WorldWideScience

Sample records for winter chill models

  1. A global analysis of the comparability of winter chill models for fruit and nut trees.

    Science.gov (United States)

    Luedeling, Eike; Brown, Patrick H

    2011-05-01

    Many fruit and nut trees must fulfill a chilling requirement to break their winter dormancy and resume normal growth in spring. Several models exist for quantifying winter chill, and growers and researchers often tacitly assume that the choice of model is not important and estimates of species chilling requirements are valid across growing regions. To test this assumption, Safe Winter Chill (the amount of winter chill that is exceeded in 90% of years) was calculated for 5,078 weather stations around the world, using the Dynamic Model [in Chill Portions (CP)], the Chilling Hours (CH) Model and the Utah Model [Utah Chill Units (UCU)]. Distributions of the ratios between different winter chill metrics were mapped on a global scale. These ratios should be constant if the models were strictly proportional. Ratios between winter chill metrics varied substantially, with the CH/CP ratio ranging between 0 and 34, the UCU/CP ratio between -155 and +20 and the UCU/CH ratio between -10 and +5. The models are thus not proportional, and chilling requirements determined in a given location may not be valid elsewhere. The Utah Model produced negative winter chill totals in many Subtropical regions, where it does not seem to be useful. Mean annual temperature and daily temperature range influenced all winter chill ratios, but explained only between 12 and 27% of the variation. Data on chilling requirements should always be amended with information on the location and experimental conditions of the study in which they were determined, ideally including site-specific conversion factors between winter chill models. This would greatly facilitate the transfer of such information across growing regions, and help prepare growers for the impact of climate change.

  2. Climate change affects winter chill for temperate fruit and nut trees.

    Science.gov (United States)

    Luedeling, Eike; Girvetz, Evan H; Semenov, Mikhail A; Brown, Patrick H

    2011-01-01

    Temperate fruit and nut trees require adequate winter chill to produce economically viable yields. Global warming has the potential to reduce available winter chill and greatly impact crop yields. We estimated winter chill for two past (1975 and 2000) and 18 future scenarios (mid and end 21st century; 3 Global Climate Models [GCMs]; 3 greenhouse gas emissions [GHG] scenarios). For 4,293 weather stations around the world and GCM projections, Safe Winter Chill (SWC), the amount of winter chill that is exceeded in 90% of all years, was estimated for all scenarios using the "Dynamic Model" and interpolated globally. We found that SWC ranged between 0 and about 170 Chill Portions (CP) for all climate scenarios, but that the global distribution varied across scenarios. Warm regions are likely to experience severe reductions in available winter chill, potentially threatening production there. In contrast, SWC in most temperate growing regions is likely to remain relatively unchanged, and cold regions may even see an increase in SWC. Climate change impacts on SWC differed quantitatively among GCMs and GHG scenarios, with the highest GHG leading to losses up to 40 CP in warm regions, compared to 20 CP for the lowest GHG. The extent of projected changes in winter chill in many major growing regions of fruits and nuts indicates that growers of these commodities will likely experience problems in the future. Mitigation of climate change through reductions in greenhouse gas emissions can help reduce the impacts, however, adaption to changes will have to occur. To better prepare for likely impacts of climate change, efforts should be undertaken to breed tree cultivars for lower chilling requirements, to develop tools to cope with insufficient winter chill, and to better understand the temperature responses of tree crops.

  3. Overhead irrigation increased winter chilling and floral bud ...

    African Journals Online (AJOL)

    Eucalyptus nitens requires a sufficiently cold winter to produce flower buds. In areas in South Africa where E. nitens commercial plantations as well as breeding and production seed orchards are located, winter chilling is often insufficient for floral bud initiation. Hence, under such conditions, E. nitens floral bud and seed ...

  4. Climatic changes lead to declining winter chill for fruit and nut trees in California during 1950-2099.

    Science.gov (United States)

    Luedeling, Eike; Zhang, Minghua; Girvetz, Evan H

    2009-07-16

    Winter chill is one of the defining characteristics of a location's suitability for the production of many tree crops. We mapped and investigated observed historic and projected future changes in winter chill in California, quantified with two different chilling models (Chilling Hours, Dynamic Model). Based on hourly and daily temperature records, winter chill was modeled for two past temperature scenarios (1950 and 2000), and 18 future scenarios (average conditions during 2041-2060 and 2080-2099 under each of the B1, A1B and A2 IPCC greenhouse gas emissions scenarios, for the CSIRO-MK3, HadCM3 and MIROC climate models). For each scenario, 100 replications of the yearly temperature record were produced, using a stochastic weather generator. We then introduced and mapped a novel climatic statistic, "safe winter chill", the 10% quantile of the resulting chilling distributions. This metric can be interpreted as the amount of chilling that growers can safely expect under each scenario. Winter chill declined substantially for all emissions scenarios, with the area of safe winter chill for many tree species or cultivars decreasing 50-75% by mid-21st century, and 90-100% by late century. Both chilling models consistently projected climatic conditions by the middle to end of the 21st century that will no longer support some of the main tree crops currently grown in California, with the Chilling Hours Model projecting greater changes than the Dynamic Model. The tree crop industry in California will likely need to develop agricultural adaptation measures (e.g. low-chill varieties and dormancy-breaking chemicals) to cope with these projected changes. For some crops, production might no longer be possible.

  5. Running Club Warm Up Staves Off Winter's Chill

    CERN Multimedia

    2001-01-01

    Not deterred by winter's chill, over 900 runners met at the CERN Prévesin site for Escalade training. Think the sudden cold snap is a reason to stay indoors? Think again! The CERN running club has just recently had the honour of holding the November 11th Escalade training session, and with over 900 runners present at the Prévessin site it was clear that the chilly temperatures were no barrier whatsoever. The story behind Escalade training starts back in 1977 when a group of running enthusiasts from the Stade Genève club decided to organize a running race in the Old Town in conjunction with the Escalade festivities. They were told that no normal people would think of organizing a running race in the month of December, but fortunately they ignored the advice! From the initial 50 or so runners, these Escalade races have grown into an institution and now attract upwards of 15,000 people of all ages from 5 to over 80 each year. And with over 30% of each year's runners participat...

  6. Winter chilling speeds spring development of temperate butterflies.

    Science.gov (United States)

    Stålhandske, Sandra; Gotthard, Karl; Leimar, Olof

    2017-07-01

    Understanding and predicting phenology has become more important with ongoing climate change and has brought about great research efforts in the recent decades. The majority of studies examining spring phenology of insects have focussed on the effects of spring temperatures alone. Here we use citizen-collected observation data to show that winter cold duration, in addition to spring temperature, can affect the spring emergence of butterflies. Using spatial mixed models, we disentangle the effects of climate variables and reveal impacts of both spring and winter conditions for five butterfly species that overwinter as pupae across the UK, with data from 1976 to 2013 and one butterfly species in Sweden, with data from 2001 to 2013. Warmer springs lead to earlier emergence in all species and milder winters lead to statistically significant delays in three of the five investigated species. We also find that the delaying effect of winter warmth has become more pronounced in the last decade, during which time winter durations have become shorter. For one of the studied species, Anthocharis cardamines (orange tip butterfly), we also make use of parameters determined from previous experiments on pupal development to model the spring phenology. Using daily temperatures in the UK and Sweden, we show that recent variation in spring temperature corresponds to 10-15 day changes in emergence time over UK and Sweden, whereas variation in winter duration corresponds to 20 days variation in the south of the UK versus only 3 days in the south of Sweden. In summary, we show that short winters delay phenology. The effect is most prominent in areas with particularly mild winters, emphasising the importance of winter for the response of ectothermic animals to climate change. With climate change, these effects may become even stronger and apply also at higher latitudes. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  7. Deteriorating Inventory Model for Chilled Food

    OpenAIRE

    Yang, Ming-Feng; Tseng, Wei-Chung

    2015-01-01

    With many aspects that affect inventory policy, product perishability is a critical aspect of inventory policy. Most goods will deteriorate during storage and their original value will decline or be lost. Therefore, deterioration should be taken into account in inventory practice. Chilled food products are very common consumer goods that are, in fact, perishable. If the chilled food quality declines over time customers are less likely to buy it. The value the chilled food retains is, however,...

  8. Does the recent warming hiatus exist over northern Asia for winter wind chill temperature?

    Science.gov (United States)

    Ma, Ying

    2017-04-01

    Wind chill temperature (WCT) describes the joint effect of wind velocity and air temperature on exposed body skin and could support policy makers in designing plans to reduce the risks of notably cold and windy weather. This study examined winter WCT over northern Asia during 1973-2013 by analyzing in situ station data. The winter WCT warming rate over the Tibetan Plateau slowed during 1999-2013 (-0.04 °C/decade) compared with that during 1973-1998 (0.67 °C/decade). The winter WCT warming hiatus has also been observed in the remainder of Northern Asia with trends of 1.11 °C/decade during 1973-1998 but -1.02 °C/decade during 1999-2013, except for the Far East of Russia (FE), where the winter WCT has continued to heat up during both the earlier period of 1973-1998 (0.54 °C/decade) and the recent period of 1999-2013 (0.75 °C/decade). The results indicate that the influence of temperature on winter WCT is greater than that of wind speed over northern Asia. Atmospheric circulation changes associated with air temperature and wind speed were analyzed to identify the causes for the warming hiatus of winter WCT over northern Asia. The distributions of sea level pressure and 500 hPa height anomalies during 1999-2013 transported cold air from the high latitudes to middle latitudes, resulting in low air temperature over Northern Asia except for the Far East of Russia. Over the Tibetan Plateau, the increase in wind speed offset the increase in air temperature during 1999-2013. For the Far East, the southerly wind from the Western Pacific drove the temperature up during the 1999-2013 period via warm advection.

  9. Decision-relevant evaluation of climate models: A case study of chill hours in California

    Science.gov (United States)

    Jagannathan, K. A.; Jones, A. D.; Kerr, A. C.

    2017-12-01

    The past decade has seen a proliferation of different climate datasets with over 60 climate models currently in use. Comparative evaluation and validation of models can assist practitioners chose the most appropriate models for adaptation planning. However, such assessments are usually conducted for `climate metrics' such as seasonal temperature, while sectoral decisions are often based on `decision-relevant outcome metrics' such as growing degree days or chill hours. Since climate models predict different metrics with varying skill, the goal of this research is to conduct a bottom-up evaluation of model skill for `outcome-based' metrics. Using chill hours (number of hours in winter months where temperature is lesser than 45 deg F) in Fresno, CA as a case, we assess how well different GCMs predict the historical mean and slope of chill hours, and whether and to what extent projections differ based on model selection. We then compare our results with other climate-based evaluations of the region, to identify similarities and differences. For the model skill evaluation, historically observed chill hours were compared with simulations from 27 GCMs (and multiple ensembles). Model skill scores were generated based on a statistical hypothesis test of the comparative assessment. Future projections from RCP 8.5 runs were evaluated, and a simple bias correction was also conducted. Our analysis indicates that model skill in predicting chill hour slope is dependent on its skill in predicting mean chill hours, which results from the non-linear nature of the chill metric. However, there was no clear relationship between the models that performed well for the chill hour metric and those that performed well in other temperature-based evaluations (such winter minimum temperature or diurnal temperature range). Further, contrary to conclusions from other studies, we also found that the multi-model mean or large ensemble mean results may not always be most appropriate for this

  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..

    Directory of Open Access Journals (Sweden)

    Gulshan Kumar

    Full Text Available 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

  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.).

    Science.gov (United States)

    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

  12. The responses of antioxidant system in bitter melon, sponge gourd, and winter squash under flooding and chilling stresses

    Science.gov (United States)

    Do, Tuong Ha; Nguyen, Hoang Chinh; Lin, Kuan-Hung

    2018-04-01

    The objective of this paper was to review the responses of antioxidant system and physiological parameters of bitter melon (BM), sponge gourd (SG), and winter squash (WS) under waterlogged and low temperature conditions. The BM and SG plants were subjected to 0-72 h flooding treatments, and BM and WS plants were exposed to chilling at 12/7 °C (day/night) for 0-72 h. Different genotypes responded differently to environmental stress according to their various antioxidant system and physiological parameters. Increased ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities provided SG and WS plants with increased waterlogging and chilling stress tolerance, respectively, compared to BM plants. The APX gene from SG and the SOD gene from WS were then cloned, and the regulation of APX and SOD gene expressions under flooding and chilling stress, respectively, were also measured. Increased expression of APX and SOD genes was accompanied by the increased activity of the enzyme involved in detoxifying reactive oxygen species (ROS) in response to those stresses. Both APX and SOD activities can be used for selecting BM lines with the best tolerances to water logging and chilling stresses.

  13. Effect of winter-chilling treatment on flower bud induction in young pomelo trees

    International Nuclear Information System (INIS)

    Nakajima, Y.; Susanto, S.; Hasegawa, K.

    1992-01-01

    Two-year-old potted 'Tosa Buntan' pomelo (Citrus grandis (L.) Osbeck) trees on trifoliate orange (Poncirus trifoliata Raf.) rootstock grown in a plastic house were used in this study. The temperature of the plastic house was maintained at a maximum of 20°C during the day and 10°C minimum at night from November 1990 to mid-February 1991. On December 1990, a set of potted trees was transferred to each growth chamber which was kept at day/night temperature of 15°/5°C and 10°/10°C. A subgroup of these trees was exposed to these condition for 15, 30, 45, 60, and 75 days and then transferred to another growth chamber maintained at 30°/25°C (day/night). On 1 December 1990, 15 January, and 15 February 1991, a set of potted trees was transferred directly without chilling from the plastic house to the 30°/25°C growth chamber. No trees sprouted during the low temperature treatments. New buds sprouted early and more buds sprouted during subsequent exposure to 30°/25°C treatment as the low temperature was prolonged. The number of new shoots for 75-day exposure was greater at 15°/5°C than it was at 10°/10°C regimen and those kept in the plastic house. The number of inflorescences, flower buds, and flowers increased for the 60-day and over exposures, but very few flowers developed after a 15- or 30-day exposure. The numbers of flower buds and flowers per node were 2.27 and 2.05, respectively, for a 75-day exposure under the 15°/5°C regimen, whereas they were 0.81 and 0.76, respectively, in the 10°/10°C regimen. Sugar and carbohydrate contents in leaves increased while the N content decreased under prolonged low temperature treatments. (author)

  14. Effect of winter-chilling treatment on flower bud induction in young pomelo trees

    Energy Technology Data Exchange (ETDEWEB)

    Nakajima, Y. [Kochi Univ., Nankoku (Japan); Susanto, S.; Hasegawa, K.

    1992-09-15

    Two-year-old potted 'Tosa Buntan' pomelo (Citrus grandis (L.) Osbeck) trees on trifoliate orange (Poncirus trifoliata Raf.) rootstock grown in a plastic house were used in this study. The temperature of the plastic house was maintained at a maximum of 20°C during the day and 10°C minimum at night from November 1990 to mid-February 1991. On December 1990, a set of potted trees was transferred to each growth chamber which was kept at day/night temperature of 15°/5°C and 10°/10°C. A subgroup of these trees was exposed to these condition for 15, 30, 45, 60, and 75 days and then transferred to another growth chamber maintained at 30°/25°C (day/night). On 1 December 1990, 15 January, and 15 February 1991, a set of potted trees was transferred directly without chilling from the plastic house to the 30°/25°C growth chamber. No trees sprouted during the low temperature treatments. New buds sprouted early and more buds sprouted during subsequent exposure to 30°/25°C treatment as the low temperature was prolonged. The number of new shoots for 75-day exposure was greater at 15°/5°C than it was at 10°/10°C regimen and those kept in the plastic house. The number of inflorescences, flower buds, and flowers increased for the 60-day and over exposures, but very few flowers developed after a 15- or 30-day exposure. The numbers of flower buds and flowers per node were 2.27 and 2.05, respectively, for a 75-day exposure under the 15°/5°C regimen, whereas they were 0.81 and 0.76, respectively, in the 10°/10°C regimen. Sugar and carbohydrate contents in leaves increased while the N content decreased under prolonged low temperature treatments. (author)

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  17. Nut crop yield records show that budbreak-based chilling requirements may not reflect yield decline chill thresholds

    Science.gov (United States)

    Pope, Katherine S.; Dose, Volker; Da Silva, David; Brown, Patrick H.; DeJong, Theodore M.

    2015-06-01

    Warming winters due to climate change may critically affect temperate tree species. Insufficiently cold winters are thought to result in fewer viable flower buds and the subsequent development of fewer fruits or nuts, decreasing the yield of an orchard or fecundity of a species. The best existing approximation for a threshold of sufficient cold accumulation, the "chilling requirement" of a species or variety, has been quantified by manipulating or modeling the conditions that result in dormant bud breaking. However, the physiological processes that affect budbreak are not the same as those that determine yield. This study sought to test whether budbreak-based chilling thresholds can reasonably approximate the thresholds that affect yield, particularly regarding the potential impacts of climate change on temperate tree crop yields. County-wide yield records for almond ( Prunus dulcis), pistachio ( Pistacia vera), and walnut ( Juglans regia) in the Central Valley of California were compared with 50 years of weather records. Bayesian nonparametric function estimation was used to model yield potentials at varying amounts of chill accumulation. In almonds, average yields occurred when chill accumulation was close to the budbreak-based chilling requirement. However, in the other two crops, pistachios and walnuts, the best previous estimate of the budbreak-based chilling requirements was 19-32 % higher than the chilling accumulations associated with average or above average yields. This research indicates that physiological processes beyond requirements for budbreak should be considered when estimating chill accumulation thresholds of yield decline and potential impacts of climate change.

  18. Tradeoffs between chilling and forcing in satisfying dormancy requirements for Pacific Northwest tree species.

    Science.gov (United States)

    Harrington, Constance A; Gould, Peter J

    2015-01-01

    Many temperate and boreal tree species have a chilling requirement, that is, they need to experience cold temperatures during fall and winter to burst bud normally in the spring. Results from trials with 11 Pacific Northwest tree species are consistent with the concept that plants can accumulate both chilling and forcing units simultaneously during the dormant season and they exhibit a tradeoff between amount of forcing and chilling. That is, the parallel model of chilling and forcing was effective in predicting budburst and well chilled plants require less forcing for bud burst than plants which have received less chilling. Genotypes differed in the shape of the possibility line which describes the quantitative tradeoff between chilling and forcing units. Plants which have an obligate chilling requirement (Douglas-fir, western hemlock, western larch, pines, and true firs) and received no or very low levels of chilling did not burst bud normally even with long photoperiods. Pacific madrone and western redcedar benefited from chilling in terms of requiring less forcing to promote bud burst but many plants burst bud normally without chilling. Equations predicting budburst were developed for each species in our trials for a portion of western North America under current climatic conditions and for 2080. Mean winter temperature was predicted to increase 3.2-5.5°C and this change resulted in earlier predicted budburst for Douglas-fir throughout much of our study area (up to 74 days earlier) but later budburst in some southern portions of its current range (up to 48 days later) as insufficient chilling is predicted to occur. Other species all had earlier predicted dates of budburst by 2080 than currently. Recent warming trends have resulted in earlier budburst for some woody plant species; however, the substantial winter warming predicted by some climate models will reduce future chilling in some locations such that budburst will not consistently occur earlier.

  19. Application of modelling techniques in the food industry: determination of shelf-life for chilled foods

    NARCIS (Netherlands)

    Membré, J.M.; Johnston, M.D.; Bassett, J.; Naaktgeboren, G.; Blackburn, W.; Gorris, L.G.M.

    2005-01-01

    Microbiological modelling techniques (predictive microbiology, the Bayesian Markov Chain Monte Carlo method and a probability risk assessment approach) were combined to assess the shelf-life of an in-pack heat-treated, low-acid sauce intended to be marketed under chilled conditions. From a safety

  20. Risk management model of winter navigation operations

    International Nuclear Information System (INIS)

    Valdez Banda, Osiris A.; Goerlandt, Floris; Kuzmin, Vladimir; Kujala, Pentti; Montewka, Jakub

    2016-01-01

    The wintertime maritime traffic operations in the Gulf of Finland are managed through the Finnish–Swedish Winter Navigation System. This establishes the requirements and limitations for the vessels navigating when ice covers this area. During winter navigation in the Gulf of Finland, the largest risk stems from accidental ship collisions which may also trigger oil spills. In this article, a model for managing the risk of winter navigation operations is presented. The model analyses the probability of oil spills derived from collisions involving oil tanker vessels and other vessel types. The model structure is based on the steps provided in the Formal Safety Assessment (FSA) by the International Maritime Organization (IMO) and adapted into a Bayesian Network model. The results indicate that ship independent navigation and convoys are the operations with higher probability of oil spills. Minor spills are most probable, while major oil spills found very unlikely but possible. - Highlights: •A model to assess and manage the risk of winter navigation operations is proposed. •The risks of oil spills in winter navigation in the Gulf of Finland are analysed. •The model assesses and prioritizes actions to control the risk of the operations. •The model suggests navigational training as the most efficient risk control option.

  1. Thrills, Chills, Frissons, and Skin Orgasms: Toward an Integrative Model of Transcendent Psychophysiological Moments in Music

    Directory of Open Access Journals (Sweden)

    Lucas D. Harrison

    2014-07-01

    Full Text Available Music has a unique power to elicit moments of intense emotional and psychophysiological response. These moments – termed chills, thrills, frissons, etc. – are subjects of introspection and philosophical debate, as well as scientific study in music perception and cognition. The present article integrates the existing multidisciplinary literature in an attempt to define a comprehensive, testable, and ecologically valid model of transcendent psychophysiological moments in music.

  2. Regional-scale winter-spring temperature variability and chilling damage dynamics over the past two centuries in southeastern China

    Energy Technology Data Exchange (ETDEWEB)

    Duan, Jianping; Zhang, Qi-Bin; Lv, Lixin; Zhang, Chao [Institute of Botany, Chinese Academy of Sciences, State Key Laboratory of Vegetation and Environmental Change, Beijing (China)

    2012-08-15

    Winter-spring cold extreme is a kind of serious natural disaster for southeastern China. As such events are recorded in discrete documents, long and continuous records are required to understand their characteristics and driving forces. Here we report a regional-scale winter-spring (January-April) temperature reconstruction based on a tree-ring network of pine trees (Pinus massoniana) from five sampling sites over a large spatial scale (25-29 N, 111-115 E) in southeastern China. The regional tree-ring chronology explains 48.6% of the instrumental temperature variance during the period 1957-2008. The reconstruction shows six relatively warm intervals (i.e., {proportional_to}1849-1855, {proportional_to}1871-1888, {proportional_to}1909-1920, {proportional_to}1939-1944, {proportional_to}1958-1968, 1997-2007) and five cold intervals (i.e., {proportional_to}1860-1870, {proportional_to}1893-1908, {proportional_to}1925-1934, {proportional_to}1945-1957, {proportional_to}1982-1996) during 1849-2008. The last decade and the 1930s were the warmest and coldest decades, respectively, in the past 160 years. The composite analysis of 500-hPa geopotential height fields reveals that distinctly different circulation patterns occurred in the instrumental and pre-instrumental periods. The winter-spring cold extremes in southeastern China are associated with Ural-High ridge pattern for the instrumental period (1957-2008), whereas the cold extremes in pre-instrumental period (1871-1956) are associated with North circulation pattern. (orig.)

  3. Chilling injury

    African Journals Online (AJOL)

    ahar

    2013-12-18

    Dec 18, 2013 ... ROS avoidance genes play pivotal role in defense mechanism against chilling injury derived oxidative stress. ... Low temperature storage is a postharvest technology ..... crops is highly dependent on ethylene production and.

  4. Characterisation and modelling of defect formation in direct-chill cast AZ80 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mackie, D.; Robson, J.D.; Withers, P.J. [School of Materials, University of Manchester, Manchester M13 9PL (United Kingdom); Turski, M. [Magnesium Elektron UK, Rake Lane, Manchester, M27 8BF (United Kingdom)

    2015-06-15

    Wrought magnesium alloys for demanding structural applications require high quality defect free cast feedstock. The aim of this study was to first identify and characterise typical defects in direct chill cast magnesium–aluminium–zinc (AZ) alloy billet and then use modelling to understand the origins of these defects so they can be prevented. Defects were first located using ultrasonic inspection and were then characterised using X-ray computed tomography (XCT) and serial sectioning, establishing the presence of oxide films and intermetallic particles Al{sub 8}Mn{sub 5} in all defects. A model was developed to predict the flow patterns and growth kinetics of the intermetallic phases during casting, which influence the formation of defects. Simulation of the growth of the intermetallic particles demonstrated that precipitation from the liquid occurs in the mould. The combination of the entrained oxide films and intermetallic particles recirculates in the liquid metal and continues to grow, until large enough to settle, which is predicted to occur at the centre of the mould where the flow is the slowest. Based on these predictions, strategies to reduce the susceptibility to defect formation are suggested. - Highlights: • Casting defects in magnesium direct chill casting have been imaged and characterised in 3-dimensions. • The occurrences of co-located clusters of particles and oxide films have been characterised and explained. • A coupled model has been developed to help interpret the observed trend for defects located towards the centre of billets.

  5. Characterisation and modelling of defect formation in direct-chill cast AZ80 alloy

    International Nuclear Information System (INIS)

    Mackie, D.; Robson, J.D.; Withers, P.J.; Turski, M.

    2015-01-01

    Wrought magnesium alloys for demanding structural applications require high quality defect free cast feedstock. The aim of this study was to first identify and characterise typical defects in direct chill cast magnesium–aluminium–zinc (AZ) alloy billet and then use modelling to understand the origins of these defects so they can be prevented. Defects were first located using ultrasonic inspection and were then characterised using X-ray computed tomography (XCT) and serial sectioning, establishing the presence of oxide films and intermetallic particles Al 8 Mn 5 in all defects. A model was developed to predict the flow patterns and growth kinetics of the intermetallic phases during casting, which influence the formation of defects. Simulation of the growth of the intermetallic particles demonstrated that precipitation from the liquid occurs in the mould. The combination of the entrained oxide films and intermetallic particles recirculates in the liquid metal and continues to grow, until large enough to settle, which is predicted to occur at the centre of the mould where the flow is the slowest. Based on these predictions, strategies to reduce the susceptibility to defect formation are suggested. - Highlights: • Casting defects in magnesium direct chill casting have been imaged and characterised in 3-dimensions. • The occurrences of co-located clusters of particles and oxide films have been characterised and explained. • A coupled model has been developed to help interpret the observed trend for defects located towards the centre of billets

  6. Identification of chilling and heat requirements of cherry trees--a statistical approach.

    Science.gov (United States)

    Luedeling, Eike; Kunz, Achim; Blanke, Michael M

    2013-09-01

    Most trees from temperate climates require the accumulation of winter chill and subsequent heat during their dormant phase to resume growth and initiate flowering in the following spring. Global warming could reduce chill and hence hamper the cultivation of high-chill species such as cherries. Yet determining chilling and heat requirements requires large-scale controlled-forcing experiments, and estimates are thus often unavailable. Where long-term phenology datasets exist, partial least squares (PLS) regression can be used as an alternative, to determine climatic requirements statistically. Bloom dates of cherry cv. 'Schneiders späte Knorpelkirsche' trees in Klein-Altendorf, Germany, from 24 growing seasons were correlated with 11-day running means of daily mean temperature. Based on the output of the PLS regression, five candidate chilling periods ranging in length from 17 to 102 days, and one forcing phase of 66 days were delineated. Among three common chill models used to quantify chill, the Dynamic Model showed the lowest variation in chill, indicating that it may be more accurate than the Utah and Chilling Hours Models. Based on the longest candidate chilling phase with the earliest starting date, cv. 'Schneiders späte Knorpelkirsche' cherries at Bonn exhibited a chilling requirement of 68.6 ± 5.7 chill portions (or 1,375 ± 178 chilling hours or 1,410 ± 238 Utah chill units) and a heat requirement of 3,473 ± 1,236 growing degree hours. Closer investigation of the distinct chilling phases detected by PLS regression could contribute to our understanding of dormancy processes and thus help fruit and nut growers identify suitable tree cultivars for a future in which static climatic conditions can no longer be assumed. All procedures used in this study were bundled in an R package ('chillR') and are provided as Supplementary materials. The procedure was also applied to leaf emergence dates of walnut (cv. 'Payne') at Davis, California.

  7. Medical chilling device designed for hypothermic hydration graft storage system: Design, thermohydrodynamic modeling, and preliminary testing

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Jung Hwan [Hongik University, Seoul (Korea, Republic of)

    2015-02-15

    Hypothermic hydration graft storage is essential to reduce the metabolic demand of cells in vitro. The alleviated metabolic demands reduce the emergence rate of anaerobic metabolism generating adenosine triphosphate (ATP) energy that creates free radicals. The cessive free radicals can damage cells and tissues due to their highly oxidative power with molecules. Current cooling systems such as a conventional air cooling system and an ice pack system are inappropriate for chilling cell tissues in vitro because of inconvenience in use and inconsistent temperature sustainability caused by large size and progressive melting, respectively. Here, we develop a medical chilling device (MCD) for hypothermic hydration graft storage based on thermo-hydrodynamic modeling and thermal electric cooling technology. Our analysis of obtained hydrodynamic thermal behavior of the MCD revealed that the hypothermic condition of 4 .deg. C was continuously maintained, which increased the survival rates of cells in vitro test by reduced free radicals. The validated performance of the MCD promises future development of an optimal hypothermic hydration graft storage system designed for clinical use.

  8. A multiphysics and multiscale model for low frequency electromagnetic direct-chill casting

    International Nuclear Information System (INIS)

    Košnik, N; Guštin, A Z; Mavrič, B; Šarler, B

    2016-01-01

    Simulation and control of macrosegregation, deformation and grain size in low frequency electromagnetic (EM) direct-chill casting (LFEMC) is important for downstream processing. Respectively, a multiphysics and multiscale model is developed for solution of Lorentz force, temperature, velocity, concentration, deformation and grain structure of LFEMC processed aluminum alloys, with focus on axisymmetric billets. The mixture equations with lever rule, linearized phase diagram, and stationary thermoelastic solid phase are assumed, together with EM induction equation for the field imposed by the coil. Explicit diffuse approximate meshless solution procedure [1] is used for solving the EM field, and the explicit local radial basis function collocation method [2] is used for solving the coupled transport phenomena and thermomechanics fields. Pressure-velocity coupling is performed by the fractional step method [3]. The point automata method with modified KGT model is used to estimate the grain structure [4] in a post-processing mode. Thermal, mechanical, EM and grain structure outcomes of the model are demonstrated. A systematic study of the complicated influences of the process parameters can be investigated by the model, including intensity and frequency of the electromagnetic field. The meshless solution framework, with the implemented simplest physical models, will be further extended by including more sophisticated microsegregation and grain structure models, as well as a more realistic solid and solid-liquid phase rheology. (paper)

  9. Incorporating Yearly Derived Winter Wheat Maps Into Winter Wheat Yield Forecasting Model

    Science.gov (United States)

    Skakun, S.; Franch, B.; Roger, J.-C.; Vermote, E.; Becker-Reshef, I.; Justice, C.; Santamaría-Artigas, A.

    2016-01-01

    Wheat is one of the most important cereal crops in the world. Timely and accurate forecast of wheat yield and production at global scale is vital in implementing food security policy. Becker-Reshef et al. (2010) developed a generalized empirical model for forecasting winter wheat production using remote sensing data and official statistics. This model was implemented using static wheat maps. In this paper, we analyze the impact of incorporating yearly wheat masks into the forecasting model. We propose a new approach of producing in season winter wheat maps exploiting satellite data and official statistics on crop area only. Validation on independent data showed that the proposed approach reached 6% to 23% of omission error and 10% to 16% of commission error when mapping winter wheat 2-3 months before harvest. In general, we found a limited impact of using yearly winter wheat masks over a static mask for the study regions.

  10. STUDY OF CYLPEBS CHILLING

    Directory of Open Access Journals (Sweden)

    E. I. Marukovich

    2016-01-01

    Full Text Available Methods of increasing the shock resistance of cast-iron grinding bodies are researched. The models of heat transfer in the process of casting and shock-abrasive wear are presented. Tooling to produce experimental samples of milling bodies chilling(gravity die casting is manufactured, samples of cylpebs are produced.

  11. On numerical modeling of low-head direct chill ingot caster for magnesium alloy AZ31

    Directory of Open Access Journals (Sweden)

    Mainul Hasan

    2014-12-01

    Full Text Available A comprehensive 3D turbulent CFD study has been carried out to simulate a Low-Head (LH vertical Direct Chill (DC rolling ingot caster for the common magnesium alloy AZ31. The model used in this study takes into account the coupled laminar/turbulent melt flow and solidification aspects of the process and is based on the control-volume finite-difference approach. Following the aluminum/magnesium DC casting industrial practices, the LH mold is taken as 30 mm with a hot top of 60 mm. The previously verified in-house code has been modified to model the present casting process. Important quantitative results are obtained for four casting speeds, for three inlet melt pouring temperatures (superheats and for three metal-mold contact heat transfer coefficients for the steady state operational phase of the caster. The variable cooling water temperatures reported by the industry are considered for the primary and secondary cooling zones during the simulations. Specifically, the temperature and velocity fields, sump depth and sump profiles, mushy region thickness, solid shell thickness at the exit of the mold and axial temperature profiles at the center and at three strategic locations at the surface of the slab are presented and discussed.

  12. Process-scale modelling of microstructure in direct chill casting of aluminium alloys

    Science.gov (United States)

    Bedel, M.; Heyvaert, L.; Založnik, M.; Combeau, H.; Daloz, D.; Lesoult, G.

    2015-06-01

    The mechanical properties of an alloy being related to its microstructure, the understanding of the mechanisms responsible for the grain structure formation in direct chill casting is crucial. However, the grain size prediction by modelling is difficult since a variety of multi-scale coupled phenomena have to be considered. Nucleation and growth of the grains are interrelated, and the macroscopic transport phenomena such as the motion of grains and inoculant particles with the flow impact the nucleation-gowth competition. Thus we propose to study the grain size distribution of a 5182 alloy industrial scale slab of 510 mm thickness, both non-inoculated and inoculated with Al-3Ti-1B, for which experimental grain size measurements are available. We use a volume-averaged two-phase multi-scale model that describes nucleation from inoculant particles and grain growth, fully coupled with macroscopic transport phenomena: fluid flow induced by natural convection and solidification shrinkage, heat, mass and solute mass transport, grains and inoculant particles motion. We analyze the effect of liquid and grain motion as the effect of grain morphology on microstructure formation and we show in which extent those phenomena are responsible for the grain size distribution observed experimentally. The effect of the refiner level is also studied.

  13. Evaluation of olive flowering at low latitude sites in Argentina using a chilling requirement model

    Energy Technology Data Exchange (ETDEWEB)

    Aybar, V.E.; Melo-Abreu, J.P. de; Searles, P.S.; Matias, A.G.; Del Rio, C.; Caballero, C. M.; Rousseaux, M.C.

    2015-07-01

    Olive production has expanded significantly from the Mediterranean Basin into the New World over the last two decades. In some cases, cultivars of European origin have been introduced at a large commercial scale with little previous evaluation of potential productivity. The objective of this study was to evaluate whether a temperature-driven simulation model developed in the Mediterranean Basin to predict normal flowering occurrence and flowering date using cultivar-specific thermal requirements was suitable for the low latitude areas of Northwest Argentina. The model was validated at eight sites over several years and a wide elevation range (350–1200 m above mean sea level) for three cultivars (‘Arbequina’, ‘Frantoio’, ‘Leccino’) with potentially different chilling requirements. In ‘Arbequina’, normal flowering was observed at almost all sites and in all years, while normal flowering events in ‘Frantoio’ and ‘Leccino’ were uncommon. The model successfully predicted if flowering would be normal in 92% and 83% of the cases in ‘Arbequina’ and ‘Frantoio’, respectively, but was somewhat less successful in ‘Leccino’ (61%). When flowering occurred, the predicted flowering date was within ± 7 days of the observed date in 71% of the cases. Overall, the model results indicate that cultivar-specific simulation models may be used as an approximate tool to predict whether individual cultivars will be successful in new growing areas. In Northwest Argentina, the model could be used to identify cultivars to replace ‘Frantoio’ and ‘Leccino’ and to simulate global warming scenarios. (Author)

  14. Raw-appearing Restructured fish models made with Sodium alginate or Microbial transglutaminase and effect of chilled storage

    Directory of Open Access Journals (Sweden)

    Helena Moreno

    2013-03-01

    Full Text Available Restructuring by adding Sodium Alginate or Microbial Transglutaminase (MTGase using cold gelation technology make it possible to obtain many different raw products from minced and/or chopped fish muscle that are suitable for being used as the basis of new restructured products with different physicochemical properties and even different compositions. Special consideration must be given to their shelf-life and the changes that may take place during chilling, both in visual appearance and physicochemical properties. After chilled storage, the restructured models made with different muscular particle size and composition at low temperature (5 °C, it was observed that microbial growth limited the shelf-life to 7-14 days. Mechanical properties increased (p 0.05 was detected during storage.

  15. Insufficient Chilling Effects Vary among Boreal Tree Species and Chilling Duration

    Directory of Open Access Journals (Sweden)

    Rongzhou Man

    2017-08-01

    Full Text Available Insufficient chilling resulting from rising winter temperatures associated with climate warming has been an area of particular interest in boreal and temperate regions where a period of cool temperatures in fall and winter is required to break plant dormancy. In this study, we examined the budburst and growth of trembling aspen (Populus tremuloides Michx., balsam poplar (Populus balsamifera L., white birch (Betula papyrifera Marsh., black spruce (Picea mariana (Mill. B.S.P., white spruce (Picea glauca (Moench Voss, jack pine (Pinus banksiana Lamb., and lodgepole pine (Pinus contorta Dougl. ex. Loud. seedlings subjected to typical northern Ontario, Canada, spring conditions in climate chambers after different exposures to natural chilling. Results indicate that chilling requirements (cumulative weighted chilling hours differed substantially among the seven species, ranging from 300 to 500 h for spruce seedlings to more than 1100 h for trembling aspen and lodgepole pine. Only spruce seedlings had fulfilled their chilling requirements before December 31, whereas the other species continued chilling well into March and April. Species with lower chilling requirements needed more heat accumulation for budburst and vice versa. Insufficient chilling delayed budburst but only extremely restricted chilling hours (<400 resulted in abnormal budburst and growth, including reduced needle and shoot expansion, early budburst in lower crowns, and erratic budburst on lower stems and roots. Effects, however, depended on both the species’ chilling requirements and the chilling–heat relationship. Among the seven tree species examined, trembling aspen is most likely to be affected by reduced chilling accumulation possible under future climate scenarios, followed by balsam poplar, white birch, lodgepole pine, and jack pine. Black and white spruce are least likely to be affected by changes in chilling hours.

  16. Modeling winter moth Operophtera brumata egg phenology

    NARCIS (Netherlands)

    Salis, Lucia; Lof, Marjolein; Asch, van Margriet; Visser, Marcel E.

    2016-01-01

    Understanding the relationship between an insect's developmental rate and temperature is crucial to forecast insect phenology under climate change. In the winter moth Operophtera brumata timing of egg-hatching has severe fitness consequences on growth and reproduction as egg-hatching has to match

  17. Modeling Chilled-Water Storage System Components for Coupling to a Small Modular Reactor in a Nuclear Hybrid Energy System

    Science.gov (United States)

    Misenheimer, Corey Thomas

    The intermittency of wind and solar power puts strain on electric grids, often forcing carbonbased and nuclear sources of energy to operate in a load-follow mode. Operating nuclear reactors in a load-follow fashion is undesirable due to the associated thermal and mechanical stresses placed on the fuel and other reactor components. Various Thermal Energy Storage (TES) elements and ancillary energy applications can be coupled to nuclear (or renewable) power sources to help absorb grid instabilities caused by daily electric demand changes and renewable intermittency, thereby forming the basis of a candidate Nuclear Hybrid Energy System (NHES). During the warmer months of the year in many parts of the country, facility air-conditioning loads are significant contributors to the increase in the daily peak electric demand. Previous research demonstrated that a stratified chilled-water storage tank can displace peak cooling loads to off-peak hours. Based on these findings, the objective of this work is to evaluate the prospect of using a stratified chilled-water storage tank as a potential TES reservoir for a nuclear reactor in a NHES. This is accomplished by developing time-dependent models of chilled-water system components, including absorption chillers, cooling towers, a storage tank, and facility cooling loads appropriate for a large office space or college campus, as a callable FORTRAN subroutine. The resulting TES model is coupled to a high-fidelity mPower-sized Small Modular Reactor (SMR) Simulator, with the goal of utilizing excess reactor capacity to operate several sizable chillers in order to keep reactor power constant. Chilled-water production via single effect, lithium bromide (LiBr) absorption chillers is primarily examined in this study, although the use of electric chillers is briefly explored. Absorption chillers use hot water or low-pressure steam to drive an absorption-refrigeration cycle. The mathematical framework for a high-fidelity dynamic

  18. Determination of Chilling and Heat Requirement of Four Apricot Cultivars of Khorasan Razavi Province

    Directory of Open Access Journals (Sweden)

    zohreh hoshyar

    2017-02-01

    Full Text Available Introduction:Dormancy is one of the most important stages in the life cycle of temperate plants and plants are required to exit from it with supply of chill unit. Flowering is defined with chilling and heat requirement. Owing to low chilling requirement, blooming happens too early and cold temperatures produce an important loss of yield by frost. In temperate fruits, awareness of the need buds to avoid winter frost is one of the main objectives in breeding programs. Studies concerning chilling and heat requirements are thus of special interest in these species, being very important for the choice of parents in breeding programs to create superior varieties of winter and spring frost (late flowering and resistant cold provide. Utah is one of the most important model was introduced in 1974 by Richardson and colleagues. Effective temperature on cold storage in Utah model is 1/9-5/2. This is 6/1-9/12 in North Carolina and 8/1-9/13 in low chilling. Temperatures above 16 have negative effect on accumulation in Utah model. Later models were developed according to the Utah model that the Low chilling requirement (18 and the North Carolina (31 models are among them. Apricot (Prunus armeniaca L. is belonging to warm temperate regions and due to the lack of compatibility and apricot spring frost in Khorasan Razavi province, the identification of varieties and genotypes with high compatibility and high thermal and cooling requirements to reduce the risk of early frost and increase production efficiency, seems important. The purpose of this study was to determine the need for chilling and heat requirement in apricot cultivars. Material and methods: In this research, chilling and heating requirements of four local cultivars of apricot were evaluated under field and laboratory conditions. This experiment was conducted at agricultural research station Golmakan. A factorial (two-factor experiment was laid out in a completely randomized design with tree

  19. Modeling and analysis of chill and fill processes for the cryogenic storage and transfer engineering development unit tank

    Science.gov (United States)

    Hedayat, A.; Cartagena, W.; Majumdar, A. K.; LeClair, A. C.

    2016-03-01

    NASA's future missions may require long-term storage and transfer of cryogenic propellants. The Engineering Development Unit (EDU), a NASA in-house effort supported by both Marshall Space Flight Center (MSFC) and Glenn Research Center, is a cryogenic fluid management (CFM) test article that primarily serves as a manufacturing pathfinder and a risk reduction task for a future CFM payload. The EDU test article comprises a flight-like tank, internal components, insulation, and attachment struts. The EDU is designed to perform integrated passive thermal control performance testing with liquid hydrogen (LH2) in a test-like vacuum environment. A series of tests, with LH2 as a testing fluid, was conducted at Test Stand 300 at MSFC during the summer of 2014. The objective of this effort was to develop a thermal/fluid model for evaluating the thermodynamic behavior of the EDU tank during the chill and fill processes. The Generalized Fluid System Simulation Program, an MSFC in-house general-purpose computer program for flow network analysis, was utilized to model and simulate the chill and fill portion of the testing. The model contained the LH2 supply source, feed system, EDU tank, and vent system. The test setup, modeling description, and comparison of model predictions with the test data are presented.

  20. Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking

    Energy Technology Data Exchange (ETDEWEB)

    Das, Subodh K.

    2006-01-09

    A successful four-year project on the modeling and optimization of direct chill (DC) casting to reduce ingot cracking has been completed. The project involved close collaboration among private industries, national laboratories, and universities. During the four-year project, 16 quarterly meetings brought the industrial partners and the research team together for discussion of research results and research direction. The industrial partners provided guidance, facilities, and experience to the research team. The research team went to two industrial plants to measure temperature distributions in commercial 60,000-lb DC casting ingot. The collaborative research resulted in several major accomplishments or findings: (1) Surface cracks were shown to be a result of hot tearing rather than cold cracks, as was thought before this project. These cracks form on the surface of a DC cast ingot just above the impingement point of the secondary cooling water jets. The cracks form along dendrite and grain boundaries, where solute and impurity elements are highly segregated. This understanding led to the development of a new technique for determining the mechanical properties in the nonequilibrium mushy zone of alloys and to thermodynamic predictions of the hot tearing propensity of DC cast ingots. (2) The apparent heat transfer coefficient (HTC) at the ingot surface in the water cooling region during DC casting was determined on the basis of temperature measurements in commercial DC casting ingots and an inverse heat transfer analysis. HTCs were calculated as a function of temperature and time, and covered the different regimes of heat transfer expected during DC casting. The calculated values were extrapolated to include the effect of water flow rate. The calculated HTCs had a peak at around 200 C, corresponding to the high heat transfer rates during nucleate boiling, and the profile was consistent with similar data published in the literature. (3) A new method, termed the

  1. Effect of inlet geometry on macrosegregation during the direct chill casting of 7050 alloy billets: experiments and computer modelling

    International Nuclear Information System (INIS)

    Zhang, L; Miroux, A; Subroto, T; Katgerman, L; Eskin, D G

    2012-01-01

    Controlling macrosegregation is one of the major challenges in direct-chill (DC) casting of aluminium alloys. In this paper, the effect of the inlet geometry (which influences the melt distribution) on macrosegregation during the DC casting of 7050 alloy billets was studied experimentally and by using 2D computer modelling. The ALSIM model was used to determine the temperature and flow patterns during DC casting. The results from the computer simulations show that the sump profiles and flow patterns in the billet are strongly influenced by the melt flow distribution determined by the inlet geometry. These observations were correlated to the actual macrosegregation patterns found in the as-cast billets produced by having two different inlet geometries. The macrosegregation analysis presented here may assist in determining the critical parameters to consider for improving the casting of 7XXX aluminium alloys.

  2. Effect of inlet geometry on macrosegregation during the direct chill casting of 7050 alloy billets: experiments and computer modelling

    Science.gov (United States)

    Zhang, L.; Eskin, D. G.; Miroux, A.; Subroto, T.; Katgerman, L.

    2012-07-01

    Controlling macrosegregation is one of the major challenges in direct-chill (DC) casting of aluminium alloys. In this paper, the effect of the inlet geometry (which influences the melt distribution) on macrosegregation during the DC casting of 7050 alloy billets was studied experimentally and by using 2D computer modelling. The ALSIM model was used to determine the temperature and flow patterns during DC casting. The results from the computer simulations show that the sump profiles and flow patterns in the billet are strongly influenced by the melt flow distribution determined by the inlet geometry. These observations were correlated to the actual macrosegregation patterns found in the as-cast billets produced by having two different inlet geometries. The macrosegregation analysis presented here may assist in determining the critical parameters to consider for improving the casting of 7XXX aluminium alloys.

  3. Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking

    Energy Technology Data Exchange (ETDEWEB)

    Das, S.K.; Ningileri, S.; Long, Z.; Saito, K.; Khraisheh, M.; Hassan, M.H.; Kuwana, K.; Han, Q.; Viswanathan, S.; Sabau, A.S.; Clark, J.; Hyrn, J. (ANL)

    2006-08-15

    Approximately 68% of the aluminum produced in the United States is first cast into ingots prior to further processing into sheet, plate, extrusions, or foil. The direct chill (DC) semi-continuous casting process has been the mainstay of the aluminum industry for the production of ingots due largely to its robust nature and relative simplicity. Though the basic process of DC casting is in principle straightforward, the interaction of process parameters with heat extraction, microstructural evolution, and development of solidification stresses is too complex to analyze by intuition or practical experience. One issue in DC casting is the formation of stress cracks [1-15]. In particular, the move toward larger ingot cross-sections, the use of higher casting speeds, and an ever-increasing array of mold technologies have increased industry efficiencies but have made it more difficult to predict the occurrence of stress crack defects. The Aluminum Industry Technology Roadmap [16] has recognized the challenges inherent in the DC casting process and the control of stress cracks and selected the development of 'fundamental information on solidification of alloys to predict microstructure, surface properties, and stresses and strains' as a high-priority research need, and the 'lack of understanding of mechanisms of cracking as a function of alloy' and 'insufficient understanding of the aluminum solidification process', which is 'difficult to model', as technology barriers in aluminum casting processes. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks from the current level of 5% to 2%. Decreasing stress crack incidence is important for improving product quality and consistency as well as for saving resources and energy, since considerable amounts of cast metal could be saved by eliminating ingot cracking, by reducing the scalping thickness of

  4. Modelling the effect of coating on the stresses and microstructure evolution in chill casting of wind turbine main shafts

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Thorborg, J.; Hattel, Jesper Henri

    2017-01-01

    The purpose of the present work is to quantify the effect of the inside coating on chills for casting of large wind turbine main shafts with respect to the evolution of internal stresses. These are known to affect the lifetime of the chills, and this is a major cost for the foundries today. Simul......, it is concluded that the material quality obtained from casting the main shafts in chills (and hence the performance of the part) is still much better than for sand casting, even though a very thick layer of coating is applied. Copyright © 2017 John Wiley & Sons, Ltd....... in the simulations. The outcome is validated by comparisons with samples taken out from a critical region of main shafts cast in sand and in chills. The results reveal minor reductions in the maximum principal stresses on the inner and outer surfaces of the chill of 3.1% and 18.5%, respectively, from changing...

  5. Chilled beam application guidebook

    CERN Document Server

    Butler, David; Gräslund, Jonas; Hogeling, Jaap; Lund Kristiansen, Erik; Reinikanen, Mika; Svensson, Gunnar

    2007-01-01

    Chilled beam systems are primarily used for cooling and ventilation in spaces, which appreciate good indoor environmental quality and individual space control. Active chilled beams are connected to the ventilation ductwork, high temperature cold water, and when desired, low temperature hot water system. Primary air supply induces room air to be recirculated through the heat exchanger of the chilled beam. In order to cool or heat the room either cold or warm water is cycled through the heat exchanger.

  6. Representation of Northern Hemisphere winter storm tracks in climate models

    Energy Technology Data Exchange (ETDEWEB)

    Greeves, C.Z.; Pope, V.D.; Stratton, R.A.; Martin, G.M. [Met Office Hadley Centre for Climate Prediction and Research, Exeter (United Kingdom)

    2007-06-15

    Northern Hemisphere winter storm tracks are a key element of the winter weather and climate at mid-latitudes. Before projections of climate change are made for these regions, it is necessary to be sure that climate models are able to reproduce the main features of observed storm tracks. The simulated storm tracks are assessed for a variety of Hadley Centre models and are shown to be well modelled on the whole. The atmosphere-only model with the semi-Lagrangian dynamical core produces generally more realistic storm tracks than the model with the Eulerian dynamical core, provided the horizontal resolution is high enough. The two models respond in different ways to changes in horizontal resolution: the model with the semi-Lagrangian dynamical core has much reduced frequency and strength of cyclonic features at lower resolution due to reduced transient eddy kinetic energy. The model with Eulerian dynamical core displays much smaller changes in frequency and strength of features with changes in horizontal resolution, but the location of the storm tracks as well as secondary development are sensitive to resolution. Coupling the atmosphere-only model (with semi-Lagrangian dynamical core) to an ocean model seems to affect the storm tracks largely via errors in the tropical representation. For instance a cold SST bias in the Pacific and a lack of ENSO variability lead to large changes in the Pacific storm track. Extratropical SST biases appear to have a more localised effect on the storm tracks. (orig.)

  7. Application of a Pore Fraction Hot Tearing Model to Directionally Solidified and Direct Chill Cast Aluminum Alloys

    Science.gov (United States)

    Dou, Ruifeng; Phillion, A. B.

    2016-08-01

    Hot tearing susceptibility is commonly assessed using a pressure drop equation in the mushy zone that includes the effects of both tensile deformation perpendicular to the thermal gradient as well as shrinkage feeding. In this study, a Pore Fraction hot tearing model, recently developed by Monroe and Beckermann (JOM 66:1439-1445, 2014), is extended to additionally include the effect of strain rate parallel to the thermal gradient. The deformation and shrinkage pore fractions are obtained on the basis of the dimensionless Niyama criterion and a scaling variable method. First, the model is applied to the binary Al-Cu system under conditions of directional solidification. It is shown that for the same Niyama criterion, a decrease in the cooling rate increases both the deformation and shrinkage pore fractions because of an increase in the time spent in the brittle temperature region. Second, the model is applied to the industrial aluminum alloy AA5182 as part of a finite element simulation of the Direct Chill (DC) casting process. It is shown that an increase in the casting speed during DC casting increases the deformation and shrinkage pore fractions, causing the maximum point of pore fraction to move towards the base of the casting. These results demonstrate that including the strain rate parallel to the thermal gradient significantly improves the predictive quality of hot tearing criteria based on the pressure drop equation.

  8. Modelling-based identification of factors influencing campylobacters in chicken broiler houses and on carcasses sampled after processing and chilling.

    Science.gov (United States)

    Hutchison, M L; Taylor, M J; Tchòrzewska, M A; Ford, G; Madden, R H; Knowles, T G

    2017-05-01

    To identify production and processing practices that might reduce Campylobacter numbers contaminating chicken broiler carcasses. The numbers of campylobacters were determined on carcass neck skins after processing or in broiler house litter samples. Supplementary information that described farm layouts, farming conditions for individual flocks, the slaughterhouse layouts and operating conditions inside plants was collected, matched with each Campylobacter test result. Statistical models predicting the numbers of campylobacters on neck skins and in litter were constructed. Carcass microbial contamination was more strongly influenced by on-farm production practices compared with slaughterhouse activities. We observed correlations between the chilling, washing and defeathering stages of processing and the numbers of campylobacters on carcasses. There were factors on farm that also correlated with numbers of campylobacters in litter. These included bird gender, the exclusion of dogs from houses, beetle presence in the house litter and the materials used to construct the house frame. Changes in farming practices have greater potential for reducing chicken carcass microbial contamination compared with processing interventions. Routine commercial practices were identified that were correlated with lowered numbers of campylobacters. Consequently, these practices are likely to be both cost-effective and suitable for adoption into established farms and commercial processing. © 2017 The Authors. Journal of Applied Microbiology published by John Wiley & Sons Ltd on behalf of Society for Applied Microbiology.

  9. Clustering of European winter storms: A multi-model perspective

    Science.gov (United States)

    Renggli, Dominik; Buettner, Annemarie; Scherb, Anke; Straub, Daniel; Zimmerli, Peter

    2016-04-01

    The storm series over Europe in 1990 (Daria, Vivian, Wiebke, Herta) and 1999 (Anatol, Lothar, Martin) are very well known. Such clusters of severe events strongly affect the seasonally accumulated damage statistics. The (re)insurance industry has quantified clustering by using distribution assumptions deduced from the historical storm activity of the last 30 to 40 years. The use of storm series simulated by climate models has only started recently. Climate model runs can potentially represent 100s to 1000s of years, allowing a more detailed quantification of clustering than the history of the last few decades. However, it is unknown how sensitive the representation of clustering is to systematic biases. Using a multi-model ensemble allows quantifying that uncertainty. This work uses CMIP5 decadal ensemble hindcasts to study clustering of European winter storms from a multi-model perspective. An objective identification algorithm extracts winter storms (September to April) in the gridded 6-hourly wind data. Since the skill of European storm predictions is very limited on the decadal scale, the different hindcast runs are interpreted as independent realizations. As a consequence, the available hindcast ensemble represents several 1000 simulated storm seasons. The seasonal clustering of winter storms is quantified using the dispersion coefficient. The benchmark for the decadal prediction models is the 20th Century Reanalysis. The decadal prediction models are able to reproduce typical features of the clustering characteristics observed in the reanalysis data. Clustering occurs in all analyzed models over the North Atlantic and European region, in particular over Great Britain and Scandinavia as well as over Iberia (i.e. the exit regions of the North Atlantic storm track). Clustering is generally weaker in the models compared to reanalysis, although the differences between different models are substantial. In contrast to existing studies, clustering is driven by weak

  10. Chilling Out With Colds

    Science.gov (United States)

    ... and use the time to read, listen to music, or watch a movie. In other words, chill out and you might prevent a cold! Reviewed by: Patricia ... Policy Permissions Guidelines Privacy Policy & Terms of Use Notice ...

  11. Chilling outweighs photoperiod in preventing precocious spring development.

    Science.gov (United States)

    Laube, Julia; Sparks, Tim H; Estrella, Nicole; Höfler, Josef; Ankerst, Donna P; Menzel, Annette

    2014-01-01

    It is well known that increased spring temperatures cause earlier onset dates of leaf unfolding and flowering. However, a temperature increase in winter may be associated with delayed development when species' chilling requirements are not fulfilled. Furthermore, photosensitivity is supposed to interfere with temperature triggers. To date, neither the relative importance nor possible interactions of these three factors have been elucidated. In this study, we present a multispecies climate chamber experiment to test the effects of chilling and photoperiod on the spring phenology of 36 woody species. Several hypotheses regarding their variation with species traits (successional strategy, floristic status, climate of their native range) were tested. Long photoperiods advanced budburst for one-third of the studied species, but magnitudes of these effects were generally minor. In contrast to prior hypotheses, photosensitive responses were not restricted to climax or oceanic species. Increased chilling length advanced budburst for almost all species; its effect greatly exceeding that of photoperiod. Moreover, we suggest that photosensitivity and chilling effects have to be rigorously disentangled, as the response to photoperiod was restricted to individuals that had not been fully chilled. The results indicate that temperature requirements and successional strategy are linked, with climax species having higher chilling and forcing requirements than pioneer species. Temperature requirements of invasive species closely matched those of native species, suggesting that high phenological concordance is a prerequisite for successful establishment. Lack of chilling not only led to a considerable delay in budburst but also caused substantial changes in the chronological order of species' budburst. The results reveal that increased winter temperatures might impact forest ecosystems more than formerly assumed. Species with lower chilling requirements, such as pioneer or invasive

  12. Chilling injury in mangoes

    NARCIS (Netherlands)

    Arafat, L.A.E.T.

    2005-01-01

    At present, the value and production quantity of mango fruits are increasing worldwide. Many studies emphasize how chilling injury phenomena affect the quality of tropical fruits, such as mango, during postharvest handling, transport, and storage. Since mango is one of the most favored and popular

  13. ChillFish

    DEFF Research Database (Denmark)

    Sonne, Tobias; Jensen, Mads Møller

    2016-01-01

    Breathing exercises can help children with ADHD control their stress level, but it can be hard for a child to sustain attention throughout such an exercise. In this paper, we present ChillFish, a breath-controlled biofeedback game designed in collaboration with ADHD professionals to investigate...... the possibilities of combining breathing exercises and game design. Based on a pilot study with 16 adults, we found that playing ChillFish had a positive effect, helping the participants to reach a relaxed state similar to the one offered by traditional breathing exercises. Further, we analyze the opportunities...... and challenges of creating a tangible respiration-based controller and use it as a core game mechanic. Finally, we discuss the challenge of balancing engagement and relaxation in physically controlled games for children with ADHD in order to make a game that can be calming and still sustain their attention....

  14. Irradiation of chilled lamb

    International Nuclear Information System (INIS)

    Roberts, P.B.

    1985-04-01

    Chilled, vacuum-packed New Zealand lamb loins have been irradiated at doses between 1-8 kGy. The report outlines the methods used and provides dosimetry details. An appendix summarises the results of a taste trial conducted on the irradiated meat by the Meat Industry Research Institute of New Zealand. This showed that, even at 1 kGy, detectable flavours were induced by the radiation treatment

  15. Winter wheat response to irrigation, nitrogen fertilization, and cold hazards in the Community Land Model 5

    Science.gov (United States)

    Lu, Y.

    2017-12-01

    Winter wheat is a staple crop for global food security, and is the dominant vegetation cover for a significant fraction of earth's croplands. As such, it plays an important role in soil carbon balance, and land-atmosphere interactions in these key regions. Accurate simulation of winter wheat growth is not only crucial for future yield prediction under changing climate, but also for understanding the energy and water cycles for winter wheat dominated regions. A winter wheat growth model has been developed in the Community Land Model 4.5 (CLM4.5), but its responses to irrigation and nitrogen fertilization have not been validated. In this study, I will validate winter wheat growth response to irrigation and nitrogen fertilization at five winter wheat field sites (TXLU, KSMA, NESA, NDMA, and ABLE) in North America, which were originally designed to understand winter wheat response to nitrogen fertilization and water treatments (4 nitrogen levels and 3 irrigation regimes). I also plan to further update the linkages between winter wheat yield and cold hazards. The previous cold damage function only indirectly affects yield through reduction on leaf area index (LAI) and hence photosynthesis, such approach could sometimes produce an unwanted higher yield when the reduced LAI saved more nutrient in the grain fill stage.

  16. Conteúdo de carboidratos em gemas e ramos de macieira durante o outono e inverno em região de baixa ocorrência de frio Carbohydrate content in buds and stems of apple trees during autumn and winter in a region of low chill occurence

    Directory of Open Access Journals (Sweden)

    Ruy Inacio Neiva de Carvalho

    2004-08-01

    Full Text Available Objetivou-se quantificar o teor de carboidratos em gemas e ramos de um ano de macieira cv. 'Imperial Gala', com ou sem frio suplementar, durante o outono e inverno, cultivada em região de baixa ocorrência de frio. Os ramos foram coletados em Porto Amazonas-PR, em intervalos de 21 dias, de abril a agosto (19-04, 10-05, 31-05, 21-06, 12-07, 02-08 e 23-08, e receberam ou não tratamento com frio suplementar de 1.440 horas, à temperatura de 4 a 7° C. As análises de carboidratos foram realizadas em gemas e porções de ramos adjacentes às mesmas. Os carboidratos solúveis totais foram determinados pelo método do fenol-sulfúrico, realizando-se a leitura por espectrofotometria (absorbância a 490 nm. Os carboidratos insolúveis totais foram estimados pelo rendimento da fração de tecido vegetal insolúvel em álcool e solúvel em álcali, após liofilização. Os carboidratos solúveis mais os insolúveis representaram de 13,8 a 20,2 % da matéria seca de gemas e 9,9 a 15,3 % da matéria seca de ramos de um ano de macieira. Em gemas de macieira, houve maior porcentagem de carboidratos solúveis na entrada em dormência e maior porcentagem de carboidratos insolúveis na dormência mais intensa. A ocorrência de frio precoce antecipou o acúmulo de carboidratos insolúveis nas gemas enquanto o frio, durante a endodormência, promoveu o acúmulo de carboidratos solúveis. Houve aumento do conteúdo de carboidratos solúveis em ramos com o desenvolvimento da endodormência enquanto as variações do conteúdo de carboidratos insolúveis não foram significativas.This work aimed at evaluating the carbohydrate content of one year old buds and stems of apple trees cv. 'Imperial Gala' with or without supplementary chill during autumn and winter, cultivated in a region of low chill occurence. The stems were collected in Porto Amazonas, Parana State, Brazil, at intervals of 21 days from April to August (04/19, 05/10, 05/31, 06/21, 07/12, 08/02 and 08

  17. Terral De Vicuna, a Foehnlike Wind in Semiarid Northern Chile: Meteorological Aspects and Implications for the Fulfillment of Chill Requirements in Deciduous Fruit Trees

    Science.gov (United States)

    Montes, Carlo; Rutllant, Jose A.; Aguirre, Anita; Bascunan-Godoy, Luisa; Julia, Cristobal

    2016-01-01

    The terral de Vicuña is a warm and dry wind that flows down the Elqui Valley in north-central Chile typically at dawn and early morning. Given that most terral episodes occur in austral winter when chill accumulation by deciduous fruit trees proceeds, negative effects on agriculture may be expected. During 11 (2004-14) winters a meteorological characterization of terral winds and the assessment of their impact on chill accumulation, by the modified Utah Model and the Dynamic Model, were performed. Within this period, 67 terral days (TD) were identified as those in which nighttime to early morning wind direction and speed, air temperature, and relative humidity reached defined thresholds on an hourly basis (terral hours). Most frequent TD featured 6-9 consecutive terral hours; duration is considered here as a proxy for their intensity. Synoptic-scale meteorological analysis shows that 65% of moderate and strong terral events develop as a cold, migratory anticyclone drifts poleward of the study area, coinciding with the onset of a midtropospheric ridge over central Chile, bringing southwest winds on top of the Andes (approximately 500-hPa level). The remaining 35% are either associated with 500-hPa easterlies (foehn like), with prefrontal conditions ahead of a trough driving northwest 500-hPa winds, or with transitional 500-hPa westerlies.Assessments of chill accumulation during TD show that, although present average and cold winter conditions do not represent a major TD hazard to local agriculture, lower chill accumulation associated with anomalously high nocturnal temperatures could be significantly more important during present and future warmer winters.

  18. Development of a model system to identify differences in spring and winter oat.

    Science.gov (United States)

    Chawade, Aakash; Lindén, Pernilla; Bräutigam, Marcus; Jonsson, Rickard; Jonsson, Anders; Moritz, Thomas; Olsson, Olof

    2012-01-01

    Our long-term goal is to develop a Swedish winter oat (Avena sativa). To identify molecular differences that correlate with winter hardiness, a winter oat model comprising of both non-hardy spring lines and winter hardy lines is needed. To achieve this, we selected 294 oat breeding lines, originating from various Russian, German, and American winter oat breeding programs and tested them in the field in south- and western Sweden. By assaying for winter survival and agricultural properties during four consecutive seasons, we identified 14 breeding lines of different origins that not only survived the winter but also were agronomically better than the rest. Laboratory tests including electrolytic leakage, controlled crown freezing assay, expression analysis of the AsVrn1 gene and monitoring of flowering time suggested that the American lines had the highest freezing tolerance, although the German lines performed better in the field. Finally, six lines constituting the two most freezing tolerant lines, two intermediate lines and two spring cultivars were chosen to build a winter oat model system. Metabolic profiling of non-acclimated and cold acclimated leaf tissue samples isolated from the six selected lines revealed differential expression patterns of 245 metabolites including several sugars, amino acids, organic acids and 181 hitherto unknown metabolites. The expression patterns of 107 metabolites showed significant interactions with either a cultivar or a time-point. Further identification, characterisation and validation of these metabolites will lead to an increased understanding of the cold acclimation process in oats. Furthermore, by using the winter oat model system, differential sequencing of crown mRNA populations would lead to identification of various biomarkers to facilitate winter oat breeding.

  19. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    Science.gov (United States)

    Yeo, In-Young; Lee, Sangchui; Sadeghi, Ali M.; Beeson, Peter C.; Hively, W. Dean; McCarty, Greg W.; Lang, Megan W.

    2013-01-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha−1, but it decreased to 4.6–10.1 kg ha−1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha−1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils

  20. Adaptive temperature regulation in the little bird in winter: predictions from a stochastic dynamic programming model.

    Science.gov (United States)

    Brodin, Anders; Nilsson, Jan-Åke; Nord, Andreas

    2017-09-01

    Several species of small birds are resident in boreal forests where environmental temperatures can be -20 to -30 °C, or even lower, in winter. As winter days are short, and food is scarce, winter survival is a challenge for small endothermic animals. A bird of this size will have to gain almost 10% of its lean body mass in fat every day to sustain overnight metabolism. Birds such as parids (titmice and chickadees) can use facultative hypothermia, a process in which body temperature is actively down-regulated to a specific level, to reduce heat loss and thus save energy. During cold winter nights, these birds may decrease body temperature from the normal from 42 ° down to 35 °C, or even lower in some species. However, birds are unable to move in this deep hypothermic state, making it a risky strategy if predators are around. Why, then, do small northern birds enter a potentially dangerous physiological state for a relatively small reduction in energy expenditure? We used stochastic dynamic programming to investigate this. Our model suggests that the use of nocturnal hypothermia at night is paramount in these biomes, as it would increase winter survival for a small northern bird by 58% over a winter of 100 days. Our model also explains the phenomenon known as winter fattening, and its relationship to thermoregulation, in northern birds.

  1. Is Hosting the Games Enough to Win? A predictive economic model of medal wins at 2014 Winter Olympics

    OpenAIRE

    Wladimir Andreff

    2012-01-01

    An econometric model which has first been estimated on medal wins at Summer Olympics and has predicted 88% of medal distribution at Beijing Games 2008, is revisited for Winter Olympics. After changing some variables to take into account the winter sports specificity, the model is estimated again on all Winter Games since 1964.Then it is used to predict (forecast) the medal distribution per country at the 2014 Sochi Winter Olympics.

  2. Modeling winter precipitation over the Juneau Icefield, Alaska, using a linear model of orographic precipitation

    Science.gov (United States)

    Roth, Aurora; Hock, Regine; Schuler, Thomas V.; Bieniek, Peter A.; Pelto, Mauri; Aschwanden, Andy

    2018-03-01

    Assessing and modeling precipitation in mountainous areas remains a major challenge in glacier mass balance modeling. Observations are typically scarce and reanalysis data and similar climate products are too coarse to accurately capture orographic effects. Here we use the linear theory of orographic precipitation model (LT model) to downscale winter precipitation from a regional climate model over the Juneau Icefield, one of the largest ice masses in North America (>4000 km2), for the period 1979-2013. The LT model is physically-based yet computationally efficient, combining airflow dynamics and simple cloud microphysics. The resulting 1 km resolution precipitation fields show substantially reduced precipitation on the northeastern portion of the icefield compared to the southwestern side, a pattern that is not well captured in the coarse resolution (20 km) WRF data. Net snow accumulation derived from the LT model precipitation agrees well with point observations across the icefield. To investigate the robustness of the LT model results, we perform a series of sensitivity experiments varying hydrometeor fall speeds, the horizontal resolution of the underlying grid, and the source of the meteorological forcing data. The resulting normalized spatial precipitation pattern is similar for all sensitivity experiments, but local precipitation amounts vary strongly, with greatest sensitivity to variations in snow fall speed. Results indicate that the LT model has great potential to provide improved spatial patterns of winter precipitation for glacier mass balance modeling purposes in complex terrain, but ground observations are necessary to constrain model parameters to match total amounts.

  3. An Evaluation of Mesoscale Model Based Model Output Statistics (MOS) During the 2002 Olympic and Paralympic Winter Games

    National Research Council Canada - National Science Library

    Hart, Kenneth

    2003-01-01

    The skill of a mesoscale model based Model Output Statistics (MOS) system that provided hourly forecasts for 18 sites over northern Utah during the 2002 Winter Olympic and Paralympic Games is evaluated...

  4. Induction of chilling tolerance in wheat during germination by pre-soaking seed with nitric oxide and gibberellin

    DEFF Research Database (Denmark)

    Li, Xiangnan; Jiang, Haidong; Liu, Fulai

    2013-01-01

    Chilling depresses seed germination and seedling establishment, and is one major constraint to grain yield formation in late sown winter wheat. Seeds of winter wheat (Triticum aestivum L.) were separately pre-soaked with sodium nitroprusside (SNP, as nitric oxide donor) and Gibberellic acid (GA3...... by exogenous NO and GA3 as a result of improved seed germination and maintenance of better reactive oxygen species homeostasis in seedling growing under chilling temperatures. It is indicated that exogenous NO was more effective than GA3 in alleviating chilling stress during seed germination and seedling...

  5. Comparing Model Ozone Loss during the SOLVE and SOLVE-2 Winters

    Science.gov (United States)

    Drdla, K.

    2003-01-01

    Model simulations have been used to analyze the factors influencing ozone loss during the 1999-2000 and 2002-2003 js. For both winters, the evolution of the Arctic vortex from November to April has been simulated using a trajectory-based microphysical and photochemical model. Extensive PSC formation and strong ozone depletion are evident in both winters. However, the ozone loss begins earlier in the 2002-2003 winter, with significant ozone depletion by early January. Analysis of the model results shows that during December 2002 not only cold temperatures but also the vortex structure was critical, allowing PSC-processed air parcels to experience significant solar exposure. The resultant ozone loss can be differentiated from ozone loss that occurs in the springtime, in particular because of the continued exposure to PSCs. For example, chlorine reactivation by the PSCs causes ozone loss to be insensitive to denitrification. Therefore, diagnosing the extent of ozone loss early in the winter is critical In understanding the overall winter-long ozone depletion.

  6. Spatially explicit modeling of conflict zones between wildlife and snow sports: prioritizing areas for winter refuges.

    Science.gov (United States)

    Braunisch, Veronika; Patthey, Patrick; Arlettaz, Raphaël

    2011-04-01

    Outdoor winter recreation exerts an increasing pressure upon mountain ecosystems, with unpredictable, free-ranging activities (e.g., ski mountaineering, snowboarding, and snowshoeing) representing a major source of stress for wildlife. Mitigating anthropogenic disturbance requires the spatially explicit prediction of the interference between the activities of humans and wildlife. We applied spatial modeling to localize conflict zones between wintering Black Grouse (Tetrao tetrix), a declining species of Alpine timberline ecosystems, and two free-ranging winter sports (off-piste skiing [including snow-boarding] and snowshoeing). Track data (snow-sports and birds' traces) obtained from aerial photographs taken over a 585-km transect running along the timberline, implemented within a maximum entropy model, were used to predict the occurrence of snow sports and Black Grouse as a function of landscape characteristics. By modeling Black Grouse presence in the theoretical absence of free-ranging activities and ski infrastructure, we first estimated the amount of habitat reduction caused by these two factors. The models were then extrapolated to the altitudinal range occupied by Black Grouse, while the spatial extent and intensity of potential conflict were assessed by calculating the probability of human-wildlife co-occurrence. The two snow-sports showed different distribution patterns. Skiers' occurrence was mainly determined by ski-lift presence and a smooth terrain, while snowshoers' occurrence was linked to hiking or skiing routes and moderate slopes. Wintering Black Grouse avoided ski lifts and areas frequented by free-ranging snow sports. According to the models, Black Grouse have faced a substantial reduction of suitable wintering habitat along the timberline transect: 12% due to ski infrastructure and another 16% when adding free-ranging activities. Extrapolating the models over the whole study area results in an overall habitat loss due to ski infrastructure of

  7. Winter precipitation characteristics in western US related to atmospheric river landfalls: observations and model evaluations

    Science.gov (United States)

    Kim, J.; Guan, B.; Waliser, D. E.; Ferraro, R. D.; Case, J. L.; Iguchi, T.; Kemp, E.; Putman, W.; Wang, W.; Wu, D.; Tian, B.

    2018-01-01

    Winter precipitation (PR) characteristics in western United States (WUS) related to atmospheric river (AR) landfalls are examined using the observation-based PRISM data. The observed AR-related precipitation characteristics are in turn used to evaluate model precipitation data from the NASA MERRA2 reanalysis and from seven dynamical downscaling simulations driven by the MERRA2. Multiple metrics including mean bias, Taylor diagram, and two skill scores are used to measure model performance for three climatological sub-regions in WUS, Pacific Northwest (PNW), Pacific Southwest (PSW) and Great Basin (GB). All model data well represent the winter-mean PR with spatial pattern correlations of 0.8 or higher with PRISM for the three sub-regions. Higher spatial resolutions and/or the use of spectral nudging generally yield higher skill scores in simulating the geographical distribution of PR for the entire winter. The PRISM data shows that the AR-related fraction of winter PR and associated daily PR PDFs in each region vary strongly for landfall locations; AR landfalls in the northern WUS coast (NC) affect mostly PNW while those in the southern WUS coast (SC) affect both PSW and GB. NC (SC) landfalls increase the frequency of heavy PR in PNW (PSW and GB) but reduce it in PSW (PNW). All model data reasonably represent these observed variations in the AR-related winter PR fractions and the daily PR PDFs according to AR landfall locations. However, unlike for the entire winter period, no systematic effects of resolution and/or spectral nudging are identified in these AR-related PR characteristics. Dynamical downscaling in this study generally yield positive added values to the MERRA2 PR in the AR-related PR fraction for most sub-regions and landfall locations, most noticeably for PSW by NU-WRF. The downscaling also generate positive added value in p95 for PNW, but negative values for PSW and GB due to overestimation of heavy precipitation events.

  8. A model of peripheral microvascular injury: irreversible caudal necrosis induced in carrageenan-inflamed rats treated with anti-inflammatory drugs and mild chilling: a pluricausal thrombo-haemorrhagic phenomenon.

    Science.gov (United States)

    Whitehouse, M W; Rainsford, K D

    1985-01-01

    A florid tail injury was observed in carrageenan-inflamed rats previously treated with acidic non-steroidal anti-inflammatory (NSAI) drugs to suppress paw inflammation and then exposed to mild chilling (7-10 degrees C for 10-16 h). All three treatments, i.e. NSAI drug + carrageenan paw oedema + mild chilling treatment, were required for the development of this condition. Histological observations suggest that the tissue necrosis was initiated by a primary disturbance of the peripheral vasculature. The possible involvement of suppressed prostaglandin (PG) production in the aetiology of this condition is indicated by the fact that it was totally reversed by prior treatment with PGE2. This appears to be a classical pluricausal thrombohaemorrhagic phenomenon (of Selye), with cold-stress being the sensitizer and carrageenan and NSAI drugs being the challenger. The possibilities are considered of employing this tail injury model as a convenient method of developing drugs to control microvascular disturbances in man.

  9. From Cyclone Tracks to the Costs of European Winter Storms: A Probabilistic Loss Assessment Model

    Science.gov (United States)

    Orwig, K.; Renggli, D.; Corti, T.; Reese, S.; Wueest, M.; Viktor, E.; Zimmerli, P.

    2014-12-01

    European winter storms cause billions of dollars of insured losses every year. Therefore, it is essential to understand potential impacts of future events, and the role reinsurance can play to mitigate the losses. The authors will present an overview on natural catastrophe risk assessment modeling in the reinsurance industry, and the development of a new innovative approach for modeling the risk associated with European winter storms.The new innovative approach includes the development of physically meaningful probabilistic (i.e. simulated) events for European winter storm loss assessment. The meteorological hazard component of the new model is based on cyclone and windstorm tracks identified in the 20thCentury Reanalysis data. The knowledge of the evolution of winter storms both in time and space allows the physically meaningful perturbation of historical event properties (e.g. track, intensity, etc.). The perturbation includes a random element but also takes the local climatology and the evolution of the historical event into account.The low-resolution wind footprints taken from the 20thCentury Reanalysis are processed by a statistical-dynamical downscaling to generate high-resolution footprints for both the simulated and historical events. Downscaling transfer functions are generated using ENSEMBLES regional climate model data. The result is a set of reliable probabilistic events representing thousands of years. The event set is then combined with country and site-specific vulnerability functions and detailed market- or client-specific information to compute annual expected losses.

  10. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    Science.gov (United States)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2014-12-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality at the watershed scale (~ 50 km2) and to identify critical source areas of high nitrate export. A physically based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data to simulate hydrological processes and agricultural nutrient cycling over the period of 1990-2000. To accurately simulate winter cover crop biomass in relation to growing conditions, a new approach was developed to further calibrate plant growth parameters that control the leaf area development curve using multitemporal satellite-based measurements of species-specific winter cover crop performance. Multiple SWAT scenarios were developed to obtain baseline information on nitrate loading without winter cover crops and to investigate how nitrate loading could change under different winter cover crop planting scenarios, including different species, planting dates, and implementation areas. The simulation results indicate that winter cover crops have a negligible impact on the water budget but significantly reduce nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading from agricultural lands was approximately 14 kg ha-1, but decreased to 4.6-10.1 kg ha-1 with cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was the most effective species, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of cover crops (~ 30

  11. Ruoanvalmistuspaperi Cook and chill prosessissa

    OpenAIRE

    Sarjohalme, Sirkka; Helin, Inga

    2012-01-01

    Opinnäytetyö lähti liikkeelle opinnäytetyön tilaajan, Metsä Tissuen, toiveesta tutkia Cook and chill -ruoanvalmistuspaperin soveltuvuutta Cook and chill -tuotantotapaan ammattikeittiöissä. Uudet toimintamenetelmät eroavat perinteisistä menetelmistä käytännössä näkyvimmin siinä, että ruoanvalmistus ei ole sidottu tarjoilupaikkaan ja ruoan tarjoilun ei tarvitse välttämättä tapahtua valmistuspäivänä. Tähän perustuu myös Cook and chill -tuotantotapa. Tutkimusyhteistyötä tehtiin Pirkkalan tuotanto...

  12. Modelling seasonal effects of temperature and precipitation on honey bee winter mortality in a temperate climate.

    Science.gov (United States)

    Switanek, Matthew; Crailsheim, Karl; Truhetz, Heimo; Brodschneider, Robert

    2017-02-01

    Insect pollinators are essential to global food production. For this reason, it is alarming that honey bee (Apis mellifera) populations across the world have recently seen increased rates of mortality. These changes in colony mortality are often ascribed to one or more factors including parasites, diseases, pesticides, nutrition, habitat dynamics, weather and/or climate. However, the effect of climate on colony mortality has never been demonstrated. Therefore, in this study, we focus on longer-term weather conditions and/or climate's influence on honey bee winter mortality rates across Austria. Statistical correlations between monthly climate variables and winter mortality rates were investigated. Our results indicate that warmer and drier weather conditions in the preceding year were accompanied by increased winter mortality. We subsequently built a statistical model to predict colony mortality using temperature and precipitation data as predictors. Our model reduces the mean absolute error between predicted and observed colony mortalities by 9% and is statistically significant at the 99.9% confidence level. This is the first study to show clear evidence of a link between climate variability and honey bee winter mortality. Copyright © 2016 British Geological Survey, NERC. Published by Elsevier B.V. All rights reserved.

  13. Cook & Chill - Rapid Chilling of Food 'in situ'

    DEFF Research Database (Denmark)

    Paul, Joachim

    2003-01-01

    for a given product and process and to compare different cooling fluids and methods. Chilling of hot products in professional cooking kettles immediately after cooking is achieved best by using Binary Ice. The paper gives an equation, which describes the cooling velocity for such kettles and other products...

  14. New airborne pathogen transport model for upper-room UVGI spaces conditioned by chilled ceiling and mixed displacement ventilation: Enhancing air quality and energy performance

    International Nuclear Information System (INIS)

    Kanaan, Mohamad; Ghaddar, Nesreen; Ghali, Kamel; Araj, Georges

    2014-01-01

    Highlights: • A model of bacteria transport is developed in CC/DV conditioned spaces with UVGI. • The model identifies buoyant, partially mixed, and fully mixed transport zones. • The predicted bacteria concentration agreed well with CFD results. • The higher the supply flow rate, the more restrictive is return air mixing ratio. • Upper-room UVGI results in higher return mixing and 33% in energy savings. - Abstract: The maximum allowable return air ratio in chilled ceiling (CC) and mixed displacement ventilation (DV) system for good air quality is regulated by acceptable levels of CO 2 concentration not to exceed 700 ppm and airborne bacterial count to satisfy World Health Organization (WHO) requirement for bacterial count not to exceed 500 CFU/m 3 . Since the CC/DV system relies on buoyancy effects for driving the contaminated air upwards, infectious particles will recirculate in the upper zone allowing effective utilization of upper-room ultraviolet germicidal irradiation (UVGI) to clean return air. The aim of this work is to develop a new airborne bacteria transport plume-multi-layer zonal model at low computational cost to predict bacteria concentration distribution in mixed CC/DV conditioned room without and with upper-room UVGI installed. The results of the simplified model were compared with layer-averaged concentration predictions of a detailed and experimentally-validated 3-D computational fluid dynamics (CFD) model. The comparison showed good agreement between bacteria transport model results and CFD predictions of room air bacteria concentration with maximum error of ±10.4 CFU/m 3 in exhaust air. The simplified model captured the vertical bacteria concentration distribution in room air as well as the locking effect of highest concentration happening at the stratification level. The developed bacteria transport model was used in a case study to determine the return air mixing ratio that minimizes energy consumption and maintains acceptable IAQ

  15. Modelling the winter distribution of a rare and endangered migrant, the Aquatic Warbler Acrocephalus paludicola

    DEFF Research Database (Denmark)

    Walther, Bruno A; Schäffer, Norbert; van Niekerk, Adriaan

    2007-01-01

    . Such model predictions may be useful guidelines to focus further field research on the Aquatic Warbler. Given the excellent model predictions in this study, this novel technique may prove useful to model the distribution of other rare and endangered species, thus providing a means to guide future survey......The Aquatic Warbler Acrocephalus paludicola is one of the most threatened Western Palearctic passerine species, classified as globally Vulnerable. With its breeding grounds relatively secure, a clear need remains for the monitoring and protection of the migration and wintering grounds of this rare...... and endangered migrant. Recent research has shown that the Aquatic Warbler migrates through northwest Africa in autumn and spring. The wintering grounds are apparently limited to wetlands of sub-Saharan West Africa, with records from only about 20 localities in Mauritania, Mali, Senegal and Ghana. Given the lack...

  16. Modeling influences on winter distribution of caribou in northwestern Alaska through use of satellite telemetry

    Directory of Open Access Journals (Sweden)

    Kyle Joly

    2011-09-01

    Full Text Available I hypothesize that the distribution of barren-ground caribou (Rangifer tarandus granti is affected by multiple, interrelated factors. These factors include, but are not limited to, terrain and snow characteristics as well as predation pressure and habitat. To test this hypothesis, I attributed caribou locations derived from satellite telemetry over a 6 year period with terrain (elevation, slope, aspect, and ruggedness, habitat characteristics, and moose density - potentially an index of wolf predation pressure. These locations were compared to random locations, attributed using the same data layers, using logistic regression techniques to develop resource selection functions (RSFs. I found that caribou moved significantly less during mid-winter than early- or late-winter and that cows moved significantly more in April than bulls due to their earlier departure on their spring migration. Distribution was different between cows and bulls. Terrain variables were important factors but were scale-dependent. Cows avoided forested areas, highlighting the importance of tundra habitats, and selected for dwarf shrub, with relatively high lichen cover, and sedge habitat types. Bulls selected for dryas, coniferous forest and dwarf shrub habitats but against lowland sedge, upland shrub and burned tundra. Cow distribution was negatively correlated with moose density at the scale of the Seward Peninsula. My results support the hypothesis that caribou distribution during winter in northwest Alaska is affected by multiple, interrelated factors. These results may be useful for researchers to track and/or model changes in future patterns of range use over winter.

  17. Exceptional winter storms affecting Western Iberia and extremes: diagnosis, modelling and multi-model ensemble projection

    Science.gov (United States)

    Liberato, M. L. R.; Pinto, J. G.; Gil, V.; Ramos, A. M.; Trigo, R. M.

    2017-12-01

    Extratropical cyclones dominate autumn and winter weather over Western Europe and particularly over the Iberian Peninsula. Intense, high-impact storms are one of the major weather risks in the region, mostly due to the simultaneous occurrence of high winds and extreme precipitation events. These intense extratropical cyclones may result in windstorm damage, flooding and coastal storm surges, with large societal impacts. In Portugal, due to the extensive human use of coastal areas, the natural and built coastal environments have been amongst the most affected. In this work several historical winter storms that adversely affected the Western Iberian Peninsula are studied in detail in order to contribute to an improved assessment of the characteristics of these events. The diagnosis has been performed based on instrumental daily precipitation and wind records, on satellite images, on reanalysis data and through model simulations. For several examples the synoptic evolution and upper-level dynamics analysis of physical processes controlling the life cycle of extratropical storms associated with the triggering of the considered extreme events has also been accomplished. Furthermore, the space-time variability of the exceptionally severe storms affecting Western Iberia over the last century and under three climate scenarios (the historical simulation, the RCP4.5 and RCP8.5 scenarios) is presented. These studies contribute to improving the knowledge of atmospheric dynamics controlling the life cycle of midlatitude storms associated to severe weather (precipitation and wind) in the Iberian Peninsula. AcknowledgementsThis work is supported by the Portuguese Foundation for Science and Technology (FCT), Portugal, through project UID/GEO/50019/2013 - Instituto Dom Luiz. A. M. Ramos is also supported by a FCT postdoctoral grant (FCT/DFRH/SFRH/BPD/84328/2012).

  18. Winter weather demand considerations.

    Science.gov (United States)

    2015-04-01

    Winter weather has varied effects on travel behavior. Using 418 survey responses from the Northern Virginia : commuting area of Washington, D.C. and binary logit models, this study examines travel related changes under : different types of winter wea...

  19. Chilled storage of foods - principles

    Science.gov (United States)

    Chilled storage is the most common method for preserving perishable foods. The consumers’ increasing demand for convenient, minimally processed foods has caused food manufacturers to increase production of refrigerated foods worldwide. This book chapter reviews the development of using low tempera...

  20. Modeling organic aerosol concentrations and properties during winter 2014 in the northwestern Mediterranean region

    OpenAIRE

    Chrit, Mounir; Sartelet, Karine; Sciare, Jean; Majdi, Marwa; Nicolas, José; Petit, Jean-Eudes; Dulac, François

    2018-01-01

    Organic aerosols are measured at a remote site (Ersa) on Corsica Cape in the northwestern Mediterranean basin during the Chemistry-Aerosol Mediterranean Experiment (CharMEx) winter campaign of 2014, when high organic concentrations from anthropogenic origin are observed. This work aims at representing the observed organic aerosol concentrations and properties (oxidation state) using the air-quality model Polyphemus with a surrogate approach for secondary organic aerosol (SOA) formation. Becau...

  1. [Adaptability of APSIM model in Southwestern China: A case study of winter wheat in Chongqing City].

    Science.gov (United States)

    Dai, Tong; Wang, Jing; He, Di; Zhang, Jian-ping; Wang, Na

    2015-04-01

    Field experimental data of winter wheat and parallel daily meteorological data at four typical stations in Chongqing City were used to calibrate and validate APSIM-wheat model and determine the genetic parameters for 12 varieties of winter wheat. The results showed that there was a good agreement between the simulated and observed growth periods from sowing to emergence, flowering and maturity of wheat. Root mean squared errors (RMSEs) between simulated and observed emergence, flowering and maturity were 0-3, 1-8, and 0-8 d, respectively. Normalized root mean squared errors (NRMSEs) between simulated and observed above-ground biomass for 12 study varieties were less than 30%. NRMSE between simulated and observed yields for 10 varieties out of 12 study varieties were less than 30%. APSIM-wheat model performed well in simulating phenology, aboveground biomass and yield of winter wheat in Chongqing City, which could provide a foundational support for assessing the impact of climate change on wheat production in the study area based on the model.

  2. Design and Modelling of Water Chilling Production System by the Combined Effects of Evaporation and Night Sky Radiation

    Directory of Open Access Journals (Sweden)

    Ahmed Y. Taha Al-Zubaydi

    2014-01-01

    Full Text Available The design and mathematical modelling of thermal radiator panel to be used primarily to measure night sky radiation wet coated surface is presented in this paper. The panel consists of an upper dry surface coated aluminium sheet laminated to an ethylene vinyl acetate foam backing block as an insulation. Water is sprayed onto the surface of the panel so that an evaporative cooling effect is gained in addition to the radiation effect; the surface of a panel then is wetted in order to study and measure the night sky radiation from the panel wet surface. In this case, the measuring water is circulated over the upper face of this panel during night time. Initial TRNSYS simulations for the performance of the system are presented and it is planned to use the panel as calibrated instruments for discriminating between the cooling effects of night sky radiation and evaporation.

  3. Climate model assessment of changes in winter-spring streamflow timing over North America

    Science.gov (United States)

    Kam, Jonghun; Knutson, Thomas R.; Milly, Paul C. D.

    2018-01-01

    Over regions where snow-melt runoff substantially contributes to winter-spring streamflows, warming can accelerate snow melt and reduce dry-season streamflows. However, conclusive detection of changes and attribution to anthropogenic forcing is hindered by brevity of observational records, model uncertainty, and uncertainty concerning internal variability. In this study, a detection/attribution of changes in mid-latitude North American winter-spring streamflow timing is examined using nine global climate models under multiple forcing scenarios. In this study, robustness across models, start/end dates for trends, and assumptions about internal variability is evaluated. Marginal evidence for an emerging detectable anthropogenic influence (according to four or five of nine models) is found in the north-central U.S., where winter-spring streamflows have been coming earlier. Weaker indications of detectable anthropogenic influence (three of nine models) are found in the mountainous western U.S./southwestern Canada and in extreme northeastern U.S./Canadian Maritimes. In the former region, a recent shift toward later streamflows has rendered the full-record trend toward earlier streamflows only marginally significant, with possible implications for previously published climate change detection findings for streamflow timing in this region. In the latter region, no forced model shows as large a shift toward earlier streamflow timing as the detectable observed shift. In other (including warm, snow-free) regions, observed trends are typically not detectable, although in the U.S. central plains we find detectable delays in streamflow, which are inconsistent with forced model experiments.

  4. Influence of the ventilation system on thermal comfort of the chilled panel system in heating mode

    Energy Technology Data Exchange (ETDEWEB)

    Tian, Zhe; Ding, Yan; Wang, Shuo; Yin, Xinglei; Wang, Menglei [Tianjin University, Tianjin 300072 (China)

    2010-12-15

    In heating mode, fresh air is still essential for a chilled panel system in order to ensure the indoor air quality. In this paper, a chilled ceiling panel system was designed and built in a typical office room. The thermal environment and thermal comfort in the room were fully measured and evaluated by using the Fanger's PMV-PPD model and the standard of ISO 7730 respectively, when room was heated in two modes, one of which is the chilled panel heating mode and the other of which is the combined heating mode of chilled panel and supply air. The research results indicate that in the combined mode, ceiling ventilation improves the general thermal comfort and reduces the risk of local discomfort. Under the condition of same general thermal comfort, the heating supply upper limit of chilled panel can be increased by 12.3% because of air mixing effect caused by introduction of air ventilation. (author)

  5. Application of regional climate models to the Indian winter monsoon over the western Himalayas.

    Science.gov (United States)

    Dimri, A P; Yasunari, T; Wiltshire, A; Kumar, P; Mathison, C; Ridley, J; Jacob, D

    2013-12-01

    The Himalayan region is characterized by pronounced topographic heterogeneity and land use variability from west to east, with a large variation in regional climate patterns. Over the western part of the region, almost one-third of the annual precipitation is received in winter during cyclonic storms embedded in westerlies, known locally as the western disturbance. In the present paper, the regional winter climate over the western Himalayas is analyzed from simulations produced by two regional climate models (RCMs) forced with large-scale fields from ERA-Interim. The analysis was conducted by the composition of contrasting (wet and dry) winter precipitation years. The findings showed that RCMs could simulate the regional climate of the western Himalayas and represent the atmospheric circulation during extreme precipitation years in accordance with observations. The results suggest the important role of topography in moisture fluxes, transport and vertical flows. Dynamical downscaling with RCMs represented regional climates at the mountain or even event scale. However, uncertainties of precipitation scale and liquid-solid precipitation ratios within RCMs are still large for the purposes of hydrological and glaciological studies. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Modelling soil water content variations under drought stress on soil column cropped with winter wheat

    Directory of Open Access Journals (Sweden)

    Csorba Szilveszter

    2014-12-01

    Full Text Available Mathematical models are effective tools for evaluating the impact of predicted climate change on agricultural production, but it is difficult to test their applicability to future weather conditions. We applied the SWAP model to assess its applicability to climate conditions, differing from those, for which the model was developed. We used a database obtained from a winter wheat drought stress experiment. Winter wheat was grown in six soil columns, three having optimal water supply (NS, while three were kept under drought-stressed conditions (S. The SWAP model was successfully calibrated against measured values of potential evapotranspiration (PET, potential evaporation (PE and total amount of water (TSW in the soil columns. The Nash-Sutcliffe model efficiency coefficient (N-S for TWS for the stressed columns was 0.92. For the NS treatment, we applied temporally variable soil hydraulic properties because of soil consolidation caused by regular irrigation. This approach improved the N-S values for the wetting-drying cycle from -1.77 to 0.54. We concluded that the model could be used for assessing the effects of climate change on soil water regime. Our results indicate that soil water balance studies should put more focus on the time variability of structuredependent soil properties.

  7. Wintering habitat model for the North Atlantic Right Whale (Eubalaena glacialis) in the southeastern United States.

    Science.gov (United States)

    Gowan, Timothy A; Ortega-Ortiz, Joel G

    2014-01-01

    The coastal waters off the southeastern United States (SEUS) are a primary wintering ground for the endangered North Atlantic right whale (Eubalaena glacialis), used by calving females along with other adult and juvenile whales. Management actions implemented in this area for the recovery of the right whale population rely on accurate habitat characterization and the ability to predict whale distribution over time. We developed a temporally dynamic habitat model to predict wintering right whale distribution in the SEUS using a generalized additive model framework and aerial survey data from 2003/2004 through 2012/2013. We built upon previous habitat models for right whales in the SEUS and include data from new aerial surveys that extend the spatial coverage of the analysis, particularly in the northern portion of this wintering ground. We summarized whale sightings, survey effort corrected for probability of whale detection, and environmental data at a semimonthly resolution. Consistent with previous studies, sea surface temperature (SST), water depth, and survey year were significant predictors of right whale relative abundance. Additionally, distance to shore, distance to the 22°C SST isotherm, and an interaction between time of year and latitude (to account for the latitudinal migration of whales) were also selected in the analysis presented here. Predictions from the model revealed that the location of preferred habitat differs within and between years in correspondence with variation in environmental conditions. Although cow-calf pairs were rarely sighted in the company of other whales, there was minimal evidence that the preferred habitat of cow-calf pairs was different than that of whale groups without calves at the scale of this study. The results of this updated habitat model can be used to inform management decisions for a migratory species in a dynamic oceanic environment.

  8. Validation of a limited area model over Dome C, Antarctic Plateau, during winter

    Energy Technology Data Exchange (ETDEWEB)

    Gallee, Hubert; Gorodetskaya, Irina V. [Laboratoire de Glaciologie et de Geophysique de l' Environnement, CNRS, 54, rue Moliere, BP. 96, St Martin d' Heres Cedex (France)

    2010-01-15

    The limited area model MAR (Modele Atmospherique Regional) is validated over the Antarctic Plateau for the period 2004-2006, focussing on Dome C during the cold season. MAR simulations are made by initializing the model once and by forcing it through its lateral and top boundaries by the ECMWF operational analyses. Model outputs compare favourably with observations from automatic weather station (AWS), radiometers and atmospheric soundings. MAR is able to simulate the succession of cold and warm events which occur at Dome C during winter. Larger longwave downwelling fluxes (LWD) are responsible for higher surface air temperatures and weaker surface inversions during winter. Warm events are better simulated when the small Antarctic precipitating snow particles are taken into account in radiative transfer computations. MAR stratosphere cools during the cold season, with the coldest temperatures occurring in conjunction with warm events at the surface. The decrease of saturation specific humidity associated with these coldest temperatures is responsible for the formation of polar stratospheric clouds (PSCs) especially in August-September. PSCs then contribute to the surface warming by increasing the surface downwelling longwave flux. (orig.)

  9. A model for making field-based nitrogen recommendations for winter wheat in western oregon

    International Nuclear Information System (INIS)

    Baloch, D.M.; Malghani, M.A.K.; Khan, M.A.; Kakar, E.

    2010-01-01

    A model based on early spring soil and tissue analysis was developed and evaluated for predicting the need for additional nitrogen (N) fertilizer on winter wheat. To develop the model, On-farm trials were' established over three years 1994-95 in grower's fields at three different locations across the Willamette Valley of western Oregon. Two field-scale validation trials were run in 1996-97. Rotations were soft white winter wheat following grass seed, sweet corn or a legume. Four treatments, including a check receiving no nitrogen, were used at each site At the site where wheat followed corn, the predicted optimum N rate was 168 kg N ha/sup -1/ however, the 112 kg N ha/sup -1/ rate was the optimum rate predicted by the developed model. The 84 kgN ha/sup -1/ and 140 kgN ha/sup -1/ rates were selected to bracket the recommended rate (+- 28 kg N ha/sup -1/). Wheat following grass seed had high soil supplied N which depressed the yield even at moderate fertilizer N rates. The model overall accurately assess field-specific optimum fertilizer N status. (author)

  10. Targeting and design of chilled water network

    International Nuclear Information System (INIS)

    Foo, Dominic C.Y.; Ng, Denny K.S.; Leong, Malwynn K.Y.; Chew, Irene M.L.; Subramaniam, Mahendran; Aziz, Ramlan; Lee, Jui-Yuan

    2014-01-01

    Highlights: • Minimum flowrate targeting for chilled water network. • Mixed series/parallel configuration of chilled water-using units. • Integrated cooling and chilled water networks. - Abstract: Chilled water is a common cooling agent used in various industrial, commercial and institutional facilities. In conventional practice, chilled water is distributed via chilled water networks (CHWNs) in parallel configuration to provide required air conditioning and/or equipment cooling in the heating, ventilating and air conditioning (HVAC) system. In this paper, process integration approach based on pinch analysis technique is used to address energy efficiency issues in the CHWN system for grassroots design problem. Graphical and algebraic targeting techniques are developed to identify the minimum chilled water flowrate needed to remove a given amount of heat load from the CHWN. Doing this leads to higher chilled water return temperature and enhanced energy efficiency of the HVAC system. A recent proposed network design technique is extended to synthesize the CHWN in a mixed series/parallel configuration. A novel concept of integrated cooling and chilled water networks (IWN) is also proposed in this work, with its targeting and design techniques presented. Hypothetical examples and an industrial case study are solved to elucidate the proposed approaches

  11. Individually controlled localized chilled beam in conjunction with chilled ceiling: Part 2 – Human response

    DEFF Research Database (Denmark)

    Arghand, Taha; Pastuszka, Zuzanna; Bolashikov, Zhecho Dimitrov

    2016-01-01

    The response of 24 subjects to the local environment established by localized chilled beam combined with chilled ceiling (LCBCC) was studied and compared with response to the environment generated by mixing ventilation combined with chilled ceiling (CCMV) at two temperature conditions of 26°C and...

  12. Individually controlled localized chilled beam in conjunction with chilled ceiling: Part 1 – Physical environment

    DEFF Research Database (Denmark)

    Arghand, Taha; Bolashikov, Zhecho Dimitrov; Kosonen, Risto

    2016-01-01

    This study investigates the indoor environment generated by localized chilled beam coupled with chilled ceiling (LCBCC) and compares it with the environment generated by mixing ventilation coupled with chilled ceiling (CCMV). The experiments were performed in a mock-up of single office (4.1 m × 4...

  13. Evaluation of a model for predicting Avena fatua and Descurainia sophia seed emergence in winter rapeseed

    Energy Technology Data Exchange (ETDEWEB)

    Aboutalebian, M.A.; Nazari, S.; Gonzalez-Andujar, J.L.

    2017-07-01

    Avena fatua and Descurainia sophia are two important annual weeds throughout winter rapeseed (Brassica napus L.) production systems in the semiarid region of Iran. Timely and more accurate control of both species may be developed if there is a better understanding of its emergence patterns. Non-linear regression techniques are usually unable to accurately predict field emergence under such environmental conditions. The objectives of this research were to evaluate the emergence patterns of A. fatua and D. sophia and determine if emergence could be predicted using cumulative soil thermal time in degree days (CTT). In the present work, cumulative seedling emergence from a winter rapeseed field during 3 years data set was fitted to cumulative soil CTT using Weibull and Gompertz functions. The Weibull model provided a better fit, based on coefficient of determination (R2sqr), root mean square of error (RMSE) and Akaike index (AICd), compared to the Gompertz model between 2013 and 2016 seasons for both species. Maximum emergence of A. fatua occured 70-119 days after sowing or after equals 329-426 °Cd, while in D. sophia it occurred 119-134 days after sowing rapeseed equals 373-470 °Cd. Both models can aid in the future study of A. fatua and D. sophia emergence and assist growers and agricultural professionals with planning timely and more accurate A. fatua and D. sophia control.

  14. Forecasting of primary energy consumption data in the United States: A comparison between ARIMA and Holter-Winters models

    Science.gov (United States)

    Rahman, A.; Ahmar, A. S.

    2017-09-01

    This research has a purpose to compare ARIMA Model and Holt-Winters Model based on MAE, RSS, MSE, and RMS criteria in predicting Primary Energy Consumption Total data in the US. The data from this research ranges from January 1973 to December 2016. This data will be processed by using R Software. Based on the results of data analysis that has been done, it is found that the model of Holt-Winters Additive type (MSE: 258350.1) is the most appropriate model in predicting Primary Energy Consumption Total data in the US. This model is more appropriate when compared with Holt-Winters Multiplicative type (MSE: 262260,4) and ARIMA Seasonal model (MSE: 723502,2).

  15. Modeling Root Growth, Crop Growth and N Uptake of Winter Wheat Based on SWMS_2D: Model and Validation

    Directory of Open Access Journals (Sweden)

    Dejun Yang

    Full Text Available ABSTRACT Simulations for root growth, crop growth, and N uptake in agro-hydrological models are of significant concern to researchers. SWMS_2D is one of the most widely used physical hydrologically related models. This model solves equations that govern soil-water movement by the finite element method, and has a public access source code. Incorporating key agricultural components into the SWMS_2D model is of practical importance, especially for modeling some critical cereal crops such as winter wheat. We added root growth, crop growth, and N uptake modules into SWMS_2D. The root growth model had two sub-models, one for root penetration and the other for root length distribution. The crop growth model used was adapted from EU-ROTATE_N, linked to the N uptake model. Soil-water limitation, nitrogen limitation, and temperature effects were all considered in dry-weight modeling. Field experiments for winter wheat in Bouwing, the Netherlands, in 1983-1984 were selected for validation. Good agreements were achieved between simulations and measurements, including soil water content at different depths, normalized root length distribution, dry weight and nitrogen uptake. This indicated that the proposed new modules used in the SWMS_2D model are robust and reliable. In the future, more rigorous validation should be carried out, ideally under 2D situations, and attention should be paid to improve some modules, including the module simulating soil N mineralization.

  16. Numerical Modeling of Persistent Winter Fog over the Indo-Gangetic Plains

    Science.gov (United States)

    Ghimire, S.; Adhikary, B.; Praveen, P. S.; Panday, A. K.

    2017-12-01

    Every winter the Indo-Gangetic Plains (IGP) in northern South Asia; bounded by the great Himalayas in the north, are periodically covered by dense and persistent fog that severely impacts day-to-day activities of several hundred million people. The fog can stretch over several hundred kilometers and last several days in many locations. Despite the fog's high impact, there are very limited in-situ observations available to characterize persistent fog episodes. Also, there has been very little success to date in accurately predicting the fog occurrence and extent over a larger area such as IGP. This study will present insights into the performance of the Weather Research and Forecasting (WRF) model simulating persistent winter fog prediction in the IGP region, compared to satellite observations and in-situ measurements. Since fog is not a prognostic variable in WRF, the study presents results based on multi-rule diagnostic algorithms published in peer reviewed journals. In addition, fog episodes were analyzed using the Air Force Weather Agency (AFWA) diagnostics package available for WRF. On a regional scale, MODIS data onboard the TERRA and AQUA satellites are used to evaluate model performance skills. At a local scale, the model is evaluated at two sites in the southern Nepal, Lumbini and Chitwan, located in the IGP. Lumbini and Chitwan observatories have Luftt and Biral weather sensors which allow monitoring presence of fog, visibility range and surface meteorology. In addition, for Chitwan, data from DMT Fog Monitor (FM 120) and Luftt CHM 15K Ceilometer were used to compare model performance for liquid-water content and planetary boundary layer during foggy and non-foggy days.

  17. Diagnosis and Modeling of the Explosive Development of Winter Storms: Sensitivity to PBL Schemes

    Science.gov (United States)

    Liberato, Margarida L. R.; Pradhan, Prabodha K.

    2014-05-01

    The correct representation of extreme windstorms in regional models is of great importance for impact studies of climate change. The Iberian Peninsula has recently witnessed major damage from winter extratropical intense cyclones like Klaus (January 2009), Xynthia (February 2010) and Gong (January 2013) which formed over the mid-Atlantic, experienced explosive intensification while travelling eastwards at lower latitudes than usual [Liberato et al. 2011; 2013]. In this paper the explosive development of these storms is simulated by the advanced mesoscale Weather Research and Forecasting Model (WRF v 3.4.1), initialized with NCEP Final Analysis (FNL) data as initial and lateral boundary conditions (boundary conditions updated in every 3 hours intervals). The simulation experiments are conducted with two domains, a coarser (25km) and nested (8.333km), covering the entire North Atlantic and Iberian Peninsula region. The characteristics of these storms (e.g. wind speed, precipitation) are studied from WRF model and compared with multiple observations. In this context simulations with different Planetary Boundary Layer (PBL) schemes are performed. This approach aims at understanding which mechanisms favor the explosive intensification of these storms at a lower than usual latitudes, thus improving the knowledge of atmospheric dynamics (including small-scale processes) on controlling the life cycle of midlatitude extreme storms and contributing to the improvement in predictability and in our ability to forecast storms' impacts over Iberian Peninsula. Acknowledgments: This work was partially supported by FEDER (Fundo Europeu de Desenvolvimento Regional) funds through the COMPETE (Programa Operacional Factores de Competitividade) and by national funds through FCT (Fundação para a Ciência e a Tecnologia, Portugal) under project STORMEx FCOMP-01-0124-FEDER- 019524 (PTDC/AAC-CLI/121339/2010). References: Liberato M.L.R., J.G. Pinto, I.F. Trigo, R.M. Trigo (2011) Klaus - an

  18. Development of groundwater pesticide exposure modeling scenarios for vulnerable spring and winter wheat-growing areas.

    Science.gov (United States)

    Padilla, Lauren; Winchell, Michael; Peranginangin, Natalia; Grant, Shanique

    2017-11-01

    Wheat crops and the major wheat-growing regions of the United States are not included in the 6 crop- and region-specific scenarios developed by the US Environmental Protection Agency (USEPA) for exposure modeling with the Pesticide Root Zone Model conceptualized for groundwater (PRZM-GW). The present work augments the current scenarios by defining appropriately vulnerable PRZM-GW scenarios for high-producing spring and winter wheat-growing regions that are appropriate for use in refined pesticide exposure assessments. Initial screening-level modeling was conducted for all wheat areas across the conterminous United States as defined by multiple years of the Cropland Data Layer land-use data set. Soil, weather, groundwater temperature, evaporation depth, and crop growth and management practices were characterized for each wheat area from publicly and nationally available data sets and converted to input parameters for PRZM. Approximately 150 000 unique combinations of weather, soil, and input parameters were simulated with PRZM for an herbicide applied for postemergence weed control in wheat. The resulting postbreakthrough average herbicide concentrations in a theoretical shallow aquifer were ranked to identify states with the largest regions of relatively vulnerable wheat areas. For these states, input parameters resulting in near 90 th percentile postbreakthrough average concentrations corresponding to significant wheat areas with shallow depth to groundwater formed the basis for 4 new spring wheat scenarios and 4 new winter wheat scenarios to be used in PRZM-GW simulations. Spring wheat scenarios were identified in North Dakota, Montana, Washington, and Texas. Winter wheat scenarios were identified in Oklahoma, Texas, Kansas, and Colorado. Compared to the USEPA's original 6 scenarios, postbreakthrough average herbicide concentrations in the new scenarios were lower than all but Florida Potato and Georgia Coastal Peanuts of the original scenarios and better

  19. Chills

    Science.gov (United States)

    ... the child to be uncomfortable, give pain-relieving tablets or liquid. Non-aspirin pain-relievers such as ... fever. In: Hall JE, ed. Guyton and Hall Textbook of Medical Physiology . 13th ed. Philadelphia, PA: Elsevier; ...

  20. Forecasting and Analysis of Monthly Rainfalls in Ardabil Province by Arima, Autoregrressive, and Winters Models

    Directory of Open Access Journals (Sweden)

    B. Salahi

    2017-01-01

    Full Text Available Introduction: Rainfall has the highest variability at time and place scale. Rainfall fluctuation in different geographical areas reveals the necessity of investigating this climate element and suitable models to forecast the rate of precipitation for regional planning. Ardabil province has always faced rainfall fluctuations and shortage of water supply. Precipitation is one of the most important features of the environment. The amount of precipitation over time and in different places is subject to large fluctuations which may be periodical. Studies show that, due to the certain complexities of rainfall, the models which used to predict future values will also need greater accuracy and less error. Among the forecasting models, Arima has more applications and it has replaced with other models. Materials and Methods: In this research, through order 2 Autoregrressive, Winters, and Arima models, monthly rainfalls of Ardabil synoptic station (representing Ardabil province for a 31-year period (1977-2007 were investigated. To assess the presence or absence of significant changes in mean precipitation of Ardabil synoptic station, rainfall of this station was divided into two periods: 1977-1993 and 1994-2010. T-test was used to statistically examine the difference between the two periods. After adjusting the data, descriptive statistics were applied. In order to model the total monthly precipitation of Ardabil synoptic station, Winters, Autoregressive, and Arima models were used. Among different models, the best options were chosen to predict the time series including the mean absolute deviation (MAD, the mean squared errors (MSE, root mean square errors (RMSE and mean absolute percentage errors (MAPE. In order to select the best model among the available options under investigation, the predicted value of the deviation of the actual value was utilized for the months of 2006-2010. Results and Discussion: Statistical characteristics of the total monthly

  1. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    OpenAIRE

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2014-01-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality a...

  2. The influence of boreal spring Arctic Oscillation on the subsequent winter ENSO in CMIP5 models

    Science.gov (United States)

    Chen, Shangfeng; Chen, Wen; Yu, Bin

    2017-05-01

    This study examines the influence of boreal spring Arctic Oscillation (AO) on the subsequent winter El Niño-Southern Oscillation (ENSO) using 15 climate model outputs from the Coupled Model Intercomparison Project Phase 5 (CMIP5). Results show that, out of the 15 CMIP5 models, CCSM4 and CNRM-CM5 can well reproduce the significant AO-ENSO connection. These two models capture the observed spring AO related anomalous cyclone (anticyclone) over the subtropical western-central North Pacific, and westerly (easterly) winds over the tropical western-central Pacific. In contrast, the spring AO-related anomalous circulation over the subtropical North Pacific is insignificant in the other 13 models, and the simulations in these models cannot capture the significant influence of the spring AO on ENSO. Further analyses indicate that the performance of the CMIP5 simulations in reproducing the AO-ENSO connection is related to the ability in simulating the spring North Pacific synoptic eddy intensity and the spring AO's Pacific component. Strong synoptic-scale eddy intensity results in a strong synoptic eddy feedback on the mean flow, leading to strong cyclonic circulation anomalies over the subtropical North Pacific, which contributes to a significant AO-ENSO connection. In addition, a strong spring AO's Pacific component and associated easterly wind anomalies to its south may provide more favorable conditions for the development of spring AO-related cyclonic circulation anomalies over the subtropical North Pacific.

  3. A Winter Distribution Model for Bicknell’s Thrush (Catharus bicknelli), a Conservation Tool for a Threatened Migratory Songbird

    Science.gov (United States)

    McFarland, Kent P.; Rimmer, Christopher C.; Goetz, James E.; Aubry, Yves; Wunderle, Joseph M.; Sutton, Anne; Townsend, Jason M.; Sosa, Alejandro Llanes; Kirkconnell, Arturo

    2013-01-01

    Conservation planning and implementation require identifying pertinent habitats and locations where protection and management may improve viability of targeted species. The winter range of Bicknell’s Thrush (Catharus bicknelli), a threatened Nearctic-Neotropical migratory songbird, is restricted to the Greater Antilles. We analyzed winter records from the mid-1970s to 2009 to quantitatively evaluate winter distribution and habitat selection. Additionally, we conducted targeted surveys in Jamaica (n = 433), Cuba (n = 363), Dominican Republic (n = 1,000), Haiti (n = 131) and Puerto Rico (n = 242) yielding 179 sites with thrush presence. We modeled Bicknell’s Thrush winter habitat selection and distribution in the Greater Antilles in Maxent version 3.3.1. using environmental predictors represented in 30 arc second study area rasters. These included nine landform, land cover and climatic variables that were thought a priori to have potentially high predictive power. We used the average training gain from ten model runs to select the best subset of predictors. Total winter precipitation, aspect and land cover, particularly broadleaf forests, emerged as important variables. A five-variable model that contained land cover, winter precipitation, aspect, slope, and elevation was the most parsimonious and not significantly different than the models with more variables. We used the best fitting model to depict potential winter habitat. Using the 10 percentile threshold (>0.25), we estimated winter habitat to cover 33,170 km2, nearly 10% of the study area. The Dominican Republic contained half of all potential habitat (51%), followed by Cuba (15.1%), Jamaica (13.5%), Haiti (10.6%), and Puerto Rico (9.9%). Nearly one-third of the range was found to be in protected areas. By providing the first detailed predictive map of Bicknell’s Thrush winter distribution, our study provides a useful tool to prioritize and direct conservation planning for this and

  4. Route prediction model of infectious diseases for 2018 Winter Olympics in Korea

    International Nuclear Information System (INIS)

    Kim, Eungyeong; Lee, Seok; Byun, Young Tae; Kim, Jae Hun; Lee, Taikjin; Lee, Hyuk-jae

    2014-01-01

    There are many types of respiratory infectious diseases caused by germs, virus, mycetes and parasites. Researchers recently have tried to develop mathematical models to predict the epidemic of infectious diseases. However, with the development of ground transportation system in modern society, the spread of infectious diseases became faster and more complicated in terms of the speed and the pathways. The route of infectious diseases during Vancouver Olympics was predicted based on the Susceptible-Infectious-Recovered (SIR) model. In this model only the air traffic as an essential factor for the intercity migration of infectious diseases was involved. Here, we propose a multi-city transmission model to predict the infection route during 2018 Winter Olympics in Korea based on the pre-existing SIR model. Various types of transportation system such as a train, a car, a bus, and an airplane for the interpersonal contact in both inter- and intra-city are considered. Simulation is performed with assumptions and scenarios based on realistic factors including demographic, transportation and diseases data in Korea. Finally, we analyze an economic profit and loss caused by the variation of the number of tourists during the Olympics

  5. Route prediction model of infectious diseases for 2018 Winter Olympics in Korea

    Science.gov (United States)

    Kim, Eungyeong; Lee, Seok; Byun, Young Tae; Kim, Jae Hun; Lee, Hyuk-jae; Lee, Taikjin

    2014-03-01

    There are many types of respiratory infectious diseases caused by germs, virus, mycetes and parasites. Researchers recently have tried to develop mathematical models to predict the epidemic of infectious diseases. However, with the development of ground transportation system in modern society, the spread of infectious diseases became faster and more complicated in terms of the speed and the pathways. The route of infectious diseases during Vancouver Olympics was predicted based on the Susceptible-Infectious-Recovered (SIR) model. In this model only the air traffic as an essential factor for the intercity migration of infectious diseases was involved. Here, we propose a multi-city transmission model to predict the infection route during 2018 Winter Olympics in Korea based on the pre-existing SIR model. Various types of transportation system such as a train, a car, a bus, and an airplane for the interpersonal contact in both inter- and intra-city are considered. Simulation is performed with assumptions and scenarios based on realistic factors including demographic, transportation and diseases data in Korea. Finally, we analyze an economic profit and loss caused by the variation of the number of tourists during the Olympics.

  6. Modeling large-scale winter recreation terrain selection with implications for recreation management and wildlife

    Science.gov (United States)

    Lucretia E. Olson; John R. Squires; Elizabeth K. Roberts; Aubrey D. Miller; Jacob S. Ivan; Mark Hebblewhite

    2017-01-01

    Winter recreation is a rapidly growing activity, and advances in technology make it possible for increasing numbers of people to access remote backcountry terrain. Increased winter recreation may lead to more frequent conflict between recreationists, as well as greater potential disturbance to wildlife. To better understand the environmental characteristics favored by...

  7. Interannual control of plankton communities by deep winter mixing and prey/predator interactions in the NW Mediterranean: Results from a 30-year 3D modeling study

    Science.gov (United States)

    Auger, P. A.; Ulses, C.; Estournel, C.; Stemmann, L.; Somot, S.; Diaz, F.

    2014-05-01

    A realistic modeling approach is designed to address the role of winter mixing on the interannual variability of plankton dynamics in the north-western (NW) Mediterranean basin. For the first time, a high-resolution coupled hydrodynamic-biogeochemical model (Eco3m-S) covering a 30-year period (1976-2005) is validated on available in situ and satellite data for the NW Mediterranean. In this region, cold, dry winds in winter often lead to deep convection and strong upwelling of nutrients into the euphotic layer. High nutrient contents at the end of winter then support the development of a strong spring bloom of phytoplankton. Model results indicate that annual primary production is not affected by winter mixing due to seasonal balance (minimum in winter and maximum in spring). However, the total annual water column-integrated phytoplankton biomass appears to be favored by winter mixing because zooplankton grazing activity is low in winter and early spring. This reduced grazing is explained here by the rarefaction of prey due to both light limitation and the effect of mixing-induced dilution on prey/predator interactions. A negative impact of winter mixing on winter zooplankton biomass is generally simulated except for mesozooplankton. This difference is assumed to stem from the lower parameterized mortality, top trophic position and detritivorous diet of mesozooplankton in the model. Moreover, model suggests that the variability of annual mesozooplankton biomass is principally modulated by the effects of winter mixing on winter biomass. Thus, interannual variability of winter nutrient contents in the euphotic layer, resulting from winter mixing, would control spring primary production and thus annual mesozooplankton biomass. Our results show a bottom-up control of mesozooplankton communities, as observed at a coastal location of the Ligurian Sea.

  8. Modelling economic losses of historic and present-day high-impact winter storms in Switzerland

    Science.gov (United States)

    Welker, Christoph; Martius, Olivia; Stucki, Peter; Bresch, David; Dierer, Silke; Brönnimann, Stefan

    2015-04-01

    simulate the wind field and related economic impact of both historic and present-day high-impact winter storms in Switzerland since end of the 19th century. Our technique involves the dynamical downscaling of the 20CR to 3 km horizontal resolution using the numerical Weather Research and Forecasting model and the subsequent loss simulation using an open-source impact model. This impact model estimates, for modern economic and social conditions, storm-related economic losses at municipality level, and thus allows a numerical simulation of the impact from both historic and present-day severe winter storms in Switzerland on a relatively fine spatial scale. In this study, we apply the modelling chain to a storm sample of almost 90 high-impact winter storms in Switzerland since 1871, and we are thus able to make a statement of the typical wind and loss patterns of hazardous windstorms in Switzerland. To evaluate our modelling chain, we compare simulated storm losses with insurance loss data for the present-day windstorms "Lothar" and "Joachim" in December 1999 and December 2011, respectively. Our study further includes a range of sensitivity experiments and a discussion of the main sources of uncertainty.

  9. Simulation model for longterm management of Avena fatua L. in winter wheat

    Directory of Open Access Journals (Sweden)

    Jäck, Ortrud

    2014-02-01

    Full Text Available Decision support systems (DSS are used for weed control decisions worldwide. Several DSS for weed management have been published. However they mostly rely on full herbicide dosages and do not take weed population dynamics into account. We developed a modular DSS for long-term Avena fatua L. control in winter wheat. The DSS was parameterized with three year field experiment datasets covering yield loss data, densitydependent population dynamics data as well as data on dose dependent herbicide efficacy and dosedependent population dynamics. The DSS aims to control the A. fatua in the long run. Our hypothesis is that the optimized DSS reduces herbicide input while keeping the population density at low level, maintaining high grain yields and net return. The DSS comprises four sub-models calculating crop yield loss, A. fatua population dynamics as well as dose dependent herbicide efficacy and economics of the weed control decision. The economic sub-model calculates net return in dependency of the herbicide dosage and thus the resulting crop yield. First results of a 10-year simulation showed that herbicide input could be reduced by 40% compared to the economic threshold strategy, while the population density of A. fatua is controlled. Up to now the DSS has been parameterized for the herbicides Ralon Super, Axial 50 and Broadway. The results show the great potential of reducing herbicide input and point out the importance of including population dynamics models into DSS.

  10. Sea surface salinity and temperature-based predictive modeling of southwestern US winter precipitation: improvements, errors, and potential mechanisms

    Science.gov (United States)

    Liu, T.; Schmitt, R. W.; Li, L.

    2017-12-01

    Using 69 years of historical data from 1948-2017, we developed a method to globally search for sea surface salinity (SSS) and temperature (SST) predictors of regional terrestrial precipitation. We then applied this method to build an autumn (SON) SSS and SST-based 3-month lead predictive model of winter (DJF) precipitation in southwestern United States. We also find that SSS-only models perform better than SST-only models. We previously used an arbitrary correlation coefficient (r) threshold, |r| > 0.25, to define SSS and SST predictor polygons for best subset regression of southwestern US winter precipitation; from preliminary sensitivity tests, we find that |r| > 0.18 yields the best models. The observed below-average precipitation (0.69 mm/day) in winter 2015-2016 falls within the 95% confidence interval of the prediction model. However, the model underestimates the anomalous high precipitation (1.78 mm/day) in winter 2016-2017 by more than three-fold. Moisture transport mainly attributed to "pineapple express" atmospheric rivers (ARs) in winter 2016-2017 suggests that the model falls short on a sub-seasonal scale, in which case storms from ARs contribute a significant portion of seasonal terrestrial precipitation. Further, we identify a potential mechanism for long-range SSS and precipitation teleconnections: standing Rossby waves. The heat applied to the atmosphere from anomalous tropical rainfall can generate standing Rossby waves that propagate to higher latitudes. SSS anomalies may be indicative of anomalous tropical rainfall, and by extension, standing Rossby waves that provide the long-range teleconnections.

  11. Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

    International Nuclear Information System (INIS)

    Sonne, M R; Hattel, J H; Frandsen, J O

    2015-01-01

    In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than for the chill casting, resulting in a very course microstructure. From the simulations the nodule count is found to be 17 nodules per mm 2 and 159 nodules per mm 2 for the sand and chill casting, respectively, in the critical region of the main bearing seat. This is verified from nodule counts performed on the real cast main shafts. Residual stress evaluations show an overall increase of the maximum principal stress field for the chill casting, which is expected. However, the stresses are found to be in compression on the surface of the chill cast main shaft, which is unforeseen. (paper)

  12. Sensitivities of crop models to extreme weather conditions during flowering period demonstrated for maize and winter wheat in Austria

    Czech Academy of Sciences Publication Activity Database

    Eitzinger, Josef; Thaler, S.; Schmid, E.; Strauss, F.; Ferrise, R.; Moriondo, M.; Bindi, M.; Palosuo, T.; Rötter, R.; Kersebaum, K. C.; Olesen, J. E.; Patil, R. H.; Saylan, L.; Çaldag, B.; Caylak, O.

    2013-01-01

    Roč. 151, č. 6 (2013), s. 813-835 ISSN 0021-8596 R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : crop models * weather conditions * winter wheat * Austria Subject RIV: EH - Ecology, Behaviour Impact factor: 2.891, year: 2013

  13. The influence of winter convection on primary production: A parameterisation using a hydrostatic three-dimensional biogeochemical model

    DEFF Research Database (Denmark)

    Grosse, Fabian; Lindemann, Christian; Pätch, Johannes

    2014-01-01

    organic carbon. The carbon export during late winter/early spring significantly exceeded the export of the reference run. Furthermore, a non-hydrostatic convection model was used to evaluate the major assumption of the presented parameterisation which implies the matching of the mixed layer depth...

  14. Predicting Pre-planting Risk of Stagonospora nodorum blotch in Winter Wheat Using Machine Learning Models

    Directory of Open Access Journals (Sweden)

    Lucky eMehra

    2016-03-01

    Full Text Available Pre-planting factors have been associated with the late-season severity of Stagonospora nodorum blotch (SNB, caused by the fungal pathogen Parastagonospora nodorum, in winter wheat (Triticum aestivum. The relative importance of these factors in the risk of SNB has not been determined and this knowledge can facilitate disease management decisions prior to planting of the wheat crop. In this study, we examined the performance of multiple regression (MR and three machine learning algorithms namely artificial neural networks, categorical and regression trees, and random forests (RF in predicting the pre-planting risk of SNB in wheat. Pre-planting factors tested as potential predictor variables were cultivar resistance, latitude, longitude, previous crop, seeding rate, seed treatment, tillage type, and wheat residue. Disease severity assessed at the end of the growing season was used as the response variable. The models were developed using 431 disease cases (unique combinations of predictors collected from 2012 to 2014 and these cases were randomly divided into training, validation, and test datasets. Models were evaluated based on the regression of observed against predicted severity values of SNB, sensitivity-specificity ROC analysis, and the Kappa statistic. A strong relationship was observed between late-season severity of SNB and specific pre-planting factors in which latitude, longitude, wheat residue, and cultivar resistance were the most important predictors. The MR model explained 33% of variability in the data, while machine learning models explained 47 to 79% of the total variability. Similarly, the MR model correctly classified 74% of the disease cases, while machine learning models correctly classified 81 to 83% of these cases. Results show that the RF algorithm, which explained 79% of the variability within the data, was the most accurate in predicting the risk of SNB, with an accuracy rate of 93%. The RF algorithm could allow early

  15. Predicting Pre-planting Risk of Stagonospora nodorum blotch in Winter Wheat Using Machine Learning Models.

    Science.gov (United States)

    Mehra, Lucky K; Cowger, Christina; Gross, Kevin; Ojiambo, Peter S

    2016-01-01

    Pre-planting factors have been associated with the late-season severity of Stagonospora nodorum blotch (SNB), caused by the fungal pathogen Parastagonospora nodorum, in winter wheat (Triticum aestivum). The relative importance of these factors in the risk of SNB has not been determined and this knowledge can facilitate disease management decisions prior to planting of the wheat crop. In this study, we examined the performance of multiple regression (MR) and three machine learning algorithms namely artificial neural networks, categorical and regression trees, and random forests (RF), in predicting the pre-planting risk of SNB in wheat. Pre-planting factors tested as potential predictor variables were cultivar resistance, latitude, longitude, previous crop, seeding rate, seed treatment, tillage type, and wheat residue. Disease severity assessed at the end of the growing season was used as the response variable. The models were developed using 431 disease cases (unique combinations of predictors) collected from 2012 to 2014 and these cases were randomly divided into training, validation, and test datasets. Models were evaluated based on the regression of observed against predicted severity values of SNB, sensitivity-specificity ROC analysis, and the Kappa statistic. A strong relationship was observed between late-season severity of SNB and specific pre-planting factors in which latitude, longitude, wheat residue, and cultivar resistance were the most important predictors. The MR model explained 33% of variability in the data, while machine learning models explained 47 to 79% of the total variability. Similarly, the MR model correctly classified 74% of the disease cases, while machine learning models correctly classified 81 to 83% of these cases. Results show that the RF algorithm, which explained 79% of the variability within the data, was the most accurate in predicting the risk of SNB, with an accuracy rate of 93%. The RF algorithm could allow early assessment of

  16. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

    Directory of Open Access Journals (Sweden)

    S. Kalenderski

    2013-02-01

    Full Text Available We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ~2.4 Tg day−1 and ~1.5 Tg day−1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground- and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3–4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m−2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

  17. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

    KAUST Repository

    Kalenderski, Stoitchko

    2013-02-20

    We used WRF-Chem, a regional meteorological model coupled with an aerosol-chemistry component, to simulate various aspects of the dust phenomena over the Arabian Peninsula and Red Sea during a typical winter-time dust event that occurred in January 2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ?2.4 Tg day-1 and ?1.5 Tg day-1, corresponding to two periods with the highest aerosol optical depth that were well captured by ground-and satellite-based observations. The model predicted that the dust plume was thick, extensive, and mixed in a deep boundary layer at an altitude of 3-4 km. Its spatial distribution was modeled to be consistent with typical spatial patterns of dust emissions. We utilized MODIS-Aqua and Solar Village AERONET measurements of the aerosol optical depth (AOD) to evaluate the radiative impact of aerosols. Our results clearly indicated that the presence of dust particles in the atmosphere caused a significant reduction in the amount of solar radiation reaching the surface during the dust event. We also found that dust aerosols have significant impact on the energy and nutrient balances of the Red Sea. Our results showed that the simulated cooling under the dust plume reached 100 W m-2, which could have profound effects on both the sea surface temperature and circulation. Further analysis of dust generation and its spatial and temporal variability is extremely important for future projections and for better understanding of the climate and ecological history of the Red Sea.

  18. Using species distribution model to estimate the wintering population size of the endangered scaly-sided merganser in China.

    Directory of Open Access Journals (Sweden)

    Qing Zeng

    Full Text Available Scaly-sided Merganser is a globally endangered species restricted to eastern Asia. Estimating its population is difficult and considerable gap exists between populations at its breeding grounds and wintering sites. In this study, we built a species distribution model (SDM using Maxent with presence-only data to predict the potential wintering habitat for Scaly-sided Merganser in China. Area under the receiver operating characteristic curve (AUC method suggests high predictive power of the model (training and testing AUC were 0.97 and 0.96 respectively. The most significant environmental variables included annual mean temperature, mean temperature of coldest quarter, minimum temperature of coldest month and precipitation of driest quarter. Suitable conditions for Scaly-sided Merganser are predicted in the middle and lower reaches of the Yangtze River, especially in Jiangxi, Hunan and Hubei Provinces. The predicted suitable habitat embraces 6,984 km of river. Based on survey results from three consecutive winters (2010-2012 and previous studies, we estimated that the entire wintering population of Scaly-sided Merganser in China to be 3,561 ± 478 individuals, which is consistent with estimate in its breeding ground.

  19. Modelling and Evaluation of Non-Linear Rootwater Uptake for Winter Cropping of Wheat and Berseem

    Science.gov (United States)

    GS, K.; Prasad, K. S. H.

    2017-12-01

    The plant water uptake is significant for study to monitor the irrigation supplied to the plant. The Richards equation has been the key governing equation to quantify the root water uptake in the vadose zone and it takes all the sources and sink terms into consideration. The β parameter or the non linearity parameter is used in this modeling to bring the non linearity in the plant root water uptake. The soil parameters are obtained by experimentation and are employed in the Van-Genuchten equation for soil moisture study. Field experiments were carried out at Civil Engineering Department IIT Roorkee, Uttarakhand, India, during the winter season of 2013 and 2014 for berseem and 2016 for wheat as per the local cropping practices. Drainage type lysimeters were installed to study the soil water balance. Soil moisture was monitored using profile probe. Precipitation and all meteorological data were obtained from the nearby gauges located at the National Institute of Hydrology, Roorkee.The moisture data and the deep percolation data were collected on a daily basis and the irrigation supply was controlled and monitored to satisfy the moisture requirements of the crops respectively.In order to study the effect of water scarcity on the crops, the plot was divided and deficited irrigation was applied for the second cropping season for Berseem.The yields for both the seasons was also measured. The solution of Richards equation as applied to the moisture movement in the root zone was modeled. For estimation of root water uptake, the governing equation is the one-dimensional mixed form of Richards' equation is employed (Ji et al., 2007; Shankar et al., 2012).The sink term in the model accounts for the root water uptake, which is utilized by the plant for transpiration. Smaxor the maximum root water uptake for the root zone on a given day must be equal to the maximum transpiration on the corresponding day The model computed moisture content and pressure head is calibrated with

  20. External tank chill effect on the space transportation system launch pad environment

    Science.gov (United States)

    Ahmad, R. A.; Boraas, S.

    1991-01-01

    The external tank (ET) of the STS contains liquid oxygen and liquid hydrogen as oxidizer and fuel for the SSMEs. Once the cryogen have been loaded into the ET, the temperature of the air surrounding the STS is chilled by the cold outer surface of the ET. This paper describes a two-dimensional flow and thermal analysis to determine this chill effect on the STS launch pad environment subsequent to the ET loading operation. The analysis was done assuming winter conditions and a northwest wind direction. An existing CFD code, PHOENICS '81, was used in the study. The results are presented as local and average values of the heat transfer coefficient, the Nusselt number, and the surface temperature around the redesigned solid rocket motors (RSRMs) and the ET. The temperature depression caused by the ET chilling of the air in the vicinity of the RSRMs was calculated to be 3 F below the ambient. This compares with the observed 1-2 F RSRM surface temperature depression based upon measurements made prior to the winter flight of STS-29. Since the surface temperature would be expected to be slightly higher than the local air temperature, the predicted temperature depression of the air appears to be substantiated.

  1. Modeling of meteorology, chemistry and aerosol for the 2017 Utah Winter Fine Particle Study

    Science.gov (United States)

    McKeen, S. A.; Angevine, W. M.; McDonald, B.; Ahmadov, R.; Franchin, A.; Middlebrook, A. M.; Fibiger, D. L.; McDuffie, E. E.; Womack, C.; Brown, S. S.; Moravek, A.; Murphy, J. G.; Trainer, M.

    2017-12-01

    The Utah Winter Fine Particle Study (UWFPS-17) field project took place during January and February of 2017 within the populated region of the Great Salt Lake, Utah. The study focused on understanding the meteorology and chemistry associated with high particulate matter (PM) levels often observed near Salt Lake City during stable wintertime conditions. Detailed composition and meteorological observations were taken from the NOAA Twin-Otter aircraft and several surface sites during the study period, and extremely high aerosol conditions were encountered for two cold-pool episodes occurring in the last 2 weeks of January. A clear understanding of the photochemical and aerosol processes leading to these high PM events is still lacking. Here we present high spatiotemporal resolution simulations of meteorology, PM and chemistry over Utah from January 13 to February 1, 2017 using the WRF/Chem photochemical model. Correctly characterizing the meteorology is difficult due to the complex terrain and shallow inversion layers. We discuss the approach and limitations of the simulated meteorology, and evaluate low-level pollutant mixing using vertical profiles from missed airport approaches by the NOAA Twin-Otter performed routinely during each flight. Full photochemical simulations are calculated using NOx, ammonia and VOC emissions from the U.S. EPA NEI-2011 emissions inventory. Comparisons of the observed vertical column amounts of NOx, ammonia, aerosol nitrate and ammonium with model results shows the inventory estimates for ammonia emissions are low by a factor of four and NOx emissions are low by nearly a factor of two. The partitioning of both nitrate and NH3 between gas and particle phase depends strongly on the NH3 and NOx emissions to the model and calculated NOx to nitrate conversion rates. These rates are underestimated by gas-phase chemistry alone, even though surface snow albedo increases photolysis rates by nearly a factor of two. Several additional conversion

  2. Raw-appearing Restructured fish models made with Sodium alginate or Microbial transglutaminase and effect of chilled storage Reestrutura do modelo peixe feito com transglutaminase alginato de sódio e microbiana e o efeito do armazenamento refrigerado

    Directory of Open Access Journals (Sweden)

    Helena Moreno

    2013-03-01

    Full Text Available Restructuring by adding Sodium Alginate or Microbial Transglutaminase (MTGase using cold gelation technology make it possible to obtain many different raw products from minced and/or chopped fish muscle that are suitable for being used as the basis of new restructured products with different physicochemical properties and even different compositions. Special consideration must be given to their shelf-life and the changes that may take place during chilling, both in visual appearance and physicochemical properties. After chilled storage, the restructured models made with different muscular particle size and composition at low temperature (5 °C, it was observed that microbial growth limited the shelf-life to 7-14 days. Mechanical properties increased (p 0.05 was detected during storage.A reestruturação pela adição de Alginato de sódio ou Transglutaminase microbiana (MTGase utilizando a tecnologia de gelificação pelo frio torna possível a obtenção de diversos produtos crus, a partir de músculo de peixe picado, que são apropriados para serem usados como base de novos produtos reestruturados com diferentes propriedades físico-químicas e até com composições diferentes. Consideração especial deve ser dada ao prazo de validade e às mudanças que podem ocorrer durante a refrigeração, tanto no aspecto visual como nas propriedades físico-químicas. Após o armazenamento refrigerado de modelos reestruturados feitos com diferentes tamanhos de partículas musculares e composições a baixas temperaturas (5 °C, foi observado um crescimento microbiano que limita o prazo de validade para 7 a 14 dias. As propriedades mecânicas aumentaram (p < 0,05 durante o tempo, e os valores mais altos foram mais observados nas amostras elaboradas unindo partículas de músculo de tamanho pequeno do que nas elaboradas por homogeneização. O rendimento após cozimento e a perda de purga não apresentaram uma evolução clara nem foi detectada qualquer

  3. Investigating added value of regional climate modeling in North American winter storm track simulations

    Science.gov (United States)

    Poan, E. D.; Gachon, P.; Laprise, R.; Aider, R.; Dueymes, G.

    2018-03-01

    Extratropical Cyclone (EC) characteristics depend on a combination of large-scale factors and regional processes. However, the latter are considered to be poorly represented in global climate models (GCMs), partly because their resolution is too coarse. This paper describes a framework using possibilities given by regional climate models (RCMs) to gain insight into storm activity during winter over North America (NA). Recent past climate period (1981-2005) is considered to assess EC activity over NA using the NCEP regional reanalysis (NARR) as a reference, along with the European reanalysis ERA-Interim (ERAI) and two CMIP5 GCMs used to drive the Canadian Regional Climate Model—version 5 (CRCM5) and the corresponding regional-scale simulations. While ERAI and GCM simulations show basic agreement with NARR in terms of climatological storm track patterns, detailed bias analyses show that, on the one hand, ERAI presents statistically significant positive biases in terms of EC genesis and therefore occurrence while capturing their intensity fairly well. On the other hand, GCMs present large negative intensity biases in the overall NA domain and particularly over NA eastern coast. In addition, storm occurrence over the northwestern topographic regions is highly overestimated. When the CRCM5 is driven by ERAI, no significant skill deterioration arises and, more importantly, all storm characteristics near areas with marked relief and over regions with large water masses are significantly improved with respect to ERAI. Conversely, in GCM-driven simulations, the added value contributed by CRCM5 is less prominent and systematic, except over western NA areas with high topography and over the Western Atlantic coastlines where the most frequent and intense ECs are located. Despite this significant added-value on seasonal-mean characteristics, a caveat is raised on the RCM ability to handle storm temporal `seriality', as a measure of their temporal variability at a given

  4. Winter is losing its cool

    Science.gov (United States)

    Feng, S.

    2017-12-01

    Winter seasons have significant societal impacts across all sectors ranging from direct human health to ecosystems, transportation, and recreation. This study quantifies the severity of winter and its spatial-temporal variations using a newly developed winter severity index and daily temperature, snowfall and snow depth. The winter severity and the number of extreme winter days are decreasing across the global terrestrial areas during 1901-2015 except the southeast United States and isolated regions in the Southern Hemisphere. These changes are dominated by winter warming, while the changes in daily snowfall and snow depth played a secondary role. The simulations of multiple CMIP5 climate models can well capture the spatial and temporal variations of the observed changes in winter severity and extremes during 1951-2005. The models are consistent in projecting a future milder winter under various scenarios. The winter severity is projected to decrease 60-80% in the middle-latitude Northern Hemisphere under the business-as-usual scenario. The winter arrives later, ends earlier and the length of winter season will be notably shorter. The changes in harsh winter in the polar regions are weak, mainly because the warming leads to more snowfall in the high latitudes.

  5. Predicting pre-planting risk of Stagonospora nodorum blotch in winter wheat using machine learning models

    Science.gov (United States)

    Pre-planting factors have been associated with the late-season severity of Stagonospora nodorum blotch (SNB), caused by the fungal pathogen Parastagonospora nodorum, in winter wheat (Triticum aestivum). The relative importance of these factors in the risk of SNB has not been determined and this know...

  6. The inheritance of chilling tolerance in tomato (Lycopersicon spp.)

    NARCIS (Netherlands)

    Venema, JH; Linger, P; van Heusden, AW; van Hasselt, PR; Brueggemann, W

    During the past 25 years, chilling tolerance of the cultivated (chilling-sensitive) tomato Lycopersicon esculentum and its wild, chilling-tolerant relatives L. peruvianum and L. hirsutum (and, less intensively studied, L. chilense) has been the object of several investigations. The final aim of

  7. 77 FR 10772 - Fresh and Chilled Atlantic Salmon From Norway

    Science.gov (United States)

    2012-02-23

    ... and Chilled Atlantic Salmon From Norway Determination On the basis of the record \\1\\ developed in the... countervailing duty order and antidumping duty order on fresh and chilled Atlantic salmon from Norway would not... and Chilled Atlantic Salmon from Norway: Investigation Nos. 701-TA-302 and 731-TA-454 (Third Review...

  8. The use of phenological data to calculate chilling units in Olea europaea L. in relation to the onset of reproduction

    Science.gov (United States)

    Orlandi, F.; Fornaciari, M.; Romano, B.

    2002-02-01

    The aim of this study was to develop a practical method to evaluate the effective relationship between the amount of winter chilling and the response expressed as the spring reproductive re-starting dates in the olive ( Olea europaea L.). Two olive cultivars growing in a special olive orchard in Umbria (central Italy) were studied over a 3-year period (1998-2000): the cultivar Ascolana, typical of central Italy, and the cultivar Giarraffa, typical of southern Italy. The spring reproductive re-starts were assessed using data from detailed phenological observations made on 60 trees of each cultivar in an effort to establish the exact date of reproductive bud swelling. The chilling phenomenon was evaluated by using 341 functions derived from a formula developed by researchers at Utah State University to calculate chilling units. The mathematical functions are defined, and show the very close relationship between the amount of winter chilling and the spring reproductive response in the two cultivars in the orchard studied. The results can be used to define the relationship between local climate and plant development, and the mathematical approach can be used to draw maps that can show the suitability of different cultivars on the basis of local climatic conditions.

  9. Winter radiation extinction and reflection in a boreal pine canopy: measurements and modelling

    International Nuclear Information System (INIS)

    Pomeroy, J.W.; Dion, K.

    1996-01-01

    Predicting the rate of snow melt and intercepted snow sublimation in boreal forests requires an understanding of the effects of snow-covered conifers on the exchange of radiant energy. This study examined the amount of intercepted snow on a jack pine canopy in the boreal forest of central Saskatchewan and the shortwave and net radiation exchange with this canopy, to determine the effect of intercepted snow and canopy structure on shortwave radiation reflection and extinction and net radiation attenuation in a boreal forest. The study focused on clear sky conditions, which are common during winter in the continental boreal forest. Intercepted snow was found to have no influence on the clear-sky albedo of the canopy, the extinction of short wave radiation by the canopy or ratio of net radiation at the canopy top to that at the surface snow cover. Because of the low albedo of the snow-covered canopy, net radiation at the canopy top remains positive and a large potential source of energy for sublimation. The canopy albedo declines somewhat as the extinction efficiency of the underlying canopy increases. The extinction efficiency of short wave radiation in the canopy depends on solar angle because of the approximately horizontal orientation of pine branches. For low solar angles above the horizon, the extinction efficiency is quite low and short wave transmissivity through the canopy is relatively high. As the solar angle increases, extinction increases up to angles of about 50°, and then declines. Extinction of short wave radiation in the canopy strongly influences the attenuation of net radiation by the canopy. Short wave radiation that is extinguished by branches is radiated as long wave, partly downwards to the snow cover. The ratio of net radiation at the canopy top to that at the snow cover surface increases with the extinction of short wave radiation and is negative for low extinction efficiencies. For the pine canopy examined, the daily mean net radiation at

  10. Simulation of Wild oat (Avena ludoviciana L. Competition on Winter Wheat (Triticum astivum Growth and Yield. I: Model Description and Validation

    Directory of Open Access Journals (Sweden)

    F Mondani

    2015-09-01

    Full Text Available Crop growth models could stimulate growth and development based on science principles and mathematical equations. They also able to evaluate effects of climate, soil, water and agronomic management practices on crop yield. In the present study, an eco-physiological simulation model developed to assess wild oat damage to winter wheat growth and yield. The general structure of this model is derived from LINTUL1 model which modified to wild oat competition against winter wheat. LINTUL1 model was developed for simulation of spring wheat potential production level. In this study, first, we added development stage (DVS and vernalization to LINTUL1 for simulation of winter wheat growth and development and then the model calibrated for potential production level. Finally, we incorporate harmful effects of wild oat to winter wheat growth and yield. Weather data used as input were average daily minimum and maximum temperature (°C and daily global radiation (MJ m-2 in Mashhad, Iran. Parameter values were derived from the literature. The model is written in Fortran Simulation Translator (FST programming language and then validated based on an experiment data. For these purposes different wild oat plant densities were arranged. The data of this experiment does not use for calibration. The results showed that this model was in general able to simulate the temporal changes in DVS of winter wheat and wild oat, total dry matter (TDM of winter wheat and wild oat and yield loss of wheat due to wild oat competition in all treatments, satisfactorily. Root mean square error (RMSE for winter wheat DVS, wild oat DVS, average winter wheat TDM, average wild oat TDM, and yield loss of winter wheat was 10.4, 14.5, 5.8, 7.6 and 7.5, respectively.

  11. Winter Radiation Extinction and Reflection in a Boreal Pine Canopy: Measurements and Modelling

    Science.gov (United States)

    Pomeroy, J. W.; Dion, K.

    1996-12-01

    Predicting the rate of snowmelt and intercepted snow sublimation in boreal forests requires an understanding of the effects of snow-covered conifers on the exchange of radiant energy. This study examined the amount of intercepted snow on a jack pine canopy in the boreal forest of central Saskatchewan and the shortwave and net radiation exchange with this canopy, to determine the effect of intercepted snow and canopy structure on shortwave radiation reflection and extinction and net radiation attenuation in a boreal forest. The study focused on clear sky conditions, which are common during winter in the continental boreal forest. Intercepted snow was found to have no influence on the clear-sky albedo of the canopy, the extinction of short wave radiation by the canopy or ratio of net radiation at the canopy top to that at the surface snow cover. Because of the low albedo of the snow-covered canopy, net radiation at the canopy top remains positive and a large potential source of energy for sublimation. The canopy albedo declines somewhat as the extinction efficiency of the underlying canopy increases. The extinction efficiency of short wave radiation in the canopy depends on solar angle because of the approximately horizontal orientation of pine branches. For low solar angles above the horizon, the extinction efficiency is quite low and short wave transmissivity through the canopy is relatively high. As the solar angle increases, extinction increases up to angles of about 50̂, and then declines. Extinction of short wave radiation in the canopy strongly influences the attenuation of net radiation by the canopy. Short wave radiation that is extinguished by branches is radiated as long wave, partly downwards to the snow cover. The ratio of net radiation at the canopy top to that at the snow cover surface increases with the extinction of short wave radiation and is negative for low extinction efficiencies. For the pine canopy examined, the daily mean net radiation at the

  12. Guns on Campus: A Chilling Effect

    Science.gov (United States)

    Mash, Kenneth M.

    2013-01-01

    The author of this article observes that, while much has been written on the overall topic of safety with regard to allowing guns on college campuses, little has been said about how allowing the possession of deadly weapons can create a "chilling effect" on academic discussions. This article considers how some universities have…

  13. Chilled ammonia process for CO2 capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; van Well, Willy J. M

    2009-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2-10 degrees C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows...

  14. Chilled Ammonia Process for CO2 Capture

    DEFF Research Database (Denmark)

    Darde, Victor Camille Alfred; Thomsen, Kaj; Well, Willy J.M. van

    2010-01-01

    The chilled ammonia process absorbs the CO2 at low temperature (2–10°C). The heat of absorption of carbon dioxide by ammonia is significantly lower than for amines. In addition, degradation problems can be avoided and a high carbon dioxide capacity is achieved. Hence, this process shows good...

  15. Yield response of winter wheat cultivars to environments modeled by different variance-covariance structures in linear mixed models

    Energy Technology Data Exchange (ETDEWEB)

    Studnicki, M.; Mądry, W.; Noras, K.; Wójcik-Gront, E.; Gacek, E.

    2016-11-01

    The main objectives of multi-environmental trials (METs) are to assess cultivar adaptation patterns under different environmental conditions and to investigate genotype by environment (G×E) interactions. Linear mixed models (LMMs) with more complex variance-covariance structures have become recognized and widely used for analyzing METs data. Best practice in METs analysis is to carry out a comparison of competing models with different variance-covariance structures. Improperly chosen variance-covariance structures may lead to biased estimation of means resulting in incorrect conclusions. In this work we focused on adaptive response of cultivars on the environments modeled by the LMMs with different variance-covariance structures. We identified possible limitations of inference when using an inadequate variance-covariance structure. In the presented study we used the dataset on grain yield for 63 winter wheat cultivars, evaluated across 18 locations, during three growing seasons (2008/2009-2010/2011) from the Polish Post-registration Variety Testing System. For the evaluation of variance-covariance structures and the description of cultivars adaptation to environments, we calculated adjusted means for the combination of cultivar and location in models with different variance-covariance structures. We concluded that in order to fully describe cultivars adaptive patterns modelers should use the unrestricted variance-covariance structure. The restricted compound symmetry structure may interfere with proper interpretation of cultivars adaptive patterns. We found, that the factor-analytic structure is also a good tool to describe cultivars reaction on environments, and it can be successfully used in METs data after determining the optimal component number for each dataset. (Author)

  16. Improving winter leaf area index estimation in evergreen coniferous forests and its significance in carbon and water fluxes modeling

    Science.gov (United States)

    Wang, R.; Chen, J. M.; Luo, X.

    2016-12-01

    Modeling of carbon and water fluxes at the continental and global scales requires remotely sensed LAI as inputs. For evergreen coniferous forests (ENF), severely underestimated winter LAI has been one of the issues for mostly available remote sensing products, which could cause negative bias in the modeling of Gross Primary Productivity (GPP) and evapotranspiration (ET). Unlike deciduous trees which shed all the leaves in winter, conifers retains part of their needles and the proportion of the retained needles depends on the needle longevity. In this work, the Boreal Ecosystem Productivity Simulator (BEPS) was used to model GPP and ET at eight FLUXNET Canada ENF sites. Two sets of LAI were used as the model inputs: the 250m 10-day University of Toronto (U of T) LAI product Version 2 and the corrected LAI based on the U of T LAI product and the needle longevity of the corresponding tree species at individual sites. Validating model daily GPP (gC/m2) against site measurements, the mean RMSE over eight sites decreases from 1.85 to 1.15, and the bias changes from -0.99 to -0.19. For daily ET (mm), mean RMSE decreases from 0.63 to 0.33, and the bias changes from -0.31 to -0.16. Most of the improvements occur in the beginning and at the end of the growing season when there is large correction of LAI and meanwhile temperature is still suitable for photosynthesis and transpiration. For the dormant season, the improvement in ET simulation mostly comes from the increased interception of precipitation brought by the elevated LAI during that time. The results indicate that model performance can be improved by the application the corrected LAI. Improving the winter RS LAI can make a large impact on land surface carbon and energy budget.

  17. A study on the kinetic behavior of Listeria monocytogenes in ice cream stored under static and dynamic chilling and freezing conditions.

    Science.gov (United States)

    Gougouli, M; Angelidis, A S; Koutsoumanis, K

    2008-02-01

    The kinetic behavior of Listeria monocytogenes in 2 commercial ice cream products (A and B) that were inoculated and stored under static chilling (4 to 16 degrees C), static freezing (-5 to -33 degrees C), dynamic chilling, and dynamic chilling-freezing conditions was studied, simulating conditions of the aging process and of normal or abuse conditions during distribution and storage. The ice cream products A and B had different compositions but similar pH (6.50 and 6.67, respectively) and water activity (0.957 and 0.965, respectively) values. For both chilling and freezing conditions, the kinetic behavior of the pathogen was similar in the 2 products, indicating that the pH and water activity, together with temperature, were the main factors controlling growth. Under chilling conditions, L. monocytogenes grew well at all temperatures tested. Under freezing conditions, no significant changes in the population of the pathogen were observed throughout a 90-d storage period for either of the inoculum levels tested (10(3) and 10(6) cfu/g). Growth data from chilled storage conditions were fitted to a mathematical model, and the calculated maximum specific growth rate was modeled as a function of temperature by using a square root model. The model was further validated under dynamic chilling and dynamic chilling-freezing conditions by using 4 different storage temperature scenarios. Under dynamic chilling conditions, the model accurately predicted the growth of the pathogen in both products, with 99.5% of the predictions lying within the +/- 20% relative error zone. The results from the chilling-freezing storage experiments showed that the pathogen was able to initiate growth within a very short time after a temperature upshift from freezing to chilling temperatures. This indicates that the freezing conditions did not cause a severe stress in L. monocytogenes cells capable of leading to a significant "additional" lag phase during the subsequent growth of the pathogen at

  18. The 2009–2010 Arctic stratospheric winter – general evolution, mountain waves and predictability of an operational weather forecast model

    Directory of Open Access Journals (Sweden)

    A. Dörnbrack

    2012-04-01

    Full Text Available The relatively warm 2009–2010 Arctic winter was an exceptional one as the North Atlantic Oscillation index attained persistent extreme negative values. Here, selected aspects of the Arctic stratosphere during this winter inspired by the analysis of the international field experiment RECONCILE are presented. First of all, and as a kind of reference, the evolution of the polar vortex in its different phases is documented. Special emphasis is put on explaining the formation of the exceptionally cold vortex in mid winter after a sequence of stratospheric disturbances which were caused by upward propagating planetary waves. A major sudden stratospheric warming (SSW occurring near the end of January 2010 concluded the anomalous cold vortex period. Wave ice polar stratospheric clouds were frequently observed by spaceborne remote-sensing instruments over the Arctic during the cold period in January 2010. Here, one such case observed over Greenland is analysed in more detail and an attempt is made to correlate flow information of an operational numerical weather prediction model to the magnitude of the mountain-wave induced temperature fluctuations. Finally, it is shown that the forecasts of the ECMWF ensemble prediction system for the onset of the major SSW were very skilful and the ensemble spread was very small. However, the ensemble spread increased dramatically after the major SSW, displaying the strong non-linearity and internal variability involved in the SSW event.

  19. Energetic optimization of the chilled water systems operation at hotels

    Directory of Open Access Journals (Sweden)

    Reineris Montero Laurencio

    2015-12-01

    Full Text Available The hotel exploitation, while continuing to satisfy the customers, needs to decrease the requests of electric power as the principal energy carrier. Solving issues regarding the occupation of a hotel integrally, taking the air conditioning as center of attention, which demands the bigger consumptions of electricity, results in a complex task. To solve this issue, a procedure was implemented to optimize the operation of the water-chilled systems. The procedure integrates an energy model with a strategy of low occupation following energetic criteria based on combinatorial-evolutionary criteria. To classify the information, the formulation of the tasks and the synthesis of the solutions, a methodology of analysis and synthesis of engineering is used. The energetic model considers the variability of the local climatology and the occupation of the selected rooms, and includes: the thermal model of the building obtained by means of artificial neural networks, the hydraulic model and the model of the compression work. These elements allow to find the variable of decision occupation, performing intermediate calculations to obtain the velocity of rotation in the centrifugal pump and the output temperature of the cooler water, minimizing the requirements of electric power in the water-chilled systems. To evaluate the states of the system, a combinatorial optimization is used through the following methods: simple exhaustive, stepped exhaustive or genetic algorithm depending on the quantity of variants of occupation. All calculation tasks and algorithms of the procedure were automated through a computer application.

  20. Involvement of Polyamines in the Chilling Tolerance of Cucumber Cultivars

    Science.gov (United States)

    Shen, Wenyun; Nada, Kazuyoshi; Tachibana, Shoji

    2000-01-01

    The possible involvement of polyamines (PAs) in the chilling tolerance of cucumber (Cucumis sativus L. cv Jinchun No. 3 and cv Suyo) was investigated. Plants with the first expanded leaves were exposed to 3°C or 15°C in the dark for 24 h (chilling), and then transferred to 28°C/22°C under a 12-h photoperiod for another 24 h (rewarming). Chilling-tolerant cv Jinchun No. 3 showed a marked increase of free spermidine (Spd) in leaves, once during chilling and again during rewarming. Putrescine increased significantly during rewarming, but the increase of spermine was slight. Any of these PAs did not increase in chilling-sensitive cv Suyo during either period. PA-biosynthetic enzyme activities appear to mediate these differences between cultivars. Pretreatment of Spd to cv Suyo prevented chill-induced increases in the contents of hydrogen peroxide in leaves and activities of NADPH oxidases and NADPH-dependent superoxide generation in microsomes and alleviated chilling injury. Pretreatment of methylglyoxal-bis-(guanylhydrazone), a PA biosynthesis inhibitor, to chilled cv Jinchun No. 3 prevented Spd increase and enhanced microsomal NADPH oxidase activity and chilling injury. The results suggest that Spd plays important roles in chilling tolerance of cucumber, probably through prevention of chill-induced activation of NADPH oxidases in microsomes. PMID:10982456

  1. Winter Wonderlands

    Science.gov (United States)

    Coy, Mary

    2011-01-01

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

  2. Modelling the economic losses of historic and present-day high-impact winter storms in Switzerland

    Science.gov (United States)

    Welker, Christoph; Stucki, Peter; Bresch, David; Dierer, Silke; Martius, Olivia; Brönnimann, Stefan

    2014-05-01

    Severe winter storms such as "Vivian" in February 1990 and "Lothar" in December 1999 are among the most destructive meteorological hazards in Switzerland. Disaster severity resulting from such windstorms is attributable, on the one hand, to hazardous weather conditions such as high wind gust speeds; and on the other hand to socio-economic factors such as population density, distribution of values at risk, and damage susceptibility. For present-day winter storms, the data basis is generally good to describe the meteorological development and wind forces as well as the associated socio-economic impacts. In contrast, the information on historic windstorms is overall sparse and the available historic weather and loss reports mostly do not provide quantitative information. This study illustrates a promising technique to simulate the economic impacts of both historic and present winter storms in Switzerland since end of the 19th century. Our approach makes use of the novel Twentieth Century Reanalysis (20CR) spanning 1871-present. The 2-degree spatial resolution of the global 20CR dataset is relatively coarse. Thus, the complex orography of Switzerland is not realistically represented, which has considerable ramifications for the representation of wind systems that are strongly influenced by the local orography, such as Föhn winds. Therefore, a dynamical downscaling of the 20CR to 3 km resolution using the Weather Research and Forecasting (WRF) model was performed, for in total 40 high-impact winter storms in Switzerland since 1871. Based on the downscaled wind gust speeds and the climada loss model, the estimated economic losses were calculated at municipality level for current economic and social conditions. With this approach, we find an answer to the question what would be the economic losses of e.g. a hazardous Föhn storm - which occurred in northern Switzerland in February 1925 - today, i.e. under current socio-economic conditions. Encouragingly, the pattern of

  3. Comparison of residual stresses in sand- and chill casting of ductile cast iron wind turbine main shafts

    DEFF Research Database (Denmark)

    Sonne, Mads Rostgaard; Frandsen, J. O.; Hattel, Jesper Henri

    2015-01-01

    In this work, simulations of pouring, solidification and cooling, and residual stress evolution of sand and chill cast wind turbine main shafts is performed. The models are made in the commercial software MAGMAsoft. As expected, the cooling rate of the sand casting is shown to be much lower than...... for the chill casting, resulting in a very course microstructure.From the simulations the nodule count is found to be 17 nodules per mm2 and 159 nodules permm2 for the sand and chill casting, respectively, in the critical region of the main bearing seat.This is verified from nodule counts performed on the real...... cast main shafts. Residual stressevaluations show an overall increase of the maximum principal stress field for the chill casting,which is expected. However, the stresses are found to be in compression on the surface of thechill cast main shaft, which is unforeseen....

  4. The Year Without a Ski Season: An Analysis of the Winter of 2015 for Three Ski Resorts in Western Canada Using Historical and Simulation Model Forecasted Climate Data

    Science.gov (United States)

    Pidwirny, M. J.; Goode, J. D.; Pedersen, S.

    2015-12-01

    The winter of 2015 will go down as "the year without a ski season" for many ski resorts located close to the west coast of Canada and the USA. During this winter season, a large area of the eastern North Pacific Ocean had extremely high sea surface temperatures. These high sea surface temperatures influenced weather patterns on the west coast of North America producing very mild temperatures inland. Further, in alpine environments precipitation that normally arrives in the form of snow instead fell as rain. This research examines the climate characteristics of the winter of 2015 in greater detail for three ski resorts in British Columbia, Canada: Mount Washington, Cypress Mountain and Hemlock Valley. For these resorts, historical (1901 to 2013) and IPCC AR5 climate model forecasted climate data (RCP8.5 for 2025, 2055, and 2085) was generated for the variable winter degree days climate database ClimateBC. A value for winter degree days climate data at nearby meteorological stations for comparative analysis. For all three resorts, the winter of 2015 proved to be warmer than any individual year in the period 1901 to 2013. Interpolations involving the multi-model ensemble forecast means suggest that the climate associated with winter of 2015 will become the average normal for these resorts in only 35 to 45 years under the RCP8.5 emission scenario.

  5. [Prediction model of meteorological grade of wheat stripe rust in winter-reproductive area, Sichuan Basin, China].

    Science.gov (United States)

    Guo, Xiang; Wang, Ming Tian; Zhang, Guo Zhi

    2017-12-01

    The winter reproductive areas of Puccinia striiformis var. striiformis in Sichuan Basin are often the places mostly affected by wheat stripe rust. With data on the meteorological condition and stripe rust situation at typical stations in the winter reproductive area in Sichuan Basin from 1999 to 2016, this paper classified the meteorological conditions inducing wheat stripe rust into 5 grades, based on the incidence area ratio of the disease. The meteorological factors which were biologically related to wheat stripe rust were determined through multiple analytical methods, and a meteorological grade model for forecasting wheat stripe rust was created. The result showed that wheat stripe rust in Sichuan Basin was significantly correlated with many meteorological factors, such as the ave-rage (maximum and minimum) temperature, precipitation and its anomaly percentage, relative humidity and its anomaly percentage, average wind speed and sunshine duration. Among these, the average temperature and the anomaly percentage of relative humidity were the determining factors. According to a historical retrospective test, the accuracy of the forecast based on the model was 64% for samples in the county-level test, and 89% for samples in the municipal-level test. In a meteorological grade forecast of wheat stripe rust in the winter reproductive areas in Sichuan Basin in 2017, the prediction was accurate for 62.8% of the samples, with 27.9% error by one grade and only 9.3% error by two or more grades. As a result, the model could deliver satisfactory forecast results, and predicate future wheat stripe rust from a meteorological point of view.

  6. Prediction of winter wheat high yield from remote sensing based model: application in United States and Ukraine

    Science.gov (United States)

    Franch, B.; Vermote, E.; Roger, J. C.; Skakun, S.; Becker-Reshef, I.; Justice, C. O.

    2017-12-01

    Accurate and timely crop yield forecasts are critical for making informed agricultural policies and investments, as well as increasing market efficiency and stability. In Becker-Reshef et al. (2010) and Franch et al. (2015) we developed an empirical generalized model for forecasting winter wheat yield. It is based on the relationship between the Normalized Difference Vegetation Index (NDVI) at the peak of the growing season and the Growing Degree Day (GDD) information extracted from NCEP/NCAR reanalysis data. These methods were applied to MODIS CMG data in Ukraine, the US and China with errors around 10%. However, the NDVI is saturated for yield values higher than 4 MT/ha. As a consequence, the model had to be re-calibrated in each country and the validation of the national yields showed low correlation coefficients. In this study we present a new model based on the extrapolation of the pure wheat signal (100% of wheat within the pixel) from MODIS data at 1km resolution and using the Difference Vegetation Index (DVI). The model has been applied to monitor the national yield of winter wheat in the United States and Ukraine from 2001 to 2016.

  7. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with the TEB model

    Science.gov (United States)

    Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

    2016-02-01

    Snowfall forecasts help winter maintenance of road networks, ensure better coordination between services, cost control, and a reduction in environmental impacts caused by an inappropriate use of de-icers. In order to determine the possible accumulation of snow on pavements, forecasting the road surface temperature (RST) is mandatory. Weather outstations are used along these networks to identify changes in pavement status, and to make forecasts by analyzing the data they provide. Physical numerical models provide such forecasts, and require an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with two approaches to evaluate traffic incidence on RST. Experiments were then conducted to measure the effect of traffic on RST increase with respect to non-circulated areas. These field data were then used for comparison with the forecast provided by this traffic-implemented TEB version.

  8. Accounting for anthropic energy flux of traffic in winter urban road surface temperature simulations with TEB model

    Science.gov (United States)

    Khalifa, A.; Marchetti, M.; Bouilloud, L.; Martin, E.; Bues, M.; Chancibaut, K.

    2015-06-01

    A forecast of the snowfall helps winter coordination operating services, reducing the cost of the maintenance actions, and the environmental impacts caused by an inappropriate use of de-icing. In order to determine the possible accumulation of snow on pavement, the forecast of the road surface temperature (RST) is mandatory. Physical numerical models provide such forecast, and do need an accurate description of the infrastructure along with meteorological parameters. The objective of this study was to build a reliable urban RST forecast with a detailed integration of traffic in the Town Energy Balance (TEB) numerical model for winter maintenance. The study first consisted in generating a physical and consistent description of traffic in the model with all the energy interactions, with two approaches to evaluate the traffic incidence on RST. Experiments were then conducted to measure the traffic effect on RST increase with respect to non circulated areas. These field data were then used for comparison with forecast provided by this traffic-implemented TEB version.

  9. [Study of building quantitative analysis model for chlorophyll in winter wheat with reflective spectrum using MSC-ANN algorithm].

    Science.gov (United States)

    Liang, Xue; Ji, Hai-yan; Wang, Peng-xin; Rao, Zhen-hong; Shen, Bing-hui

    2010-01-01

    Preprocess method of multiplicative scatter correction (MSC) was used to reject noises in the original spectra produced by the environmental physical factor effectively, then the principal components of near-infrared spectroscopy were calculated by nonlinear iterative partial least squares (NIPALS) before building the back propagation artificial neural networks method (BP-ANN), and the numbers of principal components were calculated by the method of cross validation. The calculated principal components were used as the inputs of the artificial neural networks model, and the artificial neural networks model was used to find the relation between chlorophyll in winter wheat and reflective spectrum, which can predict the content of chlorophyll in winter wheat. The correlation coefficient (r) of calibration set was 0.9604, while the standard deviation (SD) and relative standard deviation (RSD) was 0.187 and 5.18% respectively. The correlation coefficient (r) of predicted set was 0.9600, and the standard deviation (SD) and relative standard deviation (RSD) was 0.145 and 4.21% respectively. It means that the MSC-ANN algorithm can reject noises in the original spectra produced by the environmental physical factor effectively and set up an exact model to predict the contents of chlorophyll in living leaves veraciously to replace the classical method and meet the needs of fast analysis of agricultural products.

  10. Short communication: Evaluation of a model for predicting Avena fatua and Descurainia sophia seed emergence in winter rapeseed

    Directory of Open Access Journals (Sweden)

    Mohammad A. Aboutalebian

    2017-07-01

    Full Text Available Avena fatua and Descurainia sophia are two important annual weeds throughout winter rapeseed (Brassica napus L. production systems in the semiarid region of Iran. Timely and more accurate control of both species may be developed if there is a better understanding of its emergence patterns. Non-linear regression techniques are usually unable to accurately predict field emergence under such environmental conditions. The objectives of this research were to evaluate the emergence patterns of A. fatua and D. sophia and determine if emergence could be predicted using cumulative soil thermal time in degree days (CTT. In the present work, cumulative seedling emergence from a winter rapeseed field during 3 years data set was fitted to cumulative soil CTT using Weibull and Gompertz functions. The Weibull model provided a better fit, based on coefficient of determination (R2sqr, root mean square of error (RMSE and Akaike index (AICd, compared to the Gompertz model between 2013 and 2016 seasons for both species. Maximum emergence of A. fatua occured 70-119 days after sowing or after equals 329-426 °Cd, while in D. sophia it occurred 119-134 days after sowing rapeseed equals 373-470 °Cd. Both models can aid in the future study of A. fatua and D. sophia emergence and assist growers and agricultural professionals with planning timely and more accurate A. fatua and D. sophia control.

  11. An analysis, sensitivity and prediction of winter fog events using FASP model over Indo-Gangetic plains, India

    Science.gov (United States)

    Srivastava, S. K., Sr.; Sharma, D. A.; Sachdeva, K.

    2017-12-01

    Indo-Gangetic plains of India experience severe fog conditions during the peak winter months of December and January every year. In this paper an attempt has been to analyze the spatial and temporal variability of winter fog over Indo-Gangetic plains. Further, an attempt has also been made to configure an efficient meso-scale numerical weather prediction model using different parameterization schemes and develop a forecasting tool for prediction of fog during winter months over Indo-Gangetic plains. The study revealed that an alarming increasing positive trend of fog frequency prevails over many locations of IGP. Hot spot and cluster analysis were conducted to identify the high fog prone zones using GIS and inferential statistical tools respectively. Hot spots on an average experiences fog on 68.27% days, it is followed by moderate and cold spots with 48.03% and 21.79% respectively. The study proposes a new FASP (Fog Analysis, sensitivity and prediction) Model for overall analysis and prediction of fog at a particular location and period over IGP. In the first phase of this model long term climatological fog data of a location is analyzed to determine its characteristics and prevailing trend using various advanced statistical techniques. During a second phase a sensitivity test is conducted with different combination of parameterization schemes to determine the most suitable combination for fog simulation over a particular location and period and in the third and final phase, first ARIMA model is used to predict the number of fog days in future . Thereafter, Numerical model is used to predict the various meteorological parameters favourable for fog forecast. Finally, Hybrid model is used for fog forecast over the study location. The results of the FASP model are validated with actual ground based fog data using statistical tools. Forecast Fog-gram generated using hybrid model during Jan 2017 shows highly encouraging results for fog occurrence/Non occurrence between

  12. Evaluation of winter temperatures on apple budbreak using grafted twigs

    Directory of Open Access Journals (Sweden)

    Fernando José Hawerroth

    2013-09-01

    Full Text Available Temperature is the main climate factor related to induction, maintenance and dormancy release in apple (Malus domestica Borkh.. The inadequate chilling exposure in apples causes budbreak problems, resulting in decrease in yield potential. Thus, the knowledge of physiological principles and environmental factors determining the dormancy phenomenon, especially winter temperature effects, it is necessary for the efficient selection of cultivars in a productive region. In addition, it is indispensable to adapt the orchard management aiming to decrease the problems caused by lack chilling during winter. The objective of this study was to evaluate the influence of different thermal conditions during the dormancy period on budbreak of apple cultivars. One-year-old twigs of 'Castel Gala' and 'Royal Gala' cultivars, grafted on M7 rootstock, were submitted to temperatures of 5, 10 and 15ºC for different exposure periods (168; 336; 672; 1,008 and 1,344 hours. After treatments execution, the plants were kept in a greenhouse at 25ºC. Budbreak was quantified when accumulated 3,444; 6,888; 10,332; 13,776; 17,220 and 20,664 GDHºC after temperature treatments. The cultivars responded differently to temperature effect during the winter period. The temperature of 15ºC during winter shows a greater effectiveness on 'Castel Gala' apple budbreak while in the 'Royal Gala' apples the temperatures of 5 and 10ºC show better performance. 'Castel Gala' cultivar (low chilling requirement may supply its physiological necessities, may be capable to budburst, even when subjected to higher temperatures in relation to 'Royal Gala' apples (high chilling requirement.

  13. Implications of climate change on winter road networks in Ontario's Far North and northern Manitoba, Canada, based on climate model projections

    Science.gov (United States)

    Hori, Y.; Cheng, V. Y. S.; Gough, W. A.

    2017-12-01

    A network of winter roads in northern Canada connects a number of remote First Nations communities to all-season roads and rails. The extent of the winter road networks depends on the geographic features, socio-economic activities, and the numbers of remote First Nations so that it differs among the provinces. The most extensive winter road networks below the 60th parallel south are located in Ontario and Manitoba, serving 32 and 18 communities respectively. In recent years, a warmer climate has resulted in a shorter winter road season and an increase in unreliable road conditions; thus, limiting access among remote communities. This study focused on examining the future freezing degree-days (FDDs) accumulations during the winter road season at selected locations throughout Ontario's Far North and northern Manitoba using recent climate model projections from the multi-model ensembles of General Circulation Models (GCMs) under the Representative Concentration Pathway (RCP) scenarios. First, the non-parametric Mann-Kendall correlation test and the Theil-Sen method were used to identify any statistically significant trends between FDDs and time for the base period (1981-2010). Second, future climate scenarios are developed for the study areas using statistical downscaling methods. This study also examined the lowest threshold of FDDs during the winter road construction in a future period. Our previous study established the lowest threshold of 380 FDDs, which derived from the relationship between the FDDs and the opening dates of James Bay Winter Road near the Hudson-James Bay coast. Thus, this study applied the threshold measure as a conservative estimate of the minimum threshold of FDDs to examine the effects of climate change on the winter road construction period.

  14. Fine-particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

    Directory of Open Access Journals (Sweden)

    S. Song

    2018-05-01

    Full Text Available pH is an important property of aerosol particles but is difficult to measure directly. Several studies have estimated the pH values for fine particles in northern China winter haze using thermodynamic models (i.e., E-AIM and ISORROPIA and ambient measurements. The reported pH values differ widely, ranging from close to 0 (highly acidic to as high as 7 (neutral. In order to understand the reason for this discrepancy, we calculated pH values using these models with different assumptions with regard to model inputs and particle phase states. We find that the large discrepancy is due primarily to differences in the model assumptions adopted in previous studies. Calculations using only aerosol-phase composition as inputs (i.e., reverse mode are sensitive to the measurement errors of ionic species, and inferred pH values exhibit a bimodal distribution, with peaks between −2 and 2 and between 7 and 10, depending on whether anions or cations are in excess. Calculations using total (gas plus aerosol phase measurements as inputs (i.e., forward mode are affected much less by these measurement errors. In future studies, the reverse mode should be avoided whereas the forward mode should be used. Forward-mode calculations in this and previous studies collectively indicate a moderately acidic condition (pH from about 4 to about 5 for fine particles in northern China winter haze, indicating further that ammonia plays an important role in determining this property. The assumed particle phase state, either stable (solid plus liquid or metastable (only liquid, does not significantly impact pH predictions. The unrealistic pH values of about 7 in a few previous studies (using the standard ISORROPIA model and stable state assumption resulted from coding errors in the model, which have been identified and fixed in this study.

  15. Simulation of Relationship between ENSO and winter precipitation over Western Himalayas: Application of Regional climate model (RegT-Band)

    Science.gov (United States)

    Tiwari, P. R.; Mohanty, U. C.; Dey, S.; Acharaya, N.; Sinha, P.

    2012-12-01

    Precipitation over the Western Himalayas region during winter is mainly associated with the passage of midlatitude synoptic systems known as western disturbances (WDs). Recently, many observational and modeling studies reported that the relationship of the Indian southwest monsoon rainfall with El Niño- Southern Oscillation (ENSO) has weakened since around 1980. But, in contrast, only very few observational studies are reported so far to examine the relationship between ENSO and the winter precipitation over the Western Himalayas region from December to February (DJF). But there is a huge gap of modeling this phenomenon. So keeping in view of the absence of modeling studies, an attempt is made to simulate the relationship between wintertime precipitations associated with large scale global forcing of ENSO over the Western Himalayas. In the present study, RegT-Band, a tropical band version of the regional climate model RegCM4 is integrated for a set of 5 El Niño (1986-87, 1991-92, 1997-98, 2002-03, 2009-10) and 4 La Niña (1984-85, 1988-89, 1999-2000, 2007-08) years with the observed sea-surface temperature and lateral boundary condition. The domain extends from 50° S to 50° N and covers the entire tropics at a grid spacing of about 45 km, i.e. it includes lateral boundary forcing only at the southern and northern boundaries. The performance evaluation of the model in capturing the large scale fields followed by ENSO response with wintertime precipitation over the Western Himalayas region has been carried out by using National Center for Environmental Prediction (NCEP)-Department of Energy (DOE) reanalysis 2 (NNRP2) data (2.5° x 2.5°) and Aphrodite precipitation data (0.25° x 0.25°). The model is able to delineate the mean circulation associated with ENSO over the region during DJF reasonably well and shows strong southwesterly to northwesterly wind flow, which is there in verification analysis also. The vertical structure of the low as well as upper level

  16. Boron nutrition and chilling tolerance of warm climate crop species.

    Science.gov (United States)

    Huang, Longbin; Ye, Zhengqian; Bell, Richard W; Dell, Bernard

    2005-10-01

    Field observations and glasshouse studies have suggested links between boron (B)-deficiency and leaf damage induced by low temperature in crop plants, but causal relationships between these two stresses at physiological, biochemical and molecular levels have yet to be explored. Limited evidence at the whole-plant level suggests that chilling temperature in the root zone restricts B uptake capacity and/or B distribution/utilization efficiency in the shoot, but the nature of this interaction depends on chilling tolerance of species concerned, the mode of low temperature treatment (abrupt versus gradual temperature decline) and growth conditions (e.g. photon flux density and relative humidity) that may exacerbate chilling stress. This review explores roles of B nutrition in chilling tolerance of continual root or transient shoot chills in crop species adapted to warm season conditions. It reviews current research on combined effects of chilling temperature (ranging from >0 to 20 degrees C) and B deficiency on growth and B nutrition responses in crop species differing in chilling tolerance. For subtropical/tropical species (e.g. cucumber, cassava, sunflower), root chilling at 10-17 degrees C decreases B uptake efficiency and B utilization in the shoot and increases the shoot : root ratio, but chilling-tolerant temperate species (e.g. oilseed rape, wheat) require much lower root chill temperatures (2-5 degrees C) to achieve the same responses. Boron deficiency exacerbates chilling injuries in leaf tissues, particularly under high photon flux density. Suggested mechanisms for B x chilling interactions in plants are: (a) chilling-induced reduction in plasmalemma hydraulic conductivity, membrane fluidity, water channel activity and root pressure, which contribute to the decrease in root hydraulic conductance, water uptake and associated B uptake; (b) chilling-induced stomatal dysfunction affecting B transport from root to shoot and B partitioning in the shoot; and (c) B

  17. Realizing User-Relevant Conceptual Model for the Ski Jump Venue of the Vancouver 2010 Winter Olympics

    Science.gov (United States)

    Teakles, Andrew; Mo, Ruping; Dierking, Carl F.; Emond, Chris; Smith, Trevor; McLennan, Neil; Joe, Paul I.

    2014-01-01

    As was the case for most other Olympic competitions, providing weather guidance for the ski jump and Nordic combined events involved its own set of unique challenges. The extent of these challenges was brought to light before the Vancouver 2010 Winter Olympics during a series of outflow wind events in the 2008/2009 winter season. The interactions with the race officials during the difficult race conditions brought on by the outflows provided a new perspective on the service delivery requirements for the upcoming Olympic Games. In particular, the turbulent nature of the winds and its impact on the ski jump practice events that season highlighted the need of race officials for nowcasting advice at very short time scales (from 2 min to 1 h) and forecast products tailored to their decision-making process. These realizations resulted in last minute modifications to the monitoring strategy leading up to the Olympic Games and required forecasters' conceptual models for flow within the Callaghan Valley to be downscaled further to reflect the evolution of turbulence at the ski jump site. The SNOW-V10 (Science of Nowcasting Olympic Weather for Vancouver 2010) team provided support for these efforts by supplying diagnostic case analyses of important events using numerical weather data and by enhancing the real-time monitoring capabilities at the ski jump venue.

  18. Assessment of winter air pollution episodes using long-range transport modeling in Hangzhou, China, during World Internet Conference, 2015.

    Science.gov (United States)

    Ni, Zhi-Zhen; Luo, Kun; Zhang, Jun-Xi; Feng, Rui; Zheng, He-Xin; Zhu, Hao-Ran; Wang, Jing-Fan; Fan, Jian-Ren; Gao, Xiang; Cen, Ke-Fa

    2018-05-01

    A winter air pollution episode was observed in Hangzhou, South China, during the Second World Internet Conference, 2015. To study the pollution characteristics and underlying causes, the Weather Research and Forecasting with Chemistry model was used to simulate the spatial and temporal evolution of the pollution episode from December 8 to 19, 2015. In addition to scenario simulations, analysis of the atmospheric trajectory and synoptic weather conditions were also performed. The results demonstrated that control measures implemented during the week preceding the conference reduced the fine particulate matter (PM 2.5 ) pollution level to some extent, with a decline in the total PM 2.5 concentration in Hangzhou of 15% (7%-25% daily). Pollutant long-range transport, which occurred due to a southward intrusion of strong cold air driven by the Siberia High, led to severe pollution in Hangzhou on December 15, 2015, accounting for 85% of the PM 2.5 concentration. This study provides new insights into the challenge of winter pollution prevention in Hangzhou. For adequate pollution prevention, more regional collaborations should be fostered when creating policies for northern China. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Eurasian Winter Storm Activity at the End of the Century: A CMIP5 Multi-model Ensemble Projection

    Science.gov (United States)

    Basu, Soumik; Zhang, Xiangdong; Wang, Zhaomin

    2018-01-01

    Extratropical cyclone activity over Eurasia has exhibited a weakening trend in the recent decade. Extratropical cyclones bring precipitation and hence supply fresh water for winter crops in the mid- and high-latitude regions of Eurasia. Any changes in extratropical cyclone activity over Eurasia in the future may have a critical impact on winter agriculture and the economies of affected communities. However, potential future changes in regional storm activity over Eurasia have not been studied in detail. Therefore, in this study, we investigate anticipated changes in extratropical storm activity by the end of the century through a detailed examination of the historical and future emission scenarios from six different models from CMIP5. A statistical analysis of different parameters of storm activity using a storm identification and tracking algorithm reveals a decrease in the number of storms over mid-latitude regions. However, intense storms with longer duration are projected over high latitude Eurasia. A further examination of the physical mechanism for these changes reveals that a decrease in the meridional temperature gradient and a weakening of the vertical wind shear over the mid-latitudes are responsible for these changes in storm activity.

  20. Human perception of indoor environment generated by chilled ceiling combined with mixing ventilation or localised chilled beam under cooling mode

    DEFF Research Database (Denmark)

    Bolashikov, Zhecho Dimitrov; Nygaard, Linette; Uth, Simon C.

    2014-01-01

    Experiments with 24 subjects were performed to study and compare the human perception of the indoor environment under summer conditions generated by a chilled ceiling combined with overhead mixing ventilation and localised chilled beam. The experiments were performed in an experimental chamber (4....../s and 16 0C. The localised chilled beam was installed over the workstation placed by the simulated window. During the experiment the subjects were delegated control over the primary flow rate supplied by the localised chilled beam. The whole exposure lasted 2 hours with 30 min of acclimatisation before...

  1. Internal development of vegetative buds of Norway spruce trees in relation to accumulated chilling and forcing temperatures.

    Science.gov (United States)

    Viherä-Aarnio, Anneli; Sutinen, Sirkka; Partanen, Jouni; Häkkinen, Risto

    2014-05-01

    The timing of budburst of temperate trees is known to be controlled by complicated interactions of temperature and photoperiod. To improve the phenological models of budburst, better knowledge of the internal bud development preceding budburst in relation to environmental cues is needed. We studied the effect of accumulated chilling and forcing temperatures on the internal development of vegetative buds preceding budburst in Norway spruce [Picea abies (L.) Karst.]. Branches from 17-year-old trees of southern Finnish origin were transferred eight times at 1- to 2-week intervals from October to December 2007 from the field at Punkaharju (61°48'N, 29°20'E) to the greenhouse with forcing conditions (day length 12 h, +20 °C). After seven different durations of forcing, the developmental phase and primordial shoot growth of the buds were analysed at the stereomicroscopic level. Air temperature was recorded hourly throughout the study period. The accumulated chilling unit sum had a significant effect on the temperature sum that was required to attain a certain developmental phase; a higher amount of chilling required a lower amount of forcing. The variation in the rate of development of different buds within each sample branch in relation to the chilling unit and forcing temperature sum was low. Regarding primordial shoot growth, there was also an inverse relation between accumulated chilling and forcing, i.e., a higher accumulated chilling unit sum before forcing required a lower temperature sum to initiate primordial shoot growth and resulted in a stronger effect of accumulated forcing. A second-order regression model with an interaction of chilling and forcing explained the variation of primordial shoot growth with high precision (R(2) = 0.88). However, further studies are required to determine the final parameter values to be used in phenological modelling. © The Author 2014. Published by Oxford University Press. All rights reserved.

  2. Avaliação da necessidade de frio em pessegueiro Avaliation of chilling requirement in peach

    Directory of Open Access Journals (Sweden)

    Idemir Citadin

    2002-12-01

    Full Text Available A necessidade de frio de seis cultivares de pessegueiro [Prunus persica (L. Batsch] foi estudada em plantas de um e dois anos, em vasos, submetidas a 150; 300; 450 e 600 horas a 2ºC, e em ramos coletados periodicamente em plantas sob condições de frio natural, a campo. Considerando os resultados obtidos nos dois experimentos, estima-se que a necessidade de frio de 'Precocinho' é em torno de 300 horas a 2ºC, equivalente a 150 unidades de frio (UF pelo modelo de Utah, ou próxima a 200 horas abaixo de 12ºC; para 'Eldorado' e 'Rio grandense', em 450 horas a 2ºC (225 UF ou 365 horas abaixo de 12ºC; para 'BR-1', em 450 horas a 2ºC (225 UF ou 418 horas abaixo de 12ºC; e para 'Planalto' e 'Della Nona', acima de 600 horas a 2ºC (>300 UF. Não foi possível estabelecer a necessidade de frio abaixo de 12ºC para 'Della Nona'.Chilling requirement was investigated in six peach [Prunus persica (L. Batsch] cultivars observing plants in containers, with one or two years, artificially chilled by 150, 300, 450, and 600 hours at 2ºC, and in excised shoots that were periodically taken from the orchard during the rest period. Chilling requirement of 'Precocinho' is 300 hours at 2ºC (around 150 chilling units - CU - using Utah Model or around 200 hours under 12ºC; 'Riograndense' and 'Eldorado' have 450 chilling hours at 2ºC (225 CU or 365 chilling hours under 12ºC; 'BR-1' is 450 chilling requirement at 2ºC (225 CU or 418 chilling hours under 12 ºC; and 'Planalto' and 'Della Nona' are over 600 chilling hours at 2ºC (>300 CU. It was not possible to estimate chilling requirement in 'Della Nona' using temperatures under 12 ºC.

  3. Winter wheat yield estimation of remote sensing research based on WOFOST crop model and leaf area index assimilation

    Science.gov (United States)

    Chen, Yanling; Gong, Adu; Li, Jing; Wang, Jingmei

    2017-04-01

    Accurate crop growth monitoring and yield predictive information are significant to improve the sustainable development of agriculture and ensure the security of national food. Remote sensing observation and crop growth simulation models are two new technologies, which have highly potential applications in crop growth monitoring and yield forecasting in recent years. However, both of them have limitations in mechanism or regional application respectively. Remote sensing information can not reveal crop growth and development, inner mechanism of yield formation and the affection of environmental meteorological conditions. Crop growth simulation models have difficulties in obtaining data and parameterization from single-point to regional application. In order to make good use of the advantages of these two technologies, the coupling technique of remote sensing information and crop growth simulation models has been studied. Filtering and optimizing model parameters are key to yield estimation by remote sensing and crop model based on regional crop assimilation. Winter wheat of GaoCheng was selected as the experiment object in this paper. And then the essential data was collected, such as biochemical data and farmland environmental data and meteorological data about several critical growing periods. Meanwhile, the image of environmental mitigation small satellite HJ-CCD was obtained. In this paper, research work and major conclusions are as follows. (1) Seven vegetation indexes were selected to retrieve LAI, and then linear regression model was built up between each of these indexes and the measured LAI. The result shows that the accuracy of EVI model was the highest (R2=0.964 at anthesis stage and R2=0.920 at filling stage). Thus, EVI as the most optimal vegetation index to predict LAI in this paper. (2) EFAST method was adopted in this paper to conduct the sensitive analysis to the 26 initial parameters of the WOFOST model and then a sensitivity index was constructed

  4. Incidence of chilling injury in fresh-cut 'Kent' mangoes

    Science.gov (United States)

    The preferred storage temperature for fresh-cut fruits in terms of visual quality retention is around 5 °C, which is considered to be a chilling temperature for chilling sensitive tropical fruits like mango (Mangifera indica L.). Changes in visual and compositional quality factors, aroma volatile pr...

  5. Differential responses of two rubber tree clones to chilling stress ...

    African Journals Online (AJOL)

    Chilling stress is one of the most important environmental factors that limit the growth, distribution and yield of rubber tree in China. The effects of chilling stress on the grated plants of two rubber trees clones, GT1 and Wenchang217, were studied by physiological methods in controlled light chamber in order to explore the ...

  6. Early Season Large-Area Winter Crop Mapping Using MODIS NDVI Data, Growing Degree Days Information and a Gaussian Mixture Model

    Science.gov (United States)

    Skakun, Sergii; Franch, Belen; Vermote, Eric; Roger, Jean-Claude; Becker-Reshef, Inbal; Justice, Christopher; Kussul, Nataliia

    2017-01-01

    Knowledge on geographical location and distribution of crops at global, national and regional scales is an extremely valuable source of information applications. Traditional approaches to crop mapping using remote sensing data rely heavily on reference or ground truth data in order to train/calibrate classification models. As a rule, such models are only applicable to a single vegetation season and should be recalibrated to be applicable for other seasons. This paper addresses the problem of early season large-area winter crop mapping using Moderate Resolution Imaging Spectroradiometer (MODIS) derived Normalized Difference Vegetation Index (NDVI) time-series and growing degree days (GDD) information derived from the Modern-Era Retrospective analysis for Research and Applications (MERRA-2) product. The model is based on the assumption that winter crops have developed biomass during early spring while other crops (spring and summer) have no biomass. As winter crop development is temporally and spatially non-uniform due to the presence of different agro-climatic zones, we use GDD to account for such discrepancies. A Gaussian mixture model (GMM) is applied to discriminate winter crops from other crops (spring and summer). The proposed method has the following advantages: low input data requirements, robustness, applicability to global scale application and can provide winter crop maps 1.5-2 months before harvest. The model is applied to two study regions, the State of Kansas in the US and Ukraine, and for multiple seasons (2001-2014). Validation using the US Department of Agriculture (USDA) Crop Data Layer (CDL) for Kansas and ground measurements for Ukraine shows that accuracies of greater than 90% can be achieved in mapping winter crops 1.5-2 months before harvest. Results also show good correspondence to official statistics with average coefficients of determination R(exp. 2) greater than 0.85.

  7. Simulation of biomass yield of regular and chilling tolerant Miscanthus cultivars and reed canary grass in different climates of Europe

    DEFF Research Database (Denmark)

    Kandel, Tanka Prasad; Hastings, Astley; Jørgensen, Uffe

    2016-01-01

    Miscanthus and reed canary grass (RCG) are C4 and C3 perennial grasses which are popular in Europe as energy crops. Although Miscanthus is relatively chilling tolerant compared to other C4 species, its production in northern Europe is still constrained by cold temperature. A more chilling tolerant...... Miscanthus cultivar which can emerge early in the spring would utilize more solar radiation and produce higher biomass yields. In this study, using MiscanFor model, we estimated potential biomass yield of Miscanthus in current and future climates with the assumption that breeding would provide a chilling...

  8. Effects of chilling on protein synthesis in tomato suspension cultures

    International Nuclear Information System (INIS)

    Matadial, B.; Pauls, K.P.

    1989-01-01

    The effect of chilling on cell growth, cell viability, protein content and protein composition in suspension cultures of L. esculentum and L. hirsutum was investigated. Cell growth for both species was arrested at 2 degrees C but when cultures were transferred to 25 degree C cell growth resumed. There was no difference in viability between control and chilled cultures of L. esculentum, however, L. hirsutum control cultures exhibited larger amounts of Fluorescein Diacetate induced fluorescence than chilled cultures. 35 S-methionine incorporation into proteins was 2.5-2 times higher in L. hirsutum than in L. esculentum. Quantitative and qualitative differences, in 35 S-methionine labelled proteins, between chilled and control cultures were observed by SDS-PAGE and fluorography. Protein content in chilled cultures decreased over time but then increased when cultures were transferred to 25 degrees C

  9. WINTER SAECULUM

    Directory of Open Access Journals (Sweden)

    Emil Mihalina

    2017-03-01

    Full Text Available Accumulated imbalances in the economy and on the markets cause specific financial market dynamics that have formed characteristic patterns kept throughout long financial history. In 2008 Authors presented their expectations of key macroeconomic and selected asset class markets developments for period ahead based on Saeculum theory. Use of term Secular describes a specific valuation environment during prolonged period. If valuations as well as selected macro variables are considered as a tool for understanding business cycles then market cycles become much more obvious and easily understandable. Therefore over the long run, certain asset classes do better in terms of risk reward profile than others. Further on, there is no need for frequent portfolio rebalancing and timing of specific investment positions within a particular asset class market. Current stage in cycle development suggests a need for reassessment of trends and prevailing phenomena due to cyclical nture of long lasting Saeculums. Paper reviews developments in recognizable patterns of selected metrics in current Winter Saeculum dominated with prevailing forces of delivering, deflation and decrease in velocity of money.

  10. Balance sheet method assessment for nitrogen fertilization in winter wheat: II. alternative strategies using the CropSyst simulation model

    Directory of Open Access Journals (Sweden)

    Maria Corbellini

    2006-09-01

    Full Text Available It is important, both for farmer profit and for the environment, to correctly dose fertilizer nitrogen (N for winter wheat growth. Balance-sheet methods are often used to calculate the recommended dose of N fertilizer. Other methods are based on the dynamic simulation of cropping systems. Aim of the work was to evaluate the balance-sheet method set up by the Region Emilia-Romagna (DPI, by comparing it with the cropping systems simulation model CropSyst (CS, and with an approach based on fixed supplies of N (T. A 3-year trial was structured as a series of N fertility regimes at 3 sites (Papiano di Marsciano, Ravenna, San Pancrazio. The N-regimes were generated at each site-year as separate trials in which 3 N rates were applied: N1 (DPI, N2 (DPI+50 kg ha-1 N at spike initiation, N3 (DPI + 50 kg ha-1 N at early booting. Above ground biomass and soil data (NO3-N and water were sampled and used to calibrate CS. Doses of fertilizer N were calculated by both DPI and CS for winter wheat included in three typical rotations for Central and Northern Italy. Both these methods and method T were simulated at each site over 50 years, by using daily generated weather data. The long-term simulation allowed evaluating such alternative fertilization strategies. DPI and CS estimated comparable crop yields and N leached amounts, and both resulted better than T. Minor risk of leaching emerged for all N doses. The N2 and N3 rates allowed slightly higher crop yields than N1.

  11. A winter distribution model for Bicknell's Thrush (Catharus bicknelli), a conservation tool for a threatened migratory songbird

    Science.gov (United States)

    K. P. McFarland; C. C. Rimmer; J. E. Goetz; Y. Aubry; J. M. Wunderle Jr.; A. Hayes-Sutton; J. M. Townsend; A. Llanes Sosa; A. Kirkconnell

    2013-01-01

    Conservation planning and implementation require identifying pertinent habitats and locations where protection and management may improve viability of targeted species. The winter range of Bicknell’s Thrush (Catharus bicknelli), a threatened Nearctic-Neotropical migratory songbird, is restricted to the Greater Antilles. We analyzed winter records from the mid-1970s to...

  12. Comparisons of patch-use models for wintering American tree sparrows

    Science.gov (United States)

    Tome, M.W.

    1990-01-01

    Optimal foraging theory has stimulated numerous theoretical and empirical studies of foraging behavior for >20 years. These models provide a valuable tool for studying the foraging behavior of an organism. As with any other tool, the models are most effective when properly used. For example, to obtain a robust test of a foraging model, Stephens and Krebs (1986) recommend experimental designs in which four questions are answered in the affirmative. First, do the foragers play the same "game" as the model? Sec- ond, are the assumptions of the model met? Third, does the test rule out alternative possibilities? Finally, are the appropriate variables measured? Negative an- swers to any of these questions could invalidate the model and lead to confusion over the usefulness of foraging theory in conducting ecological studies. Gaines (1989) attempted to determine whether American Tree Sparrows (Spizella arborea) foraged by a time (Krebs 1973) or number expectation rule (Gibb 1962), or in a manner consistent with the predictions of Charnov's (1976) marginal value theorem (MVT). Gaines (1989: 118) noted appropriately that field tests of foraging models frequently involve uncontrollable circumstances; thus, it is often difficult to meet the assumptions of the models. Gaines also states (1989: 118) that "violations of the assumptions are also in- formative but do not constitute robust tests of predicted hypotheses," and that "the problem can be avoided by experimental analyses which concurrently test mutually exclusive hypotheses so that alter- native predictions will be eliminated if falsified." There is a problem with this approach because, when major assumptions of models are not satisfied, it is not justifiable to compare a predator's foraging behavior with the model's predictions. I submit that failing to follow the advice offered by Stephens and Krebs (1986) can invalidate tests of foraging models.

  13. Effect of modification melt treatment on casting/chill interfacial heat transfer and electrical conductivity of Al-13% Si alloy

    International Nuclear Information System (INIS)

    Narayan Prabhu, K.; Ravishankar, B.N.

    2003-01-01

    For successful modelling of the solidification process, a reliable heat transfer boundary condition data is required. These boundary conditions are significantly influenced by the casting and mould parameters. In the present work, the effect of sodium modification melt treatment on casting/chill interfacial heat transfer during upward solidification of an Al-13% Si alloy against metallic chills is investigated using thermal analysis and inverse modelling techniques. In the presence of chills, modification melt treatment resulted in an increase in the cooling rate of the solidifying casting near the casting/chill interfacial region. The corresponding interfacial heat flux transients and electrical conductivities are also found to be higher. This is attributed to (i) improvement in the casting/chill interfacial thermal contact condition brought about by the decrease in the surface tension of the liquid metal on addition of sodium and (ii) increase in the electronic heat conduction in the initial solidified shell due to change in the morphology of silicon from a acicular type to a fine fibrous structure and increase in the ratio of the modification rating to the secondary dendrite arm spacing

  14. Evaluation of air-soil temperature relationships simulated by land surface models during winter across the permafrost region

    Science.gov (United States)

    Wang, Wenli; Rinke, Annette; Moore, John C.; Ji, Duoying; Cui, Xuefeng; Peng, Shushi; Lawrence, David M.; McGuire, A. David; Burke, Eleanor J.; Chen, Xiaodong; Delire, Christine; Koven, Charles; MacDougall, Andrew; Saito, Kazuyuki; Zhang, Wenxin; Alkama, Ramdane; Bohn, Theodore J.; Ciais, Philippe; Decharme, Bertrand; Gouttevin, Isabelle; Hajima, Tomohiro; Krinner, Gerhard; Lettenmaier, Dennis P.; Miller, Paul A.; Smith, Benjamin; Sueyoshi, Tetsuo

    2016-01-01

     A realistic simulation of snow cover and its thermal properties are important for accurate modelling of permafrost. We analyze simulated relationships between air and near-surface (20 cm) soil temperatures in the Northern Hemisphere permafrost region during winter, with a particular focus on snow insulation effects in nine land surface models and compare them with observations from 268 Russian stations. There are large across-model differences as expressed by simulated differences between near-surface soil and air temperatures, (ΔT), of 3 to 14 K, in the gradients between soil and air temperatures (0.13 to 0.96°C/°C), and in the relationship between ΔT and snow depth. The observed relationship between ΔT and snow depth can be used as a metric to evaluate the effects of each model's representation of snow insulation, and hence guide improvements to the model’s conceptual structure and process parameterizations. Models with better performance apply multi-layer snow schemes and consider complex snow processes. Some models show poor performance in representing snow insulation due to underestimation of snow depth and/or overestimation of snow conductivity. Generally, models identified as most acceptable with respect to snow insulation simulate reasonable areas of near-surface permafrost (12–16 million km2). However, there is not a simple relationship between the quality of the snow insulation in the acceptable models and the simulated area of Northern Hemisphere near-surface permafrost, likely because several other factors such as differences in the treatment of soil organic matter, soil hydrology, surface energy calculations, and vegetation also provide important controls on simulated permafrost distribution.

  15. Fronts and precipitation in CMIP5 models for the austral winter of the Southern Hemisphere

    Science.gov (United States)

    Blázquez, Josefina; Solman, Silvina A.

    2018-04-01

    Wintertime fronts climatology and the relationship between fronts and precipitation as depicted by a group of CMIP5 models are evaluated over the Southern Hemisphere (SH). The frontal activity is represented by an index that takes into account the vorticity, the gradient of temperature and the specific humidity at the 850 hPa level. ERA-Interim reanalysis and GPCP datasets are used to assess the performance of the models in the present climate. Overall, it is found that the models can reproduce adequately the main features of frontal activity and front frequency over the SH. The total precipitation is overestimated in most of the models, especially the maximum values over the mid latitudes. This overestimation could be related to the high values of precipitation frequency that are identified in some of the models evaluated. The relationship between fronts and precipitation has also been evaluated in terms of both frequency of frontal precipitation and percentage of precipitation due to fronts. In general terms, the models overestimate the proportion between frontal and total precipitation. In contrast with frequency of total precipitation, the frequency of frontal precipitation is well reproduced by the models, with the higher values located at the mid latitudes. The results suggest that models represent very well the dynamic forcing (fronts) and the frequency of frontal precipitation, though the amount of precipitation due to fronts is overestimated.

  16. Winter-to-Summer Precipitation Phasing in Southwestern North America: A Multi-Century Perspective from Paleoclimatic Model-Data Comparisons

    Science.gov (United States)

    Coats, Sloan; Smerdon, Jason E.; Seager, Richard; Griffin, Daniel; Cook, Benjamin I.

    2015-01-01

    The phasing of winter-to-summer precipitation anomalies in the North American monsoon (NAM) region 2 (113.25 deg W-107.75 deg W, 30 deg N-35.25 deg N-NAM2) of southwestern North America is analyzed in fully coupled simulations of the Last Millennium and compared to tree ring reconstructed winter and summer precipitation variability. The models simulate periods with in-phase seasonal precipitation anomalies, but the strength of this relationship is variable on multidecadal time scales, behavior that is also exhibited by the reconstructions. The models, however, are unable to simulate periods with consistently out-of-phase winter-to-summer precipitation anomalies as observed in the latter part of the instrumental interval. The periods with predominantly in-phase winter-to-summer precipitation anomalies in the models are significant against randomness, and while this result is suggestive of a potential for dual-season drought on interannual and longer time scales, models do not consistently exhibit the persistent dual-season drought seen in the dendroclimatic reconstructions. These collective findings indicate that model-derived drought risk assessments may underestimate the potential for dual-season drought in 21st century projections of hydroclimate in the American Southwest and parts of Mexico.

  17. Assessing Uncertainties of Water Footprints Using an Ensemble of Crop Growth Models on Winter Wheat

    Directory of Open Access Journals (Sweden)

    Kurt Christian Kersebaum

    2016-12-01

    Full Text Available Crop productivity and water consumption form the basis to calculate the water footprint (WF of a specific crop. Under current climate conditions, calculated evapotranspiration is related to observed crop yields to calculate WF. The assessment of WF under future climate conditions requires the simulation of crop yields adding further uncertainty. To assess the uncertainty of model based assessments of WF, an ensemble of crop models was applied to data from five field experiments across Europe. Only limited data were provided for a rough calibration, which corresponds to a typical situation for regional assessments, where data availability is limited. Up to eight models were applied for wheat. The coefficient of variation for the simulated actual evapotranspiration between models was in the range of 13%–19%, which was higher than the inter-annual variability. Simulated yields showed a higher variability between models in the range of 17%–39%. Models responded differently to elevated CO2 in a FACE (Free-Air Carbon Dioxide Enrichment experiment, especially regarding the reduction of water consumption. The variability of calculated WF between models was in the range of 15%–49%. Yield predictions contributed more to this variance than the estimation of water consumption. Transpiration accounts on average for 51%–68% of the total actual evapotranspiration.

  18. Evaluation of the Community Multiscale Air Quality Model for Simulating Winter Ozone Formation in the Uinta Basin

    Science.gov (United States)

    Matichuk, Rebecca; Tonnesen, Gail; Luecken, Deborah; Gilliam, Rob; Napelenok, Sergey L.; Baker, Kirk R.; Schwede, Donna; Murphy, Ben; Helmig, Detlev; Lyman, Seth N.; Roselle, Shawn

    2017-12-01

    The Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ) models were used to simulate a 10 day high-ozone episode observed during the 2013 Uinta Basin Winter Ozone Study (UBWOS). The baseline model had a large negative bias when compared to ozone (O3) and volatile organic compound (VOC) measurements across the basin. Contrary to other wintertime Uinta Basin studies, predicted nitrogen oxides (NOx) were typically low compared to measurements. Increases to oil and gas VOC emissions resulted in O3 predictions closer to observations, and nighttime O3 improved when reducing the deposition velocity for all chemical species. Vertical structures of these pollutants were similar to observations on multiple days. However, the predicted surface layer VOC mixing ratios were generally found to be underestimated during the day and overestimated at night. While temperature profiles compared well to observations, WRF was found to have a warm temperature bias and too low nighttime mixing heights. Analyses of more realistic snow heat capacity in WRF to account for the warm bias and vertical mixing resulted in improved temperature profiles, although the improved temperature profiles seldom resulted in improved O3 profiles. While additional work is needed to investigate meteorological impacts, results suggest that the uncertainty in the oil and gas emissions contributes more to the underestimation of O3. Further, model adjustments based on a single site may not be suitable across all sites within the basin.

  19. Modelling of air quality for Winter and Summer episodes in Switzerland. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Andreani-Aksoyoglu, S.; Keller, J.; Barmpadimos, L.; Oderbolz, D.; Tinguely, M.; Prevot, A. [Paul Scherrer Institute (PSI), Laboratory of Atmospheric Chemistry, Villigen (Switzerland); Alfarra, R. [University of Manchester, Manchester (United Kingdom); Sandradewi, J. [Jisca Sandradewi, Hoexter (Germany)

    2009-05-15

    This final report issued by the General Energy Research Department and its Laboratory of Atmospheric Chemistry at the Paul Scherrer Institute (PSI) reports on the results obtained from the modelling of regional air quality for three episodes, January-February 2006, June 2006 and January 2007. The focus of the calculations is on particulate matter concentrations, as well as on ozone levels in summer. The model results were compared with the aerosol data collected by an Aerosol Mass Spectrometer (AMS), which was operated during all three episodes as well as with the air quality monitoring data from further monitoring programs. The air quality model used in this study is described and the results obtained for various types of locations - rural, city, high-altitude and motorway-near - are presented and discussed. The models used are described.

  20. Coupled climate model simulations of Mediterranean winter cyclones and large-scale flow patterns

    Directory of Open Access Journals (Sweden)

    B. Ziv

    2013-03-01

    Full Text Available The study aims to evaluate the ability of global, coupled climate models to reproduce the synoptic regime of the Mediterranean Basin. The output of simulations of the 9 models included in the IPCC CMIP3 effort is compared to the NCEP-NCAR reanalyzed data for the period 1961–1990. The study examined the spatial distribution of cyclone occurrence, the mean Mediterranean upper- and lower-level troughs, the inter-annual variation and trend in the occurrence of the Mediterranean cyclones, and the main large-scale circulation patterns, represented by rotated EOFs of 500 hPa and sea level pressure. The models reproduce successfully the two maxima in cyclone density in the Mediterranean and their locations, the location of the average upper- and lower-level troughs, the relative inter-annual variation in cyclone occurrences and the structure of the four leading large scale EOFs. The main discrepancy is the models' underestimation of the cyclone density in the Mediterranean, especially in its western part. The models' skill in reproducing the cyclone distribution is found correlated with their spatial resolution, especially in the vertical. The current improvement in model spatial resolution suggests that their ability to reproduce the Mediterranean cyclones would be improved as well.

  1. Modeling a typical winter-time dust event over the Arabian Peninsula and the Red Sea

    KAUST Repository

    Kalenderski, Stoitchko; Stenchikov, Georgiy L.; Zhao, C.

    2013-01-01

    2009. The model predicted that the total amount of emitted dust was 18.3 Tg for the entire dust outburst period and that the two maximum daily rates were ?2.4 Tg day-1 and ?1.5 Tg day-1, corresponding to two periods with the highest aerosol optical

  2. Assessing uncertainties of water footprints using an ensemble of crop growth models on winter wheat

    Czech Academy of Sciences Publication Activity Database

    Kersebaum, K. C.; Kroes, J.; Gobin, A.; Takáč, J.; Hlavinka, Petr; Trnka, Miroslav; Ventrella, D.; Giglio, L.; Ferrise, R.; Moriondo, M.; Marta, A. D.; Luo, Q.; Eitzinger, Josef; Mirschel, W.; Weigel, H-J.; Manderscheid, R.; Hofmann, M.; Nejedlík, P.; Hösch, J.

    2016-01-01

    Roč. 8, č. 12 (2016), č. článku 571. ISSN 2073-4441 R&D Projects: GA MŠk(CZ) LO1415; GA MŠk(CZ) LD13030 Institutional support: RVO:67179843 Keywords : water footprint * uncertainty * model ensemble * wheat Subject RIV: DA - Hydrology ; Limnology Impact factor: 1.832, year: 2016

  3. Numerical model simulations of boundary-layer dynamics during winter conditions

    DEFF Research Database (Denmark)

    Melas, D.; Persson, T.; Bruin, H. de

    2001-01-01

    A mesoscale numerical model, incorporating a land-surface scheme based on Deardorffs' approach, is used to study the diurnal variation of the boundary layer structure and surface fluxes during four consecutive days with air temperatures well below zero, snow covered ground and changing synoptic f...

  4. The isotopic composition of precipitation from a winter storm – a case study with the limited-area model COSMOiso

    Directory of Open Access Journals (Sweden)

    K. Yoshimura

    2012-02-01

    Full Text Available Stable water isotopes are valuable tracers of the atmospheric water cycle, and potentially provide useful information also on weather-related processes. In order to further explore this potential, the water isotopes H218O and HDO are incorporated into the limited-area model COSMO. In a first case study, the new COSMOiso model is used for simulating a winter storm event in January 1986 over the eastern United States associated with intense frontal precipitation. The modelled isotope ratios in precipitation and water vapour are compared to spatially distributed δ18O observations. COSMOiso very accurately reproduces the statistical distribution of δ18O in precipitation, and also the synoptic-scale spatial pattern and temporal evolution agree well with the measurements. Perpendicular to the front that triggers most of the rainfall during the event, the model simulates a gradient in the isotopic composition of the precipitation, with high δ18O values in the warm air and lower values in the cold sector behind the front. This spatial pattern is created through an interplay of large scale air mass advection, removal of heavy isotopes by precipitation at the front and microphysical interactions between rain drops and water vapour beneath the cloud base. This investigation illustrates the usefulness of high resolution, event-based model simulations for understanding the complex processes that cause synoptic-scale variability of the isotopic composition of atmospheric waters. In future research, this will be particularly beneficial in combination with laser spectrometric isotope observations with high temporal resolution.

  5. Modeling the winter-to-summer transition of prokaryotic and viral abundance in the Arctic Ocean.

    Science.gov (United States)

    Winter, Christian; Payet, Jérôme P; Suttle, Curtis A

    2012-01-01

    One of the challenges in oceanography is to understand the influence of environmental factors on the abundances of prokaryotes and viruses. Generally, conventional statistical methods resolve trends well, but more complex relationships are difficult to explore. In such cases, Artificial Neural Networks (ANNs) offer an alternative way for data analysis. Here, we developed ANN-based models of prokaryotic and viral abundances in the Arctic Ocean. The models were used to identify the best predictors for prokaryotic and viral abundances including cytometrically-distinguishable populations of prokaryotes (high and low nucleic acid cells) and viruses (high- and low-fluorescent viruses) among salinity, temperature, depth, day length, and the concentration of Chlorophyll-a. The best performing ANNs to model the abundances of high and low nucleic acid cells used temperature and Chl-a as input parameters, while the abundances of high- and low-fluorescent viruses used depth, Chl-a, and day length as input parameters. Decreasing viral abundance with increasing depth and decreasing system productivity was captured well by the ANNs. Despite identifying the same predictors for the two populations of prokaryotes and viruses, respectively, the structure of the best performing ANNs differed between high and low nucleic acid cells and between high- and low-fluorescent viruses. Also, the two prokaryotic and viral groups responded differently to changes in the predictor parameters; hence, the cytometric distinction between these populations is ecologically relevant. The models imply that temperature is the main factor explaining most of the variation in the abundances of high nucleic acid cells and total prokaryotes and that the mechanisms governing the reaction to changes in the environment are distinctly different among the prokaryotic and viral populations.

  6. Smoke inputs to climate models: optical properties and height distribution for nuclear winter studies

    International Nuclear Information System (INIS)

    Penner, J.E.; Haselman, L.C. Jr.

    1985-04-01

    Smoke from fires produced in the aftermath of a major nuclear exchange has been predicted to cause large decreases in land surface temperatures. The extent of the decrease and even the sign of the temperature change depend on the optical characteristics of the smoke and how it is distributed with altitude. The height distribution of smoke over a fire is determined by the amount of buoyant energy produced by the fire and the amount of energy released by the latent heat of condensation of water vapor. The optical properties of the smoke depend on the size distribution of smoke particles which changes due to coagulation within the lofted plume. We present calculations demonstrating these processes and estimate their importance for the smoke source term input for climate models. For high initial smoke densities and for absorbing smoke ( m = 1.75 - 0.3i), coagulation of smoke particles within the smoke plume is predicted to first increase, then decrease, the size-integrated extinction cross section. However, at the smoke densities predicted in our model (assuming a 3% emission rate for smoke) and for our assumed initial size distribution, the attachment rates for brownian and turbulent collision processes are not fast enough to alter the smoke size distribution enough to significantly change the integrated extinction cross section. Early-time coagulation is, however, fast enough to allow further coagulation, on longer time scales, to act to decrease the extinction cross section. On these longer time scales appropriate to climate models, coagulation can decrease the extinction cross section by almost a factor of two before the smoke becomes well mixed around the globe. This process has been neglected in past climate effect evaluations, but could have a significant effect, since the extinction cross section enters as an exponential factor in calculating the light attenuation due to smoke. 10 refs., 20 figs

  7. Factors limiting the grain protein content of organic winter wheat in south-eastern France: a mixed-model approach

    NARCIS (Netherlands)

    Casagrande, M.; David, C.; Valantin-Morison, M.; Makowski, D.; Jeuffroy, M.H.

    2009-01-01

    Organic agriculture could achieve the objectives of sustainable agriculture by banning the use of synthetic fertilizers and pesticides. However, organic crops generally show lower performances than conventional ones. In France, organic winter wheat production is characterized by low grain protein

  8. Modeling the Habitat of the Red-Crowned Crane (Grus japonensis Wintering in Cheorwon-Gun to Support Decision Making

    Directory of Open Access Journals (Sweden)

    Ho Gul Kim

    2016-06-01

    Full Text Available Cheorwon-gun is an important wintering area for the red-crowned crane (Grus japonensis. Although eco-tourism has been recently proposed as a means to stimulate the local economy, it may have adverse effects on the crane. We believe a science-based conservation plan is needed to mitigate these negative effects. To this end, our study had three objectives: (1 to analyze the red-crowned crane habitat and its suitability in Cheorwon-gun, using field surveys and habitat modeling; (2 to check the feasibility of alternative habitat patches across demilitarized zones (DMZs; and (3 to propose a conceptual diagram that minimizes habitat loss during development activities. We aim to quantify habitat suitability, the farmland area needed to support existing crane populations in wintertime, disturbance caused by human activities, and vehicular spatial patterns. These data could be used in spatial planning. The framework of this study and the process of making a conceptual diagram could be applied to other areas where there is a conflict between development and habitat conservation.

  9. Ecosystem function and service quantification and valuation in a conventional winter wheat production system with DAISY model in Denmark

    DEFF Research Database (Denmark)

    Ghaley, Bhim Bahadur; Porter, John Roy

    2014-01-01

    and ES provision. The objective was to quantify two EF: soil water storage and nitrogen mineralization and three ES: food and fodder production and carbon sequestration, in a conventional winter wheat production system at 2.6% SOM compared to 50% lower (1.3%) and 50% higher (3.9%) SOM in Denmark by DAISY...... model. At 2.6% SOM, the food and fodder production was 6.49 and 6.86tha-1year-1 respectively whereas carbon sequestration and soil water storage was 9.73tha-1year-1 and 684mmha-1year-1 respectively and nitrogen mineralisation was 83.58kgha-1year-1. At 2.6% SOM, the two EF and three ES values were US......$ 177 and US$ 2542ha-1year-1 respectively equivalent to US$ 96 and US$1370 millionyear-1 respectively in Denmark. The EF and ES quantities and values were positively correlated with SOM content. Hence, the quantification and valuation of EF and ES provides an empirical tool for optimising the EF and ES...

  10. Comparison of mesoscale model and tower measurements of surface fluxes during Winter Icing and Storms Program/Atmospheric Radiation Measurement 91

    International Nuclear Information System (INIS)

    Oncley, S.P.; Dudhia, J.

    1994-01-01

    This study is an evaluation of the ability of the Pennsylvania State University/National Center for Atmospheric Research (NCAR) mesoscale model (MM4) to determine surface fluxes to see if measured fluxes should be assimilated into model runs. Fluxes were compared from a high-resolution (5 km grid spacing) MM4 run during one day of the Winter Icing and Storms Programs/Atmospheric Radiation Measurement (WISP/ARM) experiment (over NE Colorado in winter 1991) with direct flux measurements made from a tower over a representative site by a three-dimensional sonic anemometer and fast response temperature and humidity sensors. This tower was part of the NCAR Atmosphere-Surface Turbulent Exchange Research (ASTER) facility. Also, mean values were compared to check whether any differences were due to the model parameterization or model variables

  11. Vernalization and the Chilling Requirement to Exit Bud Dormancy: Shared or Separate Regulation?

    Directory of Open Access Journals (Sweden)

    Amy M Brunner

    2014-12-01

    Full Text Available Similarities have long been recognized between vernalization, the prolonged exposure to cold temperatures that promotes the floral transition in many plants, and the chilling requirement to release bud dormancy in woody plants of temperate climates. In both cases the extended chilling period occurring during winter is used to coordinate developmental events to the appropriate seasonal time. However, whether or not these processes share common regulatory components and molecular mechanisms remain largely unknown. Both gene function and association genetics studies in Populus are beginning to answer this question. In Populus, studies have revealed that orthologs of the antagonistic flowering time genes FT and CEN/TFL1 might have central roles in both processes. We review Populus seasonal shoot development related to dormancy release and the floral transition and evidence for FT/TFL1-mediated regulation of these processes to consider the question of regulatory overlap. In addition, we discuss the potential for and challenges to integrating functional and population genomics studies to uncover the regulatory mechanisms underpinning these processes in woody plant systems.

  12. Air distribution in office environment with asymmetric workstation layout using chilled beams

    Energy Technology Data Exchange (ETDEWEB)

    Koskela, Hannu; Haeggblom, Henna [Finnish Institute of Occupational Health, Lemminkaeisenkatu 14-18 B, 20520 Turku (Finland); Kosonen, Risto; Ruponen, Mika [Halton Oy, Niittyvillankuja 4, 01510 Vantaa (Finland)

    2010-09-15

    Air flow patterns and mean air speeds were studied under laboratory conditions representing a full scale open-plan office. Three basic conditions were tested: summer, spring/autumn and winter. Chilled beams were used to provide cooling, outdoor air supply and air distribution in the room. The heat sources had a notable influence on the flow pattern in the room causing large scale circulation and affecting the direction of inlet jets. The maximum air speed in the occupied zone was higher than the recommendations. The mean air speed was also high on at the floor level but low on at the head level. The air speed was highest in the summer case under high cooling load. Results indicate that especially with high heat loads, it is difficult to fulfill the targets of the existing standards in practice. Two main sources of draught risk were found: a) downfall of colliding inlet jets causing local maxima of air speed and b) large scale circulation caused by asymmetric layout of chilled beams and heat sources. The first phenomenon can cause local draught risk when the workstation is located in the downfall area. The flow pattern is not stable and the position of draught risk areas can change in time and also due to changes in room heat sources. The second phenomenon can cause more constant high air speeds on at the floor level. CFD-simulation was able to predict the general flow pattern but somewhat overestimated the air speed compared to measurements. (author)

  13. Laparoscopic artificial insemination in dairy sheep with chilled ...

    African Journals Online (AJOL)

    Jane

    2011-06-27

    C. Unilateral intrauterine ... conception rates to intrauterine insemination with chilled semen was relatively higher than Chios ewes. Key words: .... fertility trials and the effects of dilution methods on freezing ram semen in the ...

  14. Risky Drinking Can Put a Chill on Your Summer Fun

    Science.gov (United States)

    ... on Your Summer Fun Print version Risky Drinking Can Put a Chill on Your Summer Fun Summer ... adults involve the use of alcohol. 1 Swimmers can get in over their heads. Alcohol impairs judgment ...

  15. Cod and rainbow trout as freeze-chilled meal elements

    DEFF Research Database (Denmark)

    Jensen, Louise Helene Søgaard; Nielsen, Jette; Jørgensen, Bo

    2010-01-01

    Meal elements' are elements of a meal, e.g. portions of pre-fried meat, sauces, frozen fish or pre-processed vegetables typically prepared industrially. The meal elements are distributed to professional satellite kitchens, where the staff can combine them into complete meals. Freeze......-chilling is a process consisting of freezing and frozen storage followed by thawing and chilled storage. Combining the two would enable the manufacturer to produce large quantities of frozen meal elements to be released into the chill chain according to demand. We have studied the influence of freeze...... days of chilled storage, and the corresponding time for rainbow trout was 10 days. After this period the sensory quality decreased and chemical indicators of spoilage were seen to increase. CONCLUSION: The consistent quality during storage and the high-quality shelf life are practically applicable...

  16. GPM GROUND VALIDATION CHILL RADAR MC3E V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The CHILL radar data for the Midlatitude Continental Convective Clouds Experiment (MC3E) held in Oklahoma were collected while the NASA ER-2 aircraft conducted a...

  17. Performance of Chilled Beam with Radial Swirl Jet and Diffuse Ceiling Air Supply in Heating Mode

    DEFF Research Database (Denmark)

    Bertheussen, Bård; Mustakallio, Panu; Melikov, Arsen Krikor

    2013-01-01

    ). The room air temperature was kept at 21 °C. Tracer gas was used to simulate pollution from floor and desk. The experimental conditions comprised: 1) night time without heat sources in the room; the room air conditioning system was used to heat up the room; 2) heat load generated by an occupant (simulated...... by dressed thermal manikin) and a laptop; 3) heating by convectors positioned under the window (convectors used alone and convector used together with CSW supplying isothermal air for ventilation). The heat distribution provided by the systems was not effective compare to the distribution provided......The performance of diffuse ceiling air supply and chilled beam with swirl jet (CSW) in heating mode (winter situation) was studied and compared with regard to the generated indoor environment. An office mock-up with one occupant was simulated in a test room (4.5 x 3.95 x 3.5 m3 (L x W x H...

  18. Calculation of the Chilling Requirement for Air Conditioning in the Excavation Roadway

    Directory of Open Access Journals (Sweden)

    Yueping Qin

    2015-10-01

    Full Text Available To effectively improve the climate conditions of the excavation roadway in coal mine, the calculation of the chilling requirement taking air conditioning measures is extremely necessary. The temperature field of the surrounding rock with moving boundary in the excavation roadway was numerically simulated by using finite volume method. The unstable heat transfer coefficient between the surrounding rock and air flow was obtained via the previous calculation. According to the coupling effects of the air flow inside and outside air duct, the differential calculation mathematical model of air flow temperature in the excavation roadway was established. The chilling requirement was calculated with the selfdeveloped computer program for forecasting the required cooling capacity of the excavation roadway. A good air conditioning effect had been observed after applying the calculated results to field trial, which indicated that the prediction method and calculation procedure were reliable.

  19. Strigolactones positively regulate chilling tolerance in pea and in Arabidopsis.

    Science.gov (United States)

    Cooper, James W; Hu, Yan; Beyyoudh, Leila; Yildiz Dasgan, H; Kunert, Karl; Beveridge, Christine A; Foyer, Christine H

    2018-01-17

    Strigolactones (SL) fulfil important roles in plant development and stress tolerance. Here we characterised the role of SL in the dark chilling tolerance of pea and Arabidopsis by analysis of mutants that are defective in either SL synthesis or signalling. Pea mutants (rms3, rms4, rms5) had significantly greater shoot branching with higher leaf chlorophyll a/b ratios and carotenoid contents than the wild type. Exposure to dark chilling significantly decreased shoot fresh weights but increased leaf numbers in all lines. However, dark chilling treatments decreased biomass (dry weight) accumulation only in rms3 and rms5 shoots. Unlike the wild type plants, chilling-induced inhibition of photosynthetic carbon assimilation was observed in the rms lines and also in max3-9, max4-1, max2-1 mutants that are defective in SL synthesis or signalling. When grown on agar plates the max mutant rosettes accumulated less biomass than the wild type. The synthetic SL, GR24 decreased leaf area in the wild type, max3-9 and max4-1 mutants but not in max2-1 in the absence of stress. Moreover, a chilling-induced decrease in leaf area was observed in all the lines in the presence of GR24. We conclude that SL plays an important role in the control of dark chilling tolerance. This article is protected by copyright. All rights reserved.

  20. SolarChill - a solar PV refrigerator without battery

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, P.H.; Poulsen, S.; Katic, I. [Danish Technological Inst., Taastrup (Denmark)

    2004-07-01

    A solar powered refrigerator (SolarChill) has been developed in an international project involving Greenpeace International, GTZ, UNICEF, UNEP, WHO, industrial partners and Danish Technological Institute. The refrigerator is able to operate directly on solar PV panels, without battery or additional electronics, and is therefore suitable for locations where little maintenance and reliable operation is mandatory. The main objective of the SolarChill Project is to help deliver vaccines and refrigeration to the rural poor. To achieve this objective, the SolarChill Project developed - and plans to make freely available a versatile refrigeration technology that is environmentally sound, technologically reliable, and affordable. SolarChill does not use any fluorocarbons in its cooling system or in the insulation. For domestic and small business applications, another type of solar refrigerator is under development. This is an upright type, suitable for cool storage of food and beverages in areas where grid power is non-existent or unstable. The market potential for this type is thus present in industrialised countries as well as in countries under development. The unique feature of SolarChill is that energy is stored in ice instead of in batteries. An ice compartment keeps the cabinet at desired temperatures during the night. The paper describes the product development, possible SolarChill applications and experience with the two types of solar refrigerators, as well as results from the laboratory and field test. (orig.)

  1. An early response regulatory cluster induced by low temperature and hydrogen peroxide in seedlings of chilling-tolerant japonica rice

    Directory of Open Access Journals (Sweden)

    Jia Yulin

    2007-06-01

    Full Text Available Abstract Background Plants respond to low temperature through an intricately coordinated transcriptional network. The CBF/DREB-regulated network of genes has been shown to play a prominent role in freeze-tolerance of Arabidopsis through the process of cold acclimation (CA. Recent evidence also showed that the CBF/DREB regulon is not unique to CA but evolutionarily conserved between chilling-insensitive (temperate and chilling-sensitive (warm-season plants. In this study, the wide contrast in chilling sensitivity between indica and japonica rice was used as model to identify other regulatory clusters by integrative analysis of promoter architecture (ab initio and gene expression profiles. Results Transcriptome analysis in chilling tolerant japonica rice identified a subset of 121 'early response' genes that were upregulated during the initial 24 hours at 10°C. Among this group were four transcription factors including ROS-bZIP1 and another larger sub-group with a common feature of having as1/ocs-like elements in their promoters. Cold-induction of ROS-bZIP1 preceded the induction of as1/ocs-like element-containing genes and they were also induced by exogenous H2O2 at ambient temperature. Coordinated expression patterns and similar promoter architectures among the 'early response' genes suggest that they belong to a potential regulon (ROS-bZIP – as1/ocs regulatory module that responds to elevated levels of ROS during chilling stress. Cultivar-specific expression signatures of the candidate genes indicate a positive correlation between the activity of the putative regulon and genotypic variation in chilling tolerance. Conclusion A hypothetical model of an ROS-mediated regulon (ROS-bZIP – as1/ocs triggered by chilling stress was assembled in rice. Based on the current results, it appears that this regulon is independent of ABA and CBF/DREB, and that its activation has an important contribution in configuring the rapid responses of rice seedlings

  2. Characterizing and predicting ultrafine particle counts in Canadian classrooms during the winter months: model development and evaluation.

    Science.gov (United States)

    Weichenthal, Scott; Dufresne, André; Infante-Rivard, Claire; Joseph, Lawrence

    2008-03-01

    School classrooms are potentially important micro-environments for childhood exposures owing to the large amount of time children spend in these locations. While a number of airborne contaminants may be present in schools, to date few studies have examined ultrafine particle (0.02-1 microm) (UFP) levels in classrooms. In this study, our objective was to characterize UFP counts (cm(-3)) in classrooms during the winter months and to develop a model to predict such exposures based on ambient weather conditions and outdoor UFPs, as well as classroom characteristics such as size, temperature, relative humidity, and carbon dioxide levels. In total, UFP count data were collected on 60 occasions in 37 occupied classrooms at one elementary school and one secondary school in Pembroke, Ontario. On average, outdoor UFP levels exceeded indoor measures by 8989 cm(-3) (95% confidence interval (CI): 6382, 11596), and classroom UFP counts were similar at both schools with a combined average of 5017 cm(-3) (95% CI: 4300, 5734). Of the variables examined only wind speed and outdoor UFPs were important determinants of classrooms UFP levels. Specifically, each 10 km/h increase in wind speed corresponded to an 1873 cm(-3) (95% CI: 825, 2920) decrease in classroom UFP counts, and each 10000 cm(-3) increase in outdoor UFPs corresponded to a 1550 cm(-3) (95% CI: 930, 2171) increase in classroom UFP levels. However, high correlations between these two predictors meant that the independent effects of wind speed and outdoor UFPs could not be separated in multivariable models, and only outdoor UFP counts were included in the final predictive model. To evaluate model performance, classroom UFP counts were collected for 8 days at two new schools and compared to predicted values based on outdoor UFP measures. A moderate correlation was observed between measured and predicted classroom UFP counts (r=0.63) for both schools combined, but this relationship was not valid on days in which a strong

  3. Characterizing and predicting ultrafine particle counts in Canadian classrooms during the winter months: Model development and evaluation

    International Nuclear Information System (INIS)

    Weichenthal, Scott; Dufresne, Andre; Infante-Rivard, Claire; Joseph, Lawrence

    2008-01-01

    School classrooms are potentially important micro-environments for childhood exposures owing to the large amount of time children spend in these locations. While a number of airborne contaminants may be present in schools, to date few studies have examined ultrafine particle (0.02-1 μm) (UFP) levels in classrooms. In this study, our objective was to characterize UFP counts (cm -3 ) in classrooms during the winter months and to develop a model to predict such exposures based on ambient weather conditions and outdoor UFPs, as well as classroom characteristics such as size, temperature, relative humidity, and carbon dioxide levels. In total, UFP count data were collected on 60 occasions in 37 occupied classrooms at one elementary school and one secondary school in Pembroke, Ontario. On average, outdoor UFP levels exceeded indoor measures by 8989 cm -3 (95% confidence interval (CI): 6382, 11 596), and classroom UFP counts were similar at both schools with a combined average of 5017 cm -3 (95% CI: 4300, 5734). Of the variables examined only wind speed and outdoor UFPs were important determinants of classrooms UFP levels. Specifically, each 10 km/h increase in wind speed corresponded to an 1873 cm -3 (95% CI: 825, 2920) decrease in classroom UFP counts, and each 10 000 cm -3 increase in outdoor UFPs corresponded to a 1550 cm -3 (95% CI: 930, 2171) increase in classroom UFP levels. However, high correlations between these two predictors meant that the independent effects of wind speed and outdoor UFPs could not be separated in multivariable models, and only outdoor UFP counts were included in the final predictive model. To evaluate model performance, classroom UFP counts were collected for 8 days at two new schools and compared to predicted values based on outdoor UFP measures. A moderate correlation was observed between measured and predicted classroom UFP counts (r=0.63) for both schools combined, but this relationship was not valid on days in which a strong indoor UFP

  4. Mediterranean Thermohaline Response to Large-Scale Winter Atmospheric Forcing in a High-Resolution Ocean Model Simulation

    Science.gov (United States)

    Cusinato, Eleonora; Zanchettin, Davide; Sannino, Gianmaria; Rubino, Angelo

    2018-04-01

    Large-scale circulation anomalies over the North Atlantic and Euro-Mediterranean regions described by dominant climate modes, such as the North Atlantic Oscillation (NAO), the East Atlantic pattern (EA), the East Atlantic/Western Russian (EAWR) and the Mediterranean Oscillation Index (MOI), significantly affect interannual-to-decadal climatic and hydroclimatic variability in the Euro-Mediterranean region. However, whereas previous studies assessed the impact of such climate modes on air-sea heat and freshwater fluxes in the Mediterranean Sea, the propagation of these atmospheric forcing signals from the surface toward the interior and the abyss of the Mediterranean Sea remains unexplored. Here, we use a high-resolution ocean model simulation covering the 1979-2013 period to investigate spatial patterns and time scales of the Mediterranean thermohaline response to winter forcing from NAO, EA, EAWR and MOI. We find that these modes significantly imprint on the thermohaline properties in key areas of the Mediterranean Sea through a variety of mechanisms. Typically, density anomalies induced by all modes remain confined in the upper 600 m depth and remain significant for up to 18-24 months. One of the clearest propagation signals refers to the EA in the Adriatic and northern Ionian seas: There, negative EA anomalies are associated to an extensive positive density response, with anomalies that sink to the bottom of the South Adriatic Pit within a 2-year time. Other strong responses are the thermally driven responses to the EA in the Gulf of Lions and to the EAWR in the Aegean Sea. MOI and EAWR forcing of thermohaline properties in the Eastern Mediterranean sub-basins seems to be determined by reinforcement processes linked to the persistency of these modes in multiannual anomalous states. Our study also suggests that NAO, EA, EAWR and MOI could critically interfere with internal, deep and abyssal ocean dynamics and variability in the Mediterranean Sea.

  5. Online chilling effects in England and Wales

    Directory of Open Access Journals (Sweden)

    Judith Townend

    2014-04-01

    Full Text Available Open and free internet-based platforms are seen as an enabler of global free expression, releasing writers from commercial and space constraints. However, many are working without the assistance of an in-house lawyer, or other legal resources. This may lead to undue suppression of public interest material, with important implications for freedom of expression and the democratic function of media. Two online surveys among digital and online journalists in England and Wales in 2013 indicated that the majority of encounters with defamation and privacy law take place outside the courts, with few formally recorded legal actions. This was particularly evident in a sample of ‘hyperlocal’ and local community publishers. In light of the results, this paper calls for a reappraisal of overly simplistic judicial and media applications of the ‘chilling effect’ doctrine, in order to expose its subjectivities and complexities. Additionally, attention needs to be paid to global and cross-jurisdictional media-legal environments, in order to help develop better internet policy and legal frameworks for protecting legitimate expression.

  6. Modeling winter moth Operophtera brumata egg phenology: nonlinear effects of temperature and developmental stage on developmental rate

    NARCIS (Netherlands)

    Salis, Lucia; Lof, Marjolein; Van Asch, M.; Visser, Marcel E.

    2016-01-01

    Understanding the relationship between an insect's developmental rate and temperature is crucial to forecast insect phenology under climate change. In the winter moth Operophtera brumata timing of egg-hatching has severe fitness consequences on growth and reproduction as egg-hatching has to match

  7. Full-scale chilled pipeline frost heave testing, Fairbanks, Alaska, USA

    Energy Technology Data Exchange (ETDEWEB)

    Hazen, B. [Northern Engineering and Scientific, Anchorage, AK (United States); Isaacs, R.M. [RMI Associates, Camano Island, WA (United States); Myrick, J.E. [Myrick International, Tyler, TX (United States)

    2010-07-01

    This paper discussed a chilled pipeline frost-heave testing facility that was developed to simulate and record the rate of frost heave and frost-bulb growth for a buried, chilled pipeline in frost-susceptible soil and to determine the effectiveness of different mitigation techniques. The test facility, which was established near Fairbanks, Alaska, in 1979, has 10 test sections using 1.22-metre-diameter pipe. The testing involved un-insulated, insulated, and insulated with over-excavation and gravel berm configurations as well as the frost heave of the chilled pipeline. The test facility was described in detail. Frost heave and frost-bulb growth measurements from the first 10 months of testing were presented, as these are the first data to enter the public domain. The testing was undertaken to investigate the frost-heave relationships between sections, to better understand frost heave in permafrost, to explore possible mitigation options, and to advance the predicative capabilities of frost heave models. 12 refs., 1 tab., 17 figs.

  8. Winter Weather Emergencies

    Science.gov (United States)

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

  9. Winter maintenance performance measure.

    Science.gov (United States)

    2016-01-01

    The Winter Performance Index is a method of quantifying winter storm events and the DOTs response to them. : It is a valuable tool for evaluating the States maintenance practices, performing post-storm analysis, training : maintenance personnel...

  10. Inhibition of chloroplast protein synthesis following light chilling of tomato

    International Nuclear Information System (INIS)

    Kent, J.; Ort, D.

    1989-01-01

    In the present study we looked at the effects of a high light chill on the pulsed incorporation of 35 S methionine into total, stromal, and thylakoid proteins of lightly abraded leaflets of 18-21 day old tomato (Lycopersicon esculentum Mill ca. Floramerica) seedlings. Based on gel fluorographic patterns of marker proteins that are indicative of the net rates of chloroplast and cytoplasmic protein synthesis, there appears to be a nearly complete cessation of chloroplastic protein synthesis. No labeling is observed for either the stromal large subunit of Rubisco or the thylakoid-bound alpha and beta subunits of the coupling factor. One notable exception, however, appears to be the 32 kd, D1 protein. Its net synthetic rate remains high despite the inhibition of other chloroplastically synthesized proteins. The small subunit of Rubicso, LHCP-II, as well as several other proteins of known cytoplasmic origin, were still synthesized, albeit, at lower than control rates. Light chilling of chill-insensitive spinach produced a similar, but less dramatic differential behavior between chloroplastic and cytoplasmic protein synthesis. It appears, in chilling-sensitive plants, that chloroplast protein synthesis exhibits a greater sensitivity to low temperature inhibition than does cytoplasmic protein synthesis and that recovery of chloroplast protein synthesis may play an important role in recovery of photosynthetic activity following chilling

  11. Winter-to-winter variations in indoor radon

    International Nuclear Information System (INIS)

    Mose, D.G.; Mushrush, G.W.; Kline, S.W.

    1989-01-01

    Indoor radon concentrations in northern Virginia and central Maryland show a strong dependence on weather. Winter tends to be associated with higher than average indoor radon, and summer with lower than average. However, compared to the winter of 1986-1987, the winter of 1987-1988 was warmer and drier. Consequently, winter-to-winter indoor radon decreased by about 25%. This winter-to-winter decrease is unexpectedly large, and simulates winter-to-summer variations that have been reported

  12. Effect of irradiation on microbiological safety of chilled cooked dumpling

    International Nuclear Information System (INIS)

    Jia Chunfeng; Jia Yingmin; Gao Meixu; Sun Baozhong

    2005-01-01

    Chinese Dumplings are popular ethnic prepared meal in China. The effects of irradiation on the survival of Salmonella enteritidis, Listeria monocytogenes and Staphylococcus aureus, which are possible pathogenic bacteria in the chilled and cooked dumpling with vacuum package, were studied. The results showed that the D 10 values of Sal. enteritidis, Staph. aureus and L. monocytogenes were 0.31, 0.44 and 0.45 kGy, respectively. After 4 kGy irradiation, the hygienic and safe characters of the chilled and cooked dumpling were acceptable according to our national industrial standard. So the vacuum packaging and 4 kGy irradiation treatment might insure the safety of the chilled and cooked dumpling. (authors)

  13. Principle, function, experiences, hybrid chilled ceilings; Prinzip, Funktion, Erfahrungen. Hybrid-Kuehldecken

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, Uwe W. [Hochschule Luzern (Switzerland). Technik und Architektur

    2010-12-15

    Hybrid chilled ceilings combine a radiation chilled ceiling with thermal activations of a concrete ceiling. The activation permits the utilization of alternative and/or small cold generators for the efficient night cooling. The traditional chilled ceiling grants a speedy reaction to load variations as well as a reduction of the reverberation periods. In addition, the combination supplies a draught-free insertion of air. Beside established solutions, MWH Barcol-Air (Staefa, Switzerland) also offers project-specific hybrid chilled ceilings.

  14. Evaluation of an Extremum Seeking Control Based Optimization and Sequencing Strategy for a Chilled-water Plant

    OpenAIRE

    Zhao, Zhongfan; Li, Yaoyu; Mu, Baojie; Salsbury, Timothy I.; House, John M.

    2016-01-01

    Chilled-water plants with multiple chillers account for a significant fraction of energy use in large commercial buildings. Real-time optimization and sequencing of such plants is thus critical for building energy efficiency. Due to the cost and complexity associated with calibrating a chiller plant model to field operation, model-free control has become an attractive solution. Recently, Mu et al. (2015) proposed a model-free real-time optimization and sequencing strategy based on extremum se...

  15. Two-Pipe Chilled Beam System for Both Cooling and Heating of Office Buildings

    DEFF Research Database (Denmark)

    Afshari, Alireza; Gordnorouzi, Rouzbeh; Hultmark, Göran

    2013-01-01

    Simulations were performed to compare a conventional 4-pipe chilled beam system and a 2-pipe chilled beam system. The objective was to establish requirements, possibilities and limitations for a well-functioning 2-pipe chilled beam system for both cooling and heating of office buildings. The buil...

  16. 75 FR 32370 - Final Results of Antidumping Duty Changed Circumstances Review: Fresh and Chilled Atlantic Salmon...

    Science.gov (United States)

    2010-06-08

    ... Duty Changed Circumstances Review: Fresh and Chilled Atlantic Salmon from Norway AGENCY: Import... Duty Changed Circumstances Review: Fresh and Chilled Atlantic Salmon from Norway SUMMARY: On August 5... antidumping order on fresh and chilled Atlantic Salmon from Norway and preliminarily determined that Nordic...

  17. Adaptive Blending of Model and Observations for Automated Short-Range Forecasting: Examples from the Vancouver 2010 Olympic and Paralympic Winter Games

    Science.gov (United States)

    Bailey, Monika E.; Isaac, George A.; Gultepe, Ismail; Heckman, Ivan; Reid, Janti

    2014-01-01

    An automated short-range forecasting system, adaptive blending of observations and model (ABOM), was tested in real time during the 2010 Vancouver Olympic and Paralympic Winter Games in British Columbia. Data at 1-min time resolution were available from a newly established, dense network of surface observation stations. Climatological data were not available at these new stations. This, combined with output from new high-resolution numerical models, provided a unique and exciting setting to test nowcasting systems in mountainous terrain during winter weather conditions. The ABOM method blends extrapolations in time of recent local observations with numerical weather predictions (NWP) model predictions to generate short-range point forecasts of surface variables out to 6 h. The relative weights of the model forecast and the observation extrapolation are based on performance over recent history. The average performance of ABOM nowcasts during February and March 2010 was evaluated using standard scores and thresholds important for Olympic events. Significant improvements over the model forecasts alone were obtained for continuous variables such as temperature, relative humidity and wind speed. The small improvements to forecasts of variables such as visibility and ceiling, subject to discontinuous changes, are attributed to the persistence component of ABOM.

  18. Abnormal storm waves in the winter East/Japan Sea: generation process and hindcasting using an atmosphere-wind wave modelling system

    Directory of Open Access Journals (Sweden)

    H. S. Lee

    2010-04-01

    Full Text Available Abnormal storm waves cause coastal disasters along the coasts of Korean Peninsula and Japan in the East/Japan Sea (EJS in winter, arising due to developed low pressures during the East Asia winter monsoon. The generation of these abnormal storm waves during rough sea states were studied and hindcast using an atmosphere-wave coupled modelling system. Wind waves and swell due to developed low pressures were found to be the main components of abnormal storm waves. The meteorological conditions that generate these waves are classified into three patterns based on past literature that describes historical events as well as on numerical modelling. In hindcasting the abnormal storm waves, a bogussing scheme originally designed to simulate a tropical storm in a mesoscale meteorological model was introduced into the modelling system to enhance the resolution of developed low pressures. The modelling results with a bogussing scheme showed improvements in terms of resolved low pressure, surface wind field, and wave characteristics obtained with the wind field as an input.

  19. Chilled water optimization at Beek INEOS PVC Plant : ammonia cycle

    NARCIS (Netherlands)

    Karami Alaghinloo, B.

    2012-01-01

    In BEEK INEOS PVC plant, polymerization takes place in a suspension process in twenty reactors in five lines. As the reaction is exothermic, a 17MW chilled water unit (CWU) removing heat from reactors which are producing different grades in batch processes. The objective of the project was to

  20. Variation in fruit chilling injury among mango cultivars

    NARCIS (Netherlands)

    Phakawatmongkol, W.; Ketsa, S.; Doorn, van W.G.

    2004-01-01

    Mango(Mangifera indica L.) fruit of six cultivars ('Kaew', 'Rad', 'Okrong', 'Tongdum', 'Nam Dok Mai' and 'Nungklangwun') were stored at 4, 8 and 12degreesC (85-90% RH) and randomly sampled every 5 days. Chilling injury was manifested initially as a gray to brown discoloration of the peel, followed

  1. A computational study of low-head direct chill slab casting of aluminum alloy AA2024

    Science.gov (United States)

    Hasan, Mainul; Begum, Latifa

    2016-04-01

    The steady state casting of an industrial-sized AA2024 slab has been modeled for a vertical low-head direct chill caster. The previously verified 3-D CFD code is used to investigate the solidification phenomena of the said long-range alloy by varying the pouring temperature, casting speed and the metal-mold contact heat transfer coefficient from 654 to 702 °C, 60-180 mm/min, and 1.0-4.0 kW/(m2 K), respectively. The important predicted results are presented and thoroughly discussed.

  2. Winters fuels report

    International Nuclear Information System (INIS)

    1995-01-01

    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

  3. The effects of electron beam irradiation on sterilization and preservation of chilled pork

    International Nuclear Information System (INIS)

    Bai Yanhong; Mao Duobin; Zhao Dianbo; Zhang Xiaoyan; Li Quanshun; Yang Gongming

    2009-01-01

    S The effects of electron beam irradiation on the sterilization and preservation of chilled pork were studied. The aim of this investigation was to provide academic and technical basis for application of electron beam irradiation on meat industry. The response surface analysis was used with electron beam energy(X 1 ) and dose(X 2 ) as factors and colony form unit(Y) as responses. The results have been shown that the model of sterilization of chilled pork by electron beam irradiation can be expressed Y=3.78-0.24X 1 -0.13X 2 -0.16X 1 X 2 -0.18X 1 2 +0.15X 1 2 (R 2 =0.9755). It has been found there is a interaction between electron beam energy and absorbed doses, and the significance sequence of factors is absorbed dose>interaction> electron beam energy. When absorbed doses are in range from 3.23 kGy to 4.0 kGy and electron beam energy is in range from 2.3 MeV to 3.8 MeV, the colony form unit would drop 2 logarithm units. The shelf life of samples treated with electron beam irradiation is longer by about 12 d than that of control samples when the samples are stored at 4 degree C. When the samples are stored at 7∼10 degree C, shelf life of samples treated with electron beam irradiation is longer by about 9 d than that of control samples. The results showed that electron beam irradiation has the effects of sterilization and preservation on chilled pork. This study has been confirmed that the application of electron beam irradiation is very useful for meat industry. (authors)

  4. Improved energy performance of air cooled centrifugal chillers with variable chilled water flow

    International Nuclear Information System (INIS)

    Yu, F.W.; Chan, K.T.

    2008-01-01

    This paper considers how to apply optimum condensing temperature control and variable chilled water flow to increase the coefficient of performance (COP) of air cooled centrifugal chillers. A thermodynamic model for the chillers was developed and validated using a wide range of operating data and specifications. The model considers real process phenomena, including capacity control by the inlet guide vanes of the compressor and an algorithm to determine the number and speed of condenser fans staged based on a set point of condensing temperature. Based on the validated model, it was found that optimizing the control of condensing temperature and varying the evaporator's chilled water flow rate enable the COP to increase by 0.8-191.7%, depending on the load and ambient conditions. A cooling load profile of an office building in a subtropical climate was considered to assess the potential electricity savings resulting from the increased chiller COP and optimum staging of chillers and pumps. There is 16.3-21.0% reduction in the annual electricity consumption of the building's chiller plant. The results of this paper provide useful information on how to implement a low energy chiller plant

  5. Human Response to Personalized Ventilation Combined with Chilled Ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Marcol, Bartosz

    2014-01-01

    Personalized ventilation (PV) improves inhaled air quality, because it provides fresh air to each workstation and directly to occupant’s breathing zone. Previous research was focused on combining PV with additional total volume air distribution, i.e. mixing ventilation or displacement ventilation......, the use of radiant ceiling cooling will provide operative temperature lower than the air temperature and will improve further occupants’ thermal comfort at warm environment. Therefore combining PV with chilled ceiling may be an effective way to provide thermal comfort in rooms at temperature higher than...... temperature for chilled ceiling was 15,5/16,8°C at room air temperature of 26°C and 19,5/20,6°C at 28°C. During the experiment the subjects were performing typical office tasks at workstations with computers. Exposure included also increased activity level office work for a period of 25 min...

  6. Winter Bottom Trawl Survey

    Data.gov (United States)

    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 covered...

  7. Deer Wintering Areas

    Data.gov (United States)

    Vermont Center for Geographic Information — Deer winter habitat is critical to the long term survival of white-tailed deer (Odocoileus virginianus) in Vermont. Being near the northern extreme of the...

  8. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2013-02-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  9. Control of chilling tendency in grey cast iron reuse

    Directory of Open Access Journals (Sweden)

    Saliu Ojo Seidu

    2012-01-01

    Full Text Available In grey cast iron remelt and recycling, white iron can result in the cast product if careful control of the chilling tendency is not ensured. Many jobbing foundries are constrained in furnace types and available foundry additives that the operation always results in white irons. This study is towards ensuring grey iron is reproduced from cast iron scrap auto engine blocks, when using a diesel fired rotary furnace and a FeSi alloy for structural modification (inoculation. With varying addition rate of the FeSi alloy to the tapped molten metal, chill wedge tests were performed on two different wedge samples of type W (according to ASTM A367- wedge test with cooling modulus of 0.45 cm (W3½ and 0.54 cm (W4. The carbon equivalents for the test casts were within hypoeutectic range (3.85 wt. (% to 4.11 wt. (%. In the W4 wedge sample, at 2.0 wt. (% addition rate of the FeSi alloy, the relative clear chill was totally reduced to zero from 19.76%, while the relative mottled chill was brought down to 9.59% from 33.71%. The microstructure from the cast at this level of addition was free of carbidic phases; it shows randomly oriented graphite flakes evenly distributed in the iron matrix. Hardness assessment shows that increasing rate of FeSi addition results in decreasing hardness, with maximum effect at 2.0 wt. (% addition. With equivalent aspect ratio (cooling modulus in a target cast product, this addition rate for this FeSi alloy under this furnace condition will attain graphitized microstructure in the cast product.

  10. Estimating winter survival of winter wheat by simulations of plant frost tolerance

    NARCIS (Netherlands)

    Bergjord Olsen, A.K.; Persson, T.; Wit, de A.; Nkurunziza, L.; Sindhøj, E.; Eckersten, H.

    2018-01-01

    Based on soil temperature, snow depth and the grown cultivar's maximum attainable level of frost tolerance (LT50c), the FROSTOL model simulates development of frost tolerance (LT50) and winter damage, thereby enabling risk calculations for winter wheat survival. To explore the accuracy of this

  11. Genome wide identification of chilling responsive microRNAs in Prunus persica

    Directory of Open Access Journals (Sweden)

    Barakat Abdelali

    2012-09-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are small RNAs (sRNAs approximately 21 nucleotides in length that negatively control gene expression by cleaving or inhibiting the translation of target gene transcripts. Within this context, miRNAs and siRNAs are coming to the forefront as molecular mediators of gene regulation in plant responses to annual temperature cycling and cold stress. For this reason, we chose to identify and characterize the conserved and non-conserved miRNA component of peach (Prunus persica (L. Batsch focusing our efforts on both the recently released whole genome sequence of peach and sRNA transcriptome sequences from two tissues representing non-dormant leaves and dormant leaf buds. Conserved and non-conserved miRNAs, and their targets were identified. These sRNA resources were used to identify cold-responsive miRNAs whose gene targets co-localize with previously described QTLs for chilling requirement (CR. Results Analysis of 21 million peach sRNA reads allowed us to identify 157 and 230 conserved and non-conserved miRNA sequences. Among the non-conserved miRNAs, we identified 205 that seem to be specific to peach. Comparative genome analysis between peach and Arabidopsis showed that conserved miRNA families, with the exception of miR5021, are similar in size. Sixteen of these conserved miRNA families are deeply rooted in land plant phylogeny as they are present in mosses and/or lycophytes. Within the other conserved miRNA families, five families (miR1446, miR473, miR479, miR3629, and miR3627 were reported only in tree species (Populustrichocarpa, Citrus trifolia, and Prunus persica. Expression analysis identified several up-regulated or down-regulated miRNAs in winter buds versus young leaves. A search of the peach proteome allowed the prediction of target genes for most of the conserved miRNAs and a large fraction of non-conserved miRNAs. A fraction of predicted targets in peach have not been previously reported in other

  12. Thermoeconomic evaluation of air conditioning system with chilled water storage

    International Nuclear Information System (INIS)

    Lin, Hu; Li, Xin-hong; Cheng, Peng-sheng; Xu, Bu-gong

    2014-01-01

    Highlights: • A new thermoeconomic evaluation methodology has been presented. • The relationship between thermodynamic and economic performances has been revealed. • A key point for thermal storage technology further application is discovered. • A system has been analyzed via the new method and EUD method. - Abstract: As a good load shifting technology for power grid, chilled energy storage has been paid more and more attention, but it always consumes more energy than traditional air conditioning system, and the performance analysis is mostly from the viewpoint of peak-valley power price to get cost saving. The paper presents a thermoeconomic evaluation methodology for the system with chilled energy storage, by which thermodynamic performance influence on cost saving has been revealed. And a system with chilled storage has been analyzed, which can save more than 15% of power cost with no energy consumption increment, and just certain difference between peak and valley power prices can make the technology for good economic application. The results show that difference between peak and valley power prices is not the only factor on economic performance, thermodynamic performance of the storage system is the more important factor, and too big price difference is a barrier for its application, instead of for more cost saving. All of these give a new direction for thermal storage technology application

  13. Chill-inducing music enhances altruism in humans

    Directory of Open Access Journals (Sweden)

    Hajime eFukui

    2014-10-01

    Full Text Available Music is a universal feature of human cultures, and it has both fascinated and troubled many researchers. In this paper we show through the Dictator Game that an individual’s listening to preferred chill-inducing music may promote altruistic behavior that extends beyond the bounds of kin selection or reciprocal altruism. Participants were 22 undergraduate and postgraduate students who were divided into two groups, the In-group (IG and the Out-group (OG, and they acted as dictators. The dictators listened to their own preferred chill-inducing music, to music they disliked, or to silence, and then played the Dictator Game. In this hypothetical experiment, the dictators were given real money (which they did not keep and were asked to distribute it to the recipients, who were presented as stylized images of men and women displayed on a computer screen. The dictators played the Dictator Game both before and after listening to the music. Both male and female dictators gave more money after listening to their preferred music and less after listening to the music they disliked, whereas silence had no effect on the allocated amounts. The group to which the recipient belonged did not influence these trends. The results suggest that listening to preferred chill-inducing music promotes altruistic behavior.

  14. Chill-inducing music enhances altruism in humans.

    Science.gov (United States)

    Fukui, Hajime; Toyoshima, Kumiko

    2014-01-01

    Music is a universal feature of human cultures, and it has both fascinated and troubled many researchers. In this paper we show through the dictator game (DG) that an individual's listening to preferred "chill-inducing" music may promote altruistic behavior that extends beyond the bounds of kin selection or reciprocal altruism. Participants were 22 undergraduate and postgraduate students who were divided into two groups, the in-group and the out-group, and they acted as dictators. The dictators listened to their own preferred "chill-inducing" music, to music they disliked, or to silence, and then played the DG. In this hypothetical experiment, the dictators were given real money (which they did not keep) and were asked to distribute it to the recipients, who were presented as stylized images of men and women displayed on a computer screen. The dictators played the DG both before and after listening to the music. Both male and female dictators gave more money after listening to their preferred music and less after listening to the music they disliked, whereas silence had no effect on the allocated amounts. The group to which the recipient belonged did not influence these trends. The results suggest that listening to preferred "chill-inducing" music promotes altruistic behavior.

  15. Effects of high-pressure processing on Listeria monocytogenes , spoilage microflora and multiple compound quality indices in chilled cold-smoked salmon

    DEFF Research Database (Denmark)

    Lakshmanan, R.; Dalgaard, Paw

    2004-01-01

    of chilled CSS. Existing mathematical models allowed growth rates of L. monocytogenes and shelf-life of samples without high-pressure treatments to be predicted.Significance and Impact of the Study: High-pressure processing seems more appropriate for new types of salmon products than for a classical product...

  16. Application of DSSAT models for an agronomic adaptation strategy under climate change in Southern of Italy: optimum sowing and transplanting time for winter durum wheat and tomato

    Directory of Open Access Journals (Sweden)

    Domenico Ventrella

    2012-03-01

    Full Text Available Many climate change studies have been carried out in different parts of the world to assess climate change vulnerability and adaptation capacity of agricultural crops for determined environments characterized from climatic, pedological and agronomical point of view. The objective of this study was to analyse the productive response of winter durum wheat and tomato to climate change and sowing/transplanting time in one of most productive areas of Italy (i.e. Capitanata, Puglia, using CERES-Wheat and CROPGRO cropping system models. Three climatic datasets were used: i a single dataset (50 km x 50 km provided by the JRC European centre for the period 1975-2005; two datasets from HadCM3 for the IPCC A2 GHG scenario for time slices with +2°C (centred over 2030-2060 and +5°C (centred over 2070-2099, respectively. All three datasets were used to generate synthetic climate series using a weather simulator (model LARS-WG. No negative yield effects of climate change were observed for winter durum wheat with delayed sowing (from 330 to 345 DOY increasing the average dry matter grain yield under forecasted scenarios. Instead, the warmer temperatures were primarily shown to accelerate the phenology, resulting in decreased yield for tomato under the + 5°C future climate scenario. In general, under global temperature increase by 5°C, early transplanting times could minimize the negative impact of climate change on crop productivity but the intensity of this effect was not sufficient to restore the current production levels of tomato cultivated in southern Italy.

  17. Hydrogeological considerations in northern pipeline development. [Permafrost affected by hot or chilled pipeline

    Energy Technology Data Exchange (ETDEWEB)

    Harlan, R L

    1974-11-01

    Some of the hydrogeological implications of construction and operation of oil and gas pipelines in northern regions of Canada are considered in relation to their potential environmental impacts and those factors affecting the security of the pipeline itself. Although the extent to which water in permafrost participates in the subsurface flow regime has not been fully demonstrated, the role of liquid as well as vapor transport in frozen earth materials can be shown from theory to be highly significant; water movement rates in frozen soil are on the same order as those in unsaturated, unfrozen soil. Below 0/sup 0/C, the unfrozen water content in a fine-grained porous medium is dependent on temperature but independent of the total water content. The thermal gradient controls the rate and direction of water movement in permafrost. The groundwater stabilizes the streamflow and in the absence of large lakes provides the main source of flow during the winter. As groundwater is frequently confined by the permafrost, degradation of the permafrost can have significant consequences. The thaw bulb formed around a hot oil pipeline can induce liquefactioned flow of the thawed material. A chilled pipeline could restrict groundwater movement, resulting in buildup of artesian conditions and icings. The liberation and absorption of latent heat on freezing and thawing affects the thermal regime in the ground surface. Recommendations are given for pipeline construction and areas for further study pointed out. (DLC)

  18. Actual building energy use patterns and their implications for predictive modeling

    International Nuclear Information System (INIS)

    Heidarinejad, Mohammad; Cedeño-Laurent, Jose G.; Wentz, Joshua R.; Rekstad, Nicholas M.; Spengler, John D.; Srebric, Jelena

    2017-01-01

    Highlights: • Developed three building categories based on energy use patterns of campus buildings. • Evaluated implication of temporal energy data granularity on predictive modeling. • Demonstrated importance of monitoring daily chilled water consumption. • Identified interval electricity data as an indicator of building operation schedules. • Demonstrated a calibration process for energy modeling of a campus building. - Abstract: The main goal of this study is to understand the patterns in which commercial buildings consume energy, rather than evaluating building energy use based on aggregate utility bills typically linked to building principal tenant activity or occupancy type. The energy consumption patterns define buildings as externally-load, internally-load, or mixed-load dominated buildings. Penn State and Harvard campuses serve as case studies for this particular research project. The buildings in these two campuses use steam, chilled water, and electricity as energy commodities and maintain databases of different resolutions to include minute, hourly, daily, and monthly data instances depending on the commodity and available data acquisition system. The results of this study show monthly steam consumption directly correlates to outdoor environmental conditions for 88% of the studied buildings, while chilled water consumption has negligible correlation to the outdoor environmental conditions. Thus, in terms of monthly chilled water consumption, 86% of buildings are internally-load and mixed-load dominated, respectively. Chilled water consumption is better suited for the daily analyses compared to the monthly and hourly analyses. While the influence of building operation schedules affects the analyses at the hourly level, the monthly chilled water consumptions are not good indicators of the building energy consumption patterns. Electricity consumption at the monthly (or seasonal) level can support the building energy simulation tools for the

  19. Experimental research and numerical simulation on cryogenic line chill-down process

    Science.gov (United States)

    Jin, Lingxue; Cho, Hyokjin; Lee, Cheonkyu; Jeong, Sangkwon

    2018-01-01

    The empirical heat transfer correlations are suggested for the fast cool down process of the cryogenic transfer line from room temperature to cryogenic temperature. The correlations include the heat transfer coefficient (HTC) correlations for single-phase gas convection and film boiling regimes, minimum heat flux (MHF) temperature, critical heat flux (CHF) temperature and CHF. The correlations are obtained from the experimental measurements. The experiments are conducted on a 12.7 mm outer diameter (OD), 1.25 mm wall thickness and 7 m long stainless steel horizontal pipe with liquid nitrogen (LN2). The effect of the lengthwise position is verified by measuring the temperature profiles in near the inlet and the outlet of the transfer line. The newly suggested heat transfer correlations are applied to the one-dimensional homogeneous transient model to simulate the cryogenic line chill-down process, and the chill-down time and the cryogen consumption are well predicted in the mass flux range from 26.0 kg/m2 s to 73.6 kg/m2 s through the correlations.

  20. Modeling winter wheat phenological responses to water deficits in the Unified Plant Growth Model (UPGM) component of the spatially distributed Agricultural Ecosystem Services (AgES) model

    Science.gov (United States)

    Accurately predicting phenology in crop simulation models is critical for correctly simulating crop production. While extensive work in modeling phenology has focused on the temperature response function (resulting in robust phenology models), limited work on quantifying the phenological responses t...

  1. Pre-symptomatic transcriptome changes during cold storage of chilling sensitive and resistant peach cultivars to elucidate chilling injury mechanisms

    OpenAIRE

    Puig, Clara Pons; Dagar, Anurag; Marti Ibanez, Cristina; Singh, Vikram; Crisosto, Carlos H; Friedman, Haya; Lurie, Susan; Granell, Antonio

    2015-01-01

    Background: Cold storage induces chilling injury (CI) disorders in peach fruit (woolliness/mealiness, flesh browning and reddening/bleeding) manifested when ripened at shelf life. To gain insight into the mechanisms underlying CI, we analyzed the transcriptome of 'Oded' (high tolerant) and 'Hermoza' (relatively tolerant to woolliness, but sensitive to browning and bleeding) peach cultivars at pre-symptomatic stages. The expression profiles were compared and validated with two previously analy...

  2. Computation of large scale currents in the Arabian Sea during winter using a semi-diagnostic model

    Digital Repository Service at National Institute of Oceanography (India)

    Shaji, C.; Bahulayan, N.; Rao, A.D.; Dube, S.K.

    A 3-dimensional, semi-diagnostic model with 331 levels in the vertical has been used for the computation of climatic circulation in the western tropical Indian Ocean. Model is driven with the seasonal mean data on wind stress, temperature...

  3. Comparison of tissue deterioration of ripening banana fruit (Musa spp., AAA group, Cavendish subgroup) under chilling and non-chilling temperatures.

    Science.gov (United States)

    Ramírez-Sánchez, Maricruz; Huber, Donald J; Vallejos, Carlos E

    2018-03-08

    In fleshy fruits, induced programmed cell death (PCD) has been observed in heat-treated tomato, and in ethylene-treated and low-temperature exposure in immature cucumber. No other fleshy fruit has been evaluated for chilling-injury-induced PCD, especially mature fruit with full ripening capacity. The purpose of this research was to identify and evaluate the presence of PCD processes during the development of low-temperature-induced physiopathy of banana fruit. Exposure of fruit to 5 °C for 4 days induced degradative processes similar to those occurring during ripening and overripening of non-chilled fruit. Nuclease from banana peel showed activity in both DNA substrates and RNA substrates. No exclusive low-temperature-induced proteases and nucleases were observed. DNA of chilled peel showed earlier signs of degradation and higher levels of DNA tailing during overripening. This study shows that exposure to low temperatures did not induce a pattern of degradative processes that differed from that occurring during ripening and overripening of non-chilled fruit. DNA showed earlier signs of degradation and higher levels of DNA tailing. Nuclease activity analysis showed bifunctionality in both chilled and non-chilled tissue and no chilling-exclusive protease and nuclease. Fleshy fruit might use their available resources on degradative processes and adjust them depending on environmental conditions. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

  4. THE EFFECTS OF SPRAY-CHILLING ASSOCIATED TO CONVENTIONAL CHILLING ON MASS LOSS, BACTERIOLOGYCAL AND PHYSICO-CHEMICAL QUALITY OF BEEF CARCASS

    Directory of Open Access Journals (Sweden)

    Moacir Evandro Lage

    2006-10-01

    Full Text Available The purpose of this study was to verify the effect of conventional air chilling associated to intermittent spray-chilling treatment, on weight loss, physico-chemical and bacteriological quality of beef carcasses. Two plants of commercial beef slaughterhouse located in Goiânia and fiscalized by the Federal Inspection Service were used to develop the research. The spray-chilling treatment was accomplished in an intermittent way, commanded by acontrolled logical program, with cycles of 90 seconds, in intervals of 30 minutes, during the first 4 hours of the chilling process. Physico-chemical and bacteriological analysis were made in spray-chilled water and carcasses samples, according to recommendation of the effective legislation.The average values of carcasses weight loss of treatment group were lower to the ones verified for the control group,in both plants, A and B, (P < 0,001, showing a high economic potential. As a conclusion of physico-chemical and bacteriological analysis results of water and meat samples, it is clear that the technology of chilling beef carcasses inthe conventional system associated to spraying did not interfere in the quality of meat, and it can become an analysis object on part of official organs for sanitary regulation and fiscalization, for its definitive adoption. KEY WORDS: Spray-chilling, shrinkage, beef carcass.

  5. Impact of partly ice-free Lake Ladoga on temperature and cloudiness in an anticyclonic winter situation – a case study using a limited area model

    Directory of Open Access Journals (Sweden)

    Kalle Eerola

    2014-12-01

    Full Text Available At the end of January 2012, a low-level cloud from partly ice-free Lake Ladoga caused very variable 2-m temperatures in Eastern Finland. The sensitivity of the High Resolution Limited Area Model (HIRLAM to the lake surface conditions was tested in this winter anticyclonic situation. The lake appeared to be (incorrectly totally covered by ice when the lake surface was described with its climatology. Both parametrisation of the lake surface state by using a lake model integrated to the NWP system and objective analysis based on satellite observations independently resulted in a correct description of the partly ice-free Lake Ladoga. In these cases, HIRLAM model forecasts were able to predict cloud formation and its movement as well as 2-m temperature variations in a realistic way. Three main conclusions were drawn. First, HIRLAM could predict the effect of Lake Ladoga on local weather, when the lake surface state was known. Second, the current parametrisation methods of air–surface interactions led to a reliable result in conditions where the different physical processes (local surface processes, radiation and turbulence were not strong, but their combined effect was important. Third, these results encourage work for a better description of the lake surface state in NWP models by fully utilising satellite observations, combined with advanced lake parametrisation and data assimilation methods.

  6. The nuclear winter

    International Nuclear Information System (INIS)

    Velikhow, Y.P.

    1986-01-01

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

  7. Modeling Coupled Water and Heat Transport in the Root Zone of Winter Wheat under Non-Isothermal Conditions

    Directory of Open Access Journals (Sweden)

    Rong Ren

    2017-04-01

    Full Text Available Temperature is an integral part of soil quality in terms of moisture content; coupling between water and heat can render a soil fertile, and plays a role in water conservation. Although it is widely recognized that both water and heat transport are fundamental factors in the quantification of soil mass and energy balance, their computation is still limited in most models or practical applications in the root zone under non-isothermal conditions. This research was conducted to: (a implement a fully coupled mathematical model that contains the full coupled process of soil water and heat transport with plants focused on the influence of temperature gradient on soil water redistribution and on the influence of change in soil water movement on soil heat flux transport; (b verify the mathematical model with detailed field monitoring data; and (c analyze the accuracy of the model. Results show the high accuracy of the model in predicting the actual changes in soil water content and temperature as a function of time and soil depth. Moreover, the model can accurately reflect changes in soil moisture and heat transfer in different periods. With only a few empirical parameters, the proposed model will serve as guide in the field of surface irrigation.

  8. Assessment of Brown Bear\\'s (Ursus arctos syriacus Winter Habitat Using Geographically Weighted Regression and Generalized Linear Model in South of Iran

    Directory of Open Access Journals (Sweden)

    A. A. Zarei

    2016-03-01

    Full Text Available Winter dens are one of the important components of brown bear's (Ursus arctos syriacus habitat, affecting their reproduction and survival. Therefore identification of factors affecting the habitat selection and suitable denning areas in the conservation of our largest carnivore is necessary. We used Geographically Weighted Logistic Regression (GWLR and Generalized Linear Model (GLM for modeling suitability of denning habitat in Kouhkhom region in Fars province. In the present research, 20 dens (presence locations and 20 caves where signs of bear were not found (absence locations were used as dependent variables and six environmental factors were used for each location as independent variables. The results of GLM showed that variables of distance to settlements, altitude, and distance to water were the most important parameters affecting suitability of the brown bear's denning habitat. The results of GWLR showed the significant local variations in the relationship between occurrence of brown bear dens and the variable of distance to settlements. Based on the results of both models, suitable habitats for denning of the species are impassable areas in the mountains and inaccessible for humans.

  9. Evaluation of the Community Multiscale Air Quality Model for Simulating Winter Ozone Formation in the Uinta Basin with Intensive Oil and Gas Production

    Science.gov (United States)

    Matichuk, R.; Tonnesen, G.; Luecken, D.; Roselle, S. J.; Napelenok, S. L.; Baker, K. R.; Gilliam, R. C.; Misenis, C.; Murphy, B.; Schwede, D. B.

    2015-12-01

    The western United States is an important source of domestic energy resources. One of the primary environmental impacts associated with oil and natural gas production is related to air emission releases of a number of air pollutants. Some of these pollutants are important precursors to the formation of ground-level ozone. To better understand ozone impacts and other air quality issues, photochemical air quality models are used to simulate the changes in pollutant concentrations in the atmosphere on local, regional, and national spatial scales. These models are important for air quality management because they assist in identifying source contributions to air quality problems and designing effective strategies to reduce harmful air pollutants. The success of predicting oil and natural gas air quality impacts depends on the accuracy of the input information, including emissions inventories, meteorological information, and boundary conditions. The treatment of chemical and physical processes within these models is equally important. However, given the limited amount of data collected for oil and natural gas production emissions in the past and the complex terrain and meteorological conditions in western states, the ability of these models to accurately predict pollution concentrations from these sources is uncertain. Therefore, this presentation will focus on understanding the Community Multiscale Air Quality (CMAQ) model's ability to predict air quality impacts associated with oil and natural gas production and its sensitivity to input uncertainties. The results will focus on winter ozone issues in the Uinta Basin, Utah and identify the factors contributing to model performance issues. The results of this study will help support future air quality model development, policy and regulatory decisions for the oil and gas sector.

  10. Diagnosing sea ice from the north american multi model ensemble and implications on mid-latitude winter climate

    Science.gov (United States)

    Elders, Akiko; Pegion, Kathy

    2017-12-01

    Arctic sea ice plays an important role in the climate system, moderating the exchange of energy and moisture between the ocean and the atmosphere. An emerging area of research investigates how changes, particularly declines, in sea ice extent (SIE) impact climate in regions local to and remote from the Arctic. Therefore, both observations and model estimates of sea ice become important. This study investigates the skill of sea ice predictions from models participating in the North American Multi-Model Ensemble (NMME) project. Three of the models in this project provide sea-ice predictions. The ensemble average of these models is used to determine seasonal climate impacts on surface air temperature (SAT) and sea level pressure (SLP) in remote regions such as the mid-latitudes. It is found that declines in fall SIE are associated with cold temperatures in the mid-latitudes and pressure patterns across the Arctic and mid-latitudes similar to the negative phase of the Arctic Oscillation (AO). These findings are consistent with other studies that have investigated the relationship between declines in SIE and mid-latitude weather and climate. In an attempt to include additional NMME models for sea-ice predictions, a proxy for SIE is used to estimate ice extent in the remaining models, using sea surface temperature (SST). It is found that SST is a reasonable proxy for SIE estimation when compared to model SIE forecasts and observations. The proxy sea-ice estimates also show similar relationships to mid-latitude temperature and pressure as the actual sea-ice predictions.

  11. Payment mechanisms for winter road maintenance services

    Directory of Open Access Journals (Sweden)

    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.

  12. Simulation of winter wheat yield and its variability in different climates of Europe: A comparison of eight crop growth models

    DEFF Research Database (Denmark)

    Palosuo, Taru; Kersebaum, Kurt Christian; Angulo, Carlos

    2011-01-01

    observations at all sites and in all years, and none could unequivocally be labelled robust and accurate in terms of yield prediction across different environments and crop cultivars with only minimum calibration. The best performance regarding yield estimation was for DAISY and DSSAT, for which the RMSE...... and WOFOST furnished high total above-ground biomass estimates, whereas CROPSYST, DSSAT and FASSET provided low total above-ground estimates. Consequently, DSSAT and FASSET produced very high harvest index values, followed by HERMES and WOFOST. APES and DAISY, on the other hand, returned low harvest index...... of grain yield estimates provided by the models for all sites and years reflects substantial uncertainties in model estimates achieved with only minimum calibration. Mean predictions from the eight models, on the other hand, were in good agreement with measured data. This applies to both results across all...

  13. Employment and winter construction

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place; Larsen, Jacob Norvig

    2011-01-01

    Reduced seasonal building activity in the construction sector is often assumed to be related to hard winter conditions for building activities and poor working conditions for construction workers, resulting in higher costs and poor quality of building products, particularly in the northern hemisp...... of contracts for workers is more likely to explain differences in seasonal activity than climatic or technological factors....

  14. Titan's Emergence from Winter

    Science.gov (United States)

    Flasar, F. Michael; Achterberg, Richard; Jennings, Donald; Schinder, Paul

    2011-01-01

    We summarize the changes in Titans thermal structure derived from Cassini CIRS and radio-occultation data during the transition from winter to early spring. Titan's surface, and middle atmosphere show noticeable seasonal change, whereas that in most of the troposphere is mated. This can be understood in terms of the relatively small radiative relaxation time in the middle atmosphere and much larger time scale in the troposphere. The surface exhibits seasonal change because the heat capacity in an annual skin depth is much smaller than that in the lowest scale height of the troposphere. Surface temperatures rise 1 K at raid and high latitudes in the winter northern hemisphere and cool in the southern hemisphere. Changes in in the middle atmosphere are more complicated. Temperatures in the middle stratosphere (approximately 1 mbar) increase by a few kelvin at mid northern latitudes, but those at high latitudes first increase as that region moves out of winter shadow, and then decrease. This probably results from the combined effect of increased solar heating as the suit moves higher in the sky and the decreased adiabatic warming as the sinking motions associated with the cross-equatorial meridional cell weaken. Consistent with this interpretation, the warm temperatures observed higher up at the winter polar stratopause cool significantly.

  15. Observation and Modelling of the OH, HO2 and RO2 Radicals at a Regional Site of Beijing in Winter 2016.

    Science.gov (United States)

    Tan, Z.; Lu, K.; Ma, X.; Bohn, B.; Hofzumahaus, A.; Broch, S.; Fuchs, H.; Holland, F.; Liu, Y.; Li, X.; Novelli, A.; Rohrer, F.; Wang, H.; Wu, Y.; Shao, M.; Zeng, L.; Kiendler-Scharr, A.; Wahner, A.; Zhang, Y.

    2017-12-01

    A comprehensive field campaign was carried out in winter 2016 in the campus of UCAS (University of Chinese Academy of Science), located in a small town 60 km northeast of urban Beijing. Concentrations of OH, HO2 and RO2 radicals as well as the total OH reactivity were measured by a laser induced fluorescence instrument. Maximum hourly averaged OH, HO2 and RO2 radical concentrations were (3±2)×106cm-3, (8±6)×107 cm-3 and (7±5)×107 cm-3, respectively. These radical concentrations were smaller than those observed during summer because of the reduced solar radiation. A chemical modulation device to separate atmospheric OH radicals from any interfering species was applied for few days showing negligible interference for both clean and polluted air masses.HONO and HCHO photolysis were found to be the most important primary sources of ROx radicals. CO and NOx were the important OH reactants which contributed more than half of the total OH reactivity. The relative high OH concentrations in polluted episode enabled a fast oxidation of fresh emitted pollutants and the formation of secondary air products. The observed radical concentrations were compared with the results from a chemical box model. The model is capable of reproducing radical concentrations for moderate NOx conditions but larger discrepancies are observed for both low and high NOx regimes for the peroxy radical concentrations. The underestimation of RO2 radical concentrations for high NOx conditions is discussed in the context of recent campaigns.

  16. The usefulness of fungicide mixtures and alternation for delaying the selection for resistance in populations of Mycosphaerella graminicola on winter wheat: a modeling analysis.

    Science.gov (United States)

    Hobbelen, P H F; Paveley, N D; Oliver, R P; van den Bosch, F

    2013-07-01

    A fungicide resistance model (reported and tested previously) was amended to describe the development of resistance in Mycosphaerella graminicola populations in winter wheat (Triticum aestivum) crops in two sets of fields, connected by spore dispersal. The model was used to evaluate the usefulness of concurrent, alternating, or mixture use of two high-resistance-risk fungicides as resistance management strategies. We determined the effect on the usefulness of each strategy of (i) fitness costs of resistance, (ii) partial resistance to fungicides, (iii) differences in the dose-response curves and decay rates between fungicides, and (iv) different frequencies of the double-resistant strain at the start of a treatment strategy. Parameter values for the quinine outside inhibitor pyraclostrobin were used to represent two fungicides with differing modes of action. The effectiveness of each strategy was quantified as the maximum number of growing seasons that disease was effectively controlled in both sets of fields. For all scenarios, the maximum effective lives achieved by the use of the strategies were in the order mixtures ≥ alternation ≥ concurrent use. Mixtures were of particular benefit where the pathogen strain resistant to both modes of action incurred a fitness penalty or was present at a low initial frequency.

  17. Assessing the impacts of future climate conditions on the effectiveness of winter cover crops in reducing nitrate loads into the Chesapeake Bay Watershed using SWAT model

    Science.gov (United States)

    Lee, Sangchul; Sadeghi, Ali M.; Yeo, In-Young; McCarty, Gregory W.; Hively, W. Dean

    2017-01-01

    Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrate loads from agriculture. Accordingly, the question remains whether WCCs are sufficient to mitigate increased nutrient loads caused by FCCs. In this study, we assessed the impacts of FCCs on WCC nitrate reduction efficiency on the Coastal Plain of the CBW using Soil and Water Assessment Tool (SWAT) model. Three FCC scenarios (2085 – 2098) were prepared using General Circulation Models (GCMs), considering three Intergovernmnental Panel on Climate Change (IPCC) Special Report on Emissions Scenarios (SRES) greenhouse gas emission scenarios. We also developed six representative WCC implementation scenarios based on the most commonly used planting dates and species of WCCs in this region. Simulation results showed that WCC biomass increased by ~ 58 % under FCC scenarios, due to climate conditions conducive to the WCC growth. Prior to implementing WCCs, annual nitrate loads increased by ~ 43 % under FCC scenarios compared to the baseline scenario (2001 – 2014). When WCCs were planted, annual nitrate loads were substantially reduced by ~ 48 % and WCC nitrate reduction efficiency water ~ 5 % higher under FCC scenarios relative to the baseline. The increase rate of WCC nitrate reduction efficiency varied by FCC scenarios and WCC planting methods. As CO2 concentration was higher and winters were warmer under FCC scenarios, WCCs had greater biomass and therefore showed higher nitrate reduction efficiency. In response to FCC scenarios, the performance of less effective WCC practices (e.g., barley, wheat, and late planting) under the baseline indicated ~ 14 % higher increase rate of nitrate reduction efficiency compared to ones with better effectiveness under the baseline (e

  18. Investigation of transient chill down phenomena in tubes using liquid nitrogen

    Science.gov (United States)

    Shukla, A. K.; Sridharan, Arunkumar; Atrey, M. D.

    2017-12-01

    Chill down of cryogenic transfer lines is a crucial part of cryogenic propulsion as chill down ensures transfer of single phase fluid to the storage tanks of cryogenic engines. It also ensures single phase liquid flow at the start of the engine. Chill down time depends on several parameters such as length of the pipe, pipe diameter, orientation, mass flux etc. To understand the effect of these parameters, experiments are carried out in a set up designed and fabricated at Indian Institute of Technology Bombay using tubes of two different diameters. Experiments are conducted at different inlet pressures and mass flow rate values to understand their effect. Two different pipe sizes are taken to study the effect of variation in diameter on chill down time and quantity of cryogen required. Different orientations are taken to understand their effect on the chill down time, heat transfer coefficient and critical heat flux for the same inlet pressure and mass flux. Pipe inner wall temperature, heat transfer coefficient for different boiling regimes and critical heat flux are calculated based on measured outer surface temperature history for each case. A one dimensional energy conservation equation is solved for transient chill down process considering constant mass flux and inlet pressure to predict the chill down time. Temperature variation during chill down obtained from the numerical simulations are compared with the measured temperature history.

  19. 9 CFR 381.66 - Temperatures and chilling and freezing procedures.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Temperatures and chilling and freezing procedures. 381.66 Section 381.66 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT... Procedures § 381.66 Temperatures and chilling and freezing procedures. (a) General. Temperatures and...

  20. Response of spring type wheat (triticum aestivum l.) cultivars to different chilling treatments

    Science.gov (United States)

    Late sowing of wheat in autumn due to environmental conditions or late harvesting of cotton crop results in substantial yield loss. It may be attributed to non-fulfillment of chilling requirements. The present study was conducted to identify the chilling requirement of autumn sown cultivars of wheat...

  1. Regulation of photosynthesis and antioxidant metabolism in maize leaves at optimal and chilling temperatures : review

    NARCIS (Netherlands)

    Foyer, C.H.; VanAcker, H.; Gomez, L.D.; Harbinson, J.

    2002-01-01

    Maize (Zea mays L.) is a chilling (below 15 °C) sensitive plant that shows little capacity to acclimate to low growth temperatures. Maize leaves are extremely sensitive to chilling injury, which usually results in premature leaf senescence. Leaves exposed to temperatures below 10 °C in the light

  2. Physiological girdling of pine trees via phloem chilling: proof of concept

    Science.gov (United States)

    Kurt Johnsen; Chris Maier; Felipe Sanchez; Peter Anderson; John Butnor; Richard Waring; Sune Linder

    2007-01-01

    Quantifying below-ground carbon (C) allocation is particularly difficult as methods usually disturb the root– mycorrhizal–soil continuum. We reduced C allocation below ground of loblolly pine trees by: (1) physically girdling trees and (2) physiologically girdling pine trees by chilling the phloem. Chilling reduced cambium temperatures by approximately 18 °C. Both...

  3. Chemical Changes of Short-Bodied Mackerel (Rastrelliger Brachysoma) Muscle at Chilled and Frozen Storage

    International Nuclear Information System (INIS)

    Emilia Azrina Mohd Bakri; Norizzah Abd Rashid; Seng, C.C.; Anida Yusoff; Fazilah Fazilin Juhari

    2016-01-01

    This study was carried out to evaluate the chemical changes in short-bodied mackerel during chilled (4 degree Celcius) and frozen (-18 degree Celicus) storage for 18 days. The chemical changes were monitored at three days interval using Peroxide Value (PV), Thiobarbituric Acid (TBA), Total Volatile Base Nitrogen (TVBN) and Trimethylamine (TMA) tests. The PV of both chilled and frozen mackerel significantly increased (p<0.05) with storage time and the rate was significantly higher in chilled than frozen mackerel. Based on the results, the chilled and frozen mackerel started to become rancid at day 15 and day 18, respectively. Similar trend was observed for TBA value, where the malonaldehyde content significantly increased (p<0.05) for both chilled and frozen mackerel with storage time, and the rate of increase was higher in chilled than frozen mackerel. The TVBN and TMA of chilled mackerel increased significantly during storage time, but the values declined in frozen mackerel which might be due to inhibitory effects of freezing on the bacterial activities and hence avoid accumulation of TMA. Based on the chemical analyses, chilled mackerel spoiled rapidly compared to frozen mackerel. (author)

  4. Winter Dew Harvest in Mexico City

    Directory of Open Access Journals (Sweden)

    Arias-Torres Jorge Ernesto

    2015-12-01

    Full Text Available This study presents experimental and theoretical results of winter dew harvest in México 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.

  5. Development of transport technique by chilling for melon fly, Bactrocera cucurbitae Coquillett (Diptela: Dephritidae)

    International Nuclear Information System (INIS)

    Tanahara, A.; Kirihara, S.; Kakinohana, H.

    1994-01-01

    To evaluate the effect of chilling on mass-reared melon fly, Bactrocera cucurbitae COQ., groups of adult flies were exposed to 3, 0.5, -2.2 and -3.5°C for 6, 12, 24 and 48h. The recovery and longevity of adult chilled for less than 24h at about 0.5°C was not adversely affected. A special container for chilled flies, which was able to keep the temperature below 10°C for 4h, was designed for their long-distance transport. The longevities of flies using aerial distribution by helicopter and hand release on the ground using the chilled transport container were compared with direct release from an emergence box without chilling at Miyagi Island in Okinawa Prefecture. There were no significant differences in longevity between the three release methods

  6. Investigating the role of chemical and physical processes on organic aerosol modelling with CAMx in the Po Valley during a winter episode

    Science.gov (United States)

    Meroni, A.; Pirovano, G.; Gilardoni, S.; Lonati, G.; Colombi, C.; Gianelle, V.; Paglione, M.; Poluzzi, V.; Riva, G. M.; Toppetti, A.

    2017-12-01

    Traditional aerosol mechanisms underestimate the observed organic aerosol concentration, especially due to the lack of information on secondary organic aerosol (SOA) formation and processing. In this study we evaluate the chemical and transport model CAMx during a one-month in winter (February 2013) over a 5 km resolution domain, covering the whole Po valley (Northern Italy). This works aims at investigating the effects of chemical and physical atmospheric processing on modelling results and, in particular, to evaluate the CAMx sensitivity to organic aerosol (OA) modelling schemes: we will compare the recent 1.5D-VBS algorithm (CAMx-VBS) with the traditional Odum 2-product model (CAMx-SOAP). Additionally, the thorough diagnostic analysis of the reproduction of meteorology, precursors and aerosol components was intended to point put strength and weaknesses of the modelling system and address its improvement. Firstly, we evaluate model performance for criteria PM concentration. PM10 concentration was underestimated both by CAMx-SOAP and even more by CAMx-VBS, with the latter showing a bias ranging between -4.7 and -7.1 μg m-3. PM2.5 model performance was to some extent better than PM10, showing a mean bias ranging between -0.5 μg m-3 at rural sites and -5.5 μg m-3 at urban and suburban sites. CAMx performance for OA was clearly worse than for the other PM compounds (negative bias ranging between -40% and -75%). The comparisons of model results with OA sources (identified by PMF analysis) shows that the VBS scheme underestimates freshly emitted organic aerosol while SOAP overestimates. The VBS scheme correctly reproduces biomass burning (BBOA) contributions to primary OA concentrations (POA). In contrast VBS slightly underestimates the contribution from fossil-fuel combustion (HOA), indicating that POA emissions related to road transport are either underestimated or associated to higher volatility classes. The VBS scheme under-predictes the SOA too, but to a lesser

  7. Assessing the impacts of climate change on winter crop production in Uruguay and Argentina using crop simulation models

    Energy Technology Data Exchange (ETDEWEB)

    Baethgen, W.E. [International Fertilizer Development Center, Muscle Shoals, AL (United States); Magrin, G.O. [Inst. Nacional de Tecnologia Agropecuaria Castelar, Buenos Aires (Argentina). Inst. de Clima y Agua

    1995-12-31

    Enhanced greenhouse effect caused by the increase in atmospheric concentration of CO{sub 2} and other trace gases could lead to higher global surface temperature and altered hydrological cycles. Most possible climate change scenarios include higher atmospheric CO{sub 2} concentrations, higher temperatures, and changes in precipitation. Three global climate models (GCMs) were applied to generate climate change scenarios for the Pampas region in southern South America. The generated scenarios were then used with crop simulation models to study the possible impact of climate change on wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) production in the Pampas. The authors evaluated the impact of possible climate change scenarios on wheat and barley production in Uruguay for a wide range of soil and crop management strategies including planting dates, cultivar types, fertilizer management, and tillage practices. They also studied the impact of climate change on wheat production across two transects of the Pampas: north to south transect with decreasing temperature, and east to west transect with decreasing precipitation. Finally, sensitivity analyses were conducted for both, the Uruguayan site and the transects, by increasing daily maximum and minimum temperature by 0, 2, and 4 C, and changing the precipitation by {minus}20, 0, and +20%.

  8. Genome-Wide Association Studies and Comparison of Models and Cross-Validation Strategies for Genomic Prediction of Quality Traits in Advanced Winter Wheat Breeding Lines

    Directory of Open Access Journals (Sweden)

    Peter S. Kristensen

    2018-02-01

    Full Text Available The aim of the this study was to identify SNP markers associated with five important wheat quality traits (grain protein content, Zeleny sedimentation, test weight, thousand-kernel weight, and falling number, and to investigate the predictive abilities of GBLUP and Bayesian Power Lasso models for genomic prediction of these traits. In total, 635 winter wheat lines from two breeding cycles in the Danish plant breeding company Nordic Seed A/S were phenotyped for the quality traits and genotyped for 10,802 SNPs. GWAS were performed using single marker regression and Bayesian Power Lasso models. SNPs with large effects on Zeleny sedimentation were found on chromosome 1B, 1D, and 5D. However, GWAS failed to identify single SNPs with significant effects on the other traits, indicating that these traits were controlled by many QTL with small effects. The predictive abilities of the models for genomic prediction were studied using different cross-validation strategies. Leave-One-Out cross-validations resulted in correlations between observed phenotypes corrected for fixed effects and genomic estimated breeding values of 0.50 for grain protein content, 0.66 for thousand-kernel weight, 0.70 for falling number, 0.71 for test weight, and 0.79 for Zeleny sedimentation. Alternative cross-validations showed that the genetic relationship between lines in training and validation sets had a bigger impact on predictive abilities than the number of lines included in the training set. Using Bayesian Power Lasso instead of GBLUP models, gave similar or slightly higher predictive abilities. Genomic prediction based on all SNPs was more effective than prediction based on few associated SNPs.

  9. Cellular microstructure of chill block melt spun Ni-Mo alloys

    Science.gov (United States)

    Tewari, S. N.; Glasgow, T. K.

    1987-01-01

    Chill block melt spun ribbons of Ni-Mo binary alloys containing 8.0 to 41.8 wt pct Mo have been prepared under carefully controlled processing conditions. The growth velocity has been determined as a function of distance from the quench surface from the observed ribbon thickness dependence on the melt puddle residence time. Primary arm spacings measured at the midribbon thickness locations show a dependence on growth velocity and alloy composition which is expected from dendritic growth models for binary alloys directionally solidified in a positive temperature gradient. Microsegregation across cells and its variation with distance from the quench surface and alloy composition have been examined and compared with theoretical predictions.

  10. Effects of Aesthetic Chills on a Cardiac Signature of Emotionality.

    Directory of Open Access Journals (Sweden)

    Maria Sumpf

    Full Text Available Previous studies have shown that a cardiac signature of emotionality (referred to as EK, which can be computed from the standard 12 lead electrocardiogram, ECG, predicts inter-individual differences in the tendency to experience and express positive emotion. Here, we investigated whether EK values can be transiently modulated during stimulation with participant-selected music pieces and film scenes that elicit strongly positive emotion.The phenomenon of aesthetic chills, as indicated by measurable piloerection on the forearm, was used to accurately locate moments of peak emotional responses during stimulation. From 58 healthy participants, continuous EK values, heart rate, and respiratory frequency were recorded during stimulation with film scenes and music pieces, and were related to the aesthetic chills. EK values, as well as heart rate, increased significantly during moments of peak positive emotion accompanied by piloerection.These results are the first to provide evidence for an influence of momentary psychological state on a cardiac signature of emotional personality (as reflected in EK values. The possibility to modulate ECG amplitude signatures via stimulation with emotionally significant music pieces and film scenes opens up new perspectives for the use of emotional peak experiences in the therapy of disorders characterized by flattened emotionality, such as depression or schizoid personality disorder.

  11. Effects of Aesthetic Chills on a Cardiac Signature of Emotionality.

    Science.gov (United States)

    Sumpf, Maria; Jentschke, Sebastian; Koelsch, Stefan

    2015-01-01

    Previous studies have shown that a cardiac signature of emotionality (referred to as EK, which can be computed from the standard 12 lead electrocardiogram, ECG), predicts inter-individual differences in the tendency to experience and express positive emotion. Here, we investigated whether EK values can be transiently modulated during stimulation with participant-selected music pieces and film scenes that elicit strongly positive emotion. The phenomenon of aesthetic chills, as indicated by measurable piloerection on the forearm, was used to accurately locate moments of peak emotional responses during stimulation. From 58 healthy participants, continuous EK values, heart rate, and respiratory frequency were recorded during stimulation with film scenes and music pieces, and were related to the aesthetic chills. EK values, as well as heart rate, increased significantly during moments of peak positive emotion accompanied by piloerection. These results are the first to provide evidence for an influence of momentary psychological state on a cardiac signature of emotional personality (as reflected in EK values). The possibility to modulate ECG amplitude signatures via stimulation with emotionally significant music pieces and film scenes opens up new perspectives for the use of emotional peak experiences in the therapy of disorders characterized by flattened emotionality, such as depression or schizoid personality disorder.

  12. Chilled beams. A versatile solution; Plafondconvectoren. Trendy en tochtvrij

    Energy Technology Data Exchange (ETDEWEB)

    Svensson, G. [Swegon AB, Tomelila (Sweden)

    2009-04-15

    When carefully selected and installed chilled beams provide a comfortable indoor climate. However, draught should always be avoided. Computer programs for calculating the required cooling and heating capacity are very useful. CFD (computational fluid dynamics) is often used for large and complicated projects in order to predict the air currents, air flow and room temperatures. Chilled beams can flexibly be applied in open offices. Furthermore, they can easily be installed and serviced, and are very energy efficient. [Dutch] Plafondconvectoren zorgen voor een aangenaam en comfortabel binnenklimaat indien de selectie en de situering ervan in de te conditioneren ruimten zorgvuldig wordt uitgevoerd. Tochtverschijnselen moeten echter altijd worden voorkomen. Computerprogramma's voor het berekenen van het benodigde koel- en verwarmingsvermogen zijn hierbij een uitstekend hulpmiddel. Voor grote en complexe projecten wordt vaak gebruikgemaakt van CFD-simulatieprogramma's om de luchtstromen, de luchtsnelheid en de temperaturen van tevoren te kunnen voorspellen. Plafondconvectoren kunnen ook bij open kantoren flexibel worden toegepast. Ze kunnen voor alle toepassingen gemakkelijk worden gemonteerd, zijn onderhoudsvriendelijk en zorgen tevens voor een hoge mate van energie-efficiency.

  13. Kansas environmental and resource study: A Great Plains model. [land use, image enhancement, winter wheat, agriculture, water resources, and pattern recognition

    Science.gov (United States)

    Haralick, R. M.; Kanemasu, E. T.; Morain, S. A.; Yarger, H. L.; Ulaby, F. T.; Davis, J. C. (Principal Investigator); Bosley, R. J.; Williams, D. L.; Mccauley, J. R.; Mcnaughton, J. L.

    1973-01-01

    The author has identified the following significant results. Improvement in the land use classification accuracy of ERTS-1 MSS multi-images over Kansas can be made using two distances between neighboring grey tone N-tuples instead of one distance. Much more information is contained texturally than spectrally on the Kansas image. Ground truth measurements indicate that reflectance ratios of the 545 and 655 nm wavebands provide an index of plant development and possibly physiological stress. Preliminary analysis of MSS 4 and 5 channels substantiate the ground truth interpretation. Results of the land use mapping experiment indicate that ERTS-1 imagery has major potential in regionalization. The ways in which land is utilized within these regions may then be studied more effectively than if no adequate regionalization is available. A model for estimating wheat yield per acre has been applied to acreage estimates derived from ERTS-1 imagery to project the 1973 wheat yields for a ten county area in southwest Kansas. The results are within 3% of the preharvest estimates for the same area prepared by the USDA. Visual identification of winter wheat is readily achieved by using a temporal sequence of images. Identification can be improve by stratifying the project area into subregions having more or less homogeneous agricultural practices and crop mixes.

  14. Wintertime Overnight NOx Removal in a Southeastern United States Coal-Fired Power Plant Plume: A Model for Understanding Winter NOx Processing and Its Implications

    Science.gov (United States)

    Fibiger, Dorothy L.; McDuffie, Erin E.; Dube, William P.; Aikin, Kenneth C.; Lopez-Hilifiker, Felipe D.; Lee, Ben H.; Green, Jaime R.; Fiddler, Marc N.; Holloway, John S.; Ebben, Carlena; hide

    2018-01-01

    Nitric oxide (NO) is emitted in large quantities from coal-�burning power plants. During the day, the plumes from these sources are efficiently mixed into the boundary layer, while at night, they may remain concentrated due to limited vertical mixing during which they undergo horizontal fanning. At night, the degree to which NO is converted to HNO3 and therefore unable to participate in next-�day ozone (O3) formation depends on the mixing rate of the plume, the composition of power plant emissions, and the composition of the background atmosphere. In this study, we use observed plume intercepts from the Wintertime INvestigation of Transport, Emissions and Reactivity (WINTER) campaign to test sensitivity of overnight NOx removal to the N2O5 loss rate constant, plume mixing rate, background O3, and background levels of volatile organic compounds using a 2-�D box model of power plant plume transport and chemistry. The factor that exerted the greatest control over NOx removal was the loss rate constant of N2O5. At the lowest observed N2O5 loss rate constant, no other combination of conditions converts more than 10 percent of the initial NOx to HNO3. The other factors did not influence NOx removal to the same degree.

  15. Modelagem do sistema de resfriamento por imersão de carcaças de frangos utilizando redes neurais artificiais = Modeling of the poultry carcass immersion chilling system using artificial neural networks

    Directory of Open Access Journals (Sweden)

    Túlio Klassen

    2009-04-01

    Full Text Available A modelagem matemática fenomenológica do processo de resfriamento decarcaças de frango em chillers é complexa pela quantidade de variáveis que interferem no processo, além de tratar de um problema que envolve transferência de calor e de massa em regime transeniente. Uma alternativa para modelar este tipo de sistema é o emprego deRedes Neurais Artificiais. Neste trabalho foram investigadas diversas estruturas de redes com uma camada intermediária para modelar o processo de resfriamento de frangos. Foram testadas diferentes arquiteturas alterando os números de neurônios das camadas de entrada e intermediária. Foram utilizados dados coletados na empresa Sadia–Toledo, Estado do Paraná, para treinamento e validação das redes. As variáveis de entrada da rede eram: massa da carcaça, temperatura antes do resfriamento, temperatura da camisa de propilenoglicol,vazão de água em cada módulo, tempo de residência e temperatura da água de renovação; a temperatura do frango na saída do último tanque de resfriamento era a variável de saída. Os resultados obtidos mostraram que as redes representam apropriadamente o processo e que arede com estrutura 8-24-1 foi a que melhor modelou o sistema investigado.The process of cooling chicken carcasses by immersing themin mixture of cold water and ice (chillers is complex. It is very difficult to represent it by a transport phenomenon model. In this work, artificial neural networks were used with an intermediary layer in the description and modeling of the cooling process of chickens.Different architectures of the neural network were tested, altering the numbers of input and hidden units. Data supplied by the Sadia-Toledo Company were used for training and validation of the neural networks. The input variables selected for the model were thefollowing: carcass weight, initial temperature, propylene glycol temperature with external circulation, water flow rate of water in each tank, renewal

  16. Editorial - The winter Atomiades

    CERN Multimedia

    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...

  17. Projecting the impact of climate change on phenology of winter wheat in northern Lithuania.

    Science.gov (United States)

    Juknys, Romualdas; Velička, Rimantas; Kanapickas, Arvydas; Kriaučiūnienė, Zita; Masilionytė, Laura; Vagusevičienė, Ilona; Pupalienė, Rita; Klepeckas, Martynas; Sujetovienė, Gintarė

    2017-10-01

    Climate warming and a shift in the timing of phenological phases, which lead to changes in the duration of the vegetation period may have an essential impact on the productivity of winter crops. The main purpose of this study is to examine climate change-related long-term (1961-2015) changes in the duration of both initial (pre-winter) and main (post-winter) winter wheat vegetation seasons and to present the projection of future phenological changes until the end of this century. Delay and shortening of pre-winter vegetation period, as well as the advancement and slight extension of the post-winter vegetation period, resulted in the reduction of whole winter wheat vegetation period by more than 1 week over the investigated 55 years. Projected changes in the timing of phenological phases which define limits of a main vegetation period differ essentially from the observed period. According to pessimistic (Representative Concentration Pathways 8.5) scenario, the advancement of winter wheat maturity phase by almost 30 days and the shortening of post-winter vegetation season by 15 days are foreseen for a far (2071-2100) projection. An increase in the available chilling amount is specific not only to the investigated historical period (1960-2015) but also to the projected period according to the climate change scenarios of climate warming for all three projection periods. Consequently, the projected climate warming does not pose a threat of plant vernalization shortage in the investigated geographical latitudes.

  18. High-frequency and meso-scale winter sea-ice variability in the Southern Ocean in a high-resolution global ocean model

    Science.gov (United States)

    Stössel, Achim; von Storch, Jin-Song; Notz, Dirk; Haak, Helmuth; Gerdes, Rüdiger

    2018-03-01

    This study is on high-frequency temporal variability (HFV) and meso-scale spatial variability (MSV) of winter sea-ice drift in the Southern Ocean simulated with a global high-resolution (0.1°) sea ice-ocean model. Hourly model output is used to distinguish MSV characteristics via patterns of mean kinetic energy (MKE) and turbulent kinetic energy (TKE) of ice drift, surface currents, and wind stress, and HFV characteristics via time series of raw variables and correlations. We find that (1) along the ice edge, the MSV of ice drift coincides with that of surface currents, in particular such due to ocean eddies; (2) along the coast, the MKE of ice drift is substantially larger than its TKE and coincides with the MKE of wind stress; (3) in the interior of the ice pack, the TKE of ice drift is larger than its MKE, mostly following the TKE pattern of wind stress; (4) the HFV of ice drift is dominated by weather events, and, in the absence of tidal currents, locally and to a much smaller degree by inertial oscillations; (5) along the ice edge, the curl of the ice drift is highly correlated with that of surface currents, mostly reflecting the impact of ocean eddies. Where ocean eddies occur and the ice is relatively thin, ice velocity is characterized by enhanced relative vorticity, largely matching that of surface currents. Along the ice edge, ocean eddies produce distinct ice filaments, the realism of which is largely confirmed by high-resolution satellite passive-microwave data.

  19. Performance of personalized ventilation combined with chilled ceiling in an office room: inhaled air quality and contaminant distribution

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2014-01-01

    people (exhaled air, bioeffluents) and building materials (wall painting). Personalized ventilation combined with chilled ceiling ensured highest air quality at the workstation under all conditions. Pollutant concentration in the occupied zone away from the workstations did not differ substantially...... between the tested systems. Chilled ceiling combined with personalized ventilation working as the only air supplying system may be optimal solution in many buildings.......In a simulated two persons’ office room inhaled air quality and contaminant distribution provided with personalized ventilation combined with chilled ceiling, mixing ventilation only, chilled ceiling with mixing ventilation and chilled ceiling with mixing and personalized ventilation was studied...

  20. Influence of Cooling Conditions on a Slab’s Chill Zone Formation During Continuous Casting of Steel

    Directory of Open Access Journals (Sweden)

    Drożdż P.

    2017-06-01

    Full Text Available The cooling conditions of a slab during continuous casting of steel have an impact on the crystalline structure formation. Numerical methods allow real processes to be modelled. Professional computer programs are available on the market, so the results of their simulations allow us to understand the processes that occur during the casting and solidification of the slab. The study attempts to evaluate the impact of the intensity of the secondary cooling on the chilled zone size. The calculations show the differences in the structure of a slab cast with various speeds while maintaining industrial cooling parameters during operation of a continuous casting machine.

  1. It’s Time to Take the Chill Out of Cost Containment and Re-energize Key Acquisition Practice

    Science.gov (United States)

    2010-05-01

    Lockheed Martin ? ? ? ? ZCORE Cost Oriented Resource  Estimating Model USAF ? ? ? ? ACEIT Automated Cost  Estimating  Integrated  Tools  (USAF, USA...and Logistics) Milestone III chair LCCH Criticisms of high cost, ASD (Acquisition and Logistics) Milestone III chair ACEIT (86 USAF at Hanscom...w/Tecolote Research) ACEIT (86 USAF at Hanscom w/Tecolote Research) ?? It’s Time to Take the Chill Out of Cost Containment and Re-energize a

  2. Effect of ageing time on suckling lamb meat quality resulting from different carcass chilling regimes.

    Science.gov (United States)

    Vieira, C; Fernández, A M

    2014-02-01

    The effect of ageing on suckling lamb carcasses subjected to three chilling treatments was studied: Conventional (2 °C for 24h), ultra-fast (-20 °C for 3.5h then 2 °C until 24h post mortem) and slow chilling (12 °C for 7h then 2 °C until 24h post mortem) treatments. Meat quality measurements were carried out in carcasses at 24h post mortem and also after 5 days of ageing. Carcass chilling losses were not affected by a chilling regime. Aged meat showed higher cooking losses than non-aged meat (p<0.05). Sarcomere length of ultra-fast t was shorter (p<0.05) than conventional and conventional was shorter than slow chilling treatment (p<0.05), at 24h and after 5 days of ageing. Conventional and ultra-fast chilling treatments resulted in higher shear force values at 24h post mortem (p<0.05) compared to slow treatment. All treatments improved sensory scores with ageing (p<0.05), but ultra-fast chilling treatment did not attain higher values as the other two treatments. © 2013.

  3. Two types of peak emotional responses to music: The psychophysiology of chills and tears

    Science.gov (United States)

    Mori, Kazuma; Iwanaga, Makoto

    2017-01-01

    People sometimes experience a strong emotional response to artworks. Previous studies have demonstrated that the peak emotional experience of chills (goose bumps or shivers) when listening to music involves psychophysiological arousal and a rewarding effect. However, many aspects of peak emotion are still not understood. The current research takes a new perspective of peak emotional response of tears (weeping, lump in the throat). A psychophysiological experiment showed that self-reported chills increased electrodermal activity and subjective arousal whereas tears produced slow respiration during heartbeat acceleration, although both chills and tears induced pleasure and deep breathing. A song that induced chills was perceived as being both happy and sad whereas a song that induced tears was perceived as sad. A tear-eliciting song was perceived as calmer than a chill-eliciting song. These results show that tears involve pleasure from sadness and that they are psychophysiologically calming; thus, psychophysiological responses permit the distinction between chills and tears. Because tears may have a cathartic effect, the functional significance of chills and tears seems to be different. We believe that the distinction of two types of peak emotions is theoretically relevant and further study of tears would contribute to more understanding of human peak emotional response. PMID:28387335

  4. Insights into the Molecular Events That Regulate Heat-Induced Chilling Tolerance in Citrus Fruits.

    Science.gov (United States)

    Lafuente, María T; Establés-Ortíz, Beatriz; González-Candelas, Luis

    2017-01-01

    Low non-freezing temperature may cause chilling injury (CI), which is responsible for external quality deterioration in many chilling-sensitive horticultural crops. Exposure of chilling-sensitive citrus cultivars to non-lethal high-temperature conditioning may increase their chilling tolerance. Very little information is available about the molecular events involved in such tolerance. In this work, the molecular events associated with the low temperature tolerance induced by heating Fortune mandarin, which is very sensitive to chilling, for 3 days at 37°C prior to cold storage is presented. A transcriptomic analysis reveals that heat-conditioning has an important impact favoring the repression of genes in cold-stored fruit, and that long-term heat-induced chilling tolerance is an active process that requires activation of transcription factors involved in transcription initiation and of the WRKY family. The analysis also shows that chilling favors degradation processes, which affect lipids and proteins, and that the protective effect of the heat-conditioning treatment is more likely to be related to the repression of the genes involved in lipid degradation than to the modification of fatty acids unsaturation, which affects membrane permeability. Another major factor associated with the beneficial effect of the heat treatment on reducing CI is the regulation of stress-related proteins. Many of the genes that encoded such proteins are involved in secondary metabolism and in oxidative stress-related processes.

  5. Two types of peak emotional responses to music: The psychophysiology of chills and tears.

    Science.gov (United States)

    Mori, Kazuma; Iwanaga, Makoto

    2017-04-07

    People sometimes experience a strong emotional response to artworks. Previous studies have demonstrated that the peak emotional experience of chills (goose bumps or shivers) when listening to music involves psychophysiological arousal and a rewarding effect. However, many aspects of peak emotion are still not understood. The current research takes a new perspective of peak emotional response of tears (weeping, lump in the throat). A psychophysiological experiment showed that self-reported chills increased electrodermal activity and subjective arousal whereas tears produced slow respiration during heartbeat acceleration, although both chills and tears induced pleasure and deep breathing. A song that induced chills was perceived as being both happy and sad whereas a song that induced tears was perceived as sad. A tear-eliciting song was perceived as calmer than a chill-eliciting song. These results show that tears involve pleasure from sadness and that they are psychophysiologically calming; thus, psychophysiological responses permit the distinction between chills and tears. Because tears may have a cathartic effect, the functional significance of chills and tears seems to be different. We believe that the distinction of two types of peak emotions is theoretically relevant and further study of tears would contribute to more understanding of human peak emotional response.

  6. Insights into the Molecular Events That Regulate Heat-Induced Chilling Tolerance in Citrus Fruits

    Directory of Open Access Journals (Sweden)

    María T. Lafuente

    2017-06-01

    Full Text Available Low non-freezing temperature may cause chilling injury (CI, which is responsible for external quality deterioration in many chilling-sensitive horticultural crops. Exposure of chilling-sensitive citrus cultivars to non-lethal high-temperature conditioning may increase their chilling tolerance. Very little information is available about the molecular events involved in such tolerance. In this work, the molecular events associated with the low temperature tolerance induced by heating Fortune mandarin, which is very sensitive to chilling, for 3 days at 37°C prior to cold storage is presented. A transcriptomic analysis reveals that heat-conditioning has an important impact favoring the repression of genes in cold-stored fruit, and that long-term heat-induced chilling tolerance is an active process that requires activation of transcription factors involved in transcription initiation and of the WRKY family. The analysis also shows that chilling favors degradation processes, which affect lipids and proteins, and that the protective effect of the heat-conditioning treatment is more likely to be related to the repression of the genes involved in lipid degradation than to the modification of fatty acids unsaturation, which affects membrane permeability. Another major factor associated with the beneficial effect of the heat treatment on reducing CI is the regulation of stress-related proteins. Many of the genes that encoded such proteins are involved in secondary metabolism and in oxidative stress-related processes.

  7. A chilling sensitive mutant of Arabidopsis with altered steryl-ester metabolism

    International Nuclear Information System (INIS)

    Hugly, S.; McCourt, P.; Somerville, C.; Browse, J.; Patterson, G.W.

    1990-01-01

    A chilling-sensitive mutant of Arabidopsis thaliana was isolated and subjected to genetic, physiological, and biochemical analysis. The chilling-sensitive nature of the mutant line is due to a single recessive nuclear mutation at a locus designated chs1. In contrast to wild-type plants, which are not adversely affected by low temperatures, the chs1 mutant is killed by several days of exposure to temperatures below 18 degree C. Following exposure to chilling temperatures, the mutant displays two common symptoms of chilling injury - leaf chlorosis and electrolyte leakage. In these respects, the physiological response of the mutant to low temperatures mimics the response observed in some naturally occurring chilling sensitive species. The biochemical basis of chilling sensitivity was explored by examining the pattern of incorporation of 14 CO 2 into soluble metabolites and lipids in wild-type and mutant plants. The only difference observed between the mutant and wild type was that following low temperature treatment, the mutant accumulated 10-fold more radioactivity in a specific class of neutral lipids which were identified by a variety of criteria to be steryl-esters. The accumulation of radioactivity in the steryl-ester fraction occurs 24 hours before there is any visible evidence of chilling injury

  8. Physiological and biochemical mechanisms of seed priming-induced chilling tolerance in rice cultivars

    Directory of Open Access Journals (Sweden)

    Saddam eHussain

    2016-02-01

    Full Text Available Rice belongs to tropical and subtropical environments and is extremely sensitive to chilling stress particularly during emergence and early stages of seedling development. Seed priming can be a good approach to enhance rice germination and stand establishment under chilling stress. The present study examined the role of different seed priming techniques viz., hydropriming, osmopriming, redox priming, chemical priming, and hormonal priming, in enhancing the chilling tolerance in rice. The most effective reagents and their pre-optimized concentrations based on preliminary experiments were used in this study. Two different rice cultivars were sown under chilling stress (18˚C and normal temperatures (28˚C in separate growth chambers. A non-primed control treatment was also maintained for comparison. Chilling stress caused erratic and delayed germination, poor seedling growth, reduced starch metabolism and lower respiration rate, while higher lipid peroxidation and hydrogen peroxide accumulation in rice seedlings of both cultivars. Nevertheless, all the seed priming treatments effectively alleviated the negative effects of chilling stress. In addition, seed priming treatments triggered the activities of superoxide dismutase, peroxidase, and catalase, and enhanced the accumulations of glutathione and free proline in rice seedlings, which suggests that these measures help prevent the rice seedlings from chilling induced oxidative stress. Chemical priming with selenium and hormonal priming with salicylic acid remained more effective treatments for both rice cultivars under chilling stress than all other priming treatments. The better performance and greater tolerance of primed rice seedlings was associated with enhanced starch metabolism, high respiration rate, lower lipid peroxidation, and strong antioxidative defense system under chilling stress.

  9. Superchilling of muscle foods: Potential alternative for chilling and freezing.

    Science.gov (United States)

    Banerjee, Rituparna; Maheswarappa, Naveena Basappa

    2017-12-05

    Superchilling is an attractive technique for preservation of muscle foods which freezes part of the water and insulate the food products from temperature fluctuations thereby enhancing the shelf-life during storage, transportation and retailing. Superchilling process synergistically improves the product shelf-life when used in combination with vacuum or modified atmospheric packaging. The shelf-life of muscle foods was reported to be increased by 1.5 to 4.0 times relative to traditional chilling technique. Advantages of superchilling and its ability to maintain the freshness of muscle foods over freezing has been discussed and its potential for Industrial application is highlighted. Present review also unravel the mechanistic bases for ice-crystal formation during superchilling and measures to ameliorate the drip loss. The future challenges especially automation in superchilling process for large scale Industrial application is presented.

  10. Dynamic modeling of stratification for chilled water storage tank

    International Nuclear Information System (INIS)

    Osman, Kahar; Al Khaireed, Syed Muhammad Nasrul; Ariffin, Mohd Kamal; Senawi, Mohd Yusoff

    2008-01-01

    Air conditioning of buildings can be costly and energy consuming. Application of thermal energy storage (TES) reduces cost and energy consumption. The efficiency of the overall operation is affected by storage tank sizing design, which affects thermal stratification of water during charging and discharging processes in TES system. In this study, numerical simulation is used to determine the relationship between tank size and good thermal stratification. Three dimensional simulations with different tank height-to-diameter ratio (HD) and inlet Reynolds number (Re) are investigated. The effect of the number of diffuser holes is also studied. For shallow tanks (low HD) simulations, no acceptable thermocline thickness can be seen for all Re experimented. Partial mixing is observed throughout the process. Medium HD tanks simulations show good thermocline behavior and clear distinction between warm and cold water can be seen. Finally, deep tanks (high HD) show less acceptable thermocline thickness as compared to that of medium HD tanks. From this study, doubling and halving the number of diffuser holes show no significant effect on the thermocline behavior

  11. Winter Frost and Fog

    Science.gov (United States)

    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

  12. Modelling winter organic aerosol at the European scale with CAMx: evaluation and source apportionment with a VBS parameterization based on novel wood burning smog chamber experiments

    Science.gov (United States)

    Ciarelli, Giancarlo; Aksoyoglu, Sebnem; El Haddad, Imad; Bruns, Emily A.; Crippa, Monica; Poulain, Laurent; Äijälä, Mikko; Carbone, Samara; Freney, Evelyn; O'Dowd, Colin; Baltensperger, Urs; Prévôt, André S. H.

    2017-06-01

    We evaluated a modified VBS (volatility basis set) scheme to treat biomass-burning-like organic aerosol (BBOA) implemented in CAMx (Comprehensive Air Quality Model with extensions). The updated scheme was parameterized with novel wood combustion smog chamber experiments using a hybrid VBS framework which accounts for a mixture of wood burning organic aerosol precursors and their further functionalization and fragmentation in the atmosphere. The new scheme was evaluated for one of the winter EMEP intensive campaigns (February-March 2009) against aerosol mass spectrometer (AMS) measurements performed at 11 sites in Europe. We found a considerable improvement for the modelled organic aerosol (OA) mass compared to our previous model application with the mean fractional bias (MFB) reduced from -61 to -29 %. We performed model-based source apportionment studies and compared results against positive matrix factorization (PMF) analysis performed on OA AMS data. Both model and observations suggest that OA was mainly of secondary origin at almost all sites. Modelled secondary organic aerosol (SOA) contributions to total OA varied from 32 to 88 % (with an average contribution of 62 %) and absolute concentrations were generally under-predicted. Modelled primary hydrocarbon-like organic aerosol (HOA) and primary biomass-burning-like aerosol (BBPOA) fractions contributed to a lesser extent (HOA from 3 to 30 %, and BBPOA from 1 to 39 %) with average contributions of 13 and 25 %, respectively. Modelled BBPOA fractions were found to represent 12 to 64 % of the total residential-heating-related OA, with increasing contributions at stations located in the northern part of the domain. Source apportionment studies were performed to assess the contribution of residential and non-residential combustion precursors to the total SOA. Non-residential combustion and road transportation sector contributed about 30-40 % to SOA formation (with increasing contributions at urban and near

  13. Application of TRMM PR and TMI Measurements to Assess Cloud Microphysical Schemes in the MM5 Model for a Winter Storm

    Science.gov (United States)

    Han, Mei; Braun, Scott A.; Olson, William S.; Persson, P. Ola G.; Bao, Jian-Wen

    2009-01-01

    . This study employs this method to evaluate the accuracy of the simulated radiative properties by the MM5 model with different microphysical schemes. It is found that the representations of particle density, size, and mass in the different schemes in the MM5 model determine the model s performance when predicting a winter storm over the eastern Pacific Ocean. Schemes lacking moderate density particles (i.e. graupel), with snow flakes that are too large, or with excessive mass of snow or graupel lead to degraded prediction of the radiative properties as observed by the TRMM satellite. This study demonstrates the uniqueness of the combination of both an active microwave sensor (PR) and passive microwave sensor (TMI) onboard TRMM on assessing the accuracy of numerical weather forecasting. It improves our understanding of the physical and radiative properties of different types of precipitation particles and provides suggestions for better representation of cloud and precipitation processes in numerical models. It would, ultimately, contribute to answering questions like "Why did it not rain when the forecast says it would?"

  14. Mortality impact of extreme winter temperatures

    Science.gov (United States)

    Díaz, Julio; García, Ricardo; López, César; Linares, Cristina; Tobías, Aurelio; Prieto, Luis

    2005-01-01

    During the last few years great attention has been paid to the evaluation of the impact of extreme temperatures on human health. This paper examines the effect of extreme winter temperature on mortality in Madrid for people older than 65, using ARIMA and GAM models. Data correspond to 1,815 winter days over the period 1986 1997, during which time a total of 133,000 deaths occurred. The daily maximum temperature (Tmax) was shown to be the best thermal indicator of the impact of climate on mortality. When total mortality was considered, the maximum impact occured 7 8 days after a temperature extreme; for circulatory diseases the lag was between 7 and 14 days. When respiratory causes were considered, two mortality peaks were evident at 4 5 and 11 days. When the impact of winter extreme temperatures was compared with that associated with summer extremes, it was found to occur over a longer term, and appeared to be more indirect.

  15. Decontamination and winter conditions

    International Nuclear Information System (INIS)

    Quenild, C.; Tveten, U.

    1984-12-01

    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

  16. Spirit's Winter Work Site

    Science.gov (United States)

    2006-01-01

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

  17. Winter School Les Houches

    CERN Document Server

    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...

  18. The chills as a psychological construct: content universe, factor structure, affective composition, elicitors, trait antecedents, and consequences.

    Science.gov (United States)

    Maruskin, Laura A; Thrash, Todd M; Elliot, Andrew J

    2012-07-01

    We examined the content universe, factor structure, affective composition, elicitors, trait antecedents, and consequences of "the chills." In Study 1, participants described what it means to get the chills. A second sample sorted all references to physical sensations based on similarity. Cluster analysis identified 4 lower order clusters (goosebumps, tingling, coldness, shivers) and 2 higher order clusters ("goosetingles," "coldshivers"). In Study 2, factor analysis of questionnaire data supported a model with lower and higher order factors that corresponded to the Study 1 clusters. Goosetingles and coldshivers were predicted by approach-related traits (e.g., extraversion) and avoidance-related traits (e.g., neuroticism), respectively. In Study 3, analysis of narrative data replicated the goosetingles-coldshivers structure. Relative to coldshivers, goosetingles involved greater awe, surprise, and enjoyment and less disgust, fear, and sadness. In Study 4, analysis of diary data extended the goosetingles-coldshivers structure to between- and within-person levels of analysis. Goosetingles involved positive affects and was elicited by approach-related stimuli, whereas coldshivers involved negative affects and was elicited by avoidance-related stimuli. In Study 5, manipulation of exposure to self-actualization and self-annihilation elicited goosetingles and coldshivers, respectively. Goosetingles and coldshivers had positive and negative effects, respectively, on interpersonal closeness. In sum, diverse forms of evidence converge to indicate that the chills encompasses distinct approach- and avoidance-related constructs. Failure to distinguish these constructs explains null and inconsistent findings in the nascent literature. Goosetingles and coldshivers are posited to serve the function of signaling that an event in the environment is pertinent to one's most deep-seated hopes or fears. PsycINFO Database Record (c) 2012 APA, all rights reserved

  19. Assessing climate change impacts on winter cover crop nitrate uptake efficiency on the coastal plain of the Chesapeake Bay watershed using the SWAT model

    Science.gov (United States)

    Climate change is expected to exacerbate water quality degradation in the Chesapeake Bay watershed (CBW). Winter cover crops (WCCs) have been widely implemented in this region owing to their high effectiveness at reducing nitrate loads. However, little is known about climate change impacts on the ef...

  20. Assessing the impacts of future climate conditions on the effectiveness of winter cover crops in reducing nitrate loads into the Chesapeake Bay Watersheds using SWAT model

    Science.gov (United States)

    Winter cover crops (WCCs) have been widely implemented in the Coastal Plain of the Chesapeake Bay watershed (CBW) due to their high effectiveness at reducing nitrate loads. However, future climate conditions (FCCs) are expected to exacerbate water quality degradation in the CBW by increasing nitrat...

  1. Aesthetic chills: Knowledge-acquisition, meaning-making and aesthetic emotions

    Directory of Open Access Journals (Sweden)

    Leonid Perlovsky

    2016-08-01

    Full Text Available This article addresses the relation between aesthetic emotions, knowledge-acquisition, and meaning-making. We briefly review theoretical foundations and present experimental data related to aesthetic chills. These results suggest that aesthetic chills are inhibited by exposing the subject to an incoherent prime prior to the chill-eliciting stimulation, and that a meaningful prime makes the aesthetic experience more pleasurable than a neutral or an incoherent one. Aesthetic chills induced by narrative structures seem to be related to the pinnacle of the story, to have a significant calming effect and subjects describe a strong empathy for the characters. We discuss the relation between meaning-making and aesthetic emotions at the psychological, physiological, narratological, and mathematical levels and propose a series of hypotheses to be tested in future research.

  2. Process for nondestructively testing with radioactive gas using a chill set sealant

    International Nuclear Information System (INIS)

    Gibbons, C.B.

    1975-01-01

    An article surface is nondestructively tested for substantially invisible surface voids by absorbing a radioactive gas thereon. The adsorbed radioactive gas is disproportionately retained on those surfaces presented by the substantially invisible surface voids as compared to the remaining surfaces of the article contacted by the radioactive gas. The radiation released by the radioactive gas remaining adsorbed is used to identify the substantially invisible voids. To immobilize the radioactive gas adjacent or within the surface voids, a sealant composition is provided which is capable of being chill set. The temperatures of the article surface to be tested and the sealant composition are then related so that the article surface is at a temperature below the chill set temperature of the sealant composition and the sealant composition is at a temperature above its chill set temperature. The article portion to be tested is then coated with sealant composition to form a chill set coating thereon of substantially uniform thickness. (U.S.)

  3. Neutrino oscillation provides clues to dark matter and signals from the chilled universe

    CERN Multimedia

    2006-01-01

    The new verification that oscillations exists and neutrinos have mass though not detectible easy provides the first clue to extra dimensions, dark matter, hyperspace and chilled universe acting as a platform below it. (1/2 page)

  4. GENERAL ALGORITHMIC SCHEMA OF THE PROCESS OF THE CHILL AUXILIARIES PROJECTION

    Directory of Open Access Journals (Sweden)

    A. N. Chichko

    2006-01-01

    Full Text Available The general algorithmic diagram of systematization of the existing approaches to the process of projection is offered and the foundation of computer system of the chill mold arming construction is laid.

  5. Human response to individually controlled micro environment generated with localized chilled beam

    DEFF Research Database (Denmark)

    Uth, Simon C.; Nygaard, Linette; Bolashikov, Zhecho Dimitrov

    2014-01-01

    Indoor environment in a single-office room created by a localised chilled beam with individual control of the primary air flow was studied. Response of 24 human subjects when exposed to the environment generated by the chilled beam was collected via questionnaires under a 2-hour exposure including...... and local thermal sensation reported by the subjects with the two systems. Both systems were equally acceptable. At 26°C the individual control of the localised chilled beam lead to higher acceptability of the work environment. At 28°C the acceptability decreased with the two systems. It was not acceptable...... different work tasks at three locations in the room. Response of the subjects to the environment generated with a chilled ceiling combined with mixing air distribution was used for comparison. The air temperature in the room was kept at 26 or 28 °C. Results show no significant difference in the overall...

  6. Dormancy release and flowering time in Ziziphus jujuba Mill., a "direct flowering" fruit tree, has a facultative requirement for chilling.

    Science.gov (United States)

    Meir, Michal; Ransbotyn, Vanessa; Raveh, Eran; Barak, Simon; Tel-Zur, Noemi; Zaccai, Michele

    2016-03-15

    In deciduous fruit trees, the effect of chilling on flowering has mostly been investigated in the "indirect flowering" group, characterized by a period of rest between flower bud formation and blooming. In the present study, we explored the effects of chilling and chilling deprivation on the flowering of Ziziphus jujuba, a temperate deciduous fruit tree belonging to the "direct flowering" group, in which flower bud differentiation, blooming and fruit development occur after dormancy release, during a single growing season. Dormancy release, vegetative growth and flowering time in Z. jujuba cv. Ben-Li were assessed following several treatments of chilling. Chilling treatments quantitatively decreased the timing of vegetative bud dormancy release, thereby accelerating flowering, but had no effect on the time from dormancy release to flowering. Trees grown at a constant temperature of 25°C, without chilling, broke dormancy and flowered, indicating the facultative character of chilling in this species. We measured the expression of Z. jujuba LFY and AP1 homologues (ZjLFY and ZjAP1). Chilling decreased ZjLFY expression in dormant vegetative buds but had no effect on ZjAP1expression, which reached peak expression before dormancy release and at anthesis. In conclusion, chilling is not obligatory for dormancy release of Z. jujuba cv. Ben-Li vegetative buds. However, the exposure to chilling during dormancy does accelerate vegetative bud dormancy release and flowering. Copyright © 2016 Elsevier GmbH. All rights reserved.

  7. Water Status Related Root-to-Shoot Communication Regulates the Chilling Tolerance of Shoot in Cucumber (Cucumis sativus L.) Plants.

    Science.gov (United States)

    Zhang, Zi-Shan; Liu, Mei-Jun; Gao, Hui-Yuan; Jin, Li-Qiao; Li, Yu-Ting; Li, Qing-Ming; Ai, Xi-Zhen

    2015-10-16

    Although root-to-shoot communication has been intensively investigated in plants under drought, few studies have examined root-to-shoot communication under chilling. Here we explored whether root-to-shoot communication contributes to the chilling-light tolerance of cucumber shoots and clarified the key signal involves in this communication. After leaf discs chilling-light treatment, the photoinhibitions of Photosystem I (PSI) and Photosystem II (PSII) were similar in leaf discs of two cucumber varieties (JY-3 and JC-4). When the whole plants, including roots, were chilled under light, the photosynthetic performances in JC-4 leaves decreased more seriously than that in JY-3 leaves. However, when the water status of leaves was maintained by warming roots or floating the attached leaves on water, the PSII activity and amount of PSI in the leaves of the two varieties were similar after chilling-light treatment. In addition, the differences of PSII activities and amount of PSI between the two varieties under whole plant chilling-light treatment were independent of ABA pretreatment. Above results indicate that (1) the better water status in leaves under chilling contributes to the higher chilling tolerance of JY-3; (2) the water status, rather than an ABA signal, dominates root-to-shoot communication under chilling and the chilling tolerance of cucumber shoot.

  8. Spirit Scans Winter Haven

    Science.gov (United States)

    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.

  9. Winter fuels report

    International Nuclear Information System (INIS)

    1995-01-01

    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

  10. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Impact of Methyl Jasmonate on Enhancing Chilling Tolerance of Cucumber (Cucumis sativus L. Seedlings

    Directory of Open Access Journals (Sweden)

    F. Saydpour

    2016-12-01

    Full Text Available Cucumber is a warm season crop that suffers from chilling injury at temperatures below 10°C. In recent years, jasmonates have been used for reduction of chilling injuries in plants. An experiment was, therefore, conducted to test whether methyl jasmonate (MeJA application at various concentrations (0, 0.05, 0.1 and 0.15 mM through seed soaking or foliar spray would protect cucumber seedlings, subjected to chilling stress. Results showed that MeJA application decreased chilling index, ion leakage, malondialdehyde content and hydrogen peroxide free radical and increased growth parameters, proline contents, chlorophylls contents and antioxidant activity. Although, seed soaking method provided better protection compared to foliar spray method, the highest cold tolerance was obtained with 0.15mM MeJA application in both application methods that caused low level of chilling index (1.67, malondialdehyde content (0.11 nm g-1 FW, hydrogen peroxide free radical (0.22 nm g-1 FW and ion leakage (32.87%. In general, it may be concluded that MeJA could be used effectively to protect cucumber seedling from damaging effects of chilling stress at the early stages of growth.

  12. Effects of watertable and fertilizer management on susceptibility of tomato fruit to chilling injury

    International Nuclear Information System (INIS)

    Dodds, G.T.; Trenholm, L.; Madramootoo, C.A.

    1996-01-01

    In a 2-year study (1993-1994), 'New Yorker' tomato (Lycopersicon esculentum Mill.) plants grown in field lysimeters were subjected to four water table depth (WTD) treatments (0.3, 0.6, 0.8, and 1.0 m from the soil surface) factorially combined with 5 potassium/calcium fertilization combinations. Mature-green fruit from four replicates of each treatment were stored at 5C for 21 days, and fruit color was monitored with a tristimulus colorimeter. Fruit were subsequently allowed to ripen at 20C for 10 days, at which time chilling injury was assessed on the basis of delayed ripening and area of lesions. Potassium and calcium applied in the field had no effect on chilling tolerance of the fruit. In the drier year (1993), shallower WTD treatments generally yielded fruit that changed color less during chilling and were more chilling-sensitive based on delayed ripening. In the wetter year, differences in color change and chilling tolerance between WTD, if any, were small. Over both years, lesion area varied with WTD, but not in a consistent manner. Based on these results, we suggest that differences in water availability should be considered when studying tomato fruit chilling

  13. Aquifer thermal-energy-storage costs with a seasonal-chill source

    Science.gov (United States)

    Brown, D. R.

    1983-01-01

    The cost of energy supplied by an aquifer thermal energy storage (ATES) ystem from a seasonal chill source was investigated. Costs were estimated for point demand and residential development ATES systems using the computer code AQUASTOR. AQUASTOR was developed at PNL specifically for the economic analysis of ATES systems. In this analysis the cost effect of varying a wide range of technical and economic parameters was examined. Those parameters exhibiting a substantial influence on the costs of ATES delivered chill were: system size; well flow rate; transmission distance; source temperature; well depth; and cost of capital. The effects of each parameter are discussed. Two primary constraints of ATES chill systems are the extremely low energy density of the storage fluid and the prohibitive costs of lengthly pipelines for delivering chill to residential users. This economic analysis concludes that ATES-delivered chill will not be competitive for residential cooling applications. The otherwise marginal attractiveness of ATES chill systems vanishes under the extremely low load factors characteristic of residential cooling systems. (LCL)

  14. Effects of watertable and fertilizer management on susceptibility of tomato fruit to chilling injury

    Energy Technology Data Exchange (ETDEWEB)

    Dodds, G. T. [McGill University, Sainte Anne-de-Bellevue, Que. (Canada); Trenholm, L.; Madramootoo, C. A.

    1996-05-15

    In a 2-year study (1993-1994), 'New Yorker' tomato (Lycopersicon esculentum Mill.) plants grown in field lysimeters were subjected to four water table depth (WTD) treatments (0.3, 0.6, 0.8, and 1.0 m from the soil surface) factorially combined with 5 potassium/calcium fertilization combinations. Mature-green fruit from four replicates of each treatment were stored at 5C for 21 days, and fruit color was monitored with a tristimulus colorimeter. Fruit were subsequently allowed to ripen at 20C for 10 days, at which time chilling injury was assessed on the basis of delayed ripening and area of lesions. Potassium and calcium applied in the field had no effect on chilling tolerance of the fruit. In the drier year (1993), shallower WTD treatments generally yielded fruit that changed color less during chilling and were more chilling-sensitive based on delayed ripening. In the wetter year, differences in color change and chilling tolerance between WTD, if any, were small. Over both years, lesion area varied with WTD, but not in a consistent manner. Based on these results, we suggest that differences in water availability should be considered when studying tomato fruit chilling.

  15. Microstructure of gross chill-mark defect in a glass-ceramic preform

    International Nuclear Information System (INIS)

    Spears, R.K.

    1980-01-01

    The microstructure of a vacuum tube glass-ceramic preform containing gross chill-marks on the top and bottom surfaces as well as on the sides was analyzed. The preform was ceramed in a graphite mold and examined using SEM. The glass-ceramic had an extremely dense and fine crystalline structure except where the chill-marks were located. In those areas of matrix glass following the chill-mark plane were evident. It is concluded that gross chill-marks will affect the microstructure by disrupting the chemistry or nucleating characteristics in such a way that a chill-mark regon would appear to be depleted of crystallites. Although the crystallites in this region are larger, the quantity is lower than in the base glass-ceramic. The affected area caused by the chill-mark left a band of matrix glass approximately 100 μ wide. It is believed that planar defects of this size will degrade the mechanical and permeation properties of the glass-ceramic

  16. Validation of AquaCrop Model for Simulation of Winter Wheat Yield and Water Use Efficiency under Simultaneous Salinity and Water Stress

    Directory of Open Access Journals (Sweden)

    M. Mohammadi

    2016-02-01

    simulation of soil salinity. In general, the model accuracy for simulation yield and WP was better than simulation of biomass. The d (index of agreement values were very close to one for both varieties, which means that simulated reduction in grain yield and biomass was similar to those of measured ones. In most cases the R2 values were about one, confirming a good correlation between simulated and measured values. The NRMSE values in most cases were lower than 10% which seems to be good. The CRM values were close to zero (under- and over-estimation were negligible. Based on higher WP under deficit irrigation treatments (e.g. I3 compared to full irrigation treatments (e.g. I1 and I2, it seems logical to adopt I3 treatment, especially in Birjand as a water-short region, assigning the remaining 25% to another piece of land. By such strategy, WP would be optimized at the regional scale. Conclusion: The AquaCrop was separately and simultaneously nested calibrated and validated for all salinity treatments. The model accuracy under simultaneous case was slightly lower than that for separate case. According to the results, if the model is well calibrated for minimum and maximum irrigation treatments (full irrigation and maximum deficit irrigation, it could simulate grain yield for any other irrigation treatment in between these two limits. Adopting this approach may reduce the cost of field studies for calibrating the model, since only two irrigation treatments should be conducted in the field. AquaCrop model can be a valuable tool for modelling winter wheat grain yield, WP and biomass. The simplicity of AquaCrop, as it is less data dependent, made it to be user-friendly. Nevertheless, the performance of the model has to be evaluated, validated and fine-tuned under a wider range of conditions and crops. Keywords: Biomass, Plant modeling, Sensitivity analysis

  17. Winter NH low-frequency variability in a hierarchy of low-order stochastic dynamical models of earth-atmosphere system

    Science.gov (United States)

    Zhao, Nan

    2018-02-01

    The origin of winter Northern Hemispheric low-frequency variability (hereafter, LFV) is regarded to be related to the coupled earth-atmosphere system characterized by the interaction of the jet stream with mid-latitude mountain ranges. On the other hand, observed LFV usually appears as transitions among multiple planetary-scale flow regimes of Northern Hemisphere like NAO + , AO +, AO - and NAO - . Moreover, the interaction between synoptic-scale eddies and the planetary-scale disturbance is also inevitable in the origin of LFV. These raise a question regarding how to incorporate all these aspects into just one framework to demonstrate (1) a planetary-scale dynamics of interaction of the jet stream with mid-latitude mountain ranges can really produce LFV, (2) such a dynamics can be responsible for the existence of above multiple flow regimes, and (3) the role of interaction with eddy is also clarified. For this purpose, a hierarchy of low-order stochastic dynamical models of the coupled earth-atmosphere system derived empirically from different timescale ranges of indices of Arctic Oscillation (AO), North Atlantic Oscillation (NAO), Pacific/North American (PNA), and length of day (LOD) and related probability density function (PDF) analysis are employed in this study. The results seem to suggest that the origin of LFV cannot be understood completely within the planetary-scale dynamics of the interaction of the jet stream with mid-latitude mountain ranges, because (1) the existence of multiple flow regimes such as NAO+, AO+, AO- and NAO- resulted from processes with timescales much longer than LFV itself, which may have underlying dynamics other than topography-jet stream interaction, and (2) we find LFV seems not necessarily to come directly from the planetary-scale dynamics of the interaction of the jet stream with mid-latitude mountain, although it can produce similar oscillatory behavior. The feedback/forcing of synoptic-scale eddies on the planetary

  18. Establishment and verification of solar radiation calculation model of glass daylighting roof in hot summer and warm winter zone in China

    OpenAIRE

    Zheng, Caidan; Wu, Peihao; Costanzo, Vincenzo; Wang, Yuchen; Yang, Xiaokun

    2017-01-01

    In this paper, solar heat gain through glass daylighting roof is deeply studied by theoretical calculation method, taking Guangzhou in the Hot Summer and Warm Winter (HSWW) zone as an example. The direct solar radiation is calculated by Bouguer formula whereas the diffuse solar radiation is calculated by Berlage formula, representing the basis for the calculation method of the solar radiation intensity through the glass daylighting roof. Through the establishment of solar radiation calculatio...

  19. The effects of chilling stress after anthesis on the physicochemical properties of rice (Oryza sativa L) starch.

    Science.gov (United States)

    Zhu, Dawei; Wei, Haiyan; Guo, Baowei; Dai, Qigen; Wei, Cunxu; Gao, Hui; Hu, Yajie; Cui, Peiyuan; Li, Min; Huo, Zhongyang; Xu, Ke; Zhang, Hongcheng

    2017-12-15

    This study investigates the effect of chilling stress, over a period of three days after anthesis, on the physicochemical properties of starches derived from six rice cultivars. Chilling stress significantly affected the grain characteristics and physicochemical properties of rice starches, except for those of two varieties, NJ 9108 and ZD 18. In the other four rice cultivars subjected to chilling stress, the content of medium, and large sized granules showed a decrease, and an increase, respectively. Amylose content increased as a result of chilling stress, thereby resulting in starch with a lower swelling power, water solubility, and higher retrogradation enthalpy and gelatinization temperature. Chilling stress led to deterioration of cooked rice quality as determined by the pasting properties of starch. This study indicated that among the cultivars studied, the two rice varieties most resistant to chilling stress after rice anthesis were NJ 9108 and ZD 18. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Impact of broiler processing scalding and chilling profiles on carcass and breast meat yield.

    Science.gov (United States)

    Buhr, R J; Walker, J M; Bourassa, D V; Caudill, A B; Kiepper, B H; Zhuang, H

    2014-06-01

    The effect of scalding and chilling procedures was evaluated on carcass and breast meat weight and yield in broilers. On 4 separate weeks (trials), broilers were subjected to feed withdrawal, weighed, and then stunned and bled in 4 sequential batches (n = 16 broilers/batch, 64 broilers/trial). In addition, breast skin was collected before scalding, after scalding, and after defeathering for proximate analysis. Each batch of 16 carcasses was subjected to either hard (60.0°C for 1.5 min) or soft (52.8°C for 3 min) immersion scalding. Following defeathering and evisceration, 8 carcasses/batch were air-chilled (0.5°C, 120 min, 86% RH) and 8 carcasses/batch were immersion water-chilled (water and ice 0.5°C, 40 min). Carcasses were reweighed individually following evisceration and following chilling. Breast meat was removed from the carcass and weighed within 4 h postmortem. There were significant (P defeathered eviscerated weights did not differ between the scalding and chilling treatments. During air-chilling all carcasses lost weight, resulting in postchill carcass yield of 73.0% for soft-scalded and 71.3% for hard-scalded carcasses, a difference of 1.7%. During water-chilling all carcasses gained weight, resulting in heavier postchill carcass weights (2,031 g) than for air-chilled carcasses (1,899 g). Postchill carcass yields were correspondingly higher for water-chilled carcasses, 78.2% for soft-scalded and 76.1% for hard-scalded carcasses, a difference of 2.1%. Only in trials 1 and 4 was breast meat yield significantly lower for hard-scalded, air-chilled carcasses (16.1 and 17.5%) than the other treatments. Proximate analysis of skin sampled after scalding or defeathering did not differ significantly in moisture (P = 0.2530) or lipid (P = 0.6412) content compared with skin sampled before scalding. Skin protein content was significantly higher (P defeathering. The hard-scalding method used in this experiment did not result in increased skin lipid loss either

  1. Effects of dormancy progression and low-temperature response on changes in the sorbitol concentration in xylem sap of Japanese pear during winter season.

    Science.gov (United States)

    Ito, Akiko; Sugiura, Toshihiko; Sakamoto, Daisuke; Moriguchi, Takaya

    2013-04-01

    In order to elucidate which physiological event(s) are involved in the seasonal changes of carbohydrate dynamics during winter, we examined the effects of different low temperatures on the carbohydrate concentrations of Japanese pear (Pyrus pyrifolia (Burm.) Nakai). For four winter seasons, large increases in the sorbitol concentration of shoot xylem sap occurred during mid- to late December, possibly due to the endodormancy completion and low-temperature responses. When trees were kept at 15 °C from 3 November to 3 December in order to postpone the initiation and completion of chilling accumulation that would break endodormancy, sorbitol accumulation in xylem sap was always higher from trees with sufficient chilling accumulation than from trees that received insufficient chilling. However, an additional increase in xylem sap sorbitol occurred around late December in trees regardless of whether their chilling accumulation naturally progressed or was postponed. To examine different temperature effects more closely, we compared the carbohydrate concentrations of trees subjected to either 6 or 0 °C treatment. The sorbitol concentration in xylem sap tremendously increased at 0 °C treatment compared with 6 °C treatment. However, an additional increase in xylem sap sorbitol occurred at both the temperatures when sufficient chilling accumulated with a peak coinciding with the peak expression in shoots of the sorbitol transporter gene (PpSOT2). Interestingly, the total carbohydrate concentration of shoots tremendously increased with exposure to 0 °C compared with exposure to 6 °C, but was not affected by the amount of accumulated chilling. Instead, as chilling accumulated the ratio of sorbitol to total soluble sugars in shoots increased. We presumed that carbohydrates in the shoot tissues may be converted to sorbitol and loaded into the xylem sap so that the sorbitol accumulation patterns were synchronized with the progression of dormancy, whereas the total

  2. Start of the big chill for the LHC

    CERN Document Server

    2007-01-01

    The cooling of Sector 7-8 of the LHC, the first to undergo the process, is under way to the 1.9 K necessary for superconductivity. During the night of 14 to 15 March, an important milestone was reached when the entire sector was cooled to 4.5 K, the temperature of liquid helium. The two graphs above show the progression of cooling in Sector 7-8. The first gives the status of the sector on Tuesday 6 March at 4:00 pm, the second on Wednesday 7 March at 10:00 am. Each square represents a magnet.It's the start of the big chill for the LHC. Since the middle of January, the teams from the Accelerator Cryogenics group have been working to cool down the first sector of the machine. Three kilometres of magnets between Point 7 (Ferney-Voltaire) and Point 8 (Prévessin) are to be cooled to 1.9 Kelvin (-271°C), colder than outer space. The first step in the process was to cool the sector to 80 K. Following mechanical and electrical integrity tests at this temperature, it was then further cooled to 20 K for additional e...

  3. The chilling effect: how do researchers react to controversy?

    Directory of Open Access Journals (Sweden)

    Joanna Kempner

    2008-11-01

    Full Text Available BACKGROUND: Can political controversy have a "chilling effect" on the production of new science? This is a timely concern, given how often American politicians are accused of undermining science for political purposes. Yet little is known about how scientists react to these kinds of controversies. METHODS AND FINDINGS: Drawing on interview (n = 30 and survey data (n = 82, this study examines the reactions of scientists whose National Institutes of Health (NIH-funded grants were implicated in a highly publicized political controversy. Critics charged that these grants were "a waste of taxpayer money." The NIH defended each grant and no funding was rescinded. Nevertheless, this study finds that many of the scientists whose grants were criticized now engage in self-censorship. About half of the sample said that they now remove potentially controversial words from their grant and a quarter reported eliminating entire topics from their research agendas. Four researchers reportedly chose to move into more secure positions entirely, either outside academia or in jobs that guaranteed salaries. About 10% of the group reported that this controversy strengthened their commitment to complete their research and disseminate it widely. CONCLUSIONS: These findings provide evidence that political controversies can shape what scientists choose to study. Debates about the politics of science usually focus on the direct suppression, distortion, and manipulation of scientific results. This study suggests that scholars must also examine how scientists may self-censor in response to political events.

  4. The Chilling Effect: How Do Researchers React to Controversy?

    Science.gov (United States)

    Kempner, Joanna

    2008-01-01

    Background Can political controversy have a “chilling effect” on the production of new science? This is a timely concern, given how often American politicians are accused of undermining science for political purposes. Yet little is known about how scientists react to these kinds of controversies. Methods and Findings Drawing on interview (n = 30) and survey data (n = 82), this study examines the reactions of scientists whose National Institutes of Health (NIH)-funded grants were implicated in a highly publicized political controversy. Critics charged that these grants were “a waste of taxpayer money.” The NIH defended each grant and no funding was rescinded. Nevertheless, this study finds that many of the scientists whose grants were criticized now engage in self-censorship. About half of the sample said that they now remove potentially controversial words from their grant and a quarter reported eliminating entire topics from their research agendas. Four researchers reportedly chose to move into more secure positions entirely, either outside academia or in jobs that guaranteed salaries. About 10% of the group reported that this controversy strengthened their commitment to complete their research and disseminate it widely. Conclusions These findings provide evidence that political controversies can shape what scientists choose to study. Debates about the politics of science usually focus on the direct suppression, distortion, and manipulation of scientific results. This study suggests that scholars must also examine how scientists may self-censor in response to political events. PMID:19018657

  5. Use of methanol as cryoprotectant and its effect on sox genes and proteins in chilled zebrafish embryos.

    Science.gov (United States)

    Desai, Kunjan; Spikings, Emma; Zhang, Tiantian

    2015-08-01

    Methanol is a widely used cryoprotectant (CPA) in cryopreservation of fish embryos, however little is known about its effect at the molecular level. This study investigated the effect of methanol on sox gene and protein expression in zebrafish embryos (50% epiboly) when they were chilled for 3 h and subsequently warmed and cultured to the hatching stages. Initial experiments were carried out to evaluate the chilling tolerance of 50% epiboly embryos which showed no significant differences in hatching rates for up to 6 h chilling in methanol (0.2-, 0.5- and 1 M). Subsequent experiments in embryos that had been chilled for 3 h in 1 M methanol and warmed and cultured up to the hatching stages found that sox2 and sox3 gene expression were increased significantly in hatched embryos that had been chilled compared to non-chilled controls. Sox19a gene expression also remained above control levels in the chilled embryos at all developmental stages tested. Whilst stable sox2 protein expression was observed between non-chilled controls and embryos chilled for 3 h with or without MeOH, a surge in sox19a protein expression was observed in embryos chilled for 3 h in the presence of 1 M MeOH compared to non-chilled controls and then returned to control levels by the hatching stage. The protective effect of MeOH was increased with increasing concentrations. Effect of methanol at molecular level during chilling was reported here first time which could add new parameter in selection of cryoprotectant while designing cryopreservation protocol. Copyright © 2015. Published by Elsevier Inc.

  6. Winter climate limits subantarctic low forest growth and establishment.

    Directory of Open Access Journals (Sweden)

    Melanie A Harsch

    Full Text Available Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E is oceanic (Conrad Index of Continentality  =  -5 with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C, dry winters (total winter precipitation <400 mm. Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

  7. Winter Climate Limits Subantarctic Low Forest Growth and Establishment

    Science.gov (United States)

    Harsch, Melanie A.; McGlone, Matt S.; Wilmshurst, Janet M.

    2014-01-01

    Campbell Island, an isolated island 600 km south of New Zealand mainland (52°S, 169°E) is oceanic (Conrad Index of Continentality  = −5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6°C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally. PMID:24691026

  8. Winter climate limits subantarctic low forest growth and establishment.

    Science.gov (United States)

    Harsch, Melanie A; McGlone, Matt S; Wilmshurst, Janet M

    2014-01-01

    Campbell Island, an isolated island 600 km south of New Zealand mainland (52 °S, 169 °E) is oceanic (Conrad Index of Continentality  =  -5) with small differences between mean summer and winter temperatures. Previous work established the unexpected result that a mean annual climate warming of c. 0.6 °C since the 1940's has not led to upward movement of the forest limit. Here we explore the relative importance of summer and winter climatic conditions on growth and age-class structure of the treeline forming species, Dracophyllum longifolium and Dracophyllum scoparium over the second half of the 20th century. The relationship between climate and growth and establishment were evaluated using standard dendroecological methods and local climate data from a meteorological station on the island. Growth and establishment were correlated against climate variables and further evaluated within hierarchical regression models to take into account the effect of plot level variables. Winter climatic conditions exerted a greater effect on growth and establishment than summer climatic conditions. Establishment is maximized under warm (mean winter temperatures >7 °C), dry winters (total winter precipitation <400 mm). Growth, on the other hand, is adversely affected by wide winter temperature ranges and increased rainfall. The contrasting effect of winter warmth on growth and establishment suggests that winter temperature affects growth and establishment through differing mechanisms. We propose that milder winters enhance survival of seedlings and, therefore, recruitment, but increases metabolic stress on established plants, resulting in lower growth rates. Future winter warming may therefore have complex effects on plant growth and establishment globally.

  9. Changes in visual quality, physiological and biochemical parameters assessed during the postharvest storage at chilling or non-chilling temperatures of three sweet basil (Ocimum basilicum L.) cultivars.

    Science.gov (United States)

    Fratianni, Florinda; Cefola, Maria; Pace, Bernardo; Cozzolino, Rosaria; De Giulio, Beatrice; Cozzolino, Autilia; d'Acierno, Antonio; Coppola, Raffaele; Logrieco, Antonio Francesco; Nazzaro, Filomena

    2017-08-15

    Leaves of three different sweet basil (Ocimum basilicum L.) cultivars (Italico a foglia larga, Cammeo, and Italiano classico) packed in macro-perforated polyethylene bags were stored at chilling (4°C) or non-chilling temperature (12°C) for 9days. During storage, visual quality, physiological (respiration rate, ethylene production, ammonium content) and chemical (antioxidant activity, total polyphenols and polyphenol profile) parameters were measured. Detached leaves stored at chilling temperature showed visual symptoms related to chilling injury, while ethylene production and ammonium content resulted associated to cultivar sensibility to damage at low temperature. Storage at 4°C caused a depletion in polyphenols content and antioxidant capability, which was preserved at 12°C. Regarding the polyphenols profile, stressful storage conditions did not enhance the phenolic metabolism. However, leaves stored at 12°C did not loss a significant amount of metabolites respect to fresh leaves, suggesting the possibility to extend the storability after the expiration date, for a possible recovery of bioactive compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Klaus Winter (1930 - 2015)

    CERN Multimedia

    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...

  12. Winter fuels report

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. Nuclear Winter: The implications for civil defense

    International Nuclear Information System (INIS)

    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 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

  14. Nuclear Winter: Implications for civil defense

    Energy Technology Data Exchange (ETDEWEB)

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

    1988-05-01

    ''Nuclear Winter'' is the term given to the cooling hypothesized to occur in the Northern Hemisphere following a nuclear war as the result of the injection of smoke from burning cities into the atmosphere. The voluminous literature on this subject produced since the paper was published in 1983 by Turco, Toon, Ackerman, Pollack, and Sagen (TTAPS) has been reviewed. Three-dimensional global circulation models have resulted in reduced estimates of cooling---15 to 25/degree/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 is likely to be a direct threat to human survival for populations with the wherewithal to survive normal January temperatures. The principal threat from nuclear winter is to food production, and this could present problems to third parties who are without food reserves. Loss of a crop year is neither a new nor an unexpected threat from nuclear war to the United States 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 United States 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.

  15. Chloroplast RNA-Binding Protein RBD1 Promotes Chilling Tolerance through 23S rRNA Processing in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Shuai Wang

    2016-05-01

    Full Text Available Plants have varying abilities to tolerate chilling (low but not freezing temperatures, and it is largely unknown how plants such as Arabidopsis thaliana achieve chilling tolerance. Here, we describe a genome-wide screen for genes important for chilling tolerance by their putative knockout mutants in Arabidopsis thaliana. Out of 11,000 T-DNA insertion mutant lines representing half of the genome, 54 lines associated with disruption of 49 genes had a drastic chilling sensitive phenotype. Sixteen of these genes encode proteins with chloroplast localization, suggesting a critical role of chloroplast function in chilling tolerance. Study of one of these proteins RBD1 with an RNA binding domain further reveals the importance of chloroplast translation in chilling tolerance. RBD1 is expressed in the green tissues and is localized in the chloroplast nucleoid. It binds directly to 23S rRNA and the binding is stronger under chilling than at normal growth temperatures. The rbd1 mutants are defective in generating mature 23S rRNAs and deficient in chloroplast protein synthesis especially under chilling conditions. Together, our study identifies RBD1 as a regulator of 23S rRNA processing and reveals the importance of chloroplast function especially protein translation in chilling tolerance.

  16. Influence of mist-chilling on post-harvest quality of fresh strawberries Cv. Mara des Bois and Gariguette

    Energy Technology Data Exchange (ETDEWEB)

    Allais, Irene [Cemagref, UMR Genial, 24, avenue des Landais B.P. 50085, 63172 Aubiere Cedex (France); Letang, Guy [Cemagref, UMR Genial, Parc de Tourvoie, B.P. 44, 92163 Antony Cedex (France)

    2009-09-15

    The aim of this study was to assess the impact of mist-chilling on high-grade strawberry post-harvest quality (Cultivars ''Gariguette'' and ''Mara des Bois''). Strawberries were chilled at 2 C using three processes: air blast chilling at 0.3 m s{sup -1} or 1 m s{sup -1} and mist-chilling at 1 m s{sup -1}. After chilling, fruits were submitted to different distribution chains characterised by different handling conditions and storage temperatures (2 C or 7 C) and by a 12 h retailing step at 20 C. Strawberry quality was assessed by measuring 7 parameters: weight loss, commercial loss, firmness, sugar content, acidity, colour and sensory quality. Compared to air-chilling, mist-chilling did not reduce chilling time but it reduced weight loss by 20-40%. Mist-chilling had no detrimental effect on commercial loss defined as the percentage of fruit more than 1/3 of surface affected. It did not induce any major changes on strawberry quality. Temperature fluctuations undergone during cold storage and retailing had a detrimental effect on weight loss. The beneficial effect of packaging on weight loss was confirmed. (author)

  17. Sage-grouse habitat selection during winter in Alberta

    Science.gov (United States)

    Carpenter, Jennifer L.; Aldridge, Cameron L.; Boyce, Mark S.

    2010-01-01

    Greater sage-grouse (Centrocercus urophasianus) are dependent on sagebrush (Artemisia spp.) for food and shelter during winter, yet few studies have assessed winter habitat selection, particularly at scales applicable to conservation planning. Small changes to availability of winter habitats have caused drastic reductions in some sage-grouse populations. We modeled winter habitat selection by sage-grouse in Alberta, Canada, by using a resource selection function. Our purpose was to 1) generate a robust winter habitat-selection model for Alberta sage-grouse; 2) spatially depict habitat suitability in a Geographic Information System to identify areas with a high probability of selection and thus, conservation importance; and 3) assess the relative influence of human development, including oil and gas wells, in landscape models of winter habitat selection. Terrain and vegetation characteristics, sagebrush cover, anthropogenic landscape features, and energy development were important in top Akaike's Information Criterionselected models. During winter, sage-grouse selected dense sagebrush cover and homogenous less rugged areas, and avoided energy development and 2-track truck trails. Sage-grouse avoidance of energy development highlights the need for comprehensive management strategies that maintain suitable habitats across all seasons. ?? 2010 The Wildlife Society.

  18. Use mobile pumps and liquid chilling water units to provide chilled water for nuclear reactor during nuclear power plant accident

    International Nuclear Information System (INIS)

    Zhang Guobin; Feng Jiaxuan

    2012-01-01

    From the nuclear accident in Japan Fuksuhima in March this year, despite a shut down of the reactor, the residue heat inside the reactor was not able to remove due to the failure of the cooling system and it finally caused the catastrophe. It was observed that when the failure of the cooling system after an earthquake of magnitude 9 and a tsunami of 28 meters height, the containment vessel for the reactor core was still able to maintain its integrity in the first 24 hours before the first explosion was happened. A backup emergency heat removal system for nuclear power plants using mo- bile pumps and liquid chilling units has been proposed 20 years ago by Cheung [Ref. 1]. Due to the fact that there are more than 400 nuclear power plants around the world and 10% of them are located in earthquake active zone, together with the aging of some of the power plants which were built more than 30 years ago, the risk of another nuclear accident becomes high. An emergency safety measure has to be designed in order to deal with the unforeseen scenario. This re- port re-visits the proposal again; to re-design to the suit the need and to integrate with the current situation of the nuclear industry. (authors)

  19. Impacts of +2 °C global warming on winter tourism demand in Europe

    NARCIS (Netherlands)

    Damm, Andrea; Greuell, Wouter; Landgren, Oskar; Prettenthaler, Franz

    2017-01-01

    Increasing temperatures and snow scarce winter seasons challenge the winter tourism industry. In this study the impacts of +2 °C global warming on winter tourism demand in Europe's ski tourism related NUTS-3 regions are quantified. Using time series regression models, the relationship between

  20. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    KAUST Repository

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Lawrence J.; Bower, Amy S.; Kö hl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-01-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented

  1. Internet surveillance, regulation, and chilling effects online: a comparative case study

    Directory of Open Access Journals (Sweden)

    Jonathon W. Penney

    2017-05-01

    Full Text Available With internet regulation and censorship on the rise, states increasingly engaging in online surveillance, and state cyber-policing capabilities rapidly evolving globally, concerns about regulatory “chilling effects” online—the idea that laws, regulations, or state surveillance can deter people from exercising their freedoms or engaging in legal activities on the internet have taken on greater urgency and public importance. But just as notions of “chilling effects” are not new, neither is skepticism about their legal, theoretical, and empirical basis; in fact, the concept remains largely un-interrogated with significant gaps in understanding, particularly with respect to chilling effects online. This work helps fill this void with a first-of-its-kind online survey that examines multiple dimensions of chilling effects online by comparing and analyzing responses to hypothetical scenarios involving different kinds of regulatory actions—including an anti-cyberbullying law, public/private sector surveillance, and an online regulatory scheme, based on the Digital Millennium Copyright Act (DMCA, enforced through personally received legal threats/notices. The results suggest not only the existence and significance of regulatory chilling effects online across these different scenarios but also evidence a differential impact—with personally received legal notices and government surveillance online consistently having the greatest chilling effect on people’s activities online—and certain online activities like speech, search, and personal sharing also impacted differently. The results also offer, for the first time, insights based on demographics and other similar factors about how certain people and groups may be more affected than others, including findings that younger people and women are more likely to be chilled; younger people and women are less likely to take steps to resist regulatory actions and defend themselves; and anti

  2. Effect of heat treatment and shelf life on chilling injury of mango cv. Nam Dok Mai

    Directory of Open Access Journals (Sweden)

    Apiradee Muangdech

    2017-10-01

    Full Text Available This study was aimed to investigate the effect of heat treatment and shelf life on chilling injury of mango cv.Nam Dok Mai.The heat treatment of mango pulp during storage were determined by hot air oven set at 34 and 38°C for three intervals, as 24, 48, and 72 hours, then they were subsequently stored at 5°C for 10, 20, and 30 days to determine the appropriate shelf life. The findings showed that the symptom of mango fruit after chilling injury appeared within the 30th day of storage at 5°C. Several symptoms of mango fruit after chilling injury treatment were observed, i.e., pitting, browning on the skin, water soaking, and rapid rotting of the fruits that resulted in shorter shelf life. It was found that chilling injury mangoes had lower level of total soluble solid, higher disease incidence, and lower quality of fruit when compared with normal ripe-mango fruits at 25°C. Mango fruits treated at 34°C for either 24 or 48 hours, and at 38°C for 24 hours prior to cold storage at 5°C for 10 and 20 days showed a significant reduction in the chilling injury (CI index when compared to that of non-heated fruits. On the other hand, the heat treatment did not affect fruit weight loss, firmness, color changes, and water soaking at 5°C.

  3. Amelioration of chilling effects by CO/sub 2/ enrichment. [Echinochloa crus-galli; Eleusine indica

    Energy Technology Data Exchange (ETDEWEB)

    Potvin, C.

    1985-01-01

    To analyze the effect of CO/sub 2/ enrichment on the chilling-sensitivity of C/sub 4/ plants from contrasting habitats, plants of Echinochloa crus-galli from Quebec, North Carolina and Mississippi and Eleusine indica from Mississippi were grown for 4 weeks under three thermoperiods (28/22, 24/18 and 21/15/sup 0/C) and two atmospheric CO/sub 2/ concentrations (350 and 675 ..mu..l l/sup -1/). They were then submitted to 1 night chilling at 7/sup 0/C. Photosynthetic carbon uptake, stomatal conductances, and internal CO/sub 2/ concentration were measured using an infra-red gas analyzer in an open system before and after the chilling and during the recovery. Chilling induces a decrease in photosynthesis and conductance and, at 350 ..mu..l l/sup -1/, in internal CO/sub 2/. The decrease in photosynthesis is less important for high CO/sub 2/ grown plants at 28/22/sup 0/C. Chilling generates chlorotic bands on leaf blades but less chlorosis is observed in enriched CO/sub 2/. 17 references, 3 figures, 3 tables.

  4. Quality indicators and shelf life of red octopus (Octopus maya in chilling storage

    Directory of Open Access Journals (Sweden)

    Mariel GULLIAN-KLANIAN

    2016-01-01

    Full Text Available Abstract There are no precedents concerning the quality of Octopus maya during chilled storage. This study evaluated the shelf life of the red octopus in chilling storage (4oC and the correlation of the sensory quality index with microbiological counting and the biochemical indicators (hypoxanthine, histamine and volatile amines. A total of 112 whole raw octopi (average weight of 896 g were randomly selected from seven batches and exposed to 4°C for 18, 24, 48, 72, 84, 96, and 100 h. The histamine concentration (91.7%, followed by the counts of psychrotrophic bacteria (5.5% and hypoxanthine (2.2%, were the predictors from the redundancy analysis that better explained the changes taking place during the chilling hours. After 72 h of chilling, the microbial count was determined to be log 4.7 CFU/g, and the octopus samples were classified as B quality (minor sensory quality defects based on the sensory quality scale. Although the samples were not classified as unacceptable at 100 h of refrigeration by the sensory index, the level of histamine reached the defect action level (5 mg/100 g as ruled by the International Food Safety Authorities. The shelf life of the red octopus in chilling storage was predicted to be 119 h.

  5. Comparative transcriptome profiling of chilling stress responsiveness in grafted watermelon seedlings.

    Science.gov (United States)

    Xu, Jinhua; Zhang, Man; Liu, Guang; Yang, Xingping; Hou, Xilin

    2016-12-01

    Rootstock grafting may improve the resistance of watermelon plants to low temperatures. However, information regarding the molecular responses of rootstock grafted plants to chilling stress is limited. To elucidate the molecular mechanisms of chilling tolerance in grafted plants, the transcriptomic responses of grafted watermelon under chilling stress were analyzed using RNA-seq analysis. Sequencing data were used for digital gene expression (DGE) analysis to characterize the transcriptomic responses in grafted watermelon seedlings. A total of 702 differentially-expressed genes (DEGs) were found in rootstock grafted (RG) watermelon relative to self-grafted (SG) watermelon; among these genes, 522 genes were up-regulated and 180 were down-regulated. Additionally, 164 and 953 genes were found to specifically expressed in RG and SG seedlings under chilling stress, respectively. Functional annotations revealed that up-regulated DEGs are involved in protein processing, plant-pathogen interaction and the spliceosome, whereas down-regulated DEGs are associated with photosynthesis. Moreover, 13 DEGs were randomly selected for quantitative real time PCR (qRT-PCR) analysis. The expression profiles of these 13 DEGs were consistent with those detected by the DGE analysis, supporting the reliability of the DGE data. This work provides additional insight into the molecular basis of grafted watermelon responses to chilling stress. Copyright © 2016. Published by Elsevier Masson SAS.

  6. The correlation between heat-shock protein accumulation and persistence and chilling tolerance in tomato fruit

    International Nuclear Information System (INIS)

    Sabehat, A.; Weiss, D.; Lurie, S.

    1996-01-01

    Heating tomato fruit (Lycopersicon esculentum) for 48 h at 38 degrees C prevented chilling injury from developing after 21 d at 2 degrees C, whereas unheated fruit developed high levels of injury. Although the overall protein pattern as seen by Coomassie blue staining was similar from heated and unheated fruit, some high- and many low-molecular-mass proteins were observed in the heated fruit that were absent or present in reduced amounts in unheated fruit. When fruit were injected with [35S]methionine at harvest and then heated, they accumulated high levels of specific radiolabeled proteins that could still be detected after 21 d at 2 degrees C. If the fruit were held at 20 degrees C after heating, the label in the proteins declined rapidly and these fruit were also sensitive to chilling injury. Hsp70 antibody reacted more strongly with proteins from heated and chilled fruit than with proteins from chilled fruit. Hsp18.1 antibody reacted strongly with proteins from heated fruit but not with those from unheated fruit. A 23-kD protein, highly labeled in heated fruit but not in unheated fruit, had its amino terminus sequenced. To our knowledge, this is the first report showing a relationship between the persistence of heat-shock proteins and chilling tolerance in a plant tissue

  7. [Temporal and spatial change of climate resources and meteorological disasters under climate change during winter crop growing season in Guangdong Province, China.

    Science.gov (United States)

    Wang, Hua; Chen, Hui Hua; Tang, Li Sheng; Wang, Juan Huai; Tang, Hai Yan

    2018-01-01

    Trend analysis method was applied to analyze the general variation characteristics of the climate resources and meteorological disasters of growing season of the winter planting in Guangdong before (1961-1996) and after climate warming (1997-2015). Percentile method was employed to determine thresholds for extreme cold and drought in major planting regions, and the characteristics of extreme disasters since climate warming were analyzed. The results showed that, by comparing 1997-2015 with 1961-1996, the heat value in winter growing season increased significantly. The belt with a higher heat value, where the average temperature was ≥15 ℃ and accumulated temperature was ≥2200 ℃·d, covered the main winter production regions as Shaoguan, Zhanjiang, Maoming, Huizhou, Meizhou and Guangzhou. Meanwhile, the precipitation witnessed a slight increase. The regions with precipitations of 250-350 mm included Zhanjiang, Maoming, Huizhou, Guangzhou and Meizhou. Chilling injury in the winter planting season in the regions decreased, the belt with an accumulated chilling of climate resources and the occurrence law of meteorological disasters in growing season.

  8. Winter/Summer Monsoon Experiment

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Winter/Summer Monsoon Experiment (MONEX) was conducted during the First Global GARP (Global Atmospheric Research Program) Experiment (FGGE). An international...

  9. The meaning of nuclear winter

    International Nuclear Information System (INIS)

    Geiger, H.J.

    1987-01-01

    In this paper the author reviews the history and origins of the basic ideas underlying nuclear winter; and findings and predictions of several groups regarding this topic. The author reviews some of the further developments and scientific analyses regarding nuclear winter since the initial announcements of 1983, touching on some of the revisions and controversies and trying to indicate the current status of the field

  10. Seeking explanations for recent changes in abundance of wintering Eurasian Wigeon (Anas penelope) in northwest Europe

    DEFF Research Database (Denmark)

    Fox, Anthony David; Dalby, Lars; Christensen, Thomas Kjær

    2016-01-01

    the range. However, because over 75% of the population of over 1 million individuals winters in Belgium, the Netherlands, UK and France, there was no evidence for a major movement in the centre of gravity of the wintering distribution. Between-winter changes in overall flyway abundance were highly......We analysed annual changes in abundance of Eurasian Wigeon (Anas penelope) derived from mid-winter International Waterbird Census data throughout its northwest European flyway since 1988 using log-linear Poisson regression modelling. Increases in abundance in the north and east of the wintering...... range (Norway, Sweden, Denmark, Germany, Switzerland), stable numbers in the central range (Belgium,Netherlands,UKand France) and declining abundance in the west and south of the wintering range (Spain and Ireland) suggest a shift in wintering distribution consistent with milder winters throughout...

  11. Optimum Temperature for Storage of Fruit and Vegetables with Reference to Chilling Injury

    Science.gov (United States)

    Murata, Takao

    Cold storage is an important technique for preserving fresh fruit and vegetables. Deterioration due to ripening, senescence and microbiological disease can be retarded by storage at optimum temperature being slightly above the freezing point of tissues of fruit and vegetables. However, some fruit and vegetables having their origins in tropical or subtropical regions of the world are subject to chilling injury during transportation, storage and wholesale distribution at low temperature above freezing point, because they are usually sensitive to low temperature in the range of 15&digC to 0°C. This review will focus on the recent informations regarding chilling injury of fruit and vegetables, and summarize the optimum temperature for transportation and storage of fruit and vegetables in relation to chilling injury.

  12. Oxidative Stress Associated with Chilling Injury in Immature Fruit: Postharvest Technological and Biotechnological Solutions.

    Science.gov (United States)

    Valenzuela, Juan Luis; Manzano, Susana; Palma, Francisco; Carvajal, Fátima; Garrido, Dolores; Jamilena, Manuel

    2017-07-08

    Immature, vegetable-like fruits are produced by crops of great economic importance, including cucumbers, zucchini, eggplants and bell peppers, among others. Because of their high respiration rates, associated with high rates of dehydration and metabolism, and their susceptibility to chilling injury (CI), vegetable fruits are highly perishable commodities, requiring particular storage conditions to avoid postharvest losses. This review focuses on the oxidative stress that affects the postharvest quality of vegetable fruits under chilling storage. We define the physiological and biochemical factors that are associated with the oxidative stress and the development of CI symptoms in these commodities, and discuss the different physical, chemical and biotechnological approaches that have been proposed to reduce oxidative stress while enhancing the chilling tolerance of vegetable fruits.

  13. Thermal environment and air quality in office with personalized ventilation combined with chilled ceiling

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Kaczmarczyk, Jan; Melikov, Arsen Krikor

    2015-01-01

    The thermal environment and air quality conditions provided with combined system of chilled ceiling and personalized ventilation (PV) were studied in a simulated office room for two occupants. The proposed system was compared with total volume HVAC solutions used today, namely mixing ventilation...... and chilled ceiling combined with mixing ventilation. The objective of the study was to evaluate whether PV can be the only ventilation system in the rooms equipped with chilled ceiling. The room air temperature was 26°C in cases with traditional systems and 28°C when PV was used. PV supplied air...... with the temperature of 25°C. PV improved thermal conditions and was up to nearly 10 times more efficient in delivering clean air at workstations than mixing ventilation systems, which resulted in strong protection of occupants from the cross-infection. In the room space outside workstations no substantial differences...

  14. Chilling-induced tomato flavor loss is associated with altered volatile synthesis and transient changes in DNA methylation

    Science.gov (United States)

    Commercial tomatoes are widely perceived by consumers as lacking flavor. A major part of that problem is a postharvest handling system that chills fruit. Low-temperature storage is widely used to slow ripening and reduce decay. However, chilling results in loss of flavor. Flavor-associated volatiles...

  15. Chemical Changes In Shortfin Scad (Decapterus Macrosoma) at Chilled (4 degree Celcius) and Frozen (-18 degree Celcius) Storage

    International Nuclear Information System (INIS)

    Fazilah Fazilin Juhari; Norizzah Abd Rashid; Seng, C.C.; Anida Yusoff; Emilia Azrina Mohd Bakri

    2016-01-01

    The aim of this study was to determine the chemical changes in muscle tissue of shortfin scad during storage at chilled (4 degree Celcius) and frozen (-18 degree Celcius) conditions for 18 days. The chemical changes were monitored every three days for Thiobarbituric acid (TBA), Peroxide value (PV), Total Volatile Base Nitrogen (TVBN) and Trimethylamine (TMA) content. Results show that there was a significant difference (p<0.05) in peroxide and TBA values between chilled and frozen shortfin scad starting from day 3. The highest PV values occured in chilled and frozen shortfin scad at day 12 (1.57 mEq/ kg and 1.13 mEq/ kg, respectively), and then decreased due to decomposition of hydroperoxides to secondary products such as aldehydes, alcohols and ketones. In contrast, TBA reached the highest values at day 15 for both chilled and frozen shortfin scad. For TVBN content, only the chilled sample shows significant increased (p<0.05) with storage time. The TVBN values declined significantly (p<0.05) for frozen shortfin scad. The TMA values for both chilled and frozen shortfin scad increased during storage. However, the TMA values increased at a faster rate in chilled compared to frozen shortfin scad. Based on the PV, TBA, TVBN and TMA values, chilled shortfin scad undergoes spoilage at a faster rate compared to the frozen shortfin scad. (author)

  16. Dorsoventral variations in dark chilling effects on photosynthesis and stomatal function in Paspalum dilatatum leaves.

    Science.gov (United States)

    Soares-Cordeiro, Ana Sofia; Driscoll, Simon P; Arrabaça, Maria Celeste; Foyer, Christine H

    2011-01-01

    The effects of dark chilling on the leaf-side-specific regulation of photosynthesis were characterized in the C(4) grass Paspalum dilatatum. CO(2)- and light-response curves for photosynthesis and associated parameters were measured on whole leaves and on each leaf side independently under adaxial and abaxial illumination before and after plants were exposed to dark chilling for one or two consecutive nights. The stomata closed on the adaxial sides of the leaves under abaxial illumination and no CO(2) uptake could be detected on this surface. However, high rates of whole leaf photosynthesis were still observed because CO(2) assimilation rates were increased on the abaxial sides of the leaves under abaxial illumination. Under adaxial illumination both leaf surfaces contributed to the inhibition of whole leaf photosynthesis observed after one night of chilling. After two nights of chilling photosynthesis remained inhibited on the abaxial side of the leaf but the adaxial side had recovered, an effect related to increased maximal ribulose-1,5-bisphosphate carboxylation rates (V(cmax)) and enhanced maximal electron transport rates (J(max)). Under abaxial illumination, whole leaf photosynthesis was decreased only after the second night of chilling. The chilling-dependent inhibition of photosynthesis was located largely on the abaxial side of the leaf and was related to decreased V(cmax) and J(max), but not to the maximal phosphoenolpyruvate carboxylase carboxylation rate (V(pmax)). Each side of the leaf therefore exhibits a unique sensitivity to stress and recovery. Side-specific responses to stress are related to differences in the control of enzyme and photosynthetic electron transport activities.

  17. Microbiological shelf life of fresh, chilled reindeer meat (M. longissimus dorsi

    Directory of Open Access Journals (Sweden)

    Eva Wiklund

    2011-04-01

    Full Text Available In this pilot study loin muscles (M. longissimus dorsi from six reindeer calves (aged 4 months were used to determine shelf life of fresh, chilled reindeer meat stored at +4 °C, measured as microbiological quality (aerobic microorganisms and Escherichia coli. The loins were collected at boning 3 days post slaughter and divided in five pieces that were randomly assigned to five different storage times; sampling directly after packaging and after chilled storage for 2, 3, 4 and 5 weeks at +4 °C. Samples were vacuum packaged and transported chilled to Hjortens Laboratory in Östersund, Sweden (accredited by SWEDAC according to SS-EN ISO/IEC 17025:2005 for food analysis where the storage, microbiological sampling and analysis took place according to the protocols of Nordic Committee on Food Analysis (NMKL. The total amount of aerobic microorganisms at the first sampling directly after packaging (three days post slaughter was 3.4 ± 0.3 log10 CFU/g. After two and three weeks of vacuum packaged chilled storage at +4°C the microbiological quality of the samples was on the border-line to poor (6.8 ± 0.3 log10 CFU/g. At four and five weeks of chilled storage the levels of aerobic microorganisms were significantly highest (P≤0.05 and the limit for acceptable quality of 7 log10 CFU/g aerobic bacteria had been passed (7.3 ± 0.3 log10 CFU/g and 7.8 ± 0.3 log10 CFU/g, respectively. Very few of the reindeer meat samples were contaminated with Escherichia coli bacteria. The results from the present pilot study suggest that storage time for vacuum packaged fresh, chilled reindeer meat should not exceed 3 weeks at a temperature of +4 °C.

  18. Integrated solar water-heater and solar water cooler performance during winter time

    International Nuclear Information System (INIS)

    Shaikh, N.U.; Siddiqui, M.A

    2012-01-01

    Solar powered water heater and water cooler is an important contribution for the reduction of fossil fuel consumptions and harmful emissions to the environment. This study aims to harness the available solar potential of Pakistan and provide an option fulfilling the domestic hot and cold water demands during winter and summer seasons respectively. The system was designed for the tap-water temperature of 65 degree C (149 degree F) and the chilled drinking-water temperature of 14 degree C (57 degree F) that are the recommended temperatures by World Health Organization (WHO). The solar water heater serves one of the facilities of the Department of Mechanical Engineering at NED University of Engineering and Technology whereas, the solar water cooler will provide drinking water to approximately 50 people including both faculty and students. A pair of single glazed flat plate solar collector was installed to convert solar radiations to heat. Hot water storage and supply system was carefully designed and fabricated to obtain the designed tap-water temperature. Vapour-absorption refrigeration system was designed to chill drinking water. Intensity of solar radiations falling on the solar collector, water temperatures at the inlet and outlet of the solar collectors and the tap water temperature were measured and analyzed at different hours of the day and at different days of the month. The results show that the installed solar collector system has potential to feed hot water of temperatures ranging from 65 degree C (149 degree F) to 70 Degree C (158 degree F), that is the required hot water temperature to operate a vapour absorption chilled water production system. (author)

  19. Nondestructive detection of total viable count changes of chilled pork in high oxygen storage condition based on hyperspectral technology

    Science.gov (United States)

    Zheng, Xiaochun; Peng, Yankun; Li, Yongyu; Chao, Kuanglin; Qin, Jianwei

    2017-05-01

    The plate count method is commonly used to detect the total viable count (TVC) of bacteria in pork, which is timeconsuming and destructive. It has also been used to study the changes of the TVC in pork under different storage conditions. In recent years, many scholars have explored the non-destructive methods on detecting TVC by using visible near infrared (VIS/NIR) technology and hyperspectral technology. The TVC in chilled pork was monitored under high oxygen condition in this study by using hyperspectral technology in order to evaluate the changes of total bacterial count during storage, and then evaluate advantages and disadvantages of the storage condition. The VIS/NIR hyperspectral images of samples stored in high oxygen condition was acquired by a hyperspectral system in range of 400 1100nm. The actual reference value of total bacteria was measured by standard plate count method, and the results were obtained in 48 hours. The reflection spectra of the samples are extracted and used for the establishment of prediction model for TVC. The spectral preprocessing methods of standard normal variate transformation (SNV), multiple scatter correction (MSC) and derivation was conducted to the original reflectance spectra of samples. Partial least squares regression (PLSR) of TVC was performed and optimized to be the prediction model. The results show that the near infrared hyperspectral technology based on 400-1100nm combined with PLSR model can describe the growth pattern of the total bacteria count of the chilled pork under the condition of high oxygen very vividly and rapidly. The results obtained in this study demonstrate that the nondestructive method of TVC based on NIR hyperspectral has great potential in monitoring of edible safety in processing and storage of meat.

  20. Evaluating the ChillFish Biofeedback Game with Children with ADHD

    DEFF Research Database (Denmark)

    Sonne, Tobias; Jensen, Mads Møller

    2016-01-01

    Breathing exercises have been shown to have multiple benefits for children with Attention Deficit Hyperactivity Disorder (ADHD). However, these children can have issues retaining attention to such an exercise. In this paper we present a study of ChillFish, a respiration game for children with ADHD....... Our findings show tendencies that the game works in terms of having a calming effect. However, the study also highlighted issues of evaluating biofeedback games with children with ADHD that are not present when evaluating with adults. This work presents an iteration in the ChillFish development cycle...

  1. Microstructural Evolution in Intensively Melt Sheared Direct Chill Cast Al-Alloys

    Science.gov (United States)

    Jones, S.; Rao, A. K. Prasada; Patel, J. B.; Scamans, G. M.; Fan, Z.

    The work presented here introduces the novel melt conditioned direct chill casting (MC-DC) technology, where intensive melt shearing is applied to the conventional direct-chill casting process. MC-DC casting can successfully produce high quality Al-alloy billets. The results obtained from 80 mm diameter billets cast at speed of 200 mm/min show that MC-DC casting of Al-alloys, substantially refines the microstructure and reduces macro-segregation. In this paper, we present the preliminary results and discuss microstructural evolution during MC-DC casting of Al-alloys.

  2. Quality indicators and shelf life of red octopus (Octopus maya) in chilling storage

    OpenAIRE

    GULLIAN-KLANIAN,Mariel; SÁNCHEZ-SOLÍS,María José; TERRATS-PRECIAT,Montserrat; DELGADILLO-DÍAZ,Mariana; ARANDA,Javier

    2016-01-01

    Abstract There are no precedents concerning the quality of Octopus maya during chilled storage. This study evaluated the shelf life of the red octopus in chilling storage (4oC) and the correlation of the sensory quality index with microbiological counting and the biochemical indicators (hypoxanthine, histamine and volatile amines). A total of 112 whole raw octopi (average weight of 896 g) were randomly selected from seven batches and exposed to 4°C for 18, 24, 48, 72, 84, 96, and 100 h. The h...

  3. Effects of aluminum and copper chill on mechanical properties and microstructures of Cu-Zn-Al alloys with sand casting

    Science.gov (United States)

    Ardhyananta, Hosta; Wibisono, Alvian Toto; Ramadhani, Mavindra; Widyastuti, Farid, Muhammad; Gumilang, Muhammad Shena

    2018-04-01

    Cu-Zn-Al alloy is one type of brass, which has high strength and high corrosion resistant. It has been applied on ship propellers and marine equipment. In this research, the addition of aluminum (Al) with variation of 1, 2, 3, 4% aluminum to know the effect on mechanical properties and micro structure at casting process using a copper chill and without copper chill. This alloy is melted using furnace in 1100°C without holding. Then, the molten metal is poured into the mold with copper chill and without copper chill. The speciment of Cu-Zn-Al alloy were chracterized by using Optical Emission Spectroscopy (OES), Metallography Test, X-Ray Diffraction (XRD), Hardness Test of Rockwell B and Charpy Impact Test. The result is the addition of aluminum and the use of copper chill on the molds can reduce the grain size, increases the value of hardness and impact.

  4. Defence Reporter. Winter 2012

    Science.gov (United States)

    2012-01-01

    TMAP Polarisation Slant Angle Module Documentation Dstl, Portsdown West (GB) (2012) This report documents the mathematics and Matlab implementation of...a TMAP , (Threat Modelling and Analysis Program) module calculating the polarisation slant angle for use in aircraft engagement modelling. The

  5. Winter Season Mortality: Will Climate Warming Bring Benefits?

    Science.gov (United States)

    Kinney, Patrick L; Schwartz, Joel; Pascal, Mathilde; Petkova, Elisaveta; Tertre, Alain Le; Medina, Sylvia; Vautard, Robert

    2015-06-01

    Extreme heat events are associated with spikes in mortality, yet death rates are on average highest during the coldest months of the year. Under the assumption that most winter excess mortality is due to cold temperature, many previous studies have concluded that winter mortality will substantially decline in a warming climate. We analyzed whether and to what extent cold temperatures are associated with excess winter mortality across multiple cities and over multiple years within individual cities, using daily temperature and mortality data from 36 US cities (1985-2006) and 3 French cities (1971-2007). Comparing across cities, we found that excess winter mortality did not depend on seasonal temperature range, and was no lower in warmer vs. colder cities, suggesting that temperature is not a key driver of winter excess mortality. Using regression models within monthly strata, we found that variability in daily mortality within cities was not strongly influenced by winter temperature. Finally we found that inadequate control for seasonality in analyses of the effects of cold temperatures led to spuriously large assumed cold effects, and erroneous attribution of winter mortality to cold temperatures. Our findings suggest that reductions in cold-related mortality under warming climate may be much smaller than some have assumed. This should be of interest to researchers and policy makers concerned with projecting future health effects of climate change and developing relevant adaptation strategies.

  6. Cypripedium calceolus germination in situ: seed longevity, and dormancy breakage by long incubation and cold winters

    Directory of Open Access Journals (Sweden)

    Hanne N. Rasmussen

    2012-02-01

    Full Text Available A successful in situ germination experiment with Cypripedium calceolus, the European Lady’s slipper, is reported here for the first time. The seeds originated from controlled pollinations within and between two closely related Danish populations. The seeds were sown ripe in seed packets in proximity of mother plants. Germination was first observed after 4.5 y in the ground, following two successive cold and snowy winters, and only in one population. Seedlings expanded through the sides of the broken testa and were hair-less. A corresponding set of seeds, germinated in vitro as asymbiotic controls, responded positively to repeated cold stratifications after long incubation, suggesting that time (leaching? and chilling are dormancy breakage factors.

  7. Georgia Institute of Technology chilled water system evaluation and master plan

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-05-15

    As the host of the Olympic Village for the 1996 Atlanta Olympics, Georgia Tech has experienced a surge in construction activities over the last three years. Over 1.3 million square feet of new buildings have been constructed on the Georgia Tech campus. This growth has placed a strain on the Georgia Tech community and challenged the facilities support staff charged with planning and organizing utility services. In concert with Olympic construction, utility planners have worked to ensure long term benefits for Georgia Tech facilities while meeting the short term requirements of the Olympic Games. The concentration of building construction in the northwest quadrant of the campus allowed planners to construct a satellite chilled water plant to serve the needs of this area and provide the opportunity to integrate this section of the campus with the main campus chilled water system. This assessment and master plan, funded in part by the US Department of Energy, has evaluated the chilled water infrastructure at Georgia Tech, identified ongoing problems and made recommendations for long term chilled water infrastructure development and efficiency improvements. The Georgia Tech office of Facilities and RDA Engineering, Inc. have worked together to assemble relevant information and prepare the recommendations contained in this document.

  8. Rapid chilling cannot prevent inferior pork quality caused by high preslaughter stress

    NARCIS (Netherlands)

    Hambrecht, E.; Eissen, J.J.; Klein, W.J.H.; Ducro, B.J.; Smits, C.H.M.; Verstegen, M.W.A.; Hartog, den L.A.

    2004-01-01

    The present experiment investigated whether increasing chilling rate could improve meat quality in pigs exposed to either minimal or high stress immediately preslaughter. Pigs (n = 192) were offspring of halothane-free lines. On various days, four groups of 48 pigs were processed at a commercial

  9. Characterization of four Paenibacillus species isolated from pasteurized, chilled ready-to-eat meals

    NARCIS (Netherlands)

    Helmond, Mariette; Nierop Groot, Masja N.; Bokhorst-van de Veen, van Hermien

    2017-01-01

    Food spoilage is often caused by microorganisms. The predominant spoilage microorganisms of pasteurized, chilled ready-to-eat (RTE) mixed rice-vegetable meals stored at 7 °C were isolated and determined as Paenibacillus species. These sporeforming psychrotrophic bacteria are well adapted to grow

  10. Experimental Investigation of a Mechanical Vapour Compression Chiller at Elevated Chilled Water Temperatures

    KAUST Repository

    Thu, Kyaw

    2017-05-18

    The performance of a Mechanical Vapour Compression (MVC) chiller is experimentally investigated under operating conditions suitable for sensible cooling. With the emergence of the energy efficient dehumidification systems, it is possible to decouple the latent load from the MVC chillers which can be operated at higher chilled water temperature for handling sensible cooling load. In this article, the performance of the chiller is evaluated at the elevated chilled water outlet temperatures (7 – 17° C) at various coolant temperatures (28 – 32° C) and flow rates (ΔT = 4 and 5° C) for both full- and part-load conditions. Keeping the performance at the AHRI standard as the baseline condition, the efficacy of the chiller in terms of compression ratio, cooling capacity and COP at aforementioned conditions is quantified experimentally. It is observed that for each one-degree Celsius increase in the chilled water temperature, the COP of the chiller improves by about 3.5% whilst the cooling capacity improvement is about 4%. For operation at 17° C chilled water outlet temperature, the improvements in COP and cooling capacity are between 37 – 40% and 40 – 45%, respectively, compared to the performance at the AHRI standards. The performance of the MVC chiller at the abovementioned operation conditions is mapped on the chiller performance characteristic chart.

  11. Effect of modified atmosphere packaging on chilling-induced peel browning in banana

    NARCIS (Netherlands)

    Nguyen, T.B.T.; Ketsa, S.; Doorn, van W.G.

    2004-01-01

    Sucrier bananas (Musa AA Group; cultivar locally known as Kluai Khai) were stored at 10degreesC, which results in chilling injury (CI). Fruit was held in packages with and without a modified atmosphere (MA). Oxygen levels in the MA packages were about 12% while CO2 concentrations were about 4%. MA

  12. Experimental Investigation of a Mechanical Vapour Compression Chiller at Elevated Chilled Water Temperatures

    KAUST Repository

    Thu, Kyaw; Saththasivam, Jayaprakash; Saha, Bidyut Baran; Chua, Kian Jon; Srinivasa Murthy, S.; Ng, Kim Choon

    2017-01-01

    The performance of a Mechanical Vapour Compression (MVC) chiller is experimentally investigated under operating conditions suitable for sensible cooling. With the emergence of the energy efficient dehumidification systems, it is possible to decouple the latent load from the MVC chillers which can be operated at higher chilled water temperature for handling sensible cooling load. In this article, the performance of the chiller is evaluated at the elevated chilled water outlet temperatures (7 – 17° C) at various coolant temperatures (28 – 32° C) and flow rates (ΔT = 4 and 5° C) for both full- and part-load conditions. Keeping the performance at the AHRI standard as the baseline condition, the efficacy of the chiller in terms of compression ratio, cooling capacity and COP at aforementioned conditions is quantified experimentally. It is observed that for each one-degree Celsius increase in the chilled water temperature, the COP of the chiller improves by about 3.5% whilst the cooling capacity improvement is about 4%. For operation at 17° C chilled water outlet temperature, the improvements in COP and cooling capacity are between 37 – 40% and 40 – 45%, respectively, compared to the performance at the AHRI standards. The performance of the MVC chiller at the abovementioned operation conditions is mapped on the chiller performance characteristic chart.

  13. Biochemical, sensory and microbiological attributes of bream (Megalobrama amblycephala) during partial freezing and chilled storage.

    Science.gov (United States)

    Song, Yongling; Luo, Yongkang; You, Juan; Shen, Huixing; Hu, Sumei

    2012-01-15

    Bream is one of the main farmed freshwater fish species in China. This study aimed to examine the nucleotide degradation of bream during partial freezing and chilled storage and to assess the possible usefulness of nucleotide ratios (K, Ki, H, P, Fr and G values) as freshness indices in comparison with sensory assessment and total viable counts. Total viable counts were 5.74 and 4.66 log(colony-forming units g(-1)) on the day of sensory rejection under chilled storage and partial freezing storage respectively. The inosine 5-monophosphate decrease and inosine increase were faster in chilled storage than in partial freezing storage. Hypoxanthine levels increased continuously with time under both storage regimes. Among the nucleotide ratios, the K, Ki, P, G and Fr values were superior to the H value and provided useful freshness indicators for both storage conditions. Bream in chilled storage were sensorially acceptable only up to 10 days, compared with 33 days for bream in partial freezing storage. Partial freezing delayed the nucleotide degradation of bream. Copyright © 2011 Society of Chemical Industry.

  14. 9 CFR 327.21 - Inspection procedures for chilled fresh and frozen boneless manufacturing meat.

    Science.gov (United States)

    2010-01-01

    ... fresh and frozen boneless manufacturing meat. 327.21 Section 327.21 Animals and Animal Products FOOD... MEAT AND POULTRY PRODUCTS INSPECTION AND VOLUNTARY INSPECTION AND CERTIFICATION IMPORTED PRODUCTS § 327.21 Inspection procedures for chilled fresh and frozen boneless manufacturing meat. (a) Definitions...

  15. Application of a Chilled Ammonia-based Process for CO2 Capture to Cement Plants

    NARCIS (Netherlands)

    Pérez-Calvo, José Francisco; Sutter, Daniel; Gazzani, Matteo; Mazzotti, Marco

    2017-01-01

    The chilled ammonia process (CAP) is considered one of the most promising alternatives to amine-based absorption processes for post-combustion carbon capture applied to power plants. This work provides an insight on the CAP adaptations required to meet the conditions found in the flue gas emitted in

  16. The passive response of the Integral Fast Reactor concept to the chilled inlet accident

    International Nuclear Information System (INIS)

    Vilim, R.B.

    1990-01-01

    Simple methods are described for bounding the passive response of a metal fueled liquid-metal cooled reactor to the chilled inlet accident. Calculation of these bounds for a prototype of the Integral Fast Reactor concept shows that failure limits --- eutectic melting, sodium boiling and fuel pin failure --- are not exceeded. 2 refs., 1 fig., 2 tabs

  17. Different responses of tobacco antioxidant enzymes to light and chilling stress

    NARCIS (Netherlands)

    Gechev, T; Willekens, H; Van Montagu, M; Inze, D; Van Camp, W; Toneva, [No Value; Minkov, [No Value

    The effect of elevated light treatment (25 degreesC, PPFD 360 mumol m(-2) sec(-1)) or chilling temperatures combined with elevated light (5 degreesC, PPFD 360 mumol m-2 sec-1) on the activity of six antioxidant enzymes, guaiacol peroxidases, and glutathione peroxidase (GPx, EC 1.11.1.9) protein

  18. Survivability of chilled water networks on board ships when using dincs

    NARCIS (Netherlands)

    Smit, C.S.

    2012-01-01

    Fast reaction is required when a chilled water distribution network on board a naval ship is damaged. Without immediate isolation of the leakage area, all water supply is lost soon, with immense consequences for the ship’s operational state. The only solution for that is using an automated recovery

  19. Avicennia germinans (black mangrove) vessel architecture is linked to chilling and salinity tolerance in the Gulf of Mexico

    Science.gov (United States)

    Madrid, Eric N.; Armitage, Anna R.; López-Portillo, Jorge

    2014-01-01

    Over the last several decades, the distribution of the black mangrove Avicennia germinans in the Gulf of Mexico has expanded, in part because it can survive the occasional freeze events and high soil salinities characteristic of the area. Vessel architecture may influence mangrove chilling and salinity tolerance. We surveyed populations of A. germinans throughout the Gulf to determine if vessel architecture was linked to field environmental conditions. We measured vessel density, hydraulically weighted vessel diameter, potential conductance capacity, and maximum tensile fracture stress. At each sampling site we recorded mangrove canopy height and soil salinity, and determined average minimum winter temperature from archived weather records. At a subset of sites, we measured carbon fixation rates using a LI-COR 6400XT Portable Photosynthesis System. Populations of A. germinans from cooler areas (Texas and Louisiana) had narrower vessels, likely reducing the risk of freeze-induced embolisms but also decreasing water conductance capacity. Vessels were also narrower in regions with high soil salinity, including Texas, USA and tidal flats in Veracruz, Mexico. Vessel density did not consistently vary with temperature or soil salinity. In abiotically stressful areas, A. germinans had a safe hydraulic architecture with narrower vessels that may increase local survival. This safe architecture appears to come at a substantial physiological cost in terms of reduction in conductance capacity and carbon fixation potential, likely contributing to lower canopy heights. The current distribution of A. germinans in the Gulf is influenced by the complex interplay between temperature, salinity, and vessel architecture. Given the plasticity of A. germinans vessel characters, it is likely that this mangrove species will be able to adapt to a wide range of potential future environmental conditions, and continue its expansion in the Gulf of Mexico in response to near-term climate change

  20. Avicennia germinans (black mangrove vessel architecture is linked to chilling and salinity tolerance in the Gulf of Mexico

    Directory of Open Access Journals (Sweden)

    Eric N Madrid

    2014-09-01

    Full Text Available Over the last several decades, the distribution of the black mangrove Avicennia germinans in the Gulf of Mexico has expanded, in part because it can survive the occasional freeze events and high soil salinities characteristic of the area. Vessel architecture may influence mangrove chilling and salinity tolerance. We surveyed populations of A. germinans throughout the Gulf to determine if vessel architecture was linked to field environmental conditions. We measured vessel density, hydraulically weighted vessel diameter, potential conductance capacity, and maximum tensile fracture stress. At each sampling site we recorded mangrove canopy height and soil salinity, and determined average minimum winter temperature from archived weather records. At a subset of sites, we measured carbon fixation rates using a LI-COR 6400XT Portable Photosynthesis System. Populations of A. germinans from cooler areas (Texas and Louisiana had narrower vessels, likely reducing the risk of freeze-induced embolisms but also decreasing water conductance capacity. Vessels were also narrower in regions with high soil salinity, including Texas, USA and tidal flats in Veracruz, Mexico. Vessel density did not consistently vary with temperature or soil salinity. In abiotically stressful areas, A. germinans had a safe hydraulic architecture with narrower vessels that may increase local survival. This safe architecture appears to come at a substantial physiological cost in terms of reduction in conductance capacity and carbon fixation potential, likely contributing to lower canopy heights. The current distribution of A. germinans in the Gulf is influenced by the complex interplay between temperature, salinity, and vessel architecture. Given the plasticity of A. germinans vessel characters, it is likely that this mangrove species will be able to adapt to a wide range of potential future environmental conditions, and continue its expansion in the Gulf of Mexico in response to near

  1. Study of a two-pipe chilled beam system for both cooling and heating of office buildings

    Energy Technology Data Exchange (ETDEWEB)

    Norouzi, R. [Univ. of Boraes, Boraes (Sweden); Hultmark, G. [Lindab Comfort A/S, Farum (Denmark); Afshari, A. (ed.); Bergsoee, N.C. [Aalborg Univ.. Statens Byggeforskningsinstitut (SBi), Copenhagen (Denmark)

    2013-05-15

    The main aim of this master thesis was to investigate possibilities and limitations of a new system in active chilled beam application for office buildings. Lindab Comfort A/S pioneered the presented system. The new system use two-pipe system, instead of the conventional active chilled beam four-pipe system for heating and cooling purposes. The Two-Pipe System which is studied in this project use high temperature cooling and low temperature heating with water temperatures of 20 deg. C to 23 deg. C, available for free most of the year. The system can thus take advantage of renewable energy. It was anticipated that a Two-Pipe System application enables transfer of energy from warm spaces to cold spaces while return flows, from cooling and heating beams, are mixed. BSim software was chosen as a simulation tool to model a fictional office building and calculate heating and cooling loads of the building. Moreover, the effect of using outdoor air as a cooling energy source (free cooling) is investigated through five possible scenarios in both the four pipe system and the Two-Pipe System. The calculations served two purposes. Firstly, the effect of energy transfer in the Two-Pipe System were calculated and compared with the four pipe system. Secondly, free cooling effect was calculated in the Two-Pipe System and compared with the four pipe system. The simulation results showed that the energy transfer, as an inherent characteristic in the Two-Pipe System, is able to reduce up to 3 % of annual energy use compared to the four pipe system. Furthermore, different free cooling applications in the Two-Pipe System and the four pipe system respectively showed that the Two-Pipe System requires 7-15 % less total energy than the four pipe system in one year. In addition, the Two-Pipe System can save 18-57 % of annual cooling energy when compared to the four pipe system. (Author)

  2. The role of gibberellins in improving the resistance of tebuconazole-coated maize seeds to chilling stress by microencapsulation.

    Science.gov (United States)

    Yang, Lijuan; Yang, Daibin; Yan, Xiaojing; Cui, Li; Wang, Zhenying; Yuan, Huizhu

    2016-11-07

    Chilling stress during germination often causes severe injury. In the present study, maize seed germination and shoot growth under chilling stress were negatively correlated with the dose of tebuconazole in an exponential manner as predicted by the model Y = A + B × e (-x/k) . Microencapsulation was an effective means of eliminating potential phytotoxic risk. The gibberellins (GAs) contents were higher after microencapsulation treatment than after conventional treatment when the dose of tebuconazole was higher than 0.12 g AI (active ingredient) kg -1 seed. Further analysis indicated that microencapsulation can stimulate ent-kaurene oxidase (KO) activity to some extent, whereas GA 3-oxidase (GA3ox) and GA 2-oxidase (GA2ox) activities remained similar to those in the control. Genes encoding GA metabolic enzymes exhibited different expression patterns. Transcript levels of ZmKO1 increased in the microcapsule treatments compared to the control. Even when incorporated into microcapsules, tebuconazole led to the upregulation of ZmGA3ox1 at doses of less than 0.12 g AI kg -1 seed and to the upregulation of ZmGA3ox2 when the dose was higher than 0.12 g AI kg -1 seed. With increasing doses of microencapsulated tebuconazole, the transcript levels of ZmGA2ox4, ZmGA2ox5 and ZmGA2ox6 exhibited upward trends, whereas the transcript levels of ZmGA2ox7 exhibited a downward trend.

  3. The asymmetric effects of El Niño and La Niña on the East Asian winter monsoon and their simulation by CMIP5 atmospheric models

    Science.gov (United States)

    Guo, Zhun; Zhou, Tianjun; Wu, Bo

    2017-02-01

    El Niño-Southern Oscillation (ENSO) events significantly affect the year-by-year variations of the East Asian winter monsoon (EAWM). However, the effect of La Niña events on the EAWM is not a mirror image of that of El Niño events. Although the EAWM becomes generally weaker during El Niño events and stronger during La Niña winters, the enhanced precipitation over the southeastern China and warmer surface air temperature along the East Asian coastline during El Niño years are more significant. These asymmetric effects are caused by the asymmetric longitudinal positions of the western North Pacific (WNP) anticyclone during El Niño events and the WNP cyclone during La Niña events; specifically, the center of the WNP cyclone during La Niña events is westward-shifted relative to its El Niño counterpart. This central-position shift results from the longitudinal shift of remote El Niño and La Niña anomalous heating, and asymmetry in the amplitude of local sea surface temperature anomalies over the WNP. However, such asymmetric effects of ENSO on the EAWM are barely reproduced by the atmospheric models of Phase 5 of the Coupled Model Intercomparison Project (CMIP5), although the spatial patterns of anomalous circulations are reasonably reproduced. The major limitation of the CMIP5 models is an overestimation of the anomalous WNP anticyclone/cyclone, which leads to stronger EAWM rainfall responses. The overestimated latent heat flux anomalies near the South China Sea and the northern WNP might be a key factor behind the overestimated anomalous circulations.

  4. Modulation of adverse impact of chilling in Vicia faba L. by methyl jasmonate involves changes in antioxidant metabolism and metabolites

    International Nuclear Information System (INIS)

    Allah, E.F.; Alqarawi, A.A.; Rashed, S.A.A.

    2016-01-01

    We conducted experiments to assess the effect of chilling (10 degree C) stress on growth, nitrogen and antioxidant components of faba bean (Vicia faba L.) and the role of methyl jasmonate (MJ 25 meu M) in growth regulation and amelioration of chilling stress. Chilling temperature significantly reduced growth and pigment synthesis which was however significantly improved by application of MJ. Nodule growth, nitrogenase activity and nitrogen content were negatively affected by chilling and MJ application caused significant improvement in these attributes. Application of MJ significantly enhanced activity of antioxidant enzymes resulting in reduced oxidative damage. Chilling stressed plants exhibited higher lipid peroxidation and production of hydrogen peroxide. Ascorbic acid and phenol contents were observed to increase by 8.4% and 7.9% due to MJ providing strength to plants against chilling stress. In addition application of MJ was observed to maintain optimal levels of abscissic acid (ABA) and salicylic acid (SA) resulting in coordinated regulation of defence mechanisms against chilling stress. (author)

  5. A retrospective study of artificial insemination of 251 mares using chilled and fixed time frozen-thawed semen.

    Science.gov (United States)

    Crowe, C A M; Ravenhill, P J; Hepburn, R J; Shepherd, C H

    2008-09-01

    Historically, artificial insemination (AI) using frozen semen has been perceived to have poorer success rates and be more labour intensive than using chilled semen. A retrospective study was therefore conducted to compare the conception rate achieved by AI between chilled and frozen semen, using fixed time insemination protocols over 2 breeding seasons. Artificial insemination using chilled semen produces a higher conception rate than that achieved with frozen semen. Mares (n = 251) were inseminated with either chilled (n = 112) or frozen (n = 139) semen in the 2006 and 2007 northern hemisphere breeding season. Per rectum ultrasonography of the mare's reproductive tract determined the timing of insemination, and deslorelin acetate was used to induce ovulation. Chilled semen insemination was performed using a single preovulatory dose delivered into the uterine body. Frozen semen was administered as 2 doses (pre- and post ovulation) using a deep uterine insemination technique. Pregnancy was detected ultrasonographically at 15 days post insemination. Conception rates were compared using a Chi-squared test. Insemination with frozen semen produced a significantly (P = 0.022) higher seasonal conception rate (82.0%) than that achieved with chilled semen (69.6%). Insemination with frozen semen can achieve conception rates equal to those with chilled semen, enabling the mare owner a greater selection of stallions.

  6. Microbiological evaluation of chicken carcasses in an immersion chilling system with water renewal at 8 and 16 hours.

    Science.gov (United States)

    Souza, L C T; Pereira, J G; Spina, T L B; Izidoro, T B; Oliveira, A C; Pinto, J P A N

    2012-05-01

    Since 2004, Brazil has been the leading exporter of chicken. Because of the importance of this sector in the Brazilian economy, food safety must be ensured by control and monitoring of the production stages susceptible to contamination, such as the chilling process. The goal of this study was to evaluate changes in microbial levels on chicken carcasses and in chilling water after immersion in a chilling system for 8 and 16 h during commercial processing. An objective of the study was to encourage discussion regarding the Brazilian Ministry of Agriculture Livestock and Food Supply regulation that requires chicken processors to completely empty, clean, and disinfect each tank of the chilling system after every 8-h shift. Before and after immersion chilling, carcasses were collected and analyzed for mesophilic bacteria, Enterobacteriaceae, coliforms, and Escherichia coli. Samples of water from the chilling system were also analyzed for residual free chlorine. The results do not support required emptying of the chiller tank after 8 h; these tanks could be emptied after 16 h. The results for all carcasses tested at the 8- and 16-h time points indicated no significant differences in the microbiological indicators evaluated. These data provide both technical and scientific support for discussing changes in federal law regarding the management of immersion chilling water systems used as part of the poultry processing line.

  7. Contrasting effect of dark-chilling on chloroplast structure and arrangement of chlorophyll-protein complexes in pea and tomato : Plants with a different susceptibility to non-freezing temperature

    NARCIS (Netherlands)

    Garstka, Maciej; Venema, Jan Henk; Rumak, Izabela; Gieczewska, Katarzyna; Rosiak, Malgorzata; Koziol-Lipinska, Joanna; Kierdaszuk, Borys; Vredenberg, Wim J.; Mostowska, Agnieszka

    2007-01-01

    The effect of dark-chilling and subsequent photoactivation on chloroplast structure and arrangements of chlorophyll-protein complexes in thylakoid membranes was studied in chilling-tolerant (CT) pea and in chilling-sensitive (CS) tomato. Dark-chilling did not influence chlorophyll content and Chl

  8. Contrasting effect of dark-chilling on chloroplast structure and arrangement of chlorophyll-protein complexes in pea and tomato: plants with a different susceptibility to non-freezing temperature

    NARCIS (Netherlands)

    Garstka, M.; Venema, J.H.; Rumak, I.; Gieczewska, K.; Rosiak, M.; Koziol-Lipinska, J.; Vredenberg, W.J.; Mostowska, A.

    2007-01-01

    The effect of dark-chilling and subsequent photoactivation on chloroplast structure and arrangements of chlorophyll-protein complexes in thylakoid membranes was studied in chilling-tolerant (CT) pea and in chilling-sensitive (CS) tomato. Dark-chilling did not influence chlorophyll content and Chl

  9. TRANSCRIPTOME DYNAMICS IN MANGO FRUIT PEEL REVEALS MECHANISMS OF CHILLING STRESS

    Directory of Open Access Journals (Sweden)

    Velu Sivankalyani

    2016-10-01

    Full Text Available Cold storage is considered the most effective method for prolonging fresh produce storage. However, subtropical fruit is sensitive to cold. Symptoms of chilling injury in mango include red and black spots that start from discolored lenticels and develop into pitting. The response of ‘Keitt’ mango fruit to chilling stress was monitored by transcriptomic, physiological and microscopic analyses. Transcriptomic changes in the mango fruit peel were evaluated during optimal (12°C and suboptimal (5°C cold storage. Two days of chilling stress upregulated genes involved in the plant stress response, including those encoding transmembrane receptors, calcium-mediated signal transduction, NADPH oxidase, MAP kinases and WRKYs, which can lead to cell death. Indeed, cell death was observed around the discolored lenticels after 19 days of cold storage at 5°C. Localized cell death and cuticular opening in the lumen of discolored lenticels were correlated with increased general decay during shelf-life storage, possibly due to fungal penetration. We also observed increased phenolics accumulation around the discolored lenticels, which was correlated with the biosynthesis of phenylpropanoids that were probably transported from the resin ducts. Increased lipid peroxidation was observed during chilling injury by both the biochemical malondialdehyde method and a new non-destructive luminescent technology, correlated to upregulation of the α-linolenic acid oxidation pathway. Genes involved in sugar metabolism were also induced, possibly to maintain osmotic balance. This analysis provides an in-depth characterization of mango fruit response to chilling stress and could lead to the development of new tools, treatments and strategies to prolong cold storage of subtropical fruit.

  10. Learning through a Winter's Tale

    Science.gov (United States)

    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…

  11. Why do insects enter and recover from chill coma? Low temperature and high extracellular potassium compromises muscle function in Locusta migratoria

    DEFF Research Database (Denmark)

    Findsen, Anders; Pedersen, Thomas Holm; Petersen, Asbjørn G

    2014-01-01

    When exposed to low temperatures, many insect species enter a reversible comatose state (chill coma), which is driven by a failure of neuromuscular function. Chill coma and chill coma recovery have been associated with a loss and recovery of ion-homeostasis (particularly extracellular [K......+]) and accordingly onset of chill coma has been hypothesised to result from depolarization of membrane potential caused by loss of ion-homeostasis. Here we examined whether onset of chill coma is associated with a disturbance in ion balance by examining the correlation between disruption of ion homeostasis and onset...... of chill coma in locusts exposed to cold at varying rates of cooling. Chill coma onset temperature changed maximally 1°C under different cooling rates and marked disturbances of ion homeostasis were not observed at any of the cooling rates. In a second set of experiments we used isolated tibial muscle...

  12. Study of a Two-Pipe Chilled Beam System for both Cooling and Heating of Office Buildings

    DEFF Research Database (Denmark)

    Gordnorouzi, Rouzbeh; Hultmark, Göran; Afshari, Alireza

    Active chilled beam systems are used to provide heating and cooling in order to achieve comfortable thermal indoor climate. For heating and cooling applications, an active chilled beam has two water circuits comprising four pipes that supply warm and cold water respectively to the beam coil...... according to the space demand. Lindab Comfort A/S has introduced an active chilled beam system which has just one water circuit (two pipes) that is used for both heating and cooling. The concept is based on high temperature cooling and low temperature heating. In this study the energy saving potential...

  13. Validation of AquaCrop Model for Simulation of Winter Wheat Yield and Water Use Efficiency under Simultaneous Salinity and Water Stress

    OpenAIRE

    M. Mohammadi; B. Ghahraman; K. Davary; H. Ansari; A. Shahidi

    2016-01-01

    Introduction: FAO AquaCrop model (Raes et al., 2009a; Steduto et al., 2009) is a user-friendly and practitioner oriented type of model, because it maintains an optimal balance between accuracy, robustness, and simplicity; and it requires a relatively small number of model input parameters. The FAO AquaCrop model predicts crop productivity, water requirement, and water use efficiency under water-limiting and saline water conditions. This model has been tested and validated for different crops ...

  14. Chilling of dormant buds hyperinduces FLOWERING LOCUS T and recruits GA-inducible 1,3-beta-glucanases to reopen signal conduits and release dormancy in Populus.

    Science.gov (United States)

    Rinne, Päivi L H; Welling, Annikki; Vahala, Jorma; Ripel, Linda; Ruonala, Raili; Kangasjärvi, Jaakko; van der Schoot, Christiaan

    2011-01-01

    In trees, production of intercellular signals and accessibility of signal conduits jointly govern dormancy cycling at the shoot apex. We identified 10 putative cell wall 1,3-β-glucanase genes (glucan hydrolase family 17 [GH17]) in Populus that could turn over 1,3-β-glucan (callose) at pores and plasmodesmata (PD) and investigated their regulation in relation to FT and CENL1 expression. The 10 genes encode orthologs of Arabidopsis thaliana BG_ppap, a PD-associated glycosylphosphatidylinositol (GPI) lipid-anchored protein, the Arabidopsis PD callose binding protein PDCB, and a birch (Betula pendula) putative lipid body (LB) protein. We found that these genes were differentially regulated by photoperiod, by chilling (5°C), and by feeding of gibberellins GA(3) and GA(4). GA(3) feeding upregulated all LB-associated GH17s, whereas GA(4) upregulated most GH17s with a GPI anchor and/or callose binding motif, but only GA(4) induced true bud burst. Chilling upregulated a number of GA biosynthesis and signaling genes as well as FT, but not CENL1, while the reverse was true for both GA(3) and GA(4). Collectively, the results suggest a model for dormancy release in which chilling induces FT and both GPI lipid-anchored and GA(3)-inducible GH17s to reopen signaling conduits in the embryonic shoot. When temperatures rise, the reopened conduits enable movement of FT and CENL1 to their targets, where they drive bud burst, shoot elongation, and morphogenesis.

  15. 36 CFR 1002.19 - Winter activities.

    Science.gov (United States)

    2010-07-01

    ... RECREATION § 1002.19 Winter activities. (a) Skiing, snowshoeing, ice skating, sledding, innertubing, tobogganing and similar winter sports are prohibited on Presidio Trust roads and in parking areas open to...

  16. Classification guide: Sochi 2014 Paralympic Winter Games

    OpenAIRE

    2014-01-01

    The Sochi 2014 Paralympic Winter Games classification guide is designed to provide National Paralympic Committees (NPCs) and International Federations (IFs) with information about the classification policies and procedures that will apply to the Sochi 2014 Paralympic Winter Games.

  17. Essential Outdoor Sun Safety Tips for Winter

    Science.gov (United States)

    ... Weekend Warriors expand/collapse Vitamin D Essential Outdoor Sun Safety Tips for Winter Winter sports enthusiasts are ... skiing! Be Mindful of Time Spent in the Sun, Regardless of the Season If possible, ski early ...

  18. Transcriptional regulatory network triggered by oxidative signals configures the early response mechanisms of japonica rice to chilling stress

    KAUST Repository

    Yun, Kil-Young; Park, Myoung Ryoul; Mohanty, Bijayalaxmi; Herath, Venura; Xu, Fuyu; Mauleon, Ramil; Wijaya, Edward; Bajic, Vladimir B.; Bruskiewich, Richard; de los Reyes, Benildo G

    2010-01-01

    -plant level analyses established a holistic view of chilling stress response mechanism of japonica rice. Early response regulatory network triggered by oxidative signals is critical for prolonged survival under sub-optimal temperature. Integration of stress

  19. Cold Vacuum Drying (CVD) Facility Vacuum Purge System Chilled Water System Design Description. System 47-4

    International Nuclear Information System (INIS)

    IRWIN, J.J.

    2000-01-01

    This system design description (SDD) addresses the Vacuum Purge System Chilled Water (VPSCHW) system. The discussion that follows is limited to the VPSCHW system and its interfaces with associated systems. The reader's attention is directed to Drawings H-1-82162, Cold Vacuum Drying Facility Process Equipment Skid PandID Vacuum System, and H-1-82224, Cold Vacuum Drying Facility Mechanical Utilities Process Chilled Water PandID. Figure 1-1 shows the location and equipment arrangement for the VPSCHW system. The VPSCHW system provides chilled water to the Vacuum Purge System (VPS). The chilled water provides the ability to condense water from the multi-canister overpack (MCO) outlet gases during the MCO vacuum and purge cycles. By condensing water from the MCO purge gas, the VPS can assist in drying the contents of the MCO

  20. Leadership in American Indian Communities: Winter Lessons

    Science.gov (United States)

    Metoyer, Cheryl A.

    2010-01-01

    Winter lessons, or stories told in the winter, were one of the ways in which tribal elders instructed and directed young men and women in the proper ways to assume leadership responsibilities. Winter lessons stressed the appropriate relationship between the leader and the community. The intent was to remember the power and purpose of that…

  1. 46 CFR 45.73 - Winter freeboard.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Winter freeboard. 45.73 Section 45.73 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) LOAD LINES GREAT LAKES LOAD LINES Freeboards § 45.73 Winter freeboard. The minimum winter freeboard (fw) in inches is obtained by the formula: fw=f(s)+T s...

  2. Redox Signaling and CBF-Responsive Pathway Are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Science.gov (United States)

    Cheng, Fei; Lu, Junyang; Gao, Min; Shi, Kai; Kong, Qiusheng; Huang, Yuan; Bie, Zhilong

    2016-01-01

    Salicylic acid (SA) plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus). Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-α-aminooxy-β-phenylpropionic acid (AOPP) increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon. PMID:27777580

  3. Redox Signaling and CBF-Responsive Pathway are Involved in Salicylic Acid-Improved Photosynthesis and Growth under Chilling Stress in Watermelon

    Directory of Open Access Journals (Sweden)

    Fei Cheng

    2016-10-01

    Full Text Available Salicylic acid (SA plays an important role in plant response to abiotic stresses. This study investigated the potential role of SA in alleviating the adverse effects of chilling stress on photosynthesis and growth in watermelon (Citrullus lanatus. Chilling stress induced the simultaneous accumulation of free and conjugated SA in watermelon plants, and the chilling-induced SA production was attributed to the phenylalanine ammonia-lyase pathway. Applying SA at moderate concentrations induced chilling tolerance, whereas inhibition of SA biosynthesis by L-ɑ-aminooxy-β-phenylpropionic acid (AOPP increased the photooxidation of PS II under chilling stress in watermelon, resulting in reduced photosynthesis and growth. Chilling induced a transient increase in the ratios of reduced to oxidized glutathione and reduced ascorbate to dehydroascorbate. Then, the expression of antioxidant genes was upregulated, and the activities of antioxidant enzymes were enhanced. Furthermore, SA-induced chilling tolerance was associated with cellular glutathione and ascorbate homeostasis, which served as redox signals to regulate antioxidant metabolism under chilling stress. AOPP treatment stimulated the chilling-induced expression of cold-responsive genes, particularly via C-repeat binding factors CBF3 and CBF4. These results confirm the synergistic role of SA signaling and the CBF-dependent responsive pathway during chilling stress in watermelon.

  4. The Role of Left Hemispheric Structures for Emotional Processing as a Monitor of Bodily Reaction and Felt Chill - a Case-Control Functional Imaging Study.

    Science.gov (United States)

    Grunkina, Viktoria; Holtz, Katharina; Klepzig, Kai; Neubert, Jörg; Horn, Ulrike; Domin, Martin; Hamm, Alfons O; Lotze, Martin

    2016-01-01

    Background: The particular function of the left anterior human insula on emotional arousal has been illustrated with several case studies. Only after left hemispheric insula lesions, patients lose their pleasure in habits such as listening to joyful music. In functional magnetic resonance imaging studies (fMRI) activation in the left anterior insula has been associated with both processing of emotional valence and arousal. Tight interactions with different areas of the prefrontal cortex are involved in bodily response monitoring and cognitive appraisal of a given stimulus. Therefore, a large left hemispheric lesion including the left insula should impair the bodily response of chill experience (objective chill response) but leave the cognitive aspects of chill processing (subjective chill response) unaffected. Methods: We investigated a patient (MC) with a complete left hemispheric media cerebral artery stroke, testing fMRI representation of pleasant (music) and unpleasant (harsh sounds) chill response. Results: Although chill response to both pleasant and unpleasant rated sounds was confirmed verbally at passages also rated as chilling by healthy participants, skin conductance response was almost absent in MC. For a healthy control (HC) objective and subjective chill response was positively associated. Bilateral prefrontal fMRI-response to chill stimuli was sustained in MC whereas insula activation restricted to the right hemisphere. Diffusion imaging together with lesion maps revealed that left lateral tracts were completely damaged but medial prefrontal structures were intact. Conclusion: With this case study we demonstrate how bodily response and cognitive appraisal are differentially participating in the internal monitor of chill response.

  5. Chemical additive to enhance antimicrobial efficacy of chlorine and control cross-contamination during immersion chill of broiler carcasses.

    Science.gov (United States)

    Schambach, B T; Berrang, M E; Harrison, M A; Meinersmann, R J

    2014-09-01

    Immersion chilling of broiler carcasses can be a site for cross-contamination between the occasional highly contaminated carcass and those that are co-chilled. Chlorine is often used as an antimicrobial but can be overcome by organic material. A proprietary chlorine stabilizer (T-128) based on phosphoric acid-propylene glycol was tested as a chill tank additive in experiments simulating commercial broiler chilling. In bench-scale experiments, 0.5% T-128 was compared with plain water (control), 50 ppm of chlorine, and the combination of 0.5% T-128 with 50 ppm of chlorine to control transfer of Salmonella and Campylobacter from inoculated wing drummettes to co-chilled uninoculated drummettes. Both chlorine and T-128 lessened cross-contamination with Salmonella (P additional experiment demonstrated that the antimicrobial effect of T-128 was not due merely to a lower pH. In commercial broiler chilling, a pH close to 6.0 is preferred to maximize chlorine effectiveness, while maintaining water-holding capacity of the meat. In a set of pilot-scale experiments with T-128, a near-ideal pH of 6.3 was achieved by using tap water instead of the distilled water used in bench-scale experiments. Pilot-scale chill tanks were used to compare the combination of 0.5% T-128 and 50 ppm of chlorine with 50 ppm of plain chlorine for control of cross-contamination between whole carcasses inoculated with Salmonella and Campylobacter and co-chilled uninoculated carcasses. The T-128 treatment resulted in significantly less crosscontamination by either direct contact or water transfer with both organisms compared with plain chlorine treatment. T-128 may have use in commercial broiler processing to enhance the effectiveness of chlorine in processing water.

  6. Assessment of Five Chilling Tolerance Traits and GWAS Mapping in Rice Using the USDA Mini-Core Collection

    Directory of Open Access Journals (Sweden)

    Michael R. Schläppi

    2017-06-01

    Full Text Available Rice (Oryza sativa L. is often exposed to cool temperatures during spring planting in temperate climates. A better understanding of genetic pathways regulating chilling tolerance will enable breeders to develop varieties with improved tolerance during germination and young seedling stages. To dissect chilling tolerance, five assays were developed; one assay for the germination stage, one assay for the germination and seedling stage, and three for the seedling stage. Based on these assays, five chilling tolerance indices were calculated and assessed using 202 O. sativa accessions from the Rice Mini-Core (RMC collection. Significant differences between RMC accessions made the five indices suitable for genome-wide association study (GWAS based quantitative trait loci (QTL mapping. For young seedling stage indices, japonica and indica subspecies clustered into chilling tolerant and chilling sensitive accessions, respectively, while both subspecies had similar low temperature germinability distributions. Indica subspecies were shown to have chilling acclimation potential. GWAS mapping uncovered 48 QTL at 39 chromosome regions distributed across all 12 rice chromosomes. Interestingly, there was no overlap between the germination and seedling stage QTL. Also, 18 QTL and 32 QTL were in regions discovered in previously reported bi-parental and GWAS based QTL mapping studies, respectively. Two novel low temperature seedling survivability (LTSS–QTL, qLTSS3-4 and qLTSS4-1, were not in a previously reported QTL region. QTL with strong effect alleles identified in this study will be useful for marker assisted breeding efforts to improve chilling tolerance in rice cultivars and enhance gene discovery for chilling tolerance.

  7. Variation in chilling tolerance for photosynthesis and leaf extension growth among genotypes related to the C-4 grass Miscanthus xgiganteus

    Energy Technology Data Exchange (ETDEWEB)

    Glowacka, K; Adhikari, S; Peng, JH; Gifford, J; Juvik, JA; Long, SP; Sacks, EJ

    2014-09-08

    The goal of this study was to identify cold-tolerant genotypes within two species of Miscanthus related to the exceptionally chilling-tolerant C-4 biomass crop accession: M. xgiganteus 'Illinois' (Mxg) as well as in other Mxg genotypes. The ratio of leaf elongation at 10 degrees C/5 degrees C to that at 25 degrees C/25 degrees C was used to identify initially the 13 most promising Miscanthus genotypes out of 51 studied. Net leaf CO2 uptake (A(sat)) and the maximum operating efficiency of photosystem II (Phi(PSII)) were measured in warm conditions (25 degrees C/20 degrees C), and then during and following a chilling treatment of 10 degrees C/5 degrees C for 11 d. Accessions of M. sacchariflorus (Msa) showed the smallest decline in leaf elongation on transfer to chilling conditions and did not differ significantly from Mxg, indicating greater chilling tolerance than diploid M. sinensis (Msi). Msa also showed the smallest reductions in A(sat) and Phi(PSII), and greater chilling-tolerant photosynthesis than Msi, and three other forms of Mxg, including new triploid accessions and a hexaploid Mxg 'Illinois'. Tetraploid Msa 'PF30153' collected in Gifu Prefecture in Honshu, Japan did not differ significantly from Mxg 'Illinois' in leaf elongation and photosynthesis at low temperature, but was significantly superior to all other forms of Mxg tested. The results suggested that the exceptional chilling tolerance of Mxg 'Illinois' cannot be explained simply by the hybrid vigour of this intraspecific allotriploid. Selection of chilling-tolerant accessions from both of Mxg's parental species, Msi and Msa, would be advisable for breeding new highly chilling-tolerant Mxg genotypes.

  8. Winter to winter recurrence of atmospheric circulation anomalies over East Asia and its impact on winter surface air temperature anomalies.

    Science.gov (United States)

    Zhao, Xia; Yang, Guang

    2017-01-01

    The persistence of atmospheric circulation anomalies over East Asia shows a winter to winter recurrence (WTWR) phenomenon. Seasonal variations in sea level pressure anomalies and surface wind anomalies display significantly different characteristics between WTWR and non-WTWR years. The WTWR years are characterized by the recurrence of both a strong (weak) anomalous Siberian High and an East Asian winter monsoon over two successive winters without persistence through the intervening summer. However, anomalies during the non-WTWR years have the opposite sign between the current and ensuing winters. The WTWR of circulation anomalies contributes to that of surface air temperature anomalies (SATAs), which is useful information for improving seasonal and interannual climate predictions over East Asia and China. In the positive (negative) WTWR years, SATAs are cooler (warmer) over East Asia in two successive winters, but the signs of the SATAs are opposite in the preceding and subsequent winters during the non-WTWR years.

  9. Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling*#

    Science.gov (United States)

    Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

    2016-01-01

    Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H2O2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato’s response to chilling stress. PMID:27921397

  10. Nitric oxide induced by polyamines involves antioxidant systems against chilling stress in tomato (Lycopersicon esculentum Mill.) seedling.

    Science.gov (United States)

    Diao, Qian-Nan; Song, Yong-Jun; Shi, Dong-Mei; Qi, Hong-Yan

    Polyamines (PAs) and nitric oxide (NO) are vital signals in modulating plant response to abiotic stress. However, to our knowledge, studies on the relationship between NO and PAs in response to cold stress in tomato are limited. Accordingly, in this study, we investigated the effects of putrescine (Put) and spermidine (Spd) on NO generation and the function of Spd-induced NO in the tolerance of tomato seedling under chilling stress. Spd increased NO release via the nitric oxide synthase (NOS)-like and nitrate reductase (NR) enzymatic pathways in the seedlings, whereas Put had no such effect. Moreover, H 2 O 2 might act as an upstream signal to stimulate NO production. Both exogenous NO donor (sodium nitroprusside (SNP)) and Spd enhanced chilling tolerance in tomato, thereby protecting the photosynthetic system from damage. Compared to chilling treatment alone, Spd enhanced the gene expressions of superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX), and their enzyme activities in tomato leaves. However, a scavenger or inhibitor of NO abolished Spd-induced chilling tolerance and blocked the increased expression and activity due to Spd of these antioxidant enzymes in tomato leaves under chilling stress. The results showed that NO induced by Spd plays a crucial role in tomato's response to chilling stress.

  11. MYC cis-Elements in PsMPT Promoter Is Involved in Chilling Response of Paeonia suffruticosa.

    Directory of Open Access Journals (Sweden)

    Yuxi Zhang

    Full Text Available The MPT transports Pi to synthesize ATP. PsMPT, a chilling-induced gene, was previously reported to promote energy metabolism during bud dormancy release in tree peony. In this study, the regulatory elements of PsMPT promoter involved in chilling response were further analyzed. The PsMPT transcript was detected in different tree peony tissues and was highly expressed in the flower organs, including petal, stigma and stamen. An 1174 bp of the PsMPT promoter was isolated by TAIL-PCR, and the PsMPT promoter::GUS transgenic Arabidopsis was generated and analyzed. GUS staining and qPCR showed that the promoter was active in mainly the flower stigma and stamen. Moreover, it was found that the promoter activity was enhanced by chilling, NaCl, GA, ACC and NAA, but inhibited by ABA, mannitol and PEG. In transgenic plants harboring 421 bp of the PsMPT promoter, the GUS gene expression and the activity were significantly increased by chilling treatment. When the fragment from -421 to -408 containing a MYC cis-element was deleted, the chilling response could not be observed. Further mutation analysis confirmed that the MYC element was one of the key motifs responding to chilling in the PsMPT promoter. The present study provides useful information for further investigation of the regulatory mechanism of PsMPT during the endo-dormancy release.

  12. Effect of high pressure treatment on microbiological quality of Indian white prawn (Fenneropenaeus indicus) during chilled storage.

    Science.gov (United States)

    Ginson, J; Panda, Satyen Kumar; Bindu, J; Kamalakanth, C K; Srinivasa Gopal, T K

    2015-04-01

    High pressure treatment of 250 MPa for 6 min at 25 °C was applied to headless Indian white prawn (Fenneropenaeus indicus) to evaluate changes in microbiological characteristics of the species during chilled storage. Changes in load of mesophilic bacteria, psychrotrophic bacteria, proteolytic bacteria, Enterobacteriaceae, Pseudomonas spp., H2S producing bacteria, lactic acid bacteria, Brochothrix thermosphacta and yeast & mold were estimated in pressurized and un-pressurized samples during chilled storage. All microbes were reduced significantly after high pressure treatment and there was significant difference in microbial quality of control and high pressure treated samples in the entire duration of chilled storage (p high pressure treated samples. In high pressure treated sample, no lag phase (λ) was observed for psychrotrophic bacteria, H2S producing bacteria, B. thermosphacta, Pseudomonas spp. and lactic acid bacteria; however, other bacteria showed a reduced lag phase during chilled storage. Kinetic parameter such as specific growth rate (μmax) in high pressure treated samples was significantly reduced in most of the bacterial groups except for psychrotrophic bacteria, Enterobacteriaceae and lactic acid bacteria. Mesophilic bacterial count of control samples crossed the marginal limit of acceptability on 12th day and unacceptable limit on 18th day of storage, whereas high pressure treated samples never breached the acceptability limit during entire duration of chilled storage. The present study indicated that application of high pressure processing can be used to improve microbial quality of Indian white prawn and extend the chilled storage life. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Use of gamma irradiation for improving the hygienic quality of chilled chicken

    International Nuclear Information System (INIS)

    Radziah Ariffin; Foziah Ali; Shahrul Hizam Alias

    1996-01-01

    Fresh, chilled chicken carcasses were irradiated at 2.5 kGy and stored at 40 degree C. At intervals samples were withdrawn for microbial, chemical and sensory evaluation. Result showed that combination of a 2.5 kGy irradiation dose and storage at 4 degree C were adequate for a radicidised chicken process. Immediately after irradiation, the microbial spoilage was reduced by at least 4 log cycles. The carcasses were qf excellent quality for at least 16 days of storage and were free from Salmonella and other food pathogens. Changes in chemical composition (moisture, fat, protein, ash and amino acids) and sensory quality of chicken carcasses irradiated at 2.5 kGy were not significant. Therefore the dose of 2.5 kGy should be the target for chilled chicken irradiation process

  14. An operational experience with cooling tower water system in chilling plant

    International Nuclear Information System (INIS)

    Rajan, Manju B.; Roy, Ankan; Ravi, K.V.

    2015-01-01

    Cooling towers are popular in industries as a very effective evaporative cooling technology for air conditioning. Supply of chilled water to air conditioning equipments of various plant buildings and cooling tower water to important equipments for heat removal is the purpose of chilling plant at PRPD. The cooling medium used is raw water available at site. Water chemistry is maintained by make-up and blowdown. In this paper, various observations made during plant operation and equipment maintenance are discussed. The issues observed was scaling and algal growth affecting the heat transfer and availability of the equipment. Corrosion related issues were observed to be less significant. Scaling indices were calculated to predict the behavior. (author)

  15. Polyphenol oxidase and peroxidase expression in four pineapple varieties (Ananas comosus L.) after a chilling injury.

    Science.gov (United States)

    Raimbault, Astrid-Kim; Marie-Alphonsine, Paul-Alex; Horry, Jean-Pierre; Francois-Haugrin, Madlyn; Romuald, Karell; Soler, Alain

    2011-01-12

    Pineapple internal browning (IB) is a chilling injury that produces enzymatic browning associated with flesh translucency. Pineapple biodiversity allowed the investigation of how polyphenol oxidase (PPO) and peroxidase (POD) activities with their different isoforms are involved in the IB mechanism. Fruits of four varieties that expressed IB symptoms differently, Smooth Cayenne (SCay) and the hybrids MD2, Flhoran 41 (Flh 41), and Flhoran 53 (Flh 53), were stressed by cold. The susceptible varieties showed classical brown spots but different patterns of IB, whereas MD2 and controls showed no IB. Enzymatic activities were measured on fruit protein extracts and PPO and POD isoforms separated on mini-gels (PhastSystem). Only PPO activity was significantly enhanced in the presence of IB. Up to six PPO isoforms were identified in the susceptible varieties. PPO was barely detectable in the nonsusceptible variety MD2 and in controls. The number of PPO isoforms and the total PPO activity after chilling are varietal characteristics.

  16. Flow meter fault isolation in building central chilling systems using wavelet analysis

    International Nuclear Information System (INIS)

    Chen Youming; Hao Xiaoli; Zhang Guoqiang; Wang Shengwei

    2006-01-01

    This paper presents an approach to isolate flow meter faults in building central chilling systems. It mathematically explains the fault collinearity among the flow meters in central chilling systems and points out that the sensor validation index (SVI) used in principal component analysis (PCA) is incapable of isolating flow meter faults due to the fault collinearity. The wavelet transform is used to isolate the flow meter faults as a substitute for the SVI of PCA. This approach can identify various variations in measuring signals, such as ramp, step, discontinuity etc., due to the good property of the wavelet in local time-frequency. Some examples are given to demonstrate its ability of fault isolation for the flow meters

  17. Successful artificial insemination in the Asian elephant (Elephas maximus using chilled and frozen-thawed semen

    Directory of Open Access Journals (Sweden)

    Wongkalasin Warut

    2009-07-01

    Full Text Available Abstract Background Artificial insemination (AI using frozen-thawed semen is well established and routinely used for breeding in various mammalian species. However, there is no report of the birth of elephant calves following AI with frozen-thawed semen. The objective of the present study was to investigate the fertilizing ability of chilled and frozen-thawed semen in the Asian elephant following artificial insemination (AI. Methods Semen samples were collected by from 8 bulls (age range, 12-to 42-years by manual stimulation. Semen with high quality were either cooled to 4°C or frozen in liquid nitrogen (-196°C before being used for AI. Blood samples collected from ten elephant females (age range, 12-to 52-years were assessed for estrus cycle and elephants with normal cycling were used for AI. Artificial insemination series were conducted during 2003 to 2008; 55 and 2 AI trials were conducted using frozen-thawed and chilled semen, respectively. Pregnancy was detected using transrectal ultrasonography and serum progestagen measurement. Results One female (Khod inseminated with chilled semen became pregnant and gave birth in 2007. The gestation length was 663 days and the sex of the elephant calf was male. One female (Sao inseminated with frozen-thawed semen showed signs of pregnancy by increasing progestagen levels and a fetus was observed for 5 months by transrectal ultrasonography. Conclusion This is the first report showing pregnancy following AI with frozen-thawed semen in the Asian elephant. Successful AI in the Asian elephant using either chilled or frozen-thawed semen is a stepping stone towards applying this technology for genetic improvement of the elephant population.

  18. Should Workers Avoid Consumption of Chilled Fluids in a Hot and Humid Climate?

    Directory of Open Access Journals (Sweden)

    Matt B. Brearley

    2017-12-01

    Full Text Available Despite provision of drinking water as the most common method of occupational heat stress prevention, there remains confusion in hydration messaging to workers. During work site interactions in a hot and humid climate, workers commonly report being informed to consume tepid fluids to accelerate rehydration. When questioned on the evidence supporting such advice, workers typically cite that fluid absorption is delayed by ingestion of chilled beverages. Presumably, delayed absorption would be a product of fluid delivery from the gut to the intestines, otherwise known as gastric emptying. Regulation of gastric emptying is multifactorial, with gastric volume and beverage energy density the primary factors. If gastric emptying is temperature dependent, the impact of cooling is modest in both magnitude and duration (≤ 5 minutes due to the warming of fluids upon ingestion, particularly where workers have elevated core temperature. Given that chilled beverages are most preferred by workers, and result in greater consumption than warm fluids during and following physical activity, the resultant increased consumption of chilled fluids would promote gastric emptying through superior gastric volume. Hence, advising workers to avoid cool/cold fluids during rehydration appears to be a misinterpretation of the research. More appropriate messaging to workers would include the thermal benefits of cool/cold fluid consumption in hot and humid conditions, thereby promoting autonomy to trial chilled beverages and determine personal preference. In doing so, temperature-based palatability would be maximized and increase the likelihood of workers maintaining or restoring hydration status during and after their work shift. Keywords: Fluid consumption, gastric emptying, hot and humid conditions, hydration, occupational

  19. Dual roles for hepatic lectin receptors in the clearance of chilled platelets

    DEFF Research Database (Denmark)

    Rumjantseva, Viktoria; Grewal, Prabhjit K; Wandall, Hans H

    2009-01-01

    -GlcNAc moieties by galactosylation prevents clearance of short-term-cooled platelets, this strategy is ineffective after prolonged refrigeration. We report here that prolonged refrigeration increased the density and concentration of exposed galactose residues on platelets such that hepatocytes, through Ashwell-Morell...... transfusion. Inhibition of chilled platelet clearance by both beta(2) integrin and Ashwell-Morell receptors may afford a potentially simple method for storing platelets in the cold....

  20. Transcriptome Dynamics in Mango Fruit Peel Reveals Mechanisms of Chilling Stress

    Science.gov (United States)

    Sivankalyani, Velu; Sela, Noa; Feygenberg, Oleg; Zemach, Hanita; Maurer, Dalia; Alkan, Noam

    2016-01-01

    Cold storage is considered the most effective method for prolonging fresh produce storage. However, subtropical fruit is sensitive to cold. Symptoms of chilling injury (CI) in mango include red and black spots that start from discolored lenticels and develop into pitting. The response of ‘Keitt’ mango fruit to chilling stress was monitored by transcriptomic, physiological, and microscopic analyses. Transcriptomic changes in the mango fruit peel were evaluated during optimal (12°C) and suboptimal (5°C) cold storage. Two days of chilling stress upregulated genes involved in the plant stress response, including those encoding transmembrane receptors, calcium-mediated signal transduction, NADPH oxidase, MAP kinases, and WRKYs, which can lead to cell death. Indeed, cell death was observed around the discolored lenticels after 19 days of cold storage at 5°C. Localized cell death and cuticular opening in the lumen of discolored lenticels were correlated with increased general decay during shelf-life storage, possibly due to fungal penetration. We also observed increased phenolics accumulation around the discolored lenticels, which was correlated with the biosynthesis of phenylpropanoids that were probably transported from the resin ducts. Increased lipid peroxidation was observed during CI by both the biochemical malondialdehyde method and a new non-destructive luminescent technology, correlated to upregulation of the α-linolenic acid oxidation pathway. Genes involved in sugar metabolism were also induced, possibly to maintain osmotic balance. This analysis provides an in-depth characterization of mango fruit response to chilling stress and could lead to the development of new tools, treatments and strategies to prolong cold storage of subtropical fruit. PMID:27812364

  1. Effect of electron beam irradiation on quality of fresh chilled pork

    International Nuclear Information System (INIS)

    Shang Yibin; Gao Meixu; Li Shurong; Pei Ying; Wang Zhidong

    2013-01-01

    The effects of electron beam irradiation on nutrient quality, lipid oxidation and sensory quality of fresh chilled pork were investigated. Fresh chilled pork whose fat to muscle ratio was 1 : 6 was grounded and packaged, and then irradiated at doses of 0, 2.0, 3.8, 6.2, 8.3 and 10.5 kGy. The contents of fat andprotein, chromaticity, sensory characteristics, lipid oxidation index of TBARS value, POV, diene value of irradiated and unirradiated samples were measured. The results showed that there were no significant differences (5% level) in content of proteinand fat between irradiated and control samples, but irradiation could significantly increase TBARS value and POV. EB irradiation enhanced the increase of total diene value. The samples treated with 3.8 and 6.2 kGy showed good color during storage. There were no significant differences in sensory characteristics among different EB doses. It is concluded that 4-6 kGy EB irradiation, which is effective for decontamination, shows no significant effect on qualities of fresh chilled pork. (authors)

  2. Proteomic evaluation of myofibrillar carbonylation in chilled fish mince and its inhibition by catechin.

    Science.gov (United States)

    Pazos, Manuel; Maestre, Rodrigo; Gallardo, José M; Medina, Isabel

    2013-01-01

    The present study investigates the susceptibility of individual myofibrillar proteins from mackerel (Scomber scombrus) mince to undergo carbonylation reactions during chilled storage, and the antioxidant capacity of (+)-catechin to prevent oxidative processes of proteins. The carbonylation of each particular protein was quantified by combining the labelling of protein carbonyls by fluorescein-5-thiosemicarbazide (FTSC) with 1-D or 2-D gel electrophoresis. Alpha skeletal actin, glycogen phosphorylase, unnamed protein product (UNP) similar to enolase, pyruvate kinase, isoforms of creatine kinase, aldolase A and an isoform of glyceraldehyde 3-phosphate dehydrogenase (G3PDH) showed elevated oxidation in chilled non-supplemented mince. Myosin heavy chain (MHC) was not carbonylated in chilled muscle, but an extensive MHC degradation was observed in those samples. The supplementation of catechin reduced protein oxidation and lipid oxidation in a concentration-dependent manner: control>25>100≈200ppm. Therefore, the highest catechin concentrations (100 and 200ppm) exhibited the strongest antioxidant activity. Catechin (200ppm) reduced significantly carbonylation of protein spots identified as glycogen phosphorylase, pyruvate kinase muscle isozyme, isoforms of creatine kinase. Conversely, catechin was ineffective to inhibit the oxidation of actin and UNP similar to enolase. These results draw attention to the inefficiency of catechin to prevent actin oxidation, in contrast to the extremely high efficiency of catechin in inhibiting oxidation of lipids and other proteins. Copyright © 2012 Elsevier Ltd. All rights reserved.

  3. Characterization of four Paenibacillus species isolated from pasteurized, chilled ready-to-eat meals.

    Science.gov (United States)

    Helmond, Mariette; Nierop Groot, Masja N; van Bokhorst-van de Veen, Hermien

    2017-07-03

    Food spoilage is often caused by microorganisms. The predominant spoilage microorganisms of pasteurized, chilled ready-to-eat (RTE) mixed rice-vegetable meals stored at 7°C were isolated and determined as Paenibacillus species. These sporeforming psychrotrophic bacteria are well adapted to grow in the starch-rich environment of pasteurized and chilled meals. Growth of the Paenibacillus isolates appeared to be delayed by decreased (5.5%, corresponding with an a w meal on spore inactivation, heat-inactivation kinetics were determined and D-values were calculated. According to these kinetics, pasteurization up to 90°C, necessary for inactivation of vegetative spoilage microorganisms and pathogens, does not significantly contribute to the inactivation of Paenibacillus spores in the meals. Furthermore, outgrowth of pasteurized spores was determined in the mixed rice-vegetable meal at several temperatures; P. terrae FBR-61 and P. pabuli FBR-75 isolates did not substantially increase in numbers during storage at 2°C, but had a significant increase within a month of storage at 4°C or within several days at 22°C. Overall, this work shows the importance of Paenibacillus species as spoilage microorganisms of pasteurized, chilled RTE meals and that the meals' matrix, processing conditions, and storage temperature are important hurdles to control microbial meal spoilage. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Low-temperature conditioning induces chilling tolerance in stored mango fruit.

    Science.gov (United States)

    Zhang, Zhengke; Zhu, Qinggang; Hu, Meijiao; Gao, Zhaoyin; An, Feng; Li, Min; Jiang, Yueming

    2017-03-15

    In this study, mango fruit were pre-treated with low-temperature conditioning (LTC) at 12°C for 24h, followed by refrigeration at 5°C for 25days before removal to ambient temperature (25°C) to investigate the effects and possible mechanisms of LTC on chilling injury (CI). The results showed that LTC effectively suppressed the development of CI in mango fruit, accelerated softening, and increased the soluble solids and proline content. Furthermore, LTC reduced electrolyte leakage, and levels of malondialdehyde, O 2 - and H 2 O 2 , maintaining membrane integrity. To reveal the molecular regulation of LTC on chilling tolerance in mango fruit, a C-repeat/dehydration-responsive element binding factor (CBF) gene, MiCBF1, was identified and its expression in response to LTC was examined using RT-qPCR. LTC resulted in a higher MiCBF1 expression. These findings suggest that LTC enhances chilling tolerance in mango fruit by inducing a series of physiological and molecular responses. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Analytical Method for Differentiation of Chilled and Frozen-Thawed Chicken Meat

    Directory of Open Access Journals (Sweden)

    Ivanova Ivelina

    2014-12-01

    Full Text Available : Chilled and frozen chicken breast and thigh meat were stored at +4±1 oC and - 20±1 oC, respectively. Maillard reaction between ribose and meat proteins of the chicken samples was initiated. The changes in the ribose-induced Maillard reaction rate during chilled and frozen storage of chicken meat were evaluated on the bases of corrected absorbance values (A420* and bovine melanoidin equivalent values (mg BME/g. Application of BME as a measure of ribose-induced Maillard reaction rate enables comparability of the data obtained by different spectrophotometers. It was found that the BME values of chicken meat frozen stored for more than 15 days were significantly (P<0.05 lower than BME values of chilled-stored samples. According to the suggested threshold limit values the chicken thigh and breast meat with BME values lower than 30 mg BME/g and 51 mg BME/g, respectively could be classified as frozen-thawed.

  6. Inertia gravity waves in the upper troposphere during the MaCWAVE winter campaign. Part II. Radar investigations and modelling studies

    Energy Technology Data Exchange (ETDEWEB)

    Serafimovich, A.; Zuelicke, C.; Hoffmann, P.; Peters, D.; Singer, W. [Leibniz-Inst. fuer Atmosphaerenphysik, Kuehlungsborn (Germany); Dalin, P. [Swedish Inst. of Space Physics, Kiruna (Sweden)

    2006-07-01

    We present an experimental and modelling study of a strong gravity wave event in the upper troposphere/lower stratosphere near the Scandinavian mountain ridge. Continuous VHP radar measurements during the MaCWAVE rocket and ground-based measurement campaign were performed at the Norwegian Andoya rocket range (ARR) near Andenes (69.3 N, 16 E) in January 2003. Detailed gravity wave investigations based on PSU/NCAR fifth-generation mesoscale model (MM5) data have been used for comparison with experimentally obtained results. The model data show the presence of a mountain wave and of an inertia gravity wave generated by a jet streak near the tropopause region. Temporal and spatial dependencies of jet induced inertia gravity waves with dominant observed periods of about 13 h and vertical wavelengths of {proportional_to}4.5-5 km are investigated with wavelet transform applied on radar measurements and model data. The jet induced wave packet is observed to move upstream and downward in the upper troposphere. The model data agree with the experimentally obtained results fairly well. Possible reasons for the observed differences, e.g. in the time of maximum of the wave activity, are discussed. Finally, the vertical fluxes of horizontal momentum are estimated with different methods and provide similar amplitudes. We found indications that the derived positive vertical flux of the horizontal momentum corresponds to the obtained parameters of the jet-induced inertia gravity wave, but only at the periods and heights of the strongest wave activity. (orig.)

  7. Tratamentos de pré-resfriamento e resfriamento sobre a qualidade de carne de peito de frango Pre-chilling and chilling treatments on poultry breast meat quality

    Directory of Open Access Journals (Sweden)

    Maria Cristina Bressan

    2004-06-01

    Full Text Available O total de 402 frangos foi processado em abatedouro comercial e submetido a seis tratamentos de resfriamento. Inicialmente as carcaças foram pré-resfriadas (PR por imersão em água e gelo, seguido de resfriamento (R a -35°C e estocagem a 4°C por 20 horas. Os tratamentos foram: a (0°C/30min, -35°C/3h e 15min, b (10°C/30min, 0°C/30min, -35°C/2h e 45 min, c (10°C/30min, -35°C/3h e 15min, d (20°C/30min, 0°C/30min, -35°C/2h e 45min, e (20°C/30min, -35°C/3h e 15min e F (20°C/30min, 0°C/3h e 15min. Temperaturas baixas utilizadas após a evisceração aceleraram a instalação do rigor em músculos pectoralis major (PM. Aos 45min post mortem carcaças sem PR (A ou PR a 10°C (B tiveram músculo PM com menor (PA total of 402 poultry was processed in a commercial poultry processing plant and submitted to six chilling treatments. Initially, the carcasses were chilled by immersion in water and ice, followed by cooling at -35°C or storage at 4°C for 20 hours. The treatments were: A (0°C/30min, -35°C/3h and 15min, B (10°C/30min, 0°C/30min, -35°C/2h and 45min, C (10°C/30min, -35°C/3h and 15min, D (20°C/30min, 0°C/30min, -35°C/2h and 45min, E (20°C/30min, -35°C/3h and 15min and F (20°C/30min, 0°C/3h and 15min. Low temperatures used after evisceration, accelerated the onset and resolution of rigor in pectoralis major (PM muscles. Up to 45 minutes post mortem, carcasses without pre-chilling (A or pre-chilled at 10°C (B, showed lower (P<0.001 pH values of 5.75 and 5.81, while in carcasses pre-chilled at 20°C (D, the values were higher, reaching 5.95. After 4h post mortem, the R values found in treatments A and B, with averages of 1.51 and 1.44, were higher (P<0.05 than the value of 1.32 found in treatment D. The luminescence (L* was influenced (P<0.001 by the treatments (in treatments A, B and C, the averages were 48.2, 47.7 and 47.6, while in treatments D and E, they were 45.5 and 45.7, respectively. The greater values for

  8. Communicating Certainty About Nuclear Winter

    Science.gov (United States)

    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

  9. An optimized data fusion method and its application to improve lateral boundary conditions in winter for Pearl River Delta regional PM2.5 modeling, China

    Science.gov (United States)

    Huang, Zhijiong; Hu, Yongtao; Zheng, Junyu; Zhai, Xinxin; Huang, Ran

    2018-05-01

    Lateral boundary conditions (LBCs) are essential for chemical transport models to simulate regional transport; however they often contain large uncertainties. This study proposes an optimized data fusion approach to reduce the bias of LBCs by fusing gridded model outputs, from which the daughter domain's LBCs are derived, with ground-level measurements. The optimized data fusion approach follows the framework of a previous interpolation-based fusion method but improves it by using a bias kriging method to correct the spatial bias in gridded model outputs. Cross-validation shows that the optimized approach better estimates fused fields in areas with a large number of observations compared to the previous interpolation-based method. The optimized approach was applied to correct LBCs of PM2.5 concentrations for simulations in the Pearl River Delta (PRD) region as a case study. Evaluations show that the LBCs corrected by data fusion improve in-domain PM2.5 simulations in terms of the magnitude and temporal variance. Correlation increases by 0.13-0.18 and fractional bias (FB) decreases by approximately 3%-15%. This study demonstrates the feasibility of applying data fusion to improve regional air quality modeling.

  10. Modeling the long-term effect of winter cover crops on nitrate transport in artificially drained fields across the Midwest U.S.

    Science.gov (United States)

    A fall-planted cover crop is a management practice with multiple benefits including reducing nitrate losses from artificially drained fields. We used the Root Zone Water Quality Model (RZWQM) to simulate the impact of a cereal rye cover crop on reducing nitrate losses from drained fields across five...

  11. Bayesian hierarchical modelling of continuous non-negative longitudinal data with a spike at zero: An application to a study of birds visiting gardens in winter.

    Science.gov (United States)

    Swallow, Ben; Buckland, Stephen T; King, Ruth; Toms, Mike P

    2016-03-01

    The development of methods for dealing with continuous data with a spike at zero has lagged behind those for overdispersed or zero-inflated count data. We consider longitudinal ecological data corresponding to an annual average of 26 weekly maximum counts of birds, and are hence effectively continuous, bounded below by zero but also with a discrete mass at zero. We develop a Bayesian hierarchical Tweedie regression model that can directly accommodate the excess number of zeros common to this type of data, whilst accounting for both spatial and temporal correlation. Implementation of the model is conducted in a Markov chain Monte Carlo (MCMC) framework, using reversible jump MCMC to explore uncertainty across both parameter and model spaces. This regression modelling framework is very flexible and removes the need to make strong assumptions about mean-variance relationships a priori. It can also directly account for the spike at zero, whilst being easily applicable to other types of data and other model formulations. Whilst a correlative study such as this cannot prove causation, our results suggest that an increase in an avian predator may have led to an overall decrease in the number of one of its prey species visiting garden feeding stations in the United Kingdom. This may reflect a change in behaviour of house sparrows to avoid feeding stations frequented by sparrowhawks, or a reduction in house sparrow population size as a result of sparrowhawk increase. © 2015 The Author. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Inertia gravity waves in the upper troposphere during the MaCWAVE winter campaign – Part II: Radar investigations and modelling studies

    Directory of Open Access Journals (Sweden)

    A. Serafimovich

    2006-11-01

    Full Text Available We present an experimental and modelling study of a strong gravity wave event in the upper troposphere/lower stratosphere near the Scandinavian mountain ridge. Continuous VHF radar measurements during the MaCWAVE rocket and ground-based measurement campaign were performed at the Norwegian Andoya Rocket Range (ARR near Andenes (69.3° N, 16° E in January 2003. Detailed gravity wave investigations based on PSU/NCAR Fifth-Generation Mesoscale Model (MM5 data have been used for comparison with experimentally obtained results. The model data show the presence of a mountain wave and of an inertia gravity wave generated by a jet streak near the tropopause region. Temporal and spatial dependencies of jet induced inertia gravity waves with dominant observed periods of about 13 h and vertical wavelengths of ~4.5–5 km are investigated with wavelet transform applied on radar measurements and model data. The jet induced wave packet is observed to move upstream and downward in the upper troposphere. The model data agree with the experimentally obtained results fairly well. Possible reasons for the observed differences, e.g. in the time of maximum of the wave activity, are discussed. Finally, the vertical fluxes of horizontal momentum are estimated with different methods and provide similar amplitudes. We found indications that the derived positive vertical flux of the horizontal momentum corresponds to the obtained parameters of the jet-induced inertia gravity wave, but only at the periods and heights of the strongest wave activity.

  13. A modeling study of the thermosphere-ionosphere interactions during the boreal winter and spring 2015-2016: Tidal and planetary-scale waves effect on the ionospheric structure.

    Science.gov (United States)

    Sassi, F.; McDonald, S. E.; McCormack, J. P.; Tate, J.; Liu, H.; Kuhl, D.

    2017-12-01

    The 2015-2016 boreal winter and spring is a dynamically very interesting time in the lower atmosphere: a minor high latitude stratospheric warming occurred in February 2016; an interrupted descent of the QBO was found in the tropical stratosphere; and a large warm ENSO took place in the tropical Pacific Ocean. The stratospheric warming, the QBO and ENSO are known to affect in different ways the meteorology of the upper atmosphere in different ways: low latitude solar tides and high latitude planetary-scale waves have potentially important implications on the structure of the ionosphere. In this study, we use global atmospheric analyses from a high-altitude version of the High-Altitude Navy Global Environmental Model (HA-NAVGEM) to constrain the meteorology of numerical simulations of the Specified Dynamics Whole Atmosphere Community Climate Model, extended version (SD-WACCM-X). We describe the large-scale behavior of tropical tides and mid-latitude planetary waves that emerge in the lower thermosphere. The effect on the ionosphere is captured by numerical simulations of the Navy Highly Integrated Thermosphere Ionosphere Demonstration System (Navy-HITIDES) that uses the meteorology generated by SD-WACCM-X to drive ionospheric simulations during this time period. We will analyze the impact of various dynamical fields on the zonal behavior of the ionosphere by selectively filtering the relevant dynamical modes.

  14. Expression of three sHSP genes involved in heat pretreatment-induced chilling tolerance in banana fruit.

    Science.gov (United States)

    He, Li-hong; Chen, Jian-ye; Kuang, Jian-fei; Lu, Wang-jin

    2012-07-01

    Banana fruit is highly susceptible to chilling injury. In previous research it was shown that heat pretreatment of banana fruit at 38 °C for 3 days before storage at a chilling temperature of 8 °C for 12 days prevented increases in visible chilling injury index, electrolyte leakage and malondialdehyde content and also decreases in lightness and chroma, indicating that heat pretreatment could effectively alleviate chilling injury of banana fruit. However, little is known about the role of small heat shock proteins (sHSPs) in postharvest chilling tolerance of banana fruit. In the present study, three cytosolic sHSP expression profiles in peel and pulp tissues of banana fruit during heat pretreatment and subsequent chilled storage (8 °C) were investigated in relation to heat pretreatment-induced chilling tolerance. Three full-length cDNAs of cytosolic sHSP genes, including two class I sHSP (CI sHSP) and one class II sHSP (CII sHSP) cDNAs, named Ma-CI sHSP1, Ma-CI sHSP2 and Ma-CII sHSP3 respectively, were isolated and characterised from harvested banana fruit. Accumulation of Ma-CI sHSP1 mRNA transcripts in peel and pulp tissues and Ma-CII sHSP3 mRNA transcripts in peel tissue increased during heat pretreatment. Expression of all three Ma-sHSP genes in peel and pulp tissues was induced during subsequent chilled storage. Furthermore, Ma-CI sHSP1 and Ma-CII sHSP3 mRNA transcripts in pulp tissue and Ma-CI sHSP2 mRNA transcripts in peel and pulp tissues were obviously enhanced by heat pretreatment at days 6 and 9 of subsequent chilled storage. These results suggested that heat pretreatment enhanced the expression of Ma-sHSPs, which might be involved in heat pretreatment-induced chilling tolerance of banana fruit. Copyright © 2012 Society of Chemical Industry.

  15. A model-based approach to adjust microwave observations for operational applications: results of a campaign at Munich Airport in winter 2011/2012

    Directory of Open Access Journals (Sweden)

    J. Güldner

    2013-10-01

    Full Text Available In the frame of the project "LuFo iPort VIS" which focuses on the implementation of a site-specific visibility forecast, a field campaign was organised to offer detailed information to a numerical fog model. As part of additional observing activities, a 22-channel microwave radiometer profiler (MWRP was operating at the Munich Airport site in Germany from October 2011 to February 2012 in order to provide vertical temperature and humidity profiles as well as cloud liquid water information. Independently from the model-related aims of the campaign, the MWRP observations were used to study their capabilities to work in operational meteorological networks. Over the past decade a growing quantity of MWRP has been introduced and a user community (MWRnet was established to encourage activities directed at the set up of an operational network. On that account, the comparability of observations from different network sites plays a fundamental role for any applications in climatology and numerical weather forecast. In practice, however, systematic temperature and humidity differences (bias between MWRP retrievals and co-located radiosonde profiles were observed and reported by several authors. This bias can be caused by instrumental offsets and by the absorption model used in the retrieval algorithms as well as by applying a non-representative training data set. At the Lindenberg observatory, besides a neural network provided by the manufacturer, a measurement-based regression method was developed to reduce the bias. These regression operators are calculated on the basis of coincident radiosonde observations and MWRP brightness temperature (TB measurements. However, MWRP applications in a network require comparable results at just any site, even if no radiosondes are available. The motivation of this work is directed to a verification of the suitability of the operational local forecast model COSMO-EU of the Deutscher Wetterdienst (DWD for the calculation

  16. Sensitivity of crop yield and N losses in winter wheat to changes in mean and variability of temperature and precipitation in Denmark using the FASSET model

    DEFF Research Database (Denmark)

    Patil, Raveendra Hanumantagoud; Lægdsmand, Mette; Olesen, Jørgen Eivind

    2012-01-01

    Sensitivity of wheat yield and soil nitrogen (N) losses to stepwise changes in means and variances of climatic variables were determined using the FASSET model. The LARS-WG was used to generate climate scenarios using observed climate data (1961–90) from two sites in Denmark, which differed...... loam. This study illustrates the importance of considering effects of changes to mean climatic factors, climatic variability and soil types on both crop yield and soil N losses....

  17. Modes of interannual variability in northern hemisphere winter atmospheric circulation in CMIP5 models: evaluation, projection and role of external forcing

    Science.gov (United States)

    Frederiksen, Carsten S.; Ying, Kairan; Grainger, Simon; Zheng, Xiaogu

    2018-04-01

    Models from the coupled model intercomparison project phase 5 (CMIP5) dataset are evaluated for their ability to simulate the dominant slow modes of interannual variability in the Northern Hemisphere atmospheric circulation 500 hPa geopotential height in the twentieth century. A multi-model ensemble of the best 13 models has then been used to identify the leading modes of interannual variability in components related to (1) intraseasonal processes; (2) slowly-varying internal dynamics; and (3) the slowly-varying response to external changes in radiative forcing. Modes in the intraseasonal component are related to intraseasonal variability in the North Atlantic, North Pacific and North American, and Eurasian regions and are little affected by the larger radiative forcing of the Representative Concentration Pathways 8.5 (RCP8.5) scenario. The leading modes in the slow-internal component are related to the El Niño-Southern Oscillation, Pacific North American or Tropical Northern Hemisphere teleconnection, the North Atlantic Oscillation, and the Western Pacific teleconnection pattern. While the structure of these slow-internal modes is little affected by the larger radiative forcing of the RCP8.5 scenario, their explained variance increases in the warmer climate. The leading mode in the slow-external component has a significant trend and is shown to be related predominantly to the climate change trend in the well mixed greenhouse gas concentration during the historical period. This mode is associated with increasing height in the 500 hPa pressure level. A secondary influence on this mode is the radiative forcing due to stratospheric aerosols associated with volcanic eruptions. The second slow-external mode is shown to be also related to radiative forcing due to stratospheric aerosols. Under RCP8.5 there is only one slow-external mode related to greenhouse gas forcing with a trend over four times the historical trend.

  18. Reduction of net primary productivity in southern China caused by abnormal low-temperature freezing in winter of 2008 detected by a remote sensing-driven ecosystem model

    Science.gov (United States)

    Ju, W.; Liu, Y.; Zhou, Y.; Zhu, G.

    2011-12-01

    Terrestrial carbon cycle is an important determinant of global climate change and affected by various factors, including climate, CO2 concentration, atmospheric nitrogen deposition and human activities. Extreme weather events can significantly regulate short-term even long-term carbon exchanges between terrestrial ecosystems and the atmosphere. During the period from the middle January to the middle February 2008, Southern China was seriously hit by abnormal low-temperature freezing, which caused serous damages to forests and crops. However, the reduction of net primary productivity (NPP) of terrestrial ecosystems caused by this extremely abnormal weather event has not been quantitatively investigated. In this study, the Boreal Ecosystem Productivity Simulator (BEPS) model was employed to assess the reduction of NPP in Southern China caused by the abnormal low-temperature freezing. Prior to the regional simulation, the BEPS model was validated using measured NPP in different ecosystems, demonstrating the ability of this model to simulate NPP reliably in China. Then, it was forced using meteorological data interpolated from observations of weather stations and leaf area index inversed from MODIS reflectance data to simulate national wide NPP at a 500 m resolution for the period from 2003 to 2008. The departures of NPP in 2008 from the means during 2003-2007 were used as the indicator of NPP reduction caused by the low-temperature freezing. It was found out that NPP in 2008 decreased significantly in forests of Southern China, especially in Guangdong, Fujian, Zhejiang, Guangxi, Jiangxi, and Hunan Provinces, in which the low-temperature freeing was more serious. The annul reduction of NPP was above 150 g C/m^2/yr in these areas. Key words: Net Primary Productivity, low-temperature freezing, BEPS model, MODIS Correspondence author: Weimin Ju Email:juweimin@nju.edu.cn

  19. Regulation of respiration and the oxygen diffusion barrier in soybean protect symbiotic nitrogen fixation from chilling-induced inhibition and shoots from premature senescence.

    Science.gov (United States)

    van Heerden, Philippus D R; Kiddle, Guy; Pellny, Till K; Mokwala, Phatlane W; Jordaan, Anine; Strauss, Abram J; de Beer, Misha; Schlüter, Urte; Kunert, Karl J; Foyer, Christine H

    2008-09-01

    Symbiotic nitrogen fixation is sensitive to dark chilling (7 degrees C-15 degrees C)-induced inhibition in soybean (Glycine max). To characterize the mechanisms that cause the stress-induced loss of nodule function, we examined nodule structure, carbon-nitrogen interactions, and respiration in two soybean genotypes that differ in chilling sensitivity: PAN809 (PAN), which is chilling sensitive, and Highveld Top (HT), which is more chilling resistant. Nodule numbers were unaffected by dark chilling, as was the abundance of the nitrogenase and leghemoglobin proteins. However, dark chilling decreased nodule respiration rates, nitrogenase activities, and NifH and NifK mRNAs and increased nodule starch, sucrose, and glucose in both genotypes. Ureide and fructose contents decreased only in PAN nodules. While the chilling-induced decreases in nodule respiration persisted in PAN even after return to optimal temperatures, respiration started to recover in HT by the end of the chilling period. The area of the intercellular spaces in the nodule cortex and infected zone was greatly decreased in HT after three nights of chilling, an acclimatory response that was absent from PAN. These data show that HT nodules are able to regulate both respiration and the area of the intercellular spaces during chilling and in this way control the oxygen diffusion barrier, which is a key component of the nodule stress response. We conclude that chilling-induced loss of symbiotic nitrogen fixation in PAN is caused by the inhibition of respiration coupled to the failure to regulate the oxygen diffusion barrier effectively. The resultant limitations on nitrogen availability contribute to the greater chilling-induced inhibition of photosynthesis in PAN than in HT.

  20. Learning at old age: a study on winter bees

    Directory of Open Access Journals (Sweden)

    Andreas Behrends

    2010-04-01

    Full Text Available Ageing is often accompanied by a decline in learning and memory abilities across the animal kingdom. Understanding age-related changes in cognitive abilities is therefore a major goal of current research. The honey bee is emerging as a novel model organism for age-related changes in brain function, because learning and memory can easily be studied in bees under controlled laboratory conditions. In addition, genetically similar workers naturally display life expectancies from six weeks (summer bees to six months (winter bees. We studied whether in honey bees, extreme longevity leads to a decline in cognitive functions. Six-month-old winter bees were conditioned either to odours or to tactile stimuli. Afterwards, long-term memory and discrimination abilities were analysed. Winter bees were kept under different conditions (flight /no flight opportunity to test for effects of foraging activity on learning performance. Despite their extreme age, winter bees did not display an age-related decline in learning or discrimination abilities, but had a slightly impaired olfactory long-term memory. The opportunity to forage indoors led to a slight decrease in learning performance. This suggests that in honey bees, unlike in most other animals, age per se does not impair associative learning. Future research will show which mechanisms protect winter bees from age-related deficits in learning.

  1. Winter distribution of Calanus finmarchicus in the Northeast Atlantic

    DEFF Research Database (Denmark)

    Heath, M.R.; Fraser, J.G.; Gislason, A.

    2000-01-01

    Data from plankton sampling and Optical Plankton Counter deployments during six cruises between December of 1994 and 1999 have been used to derive a composite three-dimensional distribution of the abundance of Calanus finmarchicus during winter (December-January) in the Norwegian Sea and Northeast...... Northeast Atlantic, the concentration of wintering animals is around 30% of that in the Norwegian Sea and the vertical distribution is more diffuse and on average deeper. Modelling studies have shown that the overwinter distribution and transport are key factors determining the spatial persistence of C...

  2. Short-term forecasting of the chloride content in the mineral waters of the Ustroń Health Resort using SARIMA and Holt-Winters models

    Directory of Open Access Journals (Sweden)

    Dąbrowska Dominika

    2015-12-01

    Full Text Available The Ustroń S.A. Health Resort (southern Poland uses iodide-bromide mineral waters taken from Middle and Upper Devonian limestones and dolomites with a mineralisation range of 110-130 g/dm3 for curative purposes. Two boreholes - U-3 and U3-A drilled in the early 1970s were exploited. The aim of this paper is to estimate changes in mineral water quality of the Ustroń Health Resort by taking into consideration chloride content in the water from the U-3 borehole. The data has included the results of monthly analyses of chlorides from 2005 to 2015 during the tests carried out by the Mining Department of the Health Resort. The triple exponential smoothing (ETS function and the Seasonal Autoregressive Integrated Moving Average (SARIMA method of modelling time series were used for the calculations. The ability to properly forecast mineral water quality can result in a good status of the exploitation borehole and a limited number of failures in the exploitation system. Because of the good management of health resorts, it is possible to acquire more satisfied customers. The main goal of the article involves the real-time forecast accuracy, obtained results show that the proposed methods are effective for such situations. Presented methods made it possible to obtain a 24-month point and interval forecast. The results of these analyses indicate that the chloride content is forecast to be in the range of 72 to 83 g/l from 2015 to 2017. While comparing the two methods of analysis, a narrower range of forecast values and, therefore, greater accuracy were obtained for the ETS function. The good performance of the ETS model highlights its utility compared with complicated physically based numerical models.

  3. The long-term effect of climate change on productivity of winter wheat in Denmark: a scenario analysis using three crop models

    DEFF Research Database (Denmark)

    Öztürk, Isik; Sharif, Behzad; Baby, Sanmohan

    2017-01-01

    ) A1B emission scenario for the 21st century using three process-based models; A 20-year set (1991–2010) of observed daily climate data from Aarslev, Denmark was used to form the baseline, from which the RCM data were generated. The simulation of crop growth was performed with increasing carbon...... dioxide (CO2) levels and under continuous mono-cropping system at different N input rates. Results indicated that grain yield and grain N will be reduced in the future despite increased CO2 concentration in the atmosphere. While the increased N input may increase yield, it will not increase grain N...

  4. The impact of winter heating on air pollution in China.

    Science.gov (United States)

    Xiao, Qingyang; Ma, Zongwei; Li, Shenshen; Liu, Yang

    2015-01-01

    Fossil-fuel combustion related winter heating has become a major air quality and public health concern in northern China recently. We analyzed the impact of winter heating on aerosol loadings over China using the MODIS-Aqua Collection 6 aerosol product from 2004-2012. Absolute humidity (AH) and planetary boundary layer height (PBL) -adjusted aerosol optical depth (AOD*) was constructed to reflect ground-level PM2.5 concentrations. GIS analysis, standard statistical tests, and statistical modeling indicate that winter heating is an important factor causing increased PM2.5 levels in more than three-quarters of central and eastern China. The heating season AOD* was more than five times higher as the non-heating season AOD*, and the increase in AOD* in the heating areas was greater than in the non-heating areas. Finally, central heating tend to contribute less to air pollution relative to other means of household heating.

  5. Winter therapy for the accelerators

    CERN Multimedia

    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...

  6. Identification of dehydrin-like proteins responsive to chilling in floral buds of blueberry (Vaccinium, section Cyanococcus).

    Science.gov (United States)

    Muthalif, M M; Rowland, L J

    1994-04-01

    The level of three major polypeptides of 65, 60, and 14 kD increased in response to chilling unit accumulation in floral buds of a woody perennial, blueberry (Vaccinium, section Cynaococcus). The level of the polypeptides increased most dramatically within 300 h of chilling and decreased to the prechilling level with the initiation of budbreak. Cold-hardiness levels were assessed for dormant buds of Vaccinium corymbosum and Vaccinium ashei after different chilling treatments until the resumption of growth. These levels coincided with the level of the chilling-responsive polypeptides. Like some other previously described cold-induced proteins in annual plants, the level of the chilling-induced polypeptides also increased in leaves in response to cold treatment; the chilling-induced polypeptides were heat stable, resisting aggregation after incubation at 95 degrees C for 15 min. By fractionating bud proteins first by isoelectric point (pI) and then by molecular mass, the pI values of the 65- and 60-kD polypeptides were found to be 7.5 to 8.0 and the pI value of the 14-kD polypeptide was judged to be 8.5. Purification of the 65- and 60-kD polypeptides, followed by digestion with endoproteinase Lys-C and sequencing of selected fragments, revealed similarities in amino acid composition between the 65- and 60-kD polypeptides and dehydrins. Indeed, antiserum to the lysine-rich consensus sequence EKKGIMDKIKEKLPG of dehydrin proteins cross-reacted to all three of the major chilling-responsive polypeptides of blueberry, identifying these as dehydrins or dehydrin-like proteins.

  7. Wintertime Overnight NOx Removal in a Southeastern United States Coal-fired Power Plant Plume: A Model for Understanding Winter NOx Processing and its Implications

    Science.gov (United States)

    Fibiger, Dorothy L.; McDuffie, Erin E.; Dubé, William P.; Aikin, Kenneth C.; Lopez-Hilfiker, Felipe D.; Lee, Ben H.; Green, Jaime R.; Fiddler, Marc N.; Holloway, John S.; Ebben, Carlena; Sparks, Tamara L.; Wooldridge, Paul; Weinheimer, Andrew J.; Montzka, Denise D.; Apel, Eric C.; Hornbrook, Rebecca S.; Hills, Alan J.; Blake, Nicola J.; DiGangi, Josh P.; Wolfe, Glenn M.; Bililign, Solomon; Cohen, Ronald C.; Thornton, Joel A.; Brown, Steven S.

    2018-01-01

    Nitric oxide (NO) is emitted in large quantities from coal-burning power plants. During the day, the plumes from these sources are efficiently mixed into the boundary layer, while at night, they may remain concentrated due to limited vertical mixing during which they undergo horizontal fanning. At night, the degree to which NO is converted to HNO3 and therefore unable to participate in next-day ozone (O3) formation depends on the mixing rate of the plume, the composition of power plant emissions, and the composition of the background atmosphere. In this study, we use observed plume intercepts from the Wintertime INvestigation of Transport, Emissions and Reactivity campaign to test sensitivity of overnight NOx removal to the N2O5 loss rate constant, plume mixing rate, background O3, and background levels of volatile organic compounds using a 2-D box model of power plant plume transport and chemistry. The factor that exerted the greatest control over NOx removal was the loss rate constant of N2O5. At the lowest observed N2O5 loss rate constant, no other combination of conditions converts more than 10% of the initial NOx to HNO3. The other factors did not influence NOx removal to the same degree.

  8. Winter warming from large volcanic eruptions

    Science.gov (United States)

    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.

  9. Use of Irradiation to Improve the Safety and Quality of Chilled Pad Thai (Stir Fry Rice Noodle with Dried Shrimp)

    International Nuclear Information System (INIS)

    Noomhorm, A.; Pungsawat, K.; Sirisoontaralak, P.; Vongsawasdi, P.

    2005-09-01

    Pad Thai, which is stir fried rice noodle with dried shrimp, was subjected to gamma irradiation. Two components (cooked rice noodle and spicy sauce with dried shrimp) were separately packed and inoculated with Listeria monocytogenes and Escherichia coli. D10 values of both pathogens were lower when pathogens were contaminated in cooked rice noodle. No survivors of both contaminated pathogens during 4 weeks of chilled storage when dose of 4 kGy was applied in the two components. After irradiation, texture of cooked rice noodle was softer and its color changed from white to yellow whereas redness of spicy sauce and dried shrimp decreased together with increase in pH of spicy sauce. During storage under chilled condition, all samples changed almost in the same pattern in term of harder texture and decrease in moisture content of cooked rice noodle, paler color of dried shrimp and spicy sauce and increase in pH of sauce. Panelists preferred non-irradiated Pad Thai at the beginning of storage but no difference was found at the end of storage. Dose of 4 kGy was recommended because chilled Pad Thai was free from pathogens, safe from microbial spoilage and acceptable sensory quality. Shelf life of chilled Pad Thai could be extended to more than 4 weeks compared to normal chilled ready meal, which has shelf life 5-7 days

  10. Immunodetection of nucleolar proteins and ultrastructure of nucleoli of soybean root meristematic cells treated with chilling stress and after recovery.

    Science.gov (United States)

    Stepiński, Dariusz

    2009-03-01

    The nucleolar proteins, fibrillarin and nucleophosmin, have been identified immunofluorescently in the root meristematic cells of soybean seedlings under varying experimental conditions: at 25 degrees C (control), chilling at 10 degrees C for 3 h and 4 days and recovery from the chilling stress at 25 degrees C. In each experimental variant, the immunofluorescence signals were present solely at the nucleolar territories. Fluorescent staining for both proteins was mainly in the shape of circular domains that are assumed to correspond to the dense fibrillar component of the nucleoli. The fewest fluorescent domains were observed in the nucleoli of chilled plants, and the highest number was observed in the plants recovered after chilling. This difference in the number of circular domains in the nucleoli of each variant may indicate various levels of these proteins in each variant. Both the number of circular domains and the level of these nucleolar proteins changed with changes in the transcriptional activity of the nucleoli, with the more metabolically active cell having higher numbers of active areas in the nucleolus and higher levels of nucleolar proteins, and conversely. Electron microscopic studies revealed differences in the ultrastructure of the nucleoli in all experimental variants and confirmed that the number of fibrillar centres surrounded by dense fibrillar component was the lowest in the nucleoli of chilled plants, and the highest in the nucleoli of recovered seedlings.

  11. Identification of two key genes controlling chill haze stability of beer in barley (Hordeum vulgare L).

    Science.gov (United States)

    Ye, Lingzhen; Huang, Yuqing; Dai, Fei; Ning, Huajiang; Li, Chengdao; Zhou, Meixue; Zhang, Guoping

    2015-06-11

    In bright beer, haze formation is a serious quality problem, degrading beer quality and reducing its shelf life. The quality of barley (Hordeum vulgare L) malt, as the main raw material for beer brewing, largely affects the colloidal stability of beer. In this study, the genetic mechanism of the factors affecting beer haze stability in barley was studied. Quantitative trait loci (QTL) analysis of alcohol chill haze (ACH) in beer was carried out using a Franklin/Yerong double haploid (DH) population. One QTL, named as qACH, was detected for ACH, and it was located on the position of about 108 cM in chromosome 4H and can explain about 20 % of the phenotypic variation. Two key haze active proteins, BATI-CMb and BATI-CMd were identified by proteomics analysis. Bioinformatics analysis showed that BATI-CMb and BATI-CMd had the same position as qACH in the chromosome. It may be deduced that BATI-CMb and BATI-CMd are candidate genes for qACH, controlling colloidal stability of beer. Polymorphism comparison between Yerong and Franklin in the nucleotide and amino acid sequence of BATI-CMb and BATI-CMd detected the corresponding gene specific markers, which could be used in marker-assisted selection for malt barley breeding. We identified a novel QTL, qACH controlling chill haze of beer, and two key haze active proteins, BATI-CMb and BATI-CMd. And further analysis showed that BATI-CMb and BATI-CMd might be the candidate genes associated with beer chill haze.

  12. Efficacy of chlorine dioxide against Listeria monocytogenes in brine chilling solutions.

    Science.gov (United States)

    Valderrama, W B; Mills, E W; Cutter, C N

    2009-11-01

    Chilled brine solutions are used by the food industry to rapidly cool ready-to-eat meat products after cooking and before packaging. Chlorine dioxide (ClO(2)) was investigated as an antimicrobial additive to eliminate Listeria monocytogenes. Several experiments were performed using brine solutions made of sodium chloride (NaCl) and calcium chloride (CaCl(2)) inoculated with L. monocytogenes and/or treated with 3 ppm of ClO(2). First, 10 and 20% CaCl(2) and NaCl solutions (pH 7.0) were inoculated with a five-strain cocktail of L. monocytogenes to obtain approximately 7 log CFU/ml and incubated 8 h at 0 degrees C. The results demonstrated that L. monocytogenes survived in 10% CaCl(2), 10 and 20% NaCl, and pure water. L. monocytogenes levels were reduced approximately 1.2 log CFU/ml in 20% CaCl(2). Second, inoculated ( approximately 7 log CFU/ml) brine solutions (10 and 20% NaCl and 10% CaCl(2)) treated with 3 ppm of ClO(2) resulted in a approximately 4-log reduction of the pathogen within 90 s. The same was not observed in a solution of 20% CaCl(2); further investigation demonstrated that high levels of divalent cations interfere with the disinfectant. Spent brine solutions from hot dog and ham chilling were treated with ClO(2) at concentrations of 3 or 30 ppm. At these concentrations, ClO(2) did not reduce L. monocytogenes. Removal of divalent cations and organic material in brine solutions prior to disinfection with ClO(2) should be investigated to improve the efficacy of the compound against L. monocytogenes. The information from this study may be useful to processing establishments and researchers who are investigating antimicrobials in chilling brine solutions.

  13. Response to chilling in cucumber (Cucumis sativus L. plants treated with triacontanol and Asahi SL.

    Directory of Open Access Journals (Sweden)

    Edward Borowski

    2012-12-01

    Full Text Available In pot experiments on cucumber cv. Śremski F1, the effect of short-term chilling on plants earlier treated with triacontanol (TRIA and Asahi SL was investigated. These plants were grown in a phytotron at an air temperature of 27/22°C (day/night, using fluorescent light with far flux density of 220 µmol × m-2 × s-1, with a photoperiod 16/8. At the 4th true leaf stage, the respective experimental series were sprayed with: 1 H2O - control, 2 TRIA 0.01, 3 TRIA 0.1, 4 TRIA 1.0 mg × dm-3, 5 Asahi SL 0.2, 6 Asahi SL 0.3%. After 24 hours one half of the plants from each experimental series was treated for a period of 3 days at a temperature of 12/6°C, with all the other growth conditions unchanged. The obtained results have shown that short-term chilling stress caused a significant increase in electrolyte leakage, free proline content and in the activity of guaiacol peroxidase in leaves, but a decrease in chlorophyll a+b content, stomatal conductance, transpiration, photosynthesis, leaf area and in the activity of catalase in leaves. The application of TRIA or ASAHI SL on leaves in the pre-stress period reduced the values of the traits which had been increased as a result of chilling and increased those which had reduced. Generally, TRIA was most effective at a concentration of 0.1 mg × dm-3, and Asahi SL at a concentration of 0.3%.

  14. Characteristics of Three Thioredoxin Genes and Their Role in Chilling Tolerance of Harvested Banana Fruit.

    Science.gov (United States)

    Wu, Fuwang; Li, Qing; Yan, Huiling; Zhang, Dandan; Jiang, Guoxiang; Jiang, Yueming; Duan, Xuewu

    2016-09-09

    Thioredoxins (Trxs) are small proteins with a conserved redox active site WCGPC and are involved in a wide range of cellular redox processes. However, little information on the role of Trx in regulating low-temperature stress of harvested fruit is available. In this study, three full-length Trx cDNAs, designated MaTrx6, MaTrx9 and MaTrx12, were cloned from banana (Musa acuminata) fruit. Phylogenetic analysis and protein sequence alignments showed that MaTrx6 was grouped to h2 type with a typical active site of WCGPC, whereas MaTrx9 and MaTrx12 were assigned to atypical cys his-rich Trxs (ACHT) and h3 type with atypical active sites of GCAGC and WCSPC, respectively. Subcellular localization indicated that MaTrx6 and MaTrx12 were located in the plasma membrane and cytoplasm, respectively, whereas MaTrx9 showed a dual cytoplasmic and chloroplast localization. Application of ethylene induced chilling tolerance of harvested banana fruit, whereas 1-MCP, an inhibitor of ethylene perception, aggravated the development of chilling injury. RT-qPCR analysis showed that expression of MaTrx12 was up-regulated and down-regulated in ethylene- and 1-MCP-treated banana fruit at low temperature, respectively. Furthermore, heterologous expression of MaTrx12 in cytoplasmic Trx-deficient Saccharomyces cerevisiae strain increased the viability of the strain under H₂O₂. These results suggest that MaTrx12 plays an important role in the chilling tolerance of harvested banana fruit, possibly by regulating redox homeostasis.

  15. Use of low-dose irradiation to enhance the safety and quality of chilled ready meals

    Energy Technology Data Exchange (ETDEWEB)

    Stewart, E M [Department of Food Science, Queen' s University Belfast (QUB) (United Kingdom); Patterson, M F [Food Science Division, Department of Agriculture and Rural Development (DARD), Belfast (United Kingdom)

    2002-07-01

    The market for 'cook-chill' ready meals has expanded significantly during the past ten years. This specific category of food has been defined as a catering system based on the full cooking of food followed by fast chilling and storage in controlled temperature conditions (0-3 deg. C) and subsequent thorough re-heating before consumption. Such meals cover a wide range of commodities including meat, poultry, fish, vegetables, pasta and desserts and are used at home by consumers and by the catering industry for use, for example, as hospital meals or meals-on-wheels. These products have a relatively short shelf-life with a recommended maximum shelf-life of 5 days at 0-3 deg. C including the day of cooking. In addition, there are other concerns with regard to microbiological quality, reduced sensory quality and decreased nutritive value. It has been suggested that low-dose irradiation could be used to extend the shelf-life of these products while at the same time reducing the risk of food poisoning. Research carried out at QUB and DARD has readily demonstrated that the safety and shelf-life of chilled ready meals consisting of meat (chicken, beef or pork) and certain vegetables (e.g. broccoli, carrots and roast potatoes) can be enhanced by irradiation doses of 2 or 3 kGy without having a detrimental effect on sensory or nutritional quality. To date, investigations have been limited to such traditional meals with no research being carried out on the more popular ready meals such as lasagna, cottage pies, curries, etc. which have a relatively short shelf-life upon purchase. It is therefore the objective of this work program to investigate the effect of low-dose irradiation (1-5 kGy) on the microbiological, sensory and nutritional quality of these meals and to determine if their overall quality can be enhanced.

  16. Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

    Science.gov (United States)

    Pedroso, D.L.; Dogenski, M.; Thomazini, M.; Heinemann, R.J.B.; Favaro-Trindade, C.S.

    2013-01-01

    In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01) and Lactobacillus acidophilus (LAC-04) were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF), and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (103 CFU/g). The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at −18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved. PMID:24516445

  17. Microencapsulation of Bifidobacterium animalis subsp. lactis and Lactobacillus acidophilus in cocoa butter using spray chilling technology

    Directory of Open Access Journals (Sweden)

    D.L. Pedroso

    2013-09-01

    Full Text Available In the present study, the cells of Bifidobacterium animalis subsp. lactis (BI-01 and Lactobacillus acidophilus (LAC-04 were encapsulated in cocoa butter using spray-chilling technology. Survival assays were conducted to evaluate the resistance of the probiotics to the spray-chilling process, their resistance to the simulated gastric and intestinal fluids (SGF and SIF, and their stability during 90 days of storage. The viability of the cells was not affected by microencapsulation. The free and encapsulated cells of B. animalis subsp. lactis were resistant to both SGF and SIF. The micro-encapsulated cells of L. acidophilus were more resistant to SGF and SIF than the free cells; the viability of the encapsulated cells was enhanced by 67%, while the free cells reached the detection limit of the method (10³ CFU/g. The encapsulated probiotics were unstable when they were stored at 20 °C. The population of encapsulated L. acidophilus decreased drastically when they were stored at 7 °C; only 20% of cells were viable after 90 days of storage. The percentage of viable cells of the encapsulated B. animalis subsp.lactis, however, was 72% after the same period of storage. Promising results were obtained when the microparticles were stored at -18 °C; the freeze granted 90 days of shelf life to the encapsulated cells. These results suggest that the spray-chilling process using cocoa butter as carrier protects L. acidophilus from gastrointestinal fluids. However, the viability of the cells during storage must be improved.

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

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Winter Harbor Lobster Boat Race, Winter Harbor, ME. 100.109 Section 100.109 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY REGATTAS AND MARINE PARADES SAFETY OF LIFE ON NAVIGABLE WATERS § 100.109 Winter Harbor...

  19. Controls on winter ecosystem respiration in temperate and boreal ecosystems

    Directory of Open Access Journals (Sweden)

    T. Wang

    2011-07-01

    Full Text Available Winter CO2 fluxes represent an important component of the annual carbon budget in northern ecosystems. Understanding winter respiration processes and their responses to climate change is also central to our ability to assess terrestrial carbon cycle and climate feedbacks in the future. However, the factors influencing the spatial and temporal patterns of winter ecosystem respiration (Reco of northern ecosystems are poorly understood. For this reason, we analyzed eddy covariance flux data from 57 ecosystem sites ranging from ~35° N to ~70° N. Deciduous forests were characterized by the highest winter Reco rates (0.90 ± 0.39 g C m−2 d−1, when winter is defined as the period during which daily air temperature remains below 0 °C. By contrast, arctic wetlands had the lowest winter Reco rates (0.02 ± 0.02 g C m−2 d−1. Mixed forests, evergreen needle-leaved forests, grasslands, croplands and boreal wetlands were characterized by intermediate winter Reco rates (g C m−2 d−1 of 0.70(±0.33, 0.60(±0.38, 0.62(±0.43, 0.49(±0.22 and 0.27(±0.08, respectively. Our cross site analysis showed that winter air (Tair and soil (Tsoil temperature played a dominating role in determining the spatial patterns of winter Reco in both forest and managed ecosystems (grasslands and croplands. Besides temperature, the seasonal amplitude of the leaf area index (LAI, inferred from satellite observation, or growing season gross primary productivity, which we use here as a proxy for the amount of recent carbon available for Reco in the subsequent winter, played a marginal role in winter CO2 emissions from forest ecosystems. We found that winter Reco sensitivity to temperature variation across space (

  20. Direct chill casting of aluminium alloys under electromagnetic interaction by permanent magnet assembly

    Science.gov (United States)

    Bojarevičs, Andris; Kaldre, Imants; Milgrāvis, Mikus; Beinerts, Toms

    2018-05-01

    Direct chill casting is one of the methods used in industry to obtain good microstructure and properties of aluminium alloys. Nevertheless, for some alloys grain structure is not optimal. In this study, we offer the use of electromagnetic interaction to modify melt convection near the solidification interface. Solidification under various electromagnetic interactions has been widely studied, but usually at low solidification velocity and high thermal gradient. This type of interaction may succeed fragmentation of dendrite arms and transport of solidification nuclei thus leading to improved material structure and properties. Realization of experimental small-scale crystallizer and electromagnetic system has been described in this article.

  1. The oxidative stability of chilled and frozen pilchards used as feed for captive southern bluefin tuna

    DEFF Research Database (Denmark)

    Fitz-Gerald, C.H.; Bremner, Allan

    1998-01-01

    . Vacuum packaging in a film of low permeability to oxygen was less effective than glazing and is not recommended due to cost. Pilchards in which oxidation had commenced before freezing continued to oxidise in frozen storage irrespective of whether they were glazed or vacuum packed. It was thus thoroughly...... demonstrated that the oil in the pilchards is very readily oxidised and careful handling, chilling, freezing and storage procedures need to be adopted to provide a product which is a nutritionally sound feed material for captive tuna. The demerit point scoring system was found to be a rapid evaluative...

  2. A consumer trial to assess the acceptability of an irradiated chilled ready meal

    International Nuclear Information System (INIS)

    Stevenson, M.H.; Stewart, E.M.; McAteer, N.J.

    1995-01-01

    One hundred and seven consumers assessed the sensory quality of a chilled irradiated (2 kGy) and non-irradiated ready meal, consisting of beef and gravy, Yorkshire pudding, carrot, broccoli and roast potato 4 days after treatment. The irradiated meal was moderately to very acceptable and was not significantly different to the non-irradiated meal. The beef and gravy component of the meal was most liked by consumers. Appearance and aroma appeared to be more important than flavour of texture in the overall assessment of the meals. (Author)

  3. A consumer trial to assess the acceptability of an irradiated chilled ready meal

    Energy Technology Data Exchange (ETDEWEB)

    Stevenson, M H [Queen` s University, Belfast (United Kingdom). Food Science Div.; [Queen` s University, Belfast (United Kingdom); Stewart, E M; McAteer, N J [Queen` s University, Belfast (United Kingdom). Dept. of Food Science

    1995-10-01

    One hundred and seven consumers assessed the sensory quality of a chilled irradiated (2 kGy) and non-irradiated ready meal, consisting of beef and gravy, Yorkshire pudding, carrot, broccoli and roast potato 4 days after treatment. The irradiated meal was moderately to very acceptable and was not significantly different to the non-irradiated meal. The beef and gravy component of the meal was most liked by consumers. Appearance and aroma appeared to be more important than flavour of texture in the overall assessment of the meals. (Author).

  4. Combining active chilled beams and air-cleaning technologies to improve the indoor climate in offices

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi; Afshari, Alireza; Bergsøe, Niels Christian

    2013-01-01

    This project is part of a long-term research programme to study the possibilities of using efficient air-cleaning technologies to improve the indoor air quality in buildings. The purpose of this part of the project was to study the energy-saving potential of combining the cooling and cleaning of ...... than 5 Pa (0.104 Ibf /ft2). Furthermore, the measurement results of the combined system showed that adding the filter accelerated the removal rate of the particles by 2 h-1. However, the efficiency of the chilled beam in exchanging heat was reduced by 38%....

  5. Combining active chilled beams and air cleaning technologies to improve indoor climate in offices

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi; Afshari, Alireza; Bergsøe, Niels Christian

    2012-01-01

    This project is part of a long-term research programme studying the possibilities of using efficient air cleaning technologies to improve the indoor air quality in buildings. The purpose of this part of the project is to study energy-saving potential by combining cooling and cleaning of air in of....... Furthermore, the measurement results of the combined system showed that adding the filter accelerated the removal rate of the particles by 2 (h-1). However, the efficiency of the chilled beam in exchanging the heat reduced by 38%....

  6. Impact of personalized ventilation combined with chilled ceiling on eye irritation symptoms

    DEFF Research Database (Denmark)

    Lipczynska, Aleksandra; Marcol, Bartosz; Kaczmarczyk, Jan

    2014-01-01

    Personalized ventilation (PV) improves inhaled air quality, because it provides fresh air to each workstation and directly to occupant’s breathing zone. The PV alone can be used for room ventilation when applied in conjunction with ceiling radiant cooling system, which removes sensible heat loads...... from the space. Combining PV with chilled ceiling may be an effective way to provide thermal comfort in rooms at air temperature higher than the recommended in the standards upper limit of 26°C (category II), because the operative temperature will be lower. However, combination of high air temperature...

  7. Contribution of polyamines metabolism and GABA shunt to chilling tolerance induced by nitric oxide in cold-stored banana fruit.

    Science.gov (United States)

    Wang, Yansheng; Luo, Zisheng; Mao, Linchun; Ying, Tiejin

    2016-04-15

    Effect of exogenous nitric oxide (NO) on polyamines (PAs) catabolism, γ-aminobutyric acid (GABA) shunt, proline accumulation and chilling injury of banana fruit under cold storage was investigated. Banana fruit treated with NO sustained lower chilling injury index than the control. Notably elevated nitric oxide synthetase activity and endogenous NO level were observed in NO-treated banana fruit. PAs contents in treated fruit were significantly higher than control fruit, due to the elevated activities of arginine decarboxylase and ornithine decarboxylase. NO treatment increased the activities of diamine oxidase, polyamine oxidase and glutamate decarboxylase, while reduced GABA transaminase activity to lower levels compared with control fruit, which resulted the accumulation of GABA. Besides, NO treatment upregulated proline content and significantly enhanced the ornithine aminotransferase activity. These results indicated that the chilling tolerance induced by NO treatment might be ascribed to the enhanced catabolism of PAs, GABA and proline. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. A novel aspartic acid protease gene from pineapple fruit (Ananas comosus): cloning, characterization and relation to postharvest chilling stress resistance.

    Science.gov (United States)

    Raimbault, Astrid-Kim; Zuily-Fodil, Yasmine; Soler, Alain; Cruz de Carvalho, Maria H

    2013-11-15

    A full-length cDNA encoding a putative aspartic acid protease (AcAP1) was isolated for the first time from the flesh of pineapple (Ananas comosus) fruit. The deduced sequence of AcAP1 showed all the common features of a typical plant aspartic protease phytepsin precursor. Analysis of AcAP1 gene expression under postharvest chilling treatment in two pineapple varieties differing in their resistance to blackheart development revealed opposite trends. The resistant variety showed an up-regulation of AcAP1 precursor gene expression whereas the susceptible showed a down-regulation in response to postharvest chilling treatment. The same trend was observed regarding specific AP enzyme activity in both varieties. Taken together our results support the involvement of AcAP1 in postharvest chilling stress resistance in pineapple fruits. Copyright © 2013 Elsevier GmbH. All rights reserved.

  9. Future bloom and blossom frost risk for Malus domestica considering climate model and impact model uncertainties.

    Science.gov (United States)

    Hoffmann, Holger; Rath, Thomas

    2013-01-01

    The future bloom and risk of blossom frosts for Malus domestica were projected using regional climate realizations and phenological ( = impact) models. As climate impact projections are susceptible to uncertainties of climate and impact models and model concatenation, the significant horizon of the climate impact signal was analyzed by applying 7 impact models, including two new developments, on 13 climate realizations of the IPCC emission scenario A1B. Advancement of phenophases and a decrease in blossom frost risk for Lower Saxony (Germany) for early and late ripeners was determined by six out of seven phenological models. Single model/single grid point time series of bloom showed significant trends by 2021-2050 compared to 1971-2000, whereas the joint signal of all climate and impact models did not stabilize until 2043. Regarding blossom frost risk, joint projection variability exceeded the projected signal. Thus, blossom frost risk cannot be stated to be lower by the end of the 21st century despite a negative trend. As a consequence it is however unlikely to increase. Uncertainty of temperature, blooming date and blossom frost risk projection reached a minimum at 2078-2087. The projected phenophases advanced by 5.5 d K(-1), showing partial compensation of delayed fulfillment of the winter chill requirement and faster completion of the following forcing phase in spring. Finally, phenological model performance was improved by considering the length of day.

  10. Interim Report 'Winter smog and traffic'.

    NARCIS (Netherlands)

    Bloemen, H.; Blom, T.; Bogaard, van den C.; Boluyt, N.; Bree, van L.; Brunekreef, B.; Hoek, G.; Zee, van der S.

    1994-01-01

    This report presents a halfway score of the research project "Winter smog and Traffic", one of the themes of the research programme "Air Pollution and Health". A state of the art is presented of the health effects associated with exposure to winter smog and of the toxicological effects caused by the

  11. Nuclear Winter: Scientists in the Political Arena

    Science.gov (United States)

    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.

  12. How to Have a Healthy Winter | Poster

    Science.gov (United States)

    Without a doubt, winter is here. Between the icy weather and the recent hustle and bustle of the holidays, everyone is at an increased risk of getting sick. With that in mind, Occupational Health Services has a few simple tips for staying healthy this winter.

  13. Chapter 7: Migration and winter ecology

    Science.gov (United States)

    Deborah M. Finch; Jeffrey F. Kelly; Jean-Luc E. Cartron

    2000-01-01

    The willow flycatcher (Empidonax traillii) is a Neotropical migrant that breeds in North America, but winters in Central and northern South America. Little specific information is known about migration and wintering ecology of the southwestern willow flycatcher (E. t. extimus) (Yong and Finch 1997). Our report applies principally...

  14. Effect of modified atmosphere and temperature abuse on the growth from spores and cereulide production of Bacillus weihenstephanensis in a cooked chilled meat sausage

    DEFF Research Database (Denmark)

    Thorsen, Line; Budde, Birgitte Bjørn; Koch, Anette Granly

    2009-01-01

    demonstrates that MAP can be used to inhibit growth of a psychrotolerant toxin producing Bacillus spp. during chill storage at 8 °C, and substantially reduce the risk of emetic food poisoning at abuse condition. Results are of relevance for improving safety of ready to eat processed chilled foods of extended...

  15. Analysis of low-temperature tolerance of a tomato (Lycopersicon esculentum) cybrid with chloroplasts from a more chilling-tolerant L-hirsutum accession

    NARCIS (Netherlands)

    Venema, JH; Eekhof, M; van Hasselt, PR

    Growth and photosynthesis of an alloplasmic tomato (cybrid), i.e. line AH47, containing the nuclear genome of the chilling-sensitive cytoplasmic albino mutant of L. esculentum Mill. 'Large Red Cherry' (LRC) and the plastome of a more chilling-tolerant high-altitude accession of the related wild

  16. Effect of methyl salicylate and methyl jasmonate pre-treatment on the volatile profile in tomato fruit subjected to chilling temperature

    Science.gov (United States)

    Tomato fruits exposed to chilling temperatures suffer aroma loss prior to visual chilling injury (CI) symptoms. Methyl salicylate (MeSA) and methyl jasmonate (MeJA) treatments were reported to alleviate the development of visual CI, however, it is unknown if the treatments alleviate internal CI in t...

  17. Chilling Prospect: Climate Change Effects of Mismanaged Refrigerants in China.

    Science.gov (United States)

    Duan, Huabo; Miller, T Reed; Liu, Gang; Zeng, Xianlai; Yu, Keli; Huang, Qifei; Zuo, Jian; Qin, Yufei; Li, Jinhui

    2018-06-05

    The global community has responded to the dual threats of ozone depletion and climate change from refrigerant emissions (e.g., chlorofluorocarbons, CFCs, and hydrofluorocarbons, HFCs) in refrigerators and air conditioners (RACs) by agreeing to phase out the production of the most damaging chemicals and replacing them with substitutes. Since these refrigerants are "banked" in products during their service life, they will continue to impact our environment for decades to come if they are released due to mismanagement at the end of life. Addressing such long-term impacts of refrigerants requires a dynamic understanding of the RACs' life cycle, which was largely overlooked in previous studies. Based on field surveys and a dynamic model, we reveal the lingering ozone depletion potential (ODP) and significant global warming potential (GWP) of scrap refrigerants in China, the world's largest producer (62%) and consumer (46%) of RACs in 2015, which comes almost entirely from air conditioners rather than refrigerators. If the use and waste management of RACs continue with the current trend, the total GWP of scrap refrigerants in China will peak by 2025 at a level of 135.2 ± 18.9 Mt CO 2 e (equal to approximately 1.2% ± 0.2% of China's total greenhouse gas emissions or the national total of either The Netherlands and Czech Republic in 2015). Our results imply an urgent need for improving the recycling and waste management of RACs in China.

  18. Transcriptome, carbohydrate, and phytohormone analysis of Petunia hybrida reveals a complex disturbance of plant functional integrity under mild chilling stress

    Science.gov (United States)

    Bauerfeind, Martin Andreas; Winkelmann, Traud; Franken, Philipp; Druege, Uwe

    2015-01-01

    Cultivation of chilling-tolerant ornamental crops at lower temperature could reduce the energy demands of heated greenhouses. To provide a better understanding of how sub-optimal temperatures (12°C vs. 16°C) affect growth of the sensitive Petunia hybrida cultivar ‘SweetSunshine Williams’, the transcriptome, carbohydrate metabolism, and phytohormone homeostasis were monitored in aerial plant parts over 4 weeks by use of a microarray, enzymatic assays and GC-MS/MS. The data revealed three consecutive phases of chilling response. The first days were marked by a strong accumulation of sugars, particularly in source leaves, preferential up-regulation of genes in the same tissue and down-regulation of several genes in the shoot apex, especially those involved in the abiotic stress response. The midterm phase featured a partial normalization of carbohydrate levels and gene expression. After 3 weeks of chilling exposure, a new stabilized balance was established. Reduced hexose levels in the shoot apex, reduced ratios of sugar levels between the apex and source leaves and a higher apical sucrose/hexose ratio, associated with decreased activity and expression of cell wall invertase, indicate that prolonged chilling induced sugar accumulation in source leaves at the expense of reduced sugar transport to and reduced sucrose utilization in the shoot. This was associated with reduced levels of indole-3-acetic acid and abscisic acid in the apex and high numbers of differentially, particularly up-regulated genes, especially in the source leaves, including those regulating histones, ethylene action, transcription factors, and a jasmonate-ZIM-domain protein. Transcripts of one Jumonji C domain containing protein and one expansin accumulated in source leaves throughout the chilling period. The results reveal a dynamic and complex disturbance of plant function in response to mild chilling, opening new perspectives for the comparative analysis of differently tolerant cultivars

  19. Estudio de la contaminación de las aguas del río Chillón

    OpenAIRE

    Reyes Cubas, Carmen Martha; Reyes Cubas, Carmen Martha

    2012-01-01

    En el Perú uno de los principales problemas ambientales, generalmente es ocasionado por contaminación de aguas y residuos sólidos. El estado y los gobiernos locales le han dado poca importancia a la calidad del agua y los esfuerzos por detener este problema aun siguen siendo incipientes. Las aguas del río Chillón han sufrido un incremento en la contaminación de sus aguas, la contaminación a lo largo de la Cuenca del río Chillón depende de una serie de factores entre los que se destacan: la in...

  20. Interaction of Polyamines, Abscisic Acid, Nitric Oxide, and Hydrogen Peroxide under Chilling Stress in Tomato (Lycopersicon esculentum Mill.) Seedlings

    OpenAIRE

    Diao, Qiannan; Song, Yongjun; Shi, Dongmei; Qi, Hongyan

    2017-01-01

    Polyamines (PAs) play a vital role in the responses of higher plants to abiotic stresses. However, only a limited number of studies have examined the interplay between PAs and signal molecules. The aim of this study was to elucidate the cross-talk among PAs, abscisic acid (ABA), nitric oxide (NO), and hydrogen peroxide (H2O2) under chilling stress conditions using tomato seedlings [(Lycopersicon esculentum Mill.) cv. Moneymaker]. The study showed that during chilling stress (4°C; 0, 12, and 2...

  1. Nuclear winter or nuclear fall?

    Science.gov (United States)

    Berger, André

    Climate is universal. If a major modern nuclear war (i.e., with a large number of small-yield weapons) were to happen, it is not even necessary to have a specific part of the world directly involved for there to be cause to worry about the consequences for its inhabitants and their future. Indeed, smoke from fires ignited by the nuclear explosions would be transported by winds all over the world, causing dark and cold. According to the first study, by Turco et al. [1983], air surface temperature over continental areas of the northern mid-latitudes (assumed to be the nuclear war theatre) would fall to winter levels even in summer (hence the term “nuclear winter”) and induce drastic climatic conditions for several months at least. The devastating effects of a nuclear war would thus last much longer than was assumed initially. Discussing to what extent these estimations of long-term impacts on climate are reliable is the purpose of this article.

  2. Exogenous melatonin improves corn (Zea mays L.) embryo proteome in seeds subjected to chilling stress.

    Science.gov (United States)

    Kołodziejczyk, Izabela; Dzitko, Katarzyna; Szewczyk, Rafał; Posmyk, Małgorzata M

    2016-04-01

    Melatonin (MEL; N-acetyl-5-methoxytryptamine) plays an important role in plant stress defense. Various plant species rich in this indoleamine have shown a higher capacity for stress tolerance. Moreover, it has great potential for plant biostimulation, is biodegradable and non-toxic for the environment. All this indicates that our concept of seed enrichment with exogenous MEL is justified. This work concerns the effects of corn (Zea mays L.) seed pre-sowing treatments supplemented with MEL. Non-treated seeds (nt), and those hydroprimed with water (H) or with MEL solutions 50 and 500 μM (HMel50, HMel500) were compared. Positive effects of seed priming are particularly apparent during germination under suboptimal conditions. The impact of MEL applied by priming on seed protein profiles during imbibition/germination at low temperature has not been investigated to date. In order to identify changes in the corn seed proteome after applying hydropriming techniques, purified protein extracts of chilling stressed seed embryos (14 days, 5°C) were separated by two-dimensional electrophoresis. Then proteome maps were graphically and statistically compared and selected protein spots were qualitatively analyzed using mass spectrometry techniques and identified. This study aimed to analyze the priming-induced changes in maize embryo proteome and at identifying priming-associated and MEL-associated proteins in maize seeds subjected to chilling. We attempt to explain how MEL expands plant capacity for stress tolerance. Copyright © 2016 Elsevier GmbH. All rights reserved.

  3. Dietary oxidized poultry offal fat: broiler performance and oxidative stability of thigh meat during chilled storage

    Directory of Open Access Journals (Sweden)

    AMC Racanicci

    2008-03-01

    Full Text Available Two experiments were conducted to evaluate the effects of dietary oxidized poultry offal fat on the performance of broilers and on the oxidative stability of dark chicken meat. One hundred and sixty male chicks were fed a corn-soybean meal diet containing 4% fresh or oxidized poultry fat from 10 to 47 days of age. Fresh fat was stored frozen until diets were produced, and oxidized fat was obtained by electrical heating (110 to 120 ºC. Birds were slaughtered at 47 days of age, and carcass characteristics were measured. Skinless and deboned thigh meat was stored chilled during 12 days, and samples were periodically collected to assess their quality and oxidative stability. Dietary oxidized fat did not affect bird performance or carcass characteristics. During chilled storage, meat color (L*, a* and b* was not affected by dietary treatments; however, TBARS (Thiobarbituric Acid Reactive Substances values were higher (P<0.05 in thigh meat from chickens fed the oxidized fat, indicating that oxidative stability was adversely affected.

  4. An application of the gas-fired chilling and heating units to domestic houses

    Energy Technology Data Exchange (ETDEWEB)

    Choi, J.H.; Yang, Y.M.; Chae, J.M.; Bang, H.S.; Kwon, O.B.; Yoo, S.I.; Kim, T.H. [R and D Center, Korea Gas Co. (Korea); Lee, T.W.; Kim, T.H.; Kim, B.H.; Hwang, I.J.; Kim, J.Y.; Kim, C.D.; Park, S.J. [Korea Institute of Construction Technology (Korea)

    1999-10-01

    Following researches and considerations were performed in this study for an efficient application of gas-fired chilling and heating units to the residential buildings. (1) Status of domestic cooling and heating for residential building. (2) Various introduction schemes of outdoor unit. (3) Design exclusive area for the gas appliance and installation of it. (4) Ventilation of exhaust gas and heat. (5) Prepare the installation specifications or standards for gas-fired chilling and heating units. (6) Design technique of plumbing for cooling and heating. (7) Evaluation of unit's capacity considering the thermal load of domestic buildings. (8) Cooling and heating system with the unit. (9) Fundamental test for evaluation of applicability. (10) Actual design and construction of experimental house for an application and a demonstration of the developed gas units. (11) Field test for cooling and heating. (12) Evaluation of economic efficiency. (13) Establish a business potential. (14) Establishment of legal and systematic support, energy rate. (15) Troubleshooting in the course of development and application of the new gas appliance. 41 refs., 214 figs., 52 tabs.

  5. Antimicrobial Activity of Various Plant Extracts on Pseudomonas Species Associated with Spoilage of Chilled Fish

    Directory of Open Access Journals (Sweden)

    Osan Bahurmiz

    2016-11-01

    Full Text Available The antimicrobial activity of various plant extracts on Pseudomonas bacteria isolated from spoiled chilled tilapia (Oreochromis sp. was evaluated in this study. In the first stage of this study, red tilapia was subjected to chilled storage (4°C for 3 weeks, and spoilage bacteria were isolated and identified from the spoiled fish. Pseudomonas was the dominant bacteria isolated from the spoiled fish and further identification revealed that P. putida, P. fluorescens and Pseudomonas spp. were the main species of this group. In the second stage, methanolic extracts of 15 selected plant species were screened for their antimicrobial activity, by agar disc diffusion method, against the Pseudomonas isolates. Results indicated that most of the extracts had different degrees of activity against the bacterial isolates. The strongest activity was exhibited by bottlebrush flower (Callistemon viminalis extract. This was followed by extracts from guava bark (Psidium guajava and henna leaf (Lawsonia inermis. Moderate antimicrobial activities were observed in extracts of clove (Syzygium aromaticum, leaf and peel of tamarind (Tamarindus indica, cinnamon bark (Cinnamomum zeylanicum, wild betel leaf (Piper sarmentosum and fresh thyme (Thymus spp.. Weak or no antimicrobial activity was observed from the remaining extracts. The potential antimicrobial activity shown by some plant extracts in this study could significantly contribute to the fish preservation.

  6. Quality and sensory acceptability of a chilled functional apple ready-dessert.

    Science.gov (United States)

    Keenan, D F; Brunton, N P; Gormley, T R; Butler, F

    2012-04-01

    An apple and dairy based ready-dessert with an added prebiotic was stored and chill temperatures and number of quality attributes were monitored during chill (4 °C) storage for 30 days. All ready-desserts were thermally processed by sous vide (P (90) > 10 min). The stability of the dairy component in ready-desserts was monitored by measuring volatile free fatty acids. Changes in these components were more evident in prebiotic-enriched samples compared to controls. However, no significant differences were observed over storage in control and prebiotic-enriched ready-desserts. This was supported by sensory analysis that showed no significant changes over storage in control or prebiotic-enriched samples. Of the other quality parameters, the addition of prebiotic inclusions resulted in lower L and b values and dry matter (p desserts. A decrease (p < 0.05) in flow behaviour (n) led to concomitant increases in consistency index (K) and complex modulus (G*) values in control samples.

  7. Alternative Layouts for the Carbon Capture with the Chilled Ammonia Process

    DEFF Research Database (Denmark)

    Valenti, Gianluca; Bonalumi, Davide; Fosbøl, Philip Loldrup

    2013-01-01

    Many alternatives are being investigated for the carbon capture, but none appears to have been proved as the choice for full-scale applications. This work considers the Chilled Ammonia Process for coal-fired Ultra Super Critical power plants. Three layouts are simulated with Aspen Plus and the Ex......Many alternatives are being investigated for the carbon capture, but none appears to have been proved as the choice for full-scale applications. This work considers the Chilled Ammonia Process for coal-fired Ultra Super Critical power plants. Three layouts are simulated with Aspen Plus...... substantially the electric loss due to stream extraction from the turbine. The simulations show that the net electric efficiency drops from 45.5% to 33.5-34.5%, the SPECCA index is 3.8-4.3 MJth kgCO2–1 and the heat duties are 2.7-2.9 MJth kgCO2–1. The performances may improve greatly upon optimization...

  8. Performance Monitoring of Chilled-Water Distribution Systems Using HVAC-Cx.

    Science.gov (United States)

    Ferretti, Natascha Milesi; Galler, Michael A; Bushby, Steven T

    2017-01-01

    In this research we develop, test, and demonstrate the newest extension of the software HVAC-Cx (NIST and CSTB 2014), an automated commissioning tool for detecting common mechanical faults and control errors in chilled-water distribution systems (loops). The commissioning process can improve occupant comfort, ensure the persistence of correct system operation, and reduce energy consumption. Automated tools support the process by decreasing the time and the skill level required to carry out necessary quality assurance measures, and as a result they enable more thorough testing of building heating, ventilating, and air-conditioning (HVAC) systems. This paper describes the algorithm, developed by National Institute of Standards and Technology (NIST), to analyze chilled-water loops and presents the results of a passive monitoring investigation using field data obtained from BACnet ® (ASHRAE 2016) controllers and presents field validation of the findings. The tool was successful in detecting faults in system operation in its first field implementation supporting the investigation phase through performance monitoring. Its findings led to a full energy retrocommissioning of the field site.

  9. Effect of Salicylic Acid on Prevention of Chilling Injury of Cherry Tomato (Lycopersicun esculentum cv. Messina(

    Directory of Open Access Journals (Sweden)

    hanifeh seyed hajizadeh

    2018-02-01

    Full Text Available Introduction: Fruits and vegetables play a major role in providing vitamins and minerals that are essential in the metabolism. In addition to providing vitamins and minerals compounds, they are called secondary metabolites. Tomatoes are one of the most vegetables in diets of people around the world. Low temperature stress associated with the production of reactive oxygen species causing damage can occur before or after harvest, farm, transportation, storage and marketing. Today, a greater emphasis is placed on post-harvest storage of agricultural products to increase productivity and make better use of labor resources, worker, energy and money, rather than an increase in production. One of the most promising treatments is the use of salicylic acid for prevention of the frost damage of post-harvest fruits and vegetables with different mechanisms such as increased enzymatic and non-enzymatic antioxidant system activity. Salicylic acid is known as a signal molecule in the induction defense mechanisms in plants. SA is a well-known phenol that can prevent ACO activity that is the direct precursor of ethylene and decreases Reactive Oxygen Species (ROS with increasing enzyme antioxidant activity. Salicylic acid is a natural phenolic compound known as a plant hormone having positive effect on storage life and quality of fruits. This study aimed to investigate the effects of pre- and post-harvest application of salicylic acid on antioxidant properties and quality of tomato and its effect was evaluated on prevention of chilling injury of cherry tomatoes during cold storage. Material and Methods: This research was conducted in a greenhouse of Horticulture Department of University of Maragheh. Treatments were included before harvest at fruit set stage with the control (distilled water and 0.75 mM salicylic acid spraying and after harvest, red ripened fruits were used for treatments control and immersion in 0.75 mM salicylic acid. Then all the treated fruits

  10. Combined Use of Landsat-8 and Sentinel-2A Images for Winter Crop Mapping and Winter Wheat Yield Assessment at Regional Scale

    Science.gov (United States)

    Skakun, Sergii; Vermote, Eric; Roger, Jean-Claude; Franch, Belen

    2017-01-01

    Timely and accurate information on crop yield and production is critical to many applications within agriculture monitoring. Thanks to its coverage and temporal resolution, coarse spatial resolution satellite imagery has always been a source of valuable information for yield forecasting and assessment at national and regional scales. With availability of free images acquired by Landsat-8 and Sentinel-2 remote sensing satellites, it becomes possible to provide temporal resolution of an image every 3-5 days, and therefore, to develop next generation agriculture products at higher spatial resolution (10-30 m). This paper explores the combined use of Landsat-8 and Sentinel-2A for winter crop mapping and winter wheat yield assessment at regional scale. For the former, we adapt a previously developed approach for the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument at 250 m resolution that allows automatic mapping of winter crops taking into account a priori knowledge on crop calendar. For the latter, we use a generalized winter wheat yield forecasting model that is based on estimation of the peak Normalized Difference Vegetation Index (NDVI) from MODIS image time-series, and further downscaled to be applicable at 30 m resolution. We show that integration of Landsat-8 and Sentinel-2A improves both winter crop mapping and winter wheat yield assessment. In particular, the error of winter wheat yield estimates can be reduced up to 1.8 times compared to using a single satellite.

  11. Combined Use of Landsat-8 and Sentinel-2A Images for Winter Crop Mapping and Winter Wheat Yield Assessment at Regional Scale

    Directory of Open Access Journals (Sweden)

    Sergii Skakun

    2017-05-01

    Full Text Available Timely and accurate information on crop yield and production is critical to many applications within agriculture monitoring. Thanks to its coverage and temporal resolution, coarse spatial resolution satellite imagery has always been a source of valuable information for yield forecasting and assessment at national and regional scales. With availability of free images acquired by Landsat-8 and Sentinel-2 remote sensing satellites, it becomes possible to provide temporal resolution of 3–5 days, and therefore, to develop next generation agriculture products at higher spatial resolution (10–30 m. This paper explores the combined use of Landsat-8 and Sentinel-2A for winter crop mapping and winter wheat yield assessment at regional scale. For the former, we adapt a previously developed approach for the Moderate Resolution Imaging Spectroradiometer (MODIS instrument at 250 m resolution that allows automatic mapping of winter crops taking into account a priori knowledge on crop calendar. For the latter, we use a generalized winter wheat yield forecasting model that is based on estimation of the peak Normalized Difference Vegetation Index (NDVI from MODIS image time-series, and further downscaled to be applicable at 30 m resolution. We show that integration of Landsat-8 and Sentinel-2A improves both winter crop mapping and winter wheat yield assessment. In particular, the error of winter wheat yield estimates can be reduced up to 1.8 times compared to using a single satellite.

  12. Seasonal overturning circulation in the Red Sea: 2. Winter circulation

    Science.gov (United States)

    Yao, Fengchao; Hoteit, Ibrahim; Pratt, Larry J.; Bower, Amy S.; Köhl, Armin; Gopalakrishnan, Ganesh; Rivas, David

    2014-04-01

    The shallow winter overturning circulation in the Red Sea is studied using a 50 year high-resolution MITgcm (MIT general circulation model) simulation with realistic atmospheric forcing. The overturning circulation for a typical year, represented by 1980, and the climatological mean are analyzed using model output to delineate the three-dimensional structure and to investigate the underlying dynamical mechanisms. The horizontal model circulation in the winter of 1980 is dominated by energetic eddies. The climatological model mean results suggest that the surface inflow intensifies in a western boundary current in the southern Red Sea that switches to an eastern boundary current north of 24°N. The overturning is accomplished through a cyclonic recirculation and a cross-basin overturning circulation in the northern Red Sea, with major sinking occurring along a narrow band of width about 20 km along the eastern boundary and weaker upwelling along the western boundary. The northward pressure gradient force, strong vertical mixing, and horizontal mixing near the boundary are the essential dynamical components in the model's winter overturning circulation. The simulated water exchange is not hydraulically controlled in the Strait of Bab el Mandeb; instead, the exchange is limited by bottom and lateral boundary friction and, to a lesser extent, by interfacial friction due to the vertical viscosity at the interface between the inflow and the outflow.

  13. Integrated RNA-Seq and sRNA-Seq Analysis Identifies Chilling and Freezing Responsive Key Molecular Players and Pathways in Tea Plant (Camellia sinensis)

    Science.gov (United States)

    Zheng, Chao; Zhao, Lei; Wang, Yu; Shen, Jiazhi; Zhang, Yinfei; Jia, Sisi; Li, Yusheng; Ding, Zhaotang

    2015-01-01

    Tea [Camellia sinensis (L) O. Kuntze, Theaceae] is one of the most popular non-alcoholic beverages worldwide. Cold stress is one of the most severe abiotic stresses that limit tea plants’ growth, survival and geographical distribution. However, the genetic regulatory network and signaling pathways involved in cold stress responses in tea plants remain unearthed. Using RNA-Seq, DGE and sRNA-Seq technologies, we performed an integrative analysis of miRNA and mRNA expression profiling and their regulatory network of tea plants under chilling (4℃) and freezing (-5℃) stress. Differentially expressed (DE) miRNA and mRNA profiles were obtained based on fold change analysis, miRNAs and target mRNAs were found to show both coherent and incoherent relationships in the regulatory network. Furthermore, we compared several key pathways (e.g., ‘Photosynthesis’), GO terms (e.g., ‘response to karrikin’) and transcriptional factors (TFs, e.g., DREB1b/CBF1) which were identified as involved in the early chilling and/or freezing response of tea plants. Intriguingly, we found that karrikins, a new group of plant growth regulators, and β-primeverosidase (BPR), a key enzyme functionally relevant with the formation of tea aroma might play an important role in both early chilling and freezing response of tea plants. Quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) analysis further confirmed the results from RNA-Seq and sRNA-Seq analysis. This is the first study to simultaneously profile the expression patterns of both miRNAs and mRNAs on a genome-wide scale to elucidate the molecular mechanisms of early responses of tea plants to cold stress. In addition to gaining a deeper insight into the cold resistant characteristics of tea plants, we provide a good case study to analyse mRNA/miRNA expression and profiling of non-model plant species using next-generation sequencing technology. PMID:25901577

  14. Chalillo chill

    Energy Technology Data Exchange (ETDEWEB)

    Loverock, K. [Waterloo Univ., ON (Canada)

    2002-03-31

    The proposed $44-million Chalillo dam project in the Macal River Valley of western Belize is being met with criticism from ecological scientists who claim the project is a threat to endangered wildlife in one of Central America's most ecologically sensitive areas. Despite the criticism, Fortis Inc., a Canadian power company based in St. John's Newfoundland along with the government of Belize, is pressing ahead with the proposal claiming that it will bring in foreign investment, help alleviate poverty and decrease dependence on power imports from Mexico. Belize currently gets its energy from the Mollejon dam, from diesel generators and from the Mexican power grid. The Chalillo dam will be 49.5 metres high and will flood about 20 kilometres up the Macal River valley, destroying about 800 hectares of prime valley habitat including parts of the Mountain Pine Ridge Forest Reserve, Chiquibul Forest Reserve and Chiquibul National Park. Its generating capacity is expected to be only 8 megawatts and critics doubt that it will generate much power during the dry season. The Macal River Valley is habitat to a range of threatened species including the rare scarlet macaw, Central American river otters, Morelet's crocodiles, Central American spider monkeys, tapirs, ocelots and jaguars. In addition, the flooding would destroy 2 Mayan ruins. Eighteen leading scientists and naturalists from around the world have joined forces to protest the project. Former project partner Duke Energy of the United States decided to withdraw from the project, but Fortis, which owns 68 per cent of Belize's national electricity utility, Belize Electricity Limited, is still pressing ahead. The Prime Minister of Belize does not think it is fair for environmental groups to criticize the project when their own countries have so many dams. An independent economic analysis has shown that the dam may be profitable for Fortis but economically detrimental for Belizeans. Critics say the power would be sold to Belize Electricity at 15 cents per kilowatt hour, nearly double the current cost of power imported from Mexico. Alternative domestic supply options include electricity from bagasse units which can generate power at about 11 cents per kilowatt hour. The Canadian International Development Agency (CIDA) contributed nearly half a million dollars to AMEC, a Canadian engineering firm, to ensure that a proper environmental assessment was carried out. Opponents say that while the assessment clearly recognizes the project would have adverse environmental effects, it includes inaccurate and misleading information on geology and hydrology. CIDA thinks it is unfortunate that the Belize government is not heeding the conclusion of the assessment, but that the decision is beyond CIDA's influence. 1 fig.

  15. 'Downward control' of the mean meridional circulation and temperature distribution of the polar winter stratosphere

    Science.gov (United States)

    Garcia, Rolando R.; Boville, Byron A.

    1994-01-01

    According to the 'downward control' principle, the extratropical mean vertical velocity on a given pressure level is approximately proportional to the meridional gradient of the vertically integrated zonal force per unit mass exerted by waves above that level. In this paper, a simple numerical model that includes parameterizations of both planetary and gravity wave breaking is used to explore the influence of gravity wave breaking in the mesosphere on the mean meridional circulation and temperature distribution at lower levels in the polar winter stratosphere. The results of these calculations suggest that gravity wave drag in the mesosphere can affect the state of the polar winter stratosphere down to altitudes below 30 km. The effect is most important when planetary wave driving is relatively weak: that is, during southern winter and in early northern winter. In southern winter, downwelling weakens by a factor of 2 near the stratospause and by 20% at 30 km when gravity wave drag is not included in the calculations. As a consequence, temperatures decrease considerably throughout the polar winter stratosphere (over 20 K above 40 km and as much as 8 K at 30 km, where the effect is enhanced by the long radiative relaxation timescale). The polar winter states obtained when gravity wave drag is omitted in this simple model resemble the results of simulations with some general circulation models and suggest that some of the shortcomings of the latter may be due to a deficit in mesospheric momentum deposition by small-scale gravity waves.

  16. [Morphophysiological and Behavioral Adaptations of Elk to Wintering].

    Science.gov (United States)

    Glushkov, V M; Kuznetsov, G V

    2015-01-01

    This paper studies morphometric parameters (body weight, weight of internal organs, body size, etc.) in 170 elk of various sex and age obtained in the Vyatka taiga area in winter. A number of physiological parameters (specific metabolism and thermal conductivity, heat loss rate, etc.) characterizing the metabolic rate and energy balance in the body were calculated for model animals (calf, male, and female). It is noted that in the transition from the first to the second half of winter the specific metabolism in model animals decreased from 20.6, 16.9, and 15.9 to 18.7, 15.4, and 14.5 kcal/(kg day), respectively. It is shown that changes in the rhythm of motor activity of elk are synchronized with the daily air temperature and the maximum flight distance depends on the amount of energy received by the body with food.

  17. A successful forecast of an El Nino winter

    International Nuclear Information System (INIS)

    Kerr, R.A.

    1992-01-01

    This year, for the first time, weather forecasters used signs of a warming in the tropical Pacific as the basis for a long-range prediction of winter weather patterns across the United States. Now forecasters are talking about the next step: stretching the lead time for such forecasts by a year or more. That seems feasible because although this Pacific warming was unmistakable by the time forecasters at the National Weather Service's Climate Analysis Center (CAC) in Camp Springs, Maryland, issued their winter forecast, the El Nino itself had been predicted almost 2 years in advance by a computer model. Next time around, the CAC may well be listening to the modelers and predicting El Nino-related patterns of warmth and flooding seasons in advance

  18. Use of electronic tongue for differentiation of tomato taste by cultivar, harvest maturity, and chilling or heating exposure

    Scien