%), LAS (87%), and E. coli (1.0 order), indicating that, although wetland treatment slowed during the winter, the system remained active, even when the average water temperature was 5.2 +/- 4.5 degrees C. PMID:22368961

  10. Midlatitude tropical interactions during winter

    Chang, C. P.

    1985-01-01

    Pre-FGGE and FGGE/MONEX data are used to identify short term midlatitude tropical and longitudinal interactions during the winter monsoon. These interactions occur as cold surges, which develop over the East Asian continent and penetrate deep into the tropics with fast gravity wave speed. The observed interactions that occur after a surge include cyclogenesis and enhanced convection in the equatorial region, feedback from equatorial convection to midlatitude circulation systems, tropical east-west (Walker) circulations, and cross-equatorial influence. These interactions are also studied theoretically by analytical solutions of linearized shallow water equations. Response to transient forcing (monsoon surges) are mainly in Rossby and Kelvin modes. When the forcing time scale is short, significant gravity modes are also excited. The responses closely resemble observed winter monsoon flow. Responses to stationary forcing show that deep (barotropic) motions propagate energy away into high latitudes and that shallow (baroclinic) motions are trapped around the equator. It is shown that the barotropic teleconnection-type response to tropical sources found in previous numerical studies was due to the specified vertical wind shear and surface friction.

  11. Winter therapy for the accelerators

    Corinne Pralavorio

    2016-01-01

    Hundreds of people are hard at work during the year-end technical stop as all the accelerators are undergoing maintenance, renovation and upgrade operations in parallel.   The new beam absorber on its way to Point 2 before being lowered into the LHC tunnel for installation. The accelerator teams didn’t waste any time before starting their annual winter rejuvenation programme over the winter. At the end of November, as the LHC ion run was beginning, work got under way on the PS Booster, where operation had already stopped. On 14 December, once the whole complex had been shut down, the technical teams turned their attention to the other injectors and the LHC. The year-end technical stop (YETS) provides an opportunity to carry out maintenance work on equipment and repair any damage as well as to upgrade the machines for the upcoming runs. Numerous work projects are carried out simultaneously, so good coordination is crucial. Marzia Bernardini's team in the Enginee...

  12. Examination of carbon partitioning into austenite during tempering of bainite

    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

    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.

  13. THE SILICON EFFECT IN THE TEMPERING OF MARTENSITE IN STEELS

    Chang, Li; Smith, G.

    1984-01-01

    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 in...

  14. Non destructive evaluation of temper embrittlement of martensitic stainless steel

    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)

  15. 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

    Telmo Pereyra; Héctor Pagliaricci; Alfredo Ohanian

    2008-01-01

    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...

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

    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)

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

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

    2014-04-01

    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.

  18. A comparison of air particulate matter and associated polycyclic aromatic hydrocarbons in some tropical and temperate urban environments

    Panther, B. C.; Hooper, M. A.; Tapper, N. J.

    A 12 month study of urban concentrations of total suspended particulates (TSP) and 20 polycyclic aromatic hydrocarbons (PAH) was carried out in Seoul (South Korea), Hong Kong, Bangkok (Thailand), Jakarta (Indonesia) and Melbourne (Australia). Concentrations of particulate matter in the atmosphere varied widely between the cities over the course of the study, ranging from a low of 24.1 μg m -3 in Melbourne during the winter to a high of 376.2 μg m -3 in Jakarta during the dry season. Seasonal variations in both TSP and PAH were observed in the tropical cities in the study with higher concentrations during the dry season and lower concentrations during the wet season. TSP and PAH concentrations are correlated with each other in these cities, suggesting that they have related sources and sinks for these cities. In the temperate cities of Melbourne and Seoul, PAH concentrations were higher during the cold winter season and lower during the warm summer. However, TSP was quite variable over the years in these latter cities and no clear seasonal trend was observed. A number of factors have been investigated which could be contributing to seasonal variations in pollutant levels. In the temperate climates, increased emissions due to the use of fossil fuels for heating in the winter is evident. However, an interrogation of the database with respect to the other factors such as (1) increased photolytic degradation during the summer, (2) transport of pollutants from other sources, (3) removal of PAH via wet deposition and in-cloud scavenging mechanisms and (4) volatilisation of lower molecular weight species during periods of high temperature indicates the importance of multiple processes. Even though there are clearly much lower levels of both particulates and PAH in the wet season of the tropical climates, no statistically significant correlations have been observed between rainfall levels and pollutant concentrations.

  19. Winter warming from large volcanic eruptions

    Robock, Alan; Mao, Jianping

    1992-01-01

    An examination of the Northern Hemisphere winter surface temperature patterns after the 12 largest volcanic eruptions from 1883-1992 shows warming over Eurasia and North America and cooling over the Middle East which are significant at the 95-percent level. This pattern is found in the first winter after tropical eruptions, in the first or second winter after midlatitude eruptions, and in the second winter after high latitude eruptions. The effects are independent of the hemisphere of the volcanoes. An enhanced zonal wind driven by heating of the tropical stratosphere by the volcanic aerosols is responsible for the regions of warming, while the cooling is caused by blocking of incoming sunlight.

  20. Enhanced Sampling in the Well-Tempered Ensemble

    Bonomi, M

    2009-01-01

    We introduce the well-tempered ensemble (WTE) which is the biased ensemble sampled by well-tempered metadynamics when the energy is used as collective variable. WTE can be designed so as to have approximately the same average energy as the canonical ensemble but much larger fluctuations. These two properties lead to an extremely fast exploration of phase space. An even greater efficiency is obtained when WTE is combined with parallel tempering. Unbiased Boltzmann averages are computed on the fly by a recently developed reweighting method [M. Bonomi et al. J. Comput. Chem. 30, 1615 (2009)]. We apply WTE and its parallel tempering variant to the 2d Ising model and to a Go-model of HIV protease, demonstrating in these two representative cases that convergence is accelerated by orders of magnitude.

  1. Convolution of n-dimensional Tempered Ultradistributions and Field Theory

    Bollini, C G

    2003-01-01

    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 product of two arbitrary even (in the variables $x^0$ and $r$) four dimensional distributions of exponential type is defined via the convolution of its corresponding Fourier Transforms. With this definition of convolution, we treat the problem of singular products of Green Functions in Quantum Field Theory. (For Renormalizable as well as for Nonrenormalizable Theories). Several examples of convolution of two Tempered Ultradistributions are given. In particular we calculate the convolution of two massless Wheeeler's propagators and the convolutio...

  2. The effects of climate stability on northern temperate forests

    Ma, Ziyu

    2016-01-01

    evolutionary relationship among species is known as phylogeny. Tree diversity was mapped using a phylogenetic supertree, covering species in the temperate forests of North America, Europe, and China. I found that Quaternary climate fluctuations limited phylogenetic endemism, which quantified unique...

  3. Computer simulation of quenched and tempered steel properties

    B. Smoljan

    2011-06-01

    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 500C (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.

  4. Nitrous oxide emission reduction in temperate biochar-amended soils

    Felber, R; R. Hüppi; Leifeld, J.; Neftel, A.

    2012-01-01

    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 incubation experiment two different temperate agr...

  5. Determining efficient temperature sets for the simulated tempering method

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

    2014-01-01

    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, ${\\mathcal T}_R = \\{T_1, T_2, \\ldots, T_R\\}$. For the simulated tempering (SP) 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 reg...

  6. Carbon sequestration in managed temperate coniferous forests under climate change

    Dymond, Caren C.; Beukema, Sarah; Nitschke, Craig R.; Coates, K. David; Scheller, Robert M.

    2016-01-01

    Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change in the Copper–Pine ...

  7. Effect of climate change on temperate forest ecosystems

    Brolsma, R.J.

    2010-01-01

    In temperate climates groundwater can have a strong effect on vegetation, because it can influence the spatio-temporal distribution of soil moisture and therefore water and oxygen stress of vegetation. Current IPCC climate projections based on CO2 emission scenarios show a global temperature rise and change in precipitation regime, which will affect hydrological and vegetation systems. This thesis provides a quantitative framework for studying eco-hydrology in groundwater influenced temperate...

  8. Contribution to the modelling of chocolate tempering process.

    Debaste, Frédéric; Kegelaers, Yves; Ben Amor, Hatem; Halloin, Véronique

    2007-01-01

    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...

  9. Measuring free energy in parallel tempering Monte Carlo

    Wang, Wenlong

    2015-01-01

    An efficient approach of measuring the absolute free energy in parallel tempering Monte Carlo using the exponential averaging method is discussed and the results are compared with those of population annealing Monte Carlo using the three-dimensional Edwards-Anderson Ising spin glass model as benchmark tests. Numerical results show that parallel tempering, even though uses a much less number of temperatures than population annealing, can nevertheless equally efficiently measure the absolute fr...

  10. Tempering and Annealing in a Verdier-Stockmayer Polymer

    E. R. Obias

    2004-12-01

    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.

  11. Tempering and Annealing in a Verdier-Stockmayer Polymer

    E. R. Obias; Banzon, R. S.

    2004-01-01

    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.

  12. Method for heating, forming and tempering a glass sheet

    Boaz, Premakaran Tucker; Sitzman, Gary W.

    1998-01-01

    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.

  13. Post-weld Tempered Microstructure and Mechanical Properties of Hybrid Laser-Arc Welded Cast Martensitic Stainless Steel CA6NM

    Mirakhorli, Fatemeh; Cao, Xinjin; Pham, Xuan-Tan; Wanjara, Priti; Fihey, Jean-Luc

    2016-01-01

    Manufacturing of hydroelectric turbine components involves the assembly of thick-walled stainless steels using conventional multi-pass arc welding processes. By contrast, hybrid laser-arc welding may be an attractive process for assembly of such materials to realize deeper penetration depths, higher production rates, narrower fusion, and heat-affected zones, and lower distortion. In the present work, single-pass hybrid laser-arc welding of 10-mm thick CA6NM, a low carbon martensitic stainless steel, was carried out in the butt joint configuration using a continuous wave fiber laser at its maximum power of 5.2 kW over welding speeds ranging from 0.75 to 1.2 m/minute. The microstructures across the weldment were characterized after post-weld tempering at 873 K (600 °C) for 1 hour. From microscopic examinations, the fusion zone was observed to mainly consist of tempered lath martensite and some residual delta-ferrite. The mechanical properties were evaluated in the post-weld tempered condition and correlated to the microstructures and defects. The ultimate tensile strength and Charpy impact energy values of the fully penetrated welds in the tempered condition were acceptable according to ASTM, ASME, and industrial specifications, which bodes well for the introduction of hybrid laser-arc welding technology for the manufacturing of next generation hydroelectric turbine components.

  14. Influence of tempering temperature on mechanical properties of cast steels

    G. Gola?ski

    2008-12-01

    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.

  15. Coastal zone

    The report entitled Climate Change Impacts and Adaptation : A Canadian Perspective, presents a summary of research regarding the impacts of climate change on key sectors over the past five years as it relates to Canada. This chapter on the coastal zone focuses on the impact of climate change on Canada's marine and Great Lakes coasts with tips on how to deal with the impacts associated with climate change in sensitive environments. This report is aimed at the sectors that will be most affected by adaptation decisions in the coastal zone, including fisheries, tourism, transportation and water resources. The impact of climate change in the coastal zone may include changes in water levels, wave patterns, storm surges, and thickness of seasonal ice cover. The Intergovernmental Panel on Climate Change projects global average sea level will rise between 9 and 88 centimetres between 1990 to 2100, but not all areas of Canada will experience the same rate of future sea level change. The main physical impact would be shoreline change that could result in a range of biophysical and socio-economic impacts, some beneficial, some negative. The report focuses on issues related to infrastructure and communities in coastal regions. It is noted that appropriate human adaptation will play a vital role in reducing the extent of potential impacts by decreasing the vulnerability of average zone to climate change. The 3 main trends in coastal adaptation include: (1) increase in soft protection, retreat and accommodation, (2) reliance on technology such as geographic information systems to manage information, and (3) awareness of the need for coastal adaptation that is appropriate for local conditions. 61 refs., 7 figs

  16. Development of passive design zones in China using bioclimatic approach

    This paper presents the work on development of passive design zones for different climates in China. A total of 18 cities representing the five major climatic types, namely severe cold, cold, hot summer and cold winter, mild and hot summer and warm winter were selected for climatic analysis. Measured weather data were gathered and analysed. A bioclimatic approach was adopted in which the comfort zone and 12 monthly climatic lines were determined and plotted on the psychrometric chart for each city. From these bioclimatic charts, the potential use of passive design strategies such as solar heating, natural ventilation, thermal mass with/without night ventilation and evaporative cooling was assessed. A total of nine passive design strategy zones were identified, and appropriate design strategies suggested for both summer and winter consideration

  17. Development of passive design zones in China using bioclimatic approach

    Lam, Joseph C. [Building Energy Research Group, Department of Building and Construction, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Yang, Liu; Liu, Jiaping [School of Architecture, Xi' an University of Architecture and Technology, Shaanxi (China)

    2006-04-15

    This paper presents the work on development of passive design zones for different climates in China. A total of 18 cities representing the five major climatic types, namely severe cold, cold, hot summer and cold winter, mild and hot summer and warm winter were selected for climatic analysis. Measured weather data were gathered and analysed. A bioclimatic approach was adopted in which the comfort zone and 12 monthly climatic lines were determined and plotted on the psychrometric chart for each city. From these bioclimatic charts, the potential use of passive design strategies such as solar heating, natural ventilation, thermal mass with/without night ventilation and evaporative cooling was assessed. A total of nine passive design strategy zones were identified, and appropriate design strategies suggested for both summer and winter consideration. (author)

  18. 33 CFR 100.109 - Winter Harbor Lobster Boat Race, Winter Harbor, ME.

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race... Lobster Boat Race, Winter Harbor, ME. (a) Regulated area. The regulated area includes all waters of Winter... Coast Guard patrol commander may delay, modify, or cancel the race as conditions or...

  19. Does cold winter weather produce depressive symptoms?

    Garvey, Michael J.; Goodes, Mike; Furlong, Candy; Tollefson, Gary D.

    1988-06-01

    To examine whether harsh winter weather is associated with depressive symptoms, 45 healthy subjects from Minnesota were compared to 42 subjects from California near the end of the winter season. No differences in the prevalence of depressive symptoms were found between the two groups.

  20. Nuclear Winter: Scientists in the Political Arena

    Badash, Lawrence

    2001-03-01

    The nuclear winter phenomenon is used to illustrate the many paths by which scientific advice reaches decision makers in the United States government. Because the Reagan administration was hostile to the strategic policy that the scientific discovery seemed to demand, the leading proponent of nuclear winter, Carl Sagan, used his formidable talent for popularization to reach a larger audience.

  1. Endothermic heat production in honeybee winter clusters.

    Stabentheiner, Anton; Pressl, Helga; Papst, Thomas; Hrassnigg, Norbert; Crailsheim, Karl

    2003-01-01

    In order to survive cold northern winters, honeybees crowd tightly together in a winter cluster. Present models of winter cluster thermoregulation consider the insulation by the tightly packed mantle bees as the decisive factor for survival at low temperatures, mostly ignoring the possibility of endothermic heat production. We provide here direct evidence of endothermic heat production by 'shivering' thermogenesis. The abundance of endothermic bees is highest in the core and decreases towards the surface. This shows that core bees play an active role in thermal control of winter clusters. We conclude that regulation of both the insulation by the mantle bees and endothermic heat production by the inner bees is necessary to achieve thermal stability in a winter cluster. PMID:12477904

  2. Candidate Planets in the Habitable Zones of Kepler Stars

    Gaidos, Eric

    2013-01-01

    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 2738 candidate or ...

  3. Monitoring Change in Temperate Coniferous Forest Ecosystems

    Williams, Darrel (Technical Monitor); Woodcock, Curtis E.

    2004-01-01

    The primary goal of this research was to improve monitoring of temperate forest change using remote sensing. In this context, change includes both clearing of forest due to effects such as fire, logging, or land conversion and forest growth and succession. The Landsat 7 ETM+ proved an extremely valuable research tool in this domain. The Landsat 7 program has generated an extremely valuable transformation in the land remote sensing community by making high quality images available for relatively low cost. In addition, the tremendous improvements in the acquisition strategy greatly improved the overall availability of remote sensing images. I believe that from an historical prespective, the Landsat 7 mission will be considered extremely important as the improved image availability will stimulate the use of multitemporal imagery at resolutions useful for local to regional mapping. Also, Landsat 7 has opened the way to global applications of remote sensing at spatial scales where important surface processes and change can be directly monitored. It has been a wonderful experience to have participated on the Landsat 7 Science Team. The research conducted under this project led to contributions in four general domains: I. Improved understanding of the information content of images as a function of spatial resolution; II. Monitoring Forest Change and Succession; III. Development and Integration of Advanced Analysis Methods; and IV. General support of the remote sensing of forests and environmental change. This report is organized according to these topics. This report does not attempt to provide the complete details of the research conducted with support from this grant. That level of detail is provided in the 16 peer reviewed journal articles, 7 book chapters and 5 conference proceedings papers published as part of this grant. This report attempts to explain how the various publications fit together to improve our understanding of how forests are changing and how to monitor forest change with remote sensing. There were no new inventions that resulted from this grant.

  4. Inflatable Evergreen Polar Zone Dome (EPZD) Settlements

    Bolonkin, Alexander; Cathcart, Richard

    2007-01-01

    Sustaining human life at the Earth antipodal Polar Regions is very difficult especially during Winter when water-freezing air temperature, blizzards and whiteouts make normal human existence dangerous. To counter these environmental stresses, we offer the innovative artificial Evergreen Polar Zone Dome (EPZD), an inflated half-hemisphere with interiors continuously providing a Mediterranean Sea-like climate. The Evergreen EPZD structural theory is developed, substantiated by key computations ...

  5. Scorecard on winter weather forecast

    Richman, Barbara T.

    A comparison of the observed temperatures and precipitation for this past winter (maps on left) with predicted temperatures and precipitation (maps on right) shows that the National Weather Service (NWS) temperature prediction was below par, but that the NWS precipitation forecast was ‘quite good,’ according to Don L. Gilman, chief of the NWS long-range forecast branch. The predictions, issued November 29, 1982 (Eos, December 14, 1982, p. 1211), covered December, January, and February.NWS long-range forecasters had thought that frigid Arctic air would swoop far south to bring below-normal temperatures to the western United States. Instead, an east Pacific trough, which may have been the strongest since 1900, brought a strong influx of air from the west, according to Gilman. The intense, low-pressure anomaly in the east Pacific, with the strong westerly winds, teamed with heavy rains south and southwest of Hawaii and warm equatorial Pacific waters to bring warm, wet air to the western United States. The results (see maps): Throughout most of the country, observed temperatures were above normal (A) or normal (N), while observed precipitation was heavy (H) o r normal (no code). Below-normal temperatures (B) occurred only in a portion of the southcentral U.S. and the Florida Keys. Light precipitation (L) fell over two patches in the northern plains, in the Appalachian region, and along the Maine coast.

  6. Net ecosystem exchange of CO2 and carbon balance for eight temperate organic soils under agricultural management

    Elsgaard, Lars; Görres, C.-M.; Hoffmann, Carl Christian; Blicher-Mathiesen, Gitte; Schelde, Kirsten; Petersen, Søren O

    2012-01-01

    This study presents the first annual estimates of net ecosystem exchange (NEE) of CO2 and net ecosystem carbon balances (NECB) of contrasting Danish agricultural peatlands. Studies were done at eight sites representing permanent grasslands (PG) and rotational (RT) arable soils cropped to barley...... and temperate climate zones. It was stressed that evaluation of emission factors should explicitly differentiate between data representing net C balance from a soil perspective and CO2-C balance from an atmospheric perspective. Modelling of inter-annual variability in NEE for three selected sites...

  7. Cyclic voles and shrews and non-cyclic mice in a marginal grassland within European temperate forest

    Zub, K.; Jędrzejewska, B.; Jędrzejewski, W.; Bartoń, K. A.

    2012-01-01

    Cyclic population dynamics of small mammals are not restricted to the boreal and arctic zones of Eurasia and North America, but long-term data series from lower latitudes are still less common. We demonstrated here the presence of periodic oscillations in small mammal populations in eastern Poland using 22-year (1986–2007) trapping data from marginal meadow and river valley grasslands located in the extensive temperate woodland of Białowieża Primeval Forest. The two most common species inhabi...

  8. High Temperal Resolution AOD Retrieval of Northern China in 2014 Winter Based on Geostationary Satellite Remote Sensing Data

    Chen, X.; Li, Z.; Zhang, Y.; Xu, H.; Ma, Y.; Li, D.; Lv, Y.; Qie, L.; Zhang, Y.; Li, L.; Liu, Y.

    2014-12-01

    Observations from satellite can provide large region, fast and dynamic monitoring of aerosol properties. Polar Satellites provide once a day of observations at most, which is difficult to monitor aerosol temporal variabilities clearly. Only geostationary orbit satellites have the ability to provide both high temporal and spatial resolution observations. The Korea Geostationary Ocean Color Imager (GOCI) onboard COMs-1 (Communication、Ocean & Meteorological Satellite-1) mainly designed for ocean observation, but it has a good potential for land monitoring. Cross calibration between GOCI and the US Moderate Resolution Imaging Spectrometer (MODIS) can improve the land radiation characteristics of GOCI, which can expand its ability in land observation.Cross calibration results show that the simulated TOA (Top Of Atmosphere) radiance from MODIS and GOCI measured TOA radiance agrees well. The geostationary orbit satellite observing characteristics of the nearly constant view geometry and the high temporal resolution were used in aerosol retrieval algorithm. For images of two adjacent time points, the difference of TOA radiance mostly comes from the change caused by aerosol. AOD retrievals were accomplished using a Look-Up Table (LUT) strategy with assumptions of quickly varied aerosol and slowly varied surface with time. The AOD retrieval algorithm calculates AOD by minimizing the surface reflectance variations of series observations in a short period of time, e.g. several days. GOCI data from January 1, 2014 to April 1, 2014 were used to retrieve AOD, when the haze was very heavy. The monitoring of hourly AOD variations were implemented during this period and the retrieved AOD agrees well with AREONET (AErosol RObotic NETwork) ground-based measurements. The result was also compared with MODIS AOD products. In conclusion, GOCI was calibrated using MODIS data firstly in order to improve the radiation characteristics of land; then, the AOD retrieval algorithm was developed based on time series GOCI data; third, the AOD retrieval algorithm was developed to retrieve AOD synchronously.In this paper, the GOCI data are used to retrieve AOD with higher temporal resolution, which is important to atmospheric environmental monitoring.

  9. TEM studies of tempered structural steels with Ni

    J. Pacyna

    2007-03-01

    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 2035 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 200C 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 200C 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.

  10. Effects of tempering on internal friction of carbon steels

    Research highlights: → Time tempering dependent microstructure of two steels is studied by internal friction. → Internal friction indicates the interactions of dislocations with carbon and carbides. → Internal friction detects the first stage of tempering. → 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.

  11. A note on the water budget of temperate glaciers

    J. Oerlemans

    2013-06-01

    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.

  12. Silent as a Winter Cuckoo

    Pad+ma dbang chen

    2012-12-01

    Full Text Available When my grandparents were children, parents were gods and their decisions about such issues as marriage and the choice of marriage partners were final. Children had no right to choose a spouse. Many parents found a daughter-in-law with a blood relationship for their son, believing this would better ensure family harmony. Consequently, many Tibetans struggled in sad marriages. Of course, parents hoped their children would have a good, stable life and not all arranged marriages were unhappy. When Grandfather was eighteen he herded sheep on our pastureland everyday. At that time, sheep and goats covered an enormous mountain that resembled a member of the Himalayas. Herders stayed together, played, told folktales, and sang folksongs. Some wrestled and others talked about their lovers. In many ways this daily gathering resembled a celebration of victory in battle. Grandfather and his lover, Dkon mchog mtsho, herded and had lunch together everyday. They went home from the pastureland and soon met again after supper, because they loved and needed each other as fish need water. They felt that they were the happiest people in the world, and hoped to marry. Everyone understood their intimate relationship and envied their loyalty to each other. Some other girls were especially jealous because Grandfather was handsome. In time, Great-grandfather discovered their relationship and resolved to end it. Grandfather was as silent as a winter cuckoo, because he was afraid of his father. However, he thought about how to convince his parents, or how to have a life with his lover. After some days he decided to elope, went to the place where he usually met Dkon mchog mtsho, and found her there. They looked longingly at each other as Dkon mchog mtsho's tears streamed down her red cheeks and seeped into the earth.

  13. The possible response of life zones in China under global climate change

    Chen, Xiongwen; Zhang, Xin-Shi; Li, Bai-Lian

    2003-09-01

    The response of natural vegetation to climate change is of global concern. In this research, an aggregated Holdridge Life Zone System was used to study the possible response of life zones in China under doubled atmospheric CO 2 concentration with the input climatic parameters at 0.5×0.5° resolution of longitude and latitude from NCAR regional climate model 2 (RegCM2) coupled with the CSIRO global climate model. The results indicate that the latitudinal distribution of life zones would become irregular because of the complicated climate change. In particular, new life zones, such as subtropical desert (SD), tropical desert (TDE) and tropical thorn woodland (TTW), would appear. Subtropical evergreen broadleaved forest (SEBF), tropical rainforest and monsoon forest (TRF), SD, TDE and TTW zones would appear in the northeastern China. Cool-temperate mixed coniferous and broadleaved forest (CMC) and warm-temperate deciduous broadleaved forest (WDBF) zones would appear at latitudes 25-35°N. The temperate desert (TD) in the western China would become Tibetan high-cold plateau (THP), SEBF, WDBF and temperate steppe (TS), and a large part of THP would be replaced by TRF, TDE, SEBF, TS and TTW. The relative area (distribution area/total terrestrial area) of CMC, TRF, TDE and TTW zone would increase about 3%, 21%, 3% and 6%, respectively. However, the relative area of SEBF, TS, TD and THP would decrease about 5%, 3%, 19% and 4%, respectively. In all, the relative area of forests (CCF, CMC, WDBF, SEBF, TRF) would increase about 15%, but the relative area of desert (TD, SD, TDE, and TTW) and THP would decrease about 9% and 4%, respectively. Therefore, responses of different life zones in China to climate change would be dramatic, and nationwide corridors should be considered for the conservation of migrating species under climate change.

  14. Tempered stable distributions stochastic models for multiscale processes

    Grabchak, Michael

    2015-01-01

    This brief is concerned with tempered stable distributions and their associated Levy processes. It is a good text for researchers interested in learning about tempered stable distributions.  A tempered stable distribution is one which takes a stable distribution and modifies its tails to make them lighter. The motivation for this class comes from the fact that infinite variance stable distributions appear to provide a good fit to data in a variety of situations, but the extremely heavy tails of these models are not realistic for most real world applications. The idea of using distributions that modify the tails of stable models to make them lighter seems to have originated in the influential paper of Mantegna and Stanley (1994). Since then, these distributions have been extended and generalized in a variety of ways. They have been applied to a wide variety of areas including mathematical finance, biostatistics,computer science, and physics.

  15. Radiation processing of temperate fruits of Kashmir valley

    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)

  16. Moessbauer spectroscopy analysis on a tempered martensitic 9% Cr steel

    Ramos, C. P., E-mail: ciramos@cnea.gov.ar [Centro Atomico Constituyentes, Departamento de Fisica (Argentina); Sztrajman, A.; Bianchi, R. [Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales (Argentina); Danon, C. A. [Centro Atomico Constituyentes, Departamento de Materiales (Argentina); Saragovi, C. [Centro Atomico Constituyentes, Departamento de Fisica (Argentina)

    2010-01-15

    We report an analysis by means of Moessbauer spectroscopy, on a 9% Cr steel submitted to a tempering process at 780 deg. C. Spectra of several samples with different tempering times obtained at room temperature are fitted, and a study on existent phases is made. From the former analysis, we infer the existence of different neighbors of the Fe atom governed by the concentration of alloying elements. In particular, we analyze the behavior of Cr, as the main substitutional atom. An additional measurement of samples at low velocities is made, aiming to reveal the existence of precipitated carbides. Finally a comparison between samples is performed, in order to obtain a detailed study of the effect of tempering time on hyperfine parameters.

  17. Resistance to small plastic strains during martensite tempering under tension

    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

  18. Moessbauer spectroscopy analysis on a tempered martensitic 9% Cr steel

    We report an analysis by means of Moessbauer spectroscopy, on a 9% Cr steel submitted to a tempering process at 780 deg. C. Spectra of several samples with different tempering times obtained at room temperature are fitted, and a study on existent phases is made. From the former analysis, we infer the existence of different neighbors of the Fe atom governed by the concentration of alloying elements. In particular, we analyze the behavior of Cr, as the main substitutional atom. An additional measurement of samples at low velocities is made, aiming to reveal the existence of precipitated carbides. Finally a comparison between samples is performed, in order to obtain a detailed study of the effect of tempering time on hyperfine parameters.

  19. Resistance to small plastic strains during martensite tempering under tension

    Zabil' skij, V.V.; Sarrak, V.I. (AN SSSR, Sverdlovsk. Inst. Fiziki Metallov)

    1982-11-01

    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.

  20. Overview of climatic effects of nuclear winter

    A general description of the climatic effects of a nuclear war are presented. This paper offers a short history of the subject, a discussion of relevant parameters and physical processes, and a description of plausible nuclear winter scenario. 9 refs

  1. Physical characteristics of Eurasian winter temperature variability

    Kim, Kwang-Yul; Son, Seok-Woo

    2016-04-01

    Despite the on-going global warming, recent winters in Eurasian mid-latitudes were much colder than average. In an attempt to better understand the physical characteristics for cold Eurasian winters, major sources of variability in surface air temperature (SAT) are investigated based on cyclostationary EOF analysis. The two leading modes of SAT variability represent the effect of Arctic amplification (AA) and the Arctic oscillation (AO), respectively. These two modes are distinct in terms of the physical characteristics, including surface energy fluxes and tropospheric circulations, and result in significantly different winter SAT patterns over the Eurasian continent. The AA-related SAT anomalies are dipolar with warm Arctic, centered at the Barents–Kara Seas, and cold East Asia. In contrast, the negative AO-related SAT anomalies are characterized by widespread cold anomalies in Northern Eurasia. Relative importance of the AA and the negative AO contributions to cold Eurasian winters is sensitive to the region of interest.

  2. Winter seismic vehicle impacts in permafrost terrain

    US Fish and Wildlife Service, Department of the Interior — Seismic exploration was conducted on the coastal plain of the Arctic National Wildlife Refuge, Alaska, during the winters of 1984 and 1985. Approximately 2000 km of...

  3. Unusial winter 2011/2012 in Slovakia

    Faško, P.; Lapin, M.; Matejovič, P.; Pecho, Jozef

    2012-01-01

    Roč. 15, č. 1 (2012), s. 19-26. ISSN 1335-339X Institutional support: RVO:68378289 Keywords : winter characteristics * climate variabilit * climate change * global warming Subject RIV: DG - Athmosphere Sciences, Meteorology

  4. Ultra low carbon bainitic (ULCB) steels after quenching and tempering

    The mechanical and Charpy V impact strength properties of new advanced ultra low carbon bainitic (ULBC) steels after water quenching and tempering (WQT) have been investigated. Their chemical compositions are given. The nine continuous cooling transformation diagrams (CCT) of the new ULCB steel grades have been established. The CCT diagrams for ULCBNi steels containing 9% Ni - grade 10N9 and 5% Ni - grade HN5MVNb are given. The comparison between CCT diagrams of 3.5%Ni + 1.5%Cu containing steels grade HSLA 100 and HN3MCu is shown. The effect of the increase in carbon and titanium contents in the chemical composition of ULCBMn steels 04G3Ti, 06G3Ti and 09G3Ti on the kinetics of phase transformations during continuous cooling is presented by the shifting CCT diagrams. The Charpy V impact strength and brittle fracture occurence curves are shown. The effect of tempering temperature on tensile properties of WQT HN3MCu steel is shown and Charpy V impact strength curves after different tempering conditions are shown. The optimum tempering temperatures region of HN3MCu steel for high Charpy V impact toughness at law temperatures - 80oC(193 K) and -120oC(153 K) is estimated. The effect of tempering temperature on mechanical properties of HN5MVNb steel is given. The low temperature impact Charpy V toughness of HN5MVNb steel is shown. The optimum range of tempering temperature during 1 hour for high toughness of WQT HN5MVNb steel is given. HN3MCu and HN5MVNb steels after WQT have high yield strength YS≥690 MPa and high Charpy V impact toughness KV≥80 J at -100oC (173K) and KCV≥50 J/cm2 at - 120oC (153K) so they may be used for cryogenic applications

  5. Sexually active bucks are efficient to stimulate female ovulatory activity during the anestrous season also under temperate latitudes.

    Chasles, Manon; Chesneau, Didier; Moussu, Chantal; Delgadillo, José Alberto; Chemineau, Philippe; Keller, Matthieu

    2016-05-01

    Goats are seasonal breeders and photoperiod is the main cue controlling the onset and offset of the breeding season. Nevertheless introducing a sexually active buck in a group of females during anestrous can stimulate their reproductive function and induce ovulation. This "male-effect" is very efficient under subtropical latitudes, when using sexually active males previously stimulated by a photoperiodic treatment. However, there is less evidence of its feasibility under temperate latitudes where the more important variation in day length could be responsible for a stronger inhibition of female sexual activity. The aim of this study was therefore to determine whether intense sexual activity can be induced in alpine bucks during the non-breeding season by a long-day treatment under temperate latitude and if these males could be used to produce an efficient male-effect. Bucks (n=21) were divided in two groups, one submitted to a photoperiodic treatment from November 1st to January 15th and then switched to natural photoperiod, while the other group remained entirely under the natural photoperiod. The ones submitted to this light treatment exhibit higher testicular volume and testosterone level 6 weeks after the end of the treatment. At the end of March, bucks were used to stimulate anestrous does (n=41) continuously for 15 days. We showed that (a) light treatment was efficient to induce an increase of sexual activity in bucks and (b) that the introduction of stimulated bucks among females induced a significantly higher proportion of ovulation in anestrous does than control bucks (86% vs 5%). Our results indicate that under temperate latitudes induction of ovulation in females during the anestrous season is feasible using bucks treated with long-days during winter. PMID:27006331

  6. Winter tourism in Portugal - encouraging its increase

    Garcia, Raul Ressano

    2014-01-01

    Every year between seventy thousand and one hundred thousand Portuguese practice winter sports,mainly skiing and snowboarding (Carvalho, 2006). Unfortunately for Portuguese tourism most of them go abroad to spend their money.Serra da Estrela is the only mountain where it is possible to practice winter sports in Portugal but it doesn’t attract many Portuguese. Problems with accessibility (Petur,2006) inexistency of accommodation near the ski slopes (Carvalho,2006) and not enough kilometers ...

  7. ENSO and winter storms in California

    Cayan, D.R.; Bromirski, Peter

    2003-01-01

    The frequency and intensity of North Pacific winter storms that penetrate the California coast drives the winds, sea level, precipitation and streamflow that are crucial influences on coastal processes. There is considerable variability of these storm characteristics, in large part owing to the El Nino/Southern Oscillation (ENSO} phenomenon. There is a great contrast of the storm characteristics during the El Nino phase vs. the La Nina phase, with the largest scale, southerly extensive winter storms generated during El Nino.

  8. Influence of tempering temperature on mechanical properties of cast steels

    G. Golański

    2008-01-01

    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 temperin...

  9. Redistribution of alloying elements during tempering of a nanocrystalline steel

    Redistribution of alloying elements during tempering of a novel nanocrystalline steel consisting of a mixture of lower bainitic ferrite and carbon-enriched retained austenite has been analyzed by atom probe tomography. Three physical processes, namely redistribution of substitutional solute across the austenite/bainitic ferrite interface before retained austenite decomposition, redistribution of solute across the lower bainite cementite/ferrite interface, and the precipitation of transition carbides and cementite, have been observed. Results suggest that retained austenite decomposes during tempering before full equilibrium is reached at the interface. Moreover, cementite precipitates from supersaturated ferrite via a paraequilibrium transformation mechanism

  10. Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.)

    Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

    2016-01-01

    Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association between chilling and methylation changes was observed, which suggested that chilling acquisition during dormancy in apple is likely to affect the epigenetic regulation through DNA methylation. PMID:26901339

  11. Chilling-Mediated DNA Methylation Changes during Dormancy and Its Release Reveal the Importance of Epigenetic Regulation during Winter Dormancy in Apple (Malus x domestica Borkh.).

    Kumar, Gulshan; Rattan, Usha Kumari; Singh, Anil Kumar

    2016-01-01

    Winter dormancy is a well known mechanism adopted by temperate plants, to mitigate the chilling temperature of winters. However, acquisition of sufficient chilling during winter dormancy ensures the normal phenological traits in subsequent growing period. Thus, low temperature appears to play crucial roles in growth and development of temperate plants. Apple, being an important temperate fruit crop, also requires sufficient chilling to release winter dormancy and normal phenological traits, which are often associated with yield and quality of fruits. DNA cytosine methylation is one of the important epigenetic modifications which remarkably affect the gene expression during various developmental and adaptive processes. In present study, methylation sensitive amplified polymorphism was employed to assess the changes in cytosine methylation during dormancy, active growth and fruit set in apple, under differential chilling conditions. Under high chill conditions, total methylation was decreased from 27.2% in dormant bud to 21.0% in fruit set stage, while no significant reduction was found under low chill conditions. Moreover, the demethylation was found to be decreased, while methylation increased from dormant bud to fruit set stage under low chill as compared to high chill conditions. In addition, RNA-Seq analysis showed high expression of DNA methyltransferases and histone methyltransferases during dormancy and fruit set, and low expression of DNA glcosylases during active growth under low chill conditions, which was in accordance with changes in methylation patterns. The RNA-Seq data of 47 genes associated with MSAP fragments involved in cellular metabolism, stress response, antioxidant system and transcriptional regulation showed correlation between methylation and their expression. Similarly, bisulfite sequencing and qRT-PCR analysis of selected genes also showed correlation between gene body methylation and gene expression. Moreover, significant association between chilling and methylation changes was observed, which suggested that chilling acquisition during dormancy in apple is likely to affect the epigenetic regulation through DNA methylation. PMID:26901339

  12. Controlling Effects of Irradiance and Heterotrophy on Carbon Translocation in the Temperate Coral Cladocora caespitosa

    Tremblay, Pascale; Ferrier-Pags, Christine; Maguer, Jean Franois; Rottier, Ccile; Legendre, Louis; Grover, Renaud

    2012-01-01

    Temperate symbiotic corals, such as the Mediterranean species Cladocora caespitosa, live in seasonally changing environments, where irradiance can be ten times higher in summer than winter. These corals shift from autotrophy in summer to heterotrophy in winter in response to light limitation of the symbionts photosynthesis. In this study, we determined the autotrophic carbon budget under different conditions of irradiance (20 and 120 mol photons m?2 s?1) and feeding (fed three times a week with Artemia salina nauplii, and unfed). Corals were incubated in H13CO3?-enriched seawater, and the fate of 13C was followed in the symbionts and the host tissue. The total amount of carbon fixed by photosynthesis and translocated was significantly higher at high than low irradiance (ca. 13 versus 2.54.5 g cm?2 h?1), because the rates of photosynthesis and carbon fixation were also higher. However, the percent of carbon translocation was similar under the two irradiances, and reached more than 70% of the total fixed carbon. Host feeding induced a decrease in the percentage of carbon translocated under low irradiance (from 70 to 53%), and also a decrease in the rates of carbon translocation per symbiont cell under both irradiances. The fate of autotrophic and heterotrophic carbon differed according to irradiance. At low irradiance, autotrophic carbon was mostly respired by the host and the symbionts, and heterotrophic feeding led to an increase in host biomass. Under high irradiance, autotrophic carbon was both respired and released as particulate and dissolved organic carbon, and heterotrophic feeding led to an increase in host biomass and symbiont concentration. Overall, the maintenance of high symbiont concentration and high percentage of carbon translocation under low irradiance allow this coral species to optimize its autotrophic carbon acquisition, when irradiance conditions are not favourable to photosynthesis. PMID:22970284

  13. Winter Dew Harvest in Mexico City

    Arias-Torres Jorge Ernesto

    2015-12-01

    Full Text Available This study presents experimental and theoretical results of winter dew harvest in Mxico City in terms of condensation rate. A simplified theoretical model based on a steady-state energy balance on a radiator-condenser was fitted, as a function of the ambient temperature, the relative humidity and the wind velocity. A glass sheet and aluminum sheet white-painted were used as samples over the outdoor experiments. A good correlation was obtained between the theoretical and experimental data. The experimental results show that there was condensation in 68% of the winter nights on both condensers. The total winter condensed mass was 2977 g/m2 and 2888 g/m2 on the glass sheet and aluminum sheet white-painted, respectively. Thus, the condensed mass on the glass was only 3% higher than that on the painted surface. The maximum nightly dew harvests occurred during December, which linearly reduced from 50 g/m2 night to 22 g/m2 night as the winter months went by. The condensation occurred from 1:00 a.m. to 9:00 a.m., with maximum condensation rates between 6:00 a.m. and 7:00 a.m. The dew harvest can provide a partial alternative to the winter water shortage in certain locations with similar climates to the winter in Mexico City, as long as pollution is not significant.

  14. Production of Chlorella biomass in different types of flat bioreactors in temperate zones

    Ramos de Ortega, A.; Roux, J.C.

    1986-01-01

    The influence of several variables on the growth rate of the green algae Chlorella pyrenoidosa Chick has been studied. The effects of changes in culture medium, temperature and light are reported. For the production of algae biomass, three different types of closed-culture systems or bioreactors were used (flexible sheath, translucent tubes and rigid panels, all of them in PVC) under different environmental conditions (chamber, greenhouse and outdoor culture). The results show that the growth of Chlorella is influenced by water quality. However, the algae have a good resistance to temperature variations and they can grow even under low light intensity conditions. Comparing the performance of different bioreactors, it was shown that the outdoor rigid panel system with integrated temperature regulation resulted in a biomass production similar to that for cultures grown in outdoor open ponds in regions with better climatic conditions. 15 references.

  15. Lithological controls on sandstone weathering: a proposal of morphofacies for the humid temperate zone of Europe

    Adamovič, Jiří; Mikuláš, Radek; Schweigstillová, Jana

    Dresden : Höhlen- und Karstforschung Dresden e. V, 2010 - (Simmert, H.). s. 26-28 [Symposium on Pseudokarst /11./. 12.05.2010-16.05.2010, Saupsdorf/Saxon Switzerland] R&D Projects: GA AV ČR IAA300130806 Institutional research plan: CEZ:AV0Z30130516 Keywords : sandstone * morphofaciel * lithology Subject RIV: DB - Geology ; Mineralogy

  16. Influence of the temperature and strain rate on the structure and fracture mode of high-strength steels upon the simulation of the thermal cycle of welding and post-welding tempering

    Pazilova, U. A.; Il'in, A. V.; Kruglova, A. A.; Motovilina, G. D.; Khlusova, E. I.

    2015-06-01

    Structural changes and the main features of the fracture of the base metal and the coarse-grained region of the heat-affected zone of the welded joints of high-strength steels have been studied by simulating the thermal cycle of welding and post-welding heat treatment. The effects of the simultaneous action of heating for high-temperature tempering and of deformation allowing the estimation of the impact of residual welding stresses have been studied. The probable reasons of the formation of cracks in welds upon the postwelding tempering have been determined.

  17. A checklist of the winter bird community in different habitat types of Rosekandy Tea Estate of Assam, India

    A. Ahmed

    2014-02-01

    Full Text Available This study was aimed at preparing an inventory of the avifauna and to document the species composition of birds during winter in different habitat types of Rosekandy Tea Estate of Cachar District of Assam. Four habitat types, viz., tea plantation, ecotone zone, secondary growth forest and water bodies were selected within the tea estate and surveyed from mid-December 2010 (early winter to mid-April 2011 (late winter covering four months of survey. A total of 88 species were recorded during the survey period with the highest number of species in ecotone zone (n=63, followed by secondary forest (n=60, tea plantation (n=48 and water bodies (n=17. The species were further categorized into different feeding and habitat guilds to study the distribution of bird species in different habitat types according to various guilds.

  18. The investigation of applicability of the Hollomon-Jaffe equation on tempering the HSLA steel

    Patarić, A.; Mihailović, M.; Z. Gulišija; Janjušević, Z.

    2009-01-01

    High strength low-alloyed (HSLA) Cr-Mn-Si steels belong to a group of steels that can reach their full mechanical properties after quenching and tempering. Those properties depend both on the temperature and time of tempering. Knowing the tempering parameters, it is possible to reach the desired properties of the treated steel. Some results on investigating the Hollomon-Jaffe equation (in parametric form) application for tempering of HSLA steel, are shown in this paper. The experiments were p...

  19. Temperate Ice Depth-Sounder: A proved concept for temperate ice sounding

    Jara-Olivares, V. A.; Rodriguez-Morales, F.; Leuschen, C.; Ayyangar, H.; Gogineni, P. S.

    2010-12-01

    Observations of glaciers and snow cover are important to the understanding and prediction of both ablation ratio and the overall impact reductions in ice formation will have on the cryosphere. The extent of the coverage of these observations still remains limited in some regions due to natural geographic accidents that make it problematic for human in-situ exploration. Instruments with the capability to estimate the composition and thickness of ice formations are a suitable compliment to enhance the quality and extent of the data currently available. Radar instruments can be used to provide information on the internal and basal conditions of ice masses. For temperate ice, the high water content produces volume scattering and attenuation in propagating radar waves. The volume scattering appears as clutter masking weak bedrock echoes. At the Center for Remote Sensing of Ice Sheets (CReSIS) we have developed an HF dual-frequency Temperate-Ice Depth Sounder radar (TIDSoR) for systematic surveys of the thickness and sub-glacial topography of temperate-ice. This radar has successfully sounded 1-km thick ice near Jakobshavn, Greenlad glacier and 2-km thick cold ice near Byrd camp, Antarctica. TIDSoR operates at two different center frequencies: 7.5 MHz and 14 MHz, with a maximum peak output power of 20 W. It also can be programmed to operate at other frequencies in the HF spectrum. The transmitted waveform is a digitally generated pulse with a programmable repetition frequency of up to 20 kHz. The frequencies of operation were selected based on three main criteria: (a) the ability to overcome volume scattering produced by the ice inclusions, such as water pockets, with at least 10 dB power of a backscattered signal and up to 3 km depth; (b) compatibility with high frequency aviation radio systems, which are mostly used for voice communications; and (c) portability, lower power consumption, and interface with a portable computer. The radar consists of three functional blocks: the digital section, the radio-frequency (RF) section, and the antenna. It is designed to weigh less than 2 kg, excluding the power supply. The digital section generates the transmit waveforms, as well as the timing and control signals. It also digitizes the output signal from the receiver and stores the data in binary format using a computer. The RF-section consists of a high-power transmitter and a low-noise receiver with variable gain (digitally controlled). In regards to the antenna, TIDSoR uses an electrically small 4-m dipole antenna and can operate in dual- or single-antenna configurations for surface-based and airborne platforms. In a single-antenna configuration, the radiating element can be time-shared between the transmitter and receiver by means of a transmit/receive switch. The radar antenna is currently being re-designed for installation on the tail boom of a P-3 Orion for airborne operation. In this configuration, TIDSoR could be supported by the aircraft power system. In this paper, we will discuss the status of the instrument and our most recent results from data collected in Greenland and Antarctica, showing successful sounding of ice up to 2-km thick. Finally, we will discuss the adaptation of this system for airborne operation.

  20. Temporal changes in the ectomycorrhizal community in two soil horizons of a temperate oak forest.

    Courty, Pierre-Emmanuel; Franc, Alain; Pierrat, Jean-Claude; Garbaye, Jean

    2008-09-01

    The species structure of an ectomycorrhizal (ECM) community was assessed monthly for 15 months in the two horizons (A1 and A2) of an oak temperate forest in northeastern France. Ectomycorrhizal species were identified each month by internal transcribed spacer sequencing. Seventy-five fungal symbionts were identified. The community was dominated by Tomentellaceae, Russulaceae, Cortinariaceae, and Boletales. Four species are abundant in the study site: Lactarius quietus, Tomentella sublilacina, Cenococcum geophilum, and Russula sp1. The relative abundance of each species varied depending on the soil horizon and over time. Some species, such as L. quietus, were present in the A1 and A2 horizons. C. geophilum was located particularly in the A2 horizon, whereas T. sublilacina was more abundant in A1. Some species, such as Clavulina sp., were detected in winter, while T. sublilacina and L. quietus were present all year long. Our results support the hypothesis that a rapid turnover of species composition of the ECM community occurs over the course of a month. The spatial and temporal unequal distribution of ECM species could be explained by their ecological preferences, driven by such factors as root longevity, competition for resources, and resistance to environmental variability. PMID:18658284

  1. Winter barley mutants created in the Ukraine

    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)

  2. Seasonal in situ observations of glyoxal and methylglyoxal over the temperate oceans of the Southern Hemisphere

    Lawson, S. J.; Selleck, P. W.; Galbally, I. E.; Keywood, M. D.; Harvey, M. J.; Lerot, C.; Helmig, D.; Ristovski, Z.

    2015-01-01

    The dicarbonyls glyoxal and methylglyoxal have been measured with 2,4-dinitrophenylhydrazine (2,4-DNPH) cartridges and high-performance liquid chromatography (HPLC), optimised for dicarbonyl detection, in clean marine air over the temperate Southern Hemisphere (SH) oceans. Measurements of a range of dicarbonyl precursors (volatile organic compounds, VOCs) were made in parallel. These are the first in situ measurements of glyoxal and methylglyoxal over the remote temperate oceans. Six 24 h samples were collected in summer (February-March) over the Chatham Rise in the south-west Pacific Ocean during the Surface Ocean Aerosol Production (SOAP) voyage in 2012, while 34 24 h samples were collected at Cape Grim Baseline Air Pollution Station in the late winter (August-September) of 2011. Average glyoxal mixing ratios in clean marine air were 7 ppt at Cape Grim and 23 ppt over Chatham Rise. Average methylglyoxal mixing ratios in clean marine air were 28 ppt at Cape Grim and 10 ppt over Chatham Rise. The mixing ratios of glyoxal at Cape Grim are the lowest observed over the remote oceans, while mixing ratios over Chatham Rise are in good agreement with other temperate and tropical observations, including concurrent Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations. Methylglyoxal mixing ratios at both sites are comparable to the only other marine methylglyoxal observations available over the tropical Northern Hemisphere (NH) ocean. Ratios of glyoxal : methylglyoxal > 1 over Chatham Rise but formation and/or loss processes or rates dominate at each site. Dicarbonyl precursor VOCs, including isoprene and monoterpenes, are used to calculate an upper-estimate yield of glyoxal and methylglyoxal in the remote marine boundary layer and explain at most 1-3 ppt of dicarbonyls observed, corresponding to 10% and 17% of the observed glyoxal and 29 and 10% of the methylglyoxal at Chatham Rise and Cape Grim, respectively, highlighting a significant but as yet unknown production mechanism. Surface-level glyoxal observations from both sites were converted to vertical columns and compared to average vertical column densities (VCDs) from GOME-2 satellite retrievals. Both satellite columns and in situ observations are higher in summer than winter; however, satellite vertical column densities exceeded the surface observations by more than 1.5 × 1014 molecules cm-2 at both sites. This discrepancy may be due to the incorrect assumption that all glyoxal observed by satellite is within the boundary layer, or it may be due to challenges retrieving low VCDs of glyoxal over the oceans due to interferences by liquid water absorption or the use of an inappropriate normalisation reference value in the retrieval algorithm. This study provides much-needed data to verify the presence of these short-lived gases over the remote ocean and provide further evidence of an as yet unidentified source of both glyoxal and also methylglyoxal over the remote oceans.

  3. Ecosystem respiration depends strongly on photosynthesis in a temperate heath

    Larsen, Klaus Steenberg; Ibrom, Andreas; Beier, Claus; Jonasson, S.; Michelsen, A.

    2007-01-01

    We measured net ecosystem CO2 flux (F-n) and ecosystem respiration (R-E), and estimated gross ecosystem photosynthesis (P-g) by difference, for two years in a temperate heath ecosystem using a chamber method. The exchange rates of carbon were high and of similar magnitude as for productive forest...

  4. Haloorganics in Temperate Forest Ecosystems: Sources, Transport and Degradation

    Clarke, N.; Gryndler, M; Liste, H. H.; Schroll, R.; Schrder, P.; Matucha, M. (Miroslav)

    2011-01-01

    A survey is given of processes of formation, transport and degradation of haloorganics in temperate and boreal forest, predominantly in Europe. More work is necessary in order to understand the environmental impact of haloorganics in temperature and boreal forest soils. This includes both further research, especially to undestand the key processes of formation and degradation of halogenated compounds.

  5. Tempered orbital energies and the potential curve within a molecule

    It is shown that the sum of the tempered orbital energies behaves much the same way as does the some of the Hartree--Fock orbital energies. The H2 moluecule in its minimum basis set description is chosen as an example and comparison of orbital energies is carried out

  6. Microstructure properties of tempered D6ac steel

    Highlights: ► We evaluated microstructure properties of tempered D6ac steel. ► The forming process has a high microhardness of martensite phase at surface layer. ► XRD spectra observed that the residual austenite and/or mixed structures of ferrite with the precipitation of carbides. ► 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 °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.

  7. Parallel tempering and decorrelation of topological charge in full QCD

    Ilgenfritz, E. -M.; Kerler, W.; M. Müller-Preussker(Humboldt U.Berlin); Stüben, H.

    2000-01-01

    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.

  8. Joints in Tempered Glass Using Glass Dowel Discs

    Nielsen, Jens Henrik; Poulsen, Peter Noe

    transparency of the glass. This is achieved by using a dowel disc made entirely of tempered glass. The concept of the joint is proved by pilot tests and numerical models. From the work it is seen that the load-carrying capacity of such a connection is similar to what is found for traditionally in-plane loaded...

  9. Tempered fractional time series model for turbulence in geophysical flows

    We propose a new time series model for velocity data in turbulent flows. The new model employs tempered fractional calculus to extend the classical 5/3 spectral model of Kolmogorov. Application to wind speed and water velocity in a large lake are presented, to demonstrate the practical utility of the model. (paper)

  10. Groundwater flow modelling of periods with temperate climate conditions - Forsmark

    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

    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

  11. Groundwater flow modelling of periods with temperate climate conditions - Forsmark

    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

  12. Payment mechanisms for winter road maintenance services

    Adel Abdi

    2013-12-01

    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.

  13. Shifts of climate zones in multi-model climate change experiments using the Koeppen climate classification

    Hanf, Franziska; Koerper, Janina; Spangehl, Thomas; Cubash, Ulrich [Freie Univ. Berlin (Germany). Inst. fuer Meteorologie

    2012-04-15

    This study investigates the future changes in the climate zones' distribution of the Earth's land area due to increasing atmospheric greenhouse gas concentrations in three IPCC SRES emissions scenarios (A1B, A2 and B1). The Koeppen climate classification is applied to climate simulations of seven atmosphere-ocean general circulation models (AOGCMs) and their multi-model mean. The evaluation of the skill of the individual climate models compared to an observation-reanalysis-based climate classification provides a first order estimate of relevant model uncertainties and serves as assessment for the confidence in the scenario projections. Uncertainties related to differences in simulation pathways of the future projections are estimated by both, the multi-model ensemble spread of the climate change signals for a given scenario and differences between different scenarios. For the recent climate the individual models fail to capture the exact Koeppen climate types in about 24-39 % of the global land area excluding Antarctica due to temperature and precipitation biases, while the multi-model ensemble mean simulates the present day observation-reanalysis-based distribution of the climate types more accurately. For the end of the 21{sup st} century compared to the present day climate the patterns of change are similar across the three scenarios, while the magnitude of change is largest for the highest emission scenario. Moreover, the temporal development of the climate shifts from the end of the 20st century and during the 21{sup st} century show that changes of the multi-model ensemble mean for the A2 and B1 scenario are generally within the ensemble spread of the individual models for the A1B scenario, illustrating that for the given range of scenarios the model uncertainty is even larger than the spread given by the different GHG concentration pathways. The multi-model ensemble mean's projections show climate shifts to dryer climates in the subtropics (Australia, Mediterranean Basin, southern Africa). This is consistent with an increase of area classified as Tropical Savanna Climate as well as Dry Climates. Furthermore, there is a poleward extension of the warmer climate types in the northern hemisphere causing a retreat of regions with Cold Climate with Moist Winter and Tundra Climate. The European region shows largest changes comparing the shifts in the different continents (37.1 % of the European land area) as a result of a large extension of the Humid Temperate Climate across eastern and north-eastern Europe at the cost of the Cold Climate with Moist Winter. (orig.)

  14. The engineering approach to winter sports

    Cheli, Federico; Maldifassi, Stefano; Melzi, Stefano; Sabbioni, Edoardo

    2016-01-01

    The Engineering Approach to Winter Sports presents the state-of-the-art research in the field of winter sports in a harmonized and comprehensive way for a diverse audience of engineers, equipment and facilities designers, and materials scientists. The book examines the physics and chemistry of snow and ice with particular focus on the interaction (friction) between sports equipment and snow/ice, how it is influenced by environmental factors, such as temperature and pressure, as well as by contaminants and how it can be modified through the use of ski waxes or the microtextures of blades or ski soles. The authors also cover, in turn, the different disciplines in winter sports:  skiing (both alpine and cross country), skating and jumping, bob sledding and skeleton, hockey and curling, with attention given to both equipment design and on the simulation of gesture and  track optimization.

  15. [Treatment of winter diseases in summer].

    Gao, Zhi-Ping

    2014-04-01

    To explore the connotation and essence of treatment of winter diseases in summer with analysis and deduction. Treating winter diseases in summer is the concrete embodiment and application of taking advantage of "recuperating yang in spring and summer". Winter diseases are formed by compound factors with deficiency of yangqi as the prerequisite and yin as well as cold as the predominant pathogens. Its pathological characteristic rests with stagnation in meri-dians and collaterals. Aiming at curing chronic diseases, reinforcing yangqi and removing stagnation in meridians and collaterals, treatment in summer is a treating strategy focused on proper opportunity of treatment, which is expected to yield twice the result with half the effort. To select the suitable indications is taken as the core of this treating strategy. And at the same time, blind expansion without careful consideration is not suggested. PMID:24946652

  16. Hatchling turtles survive freezing during winter hibernation.

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

    1988-01-01

    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 ...

  17. Implanting radio transmitters in wintering canvasbacks

    Olsen, G.H.; Dein, F.J.; Haramis, G.M.; Jorde, D.G.

    1992-01-01

    To conduct telemetry studies of wintering canvasbacks (Aythya valisineria) on Chesapeake Bay, we needed to devise a suitable method of radio transmitter attachment. We describe an aseptic, intra-abdominal surgical technique, using the inhalation anesthetic isoflurane, to implant 20-g radio transmitters in free-ranging canvasbacks. We evaluated the technique over 3 winters (1987-89), when an annual average of 83 female canvasbacks received implant surgery during a 9-day period in mid-December. Of 253 ducks, 248 (98%) were implanted successfully, and 200 (80.6%) completed the 70-day study until early March. No mortality or abnormal behavior from surgery was identified post-release.

  18. Nuclear winter: The evidence and the risks

    Greene, O.

    1985-01-01

    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.

  19. Nuclear winter: The evidence and the risks

    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

  20. Camellia spp. : Kamelien (Theaceae), Rosen des Winters

    Dörken, Veit Martin; Jagel, Armin

    2012-01-01

    Kamelien haben ausgesprochen attraktive Blüten und blühen im Winter, weswegen man sie auch "Rosen des Winters" nennt. Bei den Kamelien, die bei uns im Gartenhandel angeboten werden, handelt es sich in den meisten Fällen um Sorten der Japanischen Kamelie (Camellia japonica). In Ostasien fand die Art in der Gartenkultur als Blütensolitär schon sehr lange Verwendung, bevor sie Anfang des 18. Jahrhunderts auch nach Europa gelangte. In den letzten Jahren werden Kamelien zunehmend auch in deutschen...

  1. Effect of normalizing and tempering temperatures on microstructure and mechanical properties of P92 steel

    In the present investigation, systematic studies on microstructure and mechanical properties of P92 steel subjected to various normalizing (1313–1353 K) and tempering (1013–1053 K) temperatures were carried out. The effect of heat treatment on microstructural parameters revealed an increase in grain size, lath width and decrease in the area fraction of the precipitates with an increase in normalizing temperature. The precipitate size has not changed significantly with increase in the normalizing temperature; rather it increased with increase in tempering temperature. Activation energy calculations confirmed the two fold mechanisms that dominate the tempering behavior. As a consequence, yield stress (YS) and ultimate tensile strength (UTS) were found to change with normalizing and tempering temperatures. P92 steel normalized at 1353 K and tempered at 1013 K was found to have the best combination of strength and ductility. - Highlights: • P92 steel subjected to normalizing (1313–1353 K) and tempering (1013–1053 K) temperatures. • YS, UTS and hardness increased with normalizing and decreased with tempering temperatures. • Precipitate size, lath width increased with increase in tempering temperature. • Ductility increased with normalizing and tempering temperatures with a plateau at 1033 K. • Activation energy calculations confirmed two fold mechanism for tempering behavior. • Normalizing at 1353 K and tempering at 1013 K, optimum combination for ASME P92 steel

  2. Effect of tempering temperature on the stress rupture properties of Grade 92 steel

    P92 steel is used in normalized and tempered condition for optimal creep properties. Effect of varying tempering temperatures in the range of 740–780 °C on the stress rupture properties has been investigated in this study. High dislocation density and fine laths resulted in high rate of microstructural evolution in 740 °C tempering case, hence the steep slope of rupture curve was observed as compared to higher tempering temperatures. Quantification of lath width and precipitate size under Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed increase in lath width and precipitate coarsening with tempering temperature and exposure time. Increase in lath width was more pronounced in 740 °C tempering case. The results were supported by the damage parameter (λ) and hardness measurements. Variation in fractographic features was associated more with rupture time, for a particular tempering temperature. Coarser precipitates were responsible for cavity initiation, inducing some brittle fracture at higher rupture times

  3. Bacterial Diversity in the South Adriatic Sea during a Strong, Deep Winter Convection Year

    Korlevi?, M.; Pop Ristova, P.; Gari?, R.; Amann, R.

    2014-01-01

    The South Adriatic Sea is the deepest part of the Adriatic Sea and represents a key area for both the Adriatic Sea and the deep eastern Mediterranean. It has a role in dense water formation for the eastern Mediterranean deep circulation cell, and it represents an entry point for water masses originating from the Ionian Sea. The biodiversity and seasonality of bacterial picoplankton before, during, and after deep winter convection in the oligotrophic South Adriatic waters were assessed by combining comparative 16S rRNA sequence analysis and catalyzed reporter deposition-fluorescence in situ hybridization (CARD-FISH). The picoplankton communities reached their maximum abundance in the spring euphotic zone when the maximum value of the chlorophyll a in response to deep winter convection was recorded. The communities were dominated by Bacteria, while Archaea were a minor constituent. A seasonality of bacterial richness and diversity was observed, with minimum values occurring during the winter convection and spring postconvection periods and maximum values occurring under summer stratified conditions. The SAR11 clade was the main constituent of the bacterial communities and reached the maximum abundance in the euphotic zone in spring after the convection episode. Cyanobacteria were the second most abundant group, and their abundance strongly depended on the convection event, when minimal cyanobacterial abundance was observed. In spring and autumn, the euphotic zone was characterized by Bacteroidetes and Gammaproteobacteria. Bacteroidetes clades NS2b, NS4, and NS5 and the gammaproteobacterial SAR86 clade were detected to co-occur with phytoplankton blooms. The SAR324, SAR202, and SAR406 clades were present in the deep layer, exhibiting different seasonal variations in abundance. Overall, our data demonstrate that the abundances of particular bacterial clades and the overall bacterial richness and diversity are greatly impacted by strong winter convection. PMID:25548042

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

    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. (author)

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

    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

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

    Tang, Linghui; Hammoudeh, Shawkat [Department of Economics and International Business, Lebow College of Business, Drexel University, 19104 Philadelphia, PA (United States)

    2002-11-01

    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.

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

    Linghui Tang; Shawkat Hammoudeh [Drexel University, Philadelphia, PA (United States). Lebow College of Business

    2002-11-01

    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. (author)

  8. 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

    Mario Mellado Z.

    2001-04-01

    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.

  9. 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

    I. Vitela

    2005-01-01

    Full Text Available 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.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 Aguascalientes. 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.

  10. Observations on the biology, epidemiology and economic relevance of rumen flukes (Paramphistomidae) in cattle kept in a temperate environment.

    Sargison, Neil; Francis, Emily; Davison, Chloe; Bronsvoort, Barend M deC; Handel, Ian; Mazeri, Stella

    2016-03-30

    There is concern about the probable recent introduction, increased prevalence and potential economic impact of rumen fluke infection of United Kingdom cattle. A study of 339 cattle slaughtered in a Scottish red meat abattoir was undertaken with the aims of describing the prevalence and geographical distribution of rumen fluke infection, estimating its effect on production, and evaluating faecal egg counts (FECs) as a tool to diagnose infection in live animals and study the epidemiology of the disease. The overall proportion of cattle consigned to the abattoir from northern United Kingdom with rumen fluke infection in the forestomachs was 0.29. Rumen flukes were distributed predominantly in the cranial sac of the rumen and adjacent to the reticular groove. Overall, a mean of 213 and median of 44 rumen flukes was identified in the forestomachs of rumen fluke-positive cattle. The mean and median FECs of animals were 26.01 and 5.20 eggs per gram (epg), respectively. There was a significant difference between the mean FECs per rumen fluke of 0.08 and 0.13epg during summer/autumn and winter sampling periods, respectively. The overall correlation between rumen fluke FECs and the number of flukes in the forestomach was high, albeit lower in the summer/autumn than in the winter period. The sensitivities of rumen fluke FECs for the identification of flukes in the forestomach during the summer/autumn and winter sampling periods were 0.65 and 0.85, respectively. These results will aid in the interpretation of rumen fluke FECs when monitoring cattle health and production and studying the parasite's epidemiology in a temperate environment, thereby informing rational, precise and sustainable disease control. PMID:26921033

  11. Effect of environmental factors on the relationship between concentrations of coprostanol and fecal indicator bacteria in tropical (Mekong Delta) and temperate (Tokyo) freshwaters.

    Isobe, Kei O; Tarao, Mitsunori; Chiem, Nguyen H; Minh, Le Y; Takada, Hideshige

    2004-02-01

    A reliable assessment of microbial indicators of fecal pollution (total coliform, Escherichia coli, and fecal streptococcus) is critical in tropical environments. Therefore, we investigated the relationship between concentrations of indicator bacteria and a chemical indicator, coprostanol (5beta-cholestan-3beta-ol), in tropical and temperate regions. Water samples were collected from the Mekong Delta, Vietnam, during wet and dry seasons, and from Tokyo, Japan, during summer, the aftermath of a typhoon, and winter. During the wet season in the Mekong Delta, higher bacterial densities were observed in rivers, probably due to the higher bacterial inputs from soil particles with runoff. In Tokyo, higher bacterial densities were usually observed during summer, followed by those in the typhoon aftermath and winter. A strong logarithmic correlation between the concentrations of E. coli and coprostanol was demonstrated in all surveys. Distinctive seasonal fluctuations were observed, as concentrations of coprostanol corresponding to 1,000 CFU of E. coli/100 ml were at their lowest during the wet season in the Mekong Delta and the typhoon aftermath in Tokyo (30 ng/liter), followed by the dry season in the Mekong Delta and the summer in Tokyo (100 ng/liter), and they were much higher during the winter in Tokyo (400 ng/liter). These results suggested that E. coli is a specific indicator of fecal contamination in both tropical and temperate regions but that the densities are affected by elevated water temperature and input from runoff of soil particles. The concurrent determination of E. coli and coprostanol concentrations could provide a possible approach to assessing the reliability of fecal pollution monitoring data. PMID:14766559

  12. Regional greenhouse gas emissions from cultivation of winter wheat and winter rapeseed for biofuels in Denmark

    Elsgaard, Lars; Olesen, Jørgen E; Hermansen, John Erik; Kristensen, Inge Toft; Børgesen, Christen Duus

    2013-01-01

    equivalents (CO2eq) were quantified from the footprints of CO2, CH4 and N2O associated with cultivation and the emissions were allocated between biofuel energy and co-products. Greenhouse gas emission at the national level (Denmark) was estimated to 22.1 g CO2eq MJ−1 ethanol for winter wheat and 26.0 g CO2eq...... such regional factors as soil conditions, climate and input of agrochemicals. Here we analysed at a regional scale the greenhouse gas (GHG) emissions associated with cultivation of winter wheat for bioethanol and winter rapeseed for rapeseed methyl ester (RME) under Danish conditions. Emitted CO2...

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

    Rastad, Cecilia

    2009-01-01

    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, lowered...

  14. Stay Safe and Healthy This Winter!

    2010-11-23

    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 Women’s Health.   Date Released: 11/23/2010.

  15. Winter cooling in the northern Arabian Sea

    PrasannaKumar, S.; Prasad, T.G.

    forcing that leads to the observed high productivity during winter in the northern Arabian Sea. The weak northerly winds and increased solar insolation during the inter-monsoon period, led to the development of a highly stratified upper layer with warm sea...

  16. Resonance asymptotics in the generalized Winter model

    Exner, Pavel; Fraas, Martin

    2006-01-01

    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.

  17. Registration of Anton Hard White Winter Wheat

    ‘Anton’ (Reg. No. CV PI 651043) hard white winter wheat (Triticum aestivum L.) was developed by the USDA-ARS and the Nebraska Agricultural Experiment Station and released in December, 2007. "Anton" was selected from the cross WA691213-27/N86L177//‘Platte’. Anton primarily was released for its lo...

  18. Music Activities for Lemonade in Winter

    Cardany, Audrey Berger

    2014-01-01

    "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…

  19. The median winter snowline in the Alps

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

    2011-06-15

    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.)

  20. Come back on the french gas winter

    The document analyzes the french gas market behavior during the winter 2005/2006: the gas consumption, the imports decrease was offset by the the liquefied natural gas supply increase at Fos, the stocks levels and the transparency of the information. (A.L.B.)

  1. REGISTRATION OF 'NE422T' WINTER TRITICALE

    NE422T triticale (X.Triticosecale rimpaui Wittm.) was developed cooperatively by the Nebraska Agricultural Experiment Station and the USDA-ARS. NE422T is an F3-derived F4 line that was released primarily for its superior forage production in rainfed winter cereal production systems in the central G...

  2. Winter in Northern Europe (WINE) Project

    Vonzahn, U.

    1982-01-01

    The scientific aims, work plan, and organization of the Middle Atmosphere Program winter in northern Europe (MAP/WINE) are described. Proposed contributions to the MAP/WINE program from various countries are enumerated. Specific atmospheric parameters to be examined are listed along with the corresponding measurement technique.

  3. Successful wrestle with winter in Bohunice NPP

    In this paper the operation on the Bohunice NPP during this winter period is presented. In January 9, 2005 formation of frost on the transformers during shut-down of the turbine of the Bohunice NPP as well defrosting are described

  4. Variation In Winter Hardiness Among Safflower Accessions

    Fall planted safflower (Carthamus tinctorius L.) would provide management alternatives in crop rotations and potentially increase yield. Our objective was to relate several fall growth factors to winter survival in a diverse set of 11 safflower accessions grown at Central Ferry and Pullman WA, USA....

  5. Appalachia's Winter Secret: Downhill on the Mountains.

    Johnson, Randy

    1991-01-01

    Describes ski-industry and winter-tourism growth in Appalachia. Sketches ski-resort developments in Maryland, Pennsylvania, North Carolina, and West Virginia. Describes economic threats to industry, its economic impact on Appalachian states and region, resorts' general qualities, and ski industry's promotional efforts. (TES)

  6. IMPACT OF OZONE ON WINTER WHEAT YIELD

    Wheat is one of the more important agricultural crops in the USA, and the major production areas may be subjected to potentially damaging concentrations of ozone (O3). Since no information was available regarding the O3 sensitivity of winter wheat cultivars grown in the Midwest, ...

  7. Numerical simulation of a rare winter hailstorm event over Delhi, India on 17 January 2013

    Chevuturi, A.

    2014-12-19

    This study analyzes the cause of the rare occurrence of a winter hailstorm over New Delhi/NCR (National Capital Region), India. The absence of increased surface temperature or low level of moisture incursion during winter cannot generate the deep convection required for sustaining a hailstorm. Consequently, NCR shows very few cases of hailstorms in the months of December-January-February, making the winter hail formation a question of interest. For this study, a recent winter hailstorm event on 17 January 2013 (16:00–18:00 UTC) occurring over NCR is investigated. The storm is simulated using the Weather Research and Forecasting (WRF) model with the Goddard Cumulus Ensemble (GCE) microphysics scheme with two different options: hail and graupel. The aim of the study is to understand and describe the cause of hailstorm event during over NCR with a comparative analysis of the two options of GCE microphysics. Upon evaluating the model simulations, it is observed that the hail option shows a more similar precipitation intensity with the Tropical Rainfall Measuring Mission (TRMM) observation than the graupel option does, and it is able to simulate hail precipitation. Using the model-simulated output with the hail option; detailed investigation on understanding the dynamics of hailstorm is performed. The analysis based on a numerical simulation suggests that the deep instability in the atmospheric column led to the formation of hailstones as the cloud formation reached up to the glaciated zone promoting ice nucleation. In winters, such instability conditions rarely form due to low level available potential energy and moisture incursion along with upper level baroclinic instability due to the presence of a western disturbance (WD). Such rare positioning is found to be lowering the tropopause with increased temperature gradient, leading to winter hailstorm formation.

  8. Numerical simulation of a rare winter hailstorm event over Delhi, India on 17 January 2013

    Chevuturi, A.; Dimri, A. P.; Gunturu, U. B.

    2014-12-01

    This study analyzes the cause of the rare occurrence of a winter hailstorm over New Delhi/NCR (National Capital Region), India. The absence of increased surface temperature or low level of moisture incursion during winter cannot generate the deep convection required for sustaining a hailstorm. Consequently, NCR shows very few cases of hailstorms in the months of December-January-February, making the winter hail formation a question of interest. For this study, a recent winter hailstorm event on 17 January 2013 (16:00-18:00 UTC) occurring over NCR is investigated. The storm is simulated using the Weather Research and Forecasting (WRF) model with the Goddard Cumulus Ensemble (GCE) microphysics scheme with two different options: hail and graupel. The aim of the study is to understand and describe the cause of hailstorm event during over NCR with a comparative analysis of the two options of GCE microphysics. Upon evaluating the model simulations, it is observed that the hail option shows a more similar precipitation intensity with the Tropical Rainfall Measuring Mission (TRMM) observation than the graupel option does, and it is able to simulate hail precipitation. Using the model-simulated output with the hail option; detailed investigation on understanding the dynamics of hailstorm is performed. The analysis based on a numerical simulation suggests that the deep instability in the atmospheric column led to the formation of hailstones as the cloud formation reached up to the glaciated zone promoting ice nucleation. In winters, such instability conditions rarely form due to low level available potential energy and moisture incursion along with upper level baroclinic instability due to the presence of a western disturbance (WD). Such rare positioning is found to be lowering the tropopause with increased temperature gradient, leading to winter hailstorm formation.

  9. Type 1,1-operators on spaces of temperate distributions

    Johnsen, Jon

    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 spaces, and more generally in Besov and Lizorkin–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 Littlewood–Paley analysis the well-known paradifferential decomposition is also derived for...

  10. Geometric Brownian Motion with Tempered Stable Waiting Times

    Gajda, Janusz; Wyłomańska, Agnieszka

    2012-08-01

    One of the earliest system that was used to asset prices description is Black-Scholes model. It is based on geometric Brownian motion and was used as a tool for pricing various financial instruments. However, when it comes to data description, geometric Brownian motion is not capable to capture many properties of present financial markets. One can name here for instance periods of constant values. Therefore we propose an alternative approach based on subordinated tempered stable geometric Brownian motion which is a combination of the popular geometric Brownian motion and inverse tempered stable subordinator. In this paper we introduce the mentioned process and present its main properties. We propose also the estimation procedure and calibrate the analyzed system to real data.

  11. Effect of tempering on corrosion resistance of cast aluminium bronzes

    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

  12. Reversible temper brittleness on tensile tests at room temperature

    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 500C in a 48 hour heat treatment at 5000C. 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

  13. Zone distillation: justification

    The features of zone distillation (with zone melting of refined material and with pulling of condensate) as a new purification method are shown. The method is based on similarity of equations of distillation and crystallization refining. The analogy between some distillation and condensation methods (particularly between zone distillation and zone re-crystallization) is should up

  14. Impact of warm winters on microbial growth

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

    2014-05-01

    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.

  15. Environmental Controls and Management Effects on Ecosystem Carbon Exchange in Two Grazed Temperate Grasslands

    Ni Choncubhair, O.; Humphreys, J.; Lanigan, G.

    2013-12-01

    Temperate grasslands constitute over 30% of the Earth's naturally-occurring biomes and make an important contribution towards the partial mitigation of anthropogenic greenhouse gas emissions by terrestrial ecosystems. Accumulation of carbon (C) in grassland systems predominantly takes place in below-ground repositories, enhanced by the presence of a stable soil environment with low carbon turnover rates, active rhizodeposition and high levels of residue and organic inputs. However, this C sequestration is strongly influenced by soil characteristics and climatic variables. Furthermore, in managed pasture systems, carbon exchange across the soil-atmosphere boundary is additionally affected by management activities, such as biomass removal, grazing events and the deposition or application of organic amendments. These biotic and abiotic factors contribute greatly towards the large uncertainty associated with the carbon balance of grassland ecosystems and demand further analysis. In the present study, the controls and drivers of carbon dynamics in two rotationally-grazed grasslands in Ireland were examined. The sites experience similar temperate climatic regimes but differ in soil texture classification and stocking rate. Eddy covariance measurements of net ecosystem exchange of carbon were complemented by regular assessment of standing biomass, leaf cover, harvest exports and organic amendment inputs. Our study showed that mild weather conditions and an extended growing season sustained net C accumulation at both sites for at least ten months of the year. Despite differing soil drainage characteristics, winter fluxes of net carbon exchange and its component fluxes, gross photosynthesis and ecosystem respiration, were highly comparable between the two sites. Management practices during the active growing season exerted a strong influence on both the direction and the rate of C exchange in the grassland systems, with a strong dependence, however, on the timing and intensity of the management effect. Harvest-induced reductions in productivity and net C uptake were generally greater than grazing-induced shifts, however the effects were at times mediated by environmental conditions. Our research highlighted the complex nature of the investigated grasslands resulting from the heterogeneous footprint induced by rotational grazing, grass harvesting and intensive management practices. Further work will focus on the applicability of different gap-filling methodologies for capturing the temporal and spatial variability observed. The potential of vegetation indices as a means of tracking sward development will also be investigated, with the aim of improving our understanding of the impact of vegetation dynamics on measured ecosystem carbon fluxes.

  16. Neopaleozoic flora in stratigraphic zones of Gondwana

    Archangelsky, S.

    1984-01-01

    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.

  17. Restoration of a temperate reef: Effects on the fish community

    Støttrup, Josianne; Stenberg, Claus; Dahl, Karsten; Kristensen, Louise Dahl; Richardson, Katherine

    2014-01-01

    The extraction of large boulders from coastal reefs for construction of harbours and coastal protection has led to habitat degradation for local fish populations through the destruction of cavernous reefs and changes in macroalgal cover resulting from a loss of substrate. The temperate reef at Læsø...... findings highlight the importance of reef habitats for fish communities and the need for their protection...

  18. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    Joyce, Steven; Simpson, Trevor; Hartley, Lee; Applegate, David; Hoek, Jaap; Jackson, Peter; Roberts, David; Swan, David (Serco Technical Consulting Services (United Kingdom)); Gylling, Bjoern; Marsic, Niko (Kemakta Konsult AB, Stockholm (Sweden)); Rhen, Ingvar (SWECO Environment AB, Falun (Sweden))

    2010-12-15

    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 hydraulic 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 Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. 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 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 a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) 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 up until the receding shoreline leaves the modelling domain at around 15,000 AD. 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

  19. Species diversity of Lachnum (Helotiales, Hyaloscyphaceae) from temperate China*

    Ye, Ming; Cao, Shu-qing; Jiang, Shao-tong; Pan, Li-jun; Luo, Shui-zhong; Li, Xing-jiang

    2005-01-01

    Twenty-three temperate China species of Lachnum, Lachnum abnorme, L. angustum, L. brevipilosum, L. calosporum, L. calyculiforme, L. carneolum, L. ciliare, L. controversum, L. flavidulum, L. cf. fushanese, L. indicum, L. kumaonicum, L. lushanese, L. minutum, L. montanum, L. cf. pteridophyllum, L. pygmaeum, L. sclerotii var. sclerotii, L. sclerotii var. sichuanense, L. subpygmeaum, L. tenuissimum, L. virgineum and L. willisii are reported, whose main characteristics are given in a formula of th...

  20. Radioecology of temperate coastal sand dunes: A synthesis

    Wood, M.D.; Beresford, N. A.; Barnett, C.L.; Copplestone, D.

    2011-01-01

    Temperate coastal sand dunes are amongst the most dynamic landscapes on earth, their evolution being mediated by both climatic and environmental conditions. Formed at the interface between terrestrial and aquatic environments, these biodiversity-rich ecosystems are a valuable resource that deliver a range ecosystem services (the benefits people derive from ecosystems). Sand dune ecosystem services include agricultural products, storm protection through coastal defence, river water purificat...

  1. Efficient assignment of the temperature set for Parallel Tempering

    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.

  2. Optimal Allocation of Replicas to Processors in Parallel Tempering Simulations

    Earl, David J.; Deem, Michael W

    2004-01-01

    The optimal allocation of replicas to a homogeneous or heterogenous set of processors is derived for parallel tempering simulations on multi-processor machines. In the general case, it is possible without substantially increasing wall clock time to achieve nearly perfect utilization of CPU time. Random fluctuations in the execution times of each of the replicas do not significantly degrade the performance of the scheduler.

  3. Parallel Tempering Algorithm for Conformational Studies of Biological Molecules

    Hansmann, Ulrich H. E.

    1997-01-01

    The effectiveness of a new algorithm, parallel tempering, is studied for numerical simulations of biological molecules. These molecules suffer from a rough energy landscape. The resulting slowing down in numerical simulations is overcome by the new method. This is demonstrated by performing simulations with high statistics for one of the simplest peptides, Met-enkephalin. The numerical effectiveness of the new technique was found to be much better than traditional methods and is comparable to...

  4. Forgetting the starting distribution in finite interacting tempering

    Barta, Winfried

    2014-01-01

    Markov chain Monte Carlo (MCMC) methods are frequently used to approximately simulate high-dimensional, multimodal probability distributions. In adaptive MCMC methods, the transition kernel is changed "on the fly" in the hope to speed up convergence. We study interacting tempering, an adaptive MCMC algorithm based on interacting Markov chains, that can be seen as a simplified version of the equi-energy sampler. Using a coupling argument, we show that under easy to verify assumptions on the ta...

  5. Database Temperate Deciduous and Coniferous Forests of the Solling Hills

    Dölle, Michaela; Schmidt, Wolfgang; Parth, Andreas

    2012-01-01

    The Database Temperate Deciduous and Coniferous Forests of the Solling Hills (GIVD ID EU-DE-017) offers forest vegetation relevés obtained from different research projects during four decades in the Solling Hills (Lower Saxony, Germany). It contains relevés mainly of pure beech stands (Fagus sylvatica, Luzulo-Fagetum) representing the potential natural vegetation on acidic soils of the Solling Hills. Many parts of the Solling Hills have been converted into spruce monoculture stands (...

  6. Groundwater flow modelling of periods with temperate climate conditions - Laxemar

    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 hydraulic 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 Laxemar-Simpevarp site during temperate climate conditions as a comparison to corresponding modelling carried out for Forsmark /Joyce et al. 2010/. 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 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 a discrete fracture network (DFN) and equivalent continuous porous medium (ECPM) 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 up until the receding shoreline leaves the modelling domain at around 15,000 AD. 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

  7. First description of underwater acoustic diversity in three temperate ponds

    Rybak, Fanny; Depraetere, Marion; Gasc, Amandine; Le Viol, Isabelle; Pavoine, Sandrine; Sueur, Jrme

    2015-01-01

    The past decade has produced an increased ecological interest in sonic environments, or soundscapes. However, despite this rise in interest and technological improvements that allow for long-term acoustic surveys in various environments, some habitats soundscapes remain to be explored. Ponds, and more generally freshwater habitats, are one of these acoustically unexplored environments. Here we undertook the first long term acoustic monitoring of three temperate ponds in France. By aural and visual inspection of a selection of recordings, we identified 48 different sound types, and according to the rarefaction curves we calculated, more sound types are likely present in one of the three ponds. The richness of sound types varied significantly across ponds. Surprisingly, there was no pond-to-pond daily consistency of sound type richness variation; each pond had its own daily patterns of activity. We also explored the possibility of using six acoustic diversity indices to conduct rapid biodiversity assessments in temperate ponds. We found that all indices were sensitive to the background noise as estimated through correlations with the signal-to-noise ratio (SNR). However, we determined that the AR index could be a good candidate to measure acoustic diversities using partial correlations with the SNR as a control variable. Yet, research is still required to automatically compute the SNR in order to apply this index on a large data set of recordings. The results showed that these three temperate ponds host a high level of acoustic diversity in which the soundscapes were variable not only between but also within the ponds. The sources producing this diversity of sounds and the drivers of difference in daily song type richness variation both require further investigation. Such research would yield insights into the biodiversity and ecology of temperate ponds. PMID:26587351

  8. Nuclear Winter: The implications for civil defense

    ''Nuclear Winter'' is the term given to hypothesized cooling in the northern hemisphere following a nuclear war due to injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the original paper in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. The widespread use of 3-dimensional global circulation models have resulted in reduced estimates of cooling; 15 to 250C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought are likely to be direct threats to human survival for populations with the wherewithal to survive normal January temperatures; The principal threat from nuclear winter is to food production, and could present problems to third parties without food reserves; and Loss of a crop year is neither a new nor unexpected threat from nuclear war to the US and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the US due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year. 6 refs

  9. Nuclear Winter: The implications for civil defense

    Chester, C.V.; Perry, A.M.; Hobbs, B.F.

    1987-01-01

    ''Nuclear Winter'' is the term given to hypothesized cooling in the northern hemisphere following a nuclear war due to injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the original paper in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. The widespread use of 3-dimensional global circulation models have resulted in reduced estimates of cooling; 15 to 25/sup 0/C for a summer war and a few degrees for a winter war. More serious may be the possibility of suppression of convective precipitation by the altered temperature profiles in the atmosphere. However, very large uncertainties remain in input parameters, the models, and the results of calculations. We believe the state of knowledge about nuclear winter is sufficiently developed to conclude: Neither cold nor drought are likely to be direct threats to human survival for populations with the wherewithal to survive normal January temperatures; The principal threat from nuclear winter is to food production, and could present problems to third parties without food reserves; and Loss of a crop year is neither a new nor unexpected threat from nuclear war to the US and the Soviet Union. Both have at least a year's food reserve at all times. Both face formidable organizational problems in distributing their reserves in a war-damaged environment. The consequences of nuclear winter could be expected to fall more heavily on the Soviet Union than the US due to its higher latitude and less productive agriculture. This may be especially true if disturbances of rainfall amounts and distribution persist for more than a year. 6 refs.

  10. Radiation protection zoning

    Radiation being not visible, the zoning of an area containing radioactive sources is important in terms of safety. Concerning radiation protection, 2 work zones are defined by regulations: the monitored zone and the controlled zone. The ministerial order of 15 may 2006 settles the frontier between the 2 zones in terms of radiation dose rates, the rules for access and the safety standards in both zones. Radioprotection rules and the name of the person responsible for radiation protection must be displayed. The frontier between the 2 zones must be materialized and marked with adequate equipment (specific danger signs and tapes). Both zones are submitted to selective entrance, the access for the controlled zone is limited because of the radiation risk and of the necessity of confining radioactive contamination while the limitation of the access to the monitored zone is due to radiation risk only. (A.C.)

  11. Metallurgical interpretation of the change of notched bar impact strength in the heat-affected zone of weldable structural steels

    Notched bar impact energy in the heat-affected zone of joint welds of the steels StE 36, StE 51 and 20 MnMoNi55. Manual arc welding and submerged arc welding with heat input between 10,000 and 35,000 J/cm, stress relieving between 530 and 6000C. Significance of the structure in the heat-affected zone, the effect of heat treatment, the precipitation processes and of temper embrittlement. (orig.)

  12. Comparative genomic analysis of ten Streptococcus pneumoniae temperate bacteriophages.

    Romero, Patricia; Croucher, Nicholas J; Hiller, N Luisa; Hu, Fen Z; Ehrlich, Garth D; Bentley, Stephen D; Garca, Ernesto; Mitchell, Tim J

    2009-08-01

    Streptococcus pneumoniae is an important human pathogen that often carries temperate bacteriophages. As part of a program to characterize the genetic makeup of prophages associated with clinical strains and to assess the potential roles that they play in the biology and pathogenesis in their host, we performed comparative genomic analysis of 10 temperate pneumococcal phages. All of the genomes are organized into five major gene clusters: lysogeny, replication, packaging, morphogenesis, and lysis clusters. All of the phage particles observed showed a Siphoviridae morphology. The only genes that are well conserved in all the genomes studied are those involved in the integration and the lysis of the host in addition to two genes, of unknown function, within the replication module. We observed that a high percentage of the open reading frames contained no similarities to any sequences catalogued in public databases; however, genes that were homologous to known phage virulence genes, including the pblB gene of Streptococcus mitis and the vapE gene of Dichelobacter nodosus, were also identified. Interestingly, bioinformatic tools showed the presence of a toxin-antitoxin system in the phage phiSpn_6, and this represents the first time that an addition system in a pneumophage has been identified. Collectively, the temperate pneumophages contain a diverse set of genes with various levels of similarity among them. PMID:19502408

  13. Comparative Genomic Analysis of Ten Streptococcus pneumoniae Temperate Bacteriophages?

    Romero, Patricia; Croucher, Nicholas J.; Hiller, N. Luisa; Hu, Fen Z.; Ehrlich, Garth D.; Bentley, Stephen D.; Garca, Ernesto; Mitchell, Tim J.

    2009-01-01

    Streptococcus pneumoniae is an important human pathogen that often carries temperate bacteriophages. As part of a program to characterize the genetic makeup of prophages associated with clinical strains and to assess the potential roles that they play in the biology and pathogenesis in their host, we performed comparative genomic analysis of 10 temperate pneumococcal phages. All of the genomes are organized into five major gene clusters: lysogeny, replication, packaging, morphogenesis, and lysis clusters. All of the phage particles observed showed a Siphoviridae morphology. The only genes that are well conserved in all the genomes studied are those involved in the integration and the lysis of the host in addition to two genes, of unknown function, within the replication module. We observed that a high percentage of the open reading frames contained no similarities to any sequences catalogued in public databases; however, genes that were homologous to known phage virulence genes, including the pblB gene of Streptococcus mitis and the vapE gene of Dichelobacter nodosus, were also identified. Interestingly, bioinformatic tools showed the presence of a toxin-antitoxin system in the phage ?Spn_6, and this represents the first time that an addition system in a pneumophage has been identified. Collectively, the temperate pneumophages contain a diverse set of genes with various levels of similarity among them. PMID:19502408

  14. Carbon sequestration in managed temperate coniferous forests under climate change

    Dymond, C. C.; Beukema, S.; Nitschke, C. R.; Coates, K. D.; Scheller, R. M.

    2015-12-01

    Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management and climate change on the Copper-Pine creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the Net Sector Productivity, a carbon accounting metric that integrates above and below-ground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions and this indicates that both of these components need to be taken into account in when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator - Net Sector Productivity, promises to be useful in assessing management effectiveness and mitigation activities.

  15. Sliding mode controllers for a tempered glass furnace.

    Almutairi, Naif B; Zribi, Mohamed

    2016-01-01

    This paper investigates the design of two sliding mode controllers (SMCs) applied to a tempered glass furnace system. The main objective of the proposed controllers is to regulate the glass plate temperature, the upper-wall temperature and the lower-wall temperature in the furnace to a common desired temperature. The first controller is a conventional sliding mode controller. The key step in the design of this controller is the introduction of a nonlinear transformation that maps the dynamic model of the tempered glass furnace into the generalized controller canonical form; this step facilitates the design of the sliding mode controller. The second controller is based on a state-dependent coefficient (SDC) factorization of the tempered glass furnace dynamic model. Using an SDC factorization, a simplified sliding mode controller is designed. The simulation results indicate that the two proposed control schemes work very well. Moreover, the robustness of the control schemes to changes in the system׳s parameters as well as to disturbances is investigated. In addition, a comparison of the proposed control schemes with a fuzzy PID controller is performed; the results show that the proposed SDC-based sliding mode controller gave better results. PMID:26614678

  16. Comparative visual ecophysiology of mid-Atlantic temperate reef fishes

    Andrij Z. Horodysky

    2013-11-01

    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.

  17. Carbon sequestration in managed temperate coniferous forests under climate change

    Dymond, Caren C.; Beukema, Sarah; Nitschke, Craig R.; Coates, K. David; Scheller, Robert M.

    2016-03-01

    Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management, and climate change in the Copper-Pine Creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the net sector productivity, a carbon accounting metric that integrates aboveground and belowground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions, and this indicates that both of these components need to be taken into account when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator, net sector productivity, promises to be useful in assessing management effectiveness and mitigation activities.

  18. Black-tailed Godwits in West African winter staging areas : habitat use and hunting-related mortality

    Kleijn, D.; Kamp, J.; Monteiro, H.; Ndiaye, I.; Wymenga, E.; Zwarts, L.

    2010-01-01

    The persistence of the Dutch Black-tailed Godwit population depends largely on high adult survival. Adult survival may be influenced by hunting pressure and land use change in the wintering area, the West African coastal zone. Here we examine hunting pressure on and habitat use of Black-tailed Godwits in West African rice-growing areas. The Black-tailed Godwit is exposed to hunting throughout the core wintering area in West Africa but hunting related mortality does not seem to be the main dri...

  19. Winter refuge for Aedes aegypti and Ae. albopictus mosquitoes in Hanoi during Winter.

    Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru

    2014-01-01

    Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures concrete tanks and this preference increased in winter. Even in winter, the lowest water temperature found in concrete tanks was >14°C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994-97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indicate a concern about concrete tanks serving as foci for Ae. aegypti to expand their distribution in cooler regions. PMID:24752230

  20. The possibility of tribopair lifetime extending by welding of quenched and tempered stainless steel with quenched and tempered carbon steel

    V. Marušić

    2015-04-01

    Full Text Available In the conditions of tribocorrosion wear, extending of parts lifetime could be achieved by using stainless steel,which is hardened to sufficiently high hardness. In the tribosystem bolt/ bushing shell/link plate of the bucket elevator transporter conveyor machine, the previously quenched and tempered martensitic stainless steel for bolts is hardened at ≈47 HRC and welded with the quenched and tempered high yield carbon steel for bolts. Additional material, based on Cr-Ni-Mo (18/8/6 is used. The microstructure and hardness of welded samples are tested. On the tensile tester, resistance of the welded joint is tested with a simulated experiment. Dimensional control of worn tribosystem elements was performed after six months of service.

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

    IRWIN, J.J.

    1998-11-30

    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.

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

    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

  3. Winter Refuge for Aedes aegypti and Ae. albopictus Mosquitoes in Hanoi during Winter

    Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru

    2014-01-01

    Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures 14°C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994–97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indic...

  4. A climatology of planetary wave-driven mesospheric inversion layers in the extratropical winter

    France, J. A.; Harvey, V. L.; Randall, C. E.; Collins, R. L.; Smith, A. K.; Peck, E. D.; Fang, X.

    2015-01-01

    inversion layers (MILs) are a useful diagnostic to simultaneously investigate middle atmosphere radiation, chemistry, and dynamics in high-top general circulation models. Climatologies of long-lived extratropical winter MILs observed by the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) satellite instruments are compared to MILs in the Whole Atmosphere Community Climate Model (WACCM). In general, MIL location, amplitude, and thickness statistics in WACCM are in good agreement with the observations, though WACCM middle- and high-latitude winter MILs occur 30%-50% more often than in MLS and SABER. This work suggests that planetary wave-driven MILs may form as high as 90 km. In the winter, MILs display a wave-1 pattern in both hemispheres, forming most often over the region where the climatological winter stratospheric anticyclones occur. These MILs are driven by the decay of vertically propagating planetary waves in the mesospheric surf zone in both observations and in the model. At the base of polar inversions there is climatological local ascent and cooling situated atop the stratospheric anticyclones, which enhances the cold base of the MILs near 60 km and 120E longitude.

  5. Prediction of hardness in pieces of quenched and tempered steel

    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)

  6. Round herring (genus Etrumeus) contain distinct evolutionary lineages coincident with a biogeographic barrier along Australia’s southern temperate coastline

    DiBattista, Joseph

    2014-08-28

    Molecular genetic surveys of marine fishes have revealed that some widely distributed species are actually a composite of multiple evolutionary lineages. This is apparent in the round herrings (genus Etrumeus), wherein a globally distributed taxon (Etrumeus sadina Mitchill 1814) has proven to contain at least seven valid taxa, with more likely awaiting discovery. Here, we survey evolutionary lineages of the nominal E. sadina (formerly E. teres, a junior synonym) across the southern temperate zone of Australia, a marine region divided into three biogeographic provinces based primarily on the distribution of intertidal faunas. Results from morphological and mitochondrial DNA data reveal two evolutionary lineages corresponding to eastern and southwestern provinces (d = 0.007 for cytochrome c oxidase subunit I and d = 0.017 for cytochrome b), possibly initiated by the Bassian Isthmus between Australia and Tasmania during low sea-level stands. The Australian round herring is also genetically distinct from the nearest congeneric forms in the Indian and Pacific Oceans, with a corresponding modal difference in gill-raker counts in most cases. Based on these data, we resurrect the title Etrumeus jacksoniensis for the Australian round herring. While the Bassian Isthmus may have initiated the partition of evolutionary lineages within Australia, additional oceanographic and ecological factors must reinforce this separation in order to maintain diagnostic genetic differences along a continuous temperate coastline. © 2014 Springer-Verlag Berlin Heidelberg.

  7. Winter feeding strategies for suckler cows in cold climatic conditions

    Manninen, Merja

    2007-01-01

    In Finland, suckler cow production is carried out in circumstances characterized by a long winter period and a short grazing period. The traditional winter housing system for suckler cows has been insulated or uninsulated buildings, but there is a demand for developing less expensive housing systems. In addition, more information is needed on new winter feeding strategies, carried out in inexpensive winter facilities with conventional (hay, grass silage, straw) or alternative (treated straw, ...

  8. AGA predicts winter jump in residential gas price

    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%

  9. Sharp View of Gullies in Southern Winter

    2006-01-01

    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.

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

    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

  11. $\\mu$-tempered metadynamics: Artifact independent convergence times for wide hills

    Dickson, Bradley M

    2015-01-01

    Recent analysis of well-tempered metadynamics (WTmetaD) showed that it converges without mollification artifacts in the bias potential. Here we explore how metadynamics heals mollification artifacts, how healing impacts convergence time, and whether alternative temperings may be used to improve efficiency. We introduce "$\\mu$-tempered" metadynamics as a simple tempering scheme, inspired by a related mollified adaptive biasing potential (mABP), that results in artifact independent convergence of the free energy estimate. We use a toy model to examine the role of artifacts in WTmetaD and solvated alanine dipeptide to compare the well-tempered and $\\mu$-tempered frameworks demonstrating fast convergence for hill widths as large as $60^{\\circ}$ for $\\mu$TmetaD.

  12. μ-tempered metadynamics: Artifact independent convergence times for wide hills

    Dickson, Bradley M.

    2015-12-01

    Recent analysis of well-tempered metadynamics (WTmetaD) showed that it converges without mollification artifacts in the bias potential. Here, we explore how metadynamics heals mollification artifacts, how healing impacts convergence time, and whether alternative temperings may be used to improve efficiency. We introduce "μ-tempered" metadynamics as a simple tempering scheme, inspired by a related mollified adaptive biasing potential, that results in artifact independent convergence of the free energy estimate. We use a toy model to examine the role of artifacts in WTmetaD and solvated alanine dipeptide to compare the well-tempered and μ-tempered frameworks demonstrating fast convergence for hill widths as large as 60∘ for μTmetaD.

  13. The circadian basis of winter depression

    Lewy, Alfred J.; Lefler, Bryan J.; Emens, Jonathan S.; Bauer, Vance K.

    2006-01-01

    The following test of the circadian phase-shift hypothesis for patients with winter depression (seasonal affective disorder, or SAD) uses low-dose melatonin administration in the morning or afternoon/evening to induce phase delays or phase advances, respectively, without causing sleepiness. Correlations between depression ratings and circadian phase revealed a therapeutic window for optimal alignment of circadian rhythms that also appears to be useful for phase-typing SAD patients for the pur...

  14. Soil and radiocaesium contamination of winter fodders

    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

  15. Measuring Transpiration to Regulate Winter Irrigation Rates

    Samuelson, Lisa [Auburn University

    2006-11-08

    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.

  16. Effects of winter swimming on haematological parameters

    Lombardi, Giovanni; Ricci, Christian; Banfi, Giuseppe

    2011-01-01

    Introduction: Winter swimming represents an intensive short-term exposure to cold, and thus it is considered a strong physical stress. Cold-based treatments, i.e. immersions in cold water, are spreading in sport medicine for improving recovery following muscle traumas, although a universal acceptance of that method is not still achieved. Materials and methods: Fifteen healthy subjects (13 males and 2 females) were recruited among the participants to a 150 meters long swimming race in cold ...

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

    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

  18. Autumn and winter anomalies in ionospheric absorption as measured by riometers

    Ranta, H.

    1984-05-01

    Seasonal variations of ionospheric absorption were studied using riometer (A2) measurements over a wide latitude range. In agreement with the results of earlier studies of A1 radiowave absorption, equinoctial maxima of approximately equal amplitude are observed in the auroral zone and near the equator. However, at intermediate 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 anomaly in riometer absorption is observed at much higher geographic latitude in the Southern Hemisphere, but at comparable geomagnetic latitudes in both hemispheres. The winter anomaly was seen only in absorption values calculated at constant solar zenith angle.

  19. Autumn and Winter Anomalies in Ionospheric Absorption as Measured by Riometers

    Ranta, H.

    1984-01-01

    Seasonal variations of ionospheric absorption were studied using riometer (A2) measurements over a wide latitude range. In agreement with the results of earlier studies of A1 radiowave absorption, equinoctial maxima of approximately equal amplitude are observed in the auroral zone and near the equator. However, at intermediate 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 anomaly in riometer absorption is observed at much higher geographic latitude in the Southern Hemisphere, but at comparable geomagnetic latitudes in both hemispheres. The winter anomaly was seen only in absorption values calculated at constant solar zenith angle.

  20. Perennial Forage Kochia for Increased Production of Winter Grazed Pastures

    Grazing forage kochia (Kochia prostrata) during fall/winter has improved livestock health and reduced winter feeding costs. The objectives of this study were to compare forage production/quality and livestock performance of traditional winter pastures versus pastures with forage kochia. Two kochia...

  1. 76 FR 73503 - Amendment of Class E Airspace; Winters, TX

    2011-11-29

    ... controlled airspace at Winters Municipal Airport (76 FR 53354) Docket No. FAA-2011-0608. Interested parties.... Decommissioning of the Winters NDB and cancellation of the NDB approach at Winters Municipal Airport, as well as...'' under DOT Regulatory Policies and Procedures (44 FR 11034; February 26, 1979); and (3) does not...

  2. Dehydration in the Winter Arctic Tropopause Region

    Pfister, Leonhard; Jensen, Eric; Podolske, James; Selkirk, Henry; Anderson, Bruce; Avery, Melody; Diskin. Glenn

    2004-01-01

    Recent work has shown that limited amounts of tropospheric air can penetrate as much as 1 km into the middleworld stratosphere during the arctic winter. This, coupled with temperatures that are cold enough to produce saturation mixing ratios of less than 5 ppmv at the tropopause, results in stratospheric cloud formation and upper tropospheric dehydration. Even though these "cold outbreaks" occupy only a small portion of the area in the arctic (1-2%), their importance is magnified by an order of magnitude because of the air flow through them. This is reinforced by evidence of progressive drying through the winter measured during SOLVE-1. The significance of this process lies in its effect on the upper tropospheric water content of the middle and high latitude tropopause region, which plays an important role in regulating the earth's radiative balance. There appears to be significant year-to-year variability in the incidence of the cold outbreaks. This work has two parts. First, we describe case studies of dehydration taken from the SOLVE and SOLVE2 aircraft sampling missions during the Arctic winters of 2000 and 2003 respectively. Trajectory based microphysical modeling is employed to examine the sensitivity of the dehydration to microphysical parameters and the nature of sub-grid scale temperature fluctuations. We then examine the year-to-year variations in potential dehydration using a trajectory climatology.

  3. Reproductive performance of different breeds of broiler rabbits under sub-temperate climatic conditions

    D. Kumar

    2013-09-01

    Full Text Available This study was conducted to assess the effect of breed, season, age and weight of doe at mating on reproductive performance of 4 broiler rabbit breeds, Grey Giant, White Giant, Soviet Chinchilla, and New Zealand White, reared under standard management practices in sub-temperate climatic conditions of India. They were first mated at 6 to 7 mo of age, whereupon an extensive breeding system (re-mating after weaning was followed. Weaning was done 42 d after kindling. The data from the records on reproduction consisting of 503 matings and 377 kindlings were analysed. The parameters considered were fertility rate, litter size at birth (LSB, litter weight at birth (LWB, litter size at weaning (LSW, litter weight at weaning (LWW, doe weight at mating (DWM, gestation length and sex ratio. Among 4 breeds, the LSB, LWB and LSW were higher in Grey Giant followed by White Giant, Soviet Chinchilla and New Zealand White. The LSB and LSW in Grey Giant breed differed significantly (P<0.05 from Soviet Chinchilla and New Zealand White. Season had significant (P<0.05 effect on LSW with higher values during spring (5.680.24, followed by summer (5.290.30, winter (5.130.25 and autumn (4.170.49. The body weight of doe at service significantly influenced fertility. The fertility increased as body weight increased. The age of the doe at mating had a significant effect on LSW, with higher values for does more than 2 yr and less than 1 yr old compared to 1- to 2-yr old does. The parity did not affect any of the parameters studied. It is concluded that the factors studied affect the reproductive performance of rabbit does. Grey Giant breed showed the highest litter size at birth and weaning, and the highest litter size and weight at weaning was in spring.

  4. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse).

    Erguler, Kamil; Smith-Unna, Stephanie E; Waldock, Joanna; Proestos, Yiannis; Christophides, George K; Lelieveld, Jos; Parham, Paul E

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  5. Large-Scale Modelling of the Environmentally-Driven Population Dynamics of Temperate Aedes albopictus (Skuse)

    Erguler, Kamil; Smith-Unna, Stephanie E.; Waldock, Joanna; Proestos, Yiannis; Christophides, George K.; Lelieveld, Jos; Parham, Paul E.

    2016-01-01

    The Asian tiger mosquito, Aedes albopictus, is a highly invasive vector species. It is a proven vector of dengue and chikungunya viruses, with the potential to host a further 24 arboviruses. It has recently expanded its geographical range, threatening many countries in the Middle East, Mediterranean, Europe and North America. Here, we investigate the theoretical limitations of its range expansion by developing an environmentally-driven mathematical model of its population dynamics. We focus on the temperate strain of Ae. albopictus and compile a comprehensive literature-based database of physiological parameters. As a novel approach, we link its population dynamics to globally-available environmental datasets by performing inference on all parameters. We adopt a Bayesian approach using experimental data as prior knowledge and the surveillance dataset of Emilia-Romagna, Italy, as evidence. The model accounts for temperature, precipitation, human population density and photoperiod as the main environmental drivers, and, in addition, incorporates the mechanism of diapause and a simple breeding site model. The model demonstrates high predictive skill over the reference region and beyond, confirming most of the current reports of vector presence in Europe. One of the main hypotheses derived from the model is the survival of Ae. albopictus populations through harsh winter conditions. The model, constrained by the environmental datasets, requires that either diapausing eggs or adult vectors have increased cold resistance. The model also suggests that temperature and photoperiod control diapause initiation and termination differentially. We demonstrate that it is possible to account for unobserved properties and constraints, such as differences between laboratory and field conditions, to derive reliable inferences on the environmental dependence of Ae. albopictus populations. PMID:26871447

  6. Marine Biodiversity in Temperate Western Australia: Multi-Taxon Surveys of Minden and Roe Reefs

    Zoe Richards; Lisa Kirkendale; Glenn Moore; Andrew Hosie; John Huisman; Monika Bryce; Loisette Marsh; Clay Bryce; Ana Hara; Nerida Wilson; Susan Morrison; Oliver Gomez; Jenelle Ritchie; Corey Whisson; Mark Allen

    2016-01-01

    A growing body of evidence indicates that temperate marine ecosystems are being tropicalised due to the poleward extension of tropical species. Such climate mediated changes in species distribution patterns have the potential to profoundly alter temperate communities, as this advance can serve to push temperate taxa, many of which are southern Australian endemics, southward. These changes can lead to cascading effects for the biodiversity and function of coastal ecosystems, including contract...

  7. The influence of kinetics of phase transformations during tempering on high-speed steels mechanical properties

    Bała, P.; PACYNA J.

    2010-01-01

    Purpose: The main purpose of the presented paper was the determination of the influence of the phase transformation kinetics, at tempering, on the properties of high-speed steels. In order to achieve this aim investigations of the influence of continuous heating and isothermal tempering from the as-quenched state on the investigated steels hardness were performed. The advancement degree change obtained by changing the heating rate and by pre-tempering was applied in strength properties studie...

  8. The kinetics of phase transformations during the tempering of HS6-5-2 steel

    Krawczyk, J.; PACYNA J.; Bała, P.

    2009-01-01

    Purpose: This work contains a detailed description of the kinetics of phase transformations during tempering of hardened HS6-5-2 high-speed steel. Moreover, the microstructure development in tested samples, reflecting the extend of the phase transformations during tempering, was discussed too.Design/methodology/approach: CHT diagram, illustrating the kinetics of phase transformations during continuous heating (tempering) from as-quenched state of investigated steel, was ...

  9. Replica-Exchange Simulated Tempering Method for Simulations of Frustrated Systems

    A.Mitsutake; OKAMOTO, Y.

    2000-01-01

    We propose a new method for the determination of the weight factor for the simulated tempering method. In this method a short replica-exchange simulation is performed and the simulated tempering weight factor is obtained by the multiple-histogram reweighting techniques. The new algorithm is particularly useful for studying frustrated systems with rough energy landscape where the determination of the simulated tempering weight factor by the usual iterative process becomes very difficult. The e...

  10. Spring molybdenum enrichment in scallop shells: a potential tracer of diatom productivity in temperate coastal environments (Brittany, NW France)

    Barats, A.; Amouroux, D.; Pécheyran, C.; Chauvaud, L.; Thébault, J.; Donard, O. F. X.

    2010-01-01

    Skeletal molybdenum/calcium ([Mo]/[Ca])shell ratios were examined in shells of the Great Scallop Pecten maximus collected in temperate coastal environments of Western Europe (42 to 49° N). These ratios were determined by quantitative LA-ICP-MS analyses of daily striae taken every third day (i.e. a temporal resolution of 3 days) in 36 flat valves (2-years old; 3 shells/year). Variations of ([Mo]/[Ca])shell ratios were significant and reproducible for scallops from the same population, from different years (1998-2004) and temperate coastal locations (NW France). The [Mo]/[Ca])shell ratios exhibit typical profiles characterized by a background content, below the detection limit for this method (Brest (France) was investigated in particular because of its long term observations on scallop communities, environmental variables, and high resolution analyses of dissolved Mo in bottom seawater in 2000. In 2000, dissolved Mo exhibited a significant increase in concentration just preceding the maximum ([Mo]/[Ca])shell ratio. Both the intense monitoring survey in 2000 and over the 7-year period indicates that the ([Mo]/[Ca])shell maximum is directly influenced by spring changes of environmental conditions at the sediment water interface (SWI), occurring subsequent to the intense and periodic spring bloom. Spring maxima of ([Mo]/[Ca])shell ratios are closely correlated to the extent of silicic acid and nitrate depletion in seawater between winter and late spring (r2=0.878 and 0.780, pBrest. The Mo inputs in bottom waters and subsequent shell enrichment are thus suggested to be directly or indirectly influenced by such biogenic material input at the SWI. The [Mo]/[Ca])shell records thus reveal unexpected biogeochemical cycles of Mo influenced by coastal spring productivity, faithfully recorded in scallop shells.

  11. Deformation, fracture, and mechanical properties of low-temperature-tempered martensite in SAE 43xx steels

    Saeglitz, M. [Deutsche Bahn AG, Brandenburg-Kirchmoeser (Germany); Krauss, G. [Colorado School of Mines, Golden, CO (United States). Dept. of Metallurgical and Materials Engineering

    1997-02-01

    Uniaxial tensile tests were performed on 4330, 4340, and 4350 steels in the as-quenched (AQ) condition and after quenching and tempering at 150 C, 175 C, and 200 C for times of 10 minutes, 1 hour, and 10 hours, respectively. Strength parameters decreased and ductility parameters increased continuously with increasing tempering. Mechanical properties are presented as a function of tempering conditions and steel carbon content, and hardness and ultimate strength changes are given as a function of Hollomon-Jaffe tempering parameters. All tempered specimens, except for some lightly tempered 4350 specimens, deformed plastically through necking instability and failed by ductile fracture. The stresses required for the ductile fracture, estimated from an analysis of the interfacial stresses at particles in the neck at fracture, showed no systematic variation with carbon content of tempering conditions despite significant variations in deformation and strain hardening. The AQ specimens of the 4340 and 4350 steels, and some of the lightly tempered 4350 steels, failed by brittle mechanisms. The deformation and fracture of the low-temperature-tempered 43xx steels are discussed in terms of the changes in fine structure, namely, the formation of transition carbides and a rearranged dislocation substructure that evolve from an AQ martensitic substructure consisting of dislocations with and without carbon atom segregation.

  12. Effect of tempering temperature on the microstructure and mechanical properties in mooring chain steel

    The tensile behavior of a mooring chain steel was investigated after tempering at 560 °C, 600 °C, 640 °C temperatures. With increasing tempering temperature, the steel displayed not only a decrease in strength, but also a slight increase in strain-hardening ability between the proof and ultimate stress. In the meantime, an upper yield point appeared at 640 °C tempered samples. The susceptibility to hydrogen-induced embrittlement reduced on the same precharging hydrogen condition as tempering temperature elevated. These changes of tensile behavior were elucidated from their microstructure variation observed by transmission electron microscopy (TEM) and electron back-scattered diffraction (EBSD)

  13. Bionomics of temperate and tropical Culicoides midges: knowledge gaps and consequences for transmission of Culicoides-borne viruses.

    Purse, B V; Carpenter, S; Venter, G J; Bellis, G; Mullens, B A

    2015-01-01

    Culicoides midges are abundant hematophagous flies that vector arboviruses of veterinary and medical importance. Dramatic changes in the epidemiology of Culicoides-borne arboviruses have occurred since 1998, including the emergence of exotic viruses in northern temperate regions, increases in global disease incidence, and enhanced virus diversity in tropical zones. Drivers may include changes in climate, land use, trade, and animal husbandry. New Culicoides species and new wild reservoir hosts have been implicated in transmission, highlighting the dynamic nature of pathogen-vector-host interactions. Focusing on potential vector species worldwide and key elements of vectorial capacity, we review the sensitivity of Culicoides life cycles to abiotic and biotic factors. We consider implications for designing control measures and understanding impacts of environmental change in different ecological contexts. Critical geographical, biological, and taxonomic knowledge gaps are prioritized. Recent developments in genomics and mathematical modeling may enhance ecological understanding of these complex arbovirus systems. PMID:25386725

  14. Altitudinal variation in soil organic carbon stock in coniferous subtropical and broadleaf temperate forests in Garhwal Himalaya

    Kumar Munesh

    2009-08-01

    Full Text Available Abstract Background The Himalayan zones, with dense forest vegetation, cover a fifth part of India and store a third part of the country reserves of soil organic carbon (SOC. However, the details of altitudinal distribution of these carbon stocks, which are vulnerable to forest management and climate change impacts, are not well known. Results This article reports the results of measuring the stocks of SOC along altitudinal gradients. The study was carried out in the coniferous subtropical and broadleaf temperate forests of Garhwal Himalaya. The stocks of SOC were found to be decreasing with altitude: from 185.6 to 160.8 t C ha-1 and from 141.6 to 124.8 t C ha-1 in temperature (Quercus leucotrichophora and subtropical (Pinus roxburghii forests, respectively. Conclusion The results of this study lead to conclusion that the ability of soil to stabilize soil organic matter depends negatively on altitude and call for comprehensive theoretical explanation

  15. Influence of austenitizing temperature on the fracture toughness of Ni-Cr-Mo steel weld zone

    Effect of heat-treatment condition on the fracture behavior at the flash buttweld zone of rolled Ni-Cr-Mo steel has been studied. Specimens were austenized at 870-1200 deg C, and then tempered at 200-650 deg C. Experimental observation (specially at low tempering temperature around 250 deg C) fits the following relation between plain strain fracture toughness, K1c, and the grain size of austenite, D, K1c=a+bD1/2 where a and b are constants. The measured a and b are 6.9 and 15.1, respectively, for the base metal, and 30 and 15.6 respectively, for the weld zone, when K1c and D are given by units of MPa m1/2 and ?m, respectively. (Author)

  16. Emergent Toxins in North Atlantic Temperate Waters: A Challenge for Monitoring Programs and Legislation

    Marisa Silva

    2015-03-01

    Full Text Available Harmful Algal Blooms (HAB are complex to manage due to their intermittent nature and their severe impact on the economy and human health. The conditions which promote HAB have not yet been fully explained, though climate change and anthropogenic intervention are pointed as significant factors. The rise of water temperature, the opening of new sea canals and the introduction of ship ballast waters all contribute to the dispersion and establishment of toxin-producing invasive species that promote the settling of emergent toxins in the food-chain. Tetrodotoxin, ciguatoxin, palytoxin and cyclic imines are commonly reported in warm waters but have also caused poisoning incidents in temperate zones. There is evidence that monitoring for these toxins exclusively in bivalves is simplistic and underestimates the risk to public health, since new vectors have been reported for these toxins and as well for regulated toxins such as PSTs and DSTs. In order to avoid public health impacts, there is a need for adequate monitoring programs, a need for establishing appropriate legislation, and a need for optimizing effective methods of analysis. In this review, we will compile evidence concerning emergent marine toxins and provide data that may indicate the need to restructure the current monitoring programs of HAB.

  17. Near-neutral carbon dioxide balance at a seminatural, temperate bog ecosystem

    Hurkuck, Miriam; Brümmer, Christian; Kutsch, Werner L.

    2016-02-01

    The majority of peatlands in the temperate zone is subjected to drainage and agricultural land use and have been found to be anthropogenic emission hot spots for greenhouse gases. At the same time, many peatlands receive increased atmospheric nitrogen (N) deposition by intensive agricultural practices. Here we provide eddy covariance measurements determining net ecosystem carbon dioxide (CO2) exchange at a protected but moderately drained ombrotrophic bog in Northwestern Germany over three consecutive years. The region is dominated by intensive agricultural land use with total (wet and dry) atmospheric N deposition being about 25 kg N ha-1 yr-1. The investigated peat bog was a small net CO2 sink during all three years ranging from -9 to -73 g C m-2 yr-1. We found temperature- and light-dependent ecosystem respiration (Reco) and gross primary production, respectively, but only weak correlations to water table depths despite large interannual and seasonal variability. Significant short-term effects of atmospheric N deposition on CO2 flux components could not be observed, as the primary controlling factors for N deposition and C sequestration, i.e., fertilization of adjacent fields as well as temperature and light availability, respectively, exceeded potential interactions between the two.

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

    Watanabe Tsutomu

    2007-05-01

    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.

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

    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)

  20. Pure stands of temperate forest tree species modify soil respiration and N turnover

    Brggemann, N.; Rosenkranz, P.; Papen, H.; Pilegaard, K.; Butterbach-Bahl, K.

    2005-04-01

    The effects of five different tree species common in the temperate zone, i.e. beech (Fagus sylvatica L.), pedunculate oak (Quercus robur L.), Norway spruce (Picea abies [L.] Karst), Japanese larch (Larix leptolepis [Sichold and Zucc.] Gordon) and mountain pine (Pinus mugo Turra), on soil respiration, gross N mineralization and gross nitrification rates were investigated. Soils were sampled in spring and summer 2002 at a forest trial in Western Jutland, Denmark, where pure stands of the five tree species of the same age were growing on the same soil. Soil respiration, gross rates of N mineralization and nitrification were significantly higher in the organic layers than in the Ah horizons for all tree species and both sampling dates. In summer (July), the highest rates of soil respiration, gross N mineralization and gross nitrification were found in the organic layer under spruce, followed by beech > larch > oak > pine. In spring (April), these rates were also higher under spruce compared to the other tree species, but were significantly lower than in summer. For the Ah horizons no clear seasonal trend was observed for any of the processes examined. A linear relationship between soil respiration and gross N mineralization (r2=0.77), gross N mineralization and gross nitrification rates (r2=0.72), and between soil respiration and gross nitrification (r2=0.81) was found. The results obtained underline the importance of considering the effect of forest type on soil C and N transformations.

  1. Holocene precipitation in the coastal temperate rainforest complex of southern British Columbia, Canada

    Brown, K. J.; Fitton, R. J.; Schoups, G.; Allen, G. B.; Wahl, K. A.; Hebda, R. J.

    2006-11-01

    Pollen data from 69 surface samples from Vancouver Island, Canada, were used to develop a ratio index of precipitation, Douglas fir-western hemlock index (DWHI). DWHI ratios were combined with interpolated estimates of mean annual precipitation to develop pollen-based precipitation transfer functions. The optimal regression model, with a predictive range of 960-2600 mm, was applied to 10 Holocene lake sediment records distributed across a ˜150 km long coastal-inland precipitation gradient. Predicted precipitation was spatially modelled in a geographic information system to examine the spatio-temporal history of precipitation from this representative portion of the coastal temperate rainforest (CTR) complex of western North America. The reconstructions show widespread early Holocene dry conditions coupled with a steep east-west precipitation gradient. Thereafter, the modern precipitation gradient established 7000 years ago, illustrating that the CTR complex has experienced marked short-distance east-west changes in precipitation in the past. Changes in the abundance of arboreal and non-arboreal vegetation, as well as fire disturbance, are often concomitant with changes in Holocene precipitation. Given the precipitation and vegetation history of the region, conservation initiatives should focus on the moist outer coastal zone since it appears to have the greatest amount of resilience to perturbations in precipitation, whereas monitoring programs for signs of climate change should be initiated in central and eastern areas as they appear sensitive to changes in the moisture regime.

  2. Holocene Precipitation in the Coastal Temperate Rainforest Complex of Western North America

    Brown, K. J.; Fitton, R. J.; Schoups, G.; Allen, G. B.; Wahl, K. A.; Hebda, R. J.

    2006-12-01

    Pollen data from 69 surface samples from Vancouver Island, Canada, were used to develop a ratio index of precipitation, DWHI (Douglas fir-western hemlock index). DWHI ratios were combined with interpolated estimates of mean annual precipitation to develop pollen-based precipitation transfer functions. The optimal regression model, with a predictive range of 960-2600 mm, was applied to 10 Holocene lake sediment records distributed across a ~150 km long coastal-inland precipitation gradient. Predicted precipitation was spatially modelled in a geographic information system to examine the spatio-temporal history of precipitation from this representative portion of the coastal temperate rainforest (CTR) complex of western North America. The reconstructions show widespread early Holocene dry conditions coupled with a steep east-west precipitation gradient. Thereafter, the modern precipitation gradient established 7000 years ago, illustrating that the CTR complex has experienced marked short-distance east-west changes in precipitation in the past. Changes in the abundance of arboreal and non-arboreal vegetation, as well as fire disturbance, are often concomitant with changes in Holocene precipitation. Given the precipitation and vegetation history of the region, conservation initiatives should focus on the moist outer coastal zone since it appears to have the greatest amount of resilience to perturbations in precipitation, whereas monitoring programs for signs of climate change should be initiated in central areas as they appear sensitive to changes in the moisture regime.

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

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

    2007-01-01

    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.

  4. Determining efficient temperature sets for the simulated tempering method

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

    2014-07-01

    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.

  5. Carbon sequestration in managed temperate coniferous forests under climate change

    C. C. Dymond

    2015-12-01

    Full Text Available Management of temperate forests has the potential to increase carbon sinks and mitigate climate change. However, those opportunities may be confounded by negative climate change impacts. We therefore need a better understanding of climate change alterations to temperate forest carbon dynamics before developing mitigation strategies. The purpose of this project was to investigate the interactions of species composition, fire, management and climate change on the Copper–Pine creek valley, a temperate coniferous forest with a wide range of growing conditions. To do so, we used the LANDIS-II modelling framework including the new Forest Carbon Succession extension to simulate forest ecosystems under four different productivity scenarios, with and without climate change effects, until 2050. Significantly, the new extension allowed us to calculate the Net Sector Productivity, a carbon accounting metric that integrates above and below-ground carbon dynamics, disturbances, and the eventual fate of forest products. The model output was validated against literature values. The results implied that the species optimum growing conditions relative to current and future conditions strongly influenced future carbon dynamics. Warmer growing conditions led to increased carbon sinks and storage in the colder and wetter ecoregions but not necessarily in the others. Climate change impacts varied among species and site conditions and this indicates that both of these components need to be taken into account in when considering climate change mitigation activities and adaptive management. The introduction of a new carbon indicator – Net Sector Productivity, promises to be useful in assessing management effectiveness and mitigation activities.

  6. Increased Carbon Sink in Temperate and Boreal Forests

    Liski, J.; Korotkov, A.V.; Prins, C.F.L.; Karjalainen, T. (Tommi); Victor, D.G.; P. E. Kauppi

    2003-01-01

    An intense search is under way to identify the ??missing sink?? in the world carbon budget of perhaps 2 Pg year??1 (petagrams, or billion tonnes) of carbon, but its location and mechanism have proved elusive. Here we use a new forest inventory data set to estimate the carbon sink and the carbon pool of woody biomass in 55 countries that account for nearly all temperate or boreal forests and approximately half the world??s total forest area. In each country there was a net accu...

  7. Resolutions of tempered representations of reductive p-adic groups

    Opdam, Eric; Solleveld, Maarten

    2013-01-01

    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-Tit...

  8. The Research and Application of Webpage Temper-proofing System

    Wang Yongquan

    2012-06-01

    Full Text Available With the sharp increase of hacking attacks over the last couple of years, web application security has become a key concern. The attack to websites, especially the explosion of webpage interpolating incidents has becomeone of the most serious problems of it. In this paper, the system adopts Web server core embedded technology to imbed tamper detection module and application protection module into the Web server, define correspondingstrategies for temper-proofing, and realize the real-time monitoring and protection of web pages and the dynamic content in databases.

  9. Tempered fractional Feynman-Kac equation: Theory and examples

    Wu, Xiaochao; Deng, Weihua; Barkai, Eli

    2016-03-01

    Functionals of Brownian and non-Brownian motions have diverse applications and attracted a lot of interest among scientists. This paper focuses on deriving the forward and backward fractional Feynman-Kac equations describing the distribution of the functionals of the space and time-tempered anomalous diffusion, belonging to the continuous time random walk class. Several examples of the functionals are explicitly treated, including the occupation time in half-space, the first passage time, the maximal displacement, the fluctuations of the occupation fraction, and the fluctuations of the time-averaged position.

  10. The Fracture Process of Tempered Soda-Lime-Silica Glass

    Nielsen, Jens Henrik; Olesen, John Forbes; Stang, Henrik

    2009-01-01

    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 “Whirl...

  11. Transport in the spatially tempered, fractional Fokker–Planck equation

    A study of truncated Lévy flights in super-diffusive transport in the presence of an external potential is presented. The study is based on the spatially tempered, fractional Fokker–Planck (TFFP) equation in which the fractional diffusion operator is replaced by a tempered fractional diffusion (TFD) operator. We focus on harmonic (quadratic) potentials and periodic potentials with broken spatial symmetry. The main objective is to study the dependence of the steady-state probability density function (PDF), and the current (in the case of periodic potentials) on the level of tempering, λ, and on the order of the fractional derivative in space, α. An expansion of the TFD operator for large λ is presented, and the corresponding equation for the coarse grained PDF is obtained. The steady-state PDF solution of the TFFP equation for a harmonic potential is computed numerically. In the limit λ → ∞, the PDF approaches the expected Boltzmann distribution. However, nontrivial departures from this distribution are observed for finite (λ > 0) truncations, and α ≠ 2. In the study of periodic potentials, we use two complementary numerical methods: a finite-difference scheme based on the Grunwald–Letnikov discretization of the truncated fractional derivatives and a Fourier-based spectral method. In the limit λ → ∞, the PDFs converges to the Boltzmann distribution and the current vanishes. However, for α ≠ 2, the PDF deviates from the Boltzmann distribution and a finite non-equilibrium ratchet current appears for any λ > 0. The current is observed to converge exponentially in time to the steady-state value. The steady-state current exhibits algebraical decay with λ, as J ∼ λ−ζ, for α ⩾ 1.75. However, for α ⩽ 1.5, the steady-state current decays exponentially with λ, as J ∼ e−ξλ. In the presence of an asymmetry in the TFD operator, the tempering can lead to a current reversal. A detailed numerical study is presented on the dependence of the current on λ and the physical parameters of the system. (paper)

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

    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)

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

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

    1989-03-01

    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.

  14. Home advantage in the Winter Olympics (1908-1998).

    Balmer, N J; Nevill, A M; Williams, A M

    2001-02-01

    We obtained indices of home advantage, based on the medals won by competing nations, for each event held at the Winter Olympics from 1908 to 1998. These indices were designed to assess home advantage while controlling for nation strength, changes in the number of medals on offer and the performance of 'non-hosting' nations. Some evidence of home advantage was found in figure skating, freestyle skiing, ski jumping, alpine skiing and short track speed skating. In contrast, little or no home advantage was observed in ice hockey, Nordic combined, Nordic skiing, bobsled, luge, biathlon or speed skating. When all events were combined, a significant home advantage was observed (P = 0.029), although no significant differences in the extent of home advantage were found between events (P > 0.05). When events were grouped according to whether they were subjectively assessed by judges, significantly greater home advantage was observed in the subjectively assessed events (P = 0.037). This was a reflection of better home performances, suggesting that judges were scoring home competitors disproportionately higher than away competitors. Familiarity with local conditions was shown to have some effect, particularly in alpine skiing, although the bobsled and luge showed little or no advantage over other events. Regression analysis showed that the number of time zones and direction of travel produced no discernible trends or differences in performance. PMID:11217011

  15. Adaptation of barley to mild winters: A role for PPDH2

    Casao M Cristina

    2011-11-01

    Full Text Available Abstract Background Understanding the adaptation of cereals to environmental conditions is one of the key areas in which plant science can contribute to tackling challenges presented by climate change. Temperature and day length are the main environmental regulators of flowering and drivers of adaptation in temperate cereals. The major genes that control flowering time in barley in response to environmental cues are VRNH1, VRNH2, VRNH3, PPDH1, and PPDH2 (candidate gene HvFT3. These genes from the vernalization and photoperiod pathways show complex interactions to promote flowering that are still not understood fully. In particular, PPDH2 function is assumed to be limited to the ability of a short photoperiod to promote flowering. Evidence from the fields of biodiversity, ecogeography, agronomy, and molecular genetics was combined to obtain a more complete overview of the potential role of PPDH2 in environmental adaptation in barley. Results The dominant PPDH2 allele is represented widely in spring barley cultivars but is found only occasionally in modern winter cultivars that have strong vernalization requirements. However, old landraces from the Iberian Peninsula, which also have a vernalization requirement, possess this allele at a much higher frequency than modern winter barley cultivars. Under field conditions in which the vernalization requirement of winter cultivars is not satisfied, the dominant PPDH2 allele promotes flowering, even under increasing photoperiods above 12 h. This hypothesis was supported by expression analysis of vernalization-responsive genotypes. When the dominant allele of PPDH2 was expressed, this was associated with enhanced levels of VRNH1 and VRNH3 expression. Expression of these two genes is needed for the induction of flowering. Therefore, both in the field and under controlled conditions, PPDH2 has an effect of promotion of flowering. Conclusions The dominant, ancestral, allele of PPDH2 is prevalent in southern European barley germplasm. The presence of the dominant allele is associated with early expression of VRNH1 and early flowering. We propose that PPDH2 promotes flowering of winter cultivars under all non-inductive conditions, i.e. under short days or long days in plants that have not satisfied their vernalization requirement. This mechanism is indicated to be a component of an adaptation syndrome of barley to Mediterranean conditions.

  16. Body Condition in the Eurasian Woodcock Wintering in the West of France: Practical Study for Wildlife Management during Cold Spells

    Robin, J-P.

    2005-06-01

    Full Text Available The Eurasian woodcock (Scolopax rusticola is one of the most widespread species of the Scolopax genus in temperate regions. However, population levels can be greatly affected by harsh cold spells that led woodcocks to starve by exhaustion of their body fuels. To better understand the vulnerability of woodcocks to such climatic conditions it is of a major importance to determine the amount of their body reserves (both lipids and proteins throughout the wintering season. This was performed on 55 individuals collected by hunters in the western part of France during two consecutive winters under mild weather conditions. Body reserves, that can be mobilised, were determined as the difference between the total amount of lipids and proteins minus the values obtained on starved individuals found dead during previous cold spells. Overall, body reserves did not significantly change over both winters (p > 0.40, the maximal mean value (1539 ± 117 kJ being however reached in January. Storing body fuels would not adversely affect wing and power loading, suggesting that the amount of body reserves would agree with the "starvation-predation trade-off". If woodcocks sit through a cold spell, their mean survival time (or fasting endurance would be 6.5 ± 0.5 days; 25 to 40% of the birds would have a life expectancy of 7-9 days, and about 8 to17% less than 5 days. On the contrary, if woodcocks immediately leave their wintering quarter, they would be able to perform a trip of 740 ± 50 km, 20 to 40% of the woodcocks being able to fly over 750 km. Body mass explains only 47 to 57% of the fasting endurance and flight autonomy variations, and therefore we recommend a further carcass analysis to accurately estimate body condition. These results underscore the suitability of determining the state of body reserves for practical cases of population management and hunting policy during cold spells.

  17. Standardized precipitation index zones for Mexico

    Giddings, L.; Soto, M. [Instituto de Ecologia, A.C., Xalapa, Veracruz (Mexico); Rutherford, B.M.; Maarouf, A. [Faculty of Environmental Studies, York University, Toronto, Ontario (Canada)

    2005-01-01

    Precipitation zone systems exists for Mexico 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 nino. 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 zones 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. [Spanish] Existen varios sistemas de zonificacion de Mexico basados en la estacionalidad, cantidad de precipitacion, climas y divisiones geograficas, pero ninguno es conveniente para el estudio de la relacion de la precipitacion con fenomenos tales como El Nino. En este trabajo se presenta un conjunto de siete zonas empiricas exclusivamente mexicanas y seis compartidas, derivadas de tres series de imagenes de SPI (Indice Estandarizado de la Precipitacion), desde 1940 a 1989: una serie de 582 imagenes mensuales (SPI-12), una series de 50 imagenes (SPI-6) de meses de invierno (noviembre a abril), y otra de 50 imagenes (SPI-6) de meses de verano (mayo a octubre). Al examinar imagenes de componentes principales y de clasificaciones no supervisadas, se descubrio que las tres series tenian una zonificacion similar. Un conjunto de campos de entrenamiento fue utilizado para clasificar las tres series. Despues de doce tanteos las zonas resultantes, presentadas aqui, fueron casi identicas para las tres series, con variaciones principalmente alrededor de los bordes. Un conjunto de zonas sencillas definidas por pocos vertices puede ser usado para operaciones practicas. En general, las zonas son homogeneas, 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 climaticas. Se mencionan posibles aplicaciones.

  18. Genetic and Morphological Diversity of Temperate and Tropical Isolates of Phytophthora capsici.

    Bowers, J H; Martin, F N; Tooley, P W; Luz, E D M N

    2007-04-01

    ABSTRACT Phytophthora capsici is a diverse species causing disease on a broad range of both temperate and tropical plants. In this study, we used cultural characteristics, amplified fragment length polymorphism (AFLP), and DNA sequence analyses of the ribosomal internal transcribed spacer (ITS) region and mitochondrial cytochrome oxidase II (cox II) genes to characterize temperate and tropical isolates from a wide range of host species. All but one temperate isolate grew at 35 degrees C, while all tropical isolates did not. All but two tropical isolates formed chlamydospores, while temperate isolates did not. There was strong bootstrap support for separation of temperate and tropical isolates using AFLP analysis; however, the temperate isolates appeared as a subgroup within the observed variation of the tropical isolates. The majority of temperate isolates clustered within a single clade with low variation regardless of host or geographical origin, while the tropical isolates were more variable and grouped into three distinct clades. Two clades of tropical isolates grouped together and were affiliated closely with the temperate isolates, while the third tropical clade was more distantly related. Phylogenetic analysis of the ITS regions resulted in similar groupings and variation within and between the temperate and tropical isolates as with the AFLP results. Sequence divergence among isolates and clades was low, with more variation within the tropical isolates than within the temperate isolates. Analysis of other species revealed shorter branch lengths separating temperate and tropical isolates than were observed in comparisons among other phylogenetically closely related species in the genus. Analysis of cox II sequence data was less clear. Although the temperate and tropical isolates grouped together apart from other species, there was no bootstrap support for separating these isolates. Restriction fragment length polymorphism (RFLP) analysis of the ITS regions separated the temperate and tropical isolates, as in the AFLP and ITS phylogenetic analyses. However, RFLP analysis of the cox I and II gene cluster did not distinguish between temperate and tropical isolates. The differences in grouping of isolates in these two RFLP studies should be helpful in identifying isolate subgroups. Our data do not fully clarify whether or not temperate and tropical isolates should be separated into different species. The available worldwide data are incomplete and the full range of variation in the species is not yet known. We suggest refraining from using the epithet P. tropicalis until more data are available. PMID:18943290

  19. Mutations of winter wheat induced by radionuclide contamination resulted from Chernobyl catastrophe

    It is shown that a high level of radionuclide contamination has been retained until 1992 in the zone of Chernobyl catastrophe (village Chistogalovka and the town of Pripyat).This causes the increase of the frequency of chromosome aberrations and visible mutations within the winter wheat (2.49 to 6.39 times) and (2.6 to 13.0 times), correspondingly. Chromosome aberrations and visible mutations which effect qualitative and quantitative characteristics, revealed over a long period of time, indicate that the retaining level of radionuclide contamination continues to be an efficient mutagen factor of the environment

  20. Winter Refuge for Aedes aegypti and Ae. albopictus Mosquitoes in Hanoi during Winter

    Tsunoda, Takashi; Cuong, Tran Chi; Dong, Tran Duc; Yen, Nguyen Thi; Le, Nguyen Hoang; Phong, Tran Vu; Minakawa, Noboru

    2014-01-01

    Dengue occurs throughout the year in Hanoi, Vietnam, despite winter low temperatures 14°C, exceeding the developmental zero point of Ae. aegypti. Although jars, drums and concrete tanks were the dominant containers previously (1994–97) in Hanoi, currently the percentage of residences with concrete tanks was still high while jars and drums were quite low. Our study showed that concrete tanks with broken lids allowing mosquitoes access were important winter refuge for Ae. aegypti. We also indicate a concern about concrete tanks serving as foci for Ae. aegypti to expand their distribution in cooler regions. PMID:24752230

  1. Nuclear weapons free zone

    An idea on creation of nuclear weapon free zones was arisen with purpose for prevention of a new nuclear countries creation. To 2001 there are 4 Regional Agreements on creation of nuclear weapon free zones. Some uninhabited areas of the world also were declared as nuclear weapon free zones (Arctic Zone, Antarctica, the Sun and Moon surfaces and the seabed. The Chapter VII of Non-proliferation Treaty confirms the right of a countries for creation of nuclear weapon free zones on their perspective territories. In the paper is pointed out that measures on creation of regional nuclear free zones further to regional and global peace and security. Nuclear weapon free zones have been became a part of the non-proliferation regime

  2. Mitochondrial ageing of a polar and a temperate mud clam.

    Philipp, Eva; Pörtner, Hans-Otto; Abele, Doris

    2005-05-01

    We investigated mitochondrial ageing in a temperate (Mya arenaria) and an Antarctic (Laternula elliptica) mud clam, with similar lifestyle (benthic filter feeders) but different maximum life spans (MLSP), 13 and 36 years, respectively. The short-lived temperate M. arenaria showed a more pronounced decrease in mitochondrial function (respiration, respiratory control ratio, proton leak, membrane potential) with age than the long-lived Antarctic L. elliptica. H2O2 generation rates at habitat temperature were far higher in the short-lived M. arenaria compared to L. elliptica. Reactive oxygen species (ROS) production as proportion of the mitochondrial oxygen consumption rate (%H2O2/O2) increased significantly with age in M. arenaria, whereas in L. elliptica the proportion remained unchanged. Lower rates of mitochondrial H2O2 generation were presumably due to mild uncoupling as L. elliptica mitochondria showed higher proton leak compared to M. arenaria mitochondria. The results are discussed in to the light of the "Free Radical-Rate of Living theory", (Pearl, R., 1928. The Rate of Living. Alfred Knopf, New York; Harman, D., 1956. Aging: a theory based on free radical and radiation biology. J. Gerontol. 11, 298-300) and the "Uncoupling to Survive" hypothesis (Brand, M.D., 2000. Uncoupling to survive? The role of mitochondrial inefficiency in ageing. Exp. Gerontol. 35, 811-820). PMID:15811430

  3. Beneficial Effects of Temperate Forage Legumes that Contain Condensed Tannins

    Jennifer W. MacAdam

    2015-07-01

    Full Text Available The two temperate forage legumes containing condensed tannins (CT that promote ruminant production are birdsfoot trefoil (Lotus corniculatus L.; BFT and sainfoin (Onobrychis viciifolia Scop.; SF. Both are well-adapted to the cool-temperate climate and alkaline soils of the Mountain West USA. Condensed tannins comprise a diverse family of bioactive chemicals with multiple beneficial functions for ruminants, including suppression of internal parasites and enteric methane. Birdsfoot trefoil contains 10 to 40 g·CT·kg−1 dry matter (DM, while SF contains 30 to 80 g·CT·kg−1 DM. Our studies have focused on these two plant species and have demonstrated consistently elevated rates of gain for beef calves grazing both BFT and SF. Novel results from our BFT research include carcass dressing percentages and consumer sensory evaluations equivalent to feedlot-finished steers and significantly greater than grass-finished steers, but with omega-3 fatty acid concentrations equal to grass-finished beef. We have further demonstrated that ruminants fed BFT or SF will consume more endophyte-infected tall fescue (Schedonorus arundinaceus (Schreb. Dumort. forage or seed than ruminants fed a non-CT forage legume. There is great potential value for sustainable livestock production in the use of highly digestible, nitrogen-fixing legumes containing tannins demonstrated to improve ruminant productivity.

  4. Photoautotrophic microorganisms as a carbon source for temperate soil invertebrates.

    Schmidt, Olaf; Dyckmans, Jens; Schrader, Stefan

    2016-01-01

    We tested experimentally if photoautotrophic microorganisms are a carbon source for invertebrates in temperate soils. We exposed forest or arable soils to a (13)CO2-enriched atmosphere and quantified (13)C assimilation by three common animal groups: earthworms (Oligochaeta), springtails (Hexapoda) and slugs (Gastropoda). Endogeic earthworms (Allolobophora chlorotica) and hemiedaphic springtails (Ceratophysella denticulata) were highly (13)C enriched when incubated under light, deriving up to 3.0 and 17.0%, respectively, of their body carbon from the microbial source in 7 days. Earthworms assimilated more (13)C in undisturbed soil than when the microbial material was mixed into the soil, presumably reflecting selective surface grazing. By contrast, neither adult nor newly hatched terrestrial slugs (Deroceras reticulatum) grazed on algal mats. Non-photosynthetic (13)CO2 fixation in the dark was negligible. We conclude from these preliminary laboratory experiments that, in addition to litter and root-derived carbon from vascular plants, photoautotrophic soil surface microorganisms (cyanobacteria, algae) may be an ecologically important carbon input route for temperate soil animals that are traditionally assigned to the decomposer channel in soil food web models and carbon cycling studies. PMID:26740559

  5. Nitrous oxide emission reduction in temperate biochar-amended soils

    R. Felber

    2012-01-01

    Full Text Available 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 incubation experiment two different temperate agricultural soils were amended with green waste and coffee grounds biochar. N2O and CO2 emissions were measured at the beginning and end of a three month incubation. The experiments were conducted under three different conditions (no additional nutrients, glucose addition, and nitrate and glucose addition representing different field conditions. We found mean N2O emission reductions of 60 % compared to soils without addition of biochar. The reduction depended on biochar type and soil type as well as on the age of the samples. CO2 emissions were slightly reduced, too. NO3 but not NH4+ concentrations were significantly reduced shortly after biochar incorporation. Despite the highly significant suppression of N2O emissions biochar effects should not be transferred one-to-one to field conditions but need to be tested accordingly.

  6. Recruitment facilitation can drive alternative states on temperate reefs.

    Baskett, Marissa L; Salomon, Anne K

    2010-06-01

    How the combination of positive and negative species interactions acts to drive community dynamics is a fundamental question in ecology. Here we explore one aspect of this question by expanding the theory of predator-mediated coexistence to include the potential role of facilitation between the predator and inferior competitor. To motivate and illustrate our simple model, we focus on sea-urchin-algae interactions in temperate rocky reef systems and incorporate recruitment facilitation, a common characteristic of marine systems. Specifically, the model represents sea urchin grazing on macroalgae, macroalgal competition with crustose coralline algae (CCA), and facilitation of sea urchin recruitment to CCA. These interactions generate alternative stable states, one dominated by macroalgae and the other by urchins, which do not occur when recruitment facilitation of urchins to CCA is ignored. Therefore, recruitment facilitation provides a possible mechanism for alternative kelp forest and urchin barren states in temperate marine systems, where storm events or harvesting of urchins or their predators can drive switches between states that are difficult to reverse. In systems with such dynamics, spatial management such as no-take marine reserves may play a crucial role in protecting community structure by increasing the resilience to shifts between states. PMID:20583717

  7. Prediction of quenched and tempered steel and cast steel properties

    B. Smoljan

    2011-12-01

    Full Text Available Purpose: The influence of processing parameters, such as pouring temperature and cooling rate during the casting, as well as application of hot working and pre-heat treatment, on strength and toughness of quenched and tempered steel was investigated.Design/methodology/approach: Strength and toughness were presented by yield strength and Charpy-V notch toughness, respectively. Experimental procedure of material properties optimization was done using the 25-2 factor experiment.Findings: It was found out that yield strength is insensitive on differences between applied manufacturing processes, but by application of hot working and with appropriate pouring temperature the Charpy-V notch toughness is increased. Also, Charpy-V notch toughness is increased by interactive effect of the appropriate cooling rate during the casting and application of hot working.Research limitations/implications: The research was focused mainly on Charpy-V notch toughness of carbon and low alloyed heat treatable steels.Practical implications: The established algorithms can be used for prediction of tensile strength, yield strength and Charpy-V notch toughness in heat treating practice.Originality/value: Original relation for prediction of quenched and tempered steel and cast steel Charpy-V notch toughness are developed.

  8. Comparison Between Atmospheric Turbidity Coefficients of Desert and Temperate Climates

    Hamdy K. Elminir

    2001-01-01

    Full Text Available Knowledge of the solar radiation available on the earth’s surface is essential for the development of solar energy devices and for estimating of their performance efficiencies. For this purpose it is helpful to study the attenuation of direct normal irradiance by the atmosphere, in terms of fundamental quantities, including optical thickness, relative optical air mass, water vapor content, and aerosol amount. In the present article, we will not deal with cloudy atmospheres because of their great variability in space and time, but will focus our attention on atmospheres characterized by the complete absence of condensed water. The objectives of this article are to report data on aerosol optical depth and atmospheric turbidity coefficients for a desert climate, and to compare them with those of a temperate climate. Aerosol optical depth, the Linke turbidity factor, TL, and ngström turbidity coefficients, _, 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 ngström 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.

  9. Climate change impacts: winter tourism adapatation strategies

    Prudent, P.; Boudires, V.; Marcelpoil, E.

    2008-01-01

    Snow cover plays an important role for the mountain environment, representing a living area for some species, a huge water storage function, etc. While in the past it was seen as an obstacle in the European Alps because farmers could not work their fields or the passes were more difficult to cross, in the 20th century it became an important source of wealth and was even nicknamed white gold. Indeed, snow represents the primary resource for winter tourism in the French Alps. / Ce bulletin s...

  10. Carbon dioxide partial pressure and 13C content of north temperate and boreal lakes at spring ice melt

    Striegl, R.G.; Kortelainen, P.; Chanton, J.P.; Wickland, K.P.; Bugna, G.C.; Rantakari, M.

    2001-01-01

    Carbon dioxide (CO2) accumulates under lake ice in winter and degasses to the atmosphere after ice melt. This large springtime CO2 pulse is not typically considered in surface-atmosphere flux estimates, because most field studies have not sampled through ice during late winter. Measured CO2 partial pressure (pCO2) of lake surface water ranged from 8.6 to 4,290 Pa (85-4,230 ??atm) in 234 north temperate and boreal lakes prior to ice melt during 1998 and 1999. Only four lakes had surface pCO2 less than or equal to atmospheric pCO2, whereas 75% had pCO2 >5 times atmospheric. The ??13CDIC (DIC = ??CO2) of 142 of the lakes ranged from -26.28??? to +0.95.???. Lakes with the greatest pCO2 also had the lightest ??13CDIC, which indicates respiration as their primary CO2 source. Finnish lakes that received large amounts of dissolved organic carbon from surrounding peatlands had the greatest pCO2. Lakes set in noncarbonate till and bedrock in Minnesota and Wisconsin had the smallest pCO2 and the heaviest ??13CDIC, which indicates atmospheric and/or mineral sources of C for those lakes. Potential emissions for the period after ice melt were 2.36 ?? 1.44 mol CO2 m-2 for lakes with average pCO2 values and were as large as 13.7 ?? 8.4 mol CO2 m-2 for lakes with high pCO2 values.

  11. An Inventory of Terrestrial Mammals at National Parks in the Northeast Temperate Network and Sagamore Hill National Historic Site

    Gilbert, A.T.; O'Connell, A.F., Jr.; Annand, E.M.; Talancy, N.W.; Sauer, J.R.; Nichols, J.D.

    2008-01-01

    An inventory of mammals was conducted during 2004 at nine national park sites in the Northeast Temperate Network (NETN): Acadia National Park (NP), Marsh-Billings-Rockefeller National Historical Park (NHP), Minute Man NHP, Morristown NHP, Roosevelt-Vanderbilt National Historic Site (NHS), Saint-Gaudens NHS, Saugus Iron Works NHS, Saratoga NHP, and Weir Farm NHS. Sagamore Hill NHS, part of the Northeast Coastal and Barrier Network (NCBN), was also surveyed. Each park except Acadia NP was sampled twice, once in the winter/spring and again in the summer/fall. During the winter/spring visit, indirect measure (IM) sampling arrays were employed at 2 to 16 stations and included sampling by remote cameras, cubby boxes (covered trackplates), and hair traps. IM stations were established and re-used during the summer/fall sampling period. Trapping was conducted at 2 to 12 stations at all parks except Acadia NP during the summer/fall period and consisted of arrays of small-mammal traps, squirrel-sized live traps, and some fox-sized live traps. We used estimation-based procedures and probabilistic sampling techniques to design this inventory. A total of 38 species was detected by IM sampling, trapping, and field observations. Species diversity (number of species) varied among parks, ranging from 8 to 24, with Minute Man NHP having the most species detected. Raccoon (Procyon lotor), Virginia Opossum (Didelphis virginiana), Fisher (Martes pennanti), and Domestic Cat (Felis silvestris) were the most common medium-sized mammals detected in this study and White-footed Mouse (Peromyscus leucopus), Northern Short-tailed Shrew (Blarina brevicauda), Deer Mouse (P. maniculatus), and Meadow Vole (Microtus pennsylvanicus) the most common small mammals detected. All species detected are considered fairly common throughout their range including the Fisher, which has been reintroduced in several New England states. We did not detect any state or federal endangered or threatened species.

  12. 40 CFR 426.60 - Applicability; description of the automotive glass tempering subcategory.

    2010-07-01

    ... automotive glass tempering subcategory. 426.60 Section 426.60 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GLASS MANUFACTURING POINT SOURCE CATEGORY Automotive Glass Tempering Subcategory § 426.60 Applicability; description of the automotive glass...

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

    Fu Hanguang

    2012-08-01

    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.

  14. Influence of heating rate on sorbitic transformation temperature of tempering C45 steel

    A. Kulawik

    2011-04-01

    Full Text Available In this paper the analysis of speed heating influence on sorbitic transormation temperature of tempering C45 steel is presented. On thebasis of dilatometric research, functions associating heating time with initial and final temperature of sorbitic transformation have beendetermined as well as the size structural (γ and thermal (α expansion coefficients of quenching and tempering structures have beenestimated.

  15. Parallel Tempering in Lattice QCD with O(a)-Improved Wilson Fermions

    Joo, Balint; Irving, Alan C.; Sexton, James C.; Pendleton, Brian; Pickles, Stephen M.; Sroczynski, Zbigniew; collaboration, UKQCD

    1998-01-01

    We present details of our investigation of the Parallel Tempering algorithm. We consider the application of action matching technology to the selection of parameters. We then present a simple model of the autocorrelations for a particular parallel tempered system. Finally we present numerical results from applying the algorithm to lattice QCD with O(a)-improved dynamical fermions with twin ensemble systems

  16. Influence of heating rate on sorbitic transformation temperature of tempering C45 steel

    A. Kulawik; Winczek, J.

    2011-01-01

    In this paper the analysis of speed heating influence on sorbitic transormation temperature of tempering C45 steel is presented. On thebasis of dilatometric research, functions associating heating time with initial and final temperature of sorbitic transformation have beendetermined as well as the size structural (γ) and thermal (α) expansion coefficients of quenching and tempering structures have beenestimated.

  17. Features of Stressed State and Properties of Glass Tempered by Contact Method

    Zheplynskyy, Taras; Serkiz, Oksana

    2013-01-01

    The main advantages of the new energy-saving method of glass tempering are described. It was found that the thickness of the strengthened layer and the ratio of tensile to compressive stresses is greater than in a traditional method. The influence of tempering on the value of microhardness and contact angle of glass surface was investigated.

  18. The case for water activity as a specification for wheat tempering and flour production

    Moisture plays an important role in processing wheat grain into flour, from proper grain tempering to the stability of the flour. Moisture properties of dry grain, tempered grain, and finished flour are currently tracked using moisture content. However, stability factors such as microbial growth and...

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

    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.

  20. Use of the integration elements encoded by the temperate lactococcal bacteriophage TP901-1

    Brøndsted, Lone; Hammer, Karin

    1999-01-01

    P region seem to be necessary for site-specific integration of the temperate bacteriophage TP901-1. By use of the integrative elements (attP and orf1) expressed by the temperate lactococcal bacteriophage TP901-1, a system for obtaining stable chromosomal single-copy transcriptional fusions in L. lactis was...