WorldWideScience

Sample records for extremely cold temperatures

  1. Large reptiles and cold temperatures: Do extreme cold spells set distributional limits for tropical reptiles in Florida?

    Science.gov (United States)

    Mazzotti, Frank J.; Cherkiss, Michael S.; Parry, Mark; Beauchamp, Jeff; Rochford, Mike; Smith, Brian J.; Hart, Kristen M.; Brandt, Laura A.

    2016-01-01

    Distributional limits of many tropical species in Florida are ultimately determined by tolerance to low temperature. An unprecedented cold spell during 2–11 January 2010, in South Florida provided an opportunity to compare the responses of tropical American crocodiles with warm-temperate American alligators and to compare the responses of nonnative Burmese pythons with native warm-temperate snakes exposed to prolonged cold temperatures. After the January 2010 cold spell, a record number of American crocodiles (n = 151) and Burmese pythons (n = 36) were found dead. In contrast, no American alligators and no native snakes were found dead. American alligators and American crocodiles behaved differently during the cold spell. American alligators stopped basking and retreated to warmer water. American crocodiles apparently continued to bask during extreme cold temperatures resulting in lethal body temperatures. The mortality of Burmese pythons compared to the absence of mortality for native snakes suggests that the current population of Burmese pythons in the Everglades is less tolerant of cold temperatures than native snakes. Burmese pythons introduced from other parts of their native range may be more tolerant of cold temperatures. We documented the direct effects of cold temperatures on crocodiles and pythons; however, evidence of long-term effects of cold temperature on their populations within their established ranges remains lacking. Mortality of crocodiles and pythons outside of their current established range may be more important in setting distributional limits.

  2. [Sports and extreme conditions. Cardiovascular incidence in long term exertion and extreme temperatures (heat, cold)].

    Science.gov (United States)

    Melin, B; Savourey, G

    2001-06-30

    During ultra-endurance exercise, both increase in body temperature and dehydration due to sweat losses, lead to a decrease in central blood volume. The heart rate drift allows maintaining appropriate cardiac output, in order to satisfy both muscle perfusion and heat transfer requirements by increasing skin blood flow. The resulting dehydration can impair thermal regulation and increase the risks of serious accidents as heat stroke. Endurance events, lasting more than 8 hours, result in large sweat sodium chloride losses. Thus, ingestion of large amounts of water with poor salt intake can induce symptomatic hyponatremia (plasma sodium extreme condition.

  3. The effect of extreme cold temperatures on the risk of death in the two major Portuguese cities

    Science.gov (United States)

    Antunes, Liliana; Silva, Susana Pereira; Marques, Jorge; Nunes, Baltazar; Antunes, Sílvia

    2016-06-01

    It is well known that meteorological conditions influence the comfort and human health. Southern European countries, including Portugal, show the highest mortality rates during winter, but the effects of extreme cold temperatures in Portugal have never been estimated. The objective of this study was the estimation of the effect of extreme cold temperatures on the risk of death in Lisbon and Oporto, aiming the production of scientific evidence for the development of a real-time health warning system. Poisson regression models combined with distributed lag non-linear models were applied to assess the exposure-response relation and lag patterns of the association between minimum temperature and all-causes mortality and between minimum temperature and circulatory and respiratory system diseases mortality from 1992 to 2012, stratified by age, for the period from November to March. The analysis was adjusted for over dispersion and population size, for the confounding effect of influenza epidemics and controlled for long-term trend, seasonality and day of the week. Results showed that the effect of cold temperatures in mortality was not immediate, presenting a 1-2-day delay, reaching maximum increased risk of death after 6-7 days and lasting up to 20-28 days. The overall effect was generally higher and more persistent in Lisbon than in Oporto, particularly for circulatory and respiratory mortality and for the elderly. Exposure to cold temperatures is an important public health problem for a relevant part of the Portuguese population, in particular in Lisbon.

  4. The effect of extreme cold temperatures on the risk of death in the two major Portuguese cities

    Science.gov (United States)

    Antunes, Liliana; Silva, Susana Pereira; Marques, Jorge; Nunes, Baltazar; Antunes, Sílvia

    2017-01-01

    It is well known that meteorological conditions influence the comfort and human health. Southern European countries, including Portugal, show the highest mortality rates during winter, but the effects of extreme cold temperatures in Portugal have never been estimated. The objective of this study was the estimation of the effect of extreme cold temperatures on the risk of death in Lisbon and Oporto, aiming the production of scientific evidence for the development of a real-time health warning system. Poisson regression models combined with distributed lag non-linear models were applied to assess the exposure-response relation and lag patterns of the association between minimum temperature and all-causes mortality and between minimum temperature and circulatory and respiratory system diseases mortality from 1992 to 2012, stratified by age, for the period from November to March. The analysis was adjusted for over dispersion and population size, for the confounding effect of influenza epidemics and controlled for long-term trend, seasonality and day of the week. Results showed that the effect of cold temperatures in mortality was not immediate, presenting a 1-2-day delay, reaching maximum increased risk of death after 6-7 days and lasting up to 20-28 days. The overall effect was generally higher and more persistent in Lisbon than in Oporto, particularly for circulatory and respiratory mortality and for the elderly. Exposure to cold temperatures is an important public health problem for a relevant part of the Portuguese population, in particular in Lisbon.

  5. Who is more vulnerable to death from extremely cold temperatures? A case-only approach in Hong Kong with a temperate climate

    Science.gov (United States)

    Qiu, Hong; Tian, Linwei; Ho, Kin-fai; Yu, Ignatius T. S.; Thach, Thuan-Quoc; Wong, Chit-Ming

    2016-05-01

    The short-term effects of ambient cold temperature on mortality have been well documented in the literature worldwide. However, less is known about which subpopulations are more vulnerable to death related to extreme cold. We aimed to examine the personal characteristics and underlying causes of death that modified the association between extreme cold and mortality in a case-only approach. Individual information of 197,680 deaths of natural causes, daily temperature, and air pollution concentrations in cool season (November-April) during 2002-2011 in Hong Kong were collected. Extreme cold was defined as those days with preceding week with a daily maximum temperature at or less than the 1st percentile of its distribution. Logistic regression models were used to estimate the effects of modification, further controlling for age, seasonal pattern, and air pollution. Sensitivity analyses were conducted by using the 5th percentile as cutoff point to define the extreme cold. Subjects with age of 85 and older were more vulnerable to extreme cold, with an odds ratio (OR) of 1.33 (95 % confidence interval (CI), 1.22-1.45). The greater risk of extreme cold-related mortality was observed for total cardiorespiratory diseases and several specific causes including hypertensive diseases, stroke, congestive heart failure, chronic obstructive pulmonary disease (COPD), and pneumonia. Hypertensive diseases exhibited the greatest vulnerability to extreme cold exposure, with an OR of 1.37 (95 % CI, 1.13-1.65). Sensitivity analyses showed the robustness of these effect modifications. This evidence on which subpopulations are vulnerable to the adverse effects of extreme cold is important to inform public health measures to minimize those effects.

  6. 2D DEM analyses for T-M coupling effects of extreme temperatures on surrounding rock-supporting system of a tunnel in cold region

    Institute of Scientific and Technical Information of China (English)

    张玉军; 杨朝帅; 王永刚

    2013-01-01

    Taking the Kunlunshan Tunnel on Qinghai Tibet Railway as an engineering background, the curved wall-inverted arch lining of the tunnel was simplified into the straight wall-umbrella arch one, and the fractured rock mass with developed joints was treated as a discrete medium in the calculation. Using the UDEC code, the numerical simulations for thermo-mechanical coupling processes in the surrounding rock mass-supporting system were carried out aiming at the conditions of mean temperature, extreme highest temperature and extreme lowest temperature in one year. The distributions and changes of stresses, displacements, plastic zones, temperatures in the rock mass of near field, as well as the loading states in the model-building concrete and bolting were investigated and compared for these three computation cases. The results show that compared with the case of mean temperature, the ranges, where the temperatures of surrounding rock mass change obviously, are 6.0 m and 6.5 m, respectively, for the cases of extreme highest temperature and extreme lowest temperature; the displacements of tunnel are raised by 3.2 9.3 and 5.7 12.7 times, and the thicknesses of plastic zones reach 1.5 2.5 m and 2.0 4.5 m for case 2 and 3, respectively; the extreme temperatures of air have strong effects on the stress, deformation and failure states of supporting structure of tunnel in cold region, and the influence degree of extreme lowest temperature is the highest.

  7. Responses of the bed bug, Cimex lectularius, to temperature extremes and dehydration: levels of tolerance, rapid cold hardening and expression of heat shock proteins.

    Science.gov (United States)

    Benoit, J B; Lopez-Martinez, G; Teets, N M; Phillips, S A; Denlinger, D L

    2009-12-01

    This study of the bed bug, Cimex lectularius, examines tolerance of adult females to extremes in temperature and loss of body water. Although the supercooling point (SCP) of the bed bugs was approximately -20 degrees C, all were killed by a direct 1 h exposure to -16 degrees C. Thus, this species cannot tolerate freezing and is killed at temperatures well above its SCP. Neither cold acclimation at 4 degrees C for 2 weeks nor dehydration (15% loss of water content) enhanced cold tolerance. However, bed bugs have the capacity for rapid cold hardening, i.e. a 1-h exposure to 0 degrees C improved their subsequent tolerance of -14 and -16 degrees C. In response to heat stress, fewer than 20% of the bugs survived a 1-h exposure to 46 degrees C, and nearly all were killed at 48 degrees C. Dehydration, heat acclimation at 30 degrees C for 2 weeks and rapid heat hardening at 37 degrees C for 1 h all failed to improve heat tolerance. Expression of the mRNAs encoding two heat shock proteins (Hsps), Hsp70 and Hsp90, was elevated in response to heat stress, cold stress and during dehydration and rehydration. The response of Hsp90 was more pronounced than that of Hsp70 during dehydration and rehydration. Our results define the tolerance limits for bed bugs to these commonly encountered stresses of temperature and low humidity and indicate a role for Hsps in responding to these stresses.

  8. Winter Storms and Extreme Cold

    Science.gov (United States)

    ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ... Landslides & Debris Flow Nuclear Blast Nuclear Power Plants Power Outages Pandemic Radiological Dispersion Device Severe Weather Snowstorms & Extreme ...

  9. Spatiotemporal variability of extreme temperature frequency and amplitude in China

    Science.gov (United States)

    Zhang, Yuanjie; Gao, Zhiqiu; Pan, Zaitao; Li, Dan; Huang, Xinhui

    2017-03-01

    Temperature extremes in China are examined based on daily maximum and minimum temperatures from station observations and multiple global climate models. The magnitude and frequency of extremes are expressed in terms of return values and periods, respectively, estimated by the fitted Generalized Extreme Value (GEV) distribution of annual extreme temperatures. The observations suggest that changes in temperature extremes considerably exceed changes in the respective climatological means during the past five decades, with greater amplitude of increases in cold extremes than in warm extremes. The frequency of warm (cold) extremes increases (decreases) over most areas, with an increasingly faster rate as the extremity level rises. Changes in warm extremes are more dependent on the varying shape of GEV distribution than the location shift, whereas changes in cold extremes are more closely associated with the location shift. The models simulate the overall pattern of temperature extremes during 1961-1981 reasonably well in China, but they show a smaller asymmetry between changes in warm and cold extremes primarily due to their underestimation of increases in cold extremes especially over southern China. Projections from a high emission scenario show the multi-model median change in warm and cold extremes by 2040 relative to 1971 will be 2.6 °C and 2.8 °C, respectively, with the strongest changes in cold extremes shifting southward. By 2040, warm extremes at the 1971 20-year return values would occur about every three years, while the 1971 cold extremes would occur once in > 500 years.

  10. Sports in extreme conditions: the impact of exercise in cold temperatures on asthma and bronchial hyper-responsiveness in athletes.

    Science.gov (United States)

    Carlsen, Kai-Håkon

    2012-09-01

    Exercise-induced asthma (EIA) and bronchial hyper-responsiveness (BHR) are frequently reported among elite athletes of outdoor endurance winter sports, particularly in cross-country and biathlon skiers. The pathogenesis of EIA is related to water loss and heat-loss through the increased respiration during exercise, leading to mediator release, airways inflammation and increased parasympathetic nervous activity in the airways, causing bronchial constriction and BHR. In the competing elite athlete this is presently considered to be due to the frequently repeated increased ventilation during training and competitions in combination with the repeated environmental exposure to cold air in outdoor winter sports. It is important that athletes at risk of asthma and BHR are monitored through regular medical control with assessment of lung function and BHR, and when BHR or asthma is diagnosed, optimal controlling treatment through anti-inflammatory treatment by inhaled steroids should be started and relieving treatment (inhaled ipratropium bromide and inhaled β2-agonists) should be used to relieve bronchial constriction if present.

  11. Extremely Cold Winter Months in Europe (1951-2010

    Directory of Open Access Journals (Sweden)

    Twardosz Robert

    2016-12-01

    Full Text Available Investigation of extreme thermal conditions is important from the perspective of global warming. Therefore, this study has been undertaken in order to determine the frequency, timing and spatial extent of extremely cold months in winter time at 60 weather stations across Europe over a sixty-year period from 1951 to 2010. Extremely cold months (ECMs are defined as months in which the average air temperature is lower than the corresponding multi-annual average by at least 2 standard deviations. Half of all the ECMs occurred in the years 1951-1970 (33 out of 67. The lowest number of ECMs was recorded in the decade 1991-2000, but since the beginning of the 21st century, their density and territorial extent has started to increase again. The extremely cold months with ECMs of the greatest spatial extent, covering at least one third of the stations (over 20 stations, included: February 1954 (22, February 1956 (36, January 1963 (25, and January 1987 (23 stations.

  12. Multiple aspects of northern hemispheric wintertime cold extremes as revealed by Markov chain analysis

    Science.gov (United States)

    Kim, Hye-Sil; Choi, Yong-Sang; Kim, Joo-Hong; Kim, WonMoo

    2017-02-01

    High-impact cold extremes have continued to bring devastating socioeconomic losses in recent years. In order to explain the exposure to cold extremes more comprehensively, this study investigates multiple aspects of boreal winter cold extremes, i.e., frequency, persistence, and entropy (Markovian descriptors). Cold extremes are defined by the bottom 10th percentile of daily minimum temperatures during 1950-2014 over the northern hemisphere. The spatial and temporal distributions of Markovian descriptors during 65 years are examined. Climatological mean fields show the spatial coincidence of higher frequency, shorter persistence, and higher entropy of cold extremes, and vice versa. In regard to the temporal variations over six representative regions of North America, Europe, and Asia, all regions share a decreasing tendency of frequency with the increases in regional winter mean temperature. By contrast, persistence and entropy show their intrinsic decadal variability depending on regions irrespective of the regional temperature variability, which give different information from frequency. Therefore, the exposure to cold extremes would not simply decrease with regional warming. Rather these results indicate that the descriptors with multiple aspects of the extremes would be needed to embrace the topical features as well as the holistic nature of cold extremes.

  13. New analogies between extreme QCD and cold atoms

    Energy Technology Data Exchange (ETDEWEB)

    Nishida, Yusuke [Los Alamos National Laboratory

    2012-08-15

    We discuss two new analogies between extreme QCD and cold atoms. One is the analogue of 'hard probes' in cold atoms. The other is the analogue of 'quark-hadron continuity' in cold atoms.

  14. Trends in mean and extreme temperatures over Ibadan, Southwest Nigeria

    Science.gov (United States)

    Abatan, Abayomi A.; Osayomi, Tolulope; Akande, Samuel O.; Abiodun, Babatunde J.; Gutowski, William J.

    2017-01-01

    In recent times, Ibadan has been experiencing an increase in mean temperature which appears to be linked to anthropogenic global warming. Previous studies have indicated that the warming may be accompanied by changes in extreme events. This study examined trends in mean and extreme temperatures over Ibadan during 1971-2012 at annual and seasonal scales using the high-resolution atmospheric reanalysis from European Centre for Medium-Range Weather Forecasts (ECMWF) twentieth-century dataset (ERA-20C) at 15 grid points. Magnitudes of linear trends in mean and extreme temperatures and their statistical significance were calculated using ordinary least squares and Mann-Kendall rank statistic tests. The results show that Ibadan has witnessed an increase in annual and seasonal mean minimum temperatures. The annual mean maximum temperature exhibited a non-significant decline in most parts of Ibadan. While trends in cold extremes at annual scale show warming, trends in coldest night show greater warming than in coldest day. At the seasonal scale, we found that Ibadan experienced a mix of positive and negative trends in absolute extreme temperature indices. However, cold extremes show the largest trend magnitudes, with trends in coldest night showing the greatest warming. The results compare well with those obtained from a limited number of stations. This study should inform decision-makers and urban planners about the ongoing warming in Ibadan.

  15. NAO influence on extreme winter temperatures in Madrid (Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Prieto, L.; Garcia, R.; Hernandez, E.; Teso, T. del [Dept. Fisica de la Tierra II, Fac. CC. Fisicas, Univ. Complutense de Madrid (Spain); Diaz, J. [Centro Universitario de Salud Publica, Univ. Autonoma de Madrid (Spain)

    2002-12-01

    Extremely cold days (ECDs), with minimum temperatures lower than -4.6 C, have been analysed for Madrid. This threshold corresponds to the 5th percentile of the period 1963-1999. Adopting a case analysis approach, five synoptic patterns have been identified that produce these extremely low temperatures. Three of them are associated with cold air flows over the Iberian Peninsula, and the other two with a lack of significant circulation over the region. A non-linear association with the North Atlantic oscillation (NAO) has been identified using log-linear models. The NAO positive phase leads to an increase in the winter frequency of those synoptic patterns associated with stagnant air flow over Iberia, while those characterised by cold, northern flows do not appear to be similarly influenced. (orig.)

  16. Frequent extreme cold exposure and brown fat and cold-induced thermogenesis: a study in a monozygotic twin.

    Directory of Open Access Journals (Sweden)

    Maarten J Vosselman

    Full Text Available INTRODUCTION: Mild cold acclimation is known to increase brown adipose tissue (BAT activity and cold-induced thermogenesis (CIT in humans. We here tested the effect of a lifestyle with frequent exposure to extreme cold on BAT and CIT in a Dutch man known as 'the Iceman', who has multiple world records in withstanding extreme cold challenges. Furthermore, his monozygotic twin brother who has a 'normal' sedentary lifestyle without extreme cold exposures was measured. METHODS: The Iceman (subject A and his brother (subject B were studied during mild cold (13°C and thermoneutral conditions (31°C. Measurements included BAT activity and respiratory muscle activity by [18F]FDG-PET/CT imaging and energy expenditure through indirect calorimetry. In addition, body temperatures, cardiovascular parameters, skin perfusion, and thermal sensation and comfort were measured. Finally, we determined polymorphisms for uncoupling protein-1 and β3-adrenergic receptor. RESULTS: Subjects had comparable BAT activity (A: 1144 SUVtotal and B: 1325 SUVtotal, within the range previously observed in young adult men. They were genotyped with the polymorphism for uncoupling protein-1 (G/G. CIT was relatively high (A: 40.1% and B: 41.9%, but unlike during our previous cold exposure tests in young adult men, here both subjects practiced a g-Tummo like breathing technique, which involves vigorous respiratory muscle activity. This was confirmed by high [18F]FDG-uptake in respiratory muscle. CONCLUSION: No significant differences were found between the two subjects, indicating that a lifestyle with frequent exposures to extreme cold does not seem to affect BAT activity and CIT. In both subjects, BAT was not higher compared to earlier observations, whereas CIT was very high, suggesting that g-Tummo like breathing during cold exposure may cause additional heat production by vigorous isometric respiratory muscle contraction. The results must be interpreted with caution given the

  17. The Definition and Classification of Extensive and Persistent Extreme Cold Events in China

    Institute of Scientific and Technical Information of China (English)

    PENG Jing-Bei; BUEH Cholaw

    2011-01-01

    Using the observed daily temperatures from 756 stations in China during the period from 1951 to 2009, extensive and persistent extreme cold events (EPECEs) were defined according to the following three steps: 1) a station was defined as an extreme cold station (ECS) if the observed temperature was lower than its 10th percentile threshold; 2) an extensive extreme cold event was determined to be present if the approximated area occupied by the ECSs was more than 10% of the total area of China (83rd percentile) on its starting day and the maximum area occupied by the ECSs was at least 20% of the total area of China (96th percentile); and 3) an EPECE was determined to be present if the extensive extreme cold event lasted for at least for eight days. 52 EPECEs were identified in this manner, and these identification results were also verified using other reliable data. On the basis of cluster analysis, five types of EPECEs were classified according to the spatial distribution of ECSs at their most extensive time over the course of the EPECE.

  18. Mechanisms underlying temperature extremes in Iberia: a Lagrangian perspective

    Directory of Open Access Journals (Sweden)

    João A. Santos

    2015-04-01

    Full Text Available The mechanisms underlying the occurrence of temperature extremes in Iberia are analysed considering a Lagrangian perspective of the atmospheric flow, using 6-hourly ERA-Interim reanalysis data for the years 1979–2012. Daily 2-m minimum temperatures below the 1st percentile and 2-m maximum temperatures above the 99th percentile at each grid point over Iberia are selected separately for winter and summer. Four categories of extremes are analysed using 10-d backward trajectories initialized at the extreme temperature grid points close to the surface: winter cold (WCE and warm extremes (WWE, and summer cold (SCE and warm extremes (SWE. Air masses leading to temperature extremes are first transported from the North Atlantic towards Europe for all categories. While there is a clear relation to large-scale circulation patterns in winter, the Iberian thermal low is important in summer. Along the trajectories, air mass characteristics are significantly modified through adiabatic warming (air parcel descent, upper-air radiative cooling and near-surface warming (surface heat fluxes and radiation. High residence times over continental areas, such as over northern-central Europe for WCE and, to a lesser extent, over Iberia for SWE, significantly enhance these air mass modifications. Near-surface diabatic warming is particularly striking for SWE. WCE and SWE are responsible for the most extreme conditions in a given year. For WWE and SCE, strong temperature advection associated with important meridional air mass transports are the main driving mechanisms, accompanied by comparatively minor changes in the air mass properties. These results permit a better understanding of mechanisms leading to temperature extremes in Iberia.

  19. New algorithm for extreme temperature measurements

    NARCIS (Netherlands)

    Damean, N.

    2000-01-01

    A new algorithm for measurement of extreme temperature is presented. This algorithm reduces the measurement of the unknown temperature to the solving of an optimal control problem, using a numerical computer. Based on this method, a new device for extreme temperature measurements is projected. It co

  20. Risk of hospitalization for fire-related burns during extreme cold weather.

    Science.gov (United States)

    Ayoub, Aimina; Kosatsky, Tom; Smargiassi, Audrey; Bilodeau-Bertrand, Marianne; Auger, Nathalie

    2017-10-01

    Environmental factors are important predictors of fires, but no study has examined the association between outdoor temperature and fire-related burn injuries. We sought to investigate the relationship between extremely cold outdoor temperatures and the risk of hospitalization for fire-related burns. We carried out a time-stratified case-crossover study of 2470 patients hospitalized for fire-related burn injuries during cold months between 1989 and 2014 in Quebec, Canada. The main exposure was the minimum outdoor temperature on the day of and the day before the burn. We computed odds ratios (OR) and 95% confidence intervals (CI) to evaluate the relationship between minimum temperature and fire-related burns, and assessed how associations varied across sex and age. Exposure to extreme cold temperature was associated with a significantly higher risk of hospitalization for fire-related burns. Compared with 0°C, exposure to a minimum temperature of -30°C was associated with an OR of 1.51 (95% CI 1.22-1.87) for hospitalization for fire-related burns. The associations were somewhat stronger for women, youth, and the elderly. Compared with 0°C, a minimum temperature of -30°C was associated with an OR for fire-related burn hospitalization of 1.65 for women (95% CI 1.13-2.40), 1.60 for age fire-related burns. Measures to prevent fires should be implemented prior to the winter season, and enhanced during extreme cold. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Temperature limit values for gripping cold surfaces

    NARCIS (Netherlands)

    Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.

    2002-01-01

    Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four

  2. Temperature limit values for gripping cold surfaces

    NARCIS (Netherlands)

    Malchaire, J.; Geng, Q.; Den Hartog, E.; Havenith, G.; Holmer, I.; Piette, A.; Powell, S.L.; Rintamäki, H.; Rissanen, S.

    2002-01-01

    Objectives. At the request of the European Commission and in the framework of the European Machinery Directive, research was conducted jointly in five different laboratories to develop specifications for surface temperature limit values for the gripping and handling of cold items. Methods. Four hund

  3. Trend of monthly temperature and daily extreme temperature during 1951-2012 in New Zealand

    Science.gov (United States)

    Caloiero, Tommaso

    2017-07-01

    Among several variables affecting climate change and climate variability, temperature plays a crucial role in the process because its variations in monthly and extreme values can impact on the global hydrologic cycle and energy balance through thermal forcing. In this study, an analysis of temperature data has been performed over 22 series observed in New Zealand. In particular, to detect possible trends in the time series, the Mann-Kendall non-parametric test was first applied at monthly scale and then to several indices of extreme daily temperatures computed since 1951. The results showed a positive trend in both the maximum and the minimum temperatures, in particular, in the autumn-winter period. This increase has been evaluated faster in maximum temperature than in minimum one. The trend analysis of the temperature indices suggests that there has been an increase in the frequency and intensity of hot extremes, while most of the cold extremes showed a downward tendency.

  4. Quantum Thermal Transport through Extremely Cold Dielectric Chains

    Institute of Scientific and Technical Information of China (English)

    LIU Hui-Ping; YI Lin

    2006-01-01

    In the framework of Green's function theory out of equilibrium, a Landauer-Buttiker (LB) formula for thermal conductance is derived. A simplified model for describing extremely cold dielectric chains is proposed for the first time. Fhrther we apply the present LB formula for studying thermal conductance at low-lying modes, emerging in dielectric atom chains. We find that quantum thermal conductance undergoes an anomalous transition due to new quasiparticle excitations, resulting from nonlinear atom-atom interactions. This theoretical prediction is in excellent agreement with a high-accuracy measurement to thermal conductance quantum.

  5. Projected Changes in Temperature Extremes in China Using PRECIS

    Directory of Open Access Journals (Sweden)

    Yujing Zhang

    2017-01-01

    Full Text Available Temperature extremes can cause disastrous impacts on ecological and social economic systems. China is very sensitive to climate change, as its warming rate exceeds that of the global mean level. This paper focused on the spatial and temporal changes of the temperature extremes characterized by the 95th percentile of maximum temperature (TX95, the 5th percentile of the minimum temperature (TN5, high-temperature days (HTD and low-temperature days (LTD. The daily maximum and minimum temperatures generated by PRECIS under different Representative Concentration Pathways (RCPs are used in the research. The results show that: (1 Model simulation data can reproduce the spatial distribution features of the maximum temperature (Tmax and minimum temperature (Tmin as well as that of the extreme temperature indices; (2 By the end of the 21st century (2070–2099, both the Tmax and Tmin are warmer than the baseline level (1961–1990 in China and the eight sub-regions. However, there are regional differences in the asymmetrical warming features, as the Tmin warms more than the Tmax in the northern part of China and the Tibetan Plateau, while the Tmax warms more than the Tmin in the southern part of China; (3 The frequency of the warm extremes would become more usual, as the HTD characterized by the present-day threshold would increase by 106%, 196% and 346%, under RCP2.6, RCP4.5 and RCP8.5, respectively, while the cold extremes characterized by the LTD would become less frequent by the end of the 21st century, decreasing by 75%, 90% and 98% under RCP2.6, RCP4.5 and RCP8.5, respectively. The southern and eastern parts of the Tibetan Plateau respond sensitively to changes in both the hot and cold extremes, suggesting its higher likelihood to suffer from climate warming; (4 The intensity of the warm (cold extremes would increase (decrease significantly, characterized by the changes in the TX95 (TN5 by the end of the 21st century, and the magnitude of the

  6. Extreme Temperatures May Increase Risk for Low Birth Weight at Term

    Science.gov (United States)

    ... at term, NIH study suggests Skip sharing on social media links Share this: Page Content Monday, February 27, 201 7 -Stock photo Extreme hot or cold temperatures during pregnancy may increase the risk that infants born at ...

  7. Trends in rainfall and temperature extremes in Morocco

    Directory of Open Access Journals (Sweden)

    K. Khomsi

    2015-02-01

    Full Text Available In Morocco, socioeconomic fields are vulnerable to weather extreme events. This work aims to analyze the frequency and the trends of temperature and rainfall extreme events in two contrasted Moroccan regions (the Tensift in the semi-arid South, and the Bouregreg in the sub-humid North, during the second half of the 20th century. This study considers long time series of daily extreme temperatures and rainfall, recorded in the stations of Marrakech and Safi for the Tensift region, and Kasba-Tadla and Rabat-Sale for the Bouregreg region, data from four other stations (Tanger, Fes, Agadir and Ouarzazate from outside the regions were added. Extremes are defined by using as thresholds the 1st, 5th, 90th, 95th, and 99th percentiles. Results show upward trends in maximum and minimum temperatures of both regions and no generalized trends in rainfall amounts. Changes in cold events are larger than those for warm events, and the number of very cold events decrease significantly in the whole studied area. The southern region is the most affected with the changes of the temperature regime. Most of the trends found in rainfall heavy events are positive with weak magnitudes even though no statistically significant generalized trends could be identified during both seasons.

  8. Betavoltaic performance under extreme temperatures

    Directory of Open Access Journals (Sweden)

    Adams Tom

    2016-01-01

    Full Text Available Longevity of sensors and portable devices is severely limited by temperature, chemical instability, and electrolyte leakage issues associated with conventional electrochemical batteries. Betavoltaics, which operate similar to photo voltaics, can operate in a wide temperature range safely without permanent degradation. Though not a new concept, which began in the 1950's and peaked in the mid 1970's, research has been minimal and sporadic until recent advancements in ultra-low power electronics and materialization of low power applications. The technology is rapidly maturing, generating research, and development in increasing the beta emitting source and semiconductor efficiencies. This study presents an update on betavoltaic technology, results from temperature evaluation on commercially available General Licensed betavoltaic cells, development of a hybrid system for latent and burst power, modeling and simulation techniques and results, and current and proposed research and development. Betavoltaic performance was successfully demonstrated for a wide temperature range (-30°C to 70°C. Short circuit current and open circuit voltage were used to compare electrical performance. Results indicate that the open-circuit voltage and maximum power decreased as temperature increased due to increases in the semiconductor's intrinsic carrier concentration.

  9. Extreme Environment High Temperature Communication Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The purpose of this project is to develop and demonstrate a communications system capable of operation at extreme temperatures and pressures in hostile and corrosive...

  10. Flexible diaphragm-extreme temperature usage

    Science.gov (United States)

    Lerma, Guillermo (Inventor)

    1991-01-01

    A diaphragm suitable for extreme temperature usage, such as encountered in critical aerospace applications, is fabricated by a unique method, and of a unique combination of materials. The materials include multilayered lay-ups of diaphragm materials sandwiched between layers of bleeder fabrics. After being formed in the desired shape on a mold, they are vacuum sealed and then cured under pressure, in a heated autoclave. A bond capable of withstanding extreme temperatures are produced.

  11. Characterizing the Effects of Extreme Cold Using Real-time Syndromic Surveillance, Ontario, Canada, 2010-2016.

    Science.gov (United States)

    VanStone, Nancy; van Dijk, Adam; Chisamore, Timothy; Mosley, Brian; Hall, Geoffrey; Belanger, Paul; Michael Moore, Kieran

    Morbidity and mortality from exposure to extreme cold highlight the need for meaningful temperature thresholds to activate public health alerts. We analyzed emergency department (ED) records for cold temperature-related visits collected by the Acute Care Enhanced Surveillance system-a syndromic surveillance system that captures data on ED visits from hospitals in Ontario-for geographic trends related to ambient winter temperature. We used 3 Early Aberration Reporting System algorithms of increasing sensitivity-C1, C2, and C3-to determine the temperature at which anomalous counts of cold temperature-related ED visits occurred in northern and southern Ontario from 2010 to 2016. The C2 algorithm was the most sensitive detection method. Results showed lower threshold temperatures for Acute Care Enhanced Surveillance alerts in northern Ontario than in southern Ontario. Public health alerts for cold temperature warnings that are based on cold temperature-related ED visit counts and ambient temperature may improve the accuracy of public warnings about cold temperature risks.

  12. Changes of temperature and precipitation extremes in China: past and future

    Science.gov (United States)

    Wen, Xin; Fang, Guohua; Qi, Heshuai; Zhou, Lei; Gao, Yuqin

    2016-10-01

    Historical temperature and precipitation extremes and their potential future changes are quantified and evaluated throughout the landmass of China. A statistical model of climate extremes based on generalized extreme value (GEV) distribution is applied to both historical climate data and bias correction and spatial disaggregation (BCSD) downscaled Coupled Model Inter-comparison Project phase 5 (CMIP5) projections. The results indicate relatively moderate historical warm extreme conditions in China with regional means of maximum temperature 28.9, 29.4, and 29.8 °C for 10-, 20-, and 50-year return periods, respectively, whereas the corresponding regional means of minimum temperature are -20.1, -20.8, and -21.5 °C, manifesting a downward trend northwardly with relative larger regional variations in cold extremes. The historical precipitation extremes also decline gradually from south-southeast toward northwest with significant regional differences. As for the future, the warm extremes are expected to aggravate by roughly 1.66-4.92 °C projected by CMIP5, indicating larger increasing rate and spatial differences compared to cold extremes. The extreme precipitation is projected to increase 7.9-13.4 %, the dry regions would see a larger increasing rate compared to wet regions. The increasing radiative forcing concentration would trigger upward variations in both temperature and precipitation extreme magnitudes. Also, the warm extreme changes are more sensitive to the radiative forcing concentration than the cold extremes. The CMIP5 projections basically maintain a favorable inter-model consistency in temperature and rainfall extreme simulation for the future, but the inter-model difference of warm extremes is larger than cold extremes.

  13. Mangrove species' responses to winter air temperature extremes in China

    Science.gov (United States)

    Chen, Luzhen; Wang, Wenqing; Li, Qingshun Q.; Zhang, Yihui; Yang, Shengchang; Osland, Michael J.; Huang, Jinliang; Peng, Congjiao

    2017-01-01

    The global distribution and diversity of mangrove forests is greatly influenced by the frequency and intensity of winter air temperature extremes. However, our understanding of how different mangrove species respond to winter temperature extremes has been lacking because extreme freezing and chilling events are, by definition, relatively uncommon and also difficult to replicate experimentally. In this study, we investigated species-specific variation in mangrove responses to winter temperature extremes in China. In 10 sites that span a latitudinal gradient, we quantified species-specific damage and recovery following a chilling event, for mangrove species within and outside of their natural range (i.e., native and non-native species, respectively). To characterize plant stress, we measured tree defoliation and chlorophyll fluorescence approximately one month following the chilling event. To quantify recovery, we measured chlorophyll fluorescence approximately nine months after the chilling event. Our results show high variation in the geographic- and species-specific responses of mangroves to winter temperature extremes. While many species were sensitive to the chilling temperatures (e.g., Bruguiera sexangula and species in the Sonneratia and Rhizophora genera), the temperatures during this event were not cold enough to affect certain species (e.g., Kandelia obovata, Aegiceras corniculatum, Avicennia marina, and Bruguiera gymnorrhiza). As expected, non-native species were less tolerant of winter temperature extremes than native species. Interestingly, tidal inundation modulated the effects of chilling. In comparison with other temperature-controlled mangrove range limits across the world, the mangrove range limit in China is unique due to the combination of the following three factors: (1) Mangrove species diversity is comparatively high; (2) winter air temperature extremes, rather than means, are particularly intense and play an important ecological

  14. The non-Gaussianity and spatial asymmetry of temperature extremes relative to the jet: the role of horizontal advection

    Science.gov (United States)

    Harnik, Nili; Garfinkel, Chaim

    2016-04-01

    Global warming is expected raise the number of warm spells and lower the number of cold spells, by simply shifting of the near-surface temperature probability distribution to warmer temperatures. However, changes in the shape of distribution strongly affect how the occurrence of temperature extremes will change. Hence, understanding the processes shaping the spatial and statistical distribution of temperature variations and extremes in the present climate is central to understanding how temperature extremes might vary in the future. Using meteorological reanalyses data we show that the distribution of near-surface temperature variability is non-Gaussian, and consistent with this, extreme warm anomalies occur preferentially poleward of the location of extreme cold anomalies. The non-Guassianity evident in reanalysis data is also found in a set of dry General Circulation Model runs in which the jet is forced at different latitudes, and the location of extremes is influenced by the location of the jet stream. Using a simple model of Lagrangian temperature advection, we investigate the role of synoptic dynamics in causing this non Gaussianity. The meridional shifting between cold and warm extremes, and the related non-Gaussianity are traced back to the synoptic evolution leading up to cold and warm extreme events. We find that the meridional movement of synotpic systems, as well as nonlinear temperature advection are both of crucial importance for the warm/cold asymmetry in the latitudinal distribution of the temperature extremes. The possible implications for future changes in extremes will be briefly discussed.

  15. Mechanism of sand slide - cold lahar induced by extreme rainfall

    Science.gov (United States)

    Fukuoka, Hiroshi; Yamada, Masumi; Dok, Atitkagna

    2014-05-01

    Along with the increasing frequencies of extreme rainfall events in almost every where on the earth, shallow slide - debris flow, i.e. cold lahars running long distance often occurs and claims downslope residents lives. In the midnight of 15 October 2013, Typhoon Wilpha attacked the Izu-Oshima, a active volcanic Island and the extreme rainfall of more than 800 mm / 24 hours was recorded. This downpour of more than 80 mm/hr lasted 4 hours at its peak and caused a number of cold lahars. The initial stage of those lahars was shallow slides of surface black volcanic ash deposits, containing mostly fine sands. The thickness was only 50 cm - 1 m. In the reconnaissance investigation, author found that the sliding surface was the boundary of two separate volcanic ash layers between the black and yellow colored and apparently showing contrast of permeability and hardness. Permeability contrast may have contributed to generation of excess pore pressure on the border and trigger the slide. Then, the unconsolidated, unpacked mass was easily fluidized and transformed into mud flows, that which volcanologists call cold lahars. Seismometers installed for monitoring the active volcano's activities, succeeded to detect many tremors events. Many are spikes but 5 larger and longer events were extracted. They lasted 2 -3 minutes and if we assume that this tremors reflects the runout movement, then we can calculate the mean velocity of the lahars. Estimated velocity was 45 - 60 km/h, which is much higher than the average speed 30 - 40 km/h of debris flows observed in Japan. Flume tests of volcanic ash flows by the Forestry and Forest Products Research Institute showed the wet volcanic ash can run at higher speed than other materials. The two tremor records were compare d with the local residents witnessed and confirmed by newspaper reported that the reach of the lahar was observed at the exact time when tremor ends. We took the black volcanic ash and conducted ring shear tests to

  16. Recent trends of extreme temperature indices for the Iberian Peninsula

    Science.gov (United States)

    Fonseca, D.; Carvalho, M. J.; Marta-Almeida, M.; Melo-Gonçalves, P.; Rocha, A.

    2016-08-01

    Climate change and extreme climate events have a significant impact on societies and ecosystems. As a result, climate change projections, especially related with extreme temperature events, have gained increasing importance due to their impacts on the well-being of the population and ecosystems. However, most studies in the field are based on coarse global climate models (GCMs). In this study, we perform a high resolution downscaling simulation to evaluate recent trends of extreme temperature indices. The model used was Weather Research and Forecast (WRF) forced by MPI-ESM-LR, which has been shown to be one of the more robust models to simulate European climate. The domain used in the simulations includes the Iberian Peninsula and the simulation covers the 1986-2005 period (i.e. recent past). In order to study extreme temperature events, trends were computed using the Theil-Sen method for a set of temperature indexes defined by the Expert Team on Climate Change Detection and Indices (ETCCDI). For this, daily values of minimum and maximum temperatures were used. The trends of the indexes were computed for annual and seasonal values and the Mann-Kendall Trend test was used to evaluate their statistical significance. In order to validate the results, a second simulation, in which WRF was forced by ERA-Interim, was performed. The results suggest an increase in the number of warm days and warm nights, especially during summer and negative trends for cold nights and cold days for the summer and spring. For the winter, contrary to the expected, the results suggest an increase in cold days and cold nights (warming hiatus). This behavior is supported by the WRF simulation forced by ERA-Interim for the autumn days, pointing to an extension of the warming hiatus phenomenon to the remaining seasons. These results should be used with caution since the period used to calculate the trends may not be long enough for this purpose. However, the general sign of trends are similar for

  17. Future changes in extreme temperature events using the statistical downscaling model (SDSM in the trans-boundary region of the Jhelum river basin

    Directory of Open Access Journals (Sweden)

    Rashid Mahmood

    2014-10-01

    On the whole in the Jhelum basin, the intensity and frequency of warm temperature extremes are likely to be higher and the intensity and frequency of cold temperature extremes to be lower in the future.

  18. Can reanalysis datasets describe the persistent temperature and precipitation extremes over China?

    Science.gov (United States)

    Zhu, Jian; Huang, Dan-Qing; Yan, Pei-Wen; Huang, Ying; Kuang, Xue-Yuan

    2016-08-01

    The persistent temperature and precipitation extremes may bring damage to the economy and human due to their intensity, duration and areal coverage. Understanding the quality of reanalysis datasets in descripting these extreme events is important for detection, attribution and model evaluation. In this study, the performances of two reanalysis datasets [the twentieth century reanalysis (20CR) and Interim ECMWF reanalysis (ERA-Interim)] in reproducing the persistent temperature and precipitation extremes in China are evaluated. For the persistent temperature extremes, the two datasets can better capture the intensity indices than the frequency indices. The increasing/decreasing trend of persistent warm/cold extremes has been reasonably detected by the two datasets, particularly in the northern part of China. The ERA-Interim better reproduces the climatology and tendency of persistent warm extremes, while the 20CR has better skill to depict the persistent cold extremes. For the persistent precipitation extremes, the two datasets have the ability to reproduce the maximum consecutive 5-day precipitation. The two datasets largely underestimate the maximum consecutive dry days over the northern part of China, while overestimate the maximum consecutive wet days over the southern part of China. For the response of the precipitation extremes against the temperature variations, the ERA-Interim has good ability to depict the relationship among persistent precipitation extremes, local persistent temperature extremes, and global temperature variations over specific regions.

  19. How predictable is the winter extremely cold days over temperate East Asia?

    Science.gov (United States)

    Luo, Xiao; Wang, Bin

    2016-07-01

    Skillful seasonal prediction of the number of extremely cold day (NECD) has considerable benefits for climate risk management and economic planning. Yet, predictability of NECD associated with East Asia winter monsoon remains largely unexplored. The present work estimates the NECD predictability in temperate East Asia (TEA, 30°-50°N, 110°-140°E) where the current dynamical models exhibit limited prediction skill. We show that about 50 % of the total variance of the NECD in TEA region is likely predictable, which is estimated by using a physics-based empirical (P-E) model with three consequential autumn predictors, i.e., developing El Niño/La Niña, Eurasian Arctic Ocean temperature anomalies, and geopotential height anomalies over northern and eastern Asia. We find that the barotropic geopotential height anomaly over Asia can persist from autumn to winter, thereby serving as a predictor for winter NECD. Further analysis reveals that the sources of the NECD predictability and the physical basis for prediction of NECD are essentially the same as those for prediction of winter mean temperature over the same region. This finding implies that forecasting seasonal mean temperature can provide useful information for prediction of extreme cold events. Interpretation of the lead-lag linkages between the three predictors and the predictand is provided for stimulating further studies.

  20. The association of extreme temperatures and the incidence of tuberculosis in Japan

    Science.gov (United States)

    Onozuka, Daisuke; Hagihara, Akihito

    2015-08-01

    Seasonal variation in the incidence of tuberculosis (TB) has been widely assumed. However, few studies have investigated the association between extreme temperatures and the incidence of TB. We collected data on cases of TB and mean temperature in Fukuoka, Japan for 2008-2012 and used time-series analyses to assess the possible relationship of extreme temperatures with TB incident cases, adjusting for seasonal and interannual variation. Our analysis revealed that the occurrence of extreme heat temperature events resulted in a significant increase in the number of TB cases (relative risk (RR) 1.20, 95 % confidence interval (CI) 1.01-1.43). We also found that the occurrence of extreme cold temperature events resulted in a significant increase in the number of TB cases (RR 1.23, 95 % CI 1.05-1.45). Sex and age did not modify the effect of either heat or cold extremes. Our study provides quantitative evidence that the number of TB cases increased significantly with extreme heat and cold temperatures. The results may help public health officials predict extreme temperature-related TB incidence and prepare for the implementation of preventive public health interventions.

  1. Relativistic QED Plasma at Extremely High Temperature

    CERN Document Server

    Masood, Samina S

    2016-01-01

    Renormalization scheme of QED (Quantum Electrodynamics) at high temperatures is used to calculate the effective parameters of relativistic plasma in the early universe. Renormalization constants of QED play role of effective parameters of the theory and can be used to determine the collective behavior of the medium. We explicitly show that the dielectric constant, magnetic reluctivity, Debye length and the plasma frequency depend on temperature in the early universe. Propagation speed, refractive index, plasma frequency and Debye shielding length of a QED plasma are computed at extremely high temperatures in the early universe. We also found the favorable conditions for the relativistic plasma from this calculations.

  2. Extreme low temperature tolerance in woody plants

    Directory of Open Access Journals (Sweden)

    George Richard Strimbeck

    2015-10-01

    Full Text Available Woody plants in boreal to arctic environments and high mountains survive prolonged exposure to temperatures below -40˚C and minimum temperatures below -60˚C, and laboratory tests show that many of these species can also survive immersion in liquid nitrogen at -196˚C. Studies of biochemical changes that occur during acclimation, including recent proteomic and metabolomic studies, have identified changes in carbohydrate and compatible solute concentrations, membrane lipid composition, and proteins, notably dehydrins, that may have important roles in survival at extreme low temperature. Consideration of the biophysical mechanisms of membrane stress and strain lead to the following hypotheses for cellular and molecular mechanisms of survival at extreme low temperature: 1. Changes in lipid composition stabilize membranes at temperatures above the lipid phase transition temperature (-20 to 30˚C, preventing phase changes that result in irreversible injury. 2. High concentrations of oligosaccharides promote vitrification or high viscosity in the cytoplasm in freeze-dehydrated cells, which would prevent deleterious interactions between membranes. 3. Dehydrins bind membranes and further promote vitrification or act stearically to prevent membrane-membrane interactions.

  3. Investigation of Loop Heat Pipe Survival and Restart After Extreme Cold Environment Exposure

    Science.gov (United States)

    Golliher, Eric; Ku, Jentung; Licari, Anthony; Sanzi, James

    2010-01-01

    NASA plans human exploration near the South Pole of the Moon, and other locations where the environment is extremely cold. This paper reports on the heat transfer performance of a loop heat pipe (LHP) exposed to extreme cold under the simulated reduced gravitational environment of the Moon. A common method of spacecraft thermal control is to use a LHP with ammonia working fluid. Typically, a small amount of heat is provided either by electrical heaters or by environmental design, such that the LHP condenser temperature never drops below the freezing point of ammonia. The concern is that a liquid-filled, frozen condenser would not restart, or that a thawing condenser would damage the tubing due to the expansion of ammonia upon thawing. This paper reports the results of an experimental investigation of a novel approach to avoid these problems. The LHP compensation chamber (CC) is conditioned such that all the ammonia liquid is removed from the condenser and the LHP is nonoperating. The condenser temperature is then reduced to below that of the ammonia freezing point. The LHP is then successfully restarted.

  4. Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

    Science.gov (United States)

    Mienis, F.; Duineveld, G. C. A.; Davies, A. J.; Lavaleye, M. M. S.; Ross, S. W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M. J. N.; de Haas, H.; Brooke, S.; van Weering, T. C. E.

    2014-05-01

    day, which is the largest temperature variability as measured so far in a cold-water coral habitat. Warm events, related to Gulf Stream meanders, had the duration of roughly 1 week and the current during these events was directed to the NNE. The consequences of such events must be significant given the strong effects of temperature on the metabolism of cold-water corals. Furthermore, elevated acoustic backscatter values and high mass fluxes were also recorded during these events, indicating a second stressor that may affect the corals. The abrasive nature of sand in combination with strong currents might sand blast the corals. We conclude that cold-water corals near Cape Lookout live under extreme conditions that limit mound growth at present.

  5. Forecasting extreme temperature health hazards in Europe

    Science.gov (United States)

    Di Napoli, Claudia; Pappenberger, Florian; Cloke, Hannah L.

    2017-04-01

    Extreme hot temperatures, such as those experienced during a heat wave, represent a dangerous meteorological hazard to human health. Heat disorders such as sunstroke are harmful to people of all ages and responsible for excess mortality in the affected areas. In 2003 more than 50,000 people died in western and southern Europe because of a severe and sustained episode of summer heat [1]. Furthermore, according to the Intergovernmental Panel on Climate Change heat waves are expected to get more frequent in the future thus posing an increasing threat to human lives. Developing appropriate tools for extreme hot temperatures prediction is therefore mandatory to increase public preparedness and mitigate heat-induced impacts. A recent study has shown that forecasts of the Universal Thermal Climate Index (UTCI) provide a valid overview of extreme temperature health hazards on a global scale [2]. UTCI is a parameter related to the temperature of the human body and its regulatory responses to the surrounding atmospheric environment. UTCI is calculated using an advanced thermo-physiological model that includes the human heat budget, physiology and clothing. To forecast UTCI the model uses meteorological inputs, such as 2m air temperature, 2m water vapour pressure and wind velocity at body height derived from 10m wind speed, from NWP models. Here we examine the potential of UTCI as an extreme hot temperature prediction tool for the European area. UTCI forecasts calculated using above-mentioned parameters from ECMWF models are presented. The skill in predicting UTCI for medium lead times is also analysed and discussed for implementation to international health-hazard warning systems. This research is supported by the ANYWHERE project (EnhANcing emergencY management and response to extreme WeatHER and climate Events) which is funded by the European Commission's HORIZON2020 programme. [1] Koppe C. et al., Heat waves: risks and responses. World Health Organization. Health and

  6. Data Converters Performance at Extreme Temperatures

    Science.gov (United States)

    Rejeshuni, Rarnesham; Kumar, Nikil; Mao, James; Keymeulen, Didier; Zebulum, Ricardo S.; Stoica, Adrian

    2006-01-01

    Space missions often require radiation and extreme-temperature hardened electronics to survive the harsh environments beyond earth's atmosphere. Traditional approaches to preserve electronics incorporate shielding, insulation and redundancy at the expense of power and weight. However, a novel way of bypassing these problems is the concept of evolutionary hardware. A reconfgurable device, consisting of several switches interconnected with analog/digital parts, is controlled by an evolutionary processor (EP). When the EP detects degradation in the circuit it sends signals to reconfgure the switches, thus forming a new circuit with the desired output. This concept has been developed since the mid-90s, but one problem remains - the EP cannot degrade substantially. For this reason, extensive testing at extreme temperatures (-180' to 120(deg)C) has been done on devices found on FPGA boards (taking the role of the EP) such as the Analog to Digital and the Digital to Analog Converter. Analysis of the results has shown that FPGA boards implementing EP with some compensation may be a practical solution to evolving circuits. This paper describes results on the tests of data converters at extreme temperatures.

  7. Estimating changes in temperature extremes from millennial-scale climate simulations using generalized extreme value (GEV) distributions

    Science.gov (United States)

    Huang, Whitney K.; Stein, Michael L.; McInerney, David J.; Sun, Shanshan; Moyer, Elisabeth J.

    2016-07-01

    Changes in extreme weather may produce some of the largest societal impacts of anthropogenic climate change. However, it is intrinsically difficult to estimate changes in extreme events from the short observational record. In this work we use millennial runs from the Community Climate System Model version 3 (CCSM3) in equilibrated pre-industrial and possible future (700 and 1400 ppm CO2) conditions to examine both how extremes change in this model and how well these changes can be estimated as a function of run length. We estimate changes to distributions of future temperature extremes (annual minima and annual maxima) in the contiguous United States by fitting generalized extreme value (GEV) distributions. Using 1000-year pre-industrial and future time series, we show that warm extremes largely change in accordance with mean shifts in the distribution of summertime temperatures. Cold extremes warm more than mean shifts in the distribution of wintertime temperatures, but changes in GEV location parameters are generally well explained by the combination of mean shifts and reduced wintertime temperature variability. For cold extremes at inland locations, return levels at long recurrence intervals show additional effects related to changes in the spread and shape of GEV distributions. We then examine uncertainties that result from using shorter model runs. In theory, the GEV distribution can allow prediction of infrequent events using time series shorter than the recurrence interval of those events. To investigate how well this approach works in practice, we estimate 20-, 50-, and 100-year extreme events using segments of varying lengths. We find that even using GEV distributions, time series of comparable or shorter length than the return period of interest can lead to very poor estimates. These results suggest caution when attempting to use short observational time series or model runs to infer infrequent extremes.

  8. Extreme temperatures in summer time. Health implications

    Directory of Open Access Journals (Sweden)

    Julio Díaz Jiménez

    2005-12-01

    Full Text Available The increment that has been detected in summer temperatures in the last years joined to the trends expected to climate for the next century provide an increase in frequency and intensity of the extreme climate events, basically in heat waves. The undoubted relationship between temperature and mortality makes necessary a quantifying in order to characterize the expected effects of temperature over mortality particularly in heat waves.This study show a state-of-the-art review this problem, with a special emphasis in the heat wave that Europe suffered in summer of 2003 and how the heat waves has been characterized until now. Lastly, which are the characteristics that should have the preventive measures designed to minimized the effects of heat waves over population ́s health.

  9. Constructing and screening a metagenomic library of a cold and alkaline extreme environment

    DEFF Research Database (Denmark)

    Glaring, Mikkel Andreas; Vester, Jan Kjølhede; Stougaard, Peter

    2017-01-01

    Natural cold or alkaline environments are common on Earth. A rare combination of these two extremes is found in the permanently cold (less than 6 °C) and alkaline (pH above 10) ikaite columns in the Ikka Fjord in Southern Greenland. Bioprospecting efforts have established the ikaite columns...

  10. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, Derek R.; Schweiger, Michael J.; Riley, Brian J.; Pokorny, Richard; Hrma, Pavel R.

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of molten glass. Knowing the temperature profile within a cold cap will help determine its characteristics and relate them to the rate of glass production. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Since a direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed where the textural features in a laboratory-made cold cap with a high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. To correlate the temperature distribution to microstructures within the cold cap, microstructures were identified of individual feed samples that were heat treated to set temperatures between 400°C and 1200°C and quenched. The temperature distribution within the cold cap was then established by correlating cold-cap regions with the feed samples of nearly identical structures and was compared with the temperature profile from a mathematical model.

  11. Trends in daily temperature and precipitation extremes over Georgia, 1971–2010

    Directory of Open Access Journals (Sweden)

    I. Keggenhoff

    2014-08-01

    Full Text Available Annual changes to climate extreme indices in Georgia (Southern Caucasus from 1971 to 2010 are studied using homogenized daily minimum and maximum temperature and precipitation series. Fourteen extreme temperature and 11 extreme precipitation indices are selected from the list of core climate extreme indices recommended by the World Meteorological Organization – Commission for Climatology (WMO-CCL and the research project on Climate Variability and Predictability (CLIVAR of the World Climate Research Programme (WCRP. Trends in the extreme indices are studied for 10 minimum and 11 maximum temperature and 24 precipitation series for the period 1971–2010. Between 1971 and 2010 most of the temperature extremes show significant warming trends. In 2010 there are 13.3 fewer frost days than in 1971. Within the same time frame there are 13.6 more summer days and 7.0 more tropical nights. A large number of stations show significant warming trends for monthly minimum and maximum temperature as well as for cold and warm days and nights throughout the study area, whereas warm extremes and night-time based temperature indices show greater trends than cold extremes and daytime indices. Additionally, the warm spell duration indicator indicates a significant increase in the frequency of warm spells between 1971 and 2010. Cold spells show an insignificant increase with low spatial coherence. Maximum 1-day and 5-day precipitation, the number of very heavy precipitation days, very wet and extremely wet days as well as the simple daily intensity index all show an increase in Georgia, although all trends manifest a low spatial coherence. The contribution of very heavy and extremely heavy precipitation to total precipitation increased between 1971 and 2010, whereas the number of wet days decreases.

  12. Associating emergency room visits with first and prolonged extreme temperature event in Taiwan: A population-based cohort study.

    Science.gov (United States)

    Wang, Yu-Chun; Lin, Yu-Kai; Chuang, Chun-Yu; Li, Ming-Hsu; Chou, Chang-Hung; Liao, Chun-Hui; Sung, Fung-Chang

    2012-02-01

    The present study evaluated emergency room visit (ERV) risks for all causes and cardiopulmonary diseases associated with temperature and long-lasting extreme temperatures from 2000 to 2009 in four major cities in Taiwan. The city-specific daily average temperatures at the high 95th, 97th, and 99th percentiles, and the low 10th, 5th, and 1st percentiles were defined as extreme heat and cold. A distributed lag non-linear model was used to estimate the cumulative relative risk (RR) of ERV for morbidities associated with temperatures (0 to 3-day lags), extreme heat and cold lasting for 2 to 9 days or longer, and with the annual first extreme heat or cold event after controlling for covariates. Low temperatures were associated with slightly higher ERV risks than high temperatures for circulatory diseases. After accounting for 4-day cumulative temperature effect, the ERV risks for all causes and respiratory diseases were found to be associated with extreme cold at the 5th percentile lasting for >8 days and 1st percentile lasting for >3 days. The annual first extreme cold event of 5th percentile or lower temperatures was also significantly associated with ERV, with RRs ranging from 1.09 to 1.12 for all causes and from 1.15 to 1.26 for respiratory diseases. The annual first extreme heat event of 99th percentile temperature was associated with higher ERV for all causes and circulatory diseases. Annual first extreme temperature event and intensified prolonged extreme cold events are associated with increased ERVs in Taiwan.

  13. Advanced Flip Chips in Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni

    2010-01-01

    The use of underfill materials is necessary with flip-chip interconnect technology to redistribute stresses due to mismatching coefficients of thermal expansion (CTEs) between dissimilar materials in the overall assembly. Underfills are formulated using organic polymers and possibly inorganic filler materials. There are a few ways to apply the underfills with flip-chip technology. Traditional capillary-flow underfill materials now possess high flow speed and reduced time to cure, but they still require additional processing steps beyond the typical surface-mount technology (SMT) assembly process. Studies were conducted using underfills in a temperature range of -190 to 85 C, which resulted in an increase of reliability by one to two orders of magnitude. Thermal shock of the flip-chip test articles was designed to induce failures at the interconnect sites (-40 to 100 C). The study on the reliability of flip chips using underfills in the extreme temperature region is of significant value for space applications. This technology is considered as an enabling technology for future space missions. Flip-chip interconnect technology is an advanced electrical interconnection approach where the silicon die or chip is electrically connected, face down, to the substrate by reflowing solder bumps on area-array metallized terminals on the die to matching footprints of solder-wettable pads on the chosen substrate. This advanced flip-chip interconnect technology will significantly improve the performance of high-speed systems, productivity enhancement over manual wire bonding, self-alignment during die joining, low lead inductances, and reduced need for attachment of precious metals. The use of commercially developed no-flow fluxing underfills provides a means of reducing the processing steps employed in the traditional capillary flow methods to enhance SMT compatibility. Reliability of flip chips may be significantly increased by matching/tailoring the CTEs of the substrate

  14. Trends in Temperature Extremes in Association with Weather-Intraseasonal Fluctuations in Eastern China

    Institute of Scientific and Technical Information of China (English)

    QIAN Cheng; YAN Zhongwei; Zhaohua WU; FU Congbin; TU Kai

    2011-01-01

    Trends in the frequencies of four temperature extremes (the occurrence of warm days, cold days, warm nights and cold nights) with respect to a modulated annual cycle (MAC), and those associated exclusively with weather-intraseasonal fluctuations (WIF) in eastern China were investigated based on an updated homogenized daily maximum and minimum temperature dataset for 1960-2008. The Ensemble Empirical Mode Decomposition (EEMD) method was used to isolate the WIF, MAC, and longer-term components from the temperature series. The annual, winter and summer occurrences of warm (cold) nights were found to have increased (decreased) significantly almost everywhere, while those of warm (cold) days have increased (decreased) in northern China (north of 40°N). However, the four temperature extremes associated exclusively with WIF for winter have decreased almost everywhere, while those for summer have decreased in the north but increased in the south. These characteristics agree with changes in the amplitude of WIF. In particular, winter WIF of maximum temperature tended to weaken almost everywhere, especially in eastern coastal areas (by 10%-20%); summer WIF tended to intensify in southern China by 10%-20%. It is notable that in northern China, the occurrence of warm days has increased, even where that associated with WIF has decreased significantly. This suggests that the recent increasing frequency of warm extremes is due to a considerable rise in the mean temperature level, which surpasses the effect of the weakening weather fluctuations in northern China.

  15. Impacts of temperature extremes on cardiovascular morbidity and mortality in the Czech Republic

    Science.gov (United States)

    Davídkovová, H.; Kyselý, J.; Plavcová, E.; Urban, A.; Kriz, B.; Kyncl, J.

    2012-04-01

    Elevated mortality associated with high ambient temperatures in summer represents one of the main impacts of weather extremes on human society. Increases in cardiovascular mortality during heat waves have been reported in many European countries; much less is known about which particular cardiovascular disorders are most affected during heat waves, and whether similar patterns are found for morbidity (hospital admissions). Relatively less understood is also cold-related mortality and morbidity in winter, when the relationships between weather and human health are more complex, less direct, and confounded by other factors such as epidemics of influenza/acute respiratory infections. The present study analyses relationships between temperature extremes and cardiovascular morbidity and mortality. We make use of the datasets on hospital admissions and daily mortality in the population of the Czech Republic (about 10.3 million) over 1994-2009. The data have been standardized to remove the effects of the long-term trend and the seasonal and weekly cycles. Periods when the morbidity/mortality data were affected by epidemics of influenza and other acute respiratory infections have been removed from the analysis. We use analogous definitions for hot and cold spells based on quantiles of daily average temperature anomalies, which allows for a comparison of the findings for summer hot spells and winter cold spells. The main aims of the study are (i) to identify deviations of mortality and morbidity from the baseline associated with hot and cold spells, (ii) to compare the hot- and cold-spell effects for individual cardiovascular diseases (e.g. ischaemic heart disease I20-I25, cerebrovascular disease I60-I69, hypertension I10, aterosclerosis I70) and to identify those diagnoses that are most closely linked to temperature extremes, (iii) to identify population groups most vulnerable to temperature extremes, and (iv) to compare the links to temperature extremes for morbidity and

  16. Temperature Distribution within a Cold Cap during Nuclear Waste Vitrification.

    Science.gov (United States)

    Dixon, Derek R; Schweiger, Michael J; Riley, Brian J; Pokorny, Richard; Hrma, Pavel

    2015-07-21

    The kinetics of the feed-to-glass conversion affects the waste vitrification rate in an electric glass melter. The primary area of interest in this conversion process is the cold cap, a layer of reacting feed on top of the molten glass. The work presented here provides an experimental determination of the temperature distribution within the cold cap. Because direct measurement of the temperature field within the cold cap is impracticable, an indirect method was developed in which the textural features in a laboratory-made cold cap with a simulated high-level waste feed were mapped as a function of position using optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and X-ray diffraction. The temperature distribution within the cold cap was established by correlating microstructures of cold-cap regions with heat-treated feed samples of nearly identical structures at known temperatures. This temperature profile was compared with a mathematically simulated profile generated by a cold-cap model that has been developed to assess the rate of glass production in a melter.

  17. The effect of myostatin genotype on body temperature during extreme temperature events.

    Science.gov (United States)

    Howard, J T; Kachman, S D; Nielsen, M K; Mader, T L; Spangler, M L

    2013-07-01

    Extreme heat and cold events can create deleterious physiological changes in cattle as they attempt to cope. The genetic background of animals can influence their response to these events. The objective of the current study was to determine the impact of myostatin genotype (MG) on body temperature during periods of heat and cold stress. Two groups of crossbred steers and heifers of unknown pedigree and breed fraction with varying percentages of Angus, Simmental, and Piedmontese were placed in a feedlot over 2 summers and 2 winters. Before arrival, animals were genotyped for the Piedmontese-derived myostatin mutation (C313Y) to determine their MG as either homozygous normal (0 copy; n = 84), heterozygous (1 copy; n = 96), or homozygous for inactive myostatin (2 copy; n = 59). Hourly tympanic and vaginal temperature measurements were collected for steers and heifers, respectively, for 5 d during times of anticipated heat and cold stress. Mean (±SD) ambient temperature for summer and winter stress events were 24.4 (±4.64) and -1.80 (±11.71), respectively. A trigonometric function (sine + cosine) with periods of 12 and 24 h was used to describe the diurnal cyclical pattern. Hourly body temperature was analyzed within a season, and fixed effects included MG, group, trigonometric functions nested within group, and interaction of MG with trigonometric functions nested within group; random effects were animal and residual (Model [I]). A combined analysis of season and group was also investigated with the inclusion of season as a main effect and the nesting of effects within both group and season (Model [C]). In both models, the residual was fitted using an autoregressive covariance structure. A 3-way interaction of MG, season, and trigonometric function periodicities of 24 h (P 0.05). The current study illustrated that a genotype × environment interaction exists for MG and 1-copy animals were more robust to environmental extremes in comparison with 0- or 2-copy animals.

  18. Finite Temperature Field Theory of "Extreme Black Holes"

    OpenAIRE

    Degura, Yoshitaka; Shiraishi, Kiyoshi

    2000-01-01

    We treat the model which describes "extreme black holes" moving slowly. We derive an effective lagrangian in the low energy for this model and then investigate a statistical behavior of "extreme black holes" in the finite temperature.

  19. Coaxial Cables for Martian Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Harvey, Wayne L.; Valas, Sam; Tsai, Michael C.

    2011-01-01

    Work was conducted to validate the use of the rover external flexible coaxial cabling for space under the extreme environments to be encountered during the Mars Science Laboratory (MSL) mission. The antennas must survive all ground operations plus the nominal 670-Martian-day mission that includes summer and winter seasons of the Mars environment. Successful development of processes established coaxial cable hardware fatigue limits, which were well beyond the expected in-flight exposures. In keeping with traditional qualification philosophy, this was accomplished by subjecting flight-representative coaxial cables to temperature cycling of the same depth as expected in-flight, but for three times the expected number of in-flight thermal cycles. Insertion loss and return loss tests were performed on the coaxial cables during the thermal chamber breaks. A vector network analyzer was calibrated and operated over the operational frequency range 7.145 to 8.450 GHz. Even though some of the exposed cables function only at UHF frequencies (approximately 400 MHz), the testing was more sensitive, and extending the test range down to 400 MHz would have cost frequency resolution. The Gore flexible coaxial cables, which were the subject of these tests, proved to be robust and displayed no sign of degradation due to the 3X exposure to the punishing Mars surface operations cycles.

  20. The role of land use change in the recent warming of daily extreme temperatures

    Science.gov (United States)

    Christidis, Nikolaos; Stott, Peter A.; Hegerl, Gabriele C.; Betts, Richard A.

    2013-02-01

    Abstract Understanding how temperature extremes respond in a climate forced by human activity is of great importance, as extreme temperatures are detrimental to health and often responsible for mortality increases. While previous detection and attribution studies demonstrated a significant human influence on the recent warming of daily extremes, contributions of individual anthropogenic forcings like changes in land use have not yet been investigated in such studies. Here we apply an optimal fingerprinting technique to data from observations and experiments with a new earth system model to examine whether changing land use has led to detectable changes in daily extreme temperatures on a quasi-global scale. We find that loss of trees and increase of grassland since preindustrial times has caused an overall cooling trend in both mean and extreme temperatures which is detectable in the observed changes of warm but not cold extremes. The warming in both mean and extreme temperatures due to anthropogenic forcings other than land use is detected in all cases, whereas the weaker effect of natural climatic forcings is not detected in any. This is the first formal attribution of observed climatic changes to changing land use, suggesting further investigations are justified, particularly in studies of warm extremes.

  1. What caused the recent ``Warm Arctic, Cold Continents'' trend pattern in winter temperatures?

    Science.gov (United States)

    Sun, Lantao; Perlwitz, Judith; Hoerling, Martin

    2016-05-01

    The emergence of rapid Arctic warming in recent decades has coincided with unusually cold winters over Northern Hemisphere continents. It has been speculated that this "Warm Arctic, Cold Continents" trend pattern is due to sea ice loss. Here we use multiple models to examine whether such a pattern is indeed forced by sea ice loss specifically and by anthropogenic forcing in general. While we show much of Arctic amplification in surface warming to result from sea ice loss, we find that neither sea ice loss nor anthropogenic forcing overall yield trends toward colder continental temperatures. An alternate explanation of the cooling is that it represents a strong articulation of internal atmospheric variability, evidence for which is derived from model data, and physical considerations. Sea ice loss impact on weather variability over the high-latitude continents is found, however, to be characterized by reduced daily temperature variability and fewer cold extremes.

  2. Recent trends in pre-monsoon daily temperature extremes over India

    Indian Academy of Sciences (India)

    D R Kothawale; J V Revadekar; K Rupa Kumar

    2010-02-01

    Extreme climate and weather events are increasingly being recognized as key aspects of climate change. Pre-monsoon season (March–May) is the hottest part of the year over almost the entire South Asian region, in which hot weather extremes including heat waves are recurring natural hazards having serious societal impacts, particularly on human health. In the present paper, recent trends in extreme temperature events for the pre-monsoon season have been studied using daily data on maximum and minimum temperatures over a well-distributed network of 121 stations for the period 1970–2005. For this purpose, time series of extreme temperature events have been constructed for India as a whole and seven homogeneous regions, viz., Western Himalaya (WH), Northwest (NW), Northeast (NE), North Central (NC), East coast (EC), West coast (WC) and Interior Peninsula (IP). In general, the frequency of occurrence of hot days and hot nights showed widespread increasing trend, while that of cold days and cold nights has shown widespread decreasing trend. The frequency of the occurrence of hot days is found to have significantly increased over EC, WC and IP, while that of cold days showed significant decreasing trend over WH and WC. The three regions EC, WC and NW showed significant increasing trend in the frequency of hot nights. For India as whole, the frequency of hot days and nights showed increasing trend while cold days and nights showed decreasing trends. Day-to-day fluctuations of pre-monsoon daily maximum and minimum temperatures have also been studied for the above regions. The results show that there is no significant change in day-to-day magnitude of fluctuations of pre-monsoon maximum and minimum temperatures. However, the results generally indicate that the daily maximum and minimum temperatures are becoming less variable within the season.

  3. Assessment of climate variations in temperature and precipitation extreme events over Iran

    Science.gov (United States)

    Soltani, M.; Laux, P.; Kunstmann, H.; Stan, K.; Sohrabi, M. M.; Molanejad, M.; Sabziparvar, A. A.; Ranjbar SaadatAbadi, A.; Ranjbar, F.; Rousta, I.; Zawar-Reza, P.; Khoshakhlagh, F.; Soltanzadeh, I.; Babu, C. A.; Azizi, G. H.; Martin, M. V.

    2016-11-01

    In this study, changes in the spatial and temporal patterns of climate extreme indices were analyzed. Daily maximum and minimum air temperature, precipitation, and their association with climate change were used as the basis for tracking changes at 50 meteorological stations in Iran over the period 1975-2010. Sixteen indices of extreme temperature and 11 indices of extreme precipitation, which have been quality controlled and tested for homogeneity and missing data, are examined. Temperature extremes show a warming trend, with a large proportion of stations having statistically significant trends for all temperature indices. Over the last 15 years (1995-2010), the annual frequency of warm days and nights has increased by 12 and 14 days/decade, respectively. The number of cold days and nights has decreased by 4 and 3 days/decade, respectively. The annual mean maximum and minimum temperatures averaged across Iran both increased by 0.031 and 0.059 °C/decade. The probability of cold nights has gradually decreased from more than 20 % in 1975-1986 to less than 15 % in 1999-2010, whereas the mean frequency of warm days has increased abruptly between the first 12-year period (1975-1986) and the recent 12-year period (1999-2010) from 18 to 40 %, respectively. There are no systematic regional trends over the study period in total precipitation or in the frequency and duration of extreme precipitation events. Statistically significant trends in extreme precipitation events are observed at less than 15 % of all weather stations, with no spatially coherent pattern of change, whereas statistically significant changes in extreme temperature events have occurred at more than 85 % of all weather stations, forming strongly coherent spatial patterns.

  4. Representing Extreme Temperature Events and Resolving Their Implications for Yield

    Science.gov (United States)

    Huybers, P. J.; Mueller, N. D.; Butler, E. E.; Tingley, M.; McKinnon, K. A.; Rhines, A. N.

    2014-12-01

    Although it is well recognized that extreme temperatures occurring at particular growth stages are destructive to yield, there appears substantial scope for improved empirical assessment and simulation of the relationship between temperature and yield. Several anecdotes are discussed. First, a statistical analysis of historical U.S. extreme temperatures is provided. It is demonstrated that both reanalysis and model simulations significantly differ from near-surface temperature observations in the frequency and magnitude of extremes. This finding supports empirical assessment using near-surface instrumental records and underscores present difficulties in simulating past and predicting future changes. Second, an analysis of the implications of extreme temperatures on U.S. maize yield is provided where the response is resolved regionally and according to growth stage. Sensitivity to extreme temperatures during silking is found to be uniformly high across the U.S., but the response during grain filling varies spatially, with higher sensitivity in the North. This regional and growth-stage dependent sensitivity implies the importance of representing cultivar, planting times, and development rates, and is also indicative of the potential for future changes according to the combined effects of climate and technology. Finally, interaction between extreme temperatures and agriculture is indicated by analysis showing that historical extreme temperatures in the U.S. Midwest have cooled in relation to changes in regional productivity, possibly because of greater potential for cooling through evapotranspiration. This interpretation is consistent with changes in crop physiology and management, though also noteworthy is that the moderating influence of increased evapotranspiration on extreme temperatures appears to be lost during severe drought. Together, these findings indicate that a more accurate assessment of the historical relationship between extreme temperatures and yield

  5. Damage Characteristics of Altered and Unaltered Diabases Subjected to Extremely Cold Freeze-Thaw Cycles

    Science.gov (United States)

    Luo, Xuedong; Jiang, Nan; Zuo, Changqun; Dai, Zhenwei; Yan, Suntao

    2014-11-01

    Altered and unaltered diabases are commonly deposited on hydrothermally mineralized slopes. To study their damage characteristics during freeze-thaw cycles, they were sampled from Cihai iron ore mine located in an extremely cold region, Xinjiang, China and examined using acoustic and X-ray diffraction experiments to analyze the differences in their main mineral components and explore their damage characteristics under freeze-thaw conditions. Based on the results of these experiments, their damage and degradation patterns were obtained and the evolution of their physical characteristics including the rock mass loss rate ( L F), rock strength loss rate ( R σ ), P-wave velocity loss rate ( V l), and freeze-thaw coefficient ( K f) was analyzed. In addition, two groups of equations were established to characterize the relationships of these physical and mechanical properties of the rock specimens with the number and temperature of freeze-thaw cycles. The results show that the mineral composition of diabase changes during its alteration, showing increased clay and calcite, and the degradation and evolution patterns of the physical and mechanical parameters ( L F, R σ , V l, and K f) of the altered rocks during freeze-thaw cycles are different from those of diabase, with the altered diabase exhibiting greater damage than the diabase.

  6. Moving in extreme environments: open water swimming in cold and warm water.

    Science.gov (United States)

    Tipton, Michael; Bradford, Carl

    2014-01-01

    Open water swimming (OWS), either 'wild' such as river swimming or competitive, is a fast growing pastime as well as a part of events such as triathlons. Little evidence is available on which to base high and low water temperature limits. Also, due to factors such as acclimatisation, which disassociates thermal sensation and comfort from thermal state, individuals cannot be left to monitor their own physical condition during swims. Deaths have occurred during OWS; these have been due to not only thermal responses but also cardiac problems. This paper, which is part of a series on 'Moving in Extreme Environments', briefly reviews current understanding in pertinent topics associated with OWS. Guidelines are presented for the organisation of open water events to minimise risk, and it is concluded that more information on the responses to immersion in cold and warm water, the causes of the individual variation in these responses and the precursors to the cardiac events that appear to be the primary cause of death in OWS events will help make this enjoyable sport even safer.

  7. Circulation anomalies associated with winter temperature extremes in Athens during the period 1900-2004

    Energy Technology Data Exchange (ETDEWEB)

    Founda, D. [National Observatory of Athens (Greece). Inst. for Environmental Research and Sustainable Development; Loon, H. van [Colorado Univ., Boulder, CO (United States)

    2008-02-15

    We use the long series of temperature observed at the National Observatory of Athens, Greece, to examine the extremes of this element together with associated anomalies in the general circulation of the atmosphere. The 13 extreme-cold and 20 extreme-warm winters during the period 1900-2004 (equal to or below minus one standard deviation, and equal to or above plus one standard deviation respectively) had opposite pressure anomalies, mainly over the North Atlantic and Eurasia. The temperature extremes at Athens were representative of most of the Mediterranean and the Balkans, and their associated pressure anomalies were robust. The extremes of the Index of the North Atlantic Oscillation (the pressure difference between Gibraltar and Iceland) were not a good indicator of the temperature extremes in the Mediterranean. Rather the extreme temperature anomalies over the Mediterranean region are to a large extent controlled by a bipolar pattern of SLP (see level pressure) anomalies with centers over the British Isles and the Arctic. (orig.)

  8. Low temperature tolerance and cold hardening of cacti

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S.

    1982-12-01

    Reduced uptake by the chlorenchyma cells of cacti of a stain (neutral red) was used as an indicator of low-temperature damage resulting from cooling stems in the laboratory. Necrosis set in a few degrees below the temperature at which the fraction of cells accumulating stain was reduced by 50%. Coryphantha vivipara, Opuntia polyacantha, and Pediocactus simpsonii, which range to over 3000 m altitude in southern Wyoming, were quite cold tolerant (50% inhibition of staining occurred from -17/sup 0/ to -20/sup 0/C), while O. bigelovii and O. ramosissima, which are restricted to much warmer habitats, were not very cold tolerant (50% inhibition from -4/sup 0/ to -7/sup 0/). Relationships among tissue cold sensitivity, morphological features which protect the stems from low temperatures, and the occurrence of species in progressively colder regions were investigated. Differences in tissue cold sensitivity accounted for the =600 m higher elevational limit of Coryphantha vivipara var. rosea compared to the morphologically similar var. deserti in southern Nevada. In contrast, morphological differences alone could adequately explain the relative northern limits of the columnar cacti Carnegiea gigantea vs. Stenocereus gummosus and the barrel cacti Ferocactus acanthodes vs. F. wislizenii in the southwestern United States, as previously indicated using a computer model. Differences in both morphology and tissue cold sensitivity apparently influenced the relative northern ranges of Lophocereus schottii with respect to the other columnar cacti and F. covillei with respect to the other barrel cacti, as well as the relative elevational range of Denmoza rhodacantha with respect to Trichocereus candicans in northcentral Argentina. Cold hardening in response to decreasing day/night air temperatures was observed for 10 species.

  9. Low-temperature tolerance and cold hardening of cacti

    Energy Technology Data Exchange (ETDEWEB)

    Nobel, P.S.

    1982-12-01

    Reduced uptake by the chlorenchyma cells of cacti of a stain (neutral red) was used as an indicator of low-temperature damage resulting from cooling stems in the laboratory. Necrosis set in a few degrees below the temperature at which the fraction of cells accumulating stain was reduced by 50%. Coryphantha vivipara, Opuntia polyacantha, and Pediocactus simpsonii, which range to over 300 m altitude in southern Wyoming, were quite cold tolerant. Relationships among tissue cold sensitivity, morphological features which protect the stems from low temperatures, and the occurrence of species in progressively colder regions were investigated. Differences in tissue cold sensitivity accounted for the approx. = 600 m higher elevational limit of Coryphantha vivipara var. rosea compared to the morphologically similar var. deserti in southern Nevada. In contrast, morphological differences alone could adequately explain the relative northern limits of the columnar cacti Carnegiea gigantea vs Stenocereus gummosus and the barrel cacti Ferocactus acanthodes vs. F. wislizenii in the southwestern United States, as previously indicated using a computer model. Cold hardening in response to decreasing day/night air temperatures was observed for 10 species. A decrease from 50/sup 0//40/sup 0/ to 10/sup 0//0/sup 0/ lowered by 4/sup 0/ the temperature at which the fraction of the chlorenchyma cells taking up stain was reduced 50% for both D. rhodacantha and T. candicans, with a half-time for the shift of approx. = 3 d. The tolerance of subzero temperatures and the ability to cold harden allow cacti to range into regions with considerable wintertime freezing.

  10. Temperature limit values for touching cold surfaces with the fingertip

    NARCIS (Netherlands)

    Geng, Q.; Holme, I.; Hartog, E.A. den; Havenith, G.; Jay, O.; Malchaires, J.; Piette, A.; Rintama, H.; Rissanen, S.

    2006-01-01

    Objectives: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold

  11. Temperature limit values for touching cold surfaces with the fingertip

    NARCIS (Netherlands)

    Geng, Q.; Holme, I.; Hartog, E.A. den; Havenith, G.; Jay, O.; Malchaires, J.; Piette, A.; Rintama, H.; Rissanen, S.

    2006-01-01

    Objectives: At the request of the European Commission and in the framework of the European Machinery Directive, research was performed in five different laboratories to develop specifications for surface temperature limit values for the short-term accidental touching of the fingertip with cold surfa

  12. Low temperature annealing of cold-drawn pearlitic steel wire

    DEFF Research Database (Denmark)

    Zhang, Xiaodan; Bech, Jakob Ilsted; Hansen, Niels

    2015-01-01

    Cold-drawn pearlitic steel wires are nanostructured and the flow stress at room temperature can reach values above 6 GPa. A typical characteristic of the nanostructured metals, is the low ductility and thermal stability. In order to optimize both the processing and application of the wires...

  13. Long-Term Trends in Extreme Temperatures in Hong Kong and Southern China

    Institute of Scientific and Technical Information of China (English)

    T. C. LEE; H. S. CHAN; E. W. L. GINN; M. C. WONG

    2011-01-01

    The observed long-term trends in extreme temperatures in Hong Kong were studied based on the meteorological data recorded at the Hong Kong Observatory Headquarters from 1885-2008. Results show that, over the past 124 years, the extreme daily minimum and maximum temperatures, as well as the length of the warm spell in Hong Kong, exhibit statistically significant long-term rising trends, while the length of the cold spell shows a statistically significant decreasing trend. The time-dependent return period analysis also indicated that the return period for daily minimum temperature at 4℃ or lower lengthened considerably from 6 years in 1900 to over 150 years in 2000, while the return periods for daily maximum temperature reaching 35℃ or above shortened drastically from 32 years in 1900 to 4.5 years in 2000. Past trends in extreme temperatures from selected weather stations in southern China from 1951-2004 were also assessed. Over 70% of the stations studied yielded a statistically significant rising trend in extreme daily minimum temperature, while the trend for extreme maximum temperatures was found to vary, with no significant trend established for the majority of stations.

  14. Using Annual Data to Estimate the Public Health Impact of Extreme Temperatures.

    Science.gov (United States)

    Goggins, William B; Yang, Chunyuh; Hokama, Tomiko; Law, Lewis S K; Chan, Emily Y Y

    2015-07-01

    Short-term associations between both hot and cold ambient temperatures and higher mortality have been found worldwide. Few studies have examined these associations on longer time scales. Age-standardized mortality rates (ASMRs) were calculated for 1976-2012 for Hong Kong SAR, People's Republic of China, defining "annual" time periods in 2 ways: from May through April of the following year and from November through October. Annual frequency and severity of extreme temperatures were summarized by using a degree-days approach with extreme heat expressed as annual degree-days >29.3°C and cold as annual degree-days ASMR, with adjustment for long-term trends. Increases of 10 hot or 200 cold degree-days in an annual period, the approximate interquartile ranges for these variables, were significantly (all P's ≤ 0.011) associated with 1.9% or 3.1% increases, respectively, in the annual ASMR for the May-April analyses and with 2.2% or 2.8% increases, respectively, in the November-October analyses. Associations were stronger for noncancer and elderly mortality. Mortality increases associated with extreme temperature are not simply due to short-term forward displacement of deaths that would have occurred anyway within a few weeks.

  15. A Preliminary Study of Surface Temperature Cold Bias in COAMPS

    Energy Technology Data Exchange (ETDEWEB)

    Chin, H-N S; Leach, M J; Sugiyama, G A; Aluzzi, F J

    2001-04-27

    It is well recognized that the model predictability is more or less hampered by the imperfect representations of atmospheric state and model physics. Therefore, it is a common problem for any numerical models to exhibit some sorts of biases in the prediction. In this study, the emphasis is focused on the cold bias of surface temperature forecast in Naval Research Laboratory's three-dimensional mesoscale model, COAMPS (Coupled Ocean/Atmosphere Mesoscale Prediction System). Based on the comparison with the ground station data, there were two types of ground temperature cold biases identified in LLNL (Lawrence Livermore National Laboratory) operational forecasts of COAMPS over the California and Nevada regions during the 1999 winter and the 2000 spring. The first type of cold bias appears at high elevation regions covered by snow, and its magnitude can be as large as 30 F - 40 F lower than observed. The second type of cold bias mainly exists in the snow-free clear-sky regions, where the surface temperature is above the freezing point, and its magnitude can be up to 5 F - 10 F lower than observed. These cold biases can affect the low-level stratification, and even the diurnal variation of winds in the mountain regions, and therefore impact the atmospheric dispersion forecast. The main objective of this study is to explore the causes of such cold bias, and to further the improvement of the forecast performance in COAMPS. A series of experiments are performed to gauge the sensitivity of the model forecast due to the physics changes and large-scale data with various horizontal and vertical resolutions.

  16. Extreme Technicolor & The Walking Critical Temperature

    DEFF Research Database (Denmark)

    Sannino, Francesco; Järvinen, Matti

    2011-01-01

    We map the phase diagram of gauge theories of fundamental interactions in the flavor- temperature plane using chiral perturbation theory to estimate the relation between the pion decaying constant and the critical temperature above which chiral symmetry is restored. We then investigate the impact...

  17. Extreme Technicolor & The Walking Critical Temperature

    DEFF Research Database (Denmark)

    Sannino, Francesco; Järvinen, Matti

    2011-01-01

    We map the phase diagram of gauge theories of fundamental interactions in the flavor- temperature plane using chiral perturbation theory to estimate the relation between the pion decaying constant and the critical temperature above which chiral symmetry is restored. We then investigate the impact...

  18. Attribution analyses of temperature extremes using a set of 16 indices

    Directory of Open Access Journals (Sweden)

    Nikolaos Christidis

    2016-12-01

    Full Text Available Detection and attribution studies have demonstrated that anthropogenic forcings have been driving significant changes in temperature extremes since the middle of the 20th century. Moreover, new methodologies have been developed for the attribution of extreme events that assess how human influence may have changed their characteristics. Here we combine formal statistical analyses based on optimal fingerprinting to attribute observed long term changes in temperature extremes with an ensemble-based approach for event attribution. Our analyses are applied to 16 indices constructed with daily temperature data that focus on different characteristics of extremes and together build up a more complete representation of historical changes in warm and cold extremes than previous studies. For each index we compute an annual value for all years of the post-1960 period using data from observations and experiments with a coupled Earth System model for the analysis of multi-decadal changes and a high-resolution atmospheric model for event attribution. The models indicate that anthropogenic forcings have influenced almost all indices in recent decades and led to more prominent changes in the frequency of extremes. The optimal fingerprinting analyses show that for most indices the anthropogenic signal is detectable in changes during 1961–2010 both in Europe and on a quasi-global scale. The weaker natural effect, resulting mainly from volcanic eruptions, is in most cases not detectable, with the exception of large scale changes in indices linked to the frequency of cold night-time extremes. Our event analyses estimate how anthropogenic forcings alter the chances of getting new record index values in Europe and find that such extremes would be markedly rare if human influence were not accounted for, whereas in the current climate their return times range from a few years to a few decades.

  19. From symmetric cold fission fragment mass distributions to extremely asymmetric alpha decay

    Science.gov (United States)

    Poenaru, D. N.; Ivascu, M.; Maruhn*, J. A.; Greiner*, W.

    1987-12-01

    The analytical superasymmetric fission model, successful in the study of extremely asymmetric decay modes like α-decay and heavy ion radioactivities, is applied to cold fission phenomena. The three groups of processes are described in a unifield manner, showing that cold fission could be considered heavy cluster emission. For 234U all groups have been detected. The highest symmetry of the gragment mass distributions should be observed for the neutron rich nucleus 264Fm, leading to doubly magic products 132Sn. The most probable light fragments from cold fission of 234,236U, 239Np and 240Pu are 100Zr, 104,106,108Mo respectively, in good agreement with experimental data.

  20. From symmetric cold fission fragment mass distributions to extremely asymmetric alpha decay

    Energy Technology Data Exchange (ETDEWEB)

    Poenaru, D.N.; Ivascu, M.; Maruhn, J.A.; Greiner, W.

    1987-12-10

    The analytical superasymmetric fission model, successful in the study of extremely asymmetric decay modes like ..cap alpha..-decay and heavy ion radioactivities, is applied to cold fission phenomena. The three groups of processes are described in a unifield manner, showing that cold fission could be considered heavy cluster emission. For /sup 234/U all groups have been detected. The highest symmetry of the gragment mass distributions should be observed for the neutron rich nucleus /sup 264/Fm, leading to doubly magic products /sup 132/Sn. The most probable light fragments from cold fission of /sup 234,236/U, /sup 239/Np and /sup 240/Pu are /sup 100/Zr, /sup 104,106,108/Mo respectively, in good agreement with experimental data.

  1. Observations of the cold mid-latitude mesopause using airglow-derived temperatures and SABER data

    Science.gov (United States)

    Gelinas, L. J.; Hecht, J. H.; Walterscheid, R. L.; Mlynczak, M. G.; Reid, I. M.

    2016-12-01

    Aerospace imagers deployed at Alice Springs (23o42'S, 133o53'E) and Adelaide (34o55'S, 138o36'E) have been operating nearly continuously since 2001. The imagers employ filters measuring OH Meinel (6, 2) and O2 Atmospheric (0, 1) band emission intensities and temperatures, as well as atmospheric gravity wave parameters. Airglow imaging provides a unique means by which to study many wave-related phenomena in the 80 to 100 km altitude regime. Observations reveal quasi-monochromatic disturbances associated with atmospheric gravity waves (AGWs) as well as small-scale instabilities (e.g., ripples). The airglow imager located at Adelaide captured the unusual occurrence of a reflected gravity wave on the night of Aug 1, 2008. Subsequent examination of SABER temperature profiles over the site show extremely cold mesopause temperatures, near 120K, over the observation site near this time. Although such temperatures are common in summertime at high latitudes, their occurrence at midlatitudes is believed to be relatively uncommon. We explore the conditions responsible for the bright, reflecting wave feature observed in the airglow images. We also explore the frequency of cold temperatures observed by the SABER instrument and compare to the observations of cold temperatures found in airglow images.

  2. Performance measurements of multilayer insulation at variable cold temperature

    Science.gov (United States)

    Funke, Thomas; Haberstroh, Christoph

    2012-06-01

    Multilayer insulation (MLI) is commonly used in most cryogenic devices such as LHe-cryostats or superconductive cables. Typically thermal performance measurements have been carried out using bath cryostats. Inherent to all this devices is a fixed cold temperature at the boiling point of the particular cryogenic liquid. A recent approach for cryogenic pressure vessels covers a broad temperature range, i.e. hydrogen storage from 20 K to ambient temperature. Thus, a new calorimeter cryostat has been designed at TU Dresden to meet these requirements. The design as a flow cryostat allows the measurement of the thermal performance with variable cold temperature between 20 K and 300 K. It can be operated in vertical as well as in horizontal orientation. The insulation material is wrapped around a nearly isothermal cylinder which is held at the desired temperature by a cooling fluid. Preferably LHe respectively helium cold gas is used. Several design features reduce undesired interference errors. It is reported about design and equipment of this cryostat plus first experiences in operation

  3. Extreme temperature packaging: challenges and opportunities

    Science.gov (United States)

    Johnson, R. Wayne

    2016-05-01

    Consumer electronics account for the majority of electronics manufactured today. Given the temperature limits of humans, consumer electronics are typically rated for operation from -40°C to +85°C. Military applications extend the range to -65°C to +125°C while underhood automotive electronics may see +150°C. With the proliferation of the Internet of Things (IoT), the goal of instrumenting (sensing, computation, transmission) to improve safety and performance in high temperature environments such as geothermal wells, nuclear reactors, combustion chambers, industrial processes, etc. requires sensors, electronics and packaging compatible with these environments. Advances in wide bandgap semiconductors (SiC and GaN) allow the fabrication of high temperature compatible sensors and electronics. Integration and packaging of these devices is required for implementation into actual applications. The basic elements of packaging are die attach, electrical interconnection and the package or housing. Consumer electronics typically use conductive adhesives or low melting point solders for die attach, wire bonds or low melting solder for electrical interconnection and epoxy for the package. These materials melt or decompose in high temperature environments. This paper examines materials and processes for high temperature packaging including liquid transient phase and sintered nanoparticle die attach, high melting point wires for wire bonding and metal and ceramic packages. The limitations of currently available solutions will also be discussed.

  4. Effects of cold water immersion on lower extremity joint biomechanics during running.

    Science.gov (United States)

    Fukuchi, Claudiane Arakaki; da Rocha, Emmanuel Souza; Stefanyshyn, Darren John

    2015-01-01

    The purpose of this study was to identify the influence of cryotherapy on lower extremity running biomechanics. Twenty-six healthy male volunteers were randomised into two intervention groups: cold water (cold water at ~11°C) or tepid water (tepid water at ~26°C). They were required to run at 4.0 ± 0.2 m · s(-1) before and after they underwent water immersion for 20 min. Differences between pre- and post-intervention were used to compare the influence of water intervention during running. Peak joint angles, peak joint moments, peak ground reaction forces (GRF) and contact time (CT) were calculated using three-dimensional gait analysis. Independent t-tests were applied with a significant alpha level set at 0.05. Decreased peak propulsive and vertical GRF, decreased plantarflexion moments, increased hip flexion angle and longer CT were observed following cold water immersion. Although cold water immersion (cryotherapy) affected the running movement, none of the alterations have been related to running biomechanical patterns associated with injuries. Therefore, our results indicated that cold water immersion appears safe prior to running activities.

  5. Electronic Modeling and Design for Extreme Temperatures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We are developing CAD tools, models and methodologies for electronics design for circuit operation in extreme environments with focus on very low temperatures...

  6. Temperature extremes in Western Europe and associated atmospheric anomalies

    Science.gov (United States)

    Carvalho, V. A.; Santos, J. A.

    2009-09-01

    This worḱs focal point is the analysis of temperature extremes over Western Europe in the period 1957-2007 and their relationship to large-scale anomalies in the atmospheric circulation patterns. The study is based on temperature daily time series recorded at a set of meteorological stations covering the target area. The large-scale anomalies are analyzed using data from the National Centers for Environmental Prediction reanalysis project. Firstly, a preliminary statistical analysis was undertaken in order to identify data gaps and erroneous values and to check the homogeneity of the time series, using not only elementary statistical approaches (e.g., chronograms, box-plots, scatter-plots), but also a set of non-parametric statistical tests particularly suitable for the analysis of monthly and seasonal mean temperature time series (e.g., Wald-Wolfowitz serial correlation test, Spearman and Mann-Kendall trend tests). Secondly, based on previous results, a selection of the highest quality time series was carried out. Aiming at identifying temperature extremes, we then proceed to the isolation of months with temperature values above or below pre-selected thresholds based on the empirical distribution of each time series. In particular, thresholds are based on percentiles specifically computed for each individual temperature record (data adaptive) and not on fixed values. As a result, a calendar of extremely high and extremely low monthly mean temperatures is obtained and the large-scale atmospheric conditions during each extreme are analyzed. Several atmospheric fields are considered in this study (e.g., 2-m maximum and minimum air temperature, sea level pressure, geopotential height, zonal and meridional wind components, vorticity, relative humidity) at different isobaric levels. Results show remarkably different synoptic conditions for temperature extremes in different parts of Western Europe, highlighting the different dynamical mechanisms underlying their

  7. Trends in Mediterranean gridded temperature extremes and large-scale circulation influences

    Directory of Open Access Journals (Sweden)

    D. Efthymiadis

    2011-08-01

    Full Text Available Two recently-available daily gridded datasets are used to investigate trends in Mediterranean temperature extremes since the mid-20th century. The underlying trends are found to be generally consistent with global trends of temperature and their extremes: cold extremes decrease and warm/hot extremes increase. This consistency is better manifested in the western part of the Mediterranean where changes are most pronounced since the mid-1970s. In the eastern part, a cooling is observed, with a near reversal in the last two decades. This inter-basin discrepancy is clearer in winter, while in summer changes are more uniform and the west-east difference is restricted to the rate of increase of warm/hot extremes, which is higher in central and eastern parts of the Mediterranean over recent decades. Linear regression and correlation analysis reveals some influence of major large-scale atmospheric circulation patterns on the occurrence of these extremes – both in terms of trend and interannual variability. These relationships are not, however, able to account for the most striking features of the observations – in particular the intensification of the increasing trend in warm/hot extremes, which is most evident over the last 15–20 yr in the Central and Eastern Mediterranean.

  8. Elevated Temperature and CO2 Stimulate Late-Season Photosynthesis But Impair Cold Hardening in Pine.

    Science.gov (United States)

    Chang, Christine Y; Fréchette, Emmanuelle; Unda, Faride; Mansfield, Shawn D; Ensminger, Ingo

    2016-10-01

    Rising global temperature and CO2 levels may sustain late-season net photosynthesis of evergreen conifers but could also impair the development of cold hardiness. Our study investigated how elevated temperature, and the combination of elevated temperature with elevated CO2, affected photosynthetic rates, leaf carbohydrates, freezing tolerance, and proteins involved in photosynthesis and cold hardening in Eastern white pine (Pinus strobus). We designed an experiment where control seedlings were acclimated to long photoperiod (day/night 14/10 h), warm temperature (22°C/15°C), and either ambient (400 μL L(-1)) or elevated (800 μmol mol(-1)) CO2, and then shifted seedlings to growth conditions with short photoperiod (8/16 h) and low temperature/ambient CO2 (LTAC), elevated temperature/ambient CO2 (ETAC), or elevated temperature/elevated CO2 (ETEC). Exposure to LTAC induced down-regulation of photosynthesis, development of sustained nonphotochemical quenching, accumulation of soluble carbohydrates, expression of a 16-kD dehydrin absent under long photoperiod, and increased freezing tolerance. In ETAC seedlings, photosynthesis was not down-regulated, while accumulation of soluble carbohydrates, dehydrin expression, and freezing tolerance were impaired. ETEC seedlings revealed increased photosynthesis and improved water use efficiency but impaired dehydrin expression and freezing tolerance similar to ETAC seedlings. Sixteen-kilodalton dehydrin expression strongly correlated with increases in freezing tolerance, suggesting its involvement in the development of cold hardiness in P. strobus Our findings suggest that exposure to elevated temperature and CO2 during autumn can delay down-regulation of photosynthesis and stimulate late-season net photosynthesis in P. strobus seedlings. However, this comes at the cost of impaired freezing tolerance. Elevated temperature and CO2 also impaired freezing tolerance. However, unless the frequency and timing of extreme low-temperature

  9. Return Levels of Temperature Extremes in Southern Pakistan

    Science.gov (United States)

    Zahid, Maida; Lucarini, Valerio; Blender, Richard; Caterina Bramati, Maria

    2017-04-01

    Southern Pakistan (Sindh) is one of the hottest regions in the world and is highly vulnerable to temperature extremes. In order to improve rural and urban planning, information about the recurrence of temperature extremes is required. In this work, return levels of the daily maximum temperature Tmax are estimated, as well as the daily maximum wet-bulb temperature TWmax extremes. The method used is the Peak Over Threshold (POT) and it represents a novelty among the approaches previously used for similar studies in this region. Two main datasets are analyzed: temperatures observed in nine meteorological stations in southern Pakistan from 1980 to 2013, and the ERA Interim data for the nearest corresponding locations. The analysis provides the 2, 5, 10, 25, 50 and 100-year Return Levels (RLs) of temperature extremes. The 90% quantile is found to be a suitable threshold for all stations. We find that the RLs of the observed Tmax are above 50°C in northern stations, and above 45°C in the southern stations. The RLs of the observed TWmax exceed 35°C in the region, which is considered as a limit of survivability. The RLs estimated from the ERA Interim data are lower by 3°C to 5°C than the RLs assessed for the nine meteorological stations. A simple bias correction applied to ERA Interim data improves the RLs remarkably, yet discrepancies are still present. The results have potential implications for the risk assessment of extreme temperatures in Sindh.

  10. Cold fronts in the Colombian Caribbean Sea and their relationship to extreme wave events

    Science.gov (United States)

    Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

    2013-11-01

    Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of the Instituto de Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and the Centro de Investigación en Oceanografía y Meteorología of Colombia (CIOH, based on its initials in Spanish) during the last 16 yr. The highest number of cold fronts was observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was observed and the highest number of fronts occurred in 2010 (20 in total); moreover, an annual strong relationship between the maximum average wave values and the cold fronts in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the

  11. Impact of temperature and precipitation extremes on the flowering dates of four German wildlife shrub species

    Science.gov (United States)

    Siegmund, Jonatan F.; Wiedermann, Marc; Donges, Jonathan F.; Donner, Reik V.

    2016-10-01

    Ongoing climate change is known to cause an increase in the frequency and amplitude of local temperature and precipitation extremes in many regions of the Earth. While gradual changes in the climatological conditions have already been shown to strongly influence plant flowering dates, the question arises if and how extremes specifically impact the timing of this important phenological phase. Studying this question calls for the application of statistical methods that are tailored to the specific properties of event time series. Here, we employ event coincidence analysis, a novel statistical tool that allows assessing whether or not two types of events exhibit similar sequences of occurrences in order to systematically quantify simultaneities between meteorological extremes and the timing of the flowering of four shrub species across Germany. Our study confirms previous findings of experimental studies by highlighting the impact of early spring temperatures on the flowering of the investigated plants. However, previous studies solely based on correlation analysis do not allow deriving explicit estimates of the strength of such interdependencies without further assumptions, a gap that is closed by our analysis. In addition to direct impacts of extremely warm and cold spring temperatures, our analysis reveals statistically significant indications of an influence of temperature extremes in the autumn preceding the flowering.

  12. Effects of extreme spring temperatures on phenology: a case study from Munich and Ingolstadt

    Science.gov (United States)

    Jochner, Susanne; Menzel, Annette

    2010-05-01

    Extreme events - e.g. warm spells or heavy precipitation events - are likely to increase in the future both in frequency and intensity. Therefore, research on extreme events gains new importance; also in terms of plant development which is mostly triggered by temperatures. An arising question is how plants respond to an extreme warm spell when following an extreme cold winter season. This situation could be studied in spring 2009 in the greater area of Munich and Ingolstadt by phenological observations of flowering and leaf unfolding of birch (Betula pendula L.) and flowering of horse chestnut (Aesculus hippocastanum L.). The long chilling period of winter 2008 and spring 2009 was followed by an immediate strong forcing of flowering and leaf unfolding, especially for birch. This extreme weather situation diminished the difference between urban and rural dates of onset. Another important fact that could be observed in the proceeding period of December 2008 to April 2009 was the reduced temperature difference among urban and rural sites (urban heat island effect). Long-term observations (1951-2008) of the phenological network of the German Meteorological Service (DWD) were used to identify years with reduced urban-rural differences between onset times in the greater area of Munich in the past. Statistical analyses were conducted in order to answer the question whether the sequence of extreme warm and cold events leads to a decreased difference in phenological onset times or if this behaviour can be attributed to extreme warm springs themselves or to the decreased urban heat island effect which is mostly affected by general atmospheric circulation patterns.

  13. Murder or Not? Cold Temperature Makes Criminals Appear to Be Cold-Blooded and Warm Temperature to Be Hot-Headed

    OpenAIRE

    Christine Gockel; Kolb, Peter M.; Lioba Werth

    2014-01-01

    Temperature-related words such as cold-blooded and hot-headed can be used to describe criminal behavior. Words associated with coldness describe premeditated behavior and words associated with heat describe impulsive behavior. Building on recent research about the close interplay between physical and interpersonal coldness and warmth, we examined in a lab experiment how ambient temperature within a comfort zone influences judgments of criminals. Participants in rooms with low temperature rega...

  14. Towards constraining extreme temperature projections of the CMIP5 ensemble

    Science.gov (United States)

    Vogel, Martha-Marie; Orth, René; Isabelle Seneviratne, Sonia

    2016-04-01

    The frequency and intensity of heat waves is expected to change in future in response to global warming. Given the severe impacts of heat waves on ecosystems and society it is important to understand how and where they will intensify. Projections of extreme hot temperatures in the IPCC AR5 model ensemble show large uncertainties for projected changes of extreme temperatures in particular in Central Europe. In this region land-atmosphere coupling can contribute substantially to the development of heat waves. This coupling is also subject to change in future, while model projections display considerable spread. In this work we link projections of changes in extreme temperatures and of changes in land-atmosphere interactions with a particular focus on Central Europe. Uncertainties in projected extreme temperatures can be partly explained by different projected changes of the interplay between latent heat and temperature as well as soil moisture. Given the considerable uncertainty in land-atmosphere coupling representation already in the current climate, we furthermore employ observational data sets to constrain the model ensemble, and consequently the extreme temperature projections.

  15. Body temperature regulation during acclimation to cold and hypoxia in rats.

    Science.gov (United States)

    Cadena, V; Tattersall, G J

    2014-12-01

    Extreme environmental conditions present challenges for thermoregulation in homoeothermic organisms such as mammals. Such challenges are exacerbated when two stressors are experienced simultaneously and each stimulus evokes opposing physiological responses. This is the case of cold, which induces an increase in thermogenesis, and hypoxia, which suppresses metabolism conserving oxygen and preventing hypoxaemia. As an initial approach to understanding the thermoregulatory responses to cold and hypoxia in a small mammal, we explored the effects of acclimation to these two stressors on the body temperature (Tb) and the daily and ultradian Tb variations of Sprague-Dawley rats. As Tb is influenced by sleep-wake cycles, these Tb variations reflect underlying adjustments in set-point and thermosensitivity. The Tb of rats decreased precipitously during initial hypoxic exposure which was more pronounced in cold (Tb=33.4 ± 0.13) than in room temperature (Tb=35.74 ± 0.17) conditions. This decline was followed by an increase in Tb stabilising at a new level ~0.5°C and ~1.4°C below normoxic values at room and cold temperatures, respectively. Daily Tb variations were blunted during hypoxia with a greater effect in the cold. Ultradian Tb variations exhibited daily rhythmicity that disappeared under hypoxia, independent of ambient temperature. The adjustments in Tb during hypoxia and/or cold are in agreement with the hypothesis that an initial decrease in the Tb set-point is followed by its partial re-establishment with chronic hypoxia. This rebound of the Tb set-point might reflect cellular adjustments that would allow animals to better deal with low oxygen conditions, diminishing the drive for a lower Tb set-point. Cold and hypoxia are characteristic of high altitude environments. Understanding how mammals cope with changes in oxygen and temperature will shed light into their ability to colonize new environments along altitudinal clines and increase our understanding of how

  16. Finger and toe temperature response to cold water and cold air exposure

    NARCIS (Netherlands)

    Struijs, N.R. van der; Es, E.M. van; Raymann, R.J.E.M.; Daanen, H.A.M.

    2008-01-01

    Introduction: Subjects with a weak cold-induced vasodilatation response (CIVD) to experimental cold-water immersion of the fingers in a laboratory setting have been shown to have a higher risk for local cold injuries when exposed to cold in real life. Most of the cold injuries in real life, however,

  17. Spatiotemporal distribution characteristics and attribution of extreme regional low temperature event

    Institute of Scientific and Technical Information of China (English)

    封泰晨; 张珂铨; 苏海晶; 王晓娟; 龚志强; 张文煜

    2015-01-01

    Based on an objective identification technique for regional low temperature event (OITRLTE), the daily minimum temperature in China has been detected from 1960 to 2013. During this period, there were 60 regional extreme low temperature events (ERLTEs), which are included in the 690 regional low temperature events (RLTEs). The 60 ERLTEs are analyzed in this paper. The results show that in the last 50 years, the intensity of the ERLTEs has become weak;the number of lasted days has decreased;and, the affected area has become small. However, that situation has changed in this century. In terms of spatial distribution, the high intensity regions are mainly in Northern China while the high frequency regions concentrate in Central and Eastern China. According to the affected area of each event, the 60 ERLTEs are classified into six types. The atmospheric circulation background fields which correspond to these types are also analyzed. The results show that, influenced by stronger blocking highs of Ural and Lake Baikal, as well as stronger southward polar vortex and East Asia major trough at 500-hPa geopotential height, cold air from high latitudes is guided to move southward and abnormal northerly winds at 850 hPa makes the cold air blow into China along diverse paths, thereby forming different types of regional extreme low temperatures in winter.

  18. Multidecadal changes in the relationship between extreme temperature events in Uruguay and the general atmospheric circulation

    Energy Technology Data Exchange (ETDEWEB)

    Renom, Madeleine; Barreiro, Marcelo [Universidad de la Republica, Unidad de Ciencias de la Atmosfera, Instituto de Fisica, Facultad de Ciencias, Montevideo (Uruguay); Rusticucci, Matilde [Universidad de Buenos Aires, Departamento de Ciencias de la Atmosfera y los Oceanos, Facultad de Ciencias Exactas y Naturales, Buenos Aires (Argentina)

    2011-12-15

    We analyze changes in the relationship between extreme temperature events and the large scale atmospheric circulation before and after the 1976 climate shift. To do so we first constructed a set of two temperature indices that describe the occurrence of warm nights (TN90) and cold nights (TN10) based on a long daily observed minimum temperature database that spans the period 1946-2005, and then divided the period into two subperiods of 30 years each (1946-1975 and 1976-2005). We focus on summer (TN10) and winter (TN90) seasons. During austral summer before 1976 the interannual variability of cold nights was characterized by a negative phase of the Southern Annular Mode (SAM) with a cyclonic anomaly centered off Uruguay that favoured the entrance of cold air from the south. After 1976 cold nights are associated not with the SAM, but with an isolated vortex at upper levels over South Eastern South America. During austral winter before 1976, the El Nino phenomenon dominated the interannual variability of warm nights through an increase in the northerly warm flow into Uruguay. However, after 1976 the El Nino connection weakened and the variability of warm nights is dominated by a barotropic anticyclonic anomaly located in the South Atlantic and a low pressure center over South America. This configuration also strengthens the northward flow of warm air into Uruguay. Our results suggest that changes in El Nino evolution after 1976 may have played a role in altering the relationship between temperature extreme events in Uruguay and the atmospheric circulation. (orig.)

  19. Protein stability and enzyme activity at extreme biological temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Feller, Georges, E-mail: gfeller@ulg.ac.b [Laboratory of Biochemistry, Centre for Protein Engineering, Institute of Chemistry B6a, University of Liege, B-4000 Liege (Belgium)

    2010-08-18

    Psychrophilic microorganisms thrive in permanently cold environments, even at subzero temperatures. To maintain metabolic rates compatible with sustained life, they have improved the dynamics of their protein structures, thereby enabling appropriate molecular motions required for biological activity at low temperatures. As a consequence of this structural flexibility, psychrophilic proteins are unstable and heat-labile. In the upper range of biological temperatures, thermophiles and hyperthermophiles grow at temperatures > 100 {sup 0}C and synthesize ultra-stable proteins. However, thermophilic enzymes are nearly inactive at room temperature as a result of their compactness and rigidity. At the molecular level, both types of extremophilic proteins have adapted the same structural factors, but in opposite directions, to address either activity at low temperatures or stability in hot environments. A model based on folding funnels is proposed accounting for the stability-activity relationships in extremophilic proteins. (topical review)

  20. Daily extreme temperature multifractals in Catalonia (NE Spain)

    Energy Technology Data Exchange (ETDEWEB)

    Burgueño, A. [Departament d' Astronomia i Meteorologia, Universitat de Barcelona, Barcelona (Spain); Lana, X., E-mail: francisco.javier.lana@upc.edu [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Serra, C. [Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Barcelona (Spain); Martínez, M.D. [Departament de Física Aplicada, Universitat Politècnica de Catalunya, Barcelona (Spain)

    2014-02-01

    The multifractal character of the daily extreme temperatures in Catalonia (NE Spain) is analyzed by means of the multifractal detrended fluctuation analysis (MF-DFA) applied to 65 thermometric records covering years 1950–2004. Although no clear spatial patterns of the multifractal spectrum parameters appear, factor scores deduced from Principal Component analysis indicate some signs of spatial gradients. Additionally, the daily extreme temperature series are classified depending on their complex time behavior, through four multifractal parameters (Hurst exponent, Hölder exponent with maximum spectrum, spectrum asymmetry and spectrum width). As a synthesis of the three last parameters, a basic measure of complexity is proposed through a normalized Complexity Index. Its regional behavior is found to be free of geographical dependences. This index represents a new step towards the description of the daily extreme temperatures complexity.

  1. Can a regional climate model reproduce observed extreme temperatures?

    Directory of Open Access Journals (Sweden)

    Peter F. Craigmile

    2013-10-01

    Full Text Available Using output from a regional Swedish climate model and observations from the Swedish synoptic observational network, we compare seasonal minimum temperatures from model output and observations using marginal extreme value modeling techniques. We make seasonal comparisons using generalized extreme value models and empirically estimate the shift in the distribution as a function of the regional climate model values, using the Doksum shift function. Spatial and temporal comparisons over south central Sweden are made by building hierarchical Bayesian generalized extreme value models for the observed minima and regional climate model output. Generally speaking the regional model is surprisingly well calibrated for minimum temperatures. We do detect a problem in the regional model to produce minimum temperatures close to 0◦C. The seasonal spatial effects are quite similar between data and regional model. The observations indicate relatively strong warming, especially in the northern region. This signal is present in the regional model, but is not as strong.

  2. Extreme temperature days and potential impacts in Southern Europe

    Directory of Open Access Journals (Sweden)

    A. Cardil

    2014-06-01

    Full Text Available Extreme temperature events have consequences for human health and mortality, forest disturbance patterns, agricultural productivity, and the economic repercussions of these consequences combined. To gain insight into whether extreme temperature events are changing in light of global climate dynamics, the annual numbers of high temperature days (those with temperatures higher than 20, 22.5 and 25 °C at 850 hPa were analyzed across Southern Europe from years 1978–2012. A significant increase in the frequency of these days was found in many areas over the time period analyzed, and patterns in the spatial distribution of these changes were identified. We discuss the potential consequences of the increases in high temperature days with regards to forest fire risk, human health, agriculture, energy demands, and some potential economic repercussions.

  3. Impacts of extreme climatic events on the energetics of long-lived vertebrates: the case of the greater flamingo facing cold spells in the Camargue.

    Science.gov (United States)

    Deville, Anne-Sophie; Labaude, Sophie; Robin, Jean-Patrice; Béchet, Arnaud; Gauthier-Clerc, Michel; Porter, Warren; Fitzpatrick, Megan; Mathewson, Paul; Grémillet, David

    2014-10-15

    Most studies analyzing the effects of global warming on wild populations focus on gradual temperature changes, yet it is also important to understand the impact of extreme climatic events. Here we studied the effect of two cold spells (January 1985 and February 2012) on the energetics of greater flamingos (Phoenicopterus roseus) in the Camargue (southern France). To understand the cause of observed flamingo mass mortalities, we first assessed the energy stores of flamingos found dead in February 2012, and compared them with those found in other bird species exposed to cold spells and/or fasting. Second, we evaluated the monthly energy requirements of flamingos across 1980-2012 using the mechanistic model Niche Mapper. Our results show that the body lipids of flamingos found dead in 2012 corresponded to 2.6±0.3% of total body mass, which is close to results found in woodcocks (Scolopax rusticola) that died from starvation during a cold spell (1.7±0.1%), and much lower than in woodcocks which were fed throughout this same cold spell (13.0±2%). Further, Niche Mapper predicted that flamingo energy requirements were highest (+6-7%) during the 1985 and 2012 cold spells compared with 'normal' winters. This increase was primarily driven by cold air temperatures. Overall, our findings strongly suggest that flamingos starved to death during both cold spells. This study demonstrates the relevance of using mechanistic energetics modelling and body condition analyses to understand and predict the impact of extreme climatic events on animal energy balance and winter survival probabilities. © 2014. Published by The Company of Biologists Ltd.

  4. Trends in extreme temperature indices in Huang-Huai-Hai River Basin of China during 1961-2014

    Science.gov (United States)

    Wang, Gang; Yan, Denghua; He, Xiaoyan; Liu, Shaohua; Zhang, Cheng; Xing, Ziqiang; Kan, Guangyuan; Qin, Tianling; Ren, Minglei; Li, Hui

    2017-08-01

    Spatial and temporal characteristics of temperature extremes have been investigated in Huang-Huai-Hai (HHH) region based on the daily series of temperature observations from 162 meteorological stations. A total of 11 indices were used to assess the changes of temperature pattern. Linear trend analyses revealed that the daily maximum temperature (TXx) increased at α = 0.05 level with a magnitude of 0.15 °C per decade on the regional scale during the period of 1961-2014. More pronounced warming trend of the daily minimum temperature (TNn) was detected at a rate of 0.49 °C per decade (α = 0.01 level). Consequently, a decreasing trend of the temperature range of TXx and TNn (extreme temperature range) was observed. The frequency of hot days (TXf90) and annual average of warm events (warm spell duration indicator, WSDI) showed significant increasing trends, while that of cold nights (TNf10) and cold events (cold spell duration indicator, CSDI) showed opposite behaviors. Both warm winter (W-W) and hot summer (H-S) series displayed significant increasing trends at α = 0.01 confidence level. The cold winter (C-W) series showed a decreasing trend at α = 0.01 confidence level, while the cool summer (C-S) series showed a nonsignificant decreasing trend that is not passing the 90% confidence level (α = 0.1). Abrupt increments of warm­related extremes (TXx, TXf90, WSDI) have been detected since 1990s, and a steadily decreasing trend of cold related extremes (TNf10, CSDI) was found since 1970s. Ten hot summers out of 11 and nine warm winters out of 10 occurred after 1990s. Altitude has a large impact on spatial pattern of extreme temperature indices, and the urban heat island effect also has an impact on amplitude of variation in extreme temperature. Trend magnitudes are significantly larger at sites with high altitudes for warm­related indices (TXx, TXf90, WSDI), while those involving cold-related indices (TNn, TNf10) are remarkably larger for stations with low

  5. An imaging radiometer for measurement of lunar polar cold trap temperatures

    Science.gov (United States)

    Lucey, Paul G.; Blasius, Karl R.; Bussey, Ben; Hoelter, Roger L.; Gillis, Jeffrey J.; Lawson, Stefanie L.; Mellon, Michael; Spencer, John; Urquhart, Mary; Vasavada, Ashwin R.; Wang, Angel T.

    2004-12-01

    The LRO Radiometer Investigation is an experiment proposed for NASA"s Lunar Reconnaisance Orbiter mission that will use a simple but extremely sensitive radiometer to measure the temperatures of the region of permanent shade at the lunar poles. Temperature governs the ability of these surfaces to act as cold traps, and tightly constrains the identity and lifetimes of potential volatile resources. The LRO Radiometer will also measure the night time temperature of the Moon, and use the extensive modeling experience of the team to use these data to produce maps of meter-scale rocks that constitute a significant hazard to landing and operations. The LRO Radiometer also supports LRO objectives by measuring the global abundance of meter scale rocks at 1 km resolution. This measurement is accomplished in four (4) months of observations.

  6. Evaluation of dynamically downscaled extreme temperature using a spatially-aggregated generalized extreme value (GEV) model

    Science.gov (United States)

    Wang, Jiali; Han, Yuefeng; Stein, Michael L.; Kotamarthi, Veerabhadra R.; Huang, Whitney K.

    2016-11-01

    The weather research and forecast (WRF) model downscaling skill in extreme maximum daily temperature is evaluated by using the generalized extreme value (GEV) distribution. While the GEV distribution has been used extensively in climatology and meteorology for estimating probabilities of extreme events, accurately estimating GEV parameters based on data from a single pixel can be difficult, even with fairly long data records. This work proposes a simple method assuming that the shape parameter, the most difficult of the three parameters to estimate, does not vary over a relatively large region. This approach is applied to evaluate 31-year WRF-downscaled extreme maximum temperature through comparison with North American regional reanalysis (NARR) data. Uncertainty in GEV parameter estimates and the statistical significance in the differences of estimates between WRF and NARR are accounted for by conducting a novel bootstrap procedure that makes no assumption of temporal or spatial independence within a year, which is especially important for climate data. Despite certain biases over parts of the United States, overall, WRF shows good agreement with NARR in the spatial pattern and magnitudes of GEV parameter estimates. Both WRF and NARR show a significant increase in extreme maximum temperature over the southern Great Plains and southeastern United States in January and over the western United States in July. The GEV model shows clear benefits from the regionally constant shape parameter assumption, for example, leading to estimates of the location and scale parameters of the model that show coherent spatial patterns.

  7. Extreme temperatures and precipitation in Poland. An evaluation attempt

    Energy Technology Data Exchange (ETDEWEB)

    Ustrnul, Zbigniew [Institute of Meteorology and Water Management, Krakow (Poland); Wypych, Agnieszka; Kosowski, Marek [Jagiellonian Univ., Krakow (Poland)

    2012-02-15

    Summer (JJA) and winter (DJF) temperature extremes and summer (JJA) precipitation extremes in Poland that occurred in the years 1951-2006 are analyzed in this paper. Diurnal extreme values of air temperature (Tmax, Tmin) and diurnal precipitation totals (P) are considered. The data was obtained from 54 meteorological stations. Extreme values were identified based on different methodological approaches. Advantages and disadvantages of selected methods are shown with respect to both temporal and spatial variability of the data. The differences obtained as a result of the applied criteria confirm that the method of percentiles seems to be the most suitable one to be used in spatial analysis. This is especially relevant in areas with a relatively high variability of absolute values. When it comes to analyses of multi-annual trends, the criterion used plays a less significant role. Regardless of the method, there is a certain direction of changes that is maintained, although their magnitudes may be different. It may be concluded from the conducted analyses that for the full evaluation of both spatial variability and temporal variability of weather extremes, a variety of methods and criteria for identifying extreme values, should be considered. They may significantly influence the final results. (orig.)

  8. Statistical Downscaling of Summer Temperature Extremes in Northern China

    Institute of Scientific and Technical Information of China (English)

    FAN Lijun; Deliang CHEN; FU Congbin; YAN Zhongwei

    2013-01-01

    Two approaches of statistical downscaling were applied to indices of temperature extremes based on percentiles of daily maximum and minimum temperature observations at Beijing station in summer during 1960-2008.One was to downscale daily maximum and minimum temperatures by using EOF analysis and stepwise linear regression at first,then to calculate the indices of extremes; the other was to directly downscale the percentile-based indices by using seasonal large-scale temperature and geo-potential height records.The cross-validation results showed that the latter approach has a better performance than the former.Then,the latter approach was applied to 48 meteorological stations in northern China.The crossvalidation results for all 48 stations showed close correlation between the percentile-based indices and the seasonal large-scale variables.Finally,future scenarios of indices of temperature extremes in northern China were projected by applying the statistical downscaling to Hadley Centre Coupled Model Version 3 (HadCM3) simulations under the Representative Concentration Pathways 4.5 (RCP 4.5) scenario of the Fifth Coupled Model Inter-comparison Project (CMIP5).The results showed that the 90th percentile of daily maximum temperatures will increase by about 1.5℃,and the 10th of daily minimum temperatures will increase by about 2℃ during the period 2011-35 relative to 1980-99.

  9. Trends in temperature extremes over nine integrated agricultural regions in China, 1961-2011

    Science.gov (United States)

    Wu, Xushu; Wang, Zhaoli; Zhou, Xiaowen; Lai, Chengguang; Chen, Xiaohong

    2016-06-01

    By characterizing the patterns of temperature extremes over nine integrated agricultural regions (IARs) in China from 1961 to 2011, this study performed trend analyses on 16 extreme temperature indices using a high-resolution (0.5° × 0.5°) daily gridded dataset and the Mann-Kendall method. The results show that annually, at both daytime and nighttime, cold extremes significantly decreased but warm extremes significantly increased across all IARs. Overall, nighttimes tended to warm faster than daytimes. Diurnal temperature ranges (DTR) diminished, apart from the mid-northern Southwest China Region and the mid-Loess Plateau Region. Seasonally, DTR widely diminished across all IARs during the four seasons except for spring. Higher minimum daily minimum temperature (TNn) and maximum daily maximum temperature (TXx), in both summer and winter, were recorded for most IARs except for the Huang-Huai-Hai Region; in autumn, all IARs generally encountered higher TNn and TXx. In all seasons, warming was observed at daytime and nighttime but, again, nighttimes warmed faster than daytimes. The results also indicate a more rapid warming trend in Northern and Western China than in Southern and Eastern China, with accelerated warming at high elevations. The increases in TNn and TXx might cause a reduction in agriculture yield in spring over Northern China, while such negative impact might occur in Southern China during summer. In autumn and winter, however, the negative impact possibly occurred in most of the IARs. Moreover, increased TXx in the Pearl River Delta and Yangtze River Delta is possibly related to rapid local urbanization. Climatically, the general increase in temperature extremes across Chinese IARs may be induced by strengthened Northern Hemisphere Subtropical High or weakened Northern Hemisphere Polar Vortex.

  10. Climate Change and Fetal Health: The Impacts of Exposure to Extreme Temperatures in New York City

    Science.gov (United States)

    Ngo, Nicole S.; Horton, Radley M.

    2015-01-01

    Background: Climate change is projected to increase the frequency, intensity, and duration of heat waves while reducing cold extremes, yet few studies have examined the relationship between temperature and fetal health. Objectives: We estimate the impacts of extreme temperatures on birth weight and gestational age in Manhattan, a borough in New York City, and explore differences by socioeconomic status (SES). Methods: We combine average daily temperature from 1985 to 2010 with birth certificate data in Manhattan for the same time period. We then generate 33 downscaled climate model time series to project impacts on fetal health. Results: We find exposure to an extra day where average temperature 25 F and 85 F during pregnancy is associated with a 1.8 and 1.7 g (respectively) reduction in birth weight, but the impact varies by SES, particularly for extreme heat, where teen mothers seem most vulnerable. We find no meaningful, significant effect on gestational age. Using projections of temperature from these climate models, we project average net reductions in birth weight in the 2070- 2099 period of 4.6 g in the business-as-usual scenario. Conclusions: Results suggest that increasing heat events from climate change could adversely impact birth weight and vary by SES.

  11. Climate Change and Fetal Health: The Impacts of Exposure to Extreme Temperatures in New York City

    Science.gov (United States)

    Ngo, Nicole S.; Horton, Radley M.

    2015-01-01

    Background: Climate change is projected to increase the frequency, intensity, and duration of heat waves while reducing cold extremes, yet few studies have examined the relationship between temperature and fetal health. Objectives: We estimate the impacts of extreme temperatures on birth weight and gestational age in Manhattan, a borough in New York City, and explore differences by socioeconomic status (SES). Methods: We combine average daily temperature from 1985 to 2010 with birth certificate data in Manhattan for the same time period. We then generate 33 downscaled climate model time series to project impacts on fetal health. Results: We find exposure to an extra day where average temperature 25 F and 85 F during pregnancy is associated with a 1.8 and 1.7 g (respectively) reduction in birth weight, but the impact varies by SES, particularly for extreme heat, where teen mothers seem most vulnerable. We find no meaningful, significant effect on gestational age. Using projections of temperature from these climate models, we project average net reductions in birth weight in the 2070- 2099 period of 4.6 g in the business-as-usual scenario. Conclusions: Results suggest that increasing heat events from climate change could adversely impact birth weight and vary by SES.

  12. Cold Stress

    Science.gov (United States)

    ... Publications and Products Programs Contact NIOSH NIOSH COLD STRESS Recommend on Facebook Tweet Share Compartir Workers who ... cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that ...

  13. Murder or not? Cold temperature makes criminals appear to be cold-blooded and warm temperature to be hot-headed.

    Directory of Open Access Journals (Sweden)

    Christine Gockel

    Full Text Available Temperature-related words such as cold-blooded and hot-headed can be used to describe criminal behavior. Words associated with coldness describe premeditated behavior and words associated with heat describe impulsive behavior. Building on recent research about the close interplay between physical and interpersonal coldness and warmth, we examined in a lab experiment how ambient temperature within a comfort zone influences judgments of criminals. Participants in rooms with low temperature regarded criminals to be more cold-blooded than participants in rooms with high temperature. Specifically, they were more likely to attribute premeditated crimes, ascribed crimes resulting in higher degrees of penalty, and attributed more murders to criminals. Likewise, participants in rooms with high temperature regarded criminals to be more hot-headed than participants in rooms with low temperature: They were more likely to attribute impulsive crimes. Results imply that cognitive representations of temperature are closely related to representations of criminal behavior and attributions of intent.

  14. Murder or not? Cold temperature makes criminals appear to be cold-blooded and warm temperature to be hot-headed.

    Science.gov (United States)

    Gockel, Christine; Kolb, Peter M; Werth, Lioba

    2014-01-01

    Temperature-related words such as cold-blooded and hot-headed can be used to describe criminal behavior. Words associated with coldness describe premeditated behavior and words associated with heat describe impulsive behavior. Building on recent research about the close interplay between physical and interpersonal coldness and warmth, we examined in a lab experiment how ambient temperature within a comfort zone influences judgments of criminals. Participants in rooms with low temperature regarded criminals to be more cold-blooded than participants in rooms with high temperature. Specifically, they were more likely to attribute premeditated crimes, ascribed crimes resulting in higher degrees of penalty, and attributed more murders to criminals. Likewise, participants in rooms with high temperature regarded criminals to be more hot-headed than participants in rooms with low temperature: They were more likely to attribute impulsive crimes. Results imply that cognitive representations of temperature are closely related to representations of criminal behavior and attributions of intent.

  15. Nerve conduction studies in upper extremities: skin temperature corrections.

    Science.gov (United States)

    Halar, E M; DeLisa, J A; Soine, T L

    1983-09-01

    The relationship of skin to near nerve (NN) temperature and to nerve conduction velocity (NCV) and distal latency (DL) was studied in 34 normal adult subjects before and after cooling both upper extremities. Median and ulnar motor and sensory NCV, DL, and NN temperature were determined at ambient temperature (mean X skin temp = 33 C) and after cooling, at approximately 26, 28, and 30 C of forearm skin temperature. Skin temperatures on the volar side of the forearm, wrist, palm, and fingers and NN temperature at the forearm, midpalm, and thenar or hypothenar eminence were compared with respective NCV and DL. Results showed a significant linear correlation between skin temperature and NN temperature at corresponding sites (r2 range, 0.4-0.84; p less than 0.005). Furthermore, both skin and NN temperatures correlated significantly with respective NCV and DL. Midline wrist skin temperature showed the best correlation to NCV and DL. Median motor and sensory NCV were altered 1.5 and 1.4m/sec/C degree and their DL 0.2 msec/C degree of wrist skin temperature change, respectively. Ulnar motor and sensory NCV were changed 2.1 and 1.6m/sec/C degree respectively, and 0.2 msec/C degree wrist temperature for motor and sensory DL. Average ambient skin temperature at the wrist (33 C) was used as a standard skin temperature in the temperature correction formula: NCV or DL(temp corrected) = CF(Tst degree - Tm degree) + obtained NCV or DL, where Tst = 33 C for wrist, Tm = the measured skin temperature, and CF = correction factor of tested nerve. Use of temperature correction formula for NCV and DL is suggested in patients with changed wrist skin temperature outside 29.6-36.4C temperature range.

  16. Impact of soil moisture on extreme maximum temperatures in Europe

    Directory of Open Access Journals (Sweden)

    Kirien Whan

    2015-09-01

    Full Text Available Land-atmosphere interactions play an important role for hot temperature extremes in Europe. Dry soils may amplify such extremes through feedbacks with evapotranspiration. While previous observational studies generally focused on the relationship between precipitation deficits and the number of hot days, we investigate here the influence of soil moisture (SM on summer monthly maximum temperatures (TXx using water balance model-based SM estimates (driven with observations and temperature observations. Generalized extreme value distributions are fitted to TXx using SM as a covariate. We identify a negative relationship between SM and TXx, whereby a 100 mm decrease in model-based SM is associated with a 1.6 °C increase in TXx in Southern-Central and Southeastern Europe. Dry SM conditions result in a 2–4 °C increase in the 20-year return value of TXx compared to wet conditions in these two regions. In contrast with SM impacts on the number of hot days (NHD, where low and high surface-moisture conditions lead to different variability, we find a mostly linear dependency of the 20-year return value on surface-moisture conditions. We attribute this difference to the non-linear relationship between TXx and NHD that stems from the threshold-based calculation of NHD. Furthermore the employed SM data and the Standardized Precipitation Index (SPI are only weakly correlated in the investigated regions, highlighting the importance of evapotranspiration and runoff for resulting SM. Finally, in a case study for the hot 2003 summer we illustrate that if 2003 spring conditions in Southern-Central Europe had been as dry as in the more recent 2011 event, temperature extremes in summer would have been higher by about 1 °C, further enhancing the already extreme conditions which prevailed in that year.

  17. Storms or cold fronts? What is really responsible for the extreme waves regime in the Colombian Caribbean coast

    Science.gov (United States)

    Otero, L. J.; Ortiz-Royero, J. C.; Ruiz-Merchan, J. K.; Higgins, A. E.; Henriquez, S. A.

    2015-05-01

    On Friday, 7 March 2009, a 200 m-long section of the tourist pier in Puerto Colombia collapsed under the impact of the waves generated by a cold front in the area. The aim of this study is to determine the contribution and importance of cold fronts and storms on extreme waves in different areas of the Colombian Caribbean to determine the degree of the threat posed by the flood processes to which these coastal populations are exposed and the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the wave's height; therefore, it is necessary to definitively know the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. Using Gumbel's extreme value methodology, the significant height values for the study area were calculated. The methodology was evaluated using data from the re-analysis of the spectral NOAA Wavewatch III (WW3) model for 15 points along the 1600 km of the Colombia Caribbean coast (continental and insular) of the last 15 years. The results demonstrated that the extreme waves caused by tropical cyclones and cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira). In the central area formed by Baja Guajira, Santa Marta, Barranquilla, and Cartagena, the strong influence of cold fronts on extreme waves is evident. On the other hand, in the southern region of the Colombian Caribbean coast, from the Gulf of Morrosquillo to the Gulf of Urabá, even though extreme waves are lower than in the previous regions, extreme waves are dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to its geographic location. The wave heights in the extreme regime are

  18. Storms or cold fronts? What is really responsible for the extreme waves regime in the Colombian Caribbean coast

    Directory of Open Access Journals (Sweden)

    L. J. Otero

    2015-05-01

    Full Text Available On Friday, 7 March 2009, a 200 m-long section of the tourist pier in Puerto Colombia collapsed under the impact of the waves generated by a cold front in the area. The aim of this study is to determine the contribution and importance of cold fronts and storms on extreme waves in different areas of the Colombian Caribbean to determine the degree of the threat posed by the flood processes to which these coastal populations are exposed and the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the wave's height; therefore, it is necessary to definitively know the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. Using Gumbel's extreme value methodology, the significant height values for the study area were calculated. The methodology was evaluated using data from the re-analysis of the spectral NOAA Wavewatch III (WW3 model for 15 points along the 1600 km of the Colombia Caribbean coast (continental and insular of the last 15 years. The results demonstrated that the extreme waves caused by tropical cyclones and cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira. In the central area formed by Baja Guajira, Santa Marta, Barranquilla, and Cartagena, the strong influence of cold fronts on extreme waves is evident. On the other hand, in the southern region of the Colombian Caribbean coast, from the Gulf of Morrosquillo to the Gulf of Urabá, even though extreme waves are lower than in the previous regions, extreme waves are dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to its geographic location. The wave heights in the

  19. Changes in annual temperature and precipitation extremes in the Carpathians since AD 1961

    Science.gov (United States)

    Dumitrescu, Alexandru; Birsan, Marius-Victor; Magdalena Micu, Dana; Cheval, Sorin

    2014-05-01

    The Carpathians are the largest, longest, most twisted and fragmented segment of the Alpine system, stretching between latitudes 44°N and 50°N, and longitudes 17°E and 27°E. This European mountain range is a climatically transitional region between major atmospheric circulation source areas of the Atlantic Ocean, Mediterranean Sea and continental Europe. The region is a European biodiversity hotspot, containing over one third of all European plant species. It is acknowledged that the mountain regions are particularly sensitive and vulnerable to climate change than any other regions located at the same latitudes. Observational studies on the variability and trends of extreme events suggest an overall consensus towards a significant increase in the frequency, duration and intensity of warm extremes in most of these regions, including the Carpathians. 15 core indices, defined by the Expert Team on Climate Change Detection and Indices (ETCCDI), were computed in order to investigate the changes in annual temperature and precipitation extremes, based on their known relevance for the infrastructure, human health and tourism activities in these mountains. The indices were computed from gridded daily datasets of minimum and maximum temperature and precipitation at 0.1° resolution (~10 km), available online within the framework of the project CarpatClim (www.carpatclim-eu.org) for the period 1961-2010. Changes in the annual temperature and precipitation extremes in the last five decades have been identified with the Mann-Kendall non-parametric trend test, at the 90% significance level (two-tail test). The results show decreasing trends in cold-related thermal indices, especially in the number of frost days, and increasing trends in warm-related ones. No consistent trend in precipitation extremes has been found. There is a generally uniform signal of significant increasing trends in the frequency of summer days across the Carpathians, with no obvious differences between

  20. Projected changes in precipitation extremes linked to temperature over Japan

    Science.gov (United States)

    Nayak, S.; Dairaku, K.; Takayabu, I.; Suzuki-Parker, A.

    2015-12-01

    Recent studies have argued that the extreme precipitation intensities are increasing in many regions across the globe due to atmospheric warming. This argument is based on the principle of Clausius-Clapeyron relationship which states that the atmosphere can hold more moisture in warmer air temperature (~7%/°C). In our study, we have investigated the precipitation extremes linked to temperature in current climate (1981-2000) and their projected changes in late 21st century (2081-2100, RCP4.5) over Japan from multi-model ensemble downscaling experiments by three RCMs (NHRCM, NRAMS, WRF) forced by JRA25 as well as three GCMs (CCSM4, MIROC5, MRI-GCM3). To do this, the precipitation intensities of wet days (defined as ≥ 0.05 mm/d) are stratified to different bins with 1°C temperature interval. We have also identified the occurrences of precipitation extremes in different spell durations and associated peak intensities exceeding various thresholds in two climate periods. We found that extreme precipitation intensities are increased by 5 mm/d in future climate for temperatures above 21°C (Fig. 1). Precipitation extremes of higher percentiles are projected to have larger increase rates in future climate scenarios (3-5%/°C in the current climate and 4-6%/°C in the future climate scenarios). The joint probability distribution of wet hours (≥1mm/h) with various peak intensities under future climate scenarios (RCP4.5) of the late 21st century suggests an increase of long-lived (>10hr) and short-lived (1-2hr) events. On the other hand, a relatively decrease of medium-lived events (3-10hr) are noticed in future climate scenario. The increase of extreme precipitation intensities in future climate is due to the increase in temperature under RCP4.5 (~2°C). Increase in temperature causes more evapotranspiration and subsequently increases the water vapor in the atmosphere.

  1. Expression responses of five cold tolerant related genes to two temperature dropping treatments in sea cucumber Apostichopus japonicus

    Science.gov (United States)

    Li, Chengze; Chang, Yaqing; Pang, Zhenguo; Ding, Jun; Ji, Nanjing

    2015-03-01

    Environmental conditions, including ambient temperature, play important roles in survival, growth development, and reproduction of the Japanese sea cucumber, Apostichopus japonicus. Low temperatures result in slowed growth and skin ulceration disease. In a previous study, we investigated the effect of low temperature on gene expression profiles in A. japonicus by suppression subtractive hybridization (SSH). Genes encoding Ferritin, Lysozyme, Hsp70, gp96, and AjToll were selected from a subtracted cDNA library of A. japonicus under acute cold stress. The transcriptional expression profiles of these genes were investigated in different tissues (coelomocyte, respiratory tree, intestine, longitudinal muscle) after exposure to acute and mild temperature dropping treatments. The results show that (1) the five cold-tolerance-related genes were found in all four tissues and the highest mRNA levels were observed in coelomocyte and respiratory tree; (2) under the temperature dropping treatments, three types of transcriptional regulation patterns were observed: primary suppression followed by up-regulation at -2°C, suppressed expression throughout the two treatments, and more rarely an initial stimulation followed by suppression; and (3) gene expression suppression was more severe under acute temperature dropping than under mild temperature dropping treatment. The five cold-tolerance-related genes that were distributed mainly in coelomocyte and respiratory tissues were generally down-regulated by low temperature stress but an inverse up-regulation event was found at the extreme temperature (-2°C).

  2. Electronic Components and Circuits for Extreme Temperature Environments

    Science.gov (United States)

    Patterson, Richard L.; Hammoud, Ahmad; Dickman, John E.; Gerber, Scott

    2003-01-01

    Planetary exploration missions and deep space probes require electrical power management and control systems that are capable of efficient and reliable operation in very low temperature environments. Presently, spacecraft operating in the cold environment of deep space carry a large number of radioisotope heating units in order to maintain the surrounding temperature of the on-board electronics at approximately 20 C. Electronics capable of operation at cryogenic temperatures will not only tolerate the hostile environment of deep space but also reduce system size and weight by eliminating or reducing the radioisotope heating units and their associate structures; thereby reducing system development as well as launch costs. In addition, power electronic circuits designed for operation at low temperatures are expected to result in more efficient systems than those at room temperature. This improvement results from better behavior and tolerance in the electrical and thermal properties of semiconductor and dielectric materials at low temperatures. The Low Temperature Electronics Program at the NASA Glenn Research Center focuses on research and development of electrical components, circuits, and systems suitable for applications in the aerospace environment and deep space exploration missions. Research is being conducted on devices and systems for reliable use down to cryogenic temperatures. Some of the commercial-off-the-shelf as well as developed components that are being characterized include switching devices, resistors, magnetics, and capacitors. Semiconductor devices and integrated circuits including digital-to-analog and analog-to-digital converters, DC/DC converters, operational amplifiers, and oscillators are also being investigated for potential use in low temperature applications. An overview of the NASA Glenn Research Center Low Temperature Electronic Program will be presented in this paper. A description of the low temperature test facilities along with

  3. Actual and future trends of extreme values of temperature for the NW Iberian Peninsula

    Science.gov (United States)

    Taboada, J.; Brands, S.; Lorenzo, N.

    2009-09-01

    It is now very well established that yearly averaged temperatures are increasing due to anthropogenic climate change. In the area of Galicia (NW Spain) this trend has also been determined. The main objective of this work is to assess actual and future trends of different extreme indices of temperature, which are of curcial importance for many impact studies. Station data for the study was provided by the CLIMA database of the regional government of Galicia (NW Spain). As direct GCM-output significantly underestimates the variance of daily surface temperature variables in NW Spain, these variables are obtained by applying a statistical downscaling technique (analog method), using 850hPa temperature and mean sea level pressure as combined predictors. The predictor fields have been extracted from three GCMs participating in the IPCC AR4 under A1, A1B and A2 scenarios. The definitions of the extreme indices have been taken from the joint CCl/CLIVAR/JCOMM Expert Team (ET) on Climate Change Detection and Indices (ETCCDI) This group has defined a set of standard extreme values to simplify intercomparisons of data from different regions of the world. For the temperatures in the period 1960-2006, results show a significant increase of the number of days with maximum temperatures above the 90th percentile. Furthermore, a significant decrease of the days with maximum temperatures below the 10th percentile has been found. The tendencies of minimum temperatures are reverse: less nights with minimum temperatures below 10th percentile, and more with minimum temperatures above 90th percentile. Those tendencies can be observed all over the year, but are more pronounced in summer. We have also calculated the relationship between the above mentioned extreme values and different teleconnection patterns appearing in the North Atlantic area. Results show that local tendencies are associated with trends of EA (Eastern Atlantic) and SCA (Scandinavian) patterns. NAO (North Atlantic

  4. Predicting temperature timit values for cold touchable surfaces

    NARCIS (Netherlands)

    Hartog, E.A. den

    2005-01-01

    During some occupational activities, workers have to handle objects or tools in cold environments. In other circumstances, contact between the hand and the cold surface might be accidental (e.g., when a worker touches a cold surface, a cooler, etc). In both cases, contact between the hands and the c

  5. Poorest countries experience earlier anthropogenic emergence of daily temperature extremes

    Science.gov (United States)

    Harrington, Luke J.; Frame, David J.; Fischer, Erich M.; Hawkins, Ed; Joshi, Manoj; Jones, Chris D.

    2016-05-01

    Understanding how the emergence of the anthropogenic warming signal from the noise of internal variability translates to changes in extreme event occurrence is of crucial societal importance. By utilising simulations of cumulative carbon dioxide (CO2) emissions and temperature changes from eleven earth system models, we demonstrate that the inherently lower internal variability found at tropical latitudes results in large increases in the frequency of extreme daily temperatures (exceedances of the 99.9th percentile derived from pre-industrial climate simulations) occurring much earlier than for mid-to-high latitude regions. Most of the world’s poorest people live at low latitudes, when considering 2010 GDP-PPP per capita; conversely the wealthiest population quintile disproportionately inhabit more variable mid-latitude climates. Consequently, the fraction of the global population in the lowest socio-economic quintile is exposed to substantially more frequent daily temperature extremes after much lower increases in both mean global warming and cumulative CO2 emissions.

  6. Effects of cold temperatures on the excitability of rat trigeminal ganglion neurons that are not for cold sensing.

    Science.gov (United States)

    Kanda, Hirosato; Gu, Jianguo G

    2017-05-01

    Aside from a small population of primary afferent neurons for sensing cold, which generate sensations of innocuous and noxious cold, it is generally believed that cold temperatures suppress the excitability of primary afferent neurons not responsible for cold sensing. These not-for-cold-sensing neurons include the majority of non-nociceptive and nociceptive afferent neurons. In this study we have found that the not-for-cold-sensing neurons of rat trigeminal ganglia (TG) change their excitability in several ways at cooling temperatures. In nearly 70% of not-for-cold-sensing TG neurons, a cooling temperature of 15°C increases their membrane excitability. We regard these neurons as cold-active neurons. For the remaining 30% of not-for-cold-sensing TG neurons, the cooling temperature of 15°C either has no effect (cold-ineffective neurons) or suppress their membrane excitability (cold-suppressive neurons). For cold-active neurons, the cold temperature of 15°C increases their excitability as is evidenced by increases in action potential (AP) firing numbers and/or the reduction in AP rheobase when these neurons are depolarized electrically. The cold temperature of 15°C significantly inhibits M-currents and increases membrane input resistance of cold-active neurons. Retigabine, an M-current activator, abolishes the effect of cold temperatures on AP firing, but not the effect of cold temperature on AP rheobase levels. The inhibition of M-currents and the increases of membrane input resistance are likely two mechanisms by which cooling temperatures increase the excitability of not-for-cold-sensing TG neurons. This article is part of the special article series "Pain". © 2015 International Society for Neurochemistry.

  7. Spectrophotometry of extreme helium stars - Ultraviolet fluxes and effective temperatures

    Science.gov (United States)

    Heber, U.; Drilling, J. S.; Schoenberner, D.; Lynas-Gray, A. E.

    1984-01-01

    Ultraviolet flux distributions are presented for the extremely helium rich stars BD +10 deg 2179, HD 124448, LSS 3378, BD -9 deg 4395, LSE 78, HD 160641, LSIV -1 deg 2, BD 1 deg 3438, HD 168476, MV Sgr, LS IV-14 deg 109 (CD -35 deg 11760), LSII +33 deg 5 and BD +1 deg 4381 (LSIV +2 deg 13) obtained with the International Ultraviolet Explorer (IUE). Broadband photometry and a newly computed grid of line blanketed model atmospheres were used to determine accurate angular diameters and total stellar fluxes. The resultant effective temperatures are in most cases in satisfactory agreement with those based on broadband photometry and/or high resolution spectroscopy in the visible. For two objects, LSII +33 deg 5 and LSE 78, disagreement was found between the IUE observations and broadband photometry: the colors predict temperatures around 20,000 K, whereas the UV spectra indicate much lower photospheric temperatures of 14,000 to 15,000 K. The new temperature scale for extreme helium stars extends to lower effective temperatures than that of Heber and Schoenberner (1981) and covers the range from 8,500 K to 32,000 K. Previously announced in STAR as N83-24433

  8. Reanalysis Data Evaluation to Study Temperature Extremes in Siberia

    Science.gov (United States)

    Shulgina, T. M.; Gordov, E. P.

    2014-12-01

    Ongoing global climate changes are strongly pronounced in Siberia by significant warming in the 2nd half of 20th century and recent extreme events such as 2010 heat wave and 2013 flood in Russia's Far East. To improve our understanding of observed climate extremes and to provide to regional decision makers the reliable scientifically based information with high special and temporal resolution on climate state, we need to operate with accurate meteorological data in our study. However, from available 231 stations across Siberia only 130 of them present the homogeneous daily temperature time series. Sparse, station network, especially in high latitudes, force us to use simulated reanalysis data. However those might differ from observations. To obtain reliable information on temperature extreme "hot spots" in Siberia we have compared daily temperatures form ERA-40, ERA Interim, JRA-25, JRA-55, NCEP/DOE, MERRA Reanalysis, HadEX2 and GHCNDEX gridded datasets with observations from RIHMI-WDC/CDIAC dataset for overlap period 1981-2000. Data agreement was estimated at station coordinates to which reanalysis data were interpolated using modified Shepard method. Comparison of averaged over 20 year annual mean temperatures shows general agreement for Siberia excepting Baikal region, where reanalyses significantly underestimate observed temperature behavior. The annual temperatures closest to observed one were obtained from ERA-40 and ERA Interim. Furthermore, t-test results show homogeneity of these datasets, which allows one to combine them for long term time series analysis. In particular, we compared the combined data with observations for percentile-based extreme indices. In Western Siberia reanalysis and gridded data accurately reproduce observed daily max/min temperatures. For East Siberia, Lake Baikal area, ERA Interim data slightly underestimates TN90p and TX90p values. Results obtained allows regional decision-makers to get required high spatial resolution (0,25°×0

  9. Murder or not? Cold temperature makes criminals appear to be cold-blooded and warm temperature to be hot-headed

    National Research Council Canada - National Science Library

    Gockel, Christine; Kolb, Peter M; Werth, Lioba

    2014-01-01

    .... Building on recent research about the close interplay between physical and interpersonal coldness and warmth, we examined in a lab experiment how ambient temperature within a comfort zone influences...

  10. Increased Stream Temperature in Response to Extreme Precipitation Events

    Science.gov (United States)

    Wilson, C. E.; Gooseff, M. N.

    2016-12-01

    Aquatic ecosystem temperature regulation is essential to the survival of riverine fish species restricted to limited water temperature ranges. Dissolved oxygen levels, similarly necessary to fish health, are decreased by rising temperatures, as warmer waters can hold less oxygen than colder waters. Climate change projections forecast increased precipitation intensities, a trend that has already been observed in the past decade. Though extreme events are becoming more common, the stream temperature response to high-intensity rainfall is not yet completely understood. Precipitation and stream temperature records from gages in the Upper Midwestern United States were analyzed to determine whether there exists a positive relationship between high-intensity rainfall and stream temperature response. This region was chosen for its already observed trends in increasing precipitation intensity, and rural gages were used in order to minimize the effect of impervious surfaces on runoff amounts and temperature. Days with recorded precipitation were divided by an intensity threshold and classified as either high-intensity or low-intensity days. While the effects of rain events on temperature are variable, increases in stream temperature in response to high-intensity rainfall were observed. For some basins, daily maximum rates of stream temperature increase were, on average, greater for higher intensity events. Similarly, the average daily stream temperature range was higher in streams on days of high-intensity precipitation, compared to days of low-intensity events. Understanding the effect of increasing precipitation intensity in conjunction with rising air temperatures will provide insight into the future of aquatic ecosystems and their adaptation to climate change.

  11. Dynamically-downscaled projections of changes in temperature extremes over China

    Science.gov (United States)

    Guo, Junhong; Huang, Guohe; Wang, Xiuquan; Li, Yongping; Lin, Qianguo

    2017-06-01

    In this study, likely changes in extreme temperatures (including 16 indices) over China in response to global warming throughout the twenty-first century are investigated through the PRECIS regional climate modeling system. The PRECIS experiment is conducted at a spatial resolution of 25 km and is driven by a perturbed-physics ensemble to reflect spatial variations and model uncertainties. Simulations of present climate (1961-1990) are compared with observations to validate the model performance in reproducing historical climate over China. Results indicate that the PRECIS demonstrates reasonable skills in reproducing the spatial patterns of observed extreme temperatures over the most regions of China, especially in the east. Nevertheless, the PRECIS shows a relatively poor performance in simulating the spatial patterns of extreme temperatures in the western mountainous regions, where its driving GCM exhibits more uncertainties due to lack of insufficient observations and results in more errors in climate downscaling. Future spatio-temporal changes of extreme temperature indices are then analyzed for three successive periods (i.e., 2020s, 2050s and 2080s). The projected changes in extreme temperatures by PRECIS are well consistent with the results of the major global climate models in both spatial and temporal patterns. Furthermore, the PRECIS demonstrates a distinct superiority in providing more detailed spatial information of extreme indices. In general, all extreme indices show similar changes in spatial pattern: large changes are projected in the north while small changes are projected in the south. In contrast, the temporal patterns for all indices vary differently over future periods: the warm indices, such as SU, TR, WSDI, TX90p, TN90p and GSL are likely to increase, while the cold indices, such as ID, FD, CSDI, TX10p and TN10p, are likely to decrease with time in response to global warming. Nevertheless, the magnitudes of changes in all indices tend to

  12. Characterization and effects of cold fronts in the Colombian Caribbean Coast and their relationship to extreme wave events

    Directory of Open Access Journals (Sweden)

    J. C. Ortiz-Royero

    2013-07-01

    passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that, there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of structures in this region of the Caribbean.

  13. Differential Effects of Temperature Extremes on Hospital Admission Rates for Respiratory Disease between Indigenous and Non-Indigenous Australians in the Northern Territory.

    Science.gov (United States)

    Green, Donna; Bambrick, Hilary; Tait, Peter; Goldie, James; Schultz, Rosalie; Webb, Leanne; Alexander, Lisa; Pitman, Andrew

    2015-12-03

    The health gap between Indigenous and non-Indigenous Australians may be exacerbated by climate change if temperature extremes have disproportionate adverse effects on Indigenous people. To explore this issue, we analysed the effect of temperature extremes on hospital admissions for respiratory diseases, stratified by age, Indigenous status and sex, for people living in two different climates zones in the Northern Territory during the period 1993-2011. We examined admissions for both acute and chronic respiratory diagnoses, controlling for day of the week and seasonality variables. Our analysis showed that: (1) overall, Indigenous hospital admission rates far exceeded non-Indigenous admission rates for acute and chronic diagnoses, and Top End climate zone admission rates exceeded Central Australia climate zone admission rates; (2) extreme cold and hot temperatures were associated with inconsistent changes in admission rates for acute respiratory disease in Indigenous and non-Indigenous children and older adults; and (3) no response to cold or hot temperature extremes was found for chronic respiratory diagnoses. These findings support our two hypotheses, that extreme hot and cold temperatures have a different effect on hospitalisations for respiratory disease between Indigenous and non-Indigenous people, and that these health risks vary between the different climate zones. We did not, however, find that there were differing responses to temperature extremes in the two populations, suggesting that any increased vulnerability to climate change in the Indigenous population of the Northern Territory arises from an increased underlying risk to respiratory disease and an already greater existing health burden.

  14. Transport Coefficients at Zero Temperature from Extremal Black Holes

    CERN Document Server

    Edalati, Mohammad; Leigh, Robert G

    2009-01-01

    Using the AdS/CFT correspondence we study transport coefficients of a strongly-coupled (2 +1)-dimensional boundary field theory at zero temperature and finite charge density. The boundary field theory under consideration is dual to the extremal Reissner-Nordstrom AdS(4) black hole in the bulk. We show that, like the cases of scalar and spinor operators studied in arXiv:0907.2694 [hep-th], the correlators of charge (vector) current and energy-momentum (tensor) operators exhibit scaling behavior at low frequency. The existence of such low frequency behavior is related to the fact that the near-horizon geometry of the extremal black hole background has an AdS(2) factor. We carefully calculate the shear viscosity (at zero temperature) and show that the ratio of the shear viscosity to the entropy density takes the value of 1/4\\pi. Because of the AdS(2) factor, we argue that this result stays the same for all d-dimensional boundary field theories dual to the extremal Reissner-Nordstrom AdS(d+1) black holes. Also, w...

  15. Synthesis and microdiffraction at extreme pressures and temperatures.

    Science.gov (United States)

    Lavina, Barbara; Dera, Przemyslaw; Meng, Yue

    2013-10-07

    High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 (1) will be shown.

  16. Perception, Action, and Cognition of Football Referees in Extreme Temperatures: Impact on Decision Performance

    Directory of Open Access Journals (Sweden)

    Nadia Gaoua

    2017-08-01

    Full Text Available Different professional domains require high levels of physical performance alongside fast and accurate decision-making. Construction workers, police officers, firefighters, elite sports men and women, the military and emergency medical professionals are often exposed to hostile environments with limited options for behavioral coping strategies. In this (mini review we use football refereeing as an example to discuss the combined effect of intense physical activity and extreme temperatures on decision-making and suggest an explicative model. In professional football competitions can be played in temperatures ranging from -5°C in Norway to 30°C in Spain for example. Despite these conditions, the referee’s responsibility is to consistently apply the laws fairly and uniformly, and to ensure the rules are followed without waning or adversely influencing the competitiveness of the play. However, strenuous exercise in extreme environments imposes increased physiological and psychological stress that can affect decision-making. Therefore, the physical exertion required to follow the game and the thermal strain from the extreme temperatures may hinder the ability of referees to make fast and accurate decisions. Here, we review literature on the physical and cognitive requirements of football refereeing and how extreme temperatures may affect referees’ decisions. Research suggests that both hot and cold environments have a negative impact on decision-making but data specific to decision-making is still lacking. A theoretical model of decision-making under the constraint of intense physical activity and thermal stress is suggested. Future naturalistic studies are needed to validate this model and provide clear recommendations for mitigating strategies.

  17. Perception, Action, and Cognition of Football Referees in Extreme Temperatures: Impact on Decision Performance.

    Science.gov (United States)

    Gaoua, Nadia; de Oliveira, Rita F; Hunter, Steve

    2017-01-01

    Different professional domains require high levels of physical performance alongside fast and accurate decision-making. Construction workers, police officers, firefighters, elite sports men and women, the military and emergency medical professionals are often exposed to hostile environments with limited options for behavioral coping strategies. In this (mini) review we use football refereeing as an example to discuss the combined effect of intense physical activity and extreme temperatures on decision-making and suggest an explicative model. In professional football competitions can be played in temperatures ranging from -5°C in Norway to 30°C in Spain for example. Despite these conditions, the referee's responsibility is to consistently apply the laws fairly and uniformly, and to ensure the rules are followed without waning or adversely influencing the competitiveness of the play. However, strenuous exercise in extreme environments imposes increased physiological and psychological stress that can affect decision-making. Therefore, the physical exertion required to follow the game and the thermal strain from the extreme temperatures may hinder the ability of referees to make fast and accurate decisions. Here, we review literature on the physical and cognitive requirements of football refereeing and how extreme temperatures may affect referees' decisions. Research suggests that both hot and cold environments have a negative impact on decision-making but data specific to decision-making is still lacking. A theoretical model of decision-making under the constraint of intense physical activity and thermal stress is suggested. Future naturalistic studies are needed to validate this model and provide clear recommendations for mitigating strategies.

  18. Risky Adaptation: The Effect of Temperature Extremes on HIV Prevalence

    Science.gov (United States)

    Baker, R.

    2016-12-01

    Previous work has linked rainfall shock to an increase in HIV prevalence in Sub-Saharan Africa. In this paper we take advantage of repeated waves of the Demographic and Health Survey (DHS) and a new high resolution climate dataset for the African continent to test the non-linear relationship between temperature and HIV. We find a strong and significant relationship between recent high temperatures and increases in HIV prevalence in a region. We then test the effect of temperature on risk factors that may contribute to this increase. High temperatures are linked to an increase in sexual violence, number of partners and a decrease in condom usage - all of which may contribute to the uptake in HIV rate. This paper contributes to the literature on adaptation from two standpoints. First, we suggest that some behavioral changes that are classed as adaptations, in the sense that they allow for consumption smoothing in the face of extreme temperatures, may carry unexpected risks to the individuals involved. Second, we find preliminary evidence that the relationship between temperature and these risky behaviors is diminished in regions prone to higher temperatures, suggesting some adaptation is possible in the long run.

  19. Fast temperature spectrometer for samples under extreme conditions.

    Science.gov (United States)

    Zhang, Dongzhou; Jackson, Jennifer M; Zhao, Jiyong; Sturhahn, Wolfgang; Alp, E Ercan; Toellner, Thomas S; Hu, Michael Y

    2015-01-01

    We have developed a multi-wavelength Fast Temperature Readout (FasTeR) spectrometer to capture a sample's transient temperature fluctuations, and reduce uncertainties in melting temperature determination. Without sacrificing accuracy, FasTeR features a fast readout rate (about 100 Hz), high sensitivity, large dynamic range, and a well-constrained focus. Complimenting a charge-coupled device spectrometer, FasTeR consists of an array of photomultiplier tubes and optical dichroic filters. The temperatures determined by FasTeR outside of the vicinity of melting are, generally, in good agreement with results from the charge-coupled device spectrometer. Near melting, FasTeR is capable of capturing transient temperature fluctuations, at least on the order of 300 K/s. A software tool, SIMFaster, is described and has been developed to simulate FasTeR and assess design configurations. FasTeR is especially suitable for temperature determinations that utilize ultra-fast techniques under extreme conditions. Working in parallel with the laser-heated diamond-anvil cell, synchrotron Mössbauer spectroscopy, and X-ray diffraction, we have applied the FasTeR spectrometer to measure the melting temperature of (57)Fe0.9Ni0.1 at high pressure.

  20. Recent changes in Georgia׳s temperature means and extremes: Annual and seasonal trends between 1961 and 2010

    Directory of Open Access Journals (Sweden)

    I. Keggenhoff

    2015-06-01

    Full Text Available Sixteen temperature minimum and maximum series are used to quantify annual and seasonal changes in temperature means and extremes over Georgia (Southern Caucasus during the period 1961 and 2010. Along with trends in mean minimum and maximum temperature, eight indices are selected from the list of climate extreme indices as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI of the Commission for Climatology of the World Meteorological Organization (WMO, for studying trends in temperature extremes. Between the analysis periods 1961–2010, 1971–2010 and 1981–2010 pronounced warming trends are determined for all Georgia-averaged trends in temperature means and extremes, while all magnitudes of trends increase towards the most recent period. During 1981 and 2010, significant warming trends for annual minimum and maximum temperature at a rate of 0.39 °C (0.47 °C days/decade and particularly for the warm temperature extremes, summer days, warm days and nights and the warm spell duration index are evident, whereas warm extremes show larger trends than cold extremes. The most pronounced trends are determined for summer days 6.2 days/decade, while the warm spell duration index indicates an increase in the occurrence of warm spells by 5.4 days/decade during 1981 and 2010. In the comparison of seasonal changes in temperature means and extremes, the largest magnitudes of warming trends can be observed for temperature maximum in summer and temperature minimum in fall. Between 1981 and 2010, summer maximum temperature shows a significant warming at a rate of 0.84 °C/decade, increasing almost twice as fast as its annual trend (0.47 °C/decade. The Georgia-averaged trends for temperature minimum in fall increase by 0.59 °C/decade. Strongest significant trends in temperature extremes are identified during 1981 and 2010 for warm nights (4.6 days/decade in summer and fall as well as for warm days (5.6 days/decade in summer

  1. Trends in indices of daily temperature and precipitations extremes in Morocco

    Science.gov (United States)

    Filahi, S.; Tanarhte, M.; Mouhir, L.; El Morhit, M.; Tramblay, Y.

    2016-05-01

    The purpose of this paper is to provide a summary of Morocco's climate extreme trends during the last four decades. Indices were computed based on a daily temperature and precipitation using a consistent approach recommended by the ETCCDI. Trends in these indices were calculated at 20 stations from 1970 to 2012. Twelve indices were considered to detect trends in temperature. A large number of stations have significant trends and confirm an increase in temperature, showing increased warming during spring and summer seasons. The results also show a decrease in the number of cold days and nights and an increase in the number of warm days and nights. Increasing trends have also been found in the absolute warmest and coldest temperatures of the year. A clear increase is detected for warm nights and diurnal temperature range. Eight indices for precipitation were also analyzed, but the trends for these precipitation indices are much less significant than for temperature indices and show more mixed spatial patterns of change. Heavy precipitation events do not exhibit significant trends except at a few locations, in the north and central parts of Morocco, with a general tendency towards drier conditions. The correlation between these climate indices and the large-scale atmospheric circulations indices such as the NAO, MO, and WEMO were also analyzed. Results show a stronger relationship with these climatic indices for the precipitation indices compared to the temperature indices. The correlations are more significant in the Atlantic regions, but they remain moderate at the whole country scale.

  2. Changes in extreme temperature and precipitation events in the Loess Plateau (China) during 1960-2013 under global warming

    Science.gov (United States)

    Sun, Wenyi; Mu, Xingmin; Song, Xiaoyan; Wu, Dan; Cheng, Aifang; Qiu, Bing

    2016-02-01

    In recent decades, extreme climatic events have been a major issue worldwide. Regional assessments on various climates and geographic regions are needed for understanding uncertainties in extreme events' responses to global warming. The objective of this study was to assess the annual and decadal trends in 12 extreme temperature and 10 extreme precipitation indices in terms of intensity, frequency, and duration over the Loess Plateau during 1960-2013. The results indicated that the regionally averaged trends in temperature extremes were consistent with global warming. The occurrence of warm extremes, including summer days (SU), tropical nights (TR), warm days (TX90), and nights (TN90) and a warm spell duration indicator (WSDI), increased by 2.76 (P spell duration indicator (CSDI) exhibited decreases of - 3.22 (P wet-day and extremely wet-day precipitation were not significant. Large-scale atmospheric circulation indices, such as the Western Pacific Subtropical High Intensity Index (WPSHII) and Arctic Oscillation (AO), strongly influences warm/cold extremes and contributes significantly to climate changes in the Loess Plateau. The enhanced geopotential height over the Eurasian continent and increase in water vapor divergence in the rainy season have contributed to the changes of the rapid warming and consecutive drying in the Loess Plateau.

  3. Simulation of extreme temperature over Odisha during May 2015

    Directory of Open Access Journals (Sweden)

    K.C. Gouda

    2017-09-01

    Full Text Available An extreme temperature event (heat wave over the state of Odisha was unique as it lasted for about 2 weeks in the 3rd and 4th weeks of May 2015. There was a similar severe heat wave in western and central Odisha in the month of April 1998. The interesting feature of the recent episodic heat wave is that it prevailed in the late pre-monsoon season with wider spread in the state of Odisha. Around 12–15 cities experienced a daily maximum temperature of over 45 °C during the strong heat wave period, and 25th −27th May was declared as the red box zone. In this study, we first analysed the intense summer temperature of 2015 May using India Meteorological Department observations of daily maximum temperature. The observed heat wave phenomenon was then simulated using the Weather Research and Forecast Model (WRFV3 at 2-km horizontal resolution to assess its ability to forecast such a rare event. The observational analysis clearly indicated that this episodic event was unique both in terms of intensity, geographical spread and duration. An optimized configuration of the WRF model is proposed and implemented for the simulation of the episodic heat wave phenomenon (daily maximum temperature over the state of Odisha. The time-ensemble simulation of the temperature is shown to be in close agreement with the station-scale observations.

  4. Mild cold effects on hunger, food intake, satiety and skin temperature in humans

    Directory of Open Access Journals (Sweden)

    M Langeveld

    2016-04-01

    Full Text Available Background Mild cold exposure increases energy expenditure and can influence energy balance, but at the same time it does not increase appetite and energy intake. Objective To quantify dermal insulative cold response, we assessed thermal comfort and skin temperatures changes by infrared thermography. Methods We exposed healthy volunteers to either a single episode of environmental mild cold or thermoneutrality. We measured hunger sensation and actual free food intake. After a thermoneutral overnight stay, five males and five females were exposed to either 18°C (mild cold or 24°C (thermoneutrality for 2.5 h. Metabolic rate, vital signs, skin temperature, blood biochemistry, cold and hunger scores were measured at baseline and for every 30 min during the temperature intervention. This was followed by an ad libitum meal to obtain the actual desired energy intake after cold exposure. Results We could replicate the cold-induced increase in REE. But no differences were detected in hunger, food intake, or satiety after mild cold exposure compared with thermoneutrality. After long-term cold exposure, high cold sensation scores were reported, which were negatively correlated with thermogenesis. Skin temperature in the sternal area was tightly correlated with the increase in energy expenditure. Conclusions It is concluded that short-term mild cold exposure increases energy expenditure without changes in food intake. Mild cold exposure resulted in significant thermal discomfort, which was negatively correlated with the increase in energy expenditure. Moreover, there is a great between-subject variability in cold response. These data provide further insights on cold exposure as an anti-obesity measure.

  5. Mild cold effects on hunger, food intake, satiety and skin temperature in humans.

    Science.gov (United States)

    Langeveld, M; Tan, C Y; Soeters, M R; Virtue, S; Ambler, G K; Watson, L P E; Murgatroyd, P R; Chatterjee, V K; Vidal-Puig, A

    2016-03-01

    Mild cold exposure increases energy expenditure and can influence energy balance, but at the same time it does not increase appetite and energy intake. To quantify dermal insulative cold response, we assessed thermal comfort and skin temperatures changes by infrared thermography. We exposed healthy volunteers to either a single episode of environmental mild cold or thermoneutrality. We measured hunger sensation and actual free food intake. After a thermoneutral overnight stay, five males and five females were exposed to either 18°C (mild cold) or 24°C (thermoneutrality) for 2.5 h. Metabolic rate, vital signs, skin temperature, blood biochemistry, cold and hunger scores were measured at baseline and for every 30 min during the temperature intervention. This was followed by an ad libitum meal to obtain the actual desired energy intake after cold exposure. We could replicate the cold-induced increase in REE. But no differences were detected in hunger, food intake, or satiety after mild cold exposure compared with thermoneutrality. After long-term cold exposure, high cold sensation scores were reported, which were negatively correlated with thermogenesis. Skin temperature in the sternal area was tightly correlated with the increase in energy expenditure. It is concluded that short-term mild cold exposure increases energy expenditure without changes in food intake. Mild cold exposure resulted in significant thermal discomfort, which was negatively correlated with the increase in energy expenditure. Moreover, there is a great between-subject variability in cold response. These data provide further insights on cold exposure as an anti-obesity measure. © 2016 The authors.

  6. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is

  7. Trainability of cold induced vasodilation

    NARCIS (Netherlands)

    Daanen, H.A.M.; Raymann, R.J.E.M.; Stoop, M.

    2007-01-01

    Peripheral cold injuries are often reported in mountaineers. Not only low ambient temperatures, but also the hypobaric circumstances are known to be major environmental risk factors. When the fingers are exposed to extreme cold for several minutes, cold induced vasodilation (CIVD) occurs, that is re

  8. Effects of photoperiod, growth temperature and cold acclimatisation on glucosinolates, sugars and fatty acids in kale.

    Science.gov (United States)

    Steindal, Anne Linn Hykkerud; Rødven, Rolf; Hansen, Espen; Mølmann, Jørgen

    2015-05-01

    Curly kale is a robust, cold tolerant plant with a high content of health-promoting compounds, grown at a range of latitudes. To assess the effects of temperature, photoperiod and cold acclimatisation on levels of glucosinolates, fatty acids and soluble sugars in kale, an experiment was set up under controlled conditions. Treatments consisted of combinations of the temperatures 15/9 or 21/15 °C, and photoperiods of 12 or 24h, followed by a cold acclimatisation period. Levels of glucosinolates and fatty acid types in leaves were affected by growth conditions and cold acclimatisation, being generally highest before acclimatisation. The effects of growth temperature and photoperiod on freezing tolerance were most pronounced in plants grown without cold acclimatisation. The results indicate that cold acclimatisation can increase the content of soluble sugar and can thereby improve the taste, whilst the content of unsaturated fatty and glucosinolates acids may decrease.

  9. Evaluation of large-scale meteorological patterns associated with temperature extremes in the NARCCAP regional climate model simulations

    Science.gov (United States)

    Loikith, Paul C.; Waliser, Duane E.; Lee, Huikyo; Neelin, J. David; Lintner, Benjamin R.; McGinnis, Seth; Mearns, Linda O.; Kim, Jinwon

    2015-12-01

    Large-scale meteorological patterns (LSMPs) associated with temperature extremes are evaluated in a suite of regional climate model (RCM) simulations contributing to the North American Regional Climate Change Assessment Program. LSMPs are characterized through composites of surface air temperature, sea level pressure, and 500 hPa geopotential height anomalies concurrent with extreme temperature days. Six of the seventeen RCM simulations are driven by boundary conditions from reanalysis while the other eleven are driven by one of four global climate models (GCMs). Four illustrative case studies are analyzed in detail. Model fidelity in LSMP spatial representation is high for cold winter extremes near Chicago. Winter warm extremes are captured by most RCMs in northern California, with some notable exceptions. Model fidelity is lower for cool summer days near Houston and extreme summer heat events in the Ohio Valley. Physical interpretation of these patterns and identification of well-simulated cases, such as for Chicago, boosts confidence in the ability of these models to simulate days in the tails of the temperature distribution. Results appear consistent with the expectation that the ability of an RCM to reproduce a realistically shaped frequency distribution for temperature, especially at the tails, is related to its fidelity in simulating LMSPs. Each ensemble member is ranked for its ability to reproduce LSMPs associated with observed warm and cold extremes, identifying systematically high performing RCMs and the GCMs that provide superior boundary forcing. The methodology developed here provides a framework for identifying regions where further process-based evaluation would improve the understanding of simulation error and help guide future model improvement and downscaling efforts.

  10. Observed Trends in Indices of Daily Precipitation and Temperature Extremes in Rio de Janeiro State (brazil)

    Science.gov (United States)

    Silva, W. L.; Dereczynski, C. P.; Cavalcanti, I. F.

    2013-05-01

    One of the main concerns of contemporary society regarding prevailing climate change is related to possible changes in the frequency and intensity of extreme events. Strong heat and cold waves, droughts, severe floods, and other climatic extremes have been of great interest to researchers because of its huge impact on the environment and population, causing high monetary damages and, in some cases, loss of life. The frequency and intensity of extreme events associated with precipitation and air temperature have been increased in several regions of the planet in recent years. These changes produce serious impacts on human activities such as agriculture, health, urban planning and development and management of water resources. In this paper, we analyze the trends in indices of climatic extremes related to daily precipitation and maximum and minimum temperatures at 22 meteorological stations of the National Institute of Meteorology (INMET) in Rio de Janeiro State (Brazil) in the last 50 years. The present trends are evaluated using the software RClimdex (Canadian Meteorological Service) and are also subjected to statistical tests. Preliminary results indicate that periods of drought are getting longer in Rio de Janeiro State, except in the North/Northwest area. In "Vale do Paraíba", "Região Serrana" and "Região dos Lagos" the increase of consecutive dry days is statistically significant. However, we also detected an increase in the total annual rainfall all over the State (taxes varying from +2 to +8 mm/year), which are statistically significant at "Região Serrana". Moreover, the intensity of heavy rainfall is also growing in most of Rio de Janeiro, except in "Costa Verde". The trends of heavy rainfall indices show significant increase in the "Metropolitan Region" and in "Região Serrana", factor that increases the vulnerability to natural disasters in these areas. With respect to temperature, it is found that the frequency of hot (cold) days and nights is

  11. Climate change and the impact of extreme temperatures on aviation

    Science.gov (United States)

    Coffel, E.; Horton, R.

    2014-12-01

    Weather is the most significant factor affecting aircraft operations, accounting for 70-80% of passenger delays and costing airlines hundreds of millions of dollars per year in lost revenue. Temperature and airport elevation significantly influence the maximum allowable takeoff weight of an aircraft by changing the surface air density and thus the lift produced at a given speed. For a given runway length, airport elevation, and aircraft type there is a temperature threshold above which the airplane cannot take off at its maximum weight and thus must be weight restricted. The number of summer days necessitating weight restriction has increased since 1980 along with the observed increase in surface temperature. Climate change is projected to increase mean temperatures at all airports and significantly increase the frequency and severity of extreme heat events at some. These changes will negatively affect aircraft performance, leading to increased weight restrictions especially at airports with short runways and little room to expand. For a Boeing 737-800 aircraft, we find that the number of weight restriction days between May and September will increase by 50-100% at four major airports in the United States by 2050-2070 under the RCP8.5 high emissions scenario. These performance reductions may have a significant economic effect on the airline industry, leading to lower profits and higher passenger fares. Increased weight restrictions have previously been identified as potential impacts of climate change, but this study is the first to quantify the effect of higher temperatures on commercial aviation.

  12. On extreme rainfall intensity increases with air temperature

    Science.gov (United States)

    Molnar, Peter; Fatichi, Simone; Paschalis, Athanasios; Gaal, Ladislav; Szolgay, Jan; Burlando, Paolo

    2016-04-01

    The water vapour holding capacity of air increases at about 7% per degree C according to the Clausius-Clapeyron (CC) relation. This is one of the arguments why a warmer future atmosphere, being able to hold more moisture, will generate higher extreme precipitation intensities. However, several empirical studies have recently demonstrated an increase in extreme rain intensities with air temperature above CC rates, in the range 7-14% per degree C worldwide (called super-CC rates). This was observed especially for shorter duration rainfall, i.e. in hourly and finer resolution data (e.g. review in Westra et al., 2014). The super-CC rate was attributed to positive feedbacks between water vapour and the updraft dynamics in convective clouds and lateral supply (convergence) of moisture. In addition, mixing of storm types was shown to be potentially responsible for super-CC rates in empirical studies. Assuming that convective events are accompanied by lightning, we will show on a large rainfall dataset in Switzerland (30 year records of 10-min and 1-hr data from 59 stations) that while the average rate of increase in extreme rainfall intensity (95th percentile) is 6-7% in no-lightning events and 8-9% in lightning events, it is 11-13% per degree C when all events are combined (Molnar et al., 2015). These results are relevant for climate change studies which predict shifts in storm types in a warmer climate in some parts of the world. The observation that extreme rain intensity and air temperature are positively correlated has consequences for the stochastic modelling of rainfall. Most current stochastic models do not explicitly include a direct rain intensity-air temperature dependency beyond applying factors of change predicted by climate models to basic statistics of precipitation. Including this dependency explicitly in stochastic models will allow, for example in the nested modelling approach of Paschalis et al. (2014), the random cascade disaggregation routine to be

  13. Storms or cold fronts: what is really responsible for the extreme waves regime in the Colombian Caribbean coastal region?

    Science.gov (United States)

    Otero, L. J.; Ortiz-Royero, J. C.; Ruiz-Merchan, J. K.; Higgins, A. E.; Henriquez, S. A.

    2016-02-01

    The aim of this study is to determine the contribution and importance of cold fronts and storms to extreme waves in different areas of the Colombian Caribbean in an attempt to determine the extent of the threat posed by the flood processes to which these coastal populations are exposed. Furthermore, the study wishes to establish the actions to which coastal engineering constructions should be subject. In the calculation of maritime constructions, the most important parameter is the height of the wave. For this reason, it is necessary to establish the design wave height to which a coastal engineering structure should be resistant. This wave height varies according to the return period considered. The significant height values for the areas focused on in the study were calculated in accordance with Gumbel's extreme value methodology. The methodology was evaluated using data from the reanalysis of the spectral National Oceanic and Atmospheric Administration (NOAA) WAVEWATCH III® (WW3) model for 15 points along the 1600 km of the Colombian Caribbean coastline (continental and insular) between the years 1979 and 2009. The results demonstrated that the extreme waves caused by tropical cyclones and those caused by cold fronts have different effects along the Colombian Caribbean coast. Storms and hurricanes are of greater importance in the Guajira Peninsula (Alta Guajira). In the central area (consisting of Baja Guajira, and the cities of Santa Marta, Barranquilla, and Cartagena), the strong impact of cold fronts on extreme waves is evident. However, in the southern region of the Colombian Caribbean coast (ranging from the Gulf of Morrosquillo to the Gulf of Urabá), the extreme values of wave heights are lower than in the previously mentioned regions, despite being dominated mainly by the passage of cold fronts. Extreme waves in the San Andrés and Providencia insular region present a different dynamic from that in the continental area due to their geographic location

  14. Extreme warm temperatures alter forest phenology and productivity in Europe.

    Science.gov (United States)

    Crabbe, Richard A; Dash, Jadu; Rodriguez-Galiano, Victor F; Janous, Dalibor; Pavelka, Marian; Marek, Michal V

    2016-09-01

    Recent climate warming has shifted the timing of spring and autumn vegetation phenological events in the temperate and boreal forest ecosystems of Europe. In many areas spring phenological events start earlier and autumn events switch between earlier and later onset. Consequently, the length of growing season in mid and high latitudes of European forest is extended. However, the lagged effects (i.e. the impact of a warm spring or autumn on the subsequent phenological events) on vegetation phenology and productivity are less explored. In this study, we have (1) characterised extreme warm spring and extreme warm autumn events in Europe during 2003-2011, and (2) investigated if direct impact on forest phenology and productivity due to a specific warm event translated to a lagged effect in subsequent phenological events. We found that warmer events in spring occurred extensively in high latitude Europe producing a significant earlier onset of greening (OG) in broadleaf deciduous forest (BLDF) and mixed forest (MF). However, this earlier OG did not show any significant lagged effects on autumnal senescence. Needleleaf evergreen forest (NLEF), BLDF and MF showed a significantly delayed end of senescence (EOS) as a result of extreme warm autumn events; and in the following year's spring phenological events, OG started significantly earlier. Extreme warm spring events directly led to significant (p=0.0189) increases in the productivity of BLDF. In order to have a complete understanding of ecosystems response to warm temperature during key phenological events, particularly autumn events, the lagged effect on the next growing season should be considered.

  15. Intestinal temperature does not reflect rectal temperature during prolonged, intense running with cold fluid ingestion.

    Science.gov (United States)

    Savoie, Félix A; Dion, Tommy; Asselin, Audrey; Gariepy, Carolanne; Boucher, Pierre M; Berrigan, Félix; Goulet, Eric D B

    2015-02-01

    It is generally assumed that intestinal temperature (Tint), as measured with a telemetric pill, agrees relatively well with rectal temperature (Trec) during exercise. However, whether Tint reflects Trec during prolonged, intense and continuous exercise when cold fluids are consumed is unknown. Therefore, we compared Trec and Tint during a half-marathon during which cold water was ingested to prevent bodyweight (BW) losses >2%. Nine endurance athletes (age 30  ±  5 years) underwent a 21.1 km running time-trial (TT) in the heat (~30 °C and 44% RH) while BW losses were maintained to ~1% with continuous cold (4 °C) water provision. Tint and Trec were monitored throughout the TT. Hypohydration level, TT time and fluid intake were 1.2  ±  0.4% BW, 93.2  ±  9.9 min and 2143  ±  264 ml, respectively. Trec was systematically higher than Tint by 0.25 °C (95% CI: 0.14-0.37 °C). Tint and Trec showed an excellent relative (r = 0.90, p < 0.01), but poor absolute agreement as reflected by a 95% limit of agreement of ±1.07 °C and a standard error of measurement of ±0.39 °C. In conclusion, Tint does not mirror Trec during prolonged, intense running with cold fluid ingestion and, therefore, these measures should not be used interchangeably under this scenario.

  16. Tendencies of extreme values on rainfall and temperature and its relationship with teleconnection patterns

    Science.gov (United States)

    Taboada, J. J.; Cabrejo, A.; Guarin, D.; Ramos, A. M.

    2009-04-01

    It is now very well established that yearly averaged temperatures are increasing due to anthropogenic climate change. In the area of Galicia (NW Spain) this trend has also been determined. Rainfall does not show a clear tendency in its yearly accumulated values. The aim of this work is to study different extreme indices of rainfall and temperatures analysing variability and possible trends associated to climate change. Station data for the study was provided by the CLIMA database of the regional government of Galicia (NW Spain). The definition of the extreme indices was taken from the joint CCl/CLIVAR/JCOMM Expert Team (ET) on Climate Change Detection and Indices (ETCCDI) This group has defined a set of standard extreme values to simplify intercomparison of data from different regions of the world. For the temperatures in the period 1960-2006, results show a significant increase of the number of days with maximum temperatures above the 90th percentile. Furthermore, a significant decrease of the days with maximum temperatures below the 10th percentile has been found. The tendencies of minimum temperatures are reverse: fewer nights with minimum temperatures below 10th percentile, and more with minimum temperatures above 90th percentile. Those tendencies can be observed all over the year, but are more pronounced in summer. This trend is expected to continue in the next decades because of anthropogenic climate change. We have also calculated the relationship between the above mentioned extreme values and different teleconnection patterns appearing in the North Atlantic area. Results show that local tendencies are associated with trends of EA (Eastern Atlantic) and SCA (Scandinavian) patterns. NAO (North Atlantic Oscillation) has also some relationship with these tendencies, but only related with cold days and nights in winter. Rainfall index do not show any clear tendency on the annual scale. Nevertheless, the count of days when precipitation is greater than 20mm (R20

  17. Cold-tolerant crop species have greater temperature homeostasis of leaf respiration and photosynthesis than cold-sensitive species.

    Science.gov (United States)

    Yamori, Wataru; Noguchi, Ko; Hikosaka, Kouki; Terashima, Ichiro

    2009-02-01

    Some plant species show constant rates of respiration and photosynthesis measured at their respective growth temperatures (temperature homeostasis), whereas others do not. However, it is unclear what species show such temperature homeostasis and what factors affect the temperature homeostasis. To analyze the inherent ability of plants to acclimate respiration and photosynthesis to different growth temperatures, we examined 11 herbace-ous crops with different cold tolerance. Leaf respiration (R(area)) and photosynthetic rate (P(area)) under high light at 360 microl l(-1) CO(2) concentrations were measured in plants grown at 15 and 30 degrees C. Cold-tolerant species showed a greater extent of temperature homeostasis of both R(area) and P(area) than cold-sensitive species. The underlying mechanisms which caused differences in the extent of temperature homeostasis were examined. The extent of temperature homeostasis of P(area) was not determined by differences in leaf mass and nitrogen content per leaf area, but by differences in photosynthetic nitrogen use efficiency (PNUE). Moreover, differences in PNUE were due to differences in the maximum catalytic rate of Rubisco, Rubisco contents and amounts of nitrogen invested in Rubisco. These findings indicated that the temperature homeostasis of photosynthesis was regulated by various parameters. On the other hand, the extent of temperature homeostasis of R(area) was unrelated to the maximum activity of the respiratory enzyme (NAD-malic enzyme). The R(area)/P(area) ratio was maintained irrespective of the growth temperatures in all the species, suggesting that the extent of temperature homeostasis of R(area) interacted with the photosynthetic rate and/or the homeostasis of photosynthesis.

  18. Comparing regional precipitation and temperature extremes in climate model and reanalysis products

    Directory of Open Access Journals (Sweden)

    Oliver Angélil

    2016-09-01

    Full Text Available A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.

  19. Comparing regional precipitation and temperature extremes in climate model and reanalysis products.

    Science.gov (United States)

    Angélil, Oliver; Perkins-Kirkpatrick, Sarah; Alexander, Lisa V; Stone, Dáithí; Donat, Markus G; Wehner, Michael; Shiogama, Hideo; Ciavarella, Andrew; Christidis, Nikolaos

    2016-09-01

    A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.

  20. Qualification of Fiber Optic Cables for Martian Extreme Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Lindensmith, Christian A.; Roberts, William T.; Rainen, Richard A.

    2011-01-01

    Means have been developed for enabling fiber optic cables of the Laser Induced Breakdown Spectrometer instrument to survive ground operations plus the nominal 670 Martian conditions that include Martian summer and winter seasons. The purpose of this development was to validate the use of the rover external fiber optic cabling of ChemCam for space applications under the extreme thermal environments to be encountered during the Mars Science Laboratory (MSL) mission. Flight-representative fiber optic cables were subjected to extreme temperature thermal cycling of the same diurnal depth (or delta T) as expected in flight, but for three times the expected number of in-flight thermal cycles. The survivability of fiber optic cables was tested for 600 cumulative thermal cycles from -130 to +15 C to cover the winter season, and another 1,410 cumulative cycles from -105 to +40 C to cover the summer season. This test satisfies the required 3 times the design margin that is a total of 2,010 thermal cycles (670 x 3). This development test included functional optical transmission tests during the course of the test. Transmission of the fiber optic cables was performed prior to and after 1,288 thermal cycles and 2,010 thermal cycles. No significant changes in transmission were observed on either of the two representative fiber cables subject through the 3X MSL mission life that is 2,010 thermal cycles.

  1. Corner strength enhancement of high strength cold-formed steel at normal room and elevated temperatures

    Institute of Scientific and Technical Information of China (English)

    Ju CHEN; Wei-liang JIN

    2008-01-01

    In this study,the suitability of current design methods for the 0.2% proof yield strength of the comer regions for high strength cold-formed steel at norrnal room temperature was investigated.The current standard predictions are generally accurate for outer comer specimen but conservative for inner comer specimen.Based on the experimental results,an analytical model to predict the comer strength of high strength cold-formed steel at normal room temperature was also proposed.The comparison indicated that the proposed model predicted well the comer strength of high strength cold-formed steel not only at normal room temperature but also at elevated temperatures.It is shown that the predictions obtained from the proposed model agree well with the test results.Generally the comer strength enhancement of high strength cold-formed steel decreases when the temperature increases.

  2. Effects of local heat and cold treatment on surface and articular temperature of arthritic knees

    NARCIS (Netherlands)

    Oosterveld, Frederikus G.J.; Rasker, Johannes J.

    1994-01-01

    Objective: To evaluate and compare the effects of locally applied heat and cold treatments on skin and intraarticular temperature in patients with arthritis. Methods. Thirty-nine patients with arthritis of the knee were divided at random into 4 treatment groups (ice chips, nitrogen cold air, ligno-

  3. Baby, It's Cold Outside: Host-Microbiota Relationships Drive Temperature Adaptations.

    Science.gov (United States)

    Gomez de la Torre Canny, Sol; Rawls, John F

    2015-12-09

    When exposed to cold temperatures, mammals undergo remarkable physiological adaptations including thermogenesis, increased intake of dietary energy, and enhanced capacity for intestinal absorption. In a recent Cell paper, Chevalier, Stojanović, and colleagues reveal that these key adaptations to life in the cold are facilitated by the intestinal microbiota (Chevalier et al., 2015). Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Probe for temperature logging of deep cold boreholes

    Science.gov (United States)

    Zangirolami, M.; Cavagnero, G.; Rossi, A.

    2003-04-01

    A new probe has been developed for measuring some physical parameters in deep cold boreholes such as those of the European Project for Ice Coring in Antarctica (EPICA), which is targeted to drill two holes through the ice sheet down to the bedrock at DOME C and at Dronning Maud Land, Antarctica. The probe is operative in the temperature range 0 to -60^oC and for pressures up to 35 MPa, down to 3500 m depth and in the presence of aggressive fluid filling. The probe is equipped with : 1) a set of four thermometers. Three are fitted in the expandable arms of the probe, to log the temperature of the ice-wall. The fourth thermometer is fitted into a static arm in a central position, between the previous three, and logs the temperature of the borehole fluid, for comparison. Thermistor-type sensors have been selected, with a resolution of 2 mK in the interval near 0^oC. During laboratory tests a time constant of 2.7 s was obtained for the thermal sensors fitted in their protective case. After final assemblage of the probe the sensors were calibrated in the laboratory against a standard precision thermometer, over the range 0 to -60^oC; 2) a sensor for differential measurement of the pressure of the liquid column of the drill fluid, with a resolution of a few 10-6 MPa, sufficient to detect any convective cells, induced by the dishomogeneous composition of the mixing fluids; 3) a manometer (strain gauge) for measuring the hydrostatic pressure of the fluid column in the full range 0 to 35 MPa, from the surface to bottom hole, with a resolution better than 0.001 of the full range; 4) a vertical depth meter for direct measurement of depth on the wall of the borehole, to eliminate any uncertainties caused by variations in the length of the electro-mechanical drilling wire due to the fatigue and strain of drilling operations. The progressive depths are measured by a wheel counter and encoder on the upper arms of the probe, with an expected resolution better than 10-3; 5) a

  5. Validation of standard ASTM F2732 and comparison with ISO 11079 with respect to comfort temperature ratings for cold protective clothing.

    Science.gov (United States)

    Gao, Chuansi; Lin, Li-Yen; Halder, Amitava; Kuklane, Kalev; Holmér, Ingvar

    2015-01-01

    American standard ASTM F2732 estimates the lowest environmental temperature for thermal comfort for cold weather protective clothing. International standard ISO 11079 serves the same purpose but expresses cold stress in terms of required clothing insulation for a given cold climate. The objective of this study was to validate and compare the temperature ratings using human subject tests at two levels of metabolic rates (2 and 4 MET corresponding to 116.4 and 232.8 W/m(2)). Nine young and healthy male subjects participated in the cold exposure at 3.4 and -30.6 °C. The results showed that both standards predict similar temperature ratings for an intrinsic clothing insulation of 1.89 clo and for 2 MET activity. The predicted temperature rating for 2 MET activity is consistent with test subjects' thermophysiological responses, perceived thermal sensation and thermal comfort. For 4 MET activity, however, the whole body responses were on the cold side, particularly the responses of the extremities. ASTM F2732 is also limited due to its omission and simplification of three climatic variables (air velocity, radiant temperature and relative humidity) and exposure time in the cold which are of practical importance.

  6. Temperature limit values for cold touchable surfaces ' ColdSurf ' : final report

    NARCIS (Netherlands)

    Holmer, I.; Havenith, G.; Hartog, E.A. den; Rintamaki, H.; Malchaire, J.

    2000-01-01

    The aim of the project was to find and compile information on human responses to contact with cold surfaces. The work has covered 1) literature search and field survey; 2) experimental studies with human subjects; 3) simulation by modeling; 4) instrumentation (artificial finger), 5) establishment of

  7. Cold-water coral growth under extreme environmental conditions, the Cape Lookout area, NW Atlantic

    NARCIS (Netherlands)

    Mienis, F.; Duineveld, G.C.A.; Davis, A.J.; Lavaleye, M.M.S.; Rosso, S.W.; Seim, H.; Bane, J.; van Haren, H.; Bergman, M.J.N.; de Haas, H.; Brooke, S.; van Weering, T.C.E.

    2014-01-01

    The Cape Lookout cold-water coral area off thecoast of North Carolina forms the shallowest and northernmostcold-water coral mound area on the Blake Plateau inthe NW Atlantic. Cold-water coral habitats near Cape Lookoutare occasionally bathed in the Gulf Stream, which is characterisedby oligotrophic

  8. Regional amplification of projected changes in extreme temperatures strongly controlled by soil moisture-temperature feedbacks

    Science.gov (United States)

    Vogel, M. M.; Orth, R.; Cheruy, F.; Hagemann, S.; Lorenz, R.; Hurk, B. J. J. M.; Seneviratne, S. I.

    2017-02-01

    Regional hot extremes are projected to increase more strongly than global mean temperature, with substantially larger changes than 2°C even if global warming is limited to this level. We investigate the role of soil moisture-temperature feedbacks for this response based on multimodel experiments for the 21st century with either interactive or fixed (late 20th century mean seasonal cycle) soil moisture. We analyze changes in the hottest days in each year in both sets of experiments, relate them to the global mean temperature increase, and investigate processes leading to these changes. We find that soil moisture-temperature feedbacks significantly contribute to the amplified warming of the hottest days compared to that of global mean temperature. This contribution reaches more than 70% in Central Europe and Central North America. Soil moisture trends are more important for this response than short-term soil moisture variability. These results are relevant for reducing uncertainties in regional temperature projections.

  9. Whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults.

    Science.gov (United States)

    Costello, Joseph T; Baker, Philip R A; Minett, Geoffrey M; Bieuzen, Francois; Stewart, Ian B; Bleakley, Chris

    2015-09-18

    Recovery strategies are often used with the intention of preventing or minimising muscle soreness after exercise. Whole-body cryotherapy, which involves a single or repeated exposure(s) to extremely cold dry air (below -100 °C) in a specialised chamber or cabin for two to four minutes per exposure, is currently being advocated as an effective intervention to reduce muscle soreness after exercise. To assess the effects (benefits and harms) of whole-body cryotherapy (extreme cold air exposure) for preventing and treating muscle soreness after exercise in adults. We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, the British Nursing Index and the Physiotherapy Evidence Database. We also searched the reference lists of articles, trial registers and conference proceedings, handsearched journals and contacted experts.The searches were run in August 2015. We aimed to include randomised and quasi-randomised trials that compared the use of whole-body cryotherapy (WBC) versus a passive or control intervention (rest, no treatment or placebo treatment) or active interventions including cold or contrast water immersion, active recovery and infrared therapy for preventing or treating muscle soreness after exercise in adults. We also aimed to include randomised trials that compared different durations or dosages of WBC. Our prespecified primary outcomes were muscle soreness, subjective recovery (e.g. tiredness, well-being) and adverse effects. Two review authors independently screened search results, selected studies, assessed risk of bias and extracted and cross-checked data. Where appropriate, we pooled results of comparable trials. The random-effects model was used for pooling where there was substantial heterogeneity. We assessed the quality of the evidence using GRADE. Four laboratory-based randomised controlled trials were included. These reported results for 64

  10. Extreme Environment Silicon Carbide Hybrid Temperature & Pressure Optical Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Nabeel Riza

    2010-09-01

    This final report contains the main results from a 3-year program to further investigate the merits of SiC-based hybrid sensor designs for extreme environment measurements in gas turbines. The study is divided in three parts. Part 1 studies the material properties of SiC such as temporal response, refractive index change with temperature, and material thermal response reversibility. Sensor data from a combustion rig-test using this SiC sensor technology is analyzed and a robust distributed sensor network design is proposed. Part 2 of the study focuses on introducing redundancy in the sensor signal processing to provide improved temperature measurement robustness. In this regard, two distinct measurement methods emerge. A first method uses laser wavelength sensitivity of the SiC refractive index behavior and a second method that engages the Black-Body (BB) radiation of the SiC package. Part 3 of the program investigates a new way to measure pressure via a distance measurement technique that applies to hot objects including corrosive fluids.

  11. Change in Unusually Hot and Cold Temperatures in the Contiguous 48 States, 1948-2015

    Data.gov (United States)

    U.S. Environmental Protection Agency — This map shows trends in unusually hot and cold temperatures at individual weather stations that have operated consistently since 1948. In this case, the term...

  12. Assessment of SOI AND Gate, Type CHT-7408, for Operation in Extreme Temperature Environments

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad; Dones, Keishla Rivera

    2009-01-01

    Electronic parts based on silicon-on-insulator (SOI) technology are finding widespread applications due to their ability to operate in harsh environments and the benefits they offer as compared to their silicon counterparts. Due to their construction, they are tailored for high temperature operation and show good tolerance to radiation events. In addition, their inherent design lessens the formation of parasitic junctions, thereby reducing leakage currents, decreasing power consumption, and enhancing speed. These devices are typically rated in temperature capability from -55 C to about +225 C, and their characteristics over this temperature range are documented in data sheets. Since electronics in some of NASA space exploration missions are required to operate under extreme temperature conditions, both cold and hot, their characteristic behavior within the full temperature spectrum must be determined to establish suitability for use in space applications. The effects of extreme temperature exposure on the performance of a new commercial-off-the-shelf (COTS) SOI AND gate device were evaluated in this work. The high temperature, quad 2-inputs AND gate device, which was recently introduced by CISSOID, is fabricated using a CMOS SOI process. Some of the specifications of the CHT-7408 chip are listed in a table. By supplying a constant DC voltage to one gate input and a 10 kHz square wave into the other associated gate input, the chip was evaluated in terms of output response, output rise (t(sub r)) and fall times (tf), and propagation delays (using a 50% level between input and output during low to high (tPLH) and high to low (tPHL) transitions). The supply current of the gate circuit was also obtained. These parameters were recorded at various test temperatures between -195 C and +250 C using a Sun Systems environmental chamber programmed at a temperature rate of change of 10 C/min. In addition, the effects of thermal cycling on this chip were determined by exposing

  13. Evaluation of extreme temperature events in northern Spain based on process control charts

    Science.gov (United States)

    Villeta, M.; Valencia, J. L.; Saá, A.; Tarquis, A. M.

    2017-02-01

    Extreme climate events have recently attracted the attention of a growing number of researchers because these events impose a large cost on agriculture and associated insurance planning. This study focuses on extreme temperature events and proposes a new method for their evaluation based on statistical process control tools, which are unusual in climate studies. A series of minimum and maximum daily temperatures for 12 geographical areas of a Spanish region between 1931 and 2009 were evaluated by applying statistical process control charts to statistically test whether evidence existed for an increase or a decrease of extreme temperature events. Specification limits were determined for each geographical area and used to define four types of extreme anomalies: lower and upper extremes for the minimum and maximum anomalies. A new binomial Markov extended process that considers the autocorrelation between extreme temperature events was generated for each geographical area and extreme anomaly type to establish the attribute control charts for the annual fraction of extreme days and to monitor the occurrence of annual extreme days. This method was used to assess the significance of changes and trends of extreme temperature events in the analysed region. The results demonstrate the effectiveness of an attribute control chart for evaluating extreme temperature events. For example, the evaluation of extreme maximum temperature events using the proposed statistical process control charts was consistent with the evidence of an increase in maximum temperatures during the last decades of the last century.

  14. Need for Caution in Interpreting Daily Temperature Extremes

    Science.gov (United States)

    Sardeshmukh, P. D.; Compo, G. P.; Penland, C.

    2014-12-01

    Given the substantial anthropogenic contribution to global warming, it is tempting to seek an anthropogenic component in any unusual recent weather event, or more generally in any recent change in extreme weather statistics. We caution that such detection and attribution efforts may, however, lead to wrong conclusions if the distinctively skewed and heavy-tailed features of the probability distributions of daily weather variations are not properly accounted for. Large deviations from the mean are far more common in such a non-Gaussian world than they are in a Gaussian world. In such a world, a mean climate shift is also generally accompanied by changes in the width and shape of the probability distribution. Consequently, even the sign of the changes in tail probabilities cannot be inferred unequivocally from the mean shift. These realities further complicate the establishment of significant changes in tail probabilities from historical records of limited length and accuracy. A possible solution is to exploit the fact that the salient non-Gaussian features of the observed distributions are captured in a general class of probability distributions introduced in the meteorological literature by Sardeshmukh and Sura (2009). These distributions, called Stochastically Generated Skewed (SGS) distributions (of which Gaussian distributions are special cases), are associated with modified forms of stochastically perturbed damped linear processes, and as such represent perhaps the simplest physically based non-Gaussian prototypes of the observed distributions. Importantly, the distribution of an SGS variable remains an SGS distribution under a mean climate shift. We show further that fitting SGS distributions to all daily values in limited climate records yields extreme value distributions of block maxima with smaller sampling uncertainties than GEV distributions fitted to only the block maxima. Extreme value analysis based on SGS distributions thus provides an attractive

  15. Performance of High Temperature Operational Amplifier, Type LM2904WH, under Extreme Temperatures

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik

    2008-01-01

    Operation of electronic parts and circuits under extreme temperatures is anticipated in NASA space exploration missions as well as terrestrial applications. Exposure of electronics to extreme temperatures and wide-range thermal swings greatly affects their performance via induced changes in the semiconductor material properties, packaging and interconnects, or due to incompatibility issues between interfaces that result from thermal expansion/contraction mismatch. Electronics that are designed to withstand operation and perform efficiently in extreme temperatures would mitigate risks for failure due to thermal stresses and, therefore, improve system reliability. In addition, they contribute to reducing system size and weight, simplifying its design, and reducing development cost through the elimination of otherwise required thermal control elements for proper ambient operation. A large DC voltage gain (100 dB) operational amplifier with a maximum junction temperature of 150 C was recently introduced by STMicroelectronics [1]. This LM2904WH chip comes in a plastic package and is designed specifically for automotive and industrial control systems. It operates from a single power supply over a wide range of voltages, and it consists of two independent, high gain, internally frequency compensated operational amplifiers. Table I shows some of the device manufacturer s specifications.

  16. Extreme operative temperatures are better descriptors of the thermal environment than mean temperatures.

    Science.gov (United States)

    Camacho, Agustín; Trefaut Rodrigues, Miguel; Navas, Carlos

    2015-01-01

    In ecological studies of thermal biology the thermal environment is most frequently described using the mean or other measures of central tendency in environmental temperatures. However, this procedure may hide biologically relevant thermal variation for ectotherms, potentially misleading interpretations. Extremes of operative temperatures (EOT) can help with this problem by bracketing the thermal environment of focal animals. Within this paper, we quantify how mean operative temperatures relate to the range of simultaneously available operative temperatures (a measure of error). We also show how EOT: 1) detect more thermal differences among microsites than measures of central tendency, like the mean OT, 2) allow inferring on microsite use by ectothermic animals, and 3) clarify the relationships between field operative temperatures and temperatures measured at weather stations (WS). To do that, we explored operative temperatures measured at four sites of the Brazilian Caatingas and their correspondent nearest weather stations. We found that the daily mean OT can hide temperature ranges of 41 °C simultaneously available at our study sites. In addition, EOT detected more thermal differences among microsites than central quantiles. We also show how EOT allow inferring about microsite use of ectothermic animals in a given site. Finally, the daily maximum temperature and the daily temperature range measured at WSs predicted well the minimum available field OT at localities many kilometers away. Based on our results, we recommend the use of EOT, instead of mean OT, in thermal ecology studies.

  17. Numerical analysis for random temperature fields of embankment in cold regions

    Institute of Scientific and Technical Information of China (English)

    LIU ZhiQiang; LAI YuanMing; ZHANG MingYi; ZHANG XueFu

    2007-01-01

    The stochastic finite element equations for random temperature are obtained using the first-order perturbation technique taking into account the random thermal properties and boundary condition,based on heat transfer variational principle.The local average method for 2-D is used to discretize random fields.Then,the random temperature fields of embankment in cold regions are investigated on condition that the thermal properties and boundary condition are taken as random fields,respectively,by using the program,which is written by the methods.The expected value of temperature field and the standard deviation of the temperature field of embankment in cold regions are obtained and analyzed.

  18. Numerical analysis for random temperature fields of embankment in cold regions

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The stochastic finite element equations for random temperature are obtained using the first-order per-turbation technique taking into account the random thermal properties and boundary condition, based on heat transfer variational principle. The local average method for 2-D is used to discretize random fields. Then, the random temperature fields of embankment in cold regions are investigated on condi-tion that the thermal properties and boundary condition are taken as random fields, respectively, by using the program, which is written by the methods. The expected value of temperature field and the standard deviation of the temperature field of embankment in cold regions are obtained and analyzed.

  19. Synoptic conditions leading to extremely high temperatures in Madrid

    Directory of Open Access Journals (Sweden)

    R. García

    Full Text Available Extremely hot days (EHD in Madrid have been analysed to determine the synoptic patterns that produce EHDs during the period of 1955–1998. An EHD is defined as a day with maximum temperature higher than 36.5°C, a value which is the threshold for the intense effects on mortatility and it coincides with the 95 percentile of the series. Two different situations have been detected as being responsible for an EHD occurrence, one more dynamical, produced by southern fluxes, and another associated with a stagnation situation over Iberia of a longer duration. Both account for 92% of the total number of days, thus providing an efficient classification framework. A circulation index has been derived to characterise and forecast an EHD occurrence. This paper shows that EHD occur in Madrid during short duration events, and no long heat waves, like those recorded in other cities, are present. Additionally, no clear pattern can be detected in the EHD frequency; the occurrence is tied to changes in the summer location of the Azores high.

    Key words. Meteorology and atmospheric dynamics (Climatology; synoptic-scale meteorology; general or miscellaneous

  20. Synoptic conditions leading to extremely high temperatures in Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, R.; Prieto, L.; Hernandez, E.; Teso, T. del [Dept. Fisica de la Tierra II, Fac. CC. Fisicas, Univ. Camplutense de Madrid (Spain); Diaz, J. [Centro Universitario de Salud Publica, Univ. Autonoma de Madrid (Spain)

    2002-02-01

    Extremely hot days (EHD) in Madrid have been analysed to determine the synoptic patterns that produce EHDs during the period of 1955-1998. An EHD is defined as a day with maximum temperature higher than 36.5 C, a value which is the threshold for the intense effects on mortatility and it coincides with the 95 percentile of the series. Two different situations have been detected as being responsible for an EHD occurrence, one more dynamical, produced by southern fluxes, and another associated with a stagnation situation over Iberia of a longer duration. Both account for 92% of the total number of days, thus providing an efficient classification framework. A circulation index has been derived to characterise and forecast an EHD occurrence. This paper shows that EHD occur in Madrid during short duration events, and no long heat waves, like those recorded in other cities, are present. Additionally, no clear pattern can be detected in the EHD frequency; the occurrence is tied to changes in the summer location of the Azores high. (orig.)

  1. Determinants and nature of intramuscular temperature changes during cold therapy.

    Science.gov (United States)

    Lowdon, B J; Moore, R J

    1975-10-01

    The purpose of this study was to examine the intramuscular temperature response during an ice massage treatment. In addition, the effect of subcutaneous tissue thickness and limb circumference on temperature changes was investigated. Intramuscular temperature was measured by intramuscular thermocouples each minute during ice massage treatments of five, ten and fifteen minutes. It was shown that ice massage produces a significant drop in intramuscular temperature. However, there was no significant difference in temperature change after five minutes of treatment. In addition it was shown that there is a high multiple correlation between logarithmic time, subcutaneous tissue thickness, limb circumference, and intramuscular temperature change.

  2. Thermal discomfort with cold extremities in relation to age, gender, and body mass index in a random sample of a Swiss urban population

    Directory of Open Access Journals (Sweden)

    Orgül Selim

    2010-06-01

    Full Text Available Abstract Background The aim of this epidemiological study was to investigate the relationship of thermal discomfort with cold extremities (TDCE to age, gender, and body mass index (BMI in a Swiss urban population. Methods In a random population sample of Basel city, 2,800 subjects aged 20-40 years were asked to complete a questionnaire evaluating the extent of cold extremities. Values of cold extremities were based on questionnaire-derived scores. The correlation of age, gender, and BMI to TDCE was analyzed using multiple regression analysis. Results A total of 1,001 women (72.3% response rate and 809 men (60% response rate returned a completed questionnaire. Statistical analyses revealed the following findings: Younger subjects suffered more intensely from cold extremities than the elderly, and women suffered more than men (particularly younger women. Slimmer subjects suffered significantly more often from cold extremities than subjects with higher BMIs. Conclusions Thermal discomfort with cold extremities (a relevant symptom of primary vascular dysregulation occurs at highest intensity in younger, slimmer women and at lowest intensity in elderly, stouter men.

  3. Effect of cold water and inverse lighting on growth performance of broiler chickens under extreme heat stress.

    Science.gov (United States)

    Park, Sang-oh; Park, Byung-sung; Hwangbo, Jong

    2015-07-01

    The present study was carried out to investigate the effect of provision of extreme heat stress diet (EHD), inverse lighting, cold water on growth performance of broiler chickens exposed to extreme heat stress. The chickens were divided into four treatment groups, (T1, T2, T3, T4) as given below: Ti (EHD 1, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T2 (EHD 2, 10:00-19:00 dark, 19:00-10:00 light, cool water 9 degrees C); T3 (EHD 1, 09:00-18:00 dark, 18:00-09:00 light, cool water 141C); T4 (EHD 2, 09:00-18:00 dark, 18:00-09:00 light, cool water 14 degrees C. EHD 1 contained soybean oil, molasses, methionine and lysine; EHD 2 contained the same ingredients as EHD 1 with addition of vitamin C. Groups T1 and T2 were given cooler water than the othertwo groups, and displayed higher body weight increase and diet intake as compared to T3 and T4 (pstress diet, inverse lighting (10:00-19:00 dark, 19:00-10:00 light) with cold water at 9 degrees C under extreme heat stress could enhance growth performance of broiler chickens.

  4. In-Situ Acoustic Measurements of Temperature Profile in Extreme Environments

    Energy Technology Data Exchange (ETDEWEB)

    Skliar, Mikhail [Univ. of Utah, Salt Lake City, UT (United States)

    2015-03-31

    A gasifier’s temperature is the primary characteristic that must be monitored to ensure its performance and the longevity of its refractory. One of the key technological challenges impacting the reliability and economics of coal and biomass gasification is the lack of temperature sensors that are capable of providing accurate, reliable, and long-life performance in an extreme gasification environment. This research has proposed, demonstrated, and validated a novel approach that uses a noninvasive ultrasound method that provides real-time temperature distribution monitoring across the refractory, especially the hot face temperature of the refractory. The essential idea of the ultrasound measurements of segmental temperature distribution is to use an ultrasound propagation waveguide across a refractory that has been engineered to contain multiple internal partial reflectors at known locations. When an ultrasound excitation pulse is introduced on the cold side of the refractory, it will be partially reflected from each scatterer in the US propagation path in the refractory wall and returned to the receiver as a train of partial echoes. The temperature in the corresponding segment can be determined based on recorded ultrasonic waveform and experimentally defined relationship between the speed of sound and temperature. The ultrasound measurement method offers a powerful solution to provide continuous real time temperature monitoring for the occasions that conventional thermal, optical and other sensors are infeasible, such as the impossibility of insertion of temperature sensor, harsh environment, unavailable optical path, and more. Our developed ultrasound system consists of an ultrasound engineered waveguide, ultrasound transducer/receiver, and data acquisition, logging, interpretation, and online display system, which is simple to install on the existing units with minimal modification on the gasifier or use with new units. This system has been successfully tested

  5. Quantitative risk assessment of the effects of drought on extreme temperature in eastern China

    Science.gov (United States)

    Hao, Zengchao; Hao, Fanghua; Singh, Vijay P.; Ouyang, Wei

    2017-09-01

    Hot extremes may lead to disastrous impacts on human health and agricultural production. Previous studies have revealed the feedback between drought and hot extremes in large regions of eastern China, while quantifying the impact of antecedent drought on hot extremes has been limited. This study aims at quantitatively assessing the risk of extreme temperature conditioned on the antecedent drought condition represented by Standardized Precipitation Index (SPI) during summer time in eastern China. A copula-based model is proposed to construct the joint probability distribution of extreme temperature and drought based on 6 month SPI (SPI6). Accordingly, the conditional probability distribution is employed to quantify impacts of antecedent dry (and wet) conditions on the exceedance probability of extreme temperature. Results show that the likelihood of extreme temperature exceeding high quantiles is higher given antecedent dry conditions than that given antecedent wet conditions in large regions from southwestern to northeastern China. Specifically, the conditional probability difference of temperature exceeding 80th percentile given SPI6 lower than or equal to -0.5 and SPI6 higher than 0.5 is around 0.2-0.3. The case study of the 2006 summer hot extremes and drought in Sichuan and Chongqing region shows that the conditional return period of extreme temperature conditioned on antecedent drought is around 5-50 years shorter than univariate return period. These results quantify the impact of antecedent drought on subsequent extreme temperature and highlight the important role of antecedent drought in intensifying hot extremes in these regions.

  6. Geo-spatial analysis of temporal trends of temperature and its extremes over India using daily gridded (1°×1°) temperature data of 1969-2005

    Science.gov (United States)

    Chakraborty, Abhishek; Seshasai, M. V. R.; Rao, S. V. C. Kameswara; Dadhwal, V. K.

    2016-07-01

    Daily gridded (1°×1°) temperature data (1969-2005) were used to detect spatial patterns of temporal trends of maximum and minimum temperature (monthly and seasonal), growing degree days (GDDs) over the crop-growing season (kharif, rabi, and zaid) and annual frequencies of temperature extremes over India. The direction and magnitude of trends, at each grid level, were estimated using the Mann-Kendall statistics (α = 0.05) and further assessed at the homogeneous temperature regions using a field significance test (α=0.05). General warming trends were observed over India with considerable variations in direction and magnitude over space and time. The spatial extent and the magnitude of the increasing trends of minimum temperature (0.02-0.04 °C year-1) were found to be higher than that of maximum temperature (0.01-0.02 °C year-1) during winter and pre-monsoon seasons. Significant negative trends of minimum temperature were found over eastern India during the monsoon months. Such trends were also observed for the maximum temperature over northern and eastern parts, particularly in the winter month of January. The general warming patterns also changed the thermal environment of the crop-growing season causing significant increase in GDDs during kharif and rabi seasons across India. The warming climate has also caused significant increase in occurrences of hot extremes such as hot days and hot nights, and significant decrease in cold extremes such as cold days and cold nights.

  7. Neural models on temperature regulation for cold-stressed animals

    Science.gov (United States)

    Horowitz, J. M.

    1975-01-01

    The present review evaluates several assumptions common to a variety of current models for thermoregulation in cold-stressed animals. Three areas covered by the models are discussed: signals to and from the central nervous system (CNS), portions of the CNS involved, and the arrangement of neurons within networks. Assumptions in each of these categories are considered. The evaluation of the models is based on the experimental foundations of the assumptions. Regions of the nervous system concerned here include the hypothalamus, the skin, the spinal cord, the hippocampus, and the septal area of the brain.

  8. Temperature Variation and Heat Wave and Cold Spell Impacts on Years of Life Lost Among the Urban Poor Population of Nairobi, Kenya

    Directory of Open Access Journals (Sweden)

    Thaddaeus Egondi

    2015-03-01

    Full Text Available Weather extremes are associated with adverse health outcomes, including mortality. Studies have investigated the mortality risk of temperature in terms of excess mortality, however, this risk estimate may not be appealing to policy makers assessing the benefits expected for any interventions to be adopted. To provide further evidence of the burden of extreme temperatures, we analyzed the effect of temperature on years of life lost (YLL due to all-cause mortality among the population in two urban informal settlements. YLL was generated based on the life expectancy of the population during the study period by applying a survival analysis approach. Association between daily maximum temperature and YLL was assessed using a distributed lag nonlinear model. In addition, cold spell and heat wave effects, as defined according to different percentiles, were investigated. The exposure-response curve between temperature and YLL was J-shaped, with the minimum mortality temperature (MMT of 26 °C. An average temperature of 21 °C compared to the MMT was associated with an increase of 27.4 YLL per day (95% CI, 2.7–52.0 years. However, there was no additional effect for extended periods of cold spells, nor did we find significant associations between YLL to heat or heat waves. Overall, increased YLL from all-causes were associated with cold spells indicating the need for initiating measure for reducing health burdens.

  9. Temperature and number evolution of cold cesium atoms inside a wall-coated glass cell

    Institute of Scientific and Technical Information of China (English)

    黄家强; 张建伟; 王时光; 王力军

    2015-01-01

    We report an experimental study on the temperature and number evolution of cold cesium atoms diffusively cooled inside a wall-coated glass cell by measuring the absorption profile of the 62S1/2 (F=4)→62P3/2(F0=5) transition line with a weak probe laser in the evolution process. We found that the temperature of the cold atoms first gradually decreases from 16 mK to 9 mK, and then rapidly increases. The number of cold atoms first declines slowly from 2.1 × 109 to 3.7 × 108 and then falls drastically. A theoretical model for the number evolution is built and includes the instantaneous temperature of the cold atoms and a fraction p, which represents the part of cold cesium atoms elastically reflected by the coated cell wall. The theory is overall in good agreement with the experimental result, and a nonzero value is obtained for the fraction p, which indicates that the cold cesium atoms are not all heated to the ambient temperature by a single collision with the coated cell wall. These results can provide helpful insight for precision measurements based on diffuse laser cooling.

  10. Characterization and effects of cold fronts in the Colombian Caribbean Coast and their relationship to extreme wave events

    Science.gov (United States)

    Ortiz-Royero, J. C.; Otero, L. J.; Restrepo, J. C.; Ruiz, J.; Cadena, M.

    2013-07-01

    Extreme ocean waves in the Caribbean Sea are commonly related to the effects of storms and hurricanes during the months of June through November. The collapse of 200 m of the Puerto Colombia pier in March 2009 revealed the effects of meteorological phenomena other than storms and hurricanes that may be influencing the extreme wave regime in the Colombian Caribbean. The marked seasonality of these atmospheric fronts was established by analyzing the meteorological-marine reports of Instituto de Hidrología, Meteorología y Estudios Ambientales of Colombia (IDEAM, based on its initials in Spanish) and Centro de Investigación en Oceanografía y Meteorología of Colombia (CIOH, based on its initials in Spanish). The highest occurrences were observed during the months of January, February, and March, with 6 fronts occurring per year. An annual trend was not observed, although the highest number of fronts occurred in 2010 (20 in total). An annual strong relationship between the maximum average wave values and the cold fronts, in the central zone of the Colombian Caribbean during the first three months of the year was established. In addition, the maximum values of the significant height produced by the passage of cold fronts during the last 16 yr were identified. Although the Colombian Caribbean has been affected by storms and hurricanes in the past, this research allows us to conclude that, there is a strong relationship between cold fronts and the largest waves in the Colombian Caribbean during the last 16 yr, which have caused damage to coastal infrastructure. We verified that the passage of a cold front corresponded to the most significant extreme wave event of the last two decades in the Colombian Caribbean, which caused the structural collapse of the Puerto Colombia pier, located near the city of Barranquilla, between 5 and 10 March 2009. This information is invaluable when evaluating average and extreme wave regimes for the purpose of informing the design of

  11. Investigating temperature breaks in the summer fruit export cold chain: A case study

    Directory of Open Access Journals (Sweden)

    Heinri W. Freiboth

    2013-05-01

    Full Text Available There is concern in the South African fruit industry that a large amount of fruit and money is lost every season due to breaks in the fruit export cold chain. The possibility of a large percentage of losses in a significant sector of the economy warranted further investigation. This article attempted to highlight some of the possible problem areas in the cold chain, from the cold store to the port, by analysing historic temperature data from different fruit export supply chains of apples, pears and grapes. In addition, a trial shipment of apples was used to investigate temperature variation between different pallets in the same container. This research has added value to the South African fruit industry by identifying the need to improve operational procedures in the cold chain.

  12. Cold-Blooded Attention: Finger Temperature Predicts Attentional Performance

    Directory of Open Access Journals (Sweden)

    Rodrigo C. Vergara

    2017-09-01

    Full Text Available Thermal stress has been shown to increase the chances of unsafe behavior during industrial and driving performances due to reductions in mental and attentional resources. Nonetheless, establishing appropriate safety standards regarding environmental temperature has been a major problem, as modulations are also be affected by the task type, complexity, workload, duration, and previous experience with the task. To bypass this attentional and thermoregulatory problem, we focused on the body rather than environmental temperature. Specifically, we measured tympanic, forehead, finger and environmental temperatures accompanied by a battery of attentional tasks. We considered a 10 min baseline period wherein subjects were instructed to sit and relax, followed by three attentional tasks: a continuous performance task (CPT, a flanker task (FT and a counting task (CT. Using multiple linear regression models, we evaluated which variable(s were the best predictors of performance. The results showed a decrement in finger temperature due to instruction and task engagement that was absent when the subject was instructed to relax. No changes were observed in tympanic or forehead temperatures, while the environmental temperature remained almost constant for each subject. Specifically, the magnitude of the change in finger temperature was the best predictor of performance in all three attentional tasks. The results presented here suggest that finger temperature can be used as a predictor of alertness, as it predicted performance in attentional tasks better than environmental temperature. These findings strongly support that peripheral temperature can be used as a tool to prevent unsafe behaviors and accidents.

  13. Soil temperature regime and vulnerability due to extreme soil temperatures in Croatia

    Science.gov (United States)

    Sviličić, Petra; Vučetić, Višnja; Filić, Suzana; Smolić, Ante

    2016-10-01

    Soil temperature is an important factor within the climate system. Changes of trends in soil temperature and analysis of vulnerability due to heat stress can provide useful information on climate change. In this paper, the soil temperature regime was analyzed on seasonal and annual scales at depths of 2, 5, 10, 20, 30, and 50 cm at 26 sites in Croatia. Trends of maximal, mean, and minimal soil temperatures were analyzed in the periods 1961-2010 and 1981-2010. Duration of extreme soil temperatures and vulnerability due to high or low soil temperatures in the recent standard period 1981-2010 was compared with the reference climate period 1961-1990. The results show a general warming in all seasons and depths for maximal and mean temperatures in both observed periods, while only at some locations for minimal soil temperature. Warming is more pronounced in the eastern and coastal parts of Croatia in the surface layers, especially in the spring and summer season in the second period. Significant trends of maximal, minimal, and mean soil temperature in both observed periods range from 2.3 to 6.6 °C/decade, from -1.0 to 1.3 °C/decade, and from 0.1 to 2.5 °C/decade, respectively. The highest vulnerability due to heat stress at 35 °C is noted in the upper soil layers of the coastal area in both observed periods. The mountainous and northwestern parts of Croatia at surface soil layers are the most vulnerable due to low soil temperature below 0 °C. Vulnerability due to high or low soil temperature decreases with depth.

  14. Dynamical Influence and Operational Impacts of an Extreme Mediterranean Cold Surge

    Science.gov (United States)

    2013-06-01

    in significant flooding over regions surrounding the Mediterranean Sea ( Trigo , Bigg, & Davies 2002). The cold air mass and associated cyclogenesis...119, 17–55. Trigo , I., G. Bigg, and T. Davies, 2002: Climatology of cyclogenesis mechanisms in the Mediterranean. Mon. Wea. Rev., 130, 549–569

  15. The Role of Rossby-Wave Propagation in a North American Extreme Cold Event

    Directory of Open Access Journals (Sweden)

    Chunhua Shi

    2017-01-01

    Full Text Available The Eliassen–Palm flux and Plumb wave activity flux are calculated using the European Centre for Medium-Range Weather Forecasts interim reanalysis daily dataset to determine the propagation of Rossby waves before a North American cold wave in January 2014. The results show that the upward wave activity fluxes mainly come from planetary waves 1 and 2, which provide a stable circulation background for the influence of the subplanetary-scale waves 3 and 4. The Rossby-wave propagation anomalies between the troposphere and the stratosphere are due to the modulating effects of waves 3 and 4 on waves 1 and 2. During 9–14 January 2014, the modulating effects helped strengthen upward and eastward wave activity fluxes over the Atlantic region and enhance the Pacific high in the stratosphere in its early stage. Later in 19–24 January, the downward wave activity fluxes over the east Pacific due to the modulating effects were beneficial to downward development of the stratospheric high over the Pacific and the formation of a blocking high over the west coast of North America in the troposphere accompanied by a strong adjacent cold low on the east side. These circulations benefit the southward invasion of polar cold air reaching the lower latitudes of east North America, leading to the cold wave outbreak.

  16. Temperature-difference-driven mass transfer through the vapor from a cold to a warm liquid

    NARCIS (Netherlands)

    Struchtrup, H.; Kjelstrup, S.H.; Bedeaux, D.

    2012-01-01

    Irreversible thermodynamics provides interface conditions that yield temperature and chemical potential jumps at phase boundaries. The interfacial jumps allow unexpected transport phenomena, such as the inverted temperature profile [ Pao Phys. Fluids 14 306 (1971)] and mass transfer from a cold to a

  17. Packhouse to port: Investigating temperature breaks in the South African summer fruit export cold chain

    CSIR Research Space (South Africa)

    Freiboth, H

    2014-10-01

    Full Text Available in refrigerated containers, as it moves from the pack house through the cold storage and transport segments towards the port of export. Historic temperature data collected with temperature monitoring devices from different fruit export supply chains of apples...

  18. Temperature-difference-driven mass transfer through the vapor from a cold to a warm liquid

    NARCIS (Netherlands)

    Struchtrup, H.; Kjelstrup, S.H.; Bedeaux, D.

    2012-01-01

    Irreversible thermodynamics provides interface conditions that yield temperature and chemical potential jumps at phase boundaries. The interfacial jumps allow unexpected transport phenomena, such as the inverted temperature profile [ Pao Phys. Fluids 14 306 (1971)] and mass transfer from a cold to a

  19. Climate change impacts on extreme temperature mortality in select metropolitan areas of the United States

    Science.gov (United States)

    Projected mortality from climate change-driven impacts on extremely hot and cold days increases significantly over the 21st century in a large group of United States Metropolitan Statistical Areas. Increases in projected mortality from more hot days are greater than decreases in ...

  20. Nocturnal loss of body reserves reveals high survival risk for subordinate great tits wintering at extremely low ambient temperatures.

    Science.gov (United States)

    Krams, Indrikis; Cīrule, Dina; Vrublevska, Jolanta; Nord, Andreas; Rantala, Markus J; Krama, Tatjana

    2013-06-01

    Winter acclimatization in birds is a complex of several strategies based on metabolic adjustment accompanied by long-term management of resources such as fattening. However, wintering birds often maintain fat reserves below their physiological capacity, suggesting a cost involved with excessive levels of reserves. We studied body reserves of roosting great tits in relation to their dominance status under two contrasting temperature regimes to see whether individuals are capable of optimizing their survival strategies under extreme environmental conditions. We predicted less pronounced loss of body mass and body condition and lower rates of overnight mortality in dominant great tits at both mild and extremely low ambient temperatures, when ambient temperature dropped down to -43 °C. The results showed that dominant great tits consistently maintained lower reserve levels than subordinates regardless of ambient temperature. However, dominants responded to the rising risk of starvation under low temperatures by increasing their body reserves, whereas subdominant birds decreased reserve levels in harsh conditions. Yet, their losses of body mass and body reserves were always lower than in subordinate birds. None of the dominant great tits were found dead, while five young females and one adult female were found dead in nest boxes during cold spells when ambient temperatures dropped down to -43 °C. The dead great tits lost up to 23.83 % of their evening body mass during cold nights while surviving individuals lost on average 12.78 % of their evening body mass. Our results show that fattening strategies of great tits reflect an adaptive role of winter fattening which is sensitive to changes in ambient temperatures and differs among individuals of different social ranks.

  1. Cold temperature delays wound healing in postharvest sugarbeet roots

    Science.gov (United States)

    Storage temperature affects the rate and extent of wound-healing in a number of root and tuber crops. The effect of storage temperature on wound-healing in sugarbeet (Beta vulgaris L.) roots, however, is largely unknown. Wound-healing of sugarbeet roots was investigated using surface-abraded roots s...

  2. Extreme precipitation and temperature responses to circulation patterns in current climate: statistical approaches

    NARCIS (Netherlands)

    Photiadou, C.

    2015-01-01

    Climate change is likely to influence the frequency of extreme extremes - temperature, precipitation and hydrological extremes, which implies increasing risks for flood and drought events in Europe. In current climate, European countries were often not sufficiently prepared to deal with the great so

  3. Hot experience for cold-adapted microorganisms: temperature sensitivity of soil enzymes

    Science.gov (United States)

    Liu, Shibin; Razavidezfuly, Baharsadat; Kuzyakov, Yakov

    2016-04-01

    The temperature sensitivity of enzymes responsible for organic matter decomposition in cold environment soil, where warming is expected to be greatest is crucial. Based on Michaelis-Menten kinetics and Arrhenius function, we hypothesized that cold-adapted microorganisms will produce high efficient enzymes at cold temperatures (enzymes with lower apparent activation energy (Ea) at cold temperature ranges). To test our hypothesis, 30 g soil of Tibetan Plateau (4100 m a.s.l., annual temperature 2.4 °C) in 4 replicates were incubated for one month over a temperature range of 0-40 °C (with 5 °C steps) and determined the kinetic parameters of six enzymes involved in decomposing organics: cellobiohydrolase and β-glucosidase, which are commonly measured as enzymes responsible for consecutive stages of cellulose degradation; xylanase, which is responsible for breaking down hemicelluloses; acid phosphatase, which mineralizes organic P to phosphate by hydrolyzing phosphoric (mono) ester bonds under acidic conditions. Activities of leucine aminopeptidase and tyrosine aminopeptidase were analyzed to assess the hydrolysis of L-peptide bonds. The apparent activation energy varied between enzymes from 42 (phosphatase) to 54 (cellobiohydrolase) kJ mol-1 corresponding to the Q10 values of the enzyme reactions of 1.8-2.3. The increase of substrate affinity (Km) with temperature was gradual for most tested enzymes from 0-20 °C (enzymes involved in C cycle), (proteases) and 0-40 °C (phosphatase). However, within a high range of temperatures (25-40 °C) the hydrolytic activity was governed by enzymes with nearly constant substrate affinity. Overall, for enzymes involved in C cycle and proteases, a strong increase (30-40%) in Km at high temperatures (25 °C) reflects an expression of multiple isoenzymes each with different temperature optima and probable shift of microbial community. The general trend of catalytic efficiency (Vmax/Km) demonstrated a gradual increase with

  4. Evolution of extreme temperatures over western Iberia; reporting on recent changes and future scenarios

    Science.gov (United States)

    Ramos, Alexandre M.; Trigo, Ricardo M.; Santo, Fátima E.

    2010-05-01

    We report on changes in surface air temperature extremes over mainland Portugal during the period 1941-2006 using daily maximum and minimum temperatures (Tmax and Tmin) from 23 of the most reliable Portuguese station records. Here we have used indices corresponding to the number of days above the 90th and below the 10th percentile for both Tmax and Tmin. This allowed us, to compute trends for the entire period of data (1941-2006) as well as for two consecutive 31-year periods: 1945-1975 (relative cooling period) and 1976-2006 (relative warming period), based on results found by Karl et al, 2000. The most striking results are related with the last period (1976-2006) that reveal a significant increase in extreme heat events for both spring and summer seasons, and a decrease in extreme cold events in winter. In the second part of this work we present an analysis of climate change over Portugal simulated by the Hadley Centre regional climate model (HadRM3) with data obtained from Project PRUDENCE. The ability of the model to reproduce the present climate (1961-1990) is tested and evaluated. For this purpose, values of Tmax and Tmin of all 23 climatological weather stations (1961-1990 climate normals) were aggregated into a new time series. Additionally we have computed the seasonal percentiles in 1% steps (ranging from 1% to 99%). For comparison purposes we have aggregated HadRM3 values into a new time series averaging grid points located closest to the 23 climatological weather stations considered, and computed the corresponding seasonal percentiles in 1% steps. This procedure allowed an objective comparison between the two probability distributions (climatological and simulated by the model), using standard q-q plots. Finally we have evaluated changes of probability distributions for future climate projections under the IPCC emission scenarios (B2 and A2), for the period between 2071-2100 when compared to the present climate (1961-1990) simulated by the model. The

  5. Trends and variability of daily temperature and precipitation extremes during 1960-2012 in the Yangtze River Basin, China

    Science.gov (United States)

    Guan, Yinghui

    2017-04-01

    The variability of surface air temperature and precipitation extremes has been the focus of attention during the past several decades, and may exert a great influence on the global hydrologic cycle and energy balance through thermal forcing. Using daily minimum (TN), maximum temperature (TX) and precipitation from 143 meteorological stations in the Yangtze River Basin (YRB), a suite of extreme climate indices recommended by the Expert Team on Climate Change Detection and Indices, which has rarely been applied in this region, were computed and analyzed during 1960-2012. The results show widespread significant changes in all temperature indices associated with warming in the YRB during 1960-2012. On the whole, cold-related indices, i.e., cold nights, cold days, frost days, icing days and cold spell duration index significantly decreased by -3.45, -1.03, -3.04, -0.42 and -1.6 days/decade, respectively. In contrast, warm-related indices such as warm nights, warm days, summer days, tropical nights and warm spell duration index significantly increased by 2.95, 1.71, 2.16, 1.05 and 0.73 days/decade. Minimum TN, maximum TN, minimum TX and maximum TX increased significantly by 0.42, 0.18, 0.19 and 0.14 °C/decade. Because of a faster increase in minimum temperature than maximum temperature, the diurnal temperature range (DTR) exhibited a significant decreasing trend of -0.09 °C/decade for the whole YRB during 1960-2012. Geographically, stations in the eastern Tibet Plateau and northeastern YRB showed stronger trends in almost all temperature indices. Time series analysis indicated that the YRB was dominated by a general cooling trend before the mid-1980s, but a warming trend afterwards. For precipitation, simple daily intensity index, very wet day precipitation, extremely wet day precipitation, extremely heavy precipitation days, maximum 1-day precipitation, maximum 5-day precipitation and maximum consecutive dry days all increased significantly during 1960-2012. In

  6. Effects of Rice Yield and Quality Across Accumulated Temperature Zone Planting in Cold Area

    Institute of Scientific and Technical Information of China (English)

    Wang Qiu-ju; Liu Feng; Gao Pan; Gao Zhong-chao; Chang Ben-chao; Liu Yan-xia; Zhang Li-li

    2015-01-01

    Five rice varieties were planted to determine the variation of the yield and quality traits in five different regions in a cold area of China. The results showed that the number of the panicles, the number of grains per panicle and percentage of head-milled rice displayed quadratic curves against the accumulated temperature, and the sterile rate decreased with greater accumulated temperature. However, 1 000-grain weight had no correlation with the accumulated temperature and protein content, amylose content and taste also had no obvious relation with the accumulated temperature. The results from the accumulated temperature differed with rice variety, so the temperature insensitive type variety should be proposed for production.

  7. Effect of cold-water immersion duration on body temperature and muscle function.

    Science.gov (United States)

    Peiffer, Jeremiah J; Abbiss, Chris R; Watson, Greig; Nosaka, Ken; Laursen, Paul B

    2009-08-01

    This study compared the effect of 5, 10 and 20 min of cold-water (14 degrees C) immersion on rectal and muscle temperature and neuromuscular function. Twelve cyclists performed four cycling time-to-exhaustion trials in hot conditions (40 degrees C and 40%rh), followed 25 min later by cold-water immersion for 5, 10 or 20 min or 20 min in room temperature (24 degrees C; control). Rectal temperature was measured continuously, and muscle temperature was measured before, immediately after and 45 min after the time-to-exhaustion-test, as well as before and after water immersion. Sixty-second maximal voluntary isometric torque and isokinetic torque of the knee extensors were measured before, immediately after and 55 min after time-to-exhaustion-test. A greater rate of decrease in rectal temperature was observed in all water immersion conditions 45-80 min after time-to-exhaustion-test compared with control. Compared with control, muscle temperature 45 min after time-to-exhaustion-test was lower for all water immersion conditions; however, muscle temperature was lower for the 10- and 20-min conditions compared with 5 min. Isometric torque measured 55 min after time-to-exhaustion-test was lower for all conditions. Isokinetic torque was lower for all conditions immediately and 55-min post-time-to-exhaustion-test. Of the durations measured, 5 min of cold-water immersion appeared as the most appropriate duration for reducing rectal temperature but limiting decreases in muscle temperature.

  8. Future trend of extreme value distributions of wintertime surface air temperatures over Korea and the associated physical changes

    Science.gov (United States)

    Kim, Kwang-Yul; Kim, Ji-Won; Kim, Maeng-Ki; Cho, Chun-Ho

    2013-11-01

    Daily winter temperatures in Korea have been analyzed via CSEOF analysis. Then, each PC time series was detrended and was fitted to an AR (autoregressive) model. Based on the identified AR model, an artificial time series of arbitrary length can be generated by using an arbitrary white-noise time series. In this way, one hundred new sets of PC time series were generated over the period of 1973-2058. Then, the trend for each PC time series was added back to the artificial PC time series extending the trend until 2058. Ultimately, artificial daily winter temperatures in Korea have been constructed by using the artificial PC time series and the original loading vectors derived from the observational data. The 100 new data sets have been investigated in order to understand the winter temperature variability 50 years into the future. Regression analysis in CSEOF space shows that temperature increase in Korea is associated with increased 850-hPa air temperature over most of the Asian domain (97°-153°E × 22°-73°N) and increased 850-hPa geopotential height in the southern part of the domain. As a result, southerly and southeasterly wind anomalies develop carrying positive temperature anomalies northward and northwestward. Both the 200-hPa air temperature and geopotential height changes indicate that there will be fairly significant northward shift of the jet stream in future. The standard deviation of the 200-hPa potential vorticity increases implying that shortwave trough and henceforth baroclinic instability will increase in future. Finally, GEV (Generalized Extreme Value) distribution and GPD (Generalized Pareto distribution) distribution have been compared between the observational records and the future records of the same length. The extreme value distributions based on the synthetic datasets show that warm extreme events will be more extreme in future and cold extreme events, on the other hand, will be less extreme. This study provides an estimate of future

  9. Urine temperature as an index for the core temperature of industrial workers in hot or cold environments

    Science.gov (United States)

    Kawanami, Shoko; Horie, Seichi; Inoue, Jinro; Yamashita, Makiko

    2012-11-01

    Workers working in hot or cold environments are at risk for heat stroke and hypothermia. In Japan, 1718 people including 47 workers died of heat stroke in 2010 (Ministry of Health Labour and Welfare, Japan 2011). While the American Conference of Governmental Industrial Hygienists (ACGIH) recommendation lists the abnormal core temperature of workers as a criterion for halting work, no method has been established for reliably measuring core temperatures at workplaces. ISO 9886 (Ergonomics-evaluation of thermal strain by physiological measurements. ISO copyright office, Geneva, pp 3-14; 2004) recognizes urine temperature as an index of core temperature only at normal temperature. In this study we ascertained whether or not urine temperature could serve as an index for core temperature at temperatures above and below the ISO range. We measured urine temperature of 31 subjects (29.8 ± 11.9 years) using a thermocouple sensor placed in the toilet bowl at ambient temperature settings of 40, 20, and 5˚C, and compared them with rectal temperature. At all ambient temperature settings, urine temperature correlated closely with rectal temperature exhibiting small mean bias. Urine temperature changed in a synchronized manner with rectal temperature at 40˚C. A Bland and Altman analysis showed that the limits of agreement (mean bias ± 2SD) between rectal and urine temperatures were -0.39 to +0.15˚C at 40˚C (95%CI -0.44 to +0.20˚C) and -0.79 to +0.29˚C at 5˚C (-0.89 to +0.39˚C). Hence, urine temperature as measured by the present method is a practical surrogate index for rectal temperature and represents a highly reliable biological monitoring index for assessing hot and cold stresses of workers at actual workplaces.

  10. The Peak Structure and Future Changes of the Relationships Between Extreme Precipitation and Temperature

    Science.gov (United States)

    Wang, Guiling; Wang, Dagang; Trenberth, Kevin E.; Erfanian, Amir; Yu, Miao; Bosilovich, Michael G.; Parr, Dana T.

    2017-01-01

    Theoretical models predict that, in the absence of moisture limitation, extreme precipitation intensity could exponentially increase with temperatures at a rate determined by the Clausius-Clapeyron (C-C) relationship. Climate models project a continuous increase of precipitation extremes for the twenty-first century over most of the globe. However, some station observations suggest a negative scaling of extreme precipitation with very high temperatures, raising doubts about future increase of precipitation extremes. Here we show for the present-day climate over most of the globe,the curve relating daily precipitation extremes with local temperatures has a peak structure, increasing as expected at the low medium range of temperature variations but decreasing at high temperatures. However, this peak-shaped relationship does not imply a potential upper limit for future precipitation extremes. Climate models project both the peak of extreme precipitation and the temperature at which it peaks (T(sub peak)) will increase with warming; the two increases generally conform to the C-C scaling rate in mid- and high-latitudes,and to a super C-C scaling in most of the tropics. Because projected increases of local mean temperature (T(sub mean)) far exceed projected increases of T(sub peak) over land, the conventional approach of relating extreme precipitation to T(sub mean) produces a misleading sub-C-C scaling rate.

  11. Ecosystem Respiration Rates of Arctic Tundra Mesocosms in Response to Cold-Season Temperatures

    Science.gov (United States)

    Oberbauer, S. F.; Moser, J. G.; Olivas, P. C.; Starr, G.; Mortazavi, B.

    2013-12-01

    The cold season in the Arctic extends over 8 to 9 mo, during which air temperatures often reach as low as -40 °C. However, as a result of the insulating layer created by snow cover, temperatures seldom fall below -15 °C, and are likely warm enough to support some metabolism. Little research has been conducted on arctic plants and tundra during the cold season, despite its length and the fact that warming is predicted to be greatest during this period. The primary focus of cold-season research has been on rates of winter ecosystem respiration (ER) for estimates of annual carbon balance. The majority of these measurements during the winter or at winter temperatures indicate that some respiration is occurring. Although rates are low, they may contribute substantially to the annual carbon balance because of the length of the cold season. However, estimates of respiration at low temperatures differ substantially, have been taken at different temperatures using different methodologies, and importantly almost none provide quantitative relationships across a range of temperatures. We measured respiration rates of intact arctic tundra monoliths from 15 to -15 °C at 5 °C steps to facilitate improved model estimates of tundra respiration. Six tundra monoliths (~900 cm2) taken from Toolik Field Station, Alaska were conditioned for the cold season in growth chambers at shortened photoperiods and low, but above-freezing temperatures. Desired temperatures were obtained with a combination of growth chambers and a modified freezer. The average of five samplings of [CO2] at each temperature step was used to estimate the ER rates. Measurements were conducted with a closed system using incubation periods of 30 to 180 min, depending on the temperature. Carbon dioxide concentrations were measured by syringe samples injected into a N2 gas stream flowing through an infrared gas analyzer. Rates of ER calculated on an area basis were close to zero at -15 °C, but increased steadily with

  12. Thermovision Analysis Changes of Human Hand Surface Temperature in Cold Pressor Test

    Directory of Open Access Journals (Sweden)

    Agnieszka Chwałczyńska

    2015-01-01

    Full Text Available The cold pressor test (CTP as a diagnostic method of the circulatory system reactivity may be a basis for the qualification for thermal stimulation therapy. The aim of the work was a thermovisual assessment of the reaction to the Hines and Brown cold pressor test. A group of 30 healthy men in the age of 23.5 ± 0.8 years were examined. The average weight of the examinees was 78.4 ± 9.2 kg, their height 180.7 ± 5.9 cms, and BMI 23.9 ± 2.2 kg/m2. A thermovisual picture of a tested and not tested hand of all the subjects was taken before and after the cold pressor test. Under the influence of cold water the surface temperature of a tested hand has decreased in a statistically significant way by 8.3°C on average, which is 29% of the temperature before the test, whilst the temperature of an untested hand dropped by 0.67°C. The decreases of temperature were not even and there was a statistically significant difference between the dorsal and palmar side of the hand. The correlation between the changes of systolic blood pressure and the hand surface temperature before and after CTP was observed.

  13. Temperature-driven groundwater convection in cold climates

    Science.gov (United States)

    Engström, Maria; Nordell, Bo

    2016-08-01

    The aim was to study density-driven groundwater flow and analyse groundwater mixing because of seasonal changes in groundwater temperature. Here, density-driven convection in groundwater was studied by numerical simulations in a subarctic climate, i.e. where the water temperature was ground was also studied. An initial disturbance in the form of a horizontal groundwater flow was necessary to start the convection. Transient solutions describe the development of convective cells in the groundwater and it took 22 days before fully developed convection patterns were formed. The thermal convection reached a maximum depth of 1.0 m in soil of low permeability (2.71 · 10-9 m2). At groundwater temperature close to its density maximum (4 °C), the physical size (in m) of the convection cells was reduced. Small stones or frost lenses in the ground slightly affect the convective flow, while larger obstacles change the size and shape of the convection cells. Performed simulations show that "seasonal groundwater turnover" occurs. This knowledge may be useful in the prevention of nutrient leakage to underlying groundwater from soils, especially in agricultural areas where no natural vertical groundwater flow is evident. An application in northern Sweden is discussed.

  14. Extreme temperature and oil contamination shape the relative abundance of copepod species in the Arctic

    DEFF Research Database (Denmark)

    Dinh, Khuong Van; Nielsen, Torkel Gissel

    is of north Atlantic origin. Pyrene is one of the most toxic components of crude oil to marine copepods. The temperatures of 2, 6 and 10°C represent the mean sea water temperature, the 4°C increase in mean temperature by 2100 as predicted by IPCC scenario RCP8.5 (2013) and the extreme sea water temperature...

  15. Temperature and precipitation extremes in century-long gridded observations, reanalyses, and atmospheric model simulations

    Science.gov (United States)

    Donat, Markus G.; Alexander, Lisa V.; Herold, Nicholas; Dittus, Andrea J.

    2016-10-01

    Knowledge about long-term changes in climate extremes is vital to better understand multidecadal climate variability and long-term changes and to place today's extreme events in a historical context. While global changes in temperature and precipitation extremes since the midtwentieth century are well studied, knowledge about century-scale changes is limited. This paper analyses a range of largely independent observations-based data sets covering 1901-2010 for long-term changes and interannual variability in daily scale temperature and precipitation extremes. We compare across data sets for consistency to ascertain our confidence in century-scale changes in extremes. We find consistent warming trends in temperature extremes globally and in most land areas over the past century. For precipitation extremes we find global tendencies toward more intense rainfall throughout much of the twentieth century; however, local changes are spatially more variable. While global time series of the different data sets agree well after about 1950, they often show different changes during the first half of the twentieth century. In regions with good observational coverage, gridded observations and reanalyses agree well throughout the entire past century. Simulations with an atmospheric model suggest that ocean temperatures and sea ice may explain up to about 50% of interannual variability in the global average of temperature extremes, and about 15% in the global average of moderate precipitation extremes, but local correlations are mostly significant only in low latitudes.

  16. Improving the health forecasting alert system for cold weather and heat-waves in England: a case-study approach using temperature-mortality relationships

    Science.gov (United States)

    Masato, Giacomo; Cavany, Sean; Charlton-Perez, Andrew; Dacre, Helen; Bone, Angie; Carmicheal, Katie; Murray, Virginia; Danker, Rutger; Neal, Rob; Sarran, Christophe

    2015-04-01

    The health forecasting alert system for cold weather and heatwaves currently in use in the Cold Weather and Heatwave plans for England is based on 5 alert levels, with levels 2 and 3 dependent on a forecast or actual single temperature action trigger. Epidemiological evidence indicates that for both heat and cold, the impact on human health is gradual, with worsening impact for more extreme temperatures. The 60% risk of heat and cold forecasts used by the alerts is a rather crude probabilistic measure, which could be substantially improved thanks to the state-of-the-art forecast techniques. In this study a prototype of a new health forecasting alert system is developed, which is aligned to the approach used in the Met Office's (MO) National Severe Weather Warning Service (NSWWS). This is in order to improve information available to responders in the health and social care system by linking temperatures more directly to risks of mortality, and developing a system more coherent with other weather alerts. The prototype is compared to the current system in the Cold Weather and Heatwave plans via a case-study approach to verify its potential advantages and shortcomings. The prototype health forecasting alert system introduces an "impact vs likelihood matrix" for the health impacts of hot and cold temperatures which is similar to those used operationally for other weather hazards as part of the NSWWS. The impact axis of this matrix is based on existing epidemiological evidence, which shows an increasing relative risk of death at extremes of outdoor temperature beyond a threshold which can be identified epidemiologically. The likelihood axis is based on a probability measure associated with the temperature forecast. The new method is tested for two case studies (one during summer 2013, one during winter 2013), and compared to the performance of the current alert system. The prototype shows some clear improvements over the current alert system. It allows for a much greater

  17. An investigation of moving bed biofilm reactor nitrification during long-term exposure to cold temperatures.

    Science.gov (United States)

    Hoang, Valerie; Delatolla, Robert; Laflamme, Edith; Gadbois, Alain

    2014-01-01

    Biological treatment is the most common and economical means of ammonia removal in wastewater; however, nitrification rates can become completely impeded at cold temperatures. Attached growth processes and, specifically, moving bed biofilm reactors (MBBRs) have shown promise with respect to low-temperature nitrification. In this study, two laboratory MBBRs were used to investigate MBBR nitrification rates at 20, 5, and 1 degree C. Furthermore, the solids detached by the MBBR reactors were investigated and Arrhenius temperature correction models used to predict nitrification rates after long-term low-temperature exposure was evaluated. The nitrification rate at 5 degrees C was 66 +/- 3.9% and 64 +/- 3.7% compared to the rate measured at 20 degrees C for reactors 1 and 2, respectively. The nitrification rates at 1 degree C over a 4-month exposure period compared to the rate at 20 degrees C were 18.7 +/- 5.5% and 15.7 +/- 4.7% for the two reactors. The quantity of solids detached from the MBBR biocarriers was low and the mass of biofilm per carrier did not vary significantly at 20 degrees C compared to that after long-term exposure at 1 degree C. Lastly, a temperature correction model based on exposure time to cold temperatures showed a strong correlation to the calculated ammonia removal rates relative to 20 degrees C following a gradual acclimatization period to cold temperatures.

  18. Probabilistic models for assessment of extreme temperatures and relative humidity in Lithuania

    Science.gov (United States)

    Alzbutas, Robertas; Šeputytė, Ilona

    2015-04-01

    Extreme temperatures are fairly common natural phenomenon in Lithuania. They have mainly negative effects both on the environment and humans. Thus there are important to perform probabilistic and statistical analyzes of possibly extreme temperature values and their time-dependant changes. This is especially important in areas where technical objects (sensitive to the extreme temperatures) are foreseen to be constructed. In order to estimate the frequencies and consequences of possible extreme temperatures, the probabilistic analysis of the event occurrence and its uncertainty has been performed: statistical data have been collected and analyzed. The probabilistic analysis of extreme temperatures in Lithuanian territory is based on historical data taken from Lithuanian Hydrometeorology Service, Dūkštas Meteorological Station, Lithuanian Energy Institute and Ignalina NNP Environmental Protection Department of Environmental Monitoring Service. The main objective of performed work was the probabilistic assessment of occurrence and impact of extreme temperature and relative humidity occurring in whole Lithuania and specifically in Dūkštas region where Ignalina Nuclear Power Plant is closed for decommissioning. In addition, the other purpose of this work was to analyze the changes of extreme temperatures. The probabilistic analysis of extreme temperatures increase in Lithuanian territory was based on more than 50 years historical data. The probabilistic assessment was focused on the application and comparison of Gumbel, Weibull and Generalized Value (GEV) distributions, enabling to select a distribution, which has the best fit for data of extreme temperatures. In order to assess the likelihood of extreme temperatures different probabilistic models were applied to evaluate the probability of exeedance of different extreme temperatures. According to the statistics and the relationship between return period and probabilities of temperatures the return period for 30

  19. Scaling precipitation extremes with temperature in the Mediterranean: past climate assessment and projection in anthropogenic scenarios

    Science.gov (United States)

    Drobinski, Philippe; Silva, Nicolas Da; Panthou, Gérémy; Bastin, Sophie; Muller, Caroline; Ahrens, Bodo; Borga, Marco; Conte, Dario; Fosser, Giorgia; Giorgi, Filippo; Güttler, Ivan; Kotroni, Vassiliki; Li, Laurent; Morin, Efrat; Önol, Bariş; Quintana-Segui, Pere; Romera, Raquel; Torma, Csaba Zsolt

    2016-03-01

    In this study we investigate the scaling of precipitation extremes with temperature in the Mediterranean region by assessing against observations the present day and future regional climate simulations performed in the frame of the HyMeX and MED-CORDEX programs. Over the 1979-2008 period, despite differences in quantitative precipitation simulation across the various models, the change in precipitation extremes with respect to temperature is robust and consistent. The spatial variability of the temperature-precipitation extremes relationship displays a hook shape across the Mediterranean, with negative slope at high temperatures and a slope following Clausius-Clapeyron (CC)-scaling at low temperatures. The temperature at which the slope of the temperature-precipitation extreme relation sharply changes (or temperature break), ranges from about 20 °C in the western Mediterranean to relationship is close to CC-scaling at temperatures below the temperature break, while at high temperatures, the negative slope is close, but somewhat flatter or steeper, than in the current climate depending on the model. Overall, models predict more intense precipitation extremes in the future. Adjusting the temperature-precipitation extremes relationship in the present climate using the CC law and the temperature shift in the future allows the recovery of the temperature-precipitation extremes relationship in the future climate. This implies negligible regional changes of relative humidity in the future despite the large warming and drying over the Mediterranean. This suggests that the Mediterranean Sea is the primary source of moisture which counteracts the drying and warming impacts on relative humidity in parts of the Mediterranean region.

  20. Cold Temperature Delays Wound Healing in Postharvest Sugarbeet Roots

    Directory of Open Access Journals (Sweden)

    Karen Klotz Fugate

    2016-04-01

    Full Text Available Storage temperature affects the rate and extent of wound-healing in a number of root and tuber crops. The effect of storage temperature on wound-healing in sugarbeet (Beta vulgaris L. roots, however, is largely unknown. Wound-healing of sugarbeet roots was investigated using surface-abraded roots stored at 6 and 12 °C for 28 d. Surface abrasions are common injuries of stored roots, and the storage temperatures used are typical of freshly harvested or rapidly cooled roots. Transpiration rate from the wounded surface and root weight loss were used to quantify wound healing. At 12 °C, transpiration rate from the wounded surface declined within 14 d and wounded roots lost weight at a rate similar to unwounded controls. At 6 °C, transpiration rate from the wounded surface did not decline in the 28 d after injury, and wounded roots lost 44% more weight than controls after 28 d storage. Melanin formation, lignification, and suberization occurred more rapidly at 12 °C than at 6 °C, and a continuous layer of lignified and suberized cells developed at 12 °C, but not at 6 °C. Examination of enzyme activities involved in melanin, lignin, and suberin formation indicated that differences in melanin formation at 6 and 12 °C were related to differences in polyphenol oxidase activity, although no relationships between suberin or lignin formation and phenylalanine ammonia lyase or peroxidase activity were evident. Wound-induced respiration was initially greater at 12 °C than at 6 °C. However, with continued storage, respiration rate of wounded roots declined more rapidly at 12 °C, and over 28 d, the increase in respiration due to injury was 52% greater in roots stored at 6 °C than in roots stored at 12 °C. The data indicate that storage at 6 °C severely slowed and impaired wound-healing of surface-abraded sugarbeet roots relative to roots stored at 12 °C and suggest that postharvest losses may be accelerated if freshly harvested roots are cooled

  1. A Coupled Phase-Temperature Model for Dynamics of Transient Neuronal Signal in Mammals Cold Receptor

    Science.gov (United States)

    Kirana, Firman Ahmad; Husein, Irzaman Sulaiman

    2016-01-01

    We propose a theoretical model consisting of coupled differential equation of membrane potential phase and temperature for describing the neuronal signal in mammals cold receptor. Based on the results from previous work by Roper et al., we modified a nonstochastic phase model for cold receptor neuronal signaling dynamics in mammals. We introduce a new set of temperature adjusted functional parameters which allow saturation characteristic at high and low steady temperatures. The modified model also accommodates the transient neuronal signaling process from high to low temperature by introducing a nonlinear differential equation for the “effective temperature” changes which is coupled to the phase differential equation. This simple model can be considered as a candidate for describing qualitatively the physical mechanism of the corresponding transient process. PMID:27774102

  2. A Coupled Phase-Temperature Model for Dynamics of Transient Neuronal Signal in Mammals Cold Receptor

    Directory of Open Access Journals (Sweden)

    Firman Ahmad Kirana

    2016-01-01

    Full Text Available We propose a theoretical model consisting of coupled differential equation of membrane potential phase and temperature for describing the neuronal signal in mammals cold receptor. Based on the results from previous work by Roper et al., we modified a nonstochastic phase model for cold receptor neuronal signaling dynamics in mammals. We introduce a new set of temperature adjusted functional parameters which allow saturation characteristic at high and low steady temperatures. The modified model also accommodates the transient neuronal signaling process from high to low temperature by introducing a nonlinear differential equation for the “effective temperature” changes which is coupled to the phase differential equation. This simple model can be considered as a candidate for describing qualitatively the physical mechanism of the corresponding transient process.

  3. Effects of Urbanization on Extreme Warmest Night Temperatures During Summer near Bohai

    Institute of Scientific and Technical Information of China (English)

    李庆祥; 黄嘉佑

    2013-01-01

    Many previous studies have focused on the impacts of urbanization on regional mean temperatures. Relatively few have analyzed changes in extreme temperatures. Here, we examine the impact of urbanization on extreme warmest night temperatures from 33 stations in the Bohai area between 1958 and 2009. We compute the Generalized Extreme Value (GEV) distribution of extreme warmest night temperatures and analyze long-term variations in its characteristic parameters. A new classification method based on the factor analysis of changes in extreme night temperatures is developed to detect the effects of urbanization in different cities. Of the three parameters that characterize the GEV distribution, the position parameter is the most representative of long-term changes in extreme warmest night temperatures. During the period of rapid urbanization (i.e., after 1978), all three parameters of the GEV distribution are larger for the urban station group than for the reference station group, so are the magnitudes of their variations, and the urban areas have been experiencing higher extreme warmest night temperatures with larger variability. Different types of cities in the Bohai area have all experienced an urban heat island effect, with an average urbanization effect of approximately 0.3℃per decade.

  4. The GOCF/AWAP system - forecasting temperature extremes

    Energy Technology Data Exchange (ETDEWEB)

    Fawcett, Robert [National Climate Centre, Australian Bureau of Meteorology, Docklands, Victoria 3008 (Australia); Hume, Timothy, E-mail: r.fawcett@bom.gov.a, E-mail: t.hume@bom.gov.a [Centre for Australian Weather and Climate Research, Australian Bureau of Meteorology, Docklands, Victoria 3008 (Australia)

    2010-08-15

    Gridded hourly temperature forecasts from the Bureau of Meteorology's Gridded Operational Consensus Forecasting (GOCF) system are combined in real time with the Australian Water Availability Project (AWAP) gridded daily temperature analyses to produce gridded daily maximum and minimum temperature forecasts with lead times from one to five days. These forecasts are compared against the historical record of AWAP daily temperature analyses (1911 to present), to identify regions where record or near-record temperatures are predicted to occur. This paper describes the GOCF/AWAP system, showing how the daily maximum and minimum temperature forecasts are prepared from the hourly forecasts, and how they are bias-corrected in real time using the AWAP analyses, against which they are subsequently verified. Using monthly climatologies of long-term daily mean, standard deviation and all-time highest and lowest on record, derived forecast products (for both maximum and minimum temperature) include ordinary and standardised anomalies, 'forecast - highest on record' and 'forecast - lowest on record'. Compensation for the climatological variation across the country is achieved in these last two products, which provide the necessary guidance as to whether or not record-breaking temperatures are expected, by expressing the forecast departure from the previous record in both {sup 0}C and standard deviations.

  5. The GOCF/AWAP system - forecasting temperature extremes

    Science.gov (United States)

    Fawcett, Robert; Hume, Timothy

    2010-08-01

    Gridded hourly temperature forecasts from the Bureau of Meteorology's Gridded Operational Consensus Forecasting (GOCF) system are combined in real time with the Australian Water Availability Project (AWAP) gridded daily temperature analyses to produce gridded daily maximum and minimum temperature forecasts with lead times from one to five days. These forecasts are compared against the historical record of AWAP daily temperature analyses (1911 to present), to identify regions where record or near-record temperatures are predicted to occur. This paper describes the GOCF/AWAP system, showing how the daily maximum and minimum temperature forecasts are prepared from the hourly forecasts, and how they are bias-corrected in real time using the AWAP analyses, against which they are subsequently verified. Using monthly climatologies of long-term daily mean, standard deviation and all-time highest and lowest on record, derived forecast products (for both maximum and minimum temperature) include ordinary and standardised anomalies, "forecast - highest on record" and "forecast - lowest on record". Compensation for the climatological variation across the country is achieved in these last two products, which provide the necessary guidance as to whether or not record-breaking temperatures are expected, by expressing the forecast departure from the previous record in both °C and standard deviations.

  6. Characterization of evaporation rate, temperature, velocity and humidity fields in a cold chamber

    OpenAIRE

    LECOQ L.; Flick, D.; Plana Fattori, A.; Laguerre, O.

    2014-01-01

    3rd IIR International Conference on Sustainability and the Cold Chain, ICCC 2014, London, , 23-/06/2014 - 25/06/2014; International audience; In a food factory some pathogenic bacteria can grow even at low temperature, especially Listeria Monocytogenes which resists to temperature around 0°C. Currently, two ways are used to prevent bacterial growth; product treatment (pasteurization, pH decrease) and cleaning but it's not sufficient to eliminate all microorganisms. This work takes part of a f...

  7. Measuring and manipulating the temperature of cold molecules trapped on a chip

    CERN Document Server

    Marx, Silvio; Sartakov, Boris G; Meijer, Gerard; Santambrogio, Gabriele

    2014-01-01

    We demonstrate the measurement and manipulation of the temperature of cold CO molecules in a microchip environment. Through the use of time-resolved spatial imaging, we are able to observe the phase-space distribution of the molecules, and hence deduce the corresponding temperature. We do this both by observing the expansion of the molecular ensemble in time and through the use of numerical trajectory simulations. Furthermore, we demonstrate the adiabatic cooling of the trapped molecular sample and discuss this process.

  8. Rising sea levels will reduce extreme temperature variations in tide-dominated reef habitats

    Science.gov (United States)

    Lowe, Ryan Joseph; Pivan, Xavier; Falter, James; Symonds, Graham; Gruber, Renee

    2016-01-01

    Temperatures within shallow reefs often differ substantially from those in the surrounding ocean; therefore, predicting future patterns of thermal stresses and bleaching at the scale of reefs depends on accurately predicting reef heat budgets. We present a new framework for quantifying how tidal and solar heating cycles interact with reef morphology to control diurnal temperature extremes within shallow, tidally forced reefs. Using data from northwestern Australia, we construct a heat budget model to investigate how frequency differences between the dominant lunar semidiurnal tide and diurnal solar cycle drive ~15-day modulations in diurnal temperature extremes. The model is extended to show how reefs with tidal amplitudes comparable to their depth, relative to mean sea level, tend to experience the largest temperature extremes globally. As a consequence, we reveal how even a modest sea level rise can substantially reduce temperature extremes within tide-dominated reefs, thereby partially offsetting the local effects of future ocean warming. PMID:27540589

  9. Daily temperature extremes play an important role in predicting thermal effects.

    Science.gov (United States)

    Ma, Gang; Hoffmann, Ary A; Ma, Chun-Sen

    2015-07-01

    Organisms in natural environments experience diel temperature fluctuations, including sporadic extreme conditions, rather than constant temperatures. Studies based mainly on model organisms have tended to focus on responses to average temperatures or short-term heat stress, which overlooks the potential impact of daily fluctuations, including stressful daytime periods and milder night-time periods. Here, we focus on daily maximum temperatures, while holding night-time temperatures constant, to specifically investigate the effects of high temperature on demographic parameters and fitness in the English grain aphid Sitobion avenae. We then compared the observed effects of different daily maximum temperatures with predictions from constant temperature-performance expectations. Moderate daily maximum temperatures depressed aphid performance while extreme conditions had dramatic effects, even when mean temperatures were below the critical maximum. Predictions based on daily average temperature underestimated negative effects of temperature on performance by ignoring daily maximum temperature, while predictions based on daytime maximum temperatures overestimated detrimental impacts by ignoring recovery under mild night-time temperatures. Our findings suggest that daily maximum temperature will play an important role in regulating natural population dynamics and should be considered in predictions. These findings have implications for natural population dynamics, particularly when considering the expected increase in extreme temperature events under climate change.

  10. Contrasting responses of terrestrial ecosystem production to hot temperature extreme regimes between grassland and forest

    Directory of Open Access Journals (Sweden)

    Y. Zhang

    2014-04-01

    Full Text Available Observational data during the past several decades show faster increase of hot temperature extremes over land than changes in mean temperature. Towards more extreme temperature is expected to affect terrestrial ecosystem function. However, the ecological impacts of hot extremes on vegetation production remain uncertain across biomes in natural climatic conditions. In this study, we investigated the effects of hot temperature extremes on aboveground net primary production (ANPP by combining MODIS EVI dataset and in situ climatic records during 2000 to 2009 from 12 long-term experimental sites across biomes and climates. Our results showed that higher mean annual maximum temperatures (Tmax greatly reduced grassland production, and yet enhanced forest production after removing the effects of precipitation. Relative decreases in ANPP were 16% for arid grassland and 7% for mesic grassland, and the increase were 5% for forest. We also observed a significant positive relationship between interannual ANPP and Tmax for forest biome (R2 = 0.79, P < 0.001. This line of evidence suggests that hot temperature extreme leads to contrasting ecosystem-level response of vegetation production to warming climate between grassland and forest. Given that many terrestrial ecosystem models use average daily temperature as input, predictions of ecosystem production should consider these contrasting responses to more hot temperature extreme regimes associated with climate change.

  11. Extreme temperature sensing using brillouin scattering in optical fibers

    CERN Document Server

    Fellay, Alexandre

    Stimulated Brillouin scattering in silica-based optical fibers may be considered from two different and complementary standpoints. For a physicist, this interaction of light and pressure wave in a material, or equivalently in quantum theory terms between photons and phonons, gives some glimpses of the atomic structure of the solid and of its vibration modes. For an applied engineer, the same phenomenon may be put to good use as a sensing mechanism for distributed measurements, thanks to the dependence of the scattered light on external parameters such as the temperature, the pressure or the strain applied to the fiber. As far as temperature measurements are concerned, Brillouin-based distributed sensors have progressively gained wide recognition as efficient systems, even if their rather high cost still restricts the number of their applications. Yet they are generally used in a relatively narrow temperature range around the usual ambient temperature; in this domain, the frequency of the scattered light incre...

  12. Extreme Temperature, Rad-Hard Power Management ASIC Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Ridgetop Group will design a rad-hard Application Specific Integrated Circuit (ASIC) for spacecraft power management that is functional over a temperature range of...

  13. Electronic Modeling and Design for Extreme Temperatures Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop electronics for operation at temperatures that range from -230oC to +130oC. This new technology will minimize the requirements for external...

  14. 40 CFR 86.1864-10 - How to comply with the fleet average cold temperature NMHC standards.

    Science.gov (United States)

    2010-07-01

    ... is not an intermediate useful life standard for cold temperature NMHC standards. (c) Altitude. Altitude requirements for cold temperature NMHC standards are provided in § 86.1810-09(f). (d) Small volume... used to control emissions at high altitude conditions, and software used to control emissions or...

  15. Growth of group II Clostridium botulinum strains at extreme temperatures.

    Science.gov (United States)

    Derman, Yağmur; Lindström, Miia; Selby, Katja; Korkeala, Hannu

    2011-11-01

    The minimum and maximum growth temperatures and the maximum growth rates at 10, 30, 37, and 40°C were determined for 24 group II Clostridium botulinum strains. Genetic diversity of the strains was revealed by amplified fragment length polymorphism (AFLP) analysis. The minimum growth temperatures ranged from 6.2 to 8.6°C, and the maximum growth temperatures ranged from 34.7 to 39.9°C. The mean maximum growth temperatures and mean maximum growth rates of type E strains at 37°C were significantly higher than those of type B and type F strains. A significant correlation between maximum growth rates at 37°C and maximum growth temperatures was found for all strains. Some type E strains with a high minimum growth temperature also had a higher maximum growth rate at 37°C than at 30°C, which suggests that some group II C. botulinum strains are more mesophilic in their growth properties than others. We found relatively small differences between AFLP clusters, indicating that diverse genetic background among the strains was not reflected in the growth properties. The growth characteristics of group II C. botulinum and some type E strains with mesophilic growth properties may have an impact on inoculation studies and predictive modeling for assessing the safety of foods.

  16. Sensitivity of cold acclimation to elevated autumn temperature in field-grown Pinus strobus seedlings

    Directory of Open Access Journals (Sweden)

    Christine Yao-Yun Chang

    2015-03-01

    Full Text Available Climate change will increase autumn air temperature, while photoperiod decrease will remain unaffected. We assessed the effect of increased autumn air temperature on timing and development of cold acclimation and freezing resistance in Eastern white pine (EWP, Pinus strobus under field conditions. For this purpose we simulated projected warmer temperatures for southern Ontario in a Temperature Free-Air-Controlled Enhancement (T-FACE experiment and exposed EWP seedlings to ambient (Control or elevated temperature (ET, +1.5°C/+3°C during day/night. Photosynthetic gas exchange, chlorophyll fluorescence, photoprotective pigments, leaf non-structural carbohydrates (NSC, and cold hardiness were assessed over two consecutive autumns. Nighttime temperature below 10°C and photoperiod below 12h initiated downregulation of assimilation in both treatments. When temperature further decreased to 0°C and photoperiod became shorter than 10h, downregulation of the light reactions and upregulation of photoprotective mechanisms occurred in both treatments. While ET seedlings did not delay the timing of the downregulation of assimilation, stomatal conductance in ET seedlings was decreased by 20-30% between August and early October. In both treatments leaf NSC composition changed considerably during autumn but differences between Control and ET seedlings were not significant. Similarly, development of freezing resistance was induced by exposure to low temperature during autumn, but the timing was not delayed in ET seedlings compared to Control seedlings. Our results indicate that EWP is most sensitive to temperature changes during October and November when downregulation of photosynthesis , enhancement of photoprotection, synthesis of cold-associated NSCs and development of freezing resistance occur. However, we also conclude that the timing of the development of freezing resistance in EWP seedlings is not affected by moderate temperature increases used in our

  17. Variability and long-term change in Australian temperature and precipitation extremes

    Directory of Open Access Journals (Sweden)

    Dörte Jakob

    2016-12-01

    We conclude that in assessing the likelihood of climate hazards, one needs to consider the modulation of climate extremes due to both long-term change and climate variability. Our findings imply that when planning for adaptation, different emphasis needs to be given to changing temperature and precipitation extremes.

  18. Changing Temperature and Precipitation Extremes in Europe's Climate of the 20th Century

    NARCIS (Netherlands)

    Klein Tank, Albertus Maria Gerardus

    2004-01-01

    This thesis aims at increasing the knowledge on past changes in extremes through the analysis of historical records of observations at meteorological stations. The key question addressed is: How did the extremes of daily surface air temperature and precipitation change in Europe's climate of the

  19. Adaptation potential of naturally ventilated barns to high temperature extremes: The OptiBarn project

    Science.gov (United States)

    Menz, Christoph

    2016-04-01

    Climate change interferes with various aspects of the socio-economic system. One important aspect is its influence on animal husbandry, especially dairy faming. Dairy cows are usually kept in naturally ventilated barns (NVBs) which are particular vulnerable to extreme events due to their low adaptation capabilities. An effective adaptation to high outdoor temperatures for example, is only possible under certain wind and humidity conditions. High temperature extremes are expected to increase in number and strength under climate change. To assess the impact of this change on NVBs and dairy cows also the changes in wind and humidity needs to be considered. Hence we need to consider the multivariate structure of future temperature extremes. The OptiBarn project aims to develop sustainable adaptation strategies for dairy housings under climate change for Europe, by considering the multivariate structure of high temperature extremes. In a first step we identify various multivariate high temperature extremes for three core regions in Europe. With respect to dairy cows in NVBs we will focus on the wind and humidity field during high temperature events. In a second step we will use the CORDEX-EUR-11 ensemble to evaluate the capability of the RCMs to model such events and assess their future change potential. By transferring the outdoor conditions to indoor climate and animal wellbeing the results of this assessment can be used to develop technical, architectural and animal specific adaptation strategies for high temperature extremes.

  20. Numerical simulation and experimental study of the submarine's cold wake temperature character

    Science.gov (United States)

    Chen, Shengtao; Zhong, Jingjun; Sun, Peng

    2014-06-01

    The temperature difference of the submarine's wake on the sea surface is the base for the IR detection. In this paper, the temperature difference on the sea surface caused by the submarine's propellers and the submarine's hull is studied by solving the three dimensional N-S equations. The results show that under the condition of sea temperature surroundings of minus gradient, such as in summer the upper water's temperature is higher than the lower water, it is cold wake on the sea surface and hot wake on the submarine's plane. The temperature difference between the wake and the water around in the wake's initial part becomes more and more obvious as the wake's distance gets longer. Through the IR camera, the submarine's propeller wake is studied under the same temperature status. Obvious IR temperature difference signals can be observed and it is consistent with the numerical simulation for the submarine.

  1. The nonstationary impact of local temperature changes and ENSO on extreme precipitation at the global scale

    Science.gov (United States)

    Sun, Qiaohong; Miao, Chiyuan; Qiao, Yuanyuan; Duan, Qingyun

    2017-02-01

    The El Niño-Southern Oscillation (ENSO) and local temperature are important drivers of extreme precipitation. Understanding the impact of ENSO and temperature on the risk of extreme precipitation over global land will provide a foundation for risk assessment and climate-adaptive design of infrastructure in a changing climate. In this study, nonstationary generalized extreme value distributions were used to model extreme precipitation over global land for the period 1979-2015, with ENSO indicator and temperature as covariates. Risk factors were estimated to quantify the contrast between the influence of different ENSO phases and temperature. The results show that extreme precipitation is dominated by ENSO over 22% of global land and by temperature over 26% of global land. With a warming climate, the risk of high-intensity daily extreme precipitation increases at high latitudes but decreases in tropical regions. For ENSO, large parts of North America, southern South America, and southeastern and northeastern China are shown to suffer greater risk in El Niño years, with more than double the chance of intense extreme precipitation in El Niño years compared with La Niña years. Moreover, regions with more intense precipitation are more sensitive to ENSO. Global climate models were used to investigate the changing relationship between extreme precipitation and the covariates. The risk of extreme, high-intensity precipitation increases across high latitudes of the Northern Hemisphere but decreases in middle and lower latitudes under a warming climate scenario, and will likely trigger increases in severe flooding and droughts across the globe. However, there is some uncertainties associated with the influence of ENSO on predictions of future extreme precipitation, with the spatial extent and risk varying among the different models.

  2. Some like it hot, some like it cold: Temperature dependent biotechnological applications and improvements in extremophilic enzymes.

    Science.gov (United States)

    Siddiqui, Khawar Sohail

    2015-12-01

    The full biotechnological exploitation of enzymes is still hampered by their low activity, low stability and high cost. Temperature-dependent catalytic properties of enzymes are a key to efficient and cost-effective translation to commercial applications. Organisms adapted to temperature extremes are a rich source of enzymes with broad ranging thermal properties which, if isolated, characterized and their structure-function-stability relationship elucidated, could underpin a variety of technologies. Enzymes from thermally-adapted organisms such as psychrophiles (low-temperature) and thermophiles (high-temperature) are a vast natural resource that is already under scrutiny for their biotechnological potential. However, psychrophilic and thermophilic enzymes show an activity-stability trade-off that necessitates the use of various genetic and chemical modifications to further improve their properties to suit various industrial applications. This review describes in detail the properties and biotechnological applications of both cold-adapted and thermophilic enzymes. Furthermore, the review critically examines ways to improve their value for biotechnology, concluding by proposing an integrated approach involving thermally-adapted, genetically and magnetically modified enzymes to make biocatalysis more efficient and cost-effective.

  3. Cold pressor stimulus temperature and resting masseter muscle haemodynamics in normal humans.

    Science.gov (United States)

    Maekawa, K; Kuboki, T; Clark, G T; Shinoda, M; Yamashita, A

    1998-11-01

    Cold pressor stimulation reportedly increases sympathetic nerve activity in human skeletal muscles. This study examined the effect of cold pressor stimulation on the resting haemodynamics of the right masseter muscle in normal individuals, using near-infrared spectroscopy. Nine healthy non-smoking males with no history of chronic muscle pain or vascular headaches participated. Their right hand was immersed in a water bath (4, 10, 15 degrees C) for exactly 1 min. Each trial lasted 7 min (1 min before, 1 min during, 5 min after stimulation) and a strictly random order was utilized for the three test temperatures and the mock trial. Masseter muscle haemoglobin concentration and oxygen saturation, as well as heart rate and blood pressure, were continuously recorded in each trial. After completing the four trials, each participant produced and sustained a 30-s maximum voluntary clench in the intercuspal position. Data across the four trials were baseline-corrected and then magnitude-normalized to the individual's highest absolute haemoglobin and oxygen signal during the 30-s maximal clenching effort. Haemoglobin and oxygen saturation increased progressively during cold pressor stimulation as the water temperature decreased (Hb, p cold pressor, stimulation induces a strong increase in intramuscular blood volume which appears to be due to both a local vasodilative response and increased cardiac output.

  4. Solid Nitrogen at Extreme Conditions of High Pressure and Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Goncharov, A; Gregoryanz, E

    2004-04-05

    We review the phase diagram of nitrogen in a wide pressure and temperature range. Recent optical and x-ray diffraction studies at pressures up to 300 GPa and temperatures in excess of 1000 K have provided a wealth of information on the transformation of molecular nitrogen to a nonmolecular (polymeric) semiconducting and two new molecular phases. These newly found phases have very large stability (metastability) range. Moreover, two new molecular phases have considerably different orientational order from the previously known phases. In the iota phase (unlike most of other known molecular phases), N{sub 2} molecules are orientationally equivalent. The nitrogen molecules in the theta phase might be associated into larger aggregates, which is in line with theoretical predictions on polyatomic nitrogen.

  5. Telemetry pill versus rectal and esophageal temperature during extreme rates of exercise-induced core temperature change

    NARCIS (Netherlands)

    Teunissen, L.P.J.; Haan, A. de; Koning, J.J. de; Daanen, H.A.M.

    2012-01-01

    Core temperature measurement with an ingestible telemetry pill has been scarcely investigated during extreme rates of temperature change, induced by short high-intensity exercise in the heat. Therefore, nine participants performed a protocol of rest, (sub)maximal cycling and recovery at 30 °C. The p

  6. Cold wire constant voltage anemometry to measure temperature fluctuations and its application in a thermoacoustic system

    Science.gov (United States)

    Cleve, Sarah; Jondeau, Emmanuel; Blanc-Benon, Philippe; Comte-Bellot, Geneviève

    2017-04-01

    The knowledge of temperature fluctuations is essential for most thermoacoustic systems. In the present paper, cold wire constant-voltage anemometry (CVA) to measure temperature fluctuations is presented. Corrections for the thermal inertia and for the end losses of the wire are applied during the post-processing. The correction for the thermal inertia of the cold wire is achieved by applying a time dependent thermal lag as proposed originally for a constant-current anemometry (CCA) system. This thermal lag is measured in parallel by a hot wire. The thermal end losses of the wires to their supports are also considered and approximate corrections are proposed. The procedure for the cold wire CVA is validated in the acoustic field of an acoustic resonator with wires of different lengths. A comparison between a CVA and a CCA measurement also confirms the CVA measurement. Furthermore, the proposed measurement procedure is applied close to the stack of a thermoacoustic refrigerator. Supposing a two-dimensional flow, the simultaneous measurement of velocity and temperature fluctuations is possible. This allows a detailed examination of the acoustic field close to the stack, including the study of the correlation between temperature and velocity.

  7. Understanding the surface temperature cold bias in CMIP5 AGCMs over the Tibetan Plateau

    Science.gov (United States)

    Chen, X.; Liu, Y.; Wu, G. X.

    2016-12-01

    Recent studies have demonstrated that the majority of the Phase-5 Coupled Model Inter-comparison Project (CMIP5) models underestimate annual and seasonal mean surface air temperatures (Ta) over the Tibetan Plateau (TP). In addition, half of the models underestimate annual and seasonal mean surface temperatures (Ts) over the TP. These cold biases are larger over the western TP. By decomposing the Ts bias using the surface energy budget equation, this study investigates the contributions to the cold surface temperature bias on the Tibetan Plateau from various factors, including the surface albedo-induced bias (SAF), surface cloud radiative forcing (CRF), clear-sky shortwave (SW) radiation, downward clear-sky longwave radiation (DLR), surface sensible heat flux and latent heat flux, and heat storage. The results suggest that SAF and DLR are the main factors causing the cold surface temperature bias. Because SAF and DLR are respectively affected by the snow coverage fraction and water vapor distribution produced by the models, these results then imply that the snow coverage fraction parameterization and water vapor distribution over the TP require further improvements.

  8. Sudden cold temperature regulates the time-lag between plant CO2 uptake and release

    Science.gov (United States)

    Barthel, M.; Cieraad, E.; Zakharova, A.; Hunt, J. E.

    2013-11-01

    Since substrates for respiration are supplied mainly by recent photo-assimilates, there is a strong but time-lagged link between short-term above- and belowground carbon (C) cycling. However, regulation of this coupling by environmental variables is poorly understood. Whereas recent studies focussed on the effect of drought and shading on the link between above and belowground short-term C cycling, the effect of temperature remains unclear. We used a 13CO2 pulse-chase labelling experiment to investigate the effect of a sudden temperature change from 25 °C to 10 °C on the short-term coupling between assimilatory C uptake and respiratory loss. The study was done in the laboratory using two month old perennial rye-grass plants (Cold temperature (10 °C) reduced the short-term coupling between shoot and roots by delaying belowground transfer of recent assimilates and its subsequent respiratory use, as indicated by the δ13C signal of root respiration (δ13CRR). That is, the time-lag from the actual shoot labelling to the first appearance of the label in 13CRR was about 1.5 times longer under cold temperature (time-lags of 1 h and 1.5 h in the warm and cold treatments, respectively). Moreover, analysis of bulk shoot and root material revealed that plants at cold temperature invest relatively more carbon into respiration compared to growth or storage. These results increase our understanding of environmental controls on the link between short-term above- and belowground C cycling.

  9. Corresponding Relation between Warm Season Precipitation Extremes and Surface Air Temperature in South China

    Institute of Scientific and Technical Information of China (English)

    SUN; Wei; LI; Jian; YU; Ru-Cong

    2013-01-01

    Hourly data of 42 rain gauges over South China during 1966–2005 were used to analyze the corresponding relation between precipitation extremes and surface air temperature in the warm season(May to October).The results show that below 25℃,both daily and hourly precipitation extremes in South China increase with rising temperature.More extreme events transit to the two-time Clausius-Clapeyron(CC)relationship at lower temperatures.Daily as well as hourly precipitation extremes have a decreasing tendency nearly above 25℃,among which the decrease of hourly extremes is much more significant.In order to investigate the efects of rainfall durations,hourly precipitation extremes are presented by short duration and long duration precipitation,respectively.Results show that the dramatic decrease of hourly rainfall intensities above 25℃ is mainly caused by short duration precipitation,and long duration precipitation extremes rarely occur in South China when surface air temperature surpasses 28℃.

  10. Changes of the Temperature and Precipitation Extremes on Homogenized Data

    Directory of Open Access Journals (Sweden)

    LAKATOS, Mónika

    2007-01-01

    Full Text Available Climate indices to detect changes have been defined in several international projects onclimate change. Climate index calculations require at least daily resolution of time series withoutinhomogeneities, such as transfer of stations, changes in observation practice. In many cases thecharacteristics of the estimated linear trends, calculated from the original and from the homogenizedtime series are significantly different. The ECA&D (European Climate Assessment & Dataset indicesand some other special temperature and precipitation indices of own development were applied to theClimate Database of the Hungarian Meteorological Service. Long term daily maximum, minimum anddaily mean temperature data series and daily precipitation sums were examined. The climate indexcalculation processes were tested on original observations and on homogenized daily data fortemperature; in the case of precipitation a complementation process was performed to fill in the gapsof missing data. Experiences of comparing the climate index calculation results, based on original andcomplemented-homogenized data, are reported in this paper. We present the preliminary result ofclimate index calculations also on gridded (interpolated daily data.

  11. Closed cycle cryocooler for low temperature electronics circuits: Cold end test

    Science.gov (United States)

    Pirtle, F. W.

    1983-08-01

    A fabricated MACOR cold end including a metallic coating to prevent helium permeation and a fabricated die post displacer support bearing were combined with a compressor and motor which are standard CTI-CRYOGENICS products. A mechanical test was performed on the test cryocooler to determine that the mechanical test was performed on the test cryocooler to determine that the MACOR displacer was successfully guided by the die post bearing. Thermodynamic tests were conducted to determine the lowest temperature of the 4th (coldest) stage as a function of operating speed, helium charge pressure, 4th stage electrical heat load, and transfer tube diameter. Cooldown and steady state results are reported. Results indicate a low temperature limit of approximately 95K with the current test hardware. Although this represents an improvement from 122K during the program, a resizing will be necessary to reach 10K. The die post displacer support bearing and the MACOR cold finger construction are mechanically satisfactory.

  12. Cold Shock Proteins Are Expressed in the Retina Following Exposure to Low Temperatures

    Science.gov (United States)

    Contartese, Daniela S.; Rolón, Federico; Sarotto, Anibal; Dorfman, Veronica B.; Loidl, Cesar F.; Martínez, Alfredo

    2016-01-01

    Hypothermia has been proposed as a therapeutic intervention for some retinal conditions, including ischemic insults. Cold exposure elevates expression of cold-shock proteins (CSP), including RNA-binding motif protein 3 (RBM3) and cold inducible RNA-binding protein (CIRP), but their presence in mammalian retina is so far unknown. Here we show the effects of hypothermia on the expression of these CSPs in retina-derived cell lines and in the retina of newborn and adult rats. Two cell lines of retinal origin, R28 and mRPE, were exposed to 32°C for different time periods and CSP expression was measured by qRT-PCR and Western blotting. Neonatal and adult Sprague-Dawley rats were exposed to a cold environment (8°C) and expression of CSPs in their retinas was studied by Western blotting, multiple inmunofluorescence, and confocal microscopy. RBM3 expression was upregulated by cold in both R28 and mRPE cells in a time-dependent fashion. On the other hand, CIRP was upregulated in R28 cells but not in mRPE. In vivo, expression of CSPs was negligible in the retina of newborn and adult rats kept at room temperature (24°C). Exposure to a cold environment elicited a strong expression of both proteins, especially in retinal pigment epithelium cells, photoreceptors, bipolar, amacrine and horizontal cells, Müller cells, and ganglion cells. In conclusion, CSP expression rapidly rises in the mammalian retina following exposure to hypothermia in a cell type-specific pattern. This observation may be at the basis of the molecular mechanism by which hypothermia exerts its therapeutic effects in the retina. PMID:27556928

  13. Climate extremes in the Pacific: improving seasonal prediction of tropical cyclones and extreme ocean temperatures to improve resilience

    Science.gov (United States)

    Kuleshov, Y.; Jones, D.; Spillman, C. M.

    2012-04-01

    Climate change and climate extremes have a major impact on Australia and Pacific Island countries. Of particular concern are tropical cyclones and extreme ocean temperatures, the first being the most destructive events for terrestrial systems, while the latter has the potential to devastate ocean ecosystems through coral bleaching. As a practical response to climate change, under the Pacific-Australia Climate Change Science and Adaptation Planning program (PACCSAP), we are developing enhanced web-based information tools for providing seasonal forecasts for climatic extremes in the Western Pacific. Tropical cyclones are the most destructive weather systems that impact on coastal areas. Interannual variability in the intensity and distribution of tropical cyclones is large, and presently greater than any trends that are ascribable to climate change. In the warming environment, predicting tropical cyclone occurrence based on historical relationships, with predictors such as sea surface temperatures (SSTs) now frequently lying outside of the range of past variability meaning that it is not possible to find historical analogues for the seasonal conditions often faced by Pacific countries. Elevated SSTs are the primary trigger for mass coral bleaching events, which can lead to widespread damage and mortality on reef systems. Degraded coral reefs present many problems, including long-term loss of tourism and potential loss or degradation of fisheries. The monitoring and prediction of thermal stress events enables the support of a range of adaptive and management activities that could improve reef resilience to extreme conditions. Using the climate model POAMA (Predictive Ocean-Atmosphere Model for Australia), we aim to improve accuracy of seasonal forecasts of tropical cyclone activity and extreme SSTs for the regions of Western Pacific. Improved knowledge of extreme climatic events, with the assistance of tailored forecast tools, will help enhance the resilience and

  14. Qualification of Bonding Process of Temperature Sensors to Extreme Temperature Deep Space Missions

    Science.gov (United States)

    Ramesham, Rajeshuni; Kitiyakara, Amarit; Redick, Richard; Sunada, Eric T.

    2011-01-01

    A process has been explored based on the state-of-the-art technology to bond the platinum resistance thermometer (PRT) on to potential aerospace material such as a flat aluminum surface and a flexible copper tube to simulate coaxial cable for the flight applications. Primarily, PRTs were inserted into a metal plated copper braid to avoid stresses on the sensor while attaching the sensor with braid to the base material for long duration deep space missions. Appropriate pretreatment has been implemented in this study to enhance the adhesion of the PRTs to the base material. NuSil product has been chosen in this research to attach PRT to the base materials. The resistance (approx.1.1 k(Omega)) of PRTs has been electrically monitored continuously during the qualification thermal cycling testing from -150 C to +120 C and -100 C to -35 C. The test hardware has been thermal cycled three times the mission life per JPL design principles for JUNO project. No PRT failures were observed during and after the PRT thermal cycling qualification test for extreme temperature environments. However, there were some failures associated with staking of the PRT pig tails as a result of thermal cycling qualification test.

  15. Miniaturized implantable sensors for in vivo localized temperature measurements in mice during cold exposure.

    Science.gov (United States)

    Padovani, R; Lehnert, T; Cettour-Rose, P; Doenlen, R; Auwerx, J; Gijs, M A M

    2016-02-01

    We report on in vivo temperature measurements performed in mice at two specific sites of interest in the animal body over a period of several hours. In particular, the aim of this work was to monitor mouse metabolism during cold exposure, and to record possible temperature differences between the body temperature measured in the abdomen and the temperature of the brown adipose tissue (BAT) situated in the interscapular area. This approach is of biological interest as it may help unravelling the question whether biochemical activation of BAT is associated with local increase in metabolic heat production. For that purpose, miniaturized thermistor sensors have been accurately calibrated and implanted in the BAT and in the abdominal tissue of mice. After 1 week of recovery from surgery, mice were exposed to cold (6 °C) for a maximum duration of 6 h and the temperature was acquired continuously from the two sensors. Control measurements with a conventional rectal probe confirmed good performance of both sensors. Moreover, two different mouse phenotypes could be identified, distinguishable in terms of their metabolic resistance to cold exposure. This difference was analyzed from the thermal point of view by computational simulations. Our simple physical model of the mouse body allowed to reproduce the global evolution of hypothermia and also to explain qualitatively the temperature difference between abdomen and BAT locations. While with our approach, we have demonstrated the importance and feasibility of localized temperature measurements on mice, further optimization of this technique may help better identify local metabolism variations.

  16. Structural Adaptation of Microorganisms For Survival In Extreme Terrestrial Cold Environments

    Science.gov (United States)

    Soina, V.

    Study of viability and diversity of microorganisms in subterranean permafrost sediments showed a high colonization of various groups of microorganisms in such biotopes. Results obtained by TEM and SEM methods demonstrate a successful preservation of cell structures both in situ and under freezing and thawing of isolated strains in model experiments. Study of microstructure of permafrost samples defined that bacterial strains, isolated from permafrost, are protected against mechanical damage by ice crystals by a gel-like sheath in which they are lying. The results obtained in model experiments revealed cell differentiation into various cell types under temperature fluctuations. Such cell types preserve high viability and were similar to the forms of microorganisms viewed by TEM methods in situ. Cytological aspects of structural stability of different types of microbial cells solated from permafrost sediments in respect to exobiology is discussed.

  17. Effects of land cover change on temperature and rainfall extremes in multi-model ensemble simulations

    Directory of Open Access Journals (Sweden)

    A. J. Pitman

    2012-11-01

    Full Text Available The impact of historical land use induced land cover change (LULCC on regional-scale climate extremes is examined using four climate models within the Land Use and Climate, IDentification of robust impacts project. To assess those impacts, multiple indices based on daily maximum and minimum temperatures and daily precipitation were used. We contrast the impact of LULCC on extremes with the impact of an increase in atmospheric CO2 from 280 ppmv to 375 ppmv. In general, consistent changes in both high and low temperature extremes are similar to the simulated change in mean temperature caused by LULCC and are restricted to regions of intense modification. The impact of LULCC on both means and on most temperature extremes is statistically significant. While the magnitude of the LULCC-induced change in the extremes can be of similar magnitude to the response to the change in CO2, the impacts of LULCC are much more geographically isolated. For most models, the impacts of LULCC oppose the impact of the increase in CO2 except for one model where the CO2-caused changes in the extremes are amplified. While we find some evidence that individual models respond consistently to LULCC in the simulation of changes in rainfall and rainfall extremes, LULCC's role in affecting rainfall is much less clear and less commonly statistically significant, with the exception of a consistent impact over South East Asia. Since the simulated response of mean and extreme temperatures to LULCC is relatively large, we conclude that unless this forcing is included, we risk erroneous conclusions regarding the drivers of temperature changes over regions of intense LULCC.

  18. The limits of drought-induced rapid cold-hardening: extremely brief, mild desiccation triggers enhanced freeze-tolerance in Eurosta solidaginis larvae.

    Science.gov (United States)

    Gantz, J D; Lee, Richard E

    2015-02-01

    Rapid cold-hardening (RCH) is a highly conserved response in insects that induces physiological changes within minutes to hours of exposure to low temperature and provides protection from chilling injury. Recently, a similar response, termed drought-induced RCH, was described following as little as 6h of desiccation, producing a loss of less than 10% of fresh mass. In this study, we investigated the limits and mechanisms of this response in larvae of the goldenrod gall fly Eurosta solidaginis (Diptera, Tephritidae). The cold-hardiness of larvae increased markedly after as few as 2h of desiccation and a loss of less than 1% fresh mass, as organismal survival increased from 8% to 41% following exposure to -18 °C. Tissue-level effects of desiccation were observed within 1h, as 87% of midgut cells from desiccated larvae remained viable following freezing compared to 57% of controls. We also demonstrated that drought-induced RCH occurs independently of neuroendocrine input, as midgut tissue desiccated ex vivo displayed improved freeze-tolerance relative to control tissue (78-11% survival, respectively). Finally, though there was an increase in hemolymph osmolality beyond the expected effects of the osmo-concentration of solutes during dehydration, we determined that this increase was not due to the synthesis of glycerol, glucose, sorbitol, or trehalose. Our results indicate that E. solidaginis larvae are extremely sensitive to desiccation, which is a triggering mechanism for one or more physiological pathways that confer enhanced freeze-tolerance. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Toxin production and growth of pathogens subjected to temperature fluctuations simulating consumer handling of cold cuts.

    Science.gov (United States)

    Røssvoll, Elin; Rønning, Helene Thorsen; Granum, Per Einar; Møretrø, Trond; Hjerpekjøn, Marianne Røine; Langsrud, Solveig

    2014-08-18

    It is crucial for the quality and safety of ready-to-eat (RTE) foods to maintain the cold chain from production to consumption. The effect of temperature abuse related to daily meals and elevated refrigerator temperatures on the growth and toxin production of Bacillus cereus, Bacillus weihenstephanensis and Staphylococcus aureus and the growth of Listeria monocytogenes and Yersinia enterocolitica was studied. A case study with temperature loggings in the domestic environment during Easter and Christmas holidays was performed to select relevant time and temperature courses. A model for bacterial surface growth on food using nutrient agar plates exposed to variations in temperatures was used to simulate food stored at different temperatures and exposed to room temperature for short periods of time. The results were compared with predicted growth using the modeling tool ComBase Predictor. The consumers exposed their cold cuts to room temperatures as high as 26.5°C with an average duration of meals was 47 min daily for breakfast/brunch during the vacations. Short (≤ 2 h) daily intervals at 25°C nearly halved the time the different pathogens needed to reach levels corresponding to the levels associated with human infection or intoxication, compared with the controls continuously stored at refrigerator temperature. Although the temperature fluctuations affected growth of both B. weihenstephanensis and S. aureus, toxin production was only detected at much higher cell concentrations than what has been associated with human intoxications. Therefore, growth of L. monocytogenes and Y. enterocolitica was found to be the limiting factor for safety. In combination with data on temperature abuse in the domestic environment, modeling programs such as ComBase Predictor can be efficient tools to predict growth of some pathogens but will not predict toxin production. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Regulated and nonregulated diesel and gasoline cold start emissions at different temperatures

    Science.gov (United States)

    Weilenmann, Martin; Soltic, Patrik; Saxer, Christian; Forss, Anna-Maria; Heeb, Norbert

    The emissions of modern cars are usually reduced in warm engine conditions by catalysts. Consequently emissions are significantly higher during the cold start, i.e. the warm-up phase of the car. The duration of this period and the emissions produced during it depend on the ambient temperature as well as on the initial temperature of the car's systems. The cold start emissions of Euro-3 gasoline cars, Euro-2 diesel cars and old pre-Euro-1 gasoline cars were investigated at cold ambient temperatures. Since the goal was to get real-world emissions, the measurements were done with cars belonging to private owners taken straight from the road with no maintenance. The chassis dynamometer tests were carried out at +23, -7 and -20 °C. The test cycle employed is a representative urban ride from a real-world driving behaviour study. Besides the regulated pollutants, methane, benzene and toluene were also measured online by chemical ionisation mass spectrometry.

  1. A Calorimeter for Measurements of Multilayer Insulation at Variable Cold Temperature

    Science.gov (United States)

    Funke, Thomas; Haberstroh, Christoph

    An improved calorimeter cryostat for MLI thermal performance measurements has been designed and put into operation at the TU Dresden. Based on a liquid helium cooled flow cryostat, it allows the setting of any cold level temperature between approx. 30 K and ambient temperature. Thermal shields and all-embracing radiation guards at both ends can be kept at nearly identical temperature. This is done by means of two separate cooling circuits. Both the actual cold test surface temperature and the cooling of the mechanical support and radiation shields can be independently controlled. Insulation specimens are wrapped around a test cylinder with a surface of 0.9 m2. The heat transfer through the MLI is measured by recording the mass flow and the inlet and outlet temperature of the cooling fluid. Measurements both in horizontal and vertical orientation can be performed or compared, respectively. Moreover the effect of an additional vacuum degradation as it might occur by decreasing getter material performance in real systems at elevated temperatures can be studied by controlled inlet of an elective gas. It is reported about the design and the equipment of this cryostat and measurements of a 10 layer MLI specimen.

  2. Qualification Testing of Engineering Camera and Platinum Resistance Thermometer (PRT) Sensors for Mars Science Laboratory (MSL) Project under Extreme Temperatures to Assess Reliability and to Enhance Mission Assurance

    Science.gov (United States)

    Ramesham, Rajeshuni; Maki, Justin N.; Cucullu, Gordon C.

    2008-01-01

    Package Qualification and Verification (PQV) of advanced electronic packaging and interconnect technologies and various other types of qualification hardware for the Mars Exploration Rover/Mars Science Laboratory flight projects has been performed to enhance the mission assurance. The qualification of hardware (Engineering Camera and Platinum Resistance Thermometer, PRT) under extreme cold temperatures has been performed with reference to various project requirements. The flight-like packages, sensors, and subassemblies have been selected for the study to survive three times (3x) the total number of expected temperature cycles resulting from all environmental and operational exposures occurring over the life of the flight hardware including all relevant manufacturing, ground operations and mission phases. Qualification has been performed by subjecting above flight-like qual hardware to the environmental temperature extremes and assessing any structural failures or degradation in electrical performance due to either overstress or thermal cycle fatigue. Experiments of flight like hardware qualification test results have been described in this paper.

  3. Cold-start emissions of modern passenger cars at different low ambient temperatures and their evolution over vehicle legislation categories

    Science.gov (United States)

    Weilenmann, Martin; Favez, Jean-Yves; Alvarez, Robert

    The emissions of modern gasoline and diesel passenger cars are reduced by catalysts except in cold-starting. Since catalysts require a certain temperature (typically above 300 °C) to work to full efficiency, emissions are significantly higher during the warm-up phase of the car. The duration of this period and the emissions produced depend on the ambient temperature as well as on the initial temperature of the car's propulsion systems. The additional emissions during a warm-up phase, known as "cold-start extra emissions" (CSEEs) for emission inventory modelling, are mostly assessed by emission measurements at an ambient temperature of 23 °C. However, in many European countries average ambient temperatures are below 23 °C. This necessitates emission measurements at lower temperatures in order to model and assess cold-start emissions for real-world temperature conditions. This paper investigates the influence of regulated pollutants and CO 2 emissions of recent gasoline and diesel car models (Euro-4 legislation) at different ambient temperatures, 23, -7 and -20 °C. We present a survey and model of the evolution of cold-start emissions as a function of different car generations (pre-Euro-1 to Euro-4 legislations). In addition the contribution of CSEEs to total fleet running emissions is shown to highlight their increasing importance. For gasoline cars, it turns out that in average real-world driving the majority of the CO (carbon monoxide) and HC (hydrocarbon) total emissions are due to cold-start extra emissions. Moreover, the cold-start emissions increase considerably at lower ambient temperatures. In contrast, cold-start emissions of diesel cars are significantly lower than those of gasoline cars. Furthermore, the transition from Euro-3 to Euro-4 gasoline vehicles shows a trend for a smaller decline for cold-start extra emissions than for legislative limits. Particle and NO x emission of cold-starts are less significant.

  4. Technical Note: Bias correcting climate model simulated daily temperature extremes with quantile mapping

    Directory of Open Access Journals (Sweden)

    B. Thrasher

    2012-09-01

    Full Text Available When applying a quantile mapping-based bias correction to daily temperature extremes simulated by a global climate model (GCM, the transformed values of maximum and minimum temperatures are changed, and the diurnal temperature range (DTR can become physically unrealistic. While causes are not thoroughly explored, there is a strong relationship between GCM biases in snow albedo feedback during snowmelt and bias correction resulting in unrealistic DTR values. We propose a technique to bias correct DTR, based on comparing observations and GCM historic simulations, and combine that with either bias correcting daily maximum temperatures and calculating daily minimum temperatures or vice versa. By basing the bias correction on a base period of 1961–1980 and validating it during a test period of 1981–1999, we show that bias correcting DTR and maximum daily temperature can produce more accurate estimations of daily temperature extremes while avoiding the pathological cases of unrealistic DTR values.

  5. Study on the extremely cold winter of 1670 over the middle and lower reaches of the Yangtze River

    Institute of Scientific and Technical Information of China (English)

    JunHui Yan; MingQi Li; HaoLong Liu; JingYun Zheng; Hui Fu

    2014-01-01

    The snow-cover days over the middle and lower reaches of the Yangtze River (MLRYR) in the winter of 1670 were extracted from Chinese historical documents. By these records, the winter temperature anomalies (compared to the mean of 1961-1990) recorded at seven meteorological stations and the regional mean winter temperature were estimated. The results show that:(1) There was an average of about 30 snow-cover days over the MLRYR region in 1670, ranging from 11-20 days in Shanghai and eastern Zhejiang to 51-60 days in eastern Hunan Province. The snow-cover days averaged about 40 days in Anqing and Nan-cheng, and ranged from 30 to 40 days in Quzhou, Jingdezhen, and Nanchang;and (2) the regional mean winter temperature in 1670 was estimated to be approximately 4.0 °C lower than that of 1961-1990. The maximum negative anomaly of 5.6 °C oc-curred in Nanchang and the minimum anomaly of-2.8 °C was detected in Quzhou. Both of these were lower than that of the coldest winter during the instrumental observation period of 1951-2010. This research could not only provide a method to es-timate historical climate extremes, but also provide a background to understand the recent instrumentally climate extremes.

  6. Assessment of indices of temperature extremes simulated by multiple CMIP5 models over China

    Science.gov (United States)

    Dong, Siyan; Xu, Ying; Zhou, Botao; Shi, Ying

    2015-08-01

    Given that climate extremes in China might have serious regional and global consequences, an increasing number of studies are examining temperature extremes in China using the Coupled Model Intercomparison Project Phase 5 (CMIP5) models. This paper investigates recent changes in temperature extremes in China using 25 state-of-the-art global climate models participating in CMIP5. Thirteen indices that represent extreme temperature events were chosen and derived by daily maximum and minimum temperatures, including those representing the intensity (absolute indices and threshold indices), duration (duration indices), and frequency (percentile indices) of extreme temperature. The overall performance of each model is summarized by a "portrait" diagram based on relative root-mean-square error, which is the RMSE relative to the median RMSE of all models, revealing the multi-model ensemble simulation to be better than individual model for most indices. Compared with observations, the models are able to capture the main features of the spatial distribution of extreme temperature during 1986-2005. Overall, the CMIP5 models are able to depict the observed indices well, and the spatial structure of the ensemble result is better for threshold indices than frequency indices. The spread amongst the CMIP5 models in different subregions for intensity indices is small and the median CMIP5 is close to observations; however, for the duration and frequency indices there can be wide disagreement regarding the change between models and observations in some regions. The model ensemble also performs well in reproducing the observational trend of temperature extremes. All absolute indices increase over China during 1961-2005.

  7. Creep strength of iridium at extremely high temperatures; Zeitstandfestigkeit von Iridium bei extrem hohen Temperaturen

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, B. [Fachhochschule Jena (Germany). Fachbereich Werkstofftechnik; Lupton, D. [Heraeus (W.C.) GmbH, Hanau (Germany). Produktbereich Materialtechnik; Braun, F. [Heraeus (W.C.) GmbH, Hanau (Germany). Produktbereich Materialtechnik; Merker, J. [Jena Univ. (Germany). Technisches Inst.; Helmich, R. [Jena Univ. (Germany). Technisches Inst.

    1994-12-31

    On iridium in the initial state and after carrying out creep tests, apart from metallographic and fractographic work, investigations on the distribution of trace impurities were done by means of secondary ion mass spectroscopy and investigations of the crystal structure were carried out with the aid of Kossel technique, a special field of X-ray bending. Although iridium of high purity was used for the investigations, enrichment of hydrogen, carbon, sodium, potassium, calcium, magnesium, silicon, iron, nickel and chromium was proved by means of secondary ion mass spectroscopy at the grain boundaries, where the average contents in iridium were only about 1 {mu}g/g. In the creep test, creep fracture lines were found in the range of 1800 to 2300 C and about 0.5 to 12 hours on iridium samples with a square cross section of 1 mm. It follows from the results that this noble metal has a considerable resistance to heat at these temperatures, which makes its use up to 2300 C possible. (orig./RHM) [Deutsch] Es erfolgten am Iridium im Ausgangszustand und nach Durchfuehrung der Zeitstandversuche neben metallographischen und fraktographischen Arbeiten Untersuchungen zur Verteilung der Spurenverunreinigungen mittels Sekundaerionen-Massenspektroskopie sowie Untersuchungen der Kristallstruktur mit Hilfe der Kossel-Technik, einem Spezialgebiet der Roentgenbeugung. Obwohl fuer die Untersuchungen hochreines Iridium verwendet wurde, konnten mittels Sekundaerionen-Massenspektroskopie in den Korngrenzen Anreicherungen von Wasserstoff, Kohlenstoff, Natrium, Kalium, Calcium, Magnesium, Silizium, Eisen, Nickel und Chrom nachgewiesen werden, wobei die durchschnittlichen Gehalte in Iridium nur um 1 {mu}g/g lagen. Im Zeitstandversuch wurden an Iridiumproben mit 1 mm Vierkantquerschnitt Zeitbruchlinien im Bereich von 1800 bis 2300 C und etwa 0,5 bis 12 Stunden aufgenommen. Aus den Ergebnissen folgt, dass das Edelmetall bei diesen Temperaturen noch eine beachtliche Warmfestigkeit besitzt, die

  8. Lack of Dependence of Indian Summer Monsoon Rainfall Extremes on Temperature: An Observational Evidence

    Science.gov (United States)

    Vittal, H.; Ghosh, Subimal; Karmakar, Subhankar; Pathak, Amey; Murtugudde, Raghu

    2016-08-01

    The intensification of precipitation extremes in a warming world has been reported on a global scale and is traditionally explained with the Clausius-Clapeyron (C-C) relation. The relationship is observed to be valid in mid-latitudes; however, the debate persists in tropical monsoon regions, with the extremes of the Indian Summer Monsoon Rainfall (ISMR) being a prime example. Here, we present a comprehensive study on the dependence of ISMR extremes on both the 2 m surface air temperature over India and on the sea surface temperature over the tropical Indian Ocean. Remarkably, the ISMR extremes exhibit no significant association with temperature at either spatial scale: neither aggregated over the entire India/Tropical Indian Ocean area nor at the grid levels. We find that the theoretical C-C relation overestimates the positive changes in precipitation extremes, which is also reflected in the Coupled Model Intercomparison Project 5 (CMIP5) simulations. We emphasize that the changing patterns of extremes over the Indian subcontinent need a scientific re-evaluation, which is possible due to availability of the unique long-term in-situ data. This can aid bias correction of model projections of extremes whose value for climate adaptation can hardly be overemphasized, especially for the developing tropical countries.

  9. Multi-Model Projection of July-August Climate Extreme Changes over China under CO2 Doubling. Part II: Temperature

    Institute of Scientific and Technical Information of China (English)

    LI Hongmei; FENG Lei; ZHOU Tianjun

    2011-01-01

    This is the second part of the authors' analysis on the output of 24 coupled climate models from the Twentieth-Century Climate in Coupled Models (20C3M) experiment and 1% per year CO2 increase experiment (to doubling) (lpctto2x) of phase 3 of the Coupled Model Inter-comparison Project (CMIP3). The study focuses on the potential changes of July-August temperature extremes over China. The pattern correlation coefficients of the simulated temperature with the observations are 0.6-0.9, which are higher than the results for precipitation. However, most models have cold bias compared to observation, with a larger cold bias over western China (>5℃) than over eastern China (<2℃). The multi-model ensemble (MME)exhibits a significant increase of temperature under the lpctto2x scenario. The amplitude of the MME warming shows a northwest-southeast decreasing gradient. The warming spread among the models (~1℃-2℃) is less than MME warming (~2℃-4℃), indicating a relativelyrobust temperature change under CO2doubling. Further analysis of Geophysical Fluid Dynamics Laboratory coupled climate model version 2.1(GFDL-CM2.1) simulations suggests that the warming pattern may be related to heat transport by summer monsoons. The contrast of cloud effects also has contributions. The different vertical structures of warming over northwestern China and southeastern China may be attributed to the different natures of vertical circulations. The deep, moist convection over southeastern China is an effective mechanism for "transporting"the warming upward, leading to more upper-level warming. In northwestern China, the warming is more surface-orientated, possibly due to the shallow, dry convection.

  10. W(310) cold-field emission characteristics reflecting the vacuum states of an extreme high vacuum electron gun

    Science.gov (United States)

    Cho, Boklae; Shigeru, Kokubo; Oshima, Chuhei

    2013-01-01

    An extremely high vacuum cold-field electron emission (CFE) gun operating at pressures ranging from ˜10-8 Pa to ˜10-10 Pa was constructed. Only the CFE current emitting from W(310) surfaces revealed the existence of a "stable region" with high current angular density just after tip flash heating. In the "stable region," the CFE current was damped very slowly. The presence of non-hydrogen gas eliminated this region from the plot. Improvement of the vacuum prolonged the 90% damping time of the CFE current from ˜10 min to 800 min. The current angular density I' of CFE current was 60 and 250 μA/sr in the "stable region" for total CFE currents of 10 and 50 μA, respectively. These results were about three times larger than I' when measured after the complete damping of the CFE current. The CFE gun generated bright scanning transmission electron microscopy images of a carbon nanotube at 30 kV.

  11. On the influence of cold work on the oxidation behavior of some austenitic stainless steels: High temperature oxidation

    NARCIS (Netherlands)

    Langevoort, J.C.; Fransen, T.; Gellings, P.J.

    1984-01-01

    AISI 304, 314, 321, and Incoloy 800H have been subjected to several pretreatments: polishing, milling, grinding, and cold drawing. In the temperature range 800–1400 K, cold work improves the oxidation resistance of AISI 304 and 321 slightly, but has a relatively small negative effect on the

  12. Sudden cold temperature delays plant carbon transport and shifts allocation from growth to respiratory demand

    Science.gov (United States)

    Barthel, M.; Cieraad, E.; Zakharova, A.; Hunt, J. E.

    2014-03-01

    Since substrates for respiration are supplied mainly by recent photo-assimilates, there is a strong but time-lagged link between short-term above- and belowground carbon (C) cycling. However, regulation of this coupling by environmental variables is poorly understood. Whereas recent studies focussed on the effect of drought and shading on the link between above- and belowground short-term C cycling, the effect of temperature remains unclear. We used a 13CO2 pulse-chase labelling experiment to investigate the effect of a sudden temperature change from 25 to 10 °C on the short-term coupling between assimilatory C uptake and respiratory loss. The study was done in the laboratory using two-month-old perennial rye-grass plants (Lolium perenne L.). After label application, the δ13C signal of respired shoot and root samples was analysed at regular time intervals using laser spectroscopy. In addition, δ13C was analysed in bulk root and shoot samples. Cold temperature (10 °C) reduced the short-term coupling between shoot and roots by delaying belowground transfer of recent assimilates and its subsequent respiratory use, as indicated by the δ13C signal of root respiration (δ13CRR). That is, the time lag from the actual shoot labelling to the first appearance of the label in 13CRR was about 1.5 times longer under cold temperature. Moreover, analysis of bulk shoot and root material revealed that plants at cold temperature invest relatively more carbon into respiration compared to growth or storage. While the whole plant C turnover increased under cold temperature, the turnover time of the labile C pool decreased, probably because less 13C is used for growth and/or storage. That is, (almost) all recent C remained in the labile pool serving respiration under these conditions. Overall, our results highlight the importance of temperature as a driver of C transport and relative C allocation within the plant-soil system.

  13. Determining Ms temperature on a AISI D2 cold work tool steel using magnetic Barkhausen noise

    Energy Technology Data Exchange (ETDEWEB)

    Huallpa, Edgar Apaza, E-mail: gared1@gmail.com [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil); Sánchez, J. Capó, E-mail: jcapo@usp.br [Departamento de Física, Facultad de Ciencias Naturales, Universidad de Oriente, Av. Patricio Lumumba s/n 90500, Santiago de Cuba (Cuba); Padovese, L.R., E-mail: lrpadove@usp.br [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil); Goldenstein, Hélio, E-mail: hgoldens@usp.br [Escola Politécnica da Universidade de São Paulo, Av. Prof. Mello Moraes 2463, 05508-030 SP (Brazil)

    2013-11-15

    Highlights: ► MBN was used to follow the martensite transformation in a tool steel. ► The results were compared with resistivity experiments. ► The Ms was estimated with Andrews equation coupled to ThermoCalc calculations. The experimental results showed good agreement. -- Abstract: The use of Magnetic Barkhausen Noise (MBN) as a experimental method for measuring the martensite start (Ms) temperature was explored, using as model system a cold-work tool steel (AISI D2) austenitized at a very high temperature (1473 K), so as to transform in sub-zero temperatures. The progress of the transformation was also followed with electrical resistance measurements, optical microscopy and scanning electron microscopy. Both MBN and resistivity measurements showed a change near 230 K during cooling, corresponding to the Ms temperature, as compared with 245 K, estimated with Andrews empirical equation applied to the austenite composition calculated using ThermoCalc.

  14. Precipitation and temperatures extremes in East Africa in past and future climate

    OpenAIRE

    Kuya, Elinah Khasandi

    2016-01-01

    Climate change has increased extreme weather events over the planet. The most robust changes in East Africa (EA) are for daily temperature and precipitation, where high-impact extreme values have become more common. The overall magnitude, seasonal distribution of precipitation and its inter-annual variability have been altered. East Africa experiences some of the most severe convective storms in the world. They can come without warning and are becoming more frequent. These changes present sig...

  15. A Decrease in Temperature and Humidity Precedes Human Rhinovirus Infections in a Cold Climate.

    Science.gov (United States)

    Ikäheimo, Tiina M; Jaakkola, Kari; Jokelainen, Jari; Saukkoriipi, Annika; Roivainen, Merja; Juvonen, Raija; Vainio, Olli; Jaakkola, Jouni J K

    2016-09-02

    Both temperature and humidity may independently or jointly contribute to the risk of human rhinovirus (HRV) infections, either through altered survival and spread of viruses in the environment or due to changes in host susceptibility. This study examined the relationship between short-term variations in temperature and humidity and the risk of HRV infections in a subarctic climate. We conducted a case-crossover study among conscripts (n = 892) seeking medical attention due to respiratory symptoms during their military training and identified 147 HRV cases by real-time PCR. An average temperature, a decline in daily ambient temperature and absolute humidity (AH) during the three preceding days of the onset (hazard period) and two reference periods (a week prior and after the onset) were obtained. The average daily temperature preceding HRV infections was -9.9 ± 4.9 °C and the average AH was 2.2 ± 0.9 g/m³. An average (odds ratios (OR) 1.07 (95% confidence interval (CI) 1.00-1.15)) and maximal (OR 1.08 (1.01-1.17)) change in temperature increased the risk of HRV infections by 8% per 1 °C decrease. An average (OR 1.20 (CI 1.03-1.40)) and maximal decrease (OR 1.13 (CI 0.96-1.34)) in AH increased the risk of HRV infection by 13% and 20% per 0.5 g/m³ decrease. A higher average temperature during the three preceding days was positively associated with HRV infections (OR 1.07 (CI 1.00-1.15)). A decrease rather than low temperature and humidity per se during the preceding few days increases the risk of HRV infections in a cold climate. The information is applicable to populations residing in cold climates for appropriate personal protection and prevention of adverse health effects.

  16. Coldest Temperature Extreme Monotonically Increased and Hottest Extreme Oscillated over Northern Hemisphere Land during Last 114 Years

    Science.gov (United States)

    Zhou, Chunlüe; Wang, Kaicun

    2016-05-01

    Most studies on global warming rely on global mean surface temperature, whose change is jointly determined by anthropogenic greenhouse gases (GHGs) and natural variability. This introduces a heated debate on whether there is a recent warming hiatus and what caused the hiatus. Here, we presented a novel method and applied it to a 5° × 5° grid of Northern Hemisphere land for the period 1900 to 2013. Our results show that the coldest 5% of minimum temperature anomalies (the coldest deviation) have increased monotonically by 0.22 °C/decade, which reflects well the elevated anthropogenic GHG effect. The warmest 5% of maximum temperature anomalies (the warmest deviation), however, display a significant oscillation following the Atlantic Multidecadal Oscillation (AMO), with a warming rate of 0.07 °C/decade from 1900 to 2013. The warmest (0.34 °C/decade) and coldest deviations (0.25 °C/decade) increased at much higher rates over the most recent decade than last century mean values, indicating the hiatus should not be interpreted as a general slowing of climate change. The significant oscillation of the warmest deviation provides an extension of previous study reporting no pause in the hottest temperature extremes since 1979, and first uncovers its increase from 1900 to 1939 and decrease from 1940 to 1969.

  17. THE DEPENDENCE OF HEAT CONSUMPTION ON THE DYNAMICS OF EXTERNAL AIR TEMPERATURE DURING COLD SNAP PERIODS

    Directory of Open Access Journals (Sweden)

    Rymarov Andrey Georgievich

    2014-09-01

    Full Text Available The dynamics of outdoor temperature variations during the cold period of the year influences the operation of the systems providing the required microclimate in the premises, which may be subject to automation systems that affects the IQ of a building, it is important to note that in the last decade there has been a growth in the participation of intelligent technologies in the formation of a microclimate of buildings. Studying the microclimate quality in terms of energy consumption of the premises and the building considers climate variability and outdoor air pollution, which is connected with the economic aspects of energy efficiency and productivity, and health of workers, as a short-term temperature fall in the premises has harmful consequences. Low outdoor temperatures dry the air in the premises that requires accounting for climate control equipment and, if necessary, the personal account of its work. Excess heat in the premises, including office equipment, corrects the temperature conditions, which reduces the adverse effect of cold snap.

  18. Importance of freeze-thaw events in low temperature ecotoxicology of cold tolerant enchytraeids.

    Science.gov (United States)

    Silva, Ana L Patrício; Enggrob, Kirsten; Slotsbo, Stine; Amorim, Mónica J B; Holmstrup, Martin

    2014-08-19

    Due to global warming it is predicted that freeze-thaw cycles will increase in Arctic and cold temperate regions. The effects of this variation becomes of particular ecological importance to freeze-tolerant species when it is combined with chemical pollutants. We compared the effect of control temperature (2 °C), daily freeze-thaw cycles (2 to -4 °C) and constant freezing (-2 °C) temperatures on the cold-tolerance of oligochaete worms (Enchytraeus albidus) and tested how survival was influenced by pre-exposure to 4-nonylphenol (4-NP), a common nonionic detergent found in sewage sludge amended soils. Results showed that combined effect of 4-NP and daily freeze-thaw cycles can cause higher mortality to worms as compared with sustained freezing or control temperature. Exposure to 4-NP caused a substantial depletion of glycogen reserves which is catabolized during freezing to produce cryoprotective concentrations of free glucose. Further, exposure to freeze-thaw cycles resulted in higher concentrations of 4-NP in worm tissues as compared to constant freezing or control temperature (2 °C). Thus, worms exposed to combined effect of freeze-thaw cycles and 4-NP suffer higher consequences, with the toxic effect of the chemical potentiating the deleterious effects of freezing and thawing.

  19. Effects of gas temperature on nozzle damping experiments on cold-flow rocket motors

    Science.gov (United States)

    Sun, Bing-bing; Li, Shi-peng; Su, Wan-xing; Li, Jun-wei; Wang, Ning-fei

    2016-09-01

    In order to explore the impact of gas temperature on the nozzle damping characteristics of solid rocket motor, numerical simulations were carried out by an experimental motor in Naval Ordnance Test Station of China Lake in California. Using the pulse decay method, different cases were numerically studied via Fluent along with UDF (User Defined Functions). Firstly, mesh sensitivity analysis and monitor position-independent analysis were carried out for the computer code validation. Then, the numerical method was further validated by comparing the calculated results and experimental data. Finally, the effects of gas temperature on the nozzle damping characteristics were studied in this paper. The results indicated that the gas temperature had cooperative effects on the nozzle damping and there had great differences between cold flow and hot fire test. By discussion and analysis, it was found that the changing of mainstream velocity and the natural acoustic frequency resulted from gas temperature were the key factors that affected the nozzle damping, while the alteration of the mean pressure had little effect. Thus, the high pressure condition could be replaced by low pressure to reduce the difficulty of the test. Finally, the relation of the coefficients "alpha" between the cold flow and hot fire was got.

  20. Observed changes in seasonal heat waves and warm temperature extremes in the Romanian Carpathians

    Science.gov (United States)

    Micu, Dana; Birsan, Marius-Victor; Dumitrescu, Alexandru; Cheval, Sorin

    2015-04-01

    Extreme high temperature have a large impact on environment and human activities, especially in high elevation areas particularly sensitive to the recent climate warming. The climate of the Romanian Carpathians became warmer particularly in winter, spring and summer, exibiting a significant increasing frequency of warm extremes. The paper investigates the seasonal changes in the frequency, duration and intensity of heat waves in relation to the shifts in the daily distribution of maximum temperatures over a 50-year period of meteorological observations (1961-2010). The paper uses the heat wave definition recommended by the Expert Team on Climate Change Detection and Indices (ETCCDI) and exploits the gridded daily dataset of maximum temperature at 0.1° resolution (~10 km) developed in the framework of the CarpatClim project (www.carpatclim.eu). The seasonal changes in heat waves behavior were identified using the Mann-Kendall non-parametric trend test. The results suggest an increase in heat wave frequency and a lengthening of intervals affected by warm temperature extremes all over the study region, which are explained by the shifts in the upper (extreme) tail of the daily maximum temperature distribution in most seasons. The trends are consistent across the region and are well correlated to the positive phases of the East Atlantic Oscillation. Our results are in good agreement with the previous temperature-related studies concerning the Carpathian region. This study was realized within the framework of the project GENCLIM, financed by UEFISCDI, code PN-II 151/2014.

  1. What drives cold-related excess mortality in a south Asian tropical monsoon climate-season vs. temperatures and diurnal temperature changes

    Science.gov (United States)

    Burkart, Katrin; Kinney, Patrick L.

    2016-12-01

    Despite the tropical climate which is characterized by generally high temperatures and persistent mild temperatures during the winter season, Bangladesh, along with many other tropical countries, experiences strong winter and cold-related excess mortality. The objective of this paper was to analyse the nature of these cold effects and understand the role of season vs. temperature and diurnal changes in temperature. For approaching these questions, we applied different Poisson regression models. Temperature as well as diurnal temperature range (DTR) were considered as predictor variables. Different approaches to seasonality adjustment were evaluated and special consideration was given to seasonal differences in atmospheric effects. Our findings show that while seasonality adjustment affected the magnitude of cold effects, cold-related mortality persisted regardless the adjustment approach. Strongest effects of low temperatures were observed at the same day (lag 1) with an increase of 1.7% (95% CI = 0.86-2.54%) per 1 °C decrease in temperature during the winter season. Diurnal temperature affected mortality with increasing levels at higher ranges. Mortality increased with 0.97% (95% CI = 0.17-1.75%) when looking at the entire season, but effects of DTR were not significant during winter when running a seasonal model. Different from effects observed in the mid-latitudes, cold effects in Bangladesh occurred on a very short time scale highlighting the role of temperature versus season. Insufficient adaptation with regard to housing and clothing might lead to such cold-related increases in mortality despite rather moderate temperature values. Although the study did not demonstrate an effect of DTR during the cold season, the strong correlation with (minimum) temperature might cause a multicollinearity problem and effects are difficult to attribute to one driver.

  2. Scaling of precipitation extremes with temperature in the French Mediterranean region: What explains the hook shape?

    Science.gov (United States)

    Drobinski, P.; Alonzo, B.; Bastin, S.; Silva, N. Da; Muller, C.

    2016-04-01

    Expected changes to future extreme precipitation remain a key uncertainty associated with anthropogenic climate change. Extreme precipitation has been proposed to scale with the precipitable water content in the atmosphere. Assuming constant relative humidity, this implies an increase of precipitation extremes at a rate of about 7% °C-1 globally as indicated by the Clausius-Clapeyron relationship. Increases faster and slower than Clausius-Clapeyron have also been reported. In this work, we examine the scaling between precipitation extremes and temperature in the present climate using simulations and measurements from surface weather stations collected in the frame of the HyMeX and MED-CORDEX programs in Southern France. Of particular interest are departures from the Clausius-Clapeyron thermodynamic expectation, their spatial and temporal distribution, and their origin. Looking at the scaling of precipitation extreme with temperature, two regimes emerge which form a hook shape: one at low temperatures (cooler than around 15°C) with rates of increase close to the Clausius-Clapeyron rate and one at high temperatures (warmer than about 15°C) with sub-Clausius-Clapeyron rates and most often negative rates. On average, the region of focus does not seem to exhibit super Clausius-Clapeyron behavior except at some stations, in contrast to earlier studies. Many factors can contribute to departure from Clausius-Clapeyron scaling: time and spatial averaging, choice of scaling temperature (surface versus condensation level), and precipitation efficiency and vertical velocity in updrafts that are not necessarily constant with temperature. But most importantly, the dynamical contribution of orography to precipitation in the fall over this area during the so-called "Cevenoles" events, explains the hook shape of the scaling of precipitation extremes.

  3. Long-term trends and extremes in observed daily precipitation and near surface air temperature in the Philippines for the period 1951-2010

    Science.gov (United States)

    Cinco, Thelma A.; de Guzman, Rosalina G.; Hilario, Flaviana D.; Wilson, David M.

    2014-08-01

    Observed daily precipitation and near surface air temperature data from 34 synoptic weather stations in the Philippines for the period 1951-2010 were subjected to trend analysis which revealed an overall warming tendency compared to the normal mean values for the period 1961-1990. This warming trend can be observed in the annual mean temperatures, daily minimum mean temperatures and to a lesser extent, daily maximum mean temperatures. Precipitation and temperature extremes for the period 1951-2010 were also analysed relative to the mean 1961-1990 baseline values. Some stations (Cotabato, Iloilo, Laoag and Tacloban,) show increases in both frequency and intensity of extreme daily rainfall events which are significant at the 95% level with none of the stations showing decreasing trends. The frequency of daily temperature maximum above the 99th percentile (hot days) and nights at the 1st percentile (cold nights) suggests that both days and nights in particular are becoming warmer. Such indicators of a warming trend and increase in extreme events in the Philippines are discussed in the context of similar national, regional (Asia Pacific) and global studies. The relevance of such empirically based climatology studies, particularly for nations such as the Philippines which are increasingly vulnerable to the multiple impacts of global climate change, is also considered.

  4. Aging meat at room and cold temperatures on meat quality and aging loss of sheep carcass

    Directory of Open Access Journals (Sweden)

    Roswita Sunarlim

    2001-03-01

    Full Text Available The aim of this research is to compare the quality of meat of local carcass sheep between fresh and aging meat stored at room temperature for 12 hours, at 4oC for one day and one week. For that purpose a study of aging carcass involving 12 local sheep (male and female with different ages was carried out by separating carcass into two parts: (1 the right portion was aged on 4oC for one day and one week, room temperature for 12 hours, and (2 the left portion as control without aging. A factorial design 2x2 (2 sexes and aging vs without aging for three kinds of aging on quality of meat. A factorial design 2x3 (2 sexes and 3 kinds of aging on aging loss. Replicate twice was carried out with different ages (old and young sheep. Parameter measured were pH, warter-holding capacity, cooking loss, color, tenderness, carcass weight loss. There was decrease in pH, increase in tenderness value for aged meat that stored at room temperature for 12 hours (1.84 kg, at cold temperature for one day (2.03 kg, but tenderness value was the most (0.92 kg at cold temperature for one week compared to fresh meat (3.41, 4.06, and 3.66 kg. Lightness color (l, red color (a and yellow color (b for aged meat is usually increase compare to fresh meat, except for aged meat stored at room temperature for 12 hours was decrease significant. Water-holding capacity and cooking loss value of aged meat was not significant compared to fresh meat. Aging loss of aged meat stored at 4oC for one week (13.58% was significant compared to aged meat stored at room temperature (2.42% and 4oC for one day (2.90%.

  5. Fault Tolerant Magnetic Bearing Testing and Conical Magnetic Bearing Development for Extreme Temperature Environments

    Science.gov (United States)

    Keith, Theo G., Jr.; Clark, Daniel

    2004-01-01

    During the six month tenure of the grant, activities included continued research of hydrostatic bearings as a viable backup-bearing solution for a magnetically levitated shaft system in extreme temperature environments (1000 F), developmental upgrades of the fault-tolerant magnetic bearing rig at the NASA Glenn Research Center, and assisting in the development of a conical magnetic bearing for extreme temperature environments, particularly turbomachinery. It leveraged work from the ongoing Smart Efficient Components (SEC) and the Turbine-Based Combined Cycle (TBCC) program at NASA Glenn Research Center. The effort was useful in providing technology for more efficient and powerful gas turbine engines.

  6. 2012/13 abnormal cold winter in Japan associated with Large-scale Atmospheric Circulation and Local Sea Surface Temperature over the Sea of Japan

    Science.gov (United States)

    Ando, Y.; Ogi, M.; Tachibana, Y.

    2013-12-01

    On Japan, wintertime cold wave has social, economic, psychological and political impacts because of the lack of atomic power stations in the era of post Fukushima world. The colder winter is the more electricity is needed. Wintertime weather of Japan and its prediction has come under the world spotlight. The winter of 2012/13 in Japan was abnormally cold, and such a cold winter has persisted for 3 years. Wintertime climate of Japan is governed by some dominant modes of the large-scale atmospheric circulations. Yasunaka and Hanawa (2008) demonstrated that the two dominant modes - Arctic Oscillation (AO) and Western Pacific (WP) pattern - account for about 65% of the interannual variation of the wintertime mean surface air temperature of Japan. A negative AO brings about cold winter in Japan. In addition, a negative WP also brings about cold winter in Japan. Looking back to the winter of 2012/13, both the negative AO and negative WP continued from October through December. If the previous studies were correct, it would have been extremely very cold from October through December. In fact, in December, in accordance with previous studies, it was colder than normal. Contrary to the expectation, in October and November, it was, however, warmer than normal. This discrepancy signifies that an additional hidden circumstance that heats Japan overwhelms these large-scale atmospheric circulations that cool Japan. In this study, we therefore seek an additional cause of wintertime climate of Japan particularly focusing 2012 as well as the AO and WP. We found that anomalously warm oceanic temperature surrounding Japan overwhelmed influences of the AO or WP. Unlike the inland climate, the island climate can be strongly influenced by surrounding ocean temperature, suggesting that large-scale atmospheric patterns alone do not determine the climate of islands. (a) Time series of a 5-day running mean AO index (blue) as defined by Ogi et al., (2004), who called it the SVNAM index. For

  7. How cold can you get in space? Quantum Physics at cryogenic temperatures in space

    CERN Document Server

    Hechenblaikner, Gerald; Burkhardt, Johannes; Kiesel, Nikolai; Johann, Ulrich; Aspelmeyer, Markus; Kaltenbaek, Rainer

    2013-01-01

    Although it is often believed that the coldness of space is ideally suited for performing measurements at cryogenic temperatures, this must be regarded with caution for two reasons: Firstly, the sensitive instrument must be completely shielded from the strong solar radiation and therefore, e.g. either be placed inside a satellite or externally on the satellite's shaded side. Secondly, any platform hosting such an experiment in space generally provides an environment close to room temperature for the accommodated equipment. To obtain cryogenic temperatures without active cooling, one must isolate the instrument from radiative and conductive heat exchange with the platform as well as possible. We investigate the limits of this passive cooling method in the context of a recently proposed experiment to observe the decoherence of quantum superpositions of massive objects. The analyses and conclusions are applicable to a host of similar experimental designs requiring a cryogenic environment in space.

  8. Study on biodiesel heat transfer through self-temperature limit injector during vehicle cold start

    Directory of Open Access Journals (Sweden)

    Wang Jun

    2015-01-01

    Full Text Available A type of Self-Temperature Limit-Injector (STL- injector is proposed to reduce the biodiesel consumption and emission in vehicle cold start process. The STL-injector is capable of fast raising fuel temperature, which helps improve the quality of diesel spray and its combustion efficiency. A STL-injector model is established with consideration of electro-mechanic coupling and fluid-structure interaction. A transient simulation is conducted using dynamic grid technology. The results show that STL-injector can effectively raise biodiesel temperature to 350K from 300K in 32 seconds. That is to say, adding STL-injector to existing biodiesel combustion system is an environment-friendly solution due to improving atomization and spray quality quickly.

  9. Influence of Gas Temperature on Microstructure and Properties of Cold Spray 304SS Coating

    Institute of Scientific and Technical Information of China (English)

    Xianming Meng; Junbao Zhang; Jie Zhao; Yongli Liang; Yujun Zhang

    2011-01-01

    In the present study, 304 stainless steel coatings were deposited on interstitial-free steel substrates by cold gas dynamic spray technology. The effect of gas temperature on microstructure, micro-hardness, cohesive strength, and electrochemical property of the coatings were investigated and compared. The results showed that increasing gas temperature had a great contribution to enhancing the bonding strength between the deposited particles and making the microstructure more density. Therefore, the porosity of the coatings decreased from 0%4-0.5% to 2%4-0.3%, and the tensile strength of the coatings increased from 564-4 MPa up to 734-3 MPa. In addition, the corrosion resistance of the coatings was also deeply influenced by process gas temperature. The corrosion kinetics of the coatings were affected by both of the plastic deformation of deposited particles and the porosity in the coatings.

  10. Climate change and the effects of temperature extremes on Australian flying-foxes.

    Science.gov (United States)

    Welbergen, Justin A; Klose, Stefan M; Markus, Nicola; Eby, Peggy

    2008-02-22

    Little is known about the effects of temperature extremes on natural systems. This is of increasing concern now that climate models predict dramatic increases in the intensity, duration and frequency of such extremes. Here we examine the effects of temperature extremes on behaviour and demography of vulnerable wild flying-foxes (Pteropus spp.). On 12 January 2002 in New South Wales, Australia, temperatures exceeding 42 degrees C killed over 3500 individuals in nine mixed-species colonies. In one colony, we recorded a predictable sequence of thermoregulatory behaviours (wing-fanning, shade-seeking, panting and saliva-spreading, respectively) and witnessed how 5-6% of bats died from hyperthermia. Mortality was greater among the tropical black flying-fox, Pteropus alecto (10-13%) than the temperate grey-headed flying-fox, Pteropus poliocephalus (less than 1%), and young and adult females were more affected than adult males (young, 23-49%; females, 10-15%; males, less than 3%). Since 1994, over 30000 flying-foxes (including at least 24500 P. poliocephalus) were killed during 19 similar events. Although P. alecto was relatively less affected, it is currently expanding its range into the more variable temperature envelope of P. poliocephalus, which increases the likelihood of die-offs occurring in this species. Temperature extremes are important additional threats to Australian flying-foxes and the ecosystem services they provide, and we recommend close monitoring of colonies where temperatures exceeding 42.0 degrees C are predicted. The effects of temperature extremes on flying-foxes highlight the complex implications of climate change for behaviour, demography and species survival.

  11. Trends in extreme daily temperatures and humidex index in the United Arab Emirates over 1948-2014.

    Science.gov (United States)

    Yang, H. W.; Ouarda, T.

    2015-12-01

    This study deals with the analysis of the characteristics of extreme temperature events in the Middle East, using NCEP reanalysis gridded data, for the summer (May-October) and winter (November-April) seasons. Trends in the occurrences of three types of heat spells during 1948-2014 are studied by both Linear Regression (LR) and Mann-Kendall (MK) test. Changes in the diurnal temperature range (DTR) are also investigated. To better understand the effects of heat spells on public health, the Humidex, a combination index of ambient temperature and relative humidity, is also used. Using percentile threshold, temperature (Humidex) Type-A and Type-B heat spells are defined respectively by daily maximum and minimum temperature (Humidex). Type-C heat spells are defined as the joint occurrence of Type-A and Type-B heat spells at the same time. In the Middle East, it is found that no coherent trend in temperature Type-A heat spells is observed. However, the occurrences of temperature Type-B and C heat spells have consistently increased since 1948. For Humidex heat spells, coherently increased activities of all three types of heat spells are observed in the area. During the summer, the magnitude of the positive trends in Humidex heat spells are generally stronger than temperature heat spells. More than half of the locations in the area show significantly negative DTR trends in the summer, but the trends vary according to the region in the winter. Annual mean temperature has increased an average by 0.5°C, but it is mainly associated with the daily minimum temperature which has warmed up by 0.84°C.Daily maximum temperature showed no significant trends. The warming is hence stronger in minimum temperatures than in maximum temperatures resulting in a decrease in DTR by 0.16 °C per decade. This study indicates hence that the UAE has not become hotter, but it has become less cold during 1948 to 2014.

  12. Explicit formula of finite difference method to estimate human peripheral tissue temperatures during exposure to severe cold stress.

    Science.gov (United States)

    Khanday, M A; Hussain, Fida

    2015-02-01

    During cold exposure, peripheral tissues undergo vasoconstriction to minimize heat loss to preserve the maintenance of a normal core temperature. However, vasoconstricted tissues exposed to cold temperatures are susceptible to freezing and frostbite-related tissue damage. Therefore, it is imperative to establish a mathematical model for the estimation of tissue necrosis due to cold stress. To this end, an explicit formula of finite difference method has been used to obtain the solution of Pennes' bio-heat equation with appropriate boundary conditions to estimate the temperature profiles of dermal and subdermal layers when exposed to severe cold temperatures. The discrete values of nodal temperature were calculated at the interfaces of skin and subcutaneous tissues with respect to the atmospheric temperatures of 25 °C, 20 °C, 15 °C, 5 °C, -5 °C and -10 °C. The results obtained were used to identify the scenarios under which various degrees of frostbite occur on the surface of skin as well as the dermal and subdermal areas. The explicit formula of finite difference method proposed in this model provides more accurate predictions as compared to other numerical methods. This model of predicting tissue temperatures provides researchers with a more accurate prediction of peripheral tissue temperature and, hence, the susceptibility to frostbite during severe cold exposure.

  13. Mapping the cold dust temperatures and masses of nearby Kingfish galaxies with Herschel

    CERN Document Server

    Galametz, M; Albrecht, M; Aniano, G; Armus, L; Bertoldi, F; Calzetti, D; Crocker, A F; Croxall, K V; Dale, D A; Meyer, J Donovan; Draine, B T; Engelbracht, C W; Hinz, J L; Roussel, H; Skibba, R A; Tabatabaei, F S; Walter, F; Weiss, A; Wilson, C D; Wolfire, M G

    2012-01-01

    Taking advantage of the sensitivity and angular resolution of the Herschel Space Observatory at far-infrared and submm wavelengths, we aim to characterize the physical properties of cold dust within nearby galaxies and study the robustness of the parameters we derive using different modified blackbody models. For a pilot subsample of the KINGFISH program, we perform 2 temperature fits of the Spitzer and Herschel photometric data (24 to 500um), with a warm and a cold component, globally and in each resolution element.At global scales, we observe ranges of values for beta_c(0.8 to 2.5) and Tc(19.1 to 25.1K).We compute maps of our parameters with beta fixed or free to test the robustness of the temperature and dust surface density maps we deduce. When the emissivity is fixed, we observe temperature gradients as a function of radius.When the emissivity is fitted as a free parameter, barred galaxies tend to have uniform fitted emissivities.Gathering resolved elements in a Tc-beta_c diagram underlines an anti-corre...

  14. Cold Ambient Temperature Promotes Nosema spp. Intensity in Honey Bees (Apis mellifera).

    Science.gov (United States)

    Retschnig, Gina; Williams, Geoffrey R; Schneeberger, Annette; Neumann, Peter

    2017-02-09

    Interactions between parasites and environmental factors have been implicated in the loss of managed Western honey bee (=HB, Apis mellifera) colonies. Although laboratory data suggest that cold temperature may limit the spread of Nosema ceranae, an invasive species and now ubiquitous endoparasite of Western HBs, the impact of weather conditions on the distribution of this microsporidian in the field is poorly understood. Here, we conducted a survey for Nosema spp. using 18 Swiss apiaries (four colonies per apiary) over a period of up to 18 months. Samples consisting of 60 workers were collected monthly from each colony to estimate Nosema spp. intensity, i.e., the number of spores in positive samples using microscopy. Ambient apiary temperature was measured daily to estimate the proportion of days enabling HB flight (>10 °C at midday). The results show that Nosema spp. intensities were negatively correlated with the proportion of days enabling HB flight, thereby suggesting a significant and unexpected positive impact of cold ambient temperature on intensities, probably via regulation of defecation opportunities for infected hosts.

  15. Cold Ambient Temperature Promotes Nosema spp. Intensity in Honey Bees (Apis mellifera

    Directory of Open Access Journals (Sweden)

    Gina Retschnig

    2017-02-01

    Full Text Available Interactions between parasites and environmental factors have been implicated in the loss of managed Western honey bee (=HB, Apis mellifera colonies. Although laboratory data suggest that cold temperature may limit the spread of Nosema ceranae, an invasive species and now ubiquitous endoparasite of Western HBs, the impact of weather conditions on the distribution of this microsporidian in the field is poorly understood. Here, we conducted a survey for Nosema spp. using 18 Swiss apiaries (four colonies per apiary over a period of up to 18 months. Samples consisting of 60 workers were collected monthly from each colony to estimate Nosema spp. intensity, i.e., the number of spores in positive samples using microscopy. Ambient apiary temperature was measured daily to estimate the proportion of days enabling HB flight (>10 °C at midday. The results show that Nosema spp. intensities were negatively correlated with the proportion of days enabling HB flight, thereby suggesting a significant and unexpected positive impact of cold ambient temperature on intensities, probably via regulation of defecation opportunities for infected hosts.

  16. Nonlinear analysis for the coupled problem of temperature and seepage fields in cold regions tunnels

    Institute of Scientific and Technical Information of China (English)

    赖远明; 吴紫汪; 朱元林; 何春雄; 朱林楠

    1999-01-01

    The governing differential equations of the coupled problem of temperature and seepage fields with phase change are first derived from the theory of heat transfer and the theory of seepage. The finite element formulae of this problem are obtained from Galerkin’ s method. And considering the seepage influence, an illustrative example of thetemperature field in a cold-region tunnel is provided.The example shows that the influence of seepage on the frozen depth of the tunnel is very great, and thus the effect of the seepage factor should be taken into account in the engineering design.

  17. Does viviparity evolve in cold climate reptiles because pregnant females maintain stable (not high) body temperatures?

    Science.gov (United States)

    Shine, Richard

    2004-08-01

    Viviparity (live bearing) has evolved from egg laying (oviparity) in many lineages of lizards and snakes, apparently in response to occupancy of cold climates. Explanations for this pattern have focused on the idea that behaviorally thermoregulating (sun-basking) pregnant female reptiles can maintain higher incubation temperatures for their embryos than would be available in nests under the soil surface. This is certainly true at very high elevations, where only viviparous species occur. However, comparisons of nest and lizard temperatures at sites close to the upper elevational limit for oviparous reptiles (presumably, the selective environment where the transition from oviparity to viviparity actually occurs) suggest that reproductive mode has less effect on mean incubation temperatures than on the diel distribution of those temperatures. Nests of the oviparous scincid lizard Bassiana duperreyi showed smooth diel cycles of heating and cooling. In contrast, body temperatures of the viviparous scincid Eulamprus heatwolei rose abruptly in the morning, were high and stable during daylight hours, and fell abruptly at night. Laboratory incubation experiments mimicking these patterns showed that developmental rates of eggs and phenotypic traits of hatchling B. duperreyi were sensitive to this type of thermal variance as well as to mean temperature. Hence, diel distributions as well as mean incubation temperatures may have played an important role in the selective forces for viviparity. More generally, variances as well as mean values of abiotic factors may constitute significant selective forces on life-history evolution.

  18. The effects of anesthetic technique and ambient temperature on thermoregulation in lower extremity surgery.

    Science.gov (United States)

    Ozer, Ayse B; Tosun, Fadime; Demirel, Ismail; Unlu, Serap; Bayar, Mustafa K; Erhan, Omer L

    2013-08-01

    The purpose of our study was to determine the effects of anesthetic technique and ambient temperature on thermoregulation for patients undergoing lower extremity surgery. Our study included 90 male patients aged 18-60 years in American Society of Anesthesiologists Physical Status groups I or II who were scheduled for lower extremity surgery. Patients were randomly divided into three groups according to anesthetic technique: general anesthesia (GA), epidural anesthesia (EA), and femoral-sciatic block (FS). These groups were divided into subgroups according to room temperature: the temperature for group I was 20-22 °C and that for group II was 23-25 °C. Therefore, we labeled the groups as follows: GA I, GA II, EA I, EA II, FS I, and FS II. Probes for measuring tympanic membrane and peripheral temperature were placed in and on the patients, and mean skin temperature (MST) and mean body temperature (MBT) were assessed. Postoperative shivering scores were recorded. During anesthesia, tympanic temperature and MBT decreased whereas MST increased for all patients. There was no significant difference between tympanic temperatures in either the room temperature or anesthetic method groups. MST was lower in group GA I than in group GA II after 5, 10, 15, 20, 60 and 90 min whereas MBT was significantly lower at the basal level (p thermoregulation among anesthetic techniques. Room temperature affected thermoregulation in Group GA.

  19. Estrous cycle fluctuations in sex and ingestive behavior are accentuated by exercise or cold ambient temperatures.

    Science.gov (United States)

    Abdulhay, Amir; Benton, Noah A; Klingerman, Candice M; Krishnamoorthy, Kaila; Brozek, Jeremy M; Schneider, Jill E

    2014-06-01

    This article is part of a Special Issue "Energy Balance". In female Syrian hamsters (Mesocricetus auratus), low circulating levels of ovarian steroids are associated with increased food hoarding and decreased sexual motivation, but these effects are exaggerated in food-restricted females. To determine whether cold ambient temperature has the same effects as food restriction, groups of hamsters were fed ad libitum while they were housed at either 5 °C or 22 °C, and then tested for behavior for 90 min on each day of the estrous cycle. In females housed at 22 °C, high levels of sexual motivation and low levels of food hoarding were seen every day of the estrous cycle. In females housed at 5 °C, high levels of sexual motivation were restricted to the periovulatory day. On the three nonestrous days, these females showed high levels of food hoarding, but not food intake. A separate cohort of females were provided with access to running wheels and housed at 22 °C. They showed high levels of sexual motivation restricted to the periovulatory day, similar to the pattern of sexual motivation seen in cold-housed females. Unlike cold-housed females, those with running wheels showed low levels of food hoarding and high levels of food intake. Food restriction, cold housing, and access to wheels had no significant effect on plasma estradiol or progesterone concentrations, but significantly decreased plasma leptin concentrations. All three energetic challenges unmask estrous cycle fluctuations in sexual motivation that are obscured in laboratory conditions, i.e., isolation in a small cage with an overabundance of food.

  20. Two-dimensional Electrophoresis Analysis of Proteins in Response to Cold Stress in Extremely Cold-resistant Winter Wheat Dongnongdongmai 1 Tillering Nodes

    Institute of Scientific and Technical Information of China (English)

    Cang Jing; Yu Jing; Liu Li-jie; Yang Yang; Cui Hong; Hao Zai-bin; Li Zhuo-fu

    2012-01-01

    The overwintering survival ratio of the cultivar Dongnongdongmai 1 with strong cold-resistance in paramos of Heilongjiang Province in China are over 85%. The tillering nodes are the most important organs for overwintering survival of winter wheat, because there are more substances associated with cold resistance in tillering nodes than those in leaves and roots. Proteins in the tillering nodes of the cold-resistant cultivar Dongnongdongmai 1 grown under field conditions with or without any lowtemperature stress were analyzed by 2-dimensional electrophoresis and identified by mass spectrometry. In the range of pH 4-7, the expression of 37 proteins showed obvious difference (±more than two fold) in the proteomic maps of cold-stressed and non-stressed tillering nodes, including a new protein spot. All proteins exhibiting the difference in expression were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, followed by a database search for protein identification and function prediction. Five groups of proteins were confirmed, namely stress-related proteins (22%), metabolism-associated proteins (35%), and signaling molecules (24%), cell wall-binding proteins (5%), unclear proteins (14%). This indicated that tillering node cells supported the energy requirements of plant growth and stress resistance by signal transduction adapting to metabolism and structure.

  1. Temperature response functions introduce high uncertainty in modelled carbon stocks in cold temperature regimes

    Directory of Open Access Journals (Sweden)

    H. Portner

    2009-08-01

    Full Text Available Models of carbon cycling in terrestrial ecosystems contain formulations for the dependence of respiration on temperature, but the sensitivity of predicted carbon pools and fluxes to these formulations and their parameterization is not understood. Thus, we made an uncertainty analysis of soil organic matter decomposition with respect to its temperature dependency using the ecosystem model LPJ-GUESS.

    We used five temperature response functions (Exponential, Arrhenius, Lloyd-Taylor, Gaussian, Van't Hoff. We determined the parameter uncertainty ranges of the functions by nonlinear regression analysis based on eight experimental datasets from northern hemisphere ecosystems. We sampled over the uncertainty bounds of the parameters and run simulations for each pair of temperature response function and calibration site. The uncertainty in both long-term and short-term soil carbon dynamics was analyzed over an elevation gradient in southern Switzerland.

    The function of Lloyd-Taylor turned out to be adequate for modelling the temperature dependency of soil organic matter decomposition, whereas the other functions either resulted in poor fits (Exponential, Arrhenius or were not applicable for all datasets (Gaussian, Van't Hoff. There were two main sources of uncertainty for model simulations: (1 the uncertainty in the parameter estimates of the response functions, which increased with increasing temperature and (2 the uncertainty in the simulated size of carbon pools, which increased with elevation, as slower turn-over times lead to higher carbon stocks and higher associated uncertainties. The higher uncertainty in carbon pools with slow turn-over rates has important implications for the uncertainty in the projection of the change of soil carbon stocks driven by climate change, which turned out to be more uncertain for higher elevations and hence higher latitudes, which are of key importance for the global terrestrial carbon

  2. Characteristics of the spatiotemporal distribution of daily extreme temperature events in China: Minimum temperature records in different climate states against the background of the most probable temperature

    Institute of Scientific and Technical Information of China (English)

    Qian Zhong-Hua; Hu Jing-Guo; Feng Guo-Lin; Cao Yong-Zhong

    2012-01-01

    Based on the skewed function,the most probable temperature is defined and the spatiotemporal distributions of the frequencies and strengths of extreme temperature events in different climate states over China are investigated,where the climate states are referred to as State Ⅰ,State Ⅱ and State Ⅲ,i.e.,the daily minimum temperature records of 1961-1990,1971-2000,and 1981-2009.The results show that in space the frequency of high temperature events in summer decreases clearly in the lower and middle reaches of the Yellow River in State Ⅰ and that low temperature events decrease in northern China in State Ⅱ.In the present state,the frequency of high temperature events increases significantly in most areas over China except the north east,while the frequency of low temperature events decreases mainly in north China and the regions between the Yangtze River and the Yellow River.The distributions of frequencies and strengths of extreme temperature events are consistent in space.The analysis of time evolution of extreme events shows that the occurrence of high temperature events become higher with the change in state,while that of low temperature events decreases.High temperature events are becoming stronger as well and deserve to be paid special attention.

  3. Extreme Sensitivity of Room-Temperature Photoelectric Effect for Terahertz Detection.

    Science.gov (United States)

    Huang, Zhiming; Zhou, Wei; Tong, Jinchao; Huang, Jingguo; Ouyang, Cheng; Qu, Yue; Wu, Jing; Gao, Yanqing; Chu, Junhao

    2016-01-01

    Extreme sensitivity of room-temperature photoelectric effect for terahertz (THz) detection is demonstrated by generating extra carriers in an electromagnetic induced well located at the semiconductor, using a wrapped metal-semiconductor-metal configuration. The excellent performance achieved with THz detectors shows great potential to open avenues for THz detection.

  4. How to apply the dependence structure analysis to extreme temperature and precipitation for disaster risk assessment

    Science.gov (United States)

    Feng, Jieling; Li, Ning; Zhang, Zhengtao; Chen, Xi

    2017-06-01

    IPCC reports that a changing climate can affect the frequency and the intensity of extreme events. However, the extremes appear in the tail of the probability distribution. In order to know the relationship between extreme events in the tail of temperature and precipitation, an important but previously unobserved dependence structure is analyzed in this paper. Here, we examine the dependence structure by building a bivariate joint of Gumbel copula model for temperature and precipitation using monthly average temperature (T) and monthly precipitation (P) data from Beijing station in China covering a period of 1951-2015 and find the dependence structure can be divided into two sections, they are the middle part and the upper tail. We show that T and P have a strong positive correlation in the high tail section (T > 25.85 °C and P > 171.1 mm) (=0.66, p < 0.01) while they do not demonstrate the same relation in the other section, which suggests that the identification of a strong influence of T on extreme P needs help from the dependence structure analysis. We also find that in the high tail section, every 1 °C increase in T is associated with 73.45 mm increase in P. Our results suggested that extreme precipitation fluctuations by changes in temperature will allow the data dependence structure to be included in extreme affect for the disaster risk assessment under future climate change scenarios. Copula bivariate jointed probability distribution is useful to the dependence structure analysis.

  5. Performance of the Micropower Voltage Reference ADR3430 Under Extreme Temperatures

    Science.gov (United States)

    Patterson, Richard L.; Hammoud, Ahmad

    2011-01-01

    Electronic systems designed for use in space exploration systems are expected to be exposed to harsh temperatures. For example, operation at cryogenic temperatures is anticipated in space missions such as polar craters of the moon (-223 C), James Webb Space Telescope (-236 C), Mars (-140 C), Europa (-223 C), Titan (-178 C), and other deep space probes away from the sun. Similarly, rovers and landers on the lunar surface, and deep space probes intended for the exploration of Venus are expected to encounter high temperature extremes. Electronics capable of operation under extreme temperatures would not only meet the requirements of future spacebased systems, but would also contribute to enhancing efficiency and improving reliability of these systems through the elimination of the thermal control elements that present electronics need for proper operation under the harsh environment of space. In this work, the performance of a micropower, high accuracy voltage reference was evaluated over a wide temperature range. The Analog Devices ADR3430 chip uses a patented voltage reference architecture to achieve high accuracy, low temperature coefficient, and low noise in a CMOS process [1]. The device combines two voltages of opposite temperature coefficients to create an output voltage that is almost independent of ambient temperature. It is rated for the industrial temperature range of -40 C to +125 C, and is ideal for use in low power precision data acquisition systems and in battery-powered devices. Table 1 shows some of the manufacturer s device specifications.

  6. Effects of ambient room temperature on cold air cooling during laser hair removal.

    Science.gov (United States)

    Ram, Ramin; Rosenbach, Alan

    2007-09-01

    Forced air cooling is a well-established technique that protects the epidermis during laser heating of deeper structures, thereby allowing for increased laser fluences. The goal of this prospective study was to identify whether an elevation in ambient room temperature influences the efficacy of forced air cooling. Skin surface temperatures were measured on 24 sites (12 subjects) during cold air exposure in examination rooms with ambient temperatures of 72 degrees F (22.2 degrees C) and 82 degrees F (27.8 degrees C), respectively. Before cooling, mean skin surface temperature was 9 degrees F (5 degrees C) higher in the warmer room (P cooling (within 1 s), the skin surface temperature remained considerably higher (10.75 degrees F, or 5.8 degrees C, P cooling in a room with an ambient temperature of 82 degrees F (27.8 degrees C) is not as effective as in a room that is at 72 degrees F (22.2 degrees C).

  7. Variations in morphological and life-history traits under extreme temperatures in Drosophila ananassae

    Indian Academy of Sciences (India)

    Seema Sisodia; B N Singh

    2009-06-01

    Using half-sib analysis, we analysed the consequences of extreme rearing temperatures on genetic and phenotypic variations in the morphological and life-history traits of Drosophila ananassae. Paternal half-sib covariance contains a relatively small proportion of the epistatic variance and lacks the dominance variance and variance due to maternal effect, which provides more reliable estimates of additive genetic variance. Experiments were performed on a mass culture population of D. ananassae collected from Kanniyakumari (India). Two extremely stressful temperatures (18°C and 32°C) and one standard temperature (25°C) were used to examine the effect of stressful and non-stressful environments on the morphological and life-history traits in males and females. Mean values of various morphological traits differed significantly among different temperature regimens in both males and females. Rearing at 18°C and 32°C resulted in decreased thorax length, wing-to-thorax (w/t) ratio, sternopleural bristle number, ovariole number, sex comb-tooth number and testis length. Phenotypic variances increased under stressful temperatures in comparison with non-stressful temperatures. Heritability and evolvability based on among-sires (males), among-dams (females), and the sum of the two components (sire + dam) showed higher values at both the stressful temperatures than at the non-stressful temperature. These differences reflect changes in additive genetic variance. Viability was greater at the high than the low extreme temperature. As viability is an indicator of stress, we can assume that stress was greater at 18°C than at 32°C in D. ananassae. The genetic variations for all the quantitative and life-history traits were higher at low temperature. Variation in sexual traits was more pronounced as compared with other morphometric traits, which shows that sexual traits are more prone to thermal stress. Our results agree with the hypothesis that genetic variation is increased in

  8. Trainability of cold induced vasodilatation in fingers and toes

    NARCIS (Netherlands)

    Daanen, H.A.M.; Koedam, J.; Cheung, S.S.

    2012-01-01

    Subjects that repeatedly have to expose the extremities to cold may benefit from a high peripheral temperature to maintain dexterity and tissue integrity. Therefore, we investigated if repeated immersions of a hand and a foot in cold water resulted in increased skin temperatures. Nine male and seven

  9. Sauna, shower, and ice water immersion. Physiological responses to brief exposures to heat, cool, and cold. Part III. Body temperatures.

    Science.gov (United States)

    Kauppinen, K

    1989-04-01

    Nine active winter swimmer men were subjected to four exposures each imitating a form of hot or cold exposures or their combination practiced among the Finns: (A) sauna and head-out ice water immersion; (B) sauna and 15 degrees C shower; (C) sauna and room temperature; (D) head-out ice water immersion and room temperature. All exposures were repeated and ended with recovery at room temperature. Body core and surface temperatures were recorded. One surface probe was placed between the scapulae to detect any signs of thermogenic activity by brown adipose tissue upon cold exposures. In the sauna control of core temperature was lost at esophageal temperature Tes 38 degrees C where the mean skin temperature exceeded the Tes. The brief ice water immersions did not disturb the thermal balance of the body core. The interscapular surface temperature recording provided circumstantial evidence of functioning thermogenic tissue in the area.

  10. Trends in atmospheric patterns conducive to seasonal precipitation and temperature extremes in California.

    Science.gov (United States)

    Swain, Daniel L; Horton, Daniel E; Singh, Deepti; Diffenbaugh, Noah S

    2016-04-01

    Recent evidence suggests that changes in atmospheric circulation have altered the probability of extreme climate events in the Northern Hemisphere. We investigate northeastern Pacific atmospheric circulation patterns that have historically (1949-2015) been associated with cool-season (October-May) precipitation and temperature extremes in California. We identify changes in occurrence of atmospheric circulation patterns by measuring the similarity of the cool-season atmospheric configuration that occurred in each year of the 1949-2015 period with the configuration that occurred during each of the five driest, wettest, warmest, and coolest years. Our analysis detects statistically significant changes in the occurrence of atmospheric patterns associated with seasonal precipitation and temperature extremes. We also find a robust increase in the magnitude and subseasonal persistence of the cool-season West Coast ridge, resulting in an amplification of the background state. Changes in both seasonal mean and extreme event configurations appear to be caused by a combination of spatially nonuniform thermal expansion of the atmosphere and reinforcing trends in the pattern of sea level pressure. In particular, both thermal expansion and sea level pressure trends contribute to a notable increase in anomalous northeastern Pacific ridging patterns similar to that observed during the 2012-2015 California drought. Collectively, our empirical findings suggest that the frequency of atmospheric conditions like those during California's most severely dry and hot years has increased in recent decades, but not necessarily at the expense of patterns associated with extremely wet years.

  11. The influence of sour taste and cold temperature in pharyngeal transit duration in patients with stroke

    Directory of Open Access Journals (Sweden)

    Paula Cristina Cola

    2010-03-01

    Full Text Available CONTEXT: The effect of sour taste and food temperature variations in dysphagic patients has not been entirely clarified. OBJECTIVE: To determine the effect of sour and cold food in the pharyngeal transit times of patients with stroke. METHODS: Patients participating in this study were 30 right-handed adults, 16 of which were male and 14 were female, aged 41 to 88 (average age 62.3 years with ictus varying from 1 to 30 days (median of 6 days. To analyze the pharyngeal transit time a videofluoroscopy swallow test was performed. Each patient was observed during swallow of a 5 mL paste bolus given by spoon, totaling four different stimuli (natural, cold, sour and cold sour, one at a time, room temperature (22ºC and cold (8ºC were used. Later, the tests were analyzed using specific software to measure bolus transit time during the pharyngeal phase. RESULTS: The results showed that the pharyngeal transit time was significantly shorter during swallow of cold sour bolus when compared with other stimuli. Conclusion - Sour taste stimuli associated to cold temperature cause significant change in swallowing patterns, by shortening the pharyngeal transit time, which may lead to positive effects in patients with oropharyngeal dysphagia.CONTEXTO: O efeito do sabor azedo e as variações da temperatura dos alimentos em indivíduos disfágicos, ainda não foi totalmente esclarecidos. OBJETIVO: Verificar o efeito do sabor azedo e da temperatura fria no tempo de trânsito faríngeo da deglutição em indivíduos após acidente vascular encefálico hemisférico isquêmico. MÉTODOS: Participaram deste estudo 30 indivíduos adultos, sendo 16 do gênero masculino e 14 do feminino, destros, com faixa etária variando de 41 a 88 anos (média de 62,3 anos e ictus que variou de 1 a 30 dias (mediana de 6 dias. Para analisar o tempo de trânsito faríngeo da deglutição foi realizado o exame de videofluoroscopia da deglutição. Cada indivíduo foi observado durante a

  12. Extreme temperature robust optical sensor designs and fault-tolerant signal processing

    Energy Technology Data Exchange (ETDEWEB)

    Riza, Nabeel Agha (Oviedo, FL); Perez, Frank (Tujunga, CA)

    2012-01-17

    Silicon Carbide (SiC) probe designs for extreme temperature and pressure sensing uses a single crystal SiC optical chip encased in a sintered SiC material probe. The SiC chip may be protected for high temperature only use or exposed for both temperature and pressure sensing. Hybrid signal processing techniques allow fault-tolerant extreme temperature sensing. Wavelength peak-to-peak (or null-to-null) collective spectrum spread measurement to detect wavelength peak/null shift measurement forms a coarse-fine temperature measurement using broadband spectrum monitoring. The SiC probe frontend acts as a stable emissivity Black-body radiator and monitoring the shift in radiation spectrum enables a pyrometer. This application combines all-SiC pyrometry with thick SiC etalon laser interferometry within a free-spectral range to form a coarse-fine temperature measurement sensor. RF notch filtering techniques improve the sensitivity of the temperature measurement where fine spectral shift or spectrum measurements are needed to deduce temperature.

  13. Exposure of embryos to cyclically cold incubation temperatures durably affects energy metabolism and antioxidant pathways in broiler chickens.

    Science.gov (United States)

    Loyau, T; Collin, A; Yenisey, C; Crochet, S; Siegel, P B; Akşit, M; Yalçin, S

    2014-08-01

    Cyclically cold incubation temperatures have been suggested as a means to improve resistance of broiler chickens to ascites; however, the underlying mechanisms are not known. Nine hundred eggs obtained from 48 wk Ross broiler breeders were randomly assigned to 2 incubation treatments: control I eggs were incubated at 37.6°C throughout, whereas for cold I eggs the incubation temperature was reduced by 1°C for 6 h daily from 10 to 18 d of incubation. Thereafter, chickens were reared at standard temperatures or under cold exposure that was associated or not with a postnatal cold acclimation at d 5 posthatch. At hatch, hepatic catalase activity and malondialdehyde content were measured. Serum thyroid hormone and triglyceride concentrations, and muscle expression of several genes involved in the regulation of energy metabolism and oxidative stress were also measured at hatch and 5 and 25 d posthatch. Cold incubation induced modifications in antioxidant pathways with higher catalase activity, but lower expression of avian uncoupling protein 3 at hatch. However, long-term enhancement in the expression of avian uncoupling protein 3 was observed, probably caused by an increase in the expression of the transcription factor peroxisome proliferator activated receptor-γ coactivator-1α. These effects were not systematically associated with an increase in serum triiodothyronine concentrations that were observed only in chickens exposed to both cold incubation and later acclimation at 5 d with cold rearing. Our results suggest that these conditions of cyclically cold incubation resulted in the long-term in changes in antioxidant pathways and energy metabolism, which could enhance the health of chickens reared under cold conditions.

  14. Rising Mediterranean Sea Surface Temperatures Amplify Extreme Summer Precipitation in Central Europe

    Science.gov (United States)

    Volosciuk, Claudia; Maraun, Douglas; Semenov, Vladimir A.; Tilinina, Natalia; Gulev, Sergey K.; Latif, Mojib

    2016-08-01

    The beginning of the 21st century was marked by a number of severe summer floods in Central Europe associated with extreme precipitation (e.g., Elbe 2002, Oder 2010 and Danube 2013). Extratropical storms, known as Vb-cyclones, cause summer extreme precipitation events over Central Europe and can thus lead to such floodings. Vb-cyclones develop over the Mediterranean Sea, which itself strongly warmed during recent decades. Here we investigate the influence of increased Mediterranean Sea surface temperature (SST) on extreme precipitation events in Central Europe. To this end, we carry out atmosphere model simulations forced by average Mediterranean SSTs during 1970-1999 and 2000-2012. Extreme precipitation events occurring on average every 20 summers in the warmer-SST-simulation (2000-2012) amplify along the Vb-cyclone track compared to those in the colder-SST-simulation (1970-1999), on average by 17% in Central Europe. The largest increase is located southeast of maximum precipitation for both simulated heavy events and historical Vb-events. The responsible physical mechanism is increased evaporation from and enhanced atmospheric moisture content over the Mediterranean Sea. The excess in precipitable water is transported from the Mediterranean Sea to Central Europe causing stronger precipitation extremes over that region. Our findings suggest that Mediterranean Sea surface warming amplifies Central European precipitation extremes.

  15. Expected changes in future temperature extremes and their elevation dependency over the Yellow River source region

    Directory of Open Access Journals (Sweden)

    Y. Hu

    2013-07-01

    Full Text Available Using the Statistical DownScaling Model (SDSM and the outputs from two global climate models, we investigate possible changes in mean and extreme temperature indices and their elevation dependency over the Yellow River source region for the two future periods 2046–2065 and 2081–2100 under the IPCC SRES A2, A1B and B1 emission scenarios. Changes in interannual variability of mean and extreme temperature indices are also analyzed. The validation results show that SDSM performs better in reproducing the maximum temperature-related indices than the minimum temperature-related indices. The projections show that by the middle and end of the 21st century all parts of the study region may experience increases in both mean and extreme temperature in all seasons, along with an increase in the frequency of hot days and warm nights and with a decrease in frost days. By the end of the 21st century, interannual variability increases in all seasons for the frequency of hot days and warm nights and in spring for frost days while it decreases for frost days in summer. Autumn demonstrates pronounced elevation-dependent changes in which around six out of eight indices show significant increasing changes with elevation.

  16. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L.; McCulloch, Malcolm T.

    2015-12-01

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  17. Limits to the thermal tolerance of corals adapted to a highly fluctuating, naturally extreme temperature environment.

    Science.gov (United States)

    Schoepf, Verena; Stat, Michael; Falter, James L; McCulloch, Malcolm T

    2015-12-02

    Naturally extreme temperature environments can provide important insights into the processes underlying coral thermal tolerance. We determined the bleaching resistance of Acropora aspera and Dipsastraea sp. from both intertidal and subtidal environments of the naturally extreme Kimberley region in northwest Australia. Here tides of up to 10 m can cause aerial exposure of corals and temperatures as high as 37 °C that fluctuate daily by up to 7 °C. Control corals were maintained at ambient nearshore temperatures which varied diurnally by 4-5 °C, while treatment corals were exposed to similar diurnal variations and heat stress corresponding to ~20 degree heating days. All corals hosted Symbiodinium clade C independent of treatment or origin. Detailed physiological measurements showed that these corals were nevertheless highly sensitive to daily average temperatures exceeding their maximum monthly mean of ~31 °C by 1 °C for only a few days. Generally, Acropora was much more susceptible to bleaching than Dipsastraea and experienced up to 75% mortality, whereas all Dipsastraea survived. Furthermore, subtidal corals, which originated from a more thermally stable environment compared to intertidal corals, were more susceptible to bleaching. This demonstrates that while highly fluctuating temperatures enhance coral resilience to thermal stress, they do not provide immunity to extreme heat stress events.

  18. A Decrease in Temperature and Humidity Precedes Human Rhinovirus Infections in a Cold Climate

    Directory of Open Access Journals (Sweden)

    Tiina M. Ikäheimo

    2016-09-01

    Full Text Available Both temperature and humidity may independently or jointly contribute to the risk of human rhinovirus (HRV infections, either through altered survival and spread of viruses in the environment or due to changes in host susceptibility. This study examined the relationship between short-term variations in temperature and humidity and the risk of HRV infections in a subarctic climate. We conducted a case-crossover study among conscripts (n = 892 seeking medical attention due to respiratory symptoms during their military training and identified 147 HRV cases by real-time PCR. An average temperature, a decline in daily ambient temperature and absolute humidity (AH during the three preceding days of the onset (hazard period and two reference periods (a week prior and after the onset were obtained. The average daily temperature preceding HRV infections was −9.9 ± 4.9 °C and the average AH was 2.2 ± 0.9 g/m3. An average (odds ratios (OR 1.07 (95% confidence interval (CI 1.00–1.15 and maximal (OR 1.08 (1.01–1.17 change in temperature increased the risk of HRV infections by 8% per 1 °C decrease. An average (OR 1.20 (CI 1.03–1.40 and maximal decrease (OR 1.13 (CI 0.96–1.34 in AH increased the risk of HRV infection by 13% and 20% per 0.5 g/m3 decrease. A higher average temperature during the three preceding days was positively associated with HRV infections (OR 1.07 (CI 1.00–1.15. A decrease rather than low temperature and humidity per se during the preceding few days increases the risk of HRV infections in a cold climate. The information is applicable to populations residing in cold climates for appropriate personal protection and prevention of adverse health effects.

  19. Significant influences of global mean temperature and ENSO on extreme rainfall over Southeast Asia

    Science.gov (United States)

    Villafuerte, Marcelino, II; Matsumoto, Jun

    2014-05-01

    Along with the increasing concerns on the consequences of global warming, and the accumulating records of disaster related to heavy rainfall events in Southeast Asia, this study investigates whether a direct link can be detected between the rising global mean temperature, as well as the El Niño-Southern Oscillation (ENSO), and extreme rainfall over the region. The maximum likelihood modeling that allows incorporating covariates on the location parameter of the generalized extreme value (GEV) distribution is employed. The GEV model is fitted to annual and seasonal rainfall extremes, which were taken from a high-resolution gauge-based gridded daily precipitation data covering a span of 57 years (1951-2007). Nonstationarities in extreme rainfall are detected over the central parts of Indochina Peninsula, eastern coasts of central Vietnam, northwest of the Sumatra Island, inland portions of Borneo Island, and on the northeastern and southwestern coasts of the Philippines. These nonstationarities in extreme rainfall are directly linked to near-surface global mean temperature and ENSO. In particular, the study reveals that a kelvin increase in global mean temperature anomaly can lead to an increase of 30% to even greater than 45% in annual maximum 1-day rainfall, which were observed pronouncedly over central Vietnam, southern coast of Myanmar, northwestern sections of Thailand, northwestern tip of Sumatra, central portions of Malaysia, and the Visayas island in central Philippines. Furthermore, a pronounced ENSO influence manifested on the seasonal maximum 1-day rainfall; a northward progression of 10%-15% drier condition over Southeast Asia as the El Niño develops from summer to winter is revealed. It is important therefore, to consider the results obtained here for water resources management as well as for adaptation planning to minimize the potential adverse impact of global warming, particularly on extreme rainfall and its associated flood risk over the region

  20. Can tree-ring density data reflect summer temperature extremes and associated circulation patterns over Fennoscandia?

    Science.gov (United States)

    Zhang, Peng; Ionita, Monica; Lohmann, Gerrit; Chen, Deliang; Linderholm, Hans W.

    2016-12-01

    Tree-ring maximum latewood density (MXD) records from Fennoscandia have been widely used to infer regional- and hemispheric-scale mean temperature variability. Here, we explore if MXD records can also be used to infer past variability of summer temperature extremes across Fennoscandia. The first principal component (PC1) based on 34 MXD chronologies in Fennoscandia explains 50% of the total variance in the observed warm-day extremes over the period 1901-1978. Variations in both observed summer warm-day extremes and PC1 are influenced by the frequency of anomalous anticyclonic pattern over the region, summer sea surface temperatures over the Baltic, North and Norwegian Seas, and the strength of the westerly zonal wind at 200 hPa across Fennoscandia. Both time series are associated with nearly identical atmospheric circulation and SST patterns according to composite map analysis. In a longer context, the first PC based on 3 millennium-long MXD chronologies in central and northern Fennoscandia explains 83% of the total variance of PC1 from the 34 MXD chronologies over the period 1901-1978, 48% of the total variance of the summer warm-day extreme variability over the period 1901-2006, and 36% of the total variance in the frequency of a summer anticyclonic pattern centered over eastern-central Fennoscandia in the period 1948-2006. The frequency of summer warm-day extremes in Fennoscandia is likely linked to a meridional shift of the northern mid-latitude jet stream. This study shows that the MXD network can be used to infer the variability of past summer warm-day extremes and the frequency of the associated summer anticyclonic circulation pattern over Fennoscandia.

  1. Greater increases in temperature extremes in low versus high income countries

    Science.gov (United States)

    Herold, Nicholas; Alexander, Lisa; Green, Donna; Donat, Markus

    2017-03-01

    It is commonly expected that the world’s lowest income countries will face some of the worst impacts of global warming, despite contributing the least to greenhouse gas emissions. Using global atmospheric reanalyses we show that the world’s lowest income countries are already experiencing greater increases in the occurrence of temperature extremes compared to the highest income countries, and have been for over two decades. Not only are low income countries less able to support mitigation and adaptation efforts, but their typically equatorial location predisposes them to lower natural temperature variability and thus greater changes in the occurrence of temperature extremes with global warming. This aspect of global warming is well known but overlooked in current international climate policy agreements and we argue that it is an important factor in reducing inequity due to climate impacts.

  2. Inelastic X-ray scattering experiments at extreme conditions: high temperatures and high pressures

    Directory of Open Access Journals (Sweden)

    S.Hosokawa

    2008-03-01

    Full Text Available In this article, we review the present status of experimental techniques under extreme conditions of high temperature and high pressure used for inelastic X-ray scattering (IXS experiments of liquid metals, semiconductors, molten salts, molecular liquids, and supercritical water and methanol. For high temperature experiments, some types of single-crystal sapphire cells were designed depending on the temperature of interest and the sample thickness for the X-ray transmission. Single-crystal diamond X-ray windows attached to the externally heated high-pressure vessel were used for the IXS experiment of supercritical water and methanol. Some typical experimental results are also given, and the perspective of IXS technique under extreme conditions is discussed.

  3. Temperature thresholds in assessment of the clinical course of acquired cold contact urticaria: a prospective observational one-year study.

    Science.gov (United States)

    Martinez-Escala, M Estela; Curto-Barredo, Laia; Carnero, Lluïsa; Pujol, Ramon M; Giménez-Arnau, Ana M

    2015-03-01

    Cold contact urticaria is the second most common subtype of physical urticaria. Cold stimulation standardized tests are mandatory to confirm the diagnosis. The aim of this study is to define the utility of determining thresholds (critical time and temperature) in assessment of the clinical course of typical acquired cold contact urticaria. Nineteen adult patients (10 women and 9 men; mean age 45 years) were included in the study and the diagnosis was confirmed with the ice-cube test and TempTest 3.0. Patients were treated continuously for 1 year with 20 mg/day rupatadine (anti-H1). Thresholds measurements were made before and after treatment. Improvements in temperature and critical time thresholds were found in the study sample, demonstrating the efficacy of continuous treatment with rupatadine. In most cases association with a clinical improvement was found. We propose an algorithm for the management of acquired cold contact urticaria based on these results.

  4. Behaviour of cold-formed stainless steel beams at elevated temperatures

    Institute of Scientific and Technical Information of China (English)

    Ju CHEN; Wei-liang JIN

    2008-01-01

    A study of the behaviour of constructional cold-formed stainless steel beams at elevated temperatures was conducted in this paper.An accurate finite element model(FEM)for stainless steel beams was developed using the finite element program ABAQUS.Stainless steel beams having different cross-sections were simulated in this study.The nonlinear FEM was verified against the experimental results.Generally,the developed FEM could accurately simulate the stainless steel beams.Based on the high temperature stainless steel material test results,a parametric study was carried out on stainless steel beams at elevated tem-peratures using the verified FEM.Both high strength stainless steel EN 1.4462 and normal strength stainless steel EN 1.4301 were considered.A total of 42 stainless steel beams were simulated in the parametric study.The effect of temperatures on the behaviour of stainless steel beams was investigated.In addition,a limiting temperature for stainless steel beams was also proposed.

  5. Glycol cold thermal energy storage systems : performance and the effect of varying environment temperature

    Energy Technology Data Exchange (ETDEWEB)

    Bakan, K.; Dincer, I.; Rosen, M.A. [Univ. of Ontario Inst. of Technology, Oshawa, ON (Canada). Faculty of Engineering and Applied Science

    2006-07-01

    This paper examined the effect of varying ambient temperatures on glycol cold thermal energy storage (CTES) systems. When glycol thermal storage is incorporated into a new or existing building, a low temperature chilled-water supply allows the use of low-temperature air distribution and smaller fans and ducts. A reduction and shift in peak electric power demand can be realized through the use of glycol CTES as it permits the storage of night-time electric power. This study investigated the thermodynamic system parameters of: storage temperature; storage heat load; exergy destructions; and energy and exergy efficiencies. A storage tank with a capacity of 150,000 kg was used in the investigation. The air-conditioning cycle was simulated using the commercial software package Engineering Equation Solver (EES). Exergy analyses considered quantities of exergy, energy and mass. It was concluded that the exergy efficiency of the system was approximately 46 per cent less than energy efficiency due to irreversibilities. Results indicated that maximum energy efficiency was 75 per cent, and the corresponding exergy efficiency was 40 per cent for a 50 degrees C ambient air temperature. 13 refs., 5 figs.

  6. Characterization of Future Caribbean Rainfall and Temperature Extremes across Rainfall Zones

    Directory of Open Access Journals (Sweden)

    Natalie Melissa McLean

    2015-01-01

    Full Text Available End-of-century changes in Caribbean climate extremes are derived from the Providing Regional Climate for Impact Studies (PRECIS regional climate model (RCM under the A2 and B2 emission scenarios across five rainfall zones. Trends in rainfall, maximum temperature, and minimum temperature extremes from the RCM are validated against meteorological stations over 1979–1989. The model displays greater skill at representing trends in consecutive wet days (CWD and extreme rainfall (R95P than consecutive dry days (CDD, wet days (R10, and maximum 5-day precipitation (RX5. Trends in warm nights, cool days, and warm days were generally well reproduced. Projections for 2071–2099 relative to 1961–1989 are obtained from the ECHAM5 driven RCM. Northern and eastern zones are projected to experience more intense rainfall under A2 and B2. There is less consensus across scenarios with respect to changes in the dry and wet spell lengths. However, there is indication that a drying trend may be manifest over zone 5 (Trinidad and northern Guyana. Changes in the extreme temperature indices generally suggest a warmer Caribbean towards the end of century across both scenarios with the strongest changes over zone 4 (eastern Caribbean.

  7. Trends in Extremes of Surface Humidity, Temperature, and Summertime Heat Stress in China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the past half century, the mean summertime temperature in China has increased, with nights warm ing more than days. Using surface station observations, we show that the frequency of extreme heat-stress events in China, caused by extremely hot and humid days as well as by heatwaves lasting for a few days, has increased over the period from 1951 to 1994. When humidity is high, hot weather can cause heat stress in humans. The increased heat-stress trend may pose a public health problem.

  8. Sr/Ca ratios in cold-water corals - a 'low-resolution' temperature archive?

    Science.gov (United States)

    Rüggeberg, Andres; Riethdorf, Jan-Rainer; Raddatz, Jacek; López Correa, Matthias; Montagna, Paolo; Dullo, Wolf-Christian; Freiwald, André

    2010-05-01

    One of the basic data to understand global change and past global changes is the measurement and the reconstruction of temperature of marine water masses. E.g. seawater temperature controls the density of seawater and in combination with salinity is the major driving force for the oceans circulation system. Geochemical investigations on cold-water corals Lophelia pertusa and Desmophyllum cristagalli indicated the potential of these organisms as high-resolution archives of environmental parameters from intermediate and deeper water masses (Adkins and Boyle 1997). Some studies tried to use cold-water corals as a high-resolution archive of temperature and salinity (Smith et al. 2000, 2002; Blamart et al. 2005; Lutringer et al. 2005). However, the fractionation of stable isotopes (delta18O and delta13C) and element ratios (Sr/Ca, Mg/Ca, U/Ca) are strongly influenced by vital effects (Shirai et al. 2005; Cohen et al. 2006), and difficult to interpret. Nevertheless, ongoing studies indicate the potential of a predominant temperature dependent fractionation of distinct isotopes and elements (e.g. Li/Ca, Montagna et al. 2008; U/Ca, Mg/Ca, delta18O, Lòpez Correa et al. 2008; delta88/86Sr, Rüggeberg et al. 2008). Within the frame of DFG-Project TRISTAN and Paläo-TRISTAN (Du 129/37-2 and 37-3) we investigated live-collected specimens of cold-water coral L. pertusa from all along the European continental margin (Northern and mid Norwegian shelves, Skagerrak, Rockall and Porcupine Bank, Galicia Bank, Gulf of Cadiz, Mediterranean Sea). These coral samples grew in waters characterized by temperatures between 6°C and 14°C. Electron Microprobe investigations along the growth direction of individual coral polyps were applied to determine the relationship between the incorporation of distinct elements (Sr, Ca, Mg, S). Cohen et al. (2006) showed for L. pertusa from the Kosterfjord, Skagerrak, that ~25% of the coral's Sr/Ca ratio is related to temperature, while 75% are influenced

  9. Improving the Health Forecasting Alert System for Cold Weather and Heat-Waves In England: A Proof-of-Concept Using Temperature-Mortality Relationships.

    Directory of Open Access Journals (Sweden)

    Giacomo Masato

    Full Text Available In this study a prototype of a new health forecasting alert system is developed, which is aligned to the approach used in the Met Office's (MO National Severe Weather Warning Service (NSWWS. This is in order to improve information available to responders in the health and social care system by linking temperatures more directly to risks of mortality, and developing a system more coherent with other weather alerts. The prototype is compared to the current system in the Cold Weather and Heatwave plans via a case-study approach to verify its potential advantages and shortcomings.The prototype health forecasting alert system introduces an "impact vs likelihood matrix" for the health impacts of hot and cold temperatures which is similar to those used operationally for other weather hazards as part of the NSWWS. The impact axis of this matrix is based on existing epidemiological evidence, which shows an increasing relative risk of death at extremes of outdoor temperature beyond a threshold which can be identified epidemiologically. The likelihood axis is based on a probability measure associated with the temperature forecast. The new method is tested for two case studies (one during summer 2013, one during winter 2013, and compared to the performance of the current alert system.The prototype shows some clear improvements over the current alert system. It allows for a much greater degree of flexibility, provides more detailed regional information about the health risks associated with periods of extreme temperatures, and is more coherent with other weather alerts which may make it easier for front line responders to use. It will require validation and engagement with stakeholders before it can be considered for use.

  10. Improving the Health Forecasting Alert System for Cold Weather and Heat-Waves In England: A Proof-of-Concept Using Temperature-Mortality Relationships.

    Science.gov (United States)

    Masato, Giacomo; Bone, Angie; Charlton-Perez, Andrew; Cavany, Sean; Neal, Robert; Dankers, Rutger; Dacre, Helen; Carmichael, Katie; Murray, Virginia

    2015-01-01

    In this study a prototype of a new health forecasting alert system is developed, which is aligned to the approach used in the Met Office's (MO) National Severe Weather Warning Service (NSWWS). This is in order to improve information available to responders in the health and social care system by linking temperatures more directly to risks of mortality, and developing a system more coherent with other weather alerts. The prototype is compared to the current system in the Cold Weather and Heatwave plans via a case-study approach to verify its potential advantages and shortcomings. The prototype health forecasting alert system introduces an "impact vs likelihood matrix" for the health impacts of hot and cold temperatures which is similar to those used operationally for other weather hazards as part of the NSWWS. The impact axis of this matrix is based on existing epidemiological evidence, which shows an increasing relative risk of death at extremes of outdoor temperature beyond a threshold which can be identified epidemiologically. The likelihood axis is based on a probability measure associated with the temperature forecast. The new method is tested for two case studies (one during summer 2013, one during winter 2013), and compared to the performance of the current alert system. The prototype shows some clear improvements over the current alert system. It allows for a much greater degree of flexibility, provides more detailed regional information about the health risks associated with periods of extreme temperatures, and is more coherent with other weather alerts which may make it easier for front line responders to use. It will require validation and engagement with stakeholders before it can be considered for use.

  11. The Effect of Local Heat and Cold Therapy on the Intraarticular and Skin Surface Temperature of the Knee

    NARCIS (Netherlands)

    Oosterveld, F.G.J.; Rasker, J.J.; Jacobs, J.W.G.; Overmars, H.J.A.

    1992-01-01

    Objective. To evaluate the effects of local application of ice chips, ligno-paraffin, short-wave diathermy, and nitrogen-cold air on skin and intraarticular temperature. Methods. Forty-two healthy subjects were divided into 4 treatment groups. A temperature probe was inserted into the knee joint ca

  12. Selection of Psychrotolerant Microorganisms Producing Cold-Active Pectinases for Biotechnological Processes at Low Temperature

    Directory of Open Access Journals (Sweden)

    María S. Cabeza

    2011-01-01

    Full Text Available In winemaking, low temperatures are favourable for the production and retention of flavour and colour components, requiring the use of cold-active enzymes. For this reason, 'psychrotolerant' microorganisms have been isolated and selected based on their ability to produce pectinolytic enzymes with satisfactory activity at low temperatures. Different mature grape varieties with designation of origin were sampled from the region of San Rafael (Mendoza, Argentina, and pectinolytic bacterial, fungal and yeast strains were isolated. The pectinolytic activity was measured by cup-plate assay, quantification of released reducing sugars and viscosity reduction of pectin solution. Two bacteria (Bacillus sp. SC-G and SC-H and two yeast strains were selected for their good pectinase activity at low temperatures. Among them, the strain with the highest activity, Bacillus sp. SC-H, was selected. According to their 16S rRNA profiles, Bacillus sp. SC-G and SC-H can be classified as members of Bacillus subtilis. Among the assayed techniques, the rotary evaporation was found to be the most appropriate to obtain enzymatic extracts with highest activity. The optimal conditions for the enzymatic activity were 30 °C and pH=5.0 for the concentrated extract, and 45 °C and pH=6.0 for the filtered supernatant. The concentrated extract presented good activity at 3 °C, confirming that it was a cold-active enzyme. Natural extraction and enzymatic preparation were used to extract pigments and polyphenols from Malbec grapes. Better results were obtained for the enzymatic extract with regard to index, shade, CIELab coordinates, CIELab colour differences and polyphenols (measured using Folin-Ciocalteu.

  13. Climate Change: A New Metric to Measure Changes in the Frequency of Extreme Temperatures using Record Data

    Science.gov (United States)

    Munasinghe, L.; Jun, T.; Rind, D. H.

    2012-01-01

    Consensus on global warming is the result of multiple and varying lines of evidence, and one key ramification is the increase in frequency of extreme climate events including record high temperatures. Here we develop a metric- called "record equivalent draws" (RED)-based on record high (low) temperature observations, and show that changes in RED approximate changes in the likelihood of extreme high (low) temperatures. Since we also show that this metric is independent of the specifics of the underlying temperature distributions, RED estimates can be aggregated across different climates to provide a genuinely global assessment of climate change. Using data on monthly average temperatures across the global landmass we find that the frequency of extreme high temperatures increased 10-fold between the first three decades of the last century (1900-1929) and the most recent decade (1999-2008). A more disaggregated analysis shows that the increase in frequency of extreme high temperatures is greater in the tropics than in higher latitudes, a pattern that is not indicated by changes in mean temperature. Our RED estimates also suggest concurrent increases in the frequency of both extreme high and extreme low temperatures during 2002-2008, a period when we observe a plateauing of global mean temperature. Using daily extreme temperature observations, we find that the frequency of extreme high temperatures is greater in the daily minimum temperature time-series compared to the daily maximum temperature time-series. There is no such observable difference in the frequency of extreme low temperatures between the daily minimum and daily maximum.

  14. The evolution of temperature extremes in the Gaspé Peninsula, Quebec, Canada (1974-2013)

    Science.gov (United States)

    Fortin, Guillaume; Acquaotta, Fiorella; Fratianni, Simona

    2016-07-01

    The majority of natural hazards that affect Canadian territory are the result of extreme climate and weather conditions. Among these weather hazards, some can be calculated from the application of thresholds for minimum and maximum temperatures at a daily or monthly timescale. These thermal indices allowed the prediction of extreme conditions that may have an impact on the human population by affecting, for example, health, agriculture, and water resources. In this article, we discuss the methods used (RHtestsV4, SPLIDHOM, ClimPACT) then describe the steps followed to calculate the indices, including how we dealt with the problem of missing data and the necessity to identify a common methodology to analyze the time series. We also present possible solutions for ensuring the quality of meteorological data. We then present an overview of the results, namely the main trends and variability of extreme temperature for seven stations located in the Gaspé Peninsula from 1974 to 2013. Our results indicate some break points in time series and positive trends for most indices related to the rise of the temperatures but indicate a negative trend for the indices related to low temperatures for most stations during the study period.

  15. Spatiotemporal variations of extreme low temperature for emergency transport: a nationwide observational study

    Science.gov (United States)

    Onozuka, Daisuke; Hagihara, Akihito

    2016-12-01

    Although recent studies have investigated the effect of extreme heat on emergency transport, few have investigated the spatiotemporal variations of extreme low temperature for emergency transport on a national scale. Data pertaining to emergency ambulance transport and weather variation in the 47 prefectures of Japan between 2007 and 2010 were obtained. Nonlinear and delayed relationships between temperature and morbidity were assessed using a two-stage analysis. First, a Poisson regression analysis allowing for overdispersion in a distributed lag nonlinear model was used to estimate the prefecture-specific effects of temperature on morbidity. Second, a multivariate meta-analysis was applied to pool estimates on a national level. Of 15,868,086 emergency transports over the study period, 5,375,621 emergency transports were reported during the winter months (November through February). The overall cumulative relative risk (RR) at the first percentile vs. the minimum morbidity percentile was 1.24 (95 % CI = 1.15-1.34) for all causes, 1.50 (95 % CI = 1.30-1.74) for cardiovascular diseases, and 1.59 (95 % CI = 1.33-1.89) for respiratory diseases. There were differences in the temporal variations between extreme low temperature and respiratory disease morbidity. Spatial variation between prefectures was observed for all causes (Cochran Q test, p social and environmental factors, which can be responsible for spatial heterogeneity between prefectures.

  16. Time series requirements and trends of temperature and precipitation extremes over Italy

    Science.gov (United States)

    Fioravanti, Guido; Desiato, Franco; Fraschetti, Piero; Perconti, Walter; Piervitali, Emanuela

    2013-04-01

    Extreme climate events have strong impacts on society and economy; accordingly,the knowledge of their trends on long period is crucial for the definition and implementation of a national adaptation strategy to climate change. The Research Programme on Climate Variability and Predictability (CLIVAR) identified a set of temperature and precipitation indices suited to investigate variability and trends of climate extremes. It is well known that extreme indices calculation is more demanding than first and second order statistics are: daily temperature and precipitation data are required and strict constrains in terms of continuity and completeness must be met. In addition, possible dishomogeneities affecting time series must be identified and adjusted before indices calculation. When metadata are not available, statistical methods can provide scientist a relevant support for homogeneity check; however, ad-hoc decision criteria (sometimes subjective) must be applied whenever contradictory results characterize different statistical homogeneity tests. In this work, a set of daily (minimum and maximum) temperature and precipitation time series for the period 1961-2011 were selected in order to guarantee a quite uniform spatial distribution of the stations over the Italian territory and according to the afore-said continuity and completeness criteria. Following the method described by Vincent, the homogeneity check of temperature time series was run at annual level. Two well-documented tests were employed (F-test and T-test), both implemented in the free R-package RHtestV3. The Vincent method was also used for a further investigation of time series homogeneity. Temperature dishomogeneous series were discarded. For precipitation series, no homogeneity check was run. The selected series were employed at daily level to calculate a reliable set of extreme indices. For each station, a linear model was employed for indices trend estimation. Finally, single station results were

  17. Seasonal trends in precipitation and surface air temperature extremes in mainland Portugal, 1941-2007

    Science.gov (United States)

    de Lima, M. I. P.; Santo, F. E.; Ramos, A. M.

    2012-04-01

    Several climate models predict, on a global scale, modifications in climate variables that are expected to have impact on society and the environment. The concern is on changes in the variability of processes, the mean and extreme events (maximum and minimum). To explore recent changes in precipitation and near surface air temperature extremes in mainland Portugal, we have inspected trends in time series of specific indices defined for daily data. These indices were recommended by the Commission for Climatology/Climate Variability and Predictability (CCl/CLIVAR) Working Group on Climate Change Detection, and include threshold indices, probability indices, duration indices and other indices. The precipitation and air temperature data used in this study are from, respectively, 57 and 23 measuring stations scattered across mainland Portugal, and cover the periods 1941-2007, for precipitation, and 1941-2006, for temperature. The study focuses on changes at the seasonal scale. Strong seasonality is one of the main features of climate in mainland Portugal. Intensification of the seasonality signal across the territory, particularly in the more sensitive regions, might contribute to endanger already fragile soil and water resources and ecosystems, and the local environmental and economic sustainability. Thus, the understanding of variations in the intensity, frequency and duration of extreme precipitation and air temperature events at the intra-annual scale is particularly important in this geographical area. Trend analyses were conducted over the full period of the records and for sub-periods, exploring patterns of change. Results show, on the one hand, regional differences in the tendency observed in the time series analysed; and, on the other hand, that although trends in annual indices are in general not statistically significant, there are sometimes significant changes over time in the data at the seasonal scale that point out to an increase in the already existing

  18. Thermographic Evaluation of the Hands of Pig Slaughterhouse Workers Exposed to Cold Temperatures

    Science.gov (United States)

    Ramos, Eliane

    2017-01-01

    Brazil was rated the fourth leading producer and exporter of pork meat in the world. The aim of this study was to evaluate the temperature of the hands of pig slaughterhouse workers and its relation to the thermal sensation of the hands and the use of a cutting tool. The study included 106 workers in a pig slaughterhouse. An infrared camera FlirThermaCAM E320 (Flir Systems, Wilsonville, OR, USA) was used to collect the images of the dorsal and palmar surfaces of both hands. A numerical scale was used to obtain the thermal sensation. Chi-square test, Pearson correlation and Student’s t test or Wilcoxon were used (p ≤ 0.05). The majority of workers felt cold in the hands (66%) and workers who used the knife felt the coldest. There was an association between the thermal sensation and the use of knife (p = 0.001). Workers who used the tool showed correlation between the thermal sensation and the temperatures of the left fingers, with a difference between the temperatures of the right and left hands of those who used the knife (p ≤ 0.05). The hands (left) that manipulated the products presented the lowest temperatures. Findings indicate that employers of pig slaughterhouses should provide gloves with adequate thermal insulation to preserve the health of workers’ hands.

  19. In situ observation and measurement of composites subjected to extremely high temperature

    Science.gov (United States)

    Fang, Xufei; Yu, Helong; Zhang, Guobing; Su, Hengqiang; Tang, Hongxiang; Feng, Xue

    2014-03-01

    In this work, we develop an instrument to study the ablation and oxidation process of materials such as C/SiC (carbon fiber reinforced silicon carbide composites) and ultra-high temperature ceramic in extremely high temperature environment. The instrument is integrated with high speed cameras with filtering lens, infrared thermometers and water vapor generator for image capture, temperature measurement, and humid atmosphere, respectively. The ablation process and thermal shock as well as the temperature on both sides of the specimen can be in situ monitored. The results show clearly the dynamic ablation and liquid oxide flowing. In addition, we develop an algorithm for the post-processing of the captured images to obtain the deformation of the specimens, in order to better understand the behavior of the specimen subjected to high temperature.

  20. Some traits of low temperature germplasm wheat under extremely unfavorable weather conditions

    Institute of Scientific and Technical Information of China (English)

    张嵩午; 王长发; 冯佰利; 苗芳; 周春菊; 张荣萍

    2001-01-01

    Through a long-term observation on the canopy temperature and some traits of wheat the temperature germplasm of wheat was found to result in the wheats having either a high or a low plant temperature. Under normal weather conditions, the wheat having a low temperature germplasm (LTG) demonstrated several advantageous physiologi-cal and agronomic traits than those having a high temperature germplasm (HTG). Under the extremely unfavorableweather conditions, such as rainy weather or severe drought, LTG wheat still could maintain its superiority to HTG wheat in physiological and agronomic traits including leaf functional duration, chlorophyll content, malondialdehyde content, transpiration rate, net photosynthesis rate, root vitality and kernel plumpness. The wide adaptability of LTG wheat to awide range of meteoro-ecological conditions could provide a valuable germplasm in breeding of good strains with broad-spectrum stress resistance.

  1. Solar Orbiter- Solar Array- Thermal Design for an Extreme Temperature Mission

    Science.gov (United States)

    Muller, Jens; Paarmann, Carola; Lindner, Anton; Kreutz, Martin; Oberhuttinger, Carola; Costello, Ian; Icardi, Lidia

    2014-08-01

    The Solar Orbiter mission is an interdisciplinary mission to the sun, carried out by ESA in collaboration with NASA. The spacecraft will approach the sun close to 0.28 AU. At this distance, the solar array has to be operated under high solar array inclination angles to limit the temperatures to a maximum qualification temperature of 200°C for the photo voltaic assembly (PVA). Nevertheless, extreme temperatures appear at specific locations of the solar array which require purpose-built temperature protection measures. A very specific thermal protection is needed to keep the PVA and its supporting structures within the qualified temperature range and simultaneously minimize the thermal flux into the spacecraft.This paper describes the Solar Orbiter solar array design in general and its specific thermal design in particular. It describes the interdisciplinary steps between thermal- and mechanical analysis as well as design engineering necessary to result to the different shielding methods.

  2. Susceptibility to mortality related to temperature and heat and cold wave duration in the population of Stockholm County, Sweden

    Directory of Open Access Journals (Sweden)

    Joacim Rocklöv

    2014-03-01

    Full Text Available Background: Ambient temperatures can cause an increase in mortality. A better understanding is needed of how health status and other factors modify the risk associated with high and low temperatures, to improve the basis of preventive measures. Differences in susceptibility to temperature and to heat and cold wave duration are relatively unexplored. Objectives: We studied the associations between mortality and temperature and heat and cold wave duration, stratified by age and individual and medical factors. Methods: Deaths among all residents of Stockholm County between 1990 and 2002 were linked to discharge diagnosis data from hospital admissions, and associations were examined using the time stratified case-crossover design. Analyses were stratified by gender, age, pre-existing disease, country of origin, and municipality level wealth, and adjusted for potential confounding factors. Results: The effect on mortality by heat wave duration was higher for lower ages, in areas with lower wealth, for hospitalized patients younger than age 65. Odds were elevated among females younger than age 65, in groups with a previous hospital admission for mental disorders, and in persons with previous cardiovascular disease. Gradual increases in summer temperatures were associated with mortality in people older than 80 years, and with mortality in groups with a previous myocardial infarction and with chronic obstructive pulmonary disease (COPD in the population younger than 65 years. During winter, mortality was associated with a decrease in temperature particularly in men and with the duration of cold spells for the population older than 80. A history of hospitalization for myocardial infarction increased the odds associated with cold temperatures among the population older than 65. Previous mental disease or substance abuse increased the odds of death among the population younger than 65. Conclusion: To increase effectiveness, we suggest preventive efforts

  3. Climate changes in temperature and precipitation extremes in an alpine grassland of Central Asia

    Science.gov (United States)

    Hu, Zengyun; Li, Qingxiang; Chen, Xi; Teng, Zhidong; Chen, Changchun; Yin, Gang; Zhang, Yuqing

    2016-11-01

    The natural ecosystem in Central Asia is sensitive and vulnerable to the arid and semiarid climate variations, especially the climate extreme events. However, the climate extreme events in this area are still unclear. Therefore, this study analyzed the climate variability in the temperature and precipitation extreme events in an alpine grassland (Bayanbuluk) of Central Asia based on the daily minimum temperature, daily maximum temperature, and daily precipitation from 1958 to 2012. Statistically significant ( p < 0.01) increasing trends were found in the minimum temperature, maximum temperature at annual, and seasonal time scales except the winter maximum temperature. In the seasonal changes, the winter temperature had the largest contribution to the annual warming. Further, there appeared increasing trends for the warm nights and the warm days and decreasing trends for the cool nights and the cool days at a 99 % confidence level. These trends directly resulted in an increasing trend for the growing season length (GSL) which could have positively influence on the vegetation productivity. For the precipitation, it displayed an increasing trend for the annual precipitation although it was not significant. And the summer precipitation had the same variations as the annual precipitation which indicated that the precipitation in summer made the biggest contribution to the annual precipitation than the other three seasons. The winter precipitation had a significant increasing trend (1.49 mm/10a) and a decreasing trend was found in spring. We also found that the precipitation of the very wet days mainly contributes to the annual precipitation with the trend of 4.5 mm/10a. The maximum 1-day precipitation and the heavy precipitation days only had slight increasing trend. A sharp decreasing trend was found before the early 1980s, and then becoming increase for the above three precipitation indexes. The climate experienced a warm-wet abrupt climate change in the 1980s

  4. Spatial distribution of temperature extremes changes in Poland in 21st century

    Science.gov (United States)

    Jędruszkiewicz, Joanna

    2013-04-01

    There is a general agreement that changes in the frequency or intensity of extreme weather and climate events have profound impacts on both human society and the economy. In the recent years a numerous weather events have affected human health and caused enormous economic losses. A long-lasting heat waves influence society far more than rare occurred extreme high temperature. On the other hand a winter warming and frequent exceedance of 0°C during winter will be disruptive i.e. for the wheel transport and roads condition in Poland. This work is focused on the study of the spatial diversity of minimum and maximum temperature in 21st century in Poland. Firstly the shift in distribution (PDF) and cumulative distribution (CDF) of the daily maximum temperature in summer and minimum temperature in winter between control and scenario periods was compared among different part of the country. Secondly the changes in the characteristic percentiles of the temperature extremes were analyzed. Furthermore the spatial changes in the duration and frequency of the heat waves in Poland were studied. Moreover the future prediction of changes in characteristic days as hot days (Tmax≥30°C), summer days (Tmax≥25°C), tropical nights (Tmin≥20°C), frost days (Tmin<0°C), etc. were spatially compared. The diurnal temperature range (DTR) is expected to change remarkably in 21st century depending on the area of Poland. The daily minimum and maximum 2-meter temperature date have been obtained from seven different regional climate models and corrected by quintile mapping method afterwards. The Polish station data for the control period have been gained from the Institute of Meteorology and Water Management, National Research Institute.

  5. Multi-decadal Surface Temperature Trends and Extremes at Arctic Stations

    Science.gov (United States)

    Uttal, T.; Makshtas, A.

    2015-12-01

    The Arctic region is considered to be one where global temperatures are changing the most quickly; a number of factors make it the region where an accurate determination of surface temperature is the most difficult to measure or estimate. In developing a pan-Arctic perspective on Arctic in-situ temperature variability, several issues must be addressed including accounting for the different lengths of temperature records at different locations when comparing trends, accounting for the steep latitudinal controls on 'seasonal' trends, considering the often significant variability between different (sometimes a multitude) of temperature measurements made in the vicinity of a single station, and loss of detail information when data is ingested in a global archives or interpolated into gridded data sets. The International Arctic Systems for Observing the Atmosphere (www.iasoa.org) is an internationally networked consortium of facilities that measure a wide range of meteorological and climate relevant parameters; temperature is the most fundamental of these parameters. Many of the observatories have the longest temperature records in the Arctic region including Barrow, Alaska (114 years), Tiksi, Russia (83 years), and Eureka, Canada (67 years). Using the IASOA data sets a detailed analysis is presented of temperature trends presented as a function of the beginning date from which the trend is calculated, seasonal trends considered in the context of the extreme Arctic solar ephemeris, and the variability in occurrence of annual extreme temperature events. At the Tiksi observatory, a complete record is available of 3-hourly temperatures 1932 to present that was constructed through digitization of decades of written records. This data set is used to investigate if calculated trends and variabilities are consistent with those calculated from daily minimum and maximum values archived by the NOAA National Centers for Environmental Information Global Historical Climatology

  6. Design of Cold-Formed Steel Screw Connections with Gypsum Sheathing at Ambient and Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2016-09-01

    Full Text Available Load-bearing cold-formed steel (CFS walls sheathed with double layers of gypsum plasterboard on both sides have demonstrated good fire resistance and attracted increasing interest for use in mid-rise CFS structures. As the main connection method, screw connections between CFS and gypsum sheathing play an important role in both the structural design and fire resistance of this wall system. However, studies on the mechanical behavior of screw connections with double-layer gypsum sheathing are still limited. In this study, 200 monotonic tests of screw connections with single- or double-layer gypsum sheathing at both ambient and elevated temperatures were conducted. The failure of screw connections with double-layer gypsum sheathing in shear was different from that of single-layer gypsum sheathing connections at ambient temperature, and it could be described as the breaking of the loaded sheathing edge combined with significant screw tilting and the loaded sheathing edge flexing fracture. However, the screw tilting and flexing fracture of the loaded sheathing edge gradually disappear at elevated temperatures. In addition, the influence of the loaded edge distance, double-layer sheathing and elevated temperatures is discussed in detail with clear conclusions. A unified design formula for the shear strength of screw connections with gypsum sheathing is proposed for ambient and elevated temperatures with adequate accuracy. A simplified load–displacement model with the post-peak branch is developed to evaluate the load–displacement response of screw connections with gypsum sheathing at ambient and elevated temperatures.

  7. Minimum extreme temperature in the gulf of mexico: is there a connection with solar activity?

    Science.gov (United States)

    Maravilla, D.; Mendoza, B.; Jauregui, E.

    Minimum extreme temperature ( MET) series from several meteorological stations of the Gulf of Mexico are spectrally analyzed using the Maximum Entrophy Method. We obtained periodicities similar to those found in the sunspot number, the magnetic solar cycle, comic ray fluxes and geomagnetic activity which are modulated by solar activity. We suggested that the solar signal is perhaps present in the MET record of this region of Mexico.

  8. Ingestion of a cold temperature/menthol beverage increases outdoor exercise performance in a hot, humid environment.

    Directory of Open Access Journals (Sweden)

    Than Tran Trong

    Full Text Available A recent laboratory study demonstrated that the ingestion of a cold/menthol beverage improved exercise performance in a hot and humid environment during 20 km of all-out cycling. Therefore, the aim of this study was to determine whether the ingestion of cold water/ice-slurry with menthol would improve performance in hot and humid outdoor conditions.Ten trained males completed three trials of five blocks consisting of 4-km cycling and 1.5-km running. During warm-up, every block and recovery, the athletes drank 190 ml of aromatized (i.e., with 0.05 mL of menthol beverage at three temperatures: Neutral (ambient temperature (28.7°C±0. 5°C, Cold (3.1°C±0.6°C or Ice-slurry (0.17°C±0.07°C. Trial time, core temperature (Tco, heart rate (HR, rate of perceived exertion (RPE, thermal sensation (TS and thermal comfort (TC were assessed.Ice-slurry/menthol increased performance by 6.2% and 3.3% compared with neutral water/menthol and cold water/menthol, respectively. No between-trial differences were noted for Tco, HR, RPE, TC and TS was lower with ice-slurry/menthol and cold water/menthol compared with neutral water/menthol.A low drink temperature combined with menthol lessens the performance decline in hot/humid outdoor conditions (i.e., compared with cold water alone. Performances were better with no difference in psycho-physiological stress (Tco, HR and RPE between trials. The changes in perceptual parameters caused by absorbing a cold/menthol beverage reflect the psychological impact. The mechanism leading to these results seems to involve brain integration of signals from physiological and psychological sources.

  9. Cross-tolerance and cross-talk in the cold: relating low temperatures to desiccation and immune stress in insects.

    Science.gov (United States)

    Sinclair, Brent J; Ferguson, Laura V; Salehipour-shirazi, Golnaz; MacMillan, Heath A

    2013-10-01

    Multiple stressors, both abiotic and biotic, often are experienced simultaneously by organisms in nature. Responses to these stressors may share signaling pathways ("cross-talk") or protective mechanisms ("cross-tolerance"). Temperate and polar insects that must survive the winter experience low temperatures accompanied by additional abiotic stressors, such as low availability of water. Cold and desiccation have many similar effects at a cellular level, and we present evidence that the cellular mechanisms that protect against cold stress also protect against desiccation, and that the responses to cold and dehydration likely evolved as cross-tolerance. By contrast, there are several lines of evidence suggesting that low temperature stress elicits an upregulation of immune responses in insects (and vice versa). Because there is little mechanistic overlap between cold stress and immune stress at the cellular level, we suggest that this is cross-talk. Both cross-talk and cross-tolerance may be adaptive and likely evolved in response to synchronous stressors; however, we suggest that cross-talk and cross-tolerance may lead to different responses to changes in the timing and severity of multiple stress interactions in a changing world. We present a framework describing the potentially different responses of cross-tolerance and cross-talk to a changing environment and describe the nature of these impacts using interaction of cold-desiccation and cold-immunity in overwintering insects as an example.

  10. Temperature and Relative Humidity Inside Trailers During Finishing Pig Loading and Transport in Cold and Mild Weather

    Directory of Open Access Journals (Sweden)

    John McGlone

    2014-09-01

    Full Text Available The effect of bedding levels and trailer compartment on internal trailer temperature and relative humidity (RH during loading and transport of finishing pigs was evaluated in cold and mild weather. Three levels of bedding were used in each experiment: 0.6 m3, 1.2 m3, and 2.4 m3. In mild weather, internal temperatures were lower when 1.2 m3 or 2.4 m3 of bedding were used during loading and transport compared to 0.6 m3 (P < 0.05. Internal trailer temperature increased in a quadratic fashion in the top front compartment when 1.2 m3 was used (P < 0.05, and in a linear fashion in the top rear compartment when 2.4 m3 were used in cold weather (P < 0.05. In mild weather, temperature increased linearly in the top front compartment with heavy bedding levels. Relative humidity increased in a linear fashion in the top front compartment with 0.6 m3, bottom front with 1.2 m3, and top front with 1.2 m3 in cold weather (P < 0.05. In general, temperature and RH increased as bedding levels increased in both cold and mild temperatures. Excess bedding can absorb more moisture, resulting in transport loss and decreased animal welfare.

  11. Trends and periodicity of daily temperature and precipitation extremes during 1960-2013 in Hunan Province, central south China

    Science.gov (United States)

    Chen, Ajiao; He, Xinguang; Guan, Huade; Cai, Yi

    2017-02-01

    In this study, the trends and periodicity in climate extremes are examined in Hunan Province over the period 1960-2013 on the basis of 27 extreme climate indices calculated from daily temperature and precipitation records at 89 meteorological stations. The results show that in the whole province, temperature extremes exhibit a warming trend with more than 50% stations being statistically significant for 7 out of 16 temperature indices, and the nighttime temperature increases faster than the daytime temperature at the annual scale. The changes in most extreme temperature indices show strongly coherent spatial patterns. Moreover, the change rates of almost all temperature indices in north Hunan are greater than those of other regions. However, the statistically significant changes in indices of extreme precipitation are observed at fewer stations than in extreme temperature indices, forming less spatially coherent patterns. Positive trends in indices of extreme precipitation show that the amount and intensity of extreme precipitation events are generally increasing in both annual and seasonal scales, whereas the significant downward trend in consecutive wet days indicates that the precipitation becomes more even over the study period. Analysis of changes in probability distributions of extreme indices for 1960-1986 and 1987-2013 also demonstrates a remarkable shift toward warmer condition and increasing tendency in the amount and intensity of extreme precipitation during the past decades. The variations in extreme climate indices exhibit inconstant frequencies in the wavelet power spectrum. Among the 16 temperature indices, 2 of them show significant 1-year periodic oscillation and 7 of them exhibit significant 4-year cycle during some certain periods. However, significant periodic oscillations can be found in all of the precipitation indices. Wet-day precipitation and three absolute precipitation indices show significant 1-year cycle and other seven provide

  12. Refining multi-model projections of temperature extremes by evaluation against land-atmosphere coupling diagnostics

    Science.gov (United States)

    Sippel, Sebastian; Zscheischler, Jakob; Mahecha, Miguel D.; Orth, Rene; Reichstein, Markus; Vogel, Martha; Seneviratne, Sonia I.

    2017-05-01

    The Earth's land surface and the atmosphere are strongly interlinked through the exchange of energy and matter. This coupled behaviour causes various land-atmosphere feedbacks, and an insufficient understanding of these feedbacks contributes to uncertain global climate model projections. For example, a crucial role of the land surface in exacerbating summer heat waves in midlatitude regions has been identified empirically for high-impact heat waves, but individual climate models differ widely in their respective representation of land-atmosphere coupling. Here, we compile an ensemble of 54 combinations of observations-based temperature (T) and evapotranspiration (ET) benchmarking datasets and investigate coincidences of T anomalies with ET anomalies as a proxy for land-atmosphere interactions during periods of anomalously warm temperatures. First, we demonstrate that a large fraction of state-of-the-art climate models from the Coupled Model Intercomparison Project (CMIP5) archive produces systematically too frequent coincidences of high T anomalies with negative ET anomalies in midlatitude regions during the warm season and in several tropical regions year-round. These coincidences (high T, low ET) are closely related to the representation of temperature variability and extremes across the multi-model ensemble. Second, we derive a land-coupling constraint based on the spread of the T-ET datasets and consequently retain only a subset of CMIP5 models that produce a land-coupling behaviour that is compatible with these benchmark estimates. The constrained multi-model simulations exhibit more realistic temperature extremes of reduced magnitude in present climate in regions where models show substantial spread in T-ET coupling, i.e. biases in the model ensemble are consistently reduced. Also the multi-model simulations for the coming decades display decreased absolute temperature extremes in the constrained ensemble. On the other hand, the differences between projected

  13. Refining multi-model projections of temperature extremes by evaluation against land–atmosphere coupling diagnostics

    Directory of Open Access Journals (Sweden)

    S. Sippel

    2017-05-01

    Full Text Available The Earth's land surface and the atmosphere are strongly interlinked through the exchange of energy and matter. This coupled behaviour causes various land–atmosphere feedbacks, and an insufficient understanding of these feedbacks contributes to uncertain global climate model projections. For example, a crucial role of the land surface in exacerbating summer heat waves in midlatitude regions has been identified empirically for high-impact heat waves, but individual climate models differ widely in their respective representation of land–atmosphere coupling. Here, we compile an ensemble of 54 combinations of observations-based temperature (T and evapotranspiration (ET benchmarking datasets and investigate coincidences of T anomalies with ET anomalies as a proxy for land–atmosphere interactions during periods of anomalously warm temperatures. First, we demonstrate that a large fraction of state-of-the-art climate models from the Coupled Model Intercomparison Project (CMIP5 archive produces systematically too frequent coincidences of high T anomalies with negative ET anomalies in midlatitude regions during the warm season and in several tropical regions year-round. These coincidences (high T, low ET are closely related to the representation of temperature variability and extremes across the multi-model ensemble. Second, we derive a land-coupling constraint based on the spread of the T–ET datasets and consequently retain only a subset of CMIP5 models that produce a land-coupling behaviour that is compatible with these benchmark estimates. The constrained multi-model simulations exhibit more realistic temperature extremes of reduced magnitude in present climate in regions where models show substantial spread in T–ET coupling, i.e. biases in the model ensemble are consistently reduced. Also the multi-model simulations for the coming decades display decreased absolute temperature extremes in the constrained ensemble. On the other hand

  14. Extremes temperatures and enthalpy in Finland and Sweden in a changing climate

    Energy Technology Data Exchange (ETDEWEB)

    Venaelaeinen, A.; Saku, S.; Jylhae, K. (Finnish Meteorological Institute (Finland)); Nikulin, G.; Kjellstroem, E.; Baerring, L. (Swedish Meteorological Institute (Sweden))

    2009-06-15

    Though risks caused by harsh weather conditions are taken into account in the planning of nuclear power plants, some exceptional weather events or combination of different events may prevent normal power operation and simultaneously endanger safe shutdown of the plant. Extreme weather events could influence, for example, the external power grid connection, emergency diesel generators (blockage of air intakes), ventilation and cooling of electric and electronics equipment rooms and the seawater intake. Due to the influence of an intensified greenhouse effect the climate is changing rapidly during the coming decades and this change is expected to have an influence also on the occurrence of extreme weather events. In this report we have examined extreme temperatures. Enthalpy is a parameter that combines air temperature and air humidity and it is used in the design of air conditioning systems. Therefore, we have included also return levels of enthalpy in our analysis. The influence of climate change on extreme temperatures is analysed based on regional climate model simulations. The reoccurrence times of high temperatures combined with high air humidity was analysed based on measurements made at five Finnish and three Swedish meteorological stations. Based on the observational records we find the 10 year return level of daily maximum temperature to be around 32 deg. C and the 100 year return level around 35 deg. C. If we look the return levels of warm and humid conditions then for example in Helsinki the 10 year return level of one week mean temperature in case mean air humidity is above 80% is 20.1 deg. C. The 10 year return level of daily maximum enthalpy is around 60 kJ/kg and the 100 year return level almost 70 kJ/kg. According to the climate model simulations the largest increase of 50-year return level of daily maximum temperature is found in southern Sweden and south-western Finland. By the end of this century the increase can be 3-5 deg. C. The largest change

  15. Probing the local, electronic and magnetic structure of matter under extreme conditions of temperature and pressure

    DEFF Research Database (Denmark)

    Torchio, R.; Boccato, S.; Cerantola, V.;

    2016-01-01

    In this paper we present recent achievements in the field of investigation of the local, electronic and magnetic structure of the matter under extreme conditions of pressure and temperature. These results were obtained thanks to the coupling of a compact laser heating system to the energy......-dispersive XAS technique available on the ID24 beamline at the ESRF synchrotron. The examples chosen concern the melting and the liquid structure of 3d metals and alloys under high pressures (HPs) and the observation of temperature-induced spin crossover in FeCO3 at HP....

  16. Cold start dynamics and temperature sliding observer design of an automotive SOFC APU

    Science.gov (United States)

    Lin, Po-Hsu; Hong, Che-Wun

    This paper presents a dynamic model for studying the cold start dynamics and observer design of an auxiliary power unit (APU) for automotive applications. The APU is embedded with a solid oxide fuel cell (SOFC) stack which is a quiet and pollutant-free electric generator; however, it suffers from slow start problem from ambient conditions. The SOFC APU system equips with an after-burner to accelerate the start-up transient in this research. The combustion chamber burns the residual fuel (and air) left from the SOFC to raise the exhaust temperature to preheat the SOFC stack through an energy recovery unit. Since thermal effect is the dominant factor that influences the SOFC transient and steady performance, a nonlinear real-time sliding observer for stack temperature was implemented into the system dynamics to monitor the temperature variation for future controller design. The simulation results show that a 100 W APU system in this research takes about 2 min (in theory) for start-up without considering the thermal limitation of the cell fracture.

  17. The minimum temperatures in the winter 2006/07 in the slovenian frost hollows and cold basins

    Directory of Open Access Journals (Sweden)

    Matej Ogrin

    2007-01-01

    Full Text Available The members of Slovenian Meteorological Forum, Department of Geography at Universityof Ljubljana and Slovenian Forestry Institute started to measure temperatures in Slovenianfrost hollows and cold basins in 2004. The measurements, which improved during theperiod 2004−2006, continued also in the winter 2006−2007, all together, in more than 30frost hollows and cold basins Alpine, Dinaridic and even Submediterranean areas. Althoughthe winter 2006/2007 was very mild, minimum temperatures in frost hollow Hribarice fellbelow − 35 ˚C.

  18. Operation of a Giant Magnetoresistive (GMR) Digital Isolator, Type IL510, Under Extreme Temperatures

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad; Panko, Scott

    2010-01-01

    A relatively new type of signal isolation based on Giant Magnetoresistive (GMR) technology was investigated for potential use in harsh temperature environments. Operational characteristics of the 2Mbps single channel, IL510-Series commercial-off-the-shelf (COTS) digital isolator chip was obtained under extreme temperature exposure and thermal cycling in the range of -190 C to +120 C. The isolator was evaluated in terms of its output signal delivery and stability, output rise (t(sub r)) and fall times (t(sub f)), and propagation delays at 50% level between input and output during low to high (t(sub PLH)) and high to low (t(sub PHL)) transitions. The device performed very well throughout the entire test temperature range as no significant changes occurred either in its function or in its output signal timing characteristics. The limited thermal cycling, which comprised of 12 cycles between -190 C and +120 C, also had no influence on its performance. In addition, the device packaging underwent no structural damage due to the extreme temperature exposure. These preliminary results indicate that this semiconductor chip has the potential for use in a temperature range that extends beyond its specified regime. Additional and more comprehensive testing, however, is required to establish its operation and reliability and to determine its suitability for long-term use in space exploration missions.

  19. Spectral photometry of extreme helium stars: Ultraviolet fluxes and effective temperature

    Science.gov (United States)

    Drilling, J. S.; Schoenberner, D.; Heber, U.; Lynas-Gray, A. E.

    1982-01-01

    Ultraviolet flux distributions are presented for the extremely helium rich stars BD +10 deg 2179, HD 124448, LSS 3378, BD -9 deg 4395, LSE 78, HD 160641, LSIV -1 deg 2, BD 1 deg 3438, HD 168476, MV Sgr, LS IV-14 deg 109 (CD -35 deg 11760), LSII +33 deg 5 and BD +1 deg 4381 (LSIV +2 deg 13) obtained with the International Ultraviolet Explorer (IUE). Broad band photometry and a newly computed grid of line blanketed model atmospheres were used to determine accurate angular diameters and total stellar fluxes. The resultant effective temperatures are in most cases in satisfactory agreement with those based on broad band photometry and/or high resolution spectroscopy in the visible. For two objects, LSII +33 deg 5 and LSE 78, disagreement was found between the IUE observations and broadband photometry: the colors predict temperatures around 20,000 K, whereas the UV spectra indicate much lower photospheric temperatures of 14,000 to 15,000 K. The new temperature scale for extreme helium stars extends to lower effective temperatures than that of Heber and Schoenberner (1981) and covers the range from 8,500 K to 32,000 K.

  20. Effect of temperatures and cold storage on performance of Tetrastichus brontispae (Hymenoptera: Eulophidae), a parasitoid of Brontispa longissima (Coleptera: Chrysomelidae).

    Science.gov (United States)

    Liu, Kui; Fu, Buli; Lin, Jiangrong; Fu, Yueguan; Peng, Zhengqiang; Jin, Qi'an

    2014-01-01

    Laboratory studies were conducted to determine the effect of temperature and cold storage on the performance of Tetrastichus brontispae (Ferriere) (Hymenoptera: Eulophidae), one of the major endoparasitoids against coconut hispine beetle, Brontispa longissima (Gestro) (Coleptera: Chrysomelidae). The results revealed that T. brontispae could successfully parasitize host pupae under all seven tested temperatures, but no adult emergence was observed at 32°C. It was also revealed that temperatures between 24 and 26°C appeared to be the optimum temperatures for parasitism, as these temperatures resulted in the most parasitized pupae and a significantly higher emergence rate and progeny production. These measurements significantly declined at 20, 30, and 32°C. This study confirmed developmental periods of parasitoid progeny decreased as the temperature increased, and sex ratio of this female-biased parasitoid was not affected by rearing temperatures. More importantly, this study indicated that cold storage of parasitized pupae could extend up to 30 d at 10°C, and a longer storage period had a significant adverse effect on mean adult emergence and parasitism performance. Ten days might be the optimum cold-storage period at 10°C, as parasitism performance, emergence rate, and progeny production at this storage period were similar to the control of 26°C. Furthermore, the developmental period, emergence rate, and sex ratio of progeny that emerged from cold-stored parasitized pupae were not influenced by storage periods, whereas parasitism performance of progeny decreased as storage period increased. This study suggests that about 24-26°C would be the optimal temperature for mass production and release of T. brontispae for biological control of B. longissima. These results also provide novel findings that a period of 10 d at 10°C may be more suitable and acceptable for ideal cold storage of parasitized pupae of T. brontispae.

  1. Twenty-five years of change in scleractinian coral communities of Daya Bay (northern South China Sea)and its response to the 2008 AD extreme cold climate event

    Institute of Scientific and Technical Information of China (English)

    CHEN TianRan; YU KeFu; SHI Qi; LI Shu; Gilbert J. Price; WANG Rong; ZHAO MeiXia; CHEN TeGu; ZHAO JianXin

    2009-01-01

    taking into account additional factors,we hypothesize that direct anthropogenic impacts, rather than climatic events, have both restricted the development, and drove the decline, of Daya Bay coral communities in the last 15 years. The Daya Bay has also been subjected to occasional extreme cold events during the past 50 years, with the most recent occurring in early 2008 (13 January-13 February). During the 2008 cold event, the lowest air temperature reaches only 6.6℃, and the mean sea surface temperature for February fall to<14℃, in-cluding six continuous days at 12.3℃. Significantly, the sea surface temperatures fall below the hypothesized critical lower temperature threshold (~13℃) that commonly leads to mass mortality in scleractinian coral communities. Surprisingly, our coral community surveys, conducted both before(August 2007) and after (late February 2008) the extreme 2008 cold event, demonstrate that the Daya Bay coral ecosystems are barely impacted upon during the cold period. Those observations suggest that the Daya Bay scleractinian coral communities have developed adaptations to low sea surface temperatures. Overall, our data support the hypothesis that high-latitude coral communities, such as Daya Bay, have the potential to act as areas of refugia for scieractinian corals in the advent of potential future global warming.

  2. Detection of Spatio-temporal variations of rainfall and temperature extremes over India

    Science.gov (United States)

    Hari, V.; Karmakar, S.; Ghosh, S.

    2012-12-01

    implemented. The results from this study exhibit the observable changes in the rainfall extreme events that occurred over India in past century. The country experienced large spatial heterogeneity of all the four rainfall variables, even in the meteorologically homogeneous regions. The correlation analyses show that the maximum grids are having positive correlation, however for the duration-frequency, a significant correlation is observed in few grids, with most of the grids showing no correlation. The spatial variation of RL shows spatial heterogeneity and trend analyses exhibit lack of uniformity throughout India. The change in RL shows significant positive change in mainly during past 50 years. The possible reason could be urbanization and change in climate variables. Hence for further investigation, this analysis will be associated with the temperature extremes data throughout India.

  3. 低温冷风-微量润滑技术在冷镦模具上的应用%The Application of Low-temperature Cold Air-Minimal Quantity Lubrication Technology to Cold Heading Die

    Institute of Scientific and Technical Information of China (English)

    朱红萍

    2011-01-01

    The main heat source of cold heading machine was analyzed.The low-temperature cold spray jet technology was applied to cold forging machine dies.A set of low-temperature cold spray jet system was designed.The heat sink structure of the die was optimized.%在分析冷镦机主要热源的基础上,将低温冷风喷雾射流技术运用到冷镦机模具上,设计了一套低温冷风喷雾射流系统,并对定模具的散热结构进行优化.

  4. Variability of temperature sensitivity of extreme precipitation from a regional-to-local impact scale perspective

    Science.gov (United States)

    Schroeer, K.; Kirchengast, G.

    2016-12-01

    Relating precipitation intensity to temperature is a popular approach to assess potential changes of extreme events in a warming climate. Potential increases in extreme rainfall induced hazards, such as flash flooding, serve as motivation. It has not been addressed whether the temperature-precipitation scaling approach is meaningful on a regional to local level, where the risk of climate and weather impact is dealt with. Substantial variability of temperature sensitivity of extreme precipitation has been found that results from differing methodological assumptions as well as from varying climatological settings of the study domains. Two aspects are consistently found: First, temperature sensitivities beyond the expected consistency with the Clausius-Clapeyron (CC) equation are a feature of short-duration, convective, sub-daily to sub-hourly high-percentile rainfall intensities at mid-latitudes. Second, exponential growth ceases or reverts at threshold temperatures that vary from region to region, as moisture supply becomes limited. Analyses of pooled data, or of single or dispersed stations over large areas make it difficult to estimate the consequences in terms of local climate risk. In this study we test the meaningfulness of the scaling approach from an impact scale perspective. Temperature sensitivities are assessed using quantile regression on hourly and sub-hourly precipitation data from 189 stations in the Austrian south-eastern Alpine region. The observed scaling rates vary substantially, but distinct regional and seasonal patterns emerge. High sensitivity exceeding CC-scaling is seen on the 10-minute scale more than on the hourly scale, in storms shorter than 2 hours duration, and in shoulder seasons, but it is not necessarily a significant feature of the extremes. To be impact relevant, change rates need to be linked to absolute rainfall amounts. We show that high scaling rates occur in lower temperature conditions and thus have smaller effect on absolute

  5. Effects of temperature and copper pollution on soil community--extreme temperature events can lead to community extinction.

    Science.gov (United States)

    Menezes-Oliveira, Vanessa B; Scott-Fordsmand, Janeck J; Soares, Amadeu M V M; Amorim, Monica J B

    2013-12-01

    Global warming affects ecosystems and species' diversity. The physiology of individual species is highly influenced by changes in temperature. The effects on species communities are less studied; they are virtually unknown when combining effects of pollution and temperature. To assess the effects of temperature and pollution in the soil community, a 2-factorial soil mesocosms multispecies experiment was performed. Three exposure periods (28 d, 61 d, and 84 d) and 4 temperatures (19 °C, 23 °C, 26 °C, and 29 °C) were tested, resembling the mean annual values for southern Europe countries and extreme events. The soil used was from a field site, clean, or spiked with Cu (100 mg Cu/kg). Results showed clear differences between 29 °C treatment and all other temperature treatments, with a decrease in overall abundance of organisms, further potentiated by the increase in exposure time. Folsomia candida was the most abundant species and Enchytraeus crypticus was the most sensitive to Cu toxicity. Differences in species optimum temperatures were adequately covered: 19 °C for Hypoaspis aculeifer or 26 °C for E. crypticus. The temperature effects were more pronounced the longer the exposure time. Feeding activity decreased with higher temperature and exposure time, following the decrease in invertebrate abundance, whereas for the same conditions the organic matter turnover increased. Hence, negative impacts on ecosystem services because of temperature increase can be expected by changes on soil function and as consequence of biodiversity loss. © 2013 SETAC.

  6. Temperature-related mortality in 17 large Chinese cities: how heat and cold affect mortality in China.

    Science.gov (United States)

    Ma, Wenjuan; Chen, Renjie; Kan, Haidong

    2014-10-01

    Few multicity studies have been conducted to investigate the acute health effects of cold and hot temperatures in China. We aimed to examine the relationship between temperature and daily mortality in 17 large Chinese cities. We first calculated city-specific effect of temperature using time-series regression models combined with distributed lag nonlinear models; then we pooled the city-specific estimates with the Bayesian hierarchical models. The cold effects lasted longer than the hot effects. For the cold effects, a 1 °C decrease from the 25th to 1st percentiles of temperature over lags 0-14 days was associated with increases of 1.69% [95% posterior intervals (PI): 1.01%, 2.36%], 2.49% (95% PI: 1.53%, 3.46%) and 1.60% (95% PI: 0.32%, 2.87%) in total, cardiovascular and respiratory mortality, respectively. For the hot effects, a 1 °C increase from the 75th to 99th percentiles of temperature was associated with corresponding increases of 2.83% (95% PI: 1.42%, 4.24%), 3.02% (95% PI: 1.33%, 4.71%) and 4.64% (95% PI: 1.96%, 7.31%). The latitudes, number of air conditioning per household and disposable income per capita were significant modifiers for cold effects; the proportion of the elderly was a significant modifier for hot effects. This largest epidemiological study of temperature to date in China suggested that both cold and hot temperatures were associated with increased mortality. Our findings may have important implications for the public health policies in China.

  7. Phosphoglucose isomerase genotype affects running speed and heat shock protein expression after exposure to extreme temperatures in a montane willow beetle.

    Science.gov (United States)

    Rank, Nathan E; Bruce, Douglas A; McMillan, David M; Barclay, Colleen; Dahlhoff, Elizabeth P

    2007-03-01

    Eastern Sierra Nevada populations of the willow beetle Chrysomela aeneicollis commonly experience stressfully high and low environmental temperatures that may influence survival and reproduction. Allele frequencies at the enzyme locus phosphoglucose isomerase (PGI) vary across a climatic latitudinal gradient in these populations, with PGI allele 1 being most common in cooler regions and PGI allele 4 in warmer ones. PGI genotypes differ in heat and cold tolerance and in expression of a 70 kDa heat shock protein. Here we examine genetic, behavioral and environmental factors affecting a performance character, running speed, for willow beetles, and assess effects of consecutive cold and heat exposure on running speed and expression of Hsp70 in the laboratory. In nature, running speed depends on air temperature and is higher for males than females. Mating beetles ran faster than single beetles, and differences among PGI genotypes in male running speed depended on the presence of females. In the laboratory, exposure to cold reduced subsequent running speed, but the amount of this reduction depended on PGI genotype and previous thermal history. Effects of exposure to heat also depended on life history stage and PGI genotype. Adults possessing allele 1 ran fastest after a single exposure to stressful temperature, whereas those possessing allele 4 ran faster after repeated exposure. Larvae possessing allele 4 ran fastest after a single stressful exposure, but running speed generally declined after a second exposure to stressful temperature. The ranking of PGI genotypes after the second exposure depended on whether a larva had been exposed to cold or heat. Effects of temperature on Hsp70 expression also varied among PGI genotypes and depended on type of exposure, especially for adults (single heat exposure, two cold exposures: PGI 1-1>1-4>4-4; other multiple extreme exposures: 4-4>1-4>1-1). There was no consistent association between alleles at other polymorphic enzyme loci

  8. Transcriptome profiling of low temperature-treated cassava apical shoots showed dynamic responses of tropical plant to cold stress

    Directory of Open Access Journals (Sweden)

    An Dong

    2012-02-01

    Full Text Available Abstract Background Cassava is an important tropical root crop adapted to a wide range of environmental stimuli such as drought and acid soils. Nevertheless, it is an extremely cold-sensitive tropical species. Thus far, there is limited information about gene regulation and signalling pathways related to the cold stress response in cassava. The development of microarray technology has accelerated the study of global transcription profiling under certain conditions. Results A 60-mer oligonucleotide microarray representing 20,840 genes was used to perform transcriptome profiling in apical shoots of cassava subjected to cold at 7°C for 0, 4 and 9 h. A total of 508 transcripts were identified as early cold-responsive genes in which 319 sequences had functional descriptions when aligned with Arabidopsis proteins. Gene ontology annotation analysis identified many cold-relevant categories, including 'Response to abiotic and biotic stimulus', 'Response to stress', 'Transcription factor activity', and 'Chloroplast'. Various stress-associated genes with a wide range of biological functions were found, such as signal transduction components (e.g., MAP kinase 4, transcription factors (TFs, e.g., RAP2.11, and reactive oxygen species (ROS scavenging enzymes (e.g., catalase 2, as well as photosynthesis-related genes (e.g., PsaL. Seventeen major TF families including many well-studied members (e.g., AP2-EREBP were also involved in the early response to cold stress. Meanwhile, KEGG pathway analysis uncovered many important pathways, such as 'Plant hormone signal transduction' and 'Starch and sucrose metabolism'. Furthermore, the expression changes of 32 genes under cold and other abiotic stress conditions were validated by real-time RT-PCR. Importantly, most of the tested stress-responsive genes were primarily expressed in mature leaves, stem cambia, and fibrous roots rather than apical buds and young leaves. As a response to cold stress in cassava, an increase

  9. Ignition and combustion of pyrotechnics at low pressures and at temperature extremes

    Directory of Open Access Journals (Sweden)

    Clive Woodley

    2017-06-01

    Full Text Available Rapid and effective ignition of pyrotechnic countermeasure decoy flares is vitally important to the safety of expensive military platforms such as aircraft. QinetiQ is conducting experimental and theoretical research into pyrotechnic countermeasure decoy flares. A key part of this work is the development and application of improved models to increase the understanding of the ignition processes occurring for these flares. These models have been implemented in a two-dimensional computational model and details are described in this paper. Previous work has conducted experiments and validated the computational model at ambient temperature and pressure. More recently the computational model has been validated at pressures down to that equivalent to 40,000 feet but at ambient temperature (∼290 K. This paper describes further experimental work in which the ignition delays of the priming material in inert countermeasure decoy flares were determined for pressures down to 40,000 feet and at temperature extremes of −40 °C and 100 °C. Also included in this paper is a comparison of the measured and predicted ignition delays at low pressures and temperature extremes. The agreement between the predicted and measured ignition delays is acceptable.

  10. Extreme summer temperatures in Iberia: health impacts and associated synoptic conditions

    Directory of Open Access Journals (Sweden)

    R. García-Herrera

    2005-02-01

    Full Text Available This paper examines the effect of extreme summer temperatures on daily mortality in two large cities of Iberia: Lisbon (Portugal and Madrid (Spain. Daily mortality and meteorological variables are analysed using the same methodology based on Box-Jenkins models. Results reveal that in both cases there is a triggering effect on mortality when maximum daily temperature exceeds a given threshold (34°C in Lisbon and 36°C in Madrid. The impact of most intense heat events is very similar for both cities, with significant mortality values occurring up to 3 days after the temperature threshold has been surpassed. This impact is measured as the percentual increase of mortality associated to a 1°C increase above the threshold temperature. In this respect, Lisbon shows a higher impact, 31%, as compared with Madrid at 21%. The difference can be attributed to demographic and socio-economic factors. Furthermore, the longer life span of Iberian women is critical to explain why, in both cities, females are more susceptible than males to heat effects, with an almost double mortality impact value.

    The analysis of Sea Level Pressure (SLP, 500hPa geopotential height and temperature fields reveals that, despite being relatively close to each other, Lisbon and Madrid have relatively different synoptic circulation anomalies associated with their respective extreme summer temperature days. The SLP field reveals higher anomalies for Lisbon, but extending over a smaller area. Extreme values in Madrid seem to require a more western location of the Azores High, embracing a greater area over Europe, even if it is not as deep as for Lisbon. The origin of the hot and dry air masses that usually lead to extreme heat days in both cities is located in Northern Africa. However, while Madrid maxima require wind blowing directly from the south, transporting heat from Southern Spain and Northern Africa, Lisbon maxima occur under more easterly

  11. Elucidating the impact of temperature variability and extremes on cereal croplands through remote sensing.

    Science.gov (United States)

    Duncan, John M A; Dash, Jadunandan; Atkinson, Peter M

    2015-04-01

    Remote sensing-derived wheat crop yield-climate models were developed to highlight the impact of temperature variation during thermo-sensitive periods (anthesis and grain-filling; TSP) of wheat crop development. Specific questions addressed are: can the impact of temperature variation occurring during the TSP on wheat crop yield be detected using remote sensing data and what is the impact? Do crop critical temperature thresholds during TSP exist in real world cropping landscapes? These questions are tested in one of the world's major wheat breadbaskets of Punjab and Haryana, north-west India. Warming average minimum temperatures during the TSP had a greater negative impact on wheat crop yield than warming maximum temperatures. Warming minimum and maximum temperatures during the TSP explain a greater amount of variation in wheat crop yield than average growing season temperature. In complex real world cereal croplands there was a variable yield response to critical temperature threshold exceedance, specifically a more pronounced negative impact on wheat yield with increased warming events above 35 °C. The negative impact of warming increases with a later start-of-season suggesting earlier sowing can reduce wheat crop exposure harmful temperatures. However, even earlier sown wheat experienced temperature-induced yield losses, which, when viewed in the context of projected warming up to 2100 indicates adaptive responses should focus on increasing wheat tolerance to heat. This study shows it is possible to capture the impacts of temperature variation during the TSP on wheat crop yield in real world cropping landscapes using remote sensing data; this has important implications for monitoring the impact of climate change, variation and heat extremes on wheat croplands. © 2014 John Wiley & Sons Ltd.

  12. Equation of state density models for hydrocarbons in ultradeep reservoirs at extreme temperature and pressure conditions

    Science.gov (United States)

    Wu, Yue; Bamgbade, Babatunde A.; Burgess, Ward A.; Tapriyal, Deepak; Baled, Hseen O.; Enick, Robert M.; McHugh, Mark A.

    2013-10-01

    The necessity of exploring ultradeep reservoirs requires the accurate prediction of hydrocarbon density data at extreme temperatures and pressures. In this study, three equations of state (EoS) models, Peng-Robinson (PR), high-temperature high-pressure volume-translated PR (HTHP VT-PR), and perturbed-chain statistical associating fluid theory (PC-SAFT) EoS are used to predict the density data for hydrocarbons in ultradeep reservoirs at temperatures to 523 K and pressures to 275 MPa. The calculated values are compared with experimental data. The results show that the HTHP VT-PR EoS and PC-SAFT EoS always perform better than the regular PR EoS for all the investigated hydrocarbons.

  13. Transcriptome Profiling of the Pineapple under Low Temperature to Facilitate Its Breeding for Cold Tolerance

    Science.gov (United States)

    Chen, Chengjie; Zhang, Yafeng; Xu, Zhiqiang; Luan, Aiping; Mao, Qi; Feng, Junting; Xie, Tao; Gong, Xue; Wang, Xiaoshuang; Chen, Hao; He, Yehua

    2016-01-01

    The pineapple (Ananas comosus) is cold sensitive. Most cultivars are injured during winter periods, especially in sub-tropical regions. There is a lack of molecular information on the pineapple’s response to cold stress. In this study, high-throughput transcriptome sequencing and gene expression analysis were performed on plantlets of a cold-tolerant genotype of the pineapple cultivar ‘Shenwan’ before and after cold treatment. A total of 1,186 candidate cold responsive genes were identified, and their credibility was confirmed by RT-qPCR. Gene set functional enrichment analysis indicated that genes related to cell wall properties, stomatal closure and ABA and ROS signal transduction play important roles in pineapple cold tolerance. In addition, a protein association network of CORs (cold responsive genes) was predicted, which could serve as an entry point to dissect the complex cold response network. Our study found a series of candidate genes and their association network, which will be helpful to cold stress response studies and pineapple breeding for cold tolerance. PMID:27656892

  14. Current Sharing Technology in Transmission Conductors of Cold Dielectric High Temperature Superconducting Cables Using Second-generation HTS Wires

    Institute of Scientific and Technical Information of China (English)

    ZHU Jiahui; BAO Xuzheng; QIU Ming

    2012-01-01

    The cold dielectric high temperature superconducting (CD HTS) cable has multilayer conductors. The non-uniform AC current distribution in these multilayer conductors will increase the AC loss and decrease the current transmission efficiency. So it is important to understand the current sharing among layers in order to fully exploit the performance of the HTS cable.

  15. The Role of Cold-Shock Proteins in Low-Temperature Adaptation of Food-Related Bacteria

    NARCIS (Netherlands)

    Wouters, Jeroen A.; Rombouts, Frank M.; Kuipers, Oscar P.; Vos, Willem M. de; Abee, T.

    2000-01-01

    There is a considerable interest in the cold adaptation of food-related bacteria, including starter cultures for industrial food fermentations, food spoilage bacteria and food-borne pathogens. Mechanisms that permit low-temperature growth involve cellular modifications for maintaining membrane fluid

  16. Composite Materials under Extreme Radiation and Temperature Environments of the Next Generation Nuclear Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Simos, N.

    2011-05-01

    In the nuclear energy renaissance, driven by fission reactor concepts utilizing very high temperatures and fast neutron spectra, materials with enhanced performance that exceeds are expected to play a central role. With the operating temperatures of the Generation III reactors bringing the classical reactor materials close to their performance limits there is an urgent need to develop and qualify new alloys and composites. Efforts have been focused on the intricate relations and the high demands placed on materials at the anticipated extreme states within the next generation fusion and fission reactors which combine high radiation fluxes, elevated temperatures and aggressive environments. While nuclear reactors have been in operation for several decades, the structural materials associated with the next generation options need to endure much higher temperatures (1200 C), higher neutron doses (tens of displacements per atom, dpa), and extremely corrosive environments, which are beyond the experience on materials accumulated to-date. The most important consideration is the performance and reliability of structural materials for both in-core and out-of-core functions. While there exists a great body of nuclear materials research and operating experience/performance from fission reactors where epithermal and thermal neutrons interact with materials and alter their physio-mechanical properties, a process that is well understood by now, there are no operating or even experimental facilities that will facilitate the extreme conditions of flux and temperature anticipated and thus provide insights into the behaviour of these well understood materials. Materials, however, still need to be developed and their interaction and damage potential or lifetime to be quantified for the next generation nuclear energy. Based on material development advances, composites, and in particular ceramic composites, seem to inherently possess properties suitable for key functions within the

  17. Part 2. Association of daily mortality with ambient air pollution, and effect modification by extremely high temperature in Wuhan, China.

    Science.gov (United States)

    Qian, Zhengmin; He, Qingci; Lin, Hung-Mo; Kong, Lingli; Zhou, Dunjin; Liang, Shengwen; Zhu, Zhichao; Liao, Duanping; Liu, Wenshan; Bentley, Christy M; Dan, Jijun; Wang, Beiwei; Yang, Niannian; Xu, Shuangqing; Gong, Jie; Wei, Hongming; Sun, Huilin; Qin, Zudian

    2010-11-01

    the logarithm of daily counts of mortality due to all natural causes and cause-specific mortality on the daily mean concentrations of the four pollutants while controlling for weather, temporal factors, and other important covariates with generalized additive models (GAMs). We derived pollutant effect estimations for 0-day, 1-day, 2-day, 3-day, and 4-day lagged exposure levels, and the averages of 0-day and 1-day lags (lag 0-1 day) and of 0-day, 1-day, 2-day, and 3-day lags (lag 0-3 days) before the event of death. In addition, we used individual-level data (e.g., age and sex) to classify subgroups in stratified analyses. Furthermore, we explored the nonlinear shapes ("thresholds") of the exposure-response relations. To achieve the second aim, we tested the hypothesis that extremely high temperature modifies the associations between air pollution and daily mortality. We developed three corresponding weather indicators: "extremely hot," "extremely cold," and "normal temperatures." The estimates were obtained from the models for the main effects and for the pollutant-temperature interaction for each pollutant and each cause of mortality. To achieve the third aim, we conducted an additional analysis. We examined the concordance rates and kappa statistics between the ICD-9-coded mortality data and the ICD-10-coded mortality data for the year 2002. We also compared the magnitudes of the estimated effects resulting from the use of the two types of ICD-coded mortality data. In general, the largest pollutant effects were observed at lag 0-1 day. Therefore, for this report, we focused on the results obtained from the lag 0-1 models. We observed consistent associations between PM10 and mortality: every 10-microg/m3 increase in PM10 daily concentration at lag 0-1 day produced a statistically significant association with an increase in mortality due to all natural causes (0.43%; 95% confidence interval [CI], 0.24 to 0.62), CVD (0.57%; 95% CI, 0.31 to 0.84), stroke (0.57%; 95% CI

  18. Implications of dynamics underlying temperature and precipitation distributions for changes in extremes

    Science.gov (United States)

    Neelin, J. D.; Loikith, P. C.; Stechmann, S. N.; Sahany, S.; Bernstein, D. N.; Quinn, K. M.; Meyerson, J.; Hales, K.; Langenbrunner, B.

    2015-12-01

    Characterizing present-day probability distributions of temperature and precipitation measures are an important part of the pathway to improving quantitative assessment of changes in their extremes. In some cases, relatively simple prototypes for the dynamics underlying these distributions can assist in this characterization, pointing to key physical factors and measures to evaluate even in more complex distributions. In the case of daily temperature distributions, quantifying the widespread occurrence of non-Gaussian tails is motivated in part by tracer-advection across a maintained gradient prototypes. Substantial implications of the shape of these tails for regional changes in probabilities of temperature extremes with large-scale warming motivate measures of non-Gaussianity specific to this problem for assessing climate model present-day simulations. In the case of distributions of precipitation accumulations, simple prototypes yield insights into the form of the present-day distribution and predictions for the form of the global warming changes that can be evaluated in models and observations. Probability drops relatively slowly over a substantial range of accumulation size, followed by a key cutoff scale that limits large event probabilities in current climate but changes under global warming. Precipitation integrated over spatial clusters exhibits similar distribution features.

  19. Extremely Low Frequency Electromagnetic Field from Convective Air Warming System on Temperature Selection and Distance.

    Directory of Open Access Journals (Sweden)

    Kwang Rae Cho

    2014-12-01

    Full Text Available Hypothermia generates potentially severe complications in operating or recovery room. Forced air warmer is effective to maintain body temperature. Extremely low frequency electromagnetic field (ELF-EMF is harmful to human body and mainly produced by electronic equipment including convective air warming system. We investigated ELF-EMF from convective air warming device on various temperature selection and distance for guideline to protect medical personnel and patients.The intensity of ELF-EMF was measured as two-second interval for five minutes on various distance (0.1, 0.2, 0.3, 0.5 and 1meter and temperature selection (high, medium, low and ambient. All of electrical devices were off including lamp, computer and air conditioner. Groups were compared using one-way ANOVA. P<0.05 was considered significant.Mean values of ELF-EMF on the distance of 30 cm were 18.63, 18.44, 18.23 and 17.92 milligauss (mG respectively (high, medium, low and ambient temperature set. ELF-EMF of high temperature set was higher than data of medium, low and ambient set in all the distances.ELF-EMF from convective air warming system is higher in condition of more close location and higher temperature. ELF-EMF within thirty centimeters exceeds 2mG recommended by Swedish TCO guideline.

  20. The Effect of Local Heat and Cold Therapy on the Intraarticular and Skin Surface Temperature of the Knee

    OpenAIRE

    1992-01-01

    Objective. To evaluate the effects of local application of ice chips, ligno-paraffin, short-wave diathermy, and nitrogen-cold air on skin and intraarticular temperature. Methods. Forty-two healthy subjects were divided into 4 treatment groups. A temperature probe was inserted into the knee joint cavity and another placed on the overlying skin, and changes in temperature over 3 hours, by treatment group, were recorded. Results. The mean skin surface temperature dropped from 27.9°C to 11.5°C af...

  1. Composite self-similar solutions for relativistic shocks: The transition to cold fluid temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Margaret [School of Natural Sciences, Institute for Advanced Study, Princeton, New Jersey 08540 (United States); Sari, Re' em [California Institute of Technology, MS 130-33, Pasadena, California 91125 (United States) and Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

    2009-11-15

    The flow resulting from a strong ultrarelativistic shock moving through a stellar envelope with a polytropelike density profile has been studied analytically and numerically at early times while the fluid temperature is relativistic--that is, just before and after the shock breaks out of the star. Such a flow should expand and accelerate as its internal energy is converted to bulk kinetic energy; at late enough times, the assumption of relativistic temperatures becomes invalid. Here we present a new self-similar solution for the postbreakout flow when the accelerating fluid has bulk kinetic Lorentz factors much larger than unity but is cooling through p/n of order unity to subrelativistic temperatures. This solution gives a relation between a fluid element's terminal Lorentz factor and that element's Lorentz factor just after it is shocked. Our numerical integrations agree well with the solution. While our solution assumes a planar flow, we show that corrections due to spherical geometry are important only for extremely fast ejecta originating in a region very close to the stellar surface. This region grows if the shock becomes relativistic deeper in the star.

  2. Cold snaps still a threat despite global warming

    Science.gov (United States)

    Schultz, Colin

    2011-07-01

    Long stretches of extreme cold weather can cause serious damage to agriculture as well as to transportation, water, and energy infrastructure. Cold snaps have the potential to kill people, with deaths attributed to cold weather often outpacing those caused by extreme heat. With climate projections anticipating at least 2deg;C increases in global average temperature by the end of the century, some regional planners may be taking solace in the idea that the threat of cold weather extremes could fade as the world warms. Research by Kodra et al., however, suggests that on a global scale the intensity and duration of extreme cold weather events will persist and in some regions will possibly even increase by the end of the 21st century. (Geophysical Research Letters, doi:10.1029/ 2011GL047103, 2011)

  3. Mesoscale convection system and occurrence of extreme low tropopause temperatures. Observations over Asian summer monsoon region

    Energy Technology Data Exchange (ETDEWEB)

    Jain, A.R.; Mandal, T.K.; Gautam, R. [National Physical Laboratory, New Delhi (India). Radio and Atmospheric Div.; Panwar, V. [National Physical Laboratory, New Delhi (India). Radio and Atmospheric Div.; Delhi Univ. (India). Dept. of Physics and Astrophysics; Rao, V.R. [India Meteorology Dept., New Delhi (India). Satellite Meteorology Div.; Goel, A. [Delhi Univ. (India). Dept. of Physics and Astrophysics; Das, S.S. [Vikram Sarabhai Space Center, Trivandrum (India). Space Physics Lab.; Dhaka, S.K. [Delhi Univ., New Delhi (India). Dept. of Physics and Electronics

    2010-07-01

    The present study examines the process of how tropospheric air enters the stratosphere, particularly in association with tropical mesoscale convective systems (TMCS) which are considered to be one of the causative mechanisms for the observation of extremely low tropopause temperature over the tropics. The association between the phenomena of convection and the observation of extreme low tropopause temperature events is, therefore, examined over the Asian monsoon region using data from multiple platforms. Satellite observations show that the area of low outgoing long wave radiation (OLR), which is a proxy for the enhanced convection, is embedded with high altitude clouds top temperatures ({<=}193 K). A detailed analysis of OLR and 100 hPa temperature shows that both are modulated by westward propagating Rossby waves with a period of {proportional_to}15 days, indicating a close linkage between them. The process by which the tropospheric air enters the stratosphere may, in turn, be determined by how the areas of convection and low tropopause temperature (LTT) i.e. T {<=}191K are spatially located. In this context, the relative spatial distribution of low OLR and LTT areas is examined. Though, the locations of low OLR and LTT are noticed in the same broad area, the two do not always overlap, except for partial overlap in some cases. When there are multiple low OLR areas, the LTT area generally appears in between the low OLR areas. Implications of these observations are also discussed. The present analysis also shows that the horizontal mean winds have a role in the spatial distribution of low OLR and LTT. (orig.)

  4. Relationship between athlete’s men cortisol with leukocytosis and Neutrophils numbers after exercise in cold, warm and normal temperatures conditions

    Directory of Open Access Journals (Sweden)

    Abbas Ali Gaeini

    2012-02-01

    Full Text Available Background & Objective: Exercise and extreme environments, causes hormonal and immune systems changes. Therefore, the purpose of this study was evaluating the relationship between cortisol and leukocytosis and Neutrophil numbers after exercise in cold, warm and natural temperatures. Materials & Methods: Ten young male athletes ran on a treadmill for an hour at the intensity of %60VO2max in three temperature conditions of normal (22±1˚c, 50±5RH, cold (3±1˚c, 50±2RH and warm (35±1˚c, 50±5RH. Blood samples were collected before and immediately after exercise. The total numbers of leukocytes and neutrophils were computed using Sysmex Kohden Nihon and serum cortisol concentrations determined by using ELISA. For comparing of data before and after exercise used from Paired T-test and for examine the relationship between variables used from Pearson Correlation Coefficient test. Results: The total leukocytes and the cortisol levels increased significantly after the exercise, in all the conditions (p<0.0001. Also, the number of neutrophils increased significantly after exercise in cold (p=0.001 and normal (p=0.001 environments. In addition, a significant relation was observed between cortisol levels and leukocytosis (R=0.783, P=0.007 and R=0.813, P=0.004 and between cortisol and Neutrophils after exercising in the natural and warm environment (R=0.806, P=0.005 and R=0.852, P=0.002. But, there was no significant relationship between these values after exercise in cold (R=0.63, P=0.051 and R=0.554, P=0.096. Conclusion: Exercise in all the three conditions causes the release of cortisol through stimulating the hypothalamic-pituitary- adrenal (HPA and effect of cortisol receptor on immune cells could cause increase Neutrophils and leukocytosis. It seems that elevation of cortisol concentration during exercise in warm and natural environments is responsible for increase Neutrophils and leukocytosis. Moreover, during exercise in cold environments

  5. Biosynthesis and uptake of glycine betaine as cold-stress response to low temperature in fish pathogen Vibrio anguillarum.

    Science.gov (United States)

    Ma, Yue; Wang, Qiyao; Gao, Xiating; Zhang, Yuanxing

    2017-01-01

    Fish pathogen Vibrio anguillarum, a mesophile bacterium, is usually found in estuarine and marine coastal ecosystems worldwide that pose a constant stress to local organism by its fluctuation in salinity as well as notable temperature change. Though V. anguillarum is able to proliferate while maintain its pathogenicity under low temperature (5-18°C), so far, coldadaption molecular mechanism of the bacteria is unknown. In this study, V. anguillarum was found possessing a putative glycine betaine synthesis system, which is encoded by betABI and synthesizes glycine betaine from its precursor choline. Furthermore, significant up-regulation of the bet gene at the transcriptional level was noted in log phase in response to cold-stress. Moreover, the accumulation of betaine glycine was only found appearing at low growth temperatures, suggesting that response regulation of both synthesis system and transporter system are cold-dependent. Furthermore, in-frame deletion mutation in the two putative ABC transporters and three putative BCCT family transporters associated with glycine betaine uptake could not block cellular accumulation of betaine glycine in V. anguillarum under coldstress, suggesting the redundant feature in V. anguillarum betaine transporter system. These findings confirmed that glycine betaine serves as an effective cold stress protectant and highlighted an underappreciated facet of the acclimatization of V. anguillarum to cold environments.

  6. Quantitative methods for stochastic high frequency spatio-temporal and non-linear analysis: Assessing health effects of exposure to extreme ambient temperature

    Science.gov (United States)

    Liss, Alexander

    Extreme weather events, such as heat waves and cold spells, cause substantial excess mortality and morbidity in the vulnerable elderly population, and cost billions of dollars. The accurate and reliable assessment of adverse effects of extreme weather events on human health is crucial for environmental scientists, economists, and public health officials to ensure proper protection of vulnerable populations and efficient allocation of scarce resources. However, the methodology for the analysis of large national databases is yet to be developed. The overarching objective of this dissertation is to examine the effect of extreme weather on the elderly population of the Conterminous US (ConUS) with respect to seasonality in temperature in different climatic regions by utilizing heterogeneous high frequency and spatio-temporal resolution data. To achieve these goals the author: 1) incorporated dissimilar stochastic high frequency big data streams and distinct data types into the integrated data base for use in analytical and decision support frameworks; 2) created an automated climate regionalization system based on remote sensing and machine learning to define climate regions for the Conterminous US; 3) systematically surveyed the current state of the art and identified existing gaps in the scientific knowledge; 4) assessed the dose-response relationship of exposure to temperature extremes on human health in relatively homogeneous climate regions using different statistical models, such as parametric and non-parametric, contemporaneous and asynchronous, applied to the same data; 5) assessed seasonal peak timing and synchronization delay of the exposure and the disease within the framework of contemporaneous high frequency harmonic time series analysis and modification of the effect by the regional climate; 6) modeled using hyperbolic functional form non-linear properties of the effect of exposure to extreme temperature on human health. The proposed climate

  7. SiC JFET Transistor Circuit Model for Extreme Temperature Range

    Science.gov (United States)

    Neudeck, Philip G.

    2008-01-01

    A technique for simulating extreme-temperature operation of integrated circuits that incorporate silicon carbide (SiC) junction field-effect transistors (JFETs) has been developed. The technique involves modification of NGSPICE, which is an open-source version of the popular Simulation Program with Integrated Circuit Emphasis (SPICE) general-purpose analog-integrated-circuit-simulating software. NGSPICE in its unmodified form is used for simulating and designing circuits made from silicon-based transistors that operate at or near room temperature. Two rapid modifications of NGSPICE source code enable SiC JFETs to be simulated to 500 C using the well-known Level 1 model for silicon metal oxide semiconductor field-effect transistors (MOSFETs). First, the default value of the MOSFET surface potential must be changed. In the unmodified source code, this parameter has a value of 0.6, which corresponds to slightly more than half the bandgap of silicon. In NGSPICE modified to simulate SiC JFETs, this parameter is changed to a value of 1.6, corresponding to slightly more than half the bandgap of SiC. The second modification consists of changing the temperature dependence of MOSFET transconductance and saturation parameters. The unmodified NGSPICE source code implements a T(sup -1.5) temperature dependence for these parameters. In order to mimic the temperature behavior of experimental SiC JFETs, a T(sup -1.3) temperature dependence must be implemented in the NGSPICE source code. Following these two simple modifications, the Level 1 MOSFET model of the NGSPICE circuit simulation program reasonably approximates the measured high-temperature behavior of experimental SiC JFETs properly operated with zero or reverse bias applied to the gate terminal. Modification of additional silicon parameters in the NGSPICE source code was not necessary to model experimental SiC JFET current-voltage performance across the entire temperature range from 25 to 500 C.

  8. Effect of extreme temperatures on battery charging and performance of electric vehicles

    Science.gov (United States)

    Lindgren, Juuso; Lund, Peter D.

    2016-10-01

    Extreme temperatures pose several limitations to electric vehicle (EV) performance and charging. To investigate these effects, we combine a hybrid artificial neural network-empirical Li-ion battery model with a lumped capacitance EV thermal model to study how temperature will affect the performance of an EV fleet. We find that at -10 °C, the self-weighted mean battery charging power (SWMCP) decreases by 15% compared to standard 20 °C temperature. Active battery thermal management (BTM) during parking can improve SWMCP for individual vehicles, especially if vehicles are charged both at home and at workplace; the median SWMCP is increased by over 30%. Efficiency (km/kWh) of the vehicle fleet is maximized when ambient temperature is close to 20 °C. At low (-10 °C) and high (+40 °C) ambient temperatures, cabin preconditioning and BTM during parking can improve the median efficiency by 8% and 9%, respectively. At -10 °C, preconditioning and BTM during parking can also improve the fleet SOC by 3-6%-units, but this also introduces a "base" load of around 140 W per vehicle. Finally, we observe that the utility of the fleet can be increased by 5%-units by adding 3.6 kW chargers to workplaces, but further improved charging infrastructure would bring little additional benefit.

  9. Increase of record-breaking temperature and precipitation extremes in a warming world

    Science.gov (United States)

    Coumou, D.; Lehmann, J.; Robinson, A.; Rahmstorf, S.

    2011-12-01

    The last decade has seen many record-breaking weather events, including severe heat waves, as well as rainfall and drought extremes. At the same time, this decade was globally the warmest since accurate measurements started in the 19th century. This raises the question, often asked by public and media directly after the occurrence of a specific extreme, whether these extremes are related to global warming. Here we analyze record-breaking events in the last decade using global gridded datasets of monthly-mean surface temperature and precipitation. We compare the number of observed records with those expected in a stationary climate, for which the simple 1/n relationship holds, with n the number of previous data points (e.g. years). In addition, we develop a first-order theoretical model to quantify the respective contributions of climate change and natural variability to the occurrence of records. World wide the number of monthly heat records is now, on average 5 times larger than expected in a stationary climate. This indicates that record-breaking heat waves lasting for several weeks now have, on average, an 80% chance of being due to climatic warming. Some tropical regions including East-Africa, India and Amazonia have seen an even larger increase in the number of record breaking events, pushing the probability that a record event is due to climatic warming to more than 90%. The high number of observed records is well explained by a model assuming a linear warming over the last 40 years. Precipitation extremes are more complex than heat extremes as different physical processes associated with global warming are likely to affect them. Warmer air can hold more moisture and thus, in principle, enhances extremes in both rainfall maxima and minima. Also, changes in wind patterns will affect precipitation and it is expected that dry areas will become drier and wet areas wetter. We show that, globally averaged the number of observed records, both for minima and maxima

  10. Estimating the Effect of Climate Change on Crop Yields and Farmland Values: The Importance of Extreme Temperatures

    Science.gov (United States)

    This is a presentation titled Estimating the Effect of Climate Change on Crop Yields and Farmland Values: The Importance of Extreme Temperatures that was given for the National Center for Environmental Economics

  11. Multiple water isotope proxy reconstruction of extremely low last glacial temperatures in Eastern Beringia (Western Arctic)

    Science.gov (United States)

    Porter, Trevor J.; Froese, Duane G.; Feakins, Sarah J.; Bindeman, Ilya N.; Mahony, Matthew E.; Pautler, Brent G.; Reichart, Gert-Jan; Sanborn, Paul T.; Simpson, Myrna J.; Weijers, Johan W. H.

    2016-04-01

    Precipitation isotopes are commonly used for paleothermometry in high latitude regions. Here we present multiple water isotope proxies from the same sedimentary context - perennially frozen loess deposits in the Klondike Goldfields in central Yukon, Canada, representing parts of Marine Isotope Stages (MIS) 4, 3 and 2 - allowing us to uniquely corroborate fractionations and temperature conversions during these Late Pleistocene cold stages. We include new and existing proxy data from: relict wedge ice, a direct archive for snowmelt; relict pore ice, an archive for bulk soil water integrating year-round precipitation; and hydrated volcanic glass shards and fossil plant waxes, which are also thought to integrate year-round precipitation but are subject to large fractionations. In some cases, our temperature estimates based on existing proxy data are much cooler than previously estimated due to our use of source water corrections for the glacial ocean, new transfer functions calibrated specifically for northern North America (δDprecip = 3.1‰·°C-1 × T - 155‰; and δ18Oprecip = 0.41‰·°C-1 × T - 20.2‰), and novel insights on the apparent net fractionation correction for Eastern Beringian steppe-tundra plant waxes (εwax/precip = -59 ± 10‰). The snowmelt origin of wedge ice ensures a relatively constrained winter-spring seasonality of contributing precipitation, as supported by the consistency between water isotope measurements from Late Holocene wedge ice and modern winter-spring precipitation. Wedge ice dating to the transitional MIS 3/2 is isotopically depleted relative to modern spring-winter precipitation by an amount that indicates a temperature depression of ∼14 ± 5 °C below modern. The soil water origin of pore ice, and other proxies integrating year-round precipitation from soil water, allows for a more variable precipitation seasonality. The isotopic composition of modern pore ice is consistent with mean annual precipitation. However, the

  12. A new mean-extreme vector for the trends of temperature and precipitation over China during 1960-2013

    Science.gov (United States)

    Lyra, G. B.; Oliveira-Júnior, J. F.; Gois, G.; Cunha-Zeri, G.; Zeri, M.

    2016-06-01

    A mean-extreme (M-E) vector is defined to combine the changes of climate means and extremes. The direction of the vertical axis represents changes in means, whereas the direction of the horizontal axis represents changes in extremes. Therefore, the M-E vector can clearly reflect both the amplitude and direction of changes in climate means and extremes. Nine types of M-E vectors are defined. They are named as MuEu, MuEd, MuEz, MdEu, MdEd, MdEz, MzEu, MzEd, and MzEz. Here M and E stand for climate means and extremes, respectively, whereas u, d, and z indicate an upward, downward trend and no trend, respectively. Both temperature mean and extremely high temperature days are consistently increased (MuEu) in nearly whole China throughout four seasons. However, the MuEd-type vector dominates in some regions. The MuEd-type vector appears over the Huang Huai river basin in spring, summer and winter. For the M-E vector of temperature mean and extremely low temperature days, the MuEd-type spreads the entire China for all seasons. The M-E vector for precipitation mean and the extreme precipitation days possesses identical trends (MuEu or MdEd) despite of seasons. The MuEu-type dominates in northeastern China and west of 105°E in spring, northwestern and central/southern China in summer, west of 100°E and northeastern China in autumn, and nearly whole China in winter. Precipitation mean and extreme precipitation days are all decreased (MdEd) in the rest of China for all reasons. The trends relationship in means and extremes over China presented herein could provide a scientific foundation to predict change of extremes using change of mean as the predictor.

  13. Reducing the loss of vaccines from accidental freezing in the cold chain: the experience of continuous temperature monitoring in Tunisia.

    Science.gov (United States)

    Lloyd, John; Lydon, Patrick; Ouhichi, Ramzi; Zaffran, Michel

    2015-02-11

    Accidental freezing of vaccines is a growing threat and a real risk for national immunization programs when the potency of many vaccines can be compromised if these are exposed to sub-zero temperatures in the cold chain. In Tunisia, this issue is compounded by using sub-standard domestic cold chain equipment instead of equipping the program with medical refrigerators designed specifically for storing vaccines and temperature sensitive pharmaceuticals. Against this backdrop, this paper presents the findings of a demonstration project conducted in Tunisia in 2012 that tested the impact of introducing several freeze prevention solutions to mitigate the risk of accidental freezing of vaccines. The main finding is that, despite the continued use of underperforming domestic refrigerators, continuous temperature monitoring using new technologies combined with other technological interventions significantly reduced the prevalence of accidental exposure to freezing temperatures. These improvements were noticed for cold chain storage at regional, district and health center levels, and during the transport legs that were part of the demonstration conducted in the regions of Kasserine in the South-Eastern part of Tunisia. Subsequent to introducing these freeze prevention solutions, the incidence of freeze alarms was reduced and the percent of time the temperatures dropped below the 2 °C recommended threshold. The incidence of freeze alarms at health center level was reduced by 40%. Lastly, the solutions implemented reduced risk of freezing during transport from 13.8% to 1.7%. Although the solution implemented is not optimal in the longer term because domestic refrigerators are used extensively in district stores and health centers, the risk of accidental freezing is significantly reduced by introducing the practice of continuous temperature monitoring as a standard. The management of the cold chain equipment was strengthened as a result which helps protect the potency of

  14. A Cold-Inducible DEAD-Box RNA Helicase from Arabidopsis thaliana Regulates Plant Growth and Development under Low Temperature.

    Directory of Open Access Journals (Sweden)

    Yuelin Liu

    Full Text Available DEAD-box RNA helicases comprise a large family and are involved in a range of RNA processing events. Here, we identified one of the Arabidopsis thaliana DEAD-box RNA helicases, AtRH7, as an interactor of Arabidopsis COLD SHOCK DOMAIN PROTEIN 3 (AtCSP3, which is an RNA chaperone involved in cold adaptation. Promoter:GUS transgenic plants revealed that AtRH7 is expressed ubiquitously and that its levels of the expression are higher in rapidly growing tissues. Knockout mutant lines displayed several morphological alterations such as disturbed vein pattern, pointed first true leaves, and short roots, which resemble ribosome-related mutants of Arabidopsis. In addition, aberrant floral development was also observed in rh7 mutants. When the mutants were germinated at low temperature (12°C, both radicle and first leaf emergence were severely delayed; after exposure of seedlings to a long period of cold, the mutants developed aberrant, fewer, and smaller leaves. RNA blots and circular RT-PCR revealed that 35S and 18S rRNA precursors accumulated to higher levels in the mutants than in WT under both normal and cold conditions, suggesting the mutants are partially impaired in pre-rRNA processing. Taken together, the results suggest that AtRH7 affects rRNA biogenesis and plays an important role in plant growth under cold.

  15. A Cold-Inducible DEAD-Box RNA Helicase from Arabidopsis thaliana Regulates Plant Growth and Development under Low Temperature.

    Science.gov (United States)

    Liu, Yuelin; Tabata, Daisuke; Imai, Ryozo

    2016-01-01

    DEAD-box RNA helicases comprise a large family and are involved in a range of RNA processing events. Here, we identified one of the Arabidopsis thaliana DEAD-box RNA helicases, AtRH7, as an interactor of Arabidopsis COLD SHOCK DOMAIN PROTEIN 3 (AtCSP3), which is an RNA chaperone involved in cold adaptation. Promoter:GUS transgenic plants revealed that AtRH7 is expressed ubiquitously and that its levels of the expression are higher in rapidly growing tissues. Knockout mutant lines displayed several morphological alterations such as disturbed vein pattern, pointed first true leaves, and short roots, which resemble ribosome-related mutants of Arabidopsis. In addition, aberrant floral development was also observed in rh7 mutants. When the mutants were germinated at low temperature (12°C), both radicle and first leaf emergence were severely delayed; after exposure of seedlings to a long period of cold, the mutants developed aberrant, fewer, and smaller leaves. RNA blots and circular RT-PCR revealed that 35S and 18S rRNA precursors accumulated to higher levels in the mutants than in WT under both normal and cold conditions, suggesting the mutants are partially impaired in pre-rRNA processing. Taken together, the results suggest that AtRH7 affects rRNA biogenesis and plays an important role in plant growth under cold.

  16. An Experimental Study on the Drag Property of High-Temperature Particles Falling into Cold Liquid Pool

    Institute of Scientific and Technical Information of China (English)

    李小燕; 匡波; 杨燕华; 徐济鋆

    2003-01-01

    This experiment is to study the special resistant induced by the high-speed evaporation surrounding themoving high-temperature particles. An observable equipment was designed, in which the first 11 experiments wereperformed by pouring one or several Zirconia spheres with various high-temperature and a diameter of 3~ 10 mminto a water pool. The particles falling-down speeds were recorded by high-speed photographic instrumentation,and pressures and water temperatures were measured. A comparison between the experiments with cold and hotspheres respectively, employing three different sphere types each, was presented. The experimental data, com-pared with the theory of the evaporation drag model, are nearly identical.

  17. Influence of state of Nb on recrystallization temperature during annealing in cold-rolled low-carbon steels

    Energy Technology Data Exchange (ETDEWEB)

    Ogawa, Toshio, E-mail: ogawa.m8b.toshio@jp.nssmc.com [Nagoya Works, Nippon Steel and Sumitomo Metal Corporation, 5-3 Tokai-machi, Tokai-shi, Aichi 476-8686 (Japan); Sugiura, Natsuko [Steel Research Laboratories, Nippon Steel and Sumitomo Metal Corporation, 20-1 Shintomi, Futtsu, Chiba 293-8511 (Japan); Maruyama, Naoki; Yoshinaga, Naoki [Kimitsu R and D Laboratories, Nippon Steel and Sumitomo Metal Corporation, 1 Kimitsu, Kimitsu, Chiba 299-1141 (Japan)

    2013-03-01

    The influence of state of Nb on recrystallization temperature during annealing in cold-rolled low-carbon steels was investigated. Two kinds of specimens showing a remarkable difference in recrystallization temperature were prepared. Differences in the features of Nb-containing precipitates larger than 3 nm were rarely observed, whereas differences in precipitates smaller than 3 nm were confirmed by atom-probe field-ion microscopy in each hot-rolled sheet. The difference in the recrystallization temperatures of both specimens probably originates in the state of Nb at the atomic scale before annealing.

  18. The oxidation behavior of classical thermal barrier coatings exposed to extreme temperature

    Directory of Open Access Journals (Sweden)

    Alina DRAGOMIRESCU

    2017-03-01

    Full Text Available Thermal barrier coatings (TBC are designed to protect metal surfaces from extreme temperatures and improve their resistance to oxidation during service. Currently, the most commonly used systems are those that have the TBC structure bond coat (BC / top coat (TC layers. The top coat layer is a ceramic layer. Oxidation tests are designed to identify the dynamics of the thermally oxide layer (TGO growth at the interface of bond coat / top coat layers, delamination mechanism and the TBC structural changes induced by thermal conditions. This paper is a short study on the evolution of aluminum oxide protective layer along with prolonged exposure to the testing temperature. There have been tested rectangular specimens of metal super alloy with four surfaces coated with a duplex thermal barrier coating system. The specimens were microscopically and EDAX analyzed before and after the tests. In order to determine the oxide type, the samples were analyzed using X-ray diffraction. The results of the investigation are encouraging for future studies. The results show a direct relationship between the development of the oxide layer and long exposure to the test temperature. Future research will focus on changing the testing temperature to compare the results.

  19. Extreme Brightness Temperatures and Refractive Substructure in 3C273 with RadioAstron

    CERN Document Server

    Johnson, Michael D; Gwinn, Carl R; Gurvits, Leonid I; Narayan, Ramesh; Macquart, Jean-Pierre; Jauncey, David L; Voitsik, Peter A; Anderson, James M; Sokolovsky, Kirill V; Lisakov, Mikhail M

    2016-01-01

    Earth-space interferometry with RadioAstron provides the highest direct angular resolution ever achieved in astronomy at any wavelength. RadioAstron detections of the classic quasar 3C273 on interferometric baselines up to 171,000 km suggest brightness temperatures exceeding expected limits from the "inverse-Compton catastrophe" by two orders of magnitude. We show that at 18 cm, these estimates most probably arise from refractive substructure introduced by scattering in the interstellar medium. We use the scattering properties to estimate an intrinsic brightness temperature of 7*10^12 K, which is consistent with expected theoretical limits, but which is ~15 times lower than estimates that neglect substructure. At 6 cm, the substructure influences the measured values appreciably but gives an estimated brightness temperature that is comparable to models that do not account for the substructure. At 1.3 cm, the substructure does not affect the extremely high inferred brightness temperatures, in excess of 10^13 K....

  20. Influence of land-atmosphere feedbacks on temperature and precipitation extremes in the GLACE-CMIP5 ensemble

    Science.gov (United States)

    Lorenz, Ruth; Argüeso, Daniel; Donat, Markus G.; Pitman, Andrew J.; Hurk, Bart; Berg, Alexis; Lawrence, David M.; Chéruy, Frédérique; Ducharne, Agnès.; Hagemann, Stefan; Meier, Arndt; Milly, P. C. D.; Seneviratne, Sonia I.

    2016-01-01

    We examine how soil moisture variability and trends affect the simulation of temperature and precipitation extremes in six global climate models using the experimental protocol of the Global Land-Atmosphere Coupling Experiment of the Coupled Model Intercomparison Project, Phase 5 (GLACE-CMIP5). This protocol enables separate examinations of the influences of soil moisture variability and trends on the intensity, frequency, and duration of climate extremes by the end of the 21st century under a business-as-usual (Representative Concentration Pathway 8.5) emission scenario. Removing soil moisture variability significantly reduces temperature extremes over most continental surfaces, while wet precipitation extremes are enhanced in the tropics. Projected drying trends in soil moisture lead to increases in intensity, frequency, and duration of temperature extremes by the end of the 21st century. Wet precipitation extremes are decreased in the tropics with soil moisture trends in the simulations, while dry extremes are enhanced in some regions, in particular the Mediterranean and Australia. However, the ensemble results mask considerable differences in the soil moisture trends simulated by the six climate models. We find that the large differences between the models in soil moisture trends, which are related to an unknown combination of differences in atmospheric forcing (precipitation, net radiation), flux partitioning at the land surface, and how soil moisture is parameterized, imply considerable uncertainty in future changes in climate extremes.

  1. The Effect of Water Temperature during Cold-Water Immersion on Recovery from Exercise-Induced Muscle Damage.

    Science.gov (United States)

    Vieira, A; Siqueira, A F; Ferreira-Junior, J B; do Carmo, J; Durigan, J L Q; Blazevich, A; Bottaro, M

    2016-11-01

    This study investigated the effects of 5 and 15°C cold-water immersion on recovery from exercise resulting in exercise-induced muscle damage. 42 college-aged men performed 5×20 drop-jumps and were randomly allocated into one of 3 groups: (1) 5°C; (2) 15°C; or (3) control. After exercise, individuals from the cold-water immersion groups had their lower limbs immerged in iced water for 20 min. Isometric knee extensor torque, countermovement jump, muscle soreness, and creatine kinase were measured before, immediately after, 24, 48, 72, 96 and 168 h post-exercise. There was no between-group difference in isometric strength recovery (p=0.73). However, countermovement jump recovered quicker in cold-water immersion groups compared to control group (pmuscle soreness (p=0.06) in 15°C group compared to control at 24 h post-exercise. The result suggests that cold-water immersion promote recovery of stretch-shortening cycle performance, but not influence the recovery of maximal contractile force. Immersion at warmer temperature may be more effective than colder temperatures promoting recovery from strenuous exercise. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Rhodotorula mucilaginosa BPT1 can form arthrospore in response to cold-temperature

    Institute of Scientific and Technical Information of China (English)

    Sahay Sanjay; Abdul Mazid Khan; Majid Butt; Tekram Sahu; Ravinder S Rana; Deepak Chouhan; Kamlesh Ranjan; Burhan Hamid

    2014-01-01

    Objective: To study carbon and nitrogen utilization pattern and arthrospore formation in a psychrotolerant yeast isolate Rhodotorula mucilaginosa (R. mucilaginosa) BPT1. Methods:Growth of the yeast on minimal synthetic medium supplemented with various carbon and nitrogen compounds as sole carbon or nitrogen source has been studied. Various physico-chemical parameters such as pH, restricted oxygen supply, temperatures, media composition and presence of methionine were tested to examine their effect on arthrospore formation by this known opportunistic pathogen. Results: The psychrotolerant isolate BPT1 identified on the basis of D1/D2 domain of large rDNA sequence characteristics as R. mucilaginosa showed some deviation in carbon and nitrogen utilization patterns from those of other strains of R. mucilaginosa in the CBS data base. Intriguingly, the isolate produced sub-surface hyphal rays around its colony at lower temperatures (4 °C and 20 °C) on PDA medium; the ray was found to be linearly arranged arthrospores. The arthrospore was not produced in liquid medium, or in presence of methionine or under micro-aerobic condition or at higher temperature. Conclusions: The investigation showed a novel feature i.e. arthrospore was formed by this yeast isolate under specific set of conditions. The results reiterated that only physiological and morphological characteristics were not sufficient to identify a yeast. The ability of R. mucilaginosa to form arthrospores seems to be an adaptive feature in response to extreme environmental condition, and represents adaptive ability having something to do with its ubiquity.

  3. Manipulation of Samples at Extreme Temperatures for Fast in-situ Synchrotron Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Weber, Richard [Materials Development, Inc., Arlington Heights, IL (United States)

    2016-04-22

    An aerodynamic sample levitation system with laser beam heating was integrated with the APS beamlines 6 ID-D, 11 ID-C and 20 BM-B. The new capability enables in-situ measurements of structure and XANES at extreme temperatures (300-3500 °C) and in conditions that completely avoid contact with container surfaces. In addition to maintaining a high degree of sample purity, the use of aerodynamic levitation enables deep supercooling and greatly enhanced glass formation from a wide variety of melts and liquids. Development and integration of controlled extreme sample environments and new measurement techniques is an important aspect of beamline operations and user support. Processing and solidifying liquids is a critical value-adding step in manufacturing semiconductors, optical materials, metals and in the operation of many energy conversion devices. Understanding structural evolution is of fundamental importance in condensed materials, geology, and biology. The new capability provides unique possibilities for materials research and helps to develop and maintain a competitive materials manufacturing and energy utilization industry. Test samples were used to demonstrate key features of the capability including experiments on hot crystalline materials, liquids at temperatures from about 500 to 3500 °C. The use of controlled atmospheres using redox gas mixtures enabled in-situ changes in the oxidation states of cations in melts. Significant innovations in this work were: (i) Use of redox gas mixtures to adjust the oxidation state of cations in-situ (ii) Operation with a fully enclosed system suitable for work with nuclear fuel materials (iii) Making high quality high energy in-situ x-ray diffraction measurements (iv) Making high quality in-situ XANES measurements (v) Publishing high impact results (vi) Developing independent funding for the research on nuclear materials This SBIR project work led to a commercial instrument product for the niche market of processing and

  4. Characterizing the Chemical Stability of High Temperature Materials for Application in Extreme Environments

    Science.gov (United States)

    Opila, Elizabeth

    2005-01-01

    The chemical stability of high temperature materials must be known for use in the extreme environments of combustion applications. The characterization techniques available at NASA Glenn Research Center vary from fundamental thermodynamic property determination to material durability testing in actual engine environments. In this paper some of the unique techniques and facilities available at NASA Glenn will be reviewed. Multiple cell Knudsen effusion mass spectrometry is used to determine thermodynamic data by sampling gas species formed by reaction or equilibration in a Knudsen cell held in a vacuum. The transpiration technique can also be used to determine thermodynamic data of volatile species but at atmospheric pressures. Thermodynamic data in the Si-O-H(g) system were determined with this technique. Free Jet Sampling Mass Spectrometry can be used to study gas-solid interactions at a pressure of one atmosphere. Volatile Si(OH)4(g) was identified by this mass spectrometry technique. A High Pressure Burner Rig is used to expose high temperature materials in hydrocarbon-fueled combustion environments. Silicon carbide (SiC) volatility rates were measured in the burner rig as a function of total pressure, gas velocity and temperature. Finally, the Research Combustion Lab Rocket Test Cell is used to expose high temperature materials in hydrogen/oxygen rocket engine environments to assess material durability. SiC recession due to rocket engine exposures was measured as a function of oxidant/fuel ratio, temperature, and total pressure. The emphasis of the discussion for all techniques will be placed on experimental factors that must be controlled for accurate acquisition of results and reliable prediction of high temperature material chemical stability.

  5. Wire and Cable Cold Bending Test

    Science.gov (United States)

    Colozza, Anthony

    2010-01-01

    One of the factors in assessing the applicability of wire or cable on the lunar surface is its flexibility under extreme cold conditions. Existing wire specifications did not address their mechanical behavior under cold, cryogenic temperature conditions. Therefore tests were performed to provide this information. To assess this characteristic 35 different insulated wire and cable pieces were cold soaked in liquid nitrogen. The segments were then subjected to bending and the force was recorded. Any failure of the insulation or jacketing was also documented for each sample tested. The bending force tests were performed at room temperature to provide a comparison to the change in force needed to bend the samples due to the low temperature conditions. The results from the bending tests were plotted and showed how various types of insulated wire and cable responded to bending under cold conditions. These results were then used to estimate the torque needed to unroll the wire under these low temperature conditions.

  6. Parameterizing Aggregation Rates: Results of cold temperature ice-ash hydrometeor experiments

    Science.gov (United States)

    Courtland, L. M.; Dufek, J.; Mendez, J. S.; McAdams, J.

    2014-12-01

    Recent advances in the study of tephra aggregation have indicated that (i) far-field effects of tephra sedimentation are not adequately resolved without accounting for aggregation processes that preferentially remove the fine ash fraction of volcanic ejecta from the atmosphere as constituent pieces of larger particles, and (ii) the environmental conditions (e.g. humidity, temperature) prevalent in volcanic plumes may significantly alter the types of aggregation processes at work in different regions of the volcanic plume. The current research extends these findings to explore the role of ice-ash hydrometeor aggregation in various plume environments. Laboratory experiments utilizing an ice nucleation chamber allow us to parameterize tephra aggregation rates under the cold (0 to -50 C) conditions prevalent in the upper regions of volcanic plumes. We consider the interaction of ice-coated tephra of variable thickness grown in a controlled environment. The ice-ash hydrometers interact collisionally and the interaction is recorded by a number of instruments, including high speed video to determine if aggregation occurs. The electric charge on individual particles is examined before and after collision to examine the role of electrostatics in the aggregation process and to examine the charge exchange process. We are able to examine how sticking efficiency is related to both the relative abundance of ice on a particle as well as to the magnitude of the charge carried by the hydrometeor. We here present preliminary results of these experiments, the first to constrain aggregation efficiency of ice-ash hydrometeors, a parameter that will allow tephra dispersion models to use near-real-time meteorological data to better forecast particle residence time in the atmosphere.

  7. Evolution of magnetic phase at low aging temperature in a heavily cold-drawn stainless steel fiber

    Science.gov (United States)

    Yang, Shun-Tung; Hwang, Weng-Sing; Shyr, Tien-Wei; Cheng, I.-Lin

    2012-08-01

    The evolution of the magnetic phase upon aging at 300-520 °C in a heavily cold-drawn AISI 316L austenitic stainless steel fiber was studied using thermomagnetic analysis (TMA) and magnetic force microscopy with a heating stage. An increasing trend of magnetization from 50 °C to around 470 °C in the heating curves of TMA in austenitic stainless steels after a cold-drawing process was observed. No significant Ms temperature signal in the TMA curve at cooling indicated an increase in magnetization upon cooling period without significant phase transformation. A series of in situ magnetic force microscopy observations reveal a growth of the magnetic domain structure after aging at 300 °C for 2.5 h. Results show that the ferromagnetic increase during aging at lower annealing temperature resulted from the growth of martensite.

  8. Extreme temperatures, foundation species, and abrupt ecosystem change: an example from an iconic seagrass ecosystem.

    Science.gov (United States)

    Thomson, Jordan A; Burkholder, Derek A; Heithaus, Michael R; Fourqurean, James W; Fraser, Matthew W; Statton, John; Kendrick, Gary A

    2015-04-01

    Extreme climatic events can trigger abrupt and often lasting change in ecosystems via the reduction or elimination of foundation (i.e., habitat-forming) species. However, while the frequency/intensity of extreme events is predicted to increase under climate change, the impact of these events on many foundation species and the ecosystems they support remains poorly understood. Here, we use the iconic seagrass meadows of Shark Bay, Western Australia--a relatively pristine subtropical embayment whose dominant, canopy-forming seagrass, Amphibolis antarctica, is a temperate species growing near its low-latitude range limit--as a model system to investigate the impacts of extreme temperatures on ecosystems supported by thermally sensitive foundation species in a changing climate. Following an unprecedented marine heat wave in late summer 2010/11, A. antarctica experienced catastrophic (>90%) dieback in several regions of Shark Bay. Animal-borne video footage taken from the perspective of resident, seagrass-associated megafauna (sea turtles) revealed severe habitat degradation after the event compared with a decade earlier. This reduction in habitat quality corresponded with a decline in the health status of largely herbivorous green turtles (Chelonia mydas) in the 2 years following the heat wave, providing evidence of long-term, community-level impacts of the event. Based on these findings, and similar examples from diverse ecosystems, we argue that a generalized framework for assessing the vulnerability of ecosystems to abrupt change associated with the loss of foundation species is needed to accurately predict ecosystem trajectories in a changing climate. This includes seagrass meadows, which have received relatively little attention in this context. Novel research and monitoring methods, such as the analysis of habitat and environmental data from animal-borne video and data-logging systems, can make an important contribution to this framework.

  9. A materials perspective on Li-ion batteries at extreme temperatures

    Science.gov (United States)

    Rodrigues, Marco-Tulio F.; Babu, Ganguli; Gullapalli, Hemtej; Kalaga, Kaushik; Sayed, Farheen N.; Kato, Keiko; Joyner, Jarin; Ajayan, Pulickel M.

    2017-08-01

    With the continuous upsurge in demand for energy storage, batteries are increasingly required to operate under extreme environmental conditions. Although they are at the technological forefront, Li-ion batteries have long been limited to room temperature, as internal phenomena during their operation cause thermal fluctuations. This has been the reason for many battery explosions in recent consumer products. While traditional efforts to address these issues focused on thermal management strategies, the performance and safety of Li-ion batteries at both low (60 °C) temperatures are inherently related to their respective components, such as electrode and electrolyte materials and the so-called solid-electrolyte interphases. This Review examines recent research that considers thermal tolerance of Li-ion batteries from a materials perspective, spanning a wide temperature spectrum (‑60 °C to 150 °C). The structural stability of promising cathodes, issues with anode passivation, and the competency of various electrolyte, binder and current collectors are compared for their thermal workability. The possibilities offered by each of these cell components could extend the environmental frontiers of commercial Li-ion batteries.

  10. Modified and double-clad large mode-area leakage channel fibers for extreme temperature conditions

    Science.gov (United States)

    Thavasi Raja, G.; Varshney, Shailendra K.

    2015-03-01

    Recently large-mode-area hybrid leakage channel fibers (HLCFs) were reported to overcome the limitation on mode area with single-mode (SM) operation for the practical bending radius of 7.5 cm at the preferred wavelength of 1064 nm. In this paper, we present the effects of a thermally induced refractive index change on the mode area of bend-compensated extremely LMA modified HLCFs (M-HLCFs) and double-clad M-HLCFs. A full-vectorial finite-element method-based modal solver is used to obtain the modal characteristics of M-HLCFs in various heat load conditions. Numerical simulations reveal that the effective mode area of M-HLCFs is ˜1433 μm2 at room temperature, which marginally decreases to ˜1387 μm2 while SM operation is maintained when the temperature distribution rises to ˜125 °C over the fiber geometry during high-power operations. We have also investigated a double-clad M-HLCF design exhibiting a mode area > ˜ 1000 μm2 for all heat load density variations up to a maximum of 12 × 109 W m-3, corresponding to a 250 °C temperature in the center of the fiber core region.

  11. Low-pressure systems and extreme precipitation in central India: sensitivity to temperature changes

    Science.gov (United States)

    Sørland, Silje Lund; Sorteberg, Asgeir

    2016-07-01

    Extreme rainfall events in the central Indian region are often related to the passage of synoptic scale monsoon low-pressure systems (LPS). This study uses the surrogate climate change method on ten monsoon LPS cases connected to observed extreme rainfall events, to investigate how sensitive the precipitation and runoff are to an idealized warmer and moister atmosphere. The ten cases are simulated with three different initial and lateral boundary conditions: the unperturbed control run, and two sets of perturbed runs where the atmospheric temperature is increased uniformly throughout the atmosphere, the specific humidity increased according to Clausius Clapeyron's relation, but the large-scale flow is unchanged. The difference between the control and perturbed simulations are mainly due to the imposed warming and feedback influencing the synoptic flow. The mean precipitation change with warming in the central Indian region is 18-20 %/K, with largest changes at the end of the LPS tracks. The LPS in the warmer runs are bringing more moisture further inland that is released as precipitation. In the perturbed runs the precipitation rate is increasing at all percentiles, and there is more frequent rainfall with very heavy intensities. This leads to a shift in which category that contributes most to the total precipitation: more of the precipitation is coming from the category with very heavy intensities. The runoff changes are similar to the precipitation changes, except the response in intensity of very heavy runoff, which is around twice the change in intensity of very heavy precipitation.

  12. Extreme High and Low Temperature Operation of the Silicon-On-Insulator Type CHT-OPA Operational Amplifier

    Science.gov (United States)

    Patterson, Richard; Hammoud, Ahmad; Elbuluk, Malik

    2008-01-01

    A new operational amplifier chip based on silicon-on-insulator technology was evaluated for potential use in extreme temperature environments. The CHT-OPA device is a low power, precision operational amplifier with rail-to-rail output swing capability, and it is rated for operation between -55 C and +225 C. A unity gain inverting circuit was constructed utilizing the CHT-OPA chip and a few passive components. The circuit was evaluated in the temperature range from -190 C to +200 C in terms of signal gain and phase shift, and supply current. The investigations were carried out to determine suitability of this device for use in space exploration missions and aeronautic applications under wide temperature incursion. Re-restart capability at extreme temperatures, i.e. power switched on while the device was soaked at extreme temperatures, was also investigated. In addition, the effects of thermal cycling under a wide temperature range on the operation of this high performance amplifier were determined. The results from this work indicate that this silicon-on-insulator amplifier chip maintained very good operation between +200 C and -190 C. The limited thermal cycling had no effect on the performance of the amplifier, and it was able to re-start at both -190 C and +200 C. In addition, no physical degradation or packaging damage was introduced due to either extreme temperature exposure or thermal cycling. The good performance demonstrated by this silicon-on-insulator operational amplifier renders it a potential candidate for use in space exploration missions or other environments under extreme temperatures. Additional and more comprehensive characterization is, however, required to establish the reliability and suitability of such devices for long term use in extreme temperature applications.

  13. Thermodynamic Properties of Gaseous Plasmas in the Limit of Extremely Low Temperature

    CERN Document Server

    Iosilevskiy, Igor

    2010-01-01

    Limiting structure of thermodynamic functions of gaseous plasmas is under consideration in the limit of zero temperature and density. Remarkable tendency, which was claimed previously (Iosilevskiy and Gryaznov, 1985) is carried to extreme. Both equations of state, thermal and caloric ones obtain in this limit identical stepped structure ("ionization stairs") for plasma of any single element when this limit (T -> 0, n -> 0) is carried out at fixed value of chemical potential for electrons (or atoms). The same stepped structure is valid for plasma of mixtures or compounds. This structure appears within a fixed (negative) range of chemical potential of electrons bounded below by value of major ionization potential of element and above by the value depending on sublimation energy of substance. Binding energies of all possible bound complexes (atomic, molecular, ionic and clusters) in its ground state are the only quantities that manifest itself in meaningful details of this limiting picture as location and value ...

  14. On regional dynamical downscaling for the assessment and projection of temperature and precipitation extremes across Tasmania, Australia

    Science.gov (United States)

    White, Christopher J.; McInnes, Kathleen L.; Cechet, Robert P.; Corney, Stuart P.; Grose, Michael R.; Holz, Gregory K.; Katzfey, Jack J.; Bindoff, Nathaniel L.

    2013-12-01

    The ability of an ensemble of six GCMs, downscaled to a 0.1° lat/lon grid using the Conformal Cubic Atmospheric Model over Tasmania, Australia, to simulate observed extreme temperature and precipitation climatologies and statewide trends is assessed for 1961-2009 using a suite of extreme indices. The downscaled simulations have high skill in reproducing extreme temperatures, with the majority of models reproducing the statewide averaged sign and magnitude of recent observed trends of increasing warm days and warm nights and decreasing frost days. The warm spell duration index is however underestimated, while variance is generally overrepresented in the extreme temperature range across most regions. The simulations show a lower level of skill in modelling the amplitude of the extreme precipitation indices such as very wet days, but simulate the observed spatial patterns and variability. In general, simulations of dry extreme precipitation indices are underestimated in dryer areas and wet extremes indices are underestimated in wetter areas. Using two SRES emissions scenarios, the simulations indicate a significant increase in warm nights compared to a slightly more moderate increase in warm days, and an increase in maximum 1- and 5- day precipitation intensities interspersed with longer consecutive dry spells across Tasmania during the twenty-first century.

  15. Biodiversity and geochemistry of an extremely acidic, low-temperature subterranean environment sustained by chemolithotrophy.

    Science.gov (United States)

    Kimura, Sakurako; Bryan, Christopher G; Hallberg, Kevin B; Johnson, D Barrie

    2011-08-01

    The geochemical dynamics and composition of microbial communities within a low-temperature (≈ 8.5°C), long-abandoned (> 90 years) underground pyrite mine (Cae Coch, located in north Wales) were investigated. Surface water percolating through fractures in the residual pyrite ore body that forms the roof of the mine becomes extremely acidic and iron-enriched due to microbially accelerated oxidative dissolution of the sulfide mineral. Water droplets on the mine roof were found to host a very limited diversity of exclusively autotrophic microorganisms, dominated by the recently described psychrotolerant iron/sulfur-oxidizing acidophile Acidithiobacillus ferrivorans, and smaller numbers of iron-oxidizing Leptospirillum ferrooxidans. In contrast, flowing water within the mine chamber was colonized with vast macroscopic microbial growths, in the form of acid streamers and microbial stalactites, where the dominant microorganisms were Betaproteobacteria (autotrophic iron oxidizers such as 'Ferrovum myxofaciens' and a bacterium related to Gallionella ferruginea). An isolated pool within the mine showed some similarity (although greater biodiversity) to the roof droplets, and was the only site where archaea were relatively abundant. Bacteria not previously associated with extremely acidic, metal-rich environments (a Sphingomonas sp. and Ralstonia pickettii) were found within the abandoned mine. Data supported the hypothesis that the Cae Coch ecosystem is underpinned by acidophilic, mostly autotrophic, bacteria that use ferrous iron present in the pyrite ore body as their source of energy, with a limited role for sulfur-based autotrophy. Results of this study highlight the importance of novel bacterial species (At. ferrivorans and acidophilic iron-oxidizing Betaproteobacteria) in mediating mineral oxidation and redox transformations of iron in acidic, low-temperature environments. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  16. Climate change scenarios of extreme temperatures and atmospheric humidity for Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Tejeda-Martinez, A. [Departamento de Ciencias Atmosfericas, Universidad Veracruzana, Xalapa, Veracruz (Mexico)]. E-mail: atejeda@uv.mx; Conde-Alvarez, C. [Centro de Ciencias de la Atmosfera, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Valencia-Treviso, L.E. [Departamento de Ciencias Atmosfericas, Universidad Veracruzana, Xalapa, Veracruz (Mexico)

    2008-10-15

    The following study explores climatic change scenarios of extreme temperature and atmospheric humidity for the 2020 and 2050 decades. They were created for Mexico through the GFDLR30, ECHAM4 and HadCM2 general circulation models. Base scenario conditions were associated with the normal climatological conditions for the period 1961-1990, with a database of 50 surface observatories. It was necessary to empirically estimate the missing data in approximately half of the pressure measurements. For the period 1961-1990, statistical models of the monthly means of maximum and minimum temperatures and atmospheric humidity (relative and specific) were obtained from the observed data of temperature, solar radiation and precipitation. Based on the simulations of the GFDLR30, ECHAM4 and HADCM2 models, a future scenario of monthly means of maximum and minimum temperatures and humidity in climatic change conditions was created. The results shown are for the representative months of winter (January) and summer (July). [Spanish] En este articulo se presentan escenarios de cambio climatico referidos a temperaturas extremas y humedad atmosferica para las decadas de 2020 y 2050. Fueron generados para Mexico a partir de los modelos de circulacion general GFDLR30, ECHAM4 y HADCM2. El escenario base corresponde a las normales climatologicas del periodo 1961-1990 para 50 observatorios de superficie. Para la mitad de ellos fue necesario estimar empiricamente la presion atmosferica a partir de la altitud y para la totalidad se obtuvieron modelos estadisticos de los promedios mensuales de temperaturas maxima y minima asi como de humedad atmosferica (relativa y especifica). Esos modelos estadisticos, combinados con las salidas de los modelos de circulacion general mencionados, produjeron escenarios futuros de medias mensuales de temperaturas extremas y de humedad bajo condiciones de cambio climatico. Se mostraran los resultados para un mes representativo del invierno (enero) y otro del verano

  17. CHANGES IN FREQUENCY, PERSISTENCE AND INTENSITY OF EXTREME HIGH-TEMPERATURE EVENTS IN THE ROMANIAN PLAIN

    Directory of Open Access Journals (Sweden)

    DRAGOTĂ CARMEN-SOFIA

    2015-03-01

    Full Text Available Recent summer heat waves (2003, 2010 had a strong socio-economic impact in different parts of the continent by means of crop shortfalls and forest fires. Sustained hot days became more frequent in the recent decades in many European regions, affecting human health and leading to additional deaths. This signal has been outlined in many studies conducted in Romania, suggesting that the southern region of Romania is particularly subject to large temperature increase. This work investigates the changing annual and seasonal heat waves at regional scale of the Romanian Plain, over period 1961-2014. Daily maximum temperature recorded at six weather stations available from the ECA&D project (European Climate Assessment and Datasets were analyzed. The changes in the seasonal frequency, duration and intensity of heat waves were studied using the Mann-Kendall nonparametric trend test, as recommended by the scientific expert team on climate change detection. The likelyhood of higher maximum temperatures rise, particularly after the mid 1980s, and the changes in the upper tail of the probability density functions of these temperatures, within the extreme domain (beyond the 95% percentile level, explain the persistence and intensity of heat waves. The upward trends are dominant most of the year, and many of the calculated decadal slopes were found statistically significant (relative to the 5% level, proving an ongoing and strong warming all over the region. Our findings are in good agreement with several recent studies carried out at European and national scale and pledge for further scientific analyses i.e. heat stress impact on public health and agriculture.

  18. Multi-scenario-based hazard analysis of high temperature extremes experienced in China during 1951-2010

    Institute of Scientific and Technical Information of China (English)

    YIN Zhan'e; YIN Jie; ZHANG Xiaowei

    2013-01-01

    China is physically and socio-economically susceptible to global warming-derived high temperature extremes because of its vast area and high urban population density.This article presents a scenario-based analysis method for high temperature extremes aimed at illustrating the latter's hazardous potential and exposure across China.Based on probability analysis,high temperature extreme scenarios with return periods of 5,10,20,and 50 years were designed,with a high temperature hazard index calculated by integrating two differentially-weighted extreme temperature indices (maximum temperature and high temperature days).To perform the exposure analysis,a land use map was employed to determine the spatial distribution of susceptible human activities under the different scenarios.The results indicate that there are two heat-prone regions and a sub-hotspot occupying a relatively small land area.However,the societal and economic consequences of such an environmental impact upon the North China Plain and middle/lower Yangtze River Basin would be substantial due to the concentration of human activities in these areas.

  19. Conduccion de lombricultivos en condiciones de temperie extremas (zonas frias - Vermiculture management in extreme weather conditions (cold areas

    Directory of Open Access Journals (Sweden)

    Miguel SCHULDT

    2006-07-01

    Full Text Available Para optimizar la conducción de vermicultivos en climas fríos y condiciones de temperie se recomienda implementar durante la primavera – verano, alimentación periódica (semanal que se inicia con una siembra de 10.000 lombrices / Lecho (2 m2. Tras una subdivisión del cultivo en el verano y el despoblamiento de los sectores en el otoño, las lombrices obtenidas se utilizan para poblar sectores de materia orgánica (MO de 1,5 m de altura a razón de 4.000 lombrices / Lecho, donde permanecerán hasta la primavera siguiente. Esta modalidad de manejo, al cabo de un año, permite potencialmente multiplicar elc área de cultivo en aproximadamente 150 veces el inicial y paralelamente aumentar el tamaño de la población de lombrices 1.470 veces. Esta producción de lombrices corresponde al 31% de la potencialmente alcanzable en climas moderados (4.800X. In order to optimize vermiculture management in cold climates, it is recommended to implement periodic (weekly feeding during spring - summer, beginning with the inoculation of 10,000 worms/Bed (2 m2. After subdivision of the culture in summer and extraction of earthworms from the sectors in autumn, the obtained worms are used to populate new sectors with 1.5 m high organic matter (OM piles at a rate of 4,000 worms/Bed, where they are kept until the following spring. After one year, this management method allows a potential 150-fold increase of the original culture area and a simultaneous growth of the earthworm population to 1,470 times its initial size. This earthworm production represents 31% of the potential production for moderate climates (4.800X

  20. Analysis and Comparison of Trends in Extreme Temperature Indices in Riyadh City, Kingdom of Saudi Arabia, 1985–2010

    OpenAIRE

    Ali S. Alghamdi; Todd W. Moore

    2014-01-01

    This study employed the time series of thirteen extreme temperature indices over the period 1985–2010 to analyze and compare temporal trends at two weather stations in Riyadh city, Saudi Arabia. The trend analysis showed warming of the local air for the city. Significant increasing trends were found in annual average maximum and minimum temperatures, maximum of minimum temperature, warm nights, and warm days for an urban and a rural station. Significant decreasing trends were detected in the ...

  1. Response of Bacillus subtilis spores to dehydration and UV irradiation at extremely low temperatures.

    Science.gov (United States)

    Dose, K; Klein, A

    1996-02-01

    Spores of Bacillus subtilis have been exposed to the conditions of extreme dehydration (argon/silica gel; simulated space vacuum) for up to 12 weeks at 298 K and 80 K in the dark. The inactivation has been correlated with the production of DNA-double strand-breaks. The temperature-dependence of the rate constants for inactivation or production of DNA-double strand-breaks is surprisingly low. Controls kept in the frozen state at 250 K for the same period of time showed no sign of deterioration. In another series of experiments the spores have been UV irradiated (253.7 nm) at 298 K, 200 K and 80 K after exposure to dehydrating conditions for 3 days. Fluence-effect relationships for inactivation, production of DNA-double strand-breaks and DNA-protein cross-links are presented. The corresponding F37-values for inactivation and production of DNA lesions are significantly increased only at 80 K (factor of 4 to 5). The data indicate that the low temperatures that prevail in the outer parts of the Solar System or at the nightside of Mars or the Moon are not sufficiently low to crucially inhibit inactivation by dehydration. Our data place further constraints on the panspermia hypothesis.

  2. Short-term cropland responses to temperature extreme events during late winter

    Directory of Open Access Journals (Sweden)

    G. De Simon

    2013-04-01

    Full Text Available In recent years, several studies have focused on terrestrial ecosystem response to extreme events. Most of this research has been conducted in natural ecosystems, but few have considered agro-ecosystems. In this study, we investigated the impact of a manipulated warmer or cooler late winter-early spring on the carbon budget and final harvest of a soybean crop (Glycine max (L. Merr.. Soil temperature was altered by manipulating soil albedo by covering the soil surface with a layer of inert silica gravel. We tested three treatments: cooling (Co, warming (W, mix (M and control (C. An automated system continuously measured soil heterotrophic respiration (Rh, soil temperature profiles, and soil water content across the entire year in each plot. Phenological phases were periodically assessed and final harvest was measured in each plot. Results showed that treatments had only a transient effect on daily Rh rates which did not result in a total annual carbon budget significantly different from control, even though cooling showed a significant reduction in final harvest. We also observed anticipation in seed germination in both W and M treatments and a delay in germination for Co. Moreover, plant density and growth increased in W and M and decreased in Co.

  3. Simulation evaluation and future prediction of the IPCC-AR4 GCMs on the extreme temperatures in China

    Institute of Scientific and Technical Information of China (English)

    WANG Ji; JIANG Zhihong; SONG Jie; LOU Dejun

    2008-01-01

    On the basis of the temperature observations during 1961-2000 in China, seven coupled general circulation models' (GCMs) extreme temperature products are evaluated supplied by the Intergovemmental Panel on Climate Change's 4th Assessment Report (IPCC-AR4). The extreme temperature indices in use are frost days (FD), growing season length (GSL), extreme tempera-ture range (ETR), warm nights (TN90), and heat wave duration index (HWDI). Results indicate that all the seven models are capable of simulating spatial and temporal variations in temperature characteristics, and their ensemble acts more reliable than any single one. Among the seven models, GFDL-CM2.0 and MIROC3.2 performances are much better. Besides, most of the mod-els are able to present linear trends of the same positive/negative signs as the observations but for weaker intensities. The simula-tion effects are different on a nationwide basis, with 110°N as the division, east (west) of which the effects are better (worse) and the poorer over the Qinghai-Tibetan Plateau in China. The predictions for the 21st century on emissions scenarios show that except decreases in the FD and ETR, other indices display significant increasing trend, especially for the indices of HWDI and TN90, which represent the notable extreme climate. This indicates that the temperature-related climate is moving towards the ex-treme. In the late 21st century, the GSL and TN90 (HWDI) increase most notably in southwest China (the Qinghai--Tibetan Plateau), and the FD decrease most remarkably in the Qinghai-Tibetan Plateau, northwest and northeast of China. Apart from South China, the yearly change range of the extreme temperature is reduced in most of China.

  4. Investigating temperature breaks in the summer fruit export cold chain - a case study

    CSIR Research Space (South Africa)

    Freiboth, HW

    2013-11-01

    Full Text Available arrives. The fruit is then transported to the port for export to the destination market where it will be offered to the consumer. If the duration of the road transport segment from the pack house to the port of export exceeds two hours, the Perishable... and pears have a longer shelf life than grapes and can be held in cold storage for longer periods, depending on market conditions. Freshly harvested apples and pears are typically transferred to a regional pack house and cold store, they are then force...

  5. Proteomic Characterization of Inbreeding-Related Cold Sensitivity in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Vermeulen, C.J.; Pedersen, Kamilla Sofie; Beck, Hans C.

    2013-01-01

    insight into the molecular interplay between intrinsic stress responses, inbreeding depression and temperature tolerance, we performed a proteomic characterization of a well-defined conditional inbreeding effect in a single line of Drosophila melanogaster, which suffers from extreme cold sensitivity...

  6. Selective blockade of TRPA1 channel attenuates pathological pain without altering noxious cold sensation or body temperature regulation.

    Science.gov (United States)

    Chen, Jun; Joshi, Shailen K; DiDomenico, Stanley; Perner, Richard J; Mikusa, Joe P; Gauvin, Donna M; Segreti, Jason A; Han, Ping; Zhang, Xu-Feng; Niforatos, Wende; Bianchi, Bruce R; Baker, Scott J; Zhong, Chengmin; Simler, Gricelda H; McDonald, Heath A; Schmidt, Robert G; McGaraughty, Steve P; Chu, Katharine L; Faltynek, Connie R; Kort, Michael E; Reilly, Regina M; Kym, Philip R

    2011-05-01

    Despite the increasing interest in TRPA1 channel as a pain target, its role in cold sensation and body temperature regulation is not clear; the efficacy and particularly side effects resulting from channel blockade remain poorly understood. Here we use a potent, selective, and bioavailable antagonist to address these issues. A-967079 potently blocks human (IC(50): 51 nmol/L, electrophysiology, 67 nmol/L, Ca(2+) assay) and rat TRPA1 (IC(50): 101 nmol/L, electrophysiology, 289 nmol/L, Ca(2+) assay). It is >1000-fold selective over other TRP channels, and is >150-fold selective over 75 other ion channels, enzymes, and G-protein-coupled receptors. Oral dosing of A-967079 produces robust drug exposure in rodents, and exhibits analgesic efficacy in allyl isothiocyanate-induced nocifensive response and osteoarthritic pain in rats (ED(50): 23.2 mg/kg, p.o.). A-967079 attenuates cold allodynia produced by nerve injury but does not alter noxious cold sensation in naive animals, suggesting distinct roles of TRPA1 in physiological and pathological states. Unlike TRPV1 antagonists, A-967079 does not alter body temperature. It also does not produce locomotor or cardiovascular side effects. Collectively, these data provide novel insights into TRPA1 function and suggest that the selective TRPA1 blockade may present a viable strategy for alleviating pain without untoward side effects. Copyright © 2011 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  7. ANALISA MASA SIMPAN RENDANG IKAN TUNA DALAM KEMASAN VAKUM SELAMA PENYIMPANAN PADA SUHU RUANG DAN DINGIN Analysis of The Shelf Life of Tuna Fish as Rendang With Vacuum Packaging at Room Temperature Storage and Cold Temperatures

    OpenAIRE

    RAHMADANA.S

    2013-01-01

    2013 The objective of this research was to determine how many days the self life of rendang tuna which is packed normall and by using vacuum method at room temperature and cold storage and to determine the quality of rendang tuna which was packed normall and by using vacuum method at room temperature and cold storage. The treatment used in this study was A1B1(normall packaging stored at room temperature), A1B2 (normally packaging stored at cold temperature), A2B1 (vacuum packaging stored a...

  8. Lysosomal responses to heat-shock of seasonal temperature extremes in Cd-exposed mussels.

    Science.gov (United States)

    Múgica, M; Izagirre, U; Marigómez, I

    2015-07-01

    The present study was aimed at determining the effect of temperature extremes on lysosomal biomarkers in mussels exposed to a model toxic pollutant (Cd) at different seasons. For this purpose, temperature was elevated 10°C (from 12°C to 22°C in winter and from 18°C to 28°C in summer) for a period of 6h (heat-shock) in control and Cd-exposed mussels, and then returned back to initial one. Lysosomal membrane stability and lysosomal structural changes in digestive gland were investigated. In winter, heat-shock reduced the labilisation period (LP) of the lysosomal membrane, especially in Cd-exposed mussels, and provoked transient lysosomal enlargement. LP values recovered after the heat-shock cessation but lysosomal enlargement prevailed in both experimental groups. In summer, heat-shock induced remarkable reduction in LP and lysosomal enlargement (more markedly in Cd-exposed mussels), which recovered within 3 days. Besides, whilst heat-shock effects on LP were practically identical for Cd-exposed mussels in winter and summer, the effects were longer-lasting in summer than in winter for control mussels. Thus, lysosomal responsiveness after heat-shock was higher in summer than in winter but recovery was faster as well, and therefore the consequences of the heat shock seem to be more decisive in winter. In contrast, inter-season differences were attenuated in the presence of Cd. Consequently, mussels seem to be better prepared in summer than in winter to stand short periods of abrupt temperature change; this is, however, compromised when mussels are exposed to pollutants such as Cd.

  9. Temperaturas extremas en verano. Implicaciones en salud Extreme temperatures in summer time. Health implications

    Directory of Open Access Journals (Sweden)

    Cristina Linares Gil

    2005-12-01

    Full Text Available El incremento que se ha detectado en las temperaturas estivales en los últimos años, unido las tendencias que se esperan para el clima durante el próximo siglo, hacen prever un aumento en la frecuencia e intensidad de los eventos térmicos extremos, fundamentalmente olas de calor. La clara relación existente entre la temperatura y la mortalidad, hace necesaria una cuantificación para la caracterización de los efectos esperados de la temperatura sobre la mortalidad en las denominadas olas de calor.En este trabajo se presenta una descripción del estado del conocimiento de este problema, haciendo especial referencia a la ola de calor que asoló Europa en el verano de 2003, de cómo se han caracterizado las olas de calor y en base a ello de cuáles son las características que han de tener los planes de alerta y prevención encaminados a minimizar los efectos del calor sobre la salud de la población.The increment that has been detected in summer temperatures in the last years joined to the trends expected to climate for the next century provide an increase in frequency and intensity of the extreme climate events, basically in heat waves. The undoubted relationship between temperature and mortality makes necessary a quantifying in order to characterize the expected effects of temperature over mortality particularly in heat waves.This study show a state-of-the-art review this problem, with a special emphasis in the heat wave that Europe suffered in summer of 2003 and how the heat waves has been characterized until now. Lastly, which are the characteristics that should have the preventive measures designed to minimized the effects of heat waves over population ́s health.

  10. Considerations on Temperature Inversions in the Lower Troposphere in the 2001-2002 Cold Season, South of the Carpathian Mountains

    Directory of Open Access Journals (Sweden)

    Florentina Bărcăcianu

    2014-10-01

    Full Text Available Temperature inversions are characterized by negative vertical thermal gradients (Donciu, 1953, Ţâştea, 1965, Bogdan, 1971, Neacşa, Frimescu, 1981. The most frequent manifestation is in the depression areas because in addition to radiative cooling and better possibility to store cold air invasion, it also takes place the accumulation and of air flow of cold air due to gravity. The area south of the Carpathians, shows depression features, gaining titles like: carpathianbalkanic bucket (Bălescu, 1962, carpathian-balkanic sink (Ion-Bordei, N. 1988. In this space the inversions occupy the entire area, proof being the values from low altitude stations similar to those from mountain peaks, while the middle part of the slope remains wormer.

  11. Local sea surface temperatures add to extreme precipitation in northeast Australia during La Niña

    Science.gov (United States)

    Evans, Jason P.; Boyer-Souchet, Irène

    2012-05-01

    This study examines the role played by high sea surface temperatures around northern Australia, in producing the extreme precipitation which occurred during the strong La Niña in December 2010. These extreme rains produced floods that impacted almost 1,300,000 km2, caused billions of dollars in damage, led to the evacuation of thousands of people and resulted in 35 deaths. Through the use of regional climate model simulations the contribution of the observed high sea surface temperatures to the rainfall is quantified. Results indicate that the large-scale atmospheric circulation changes associated with the La Niña event, while associated with above average rainfall in northeast Australia, were insufficient to produce the extreme rainfall and subsequent flooding observed. The presence of high sea surface temperatures around northern Australia added ˜25% of the rainfall total.

  12. Viscosity of Dysphagia-Oriented Cold-Thickened Beverages: Effect of Setting Time at Refrigeration Temperature

    Science.gov (United States)

    Kim, Sung-Gun; Yoo, Byoungseung

    2015-01-01

    Background: Although extensive literature is available on the viscosity of thickened beverages with food thickeners, no attempt has been made to study the effect of setting time on the viscosity of pudding-like cold-thickened beverages with xanthan gum (XG)-based thickeners by using a rheometer. In particular, it is of considerable practical…

  13. Viscosity of Dysphagia-Oriented Cold-Thickened Beverages: Effect of Setting Time at Refrigeration Temperature

    Science.gov (United States)

    Kim, Sung-Gun; Yoo, Byoungseung

    2015-01-01

    Background: Although extensive literature is available on the viscosity of thickened beverages with food thickeners, no attempt has been made to study the effect of setting time on the viscosity of pudding-like cold-thickened beverages with xanthan gum (XG)-based thickeners by using a rheometer. In particular, it is of considerable practical…

  14. Mechanical behaviour of membrane electrode assembly (MEA during cold start of PEM fuel cell from subzero environment temperature

    Directory of Open Access Journals (Sweden)

    Maher A.R. Sadiq Al-Baghdadi

    2015-01-01

    Full Text Available Durability is one of the most critical remaining issues impeding successful commercialization of broad PEM fuel cell transportation energy applications. Automotive fuel cells are likely to operate with neat hydrogen under load-following or load-levelled modes and be expected to withstand variations in environmental conditions, particularly in the context of temperature and atmospheric composition. In addition, they are also required to survive over the course of their expected operational lifetimes i.e., around 5,500 hrs, while undergoing as many as 30,000 startup/shutdown cycles. Cold start capability and survivability of proton exchange membrane fuel cells (PEM in a subzero environment temperature remain a challenge for automotive applications. A key component of increasing the durability of PEM fuel cells is studying the behaviour of the membrane electrode assembly (MEA at the heart of the fuel cell. The present work investigates how the mechanical behaviour of MEA are influenced during cold start of the PEM fuel cell from subzero environment temperatures. Full three-dimensional, non-isothermal computational fluid dynamics model of a PEM fuel cell has been developed to simulate the stresses inside the PEM fuel cell, which are occurring during fuel cell assembly (bolt assembling, and the stresses arise during fuel cell running due to the changes of temperature and relative humidity. The model is shown to be able to understand the many interacting, complex electrochemical, transport phenomena, and stresses distribution that have limited experimental data.

  15. Evolution of extreme temperature events in short term climate projection for Iberian Peninsula.

    Science.gov (United States)

    Rodriguez, Alfredo; Tarquis, Ana M.; Sanchez, Enrique; Dosio, Alessandro; Ruiz-Ramos, Margarita

    2014-05-01

    Extreme events of maximum and minimum temperatures are a main hazard for agricultural production in Iberian Peninsula. For this purpose, in this study we analyze projections of their evolution that could be valid for the next decade, represented in this study by the 30-year period 2004-2034 (target period). For this purpose two kinds of data were used in this study: 1) observations from the station network of AEMET (Spanish National Meteorological Agency) for five Spanish locations, and 2) simulated data at a resolution of 50 ×50 km horizontal grid derived from the outputs of twelve Regional Climate Models (RCMs) taken from project ENSEMBLES (van der Linden and Mitchell, 2009), with a bias correction (Dosio and Paruolo, 2011; Dosio et al., 2012) regarding the observational dataset Spain02 (Herrera et al., 2012). To validate the simulated climate, the available period of observations was compared to a baseline period (1964-1994) of simulated climate for all locations. Then, to analyze the changes for the present/very next future, probability of extreme temperature events for 2004-2034 were compared to that of the baseline period. Although only minor changes are expected, small variations in variability may have a significant impact in crop performance. The objective of the work is to evaluate the utility of these short term projections for potential users, as for instance insurance companies. References Dosio A. and Paruolo P., 2011. Bias correction of the ENSEMBLES high-resolution climate change projections for use by impact models: Evaluation on the present climate. Journal of Geophysical Research, VOL. 116,D16106, doi:10.1029/2011JD015934 Dosio A., Paruolo P. and Rojas R., 2012. Bias correction of the ENSEMBLES high resolution climate change projections for use by impact models: Analysis of the climate change signal. Journal of Geophysical Research,Volume 117, D17, doi: 0.1029/2012JD017968 Herrera et. al. (2012) Development and Analysis of a 50 year high

  16. Physiological Responses to Firefighting in Extreme Temperatures Do Not Compare to Firefighting in Temperate Conditions

    Directory of Open Access Journals (Sweden)

    Stephanie Windisch

    2017-08-01

    Full Text Available Purpose: The aim of this study was to examine physiological responses to two different simulated firefighting exercises: a firefighting exercise with flashovers, smoke, poor visibility and extreme temperatures (300° in a burning container and a standard firefighting exercise in temperate conditions. Furthermore, a second purpose of the study was to find out if the contribution of strength and endurance capacities to firefighting performance changes when the demands of the firefighting exercise change.Methods: Sixteen professional firefighters performed a maximum treadmill test, strength testing, a standard simulated firefighting exercise (SFE without heat and flashovers and a firefighting exercise with a simulation of the flashover phenomenon in a burning container (FOT. The treadmill testing was used to determine peak oxygen uptake (VO2peak, ventilatory threshold (VT1 and respiratory compensation point (RCP. Three intensity zones were identified according to heart rate (HR values corresponding to VT1 and RCP: zone 1–HR below VT1, zone 2-HR between VT1 and RCP, zone 3–HR above RCP. Firefighting performance was determined by a simple time-strain-air depletion model (TSA taking the sum of z-transformed parameters of time to finish the exercise, strain in terms of mean heart rate, and air depletion from the breathing apparatus. Correlations were then established between TSA based firefighting performance parameters and fitness variables representing strength and endurance.Results: HR was significantly lower during SFE (79.9 ± 6.9%HRmax compared to FOT (85.4 ± 5.2%HRmax. During SFE subjects spent 24.6 ± 30.2% of time in zone 1, 65.8 ± 28.1% in zone 2 and 9.7 ± 16.6% in zone 3. During FOT subjects spent 16.3 ± 12.8% in zone 1, 50.4 ± 13.2% in zone 2 and 33.3 ± 16.6% in zone 3. Out of all correlations, relative VO2peak showed the highest relation to mean HR during SFE (−0.593 as well as FOT (−0.693.Conclusions: Endurance in terms of

  17. A 414-year tree-ring-based April-July minimum temperature reconstruction and its implications for the extreme climate events, northeast China

    Science.gov (United States)

    Lyu, Shanna; Li, Zongshan; Zhang, Yuandong; Wang, Xiaochun

    2016-09-01

    A ring-width series was used as a proxy to reconstruct the past 414-year record of April-July minimum temperature at Laobai Mountain, northeast China. The chronology was built using standard tree-ring procedures for providing comparable information in this area while preserving low-frequency signals. By analyzing the relationship between the tree-ring chronology of Korean pine (Pinus koraiensis) and meteorological data, we found that the standard chronology was significantly correlated with the April-July minimum temperature (r = 0.757, p century were consistent with the Little Ice Age (LIA) in the Northern Hemisphere, and the rate of warming in the 19th century was significantly slower than that in the late 20th century. In addition, the reconstructed series was fairly consistent with the historical and natural disaster records of extreme climate events (e.g., cold damage and frost disaster) in this area. This temperature record provides new evidence of past climate variability, and can be used to predict the climate trend in the future in northeast China.

  18. Assessing the impacts of changing precipitation and temperature extremes on the current and future ecohydrology of grassland ecosystems

    Science.gov (United States)

    Brunsell, N. A.; Nippert, J. B.; Ocheltree, T.

    2012-12-01

    Extreme weather events have profound impacts on water and carbon cycling. However, events of similar magnitude may have very different impacts depending upon the timing of the event in the phenological cycle. We assess these impacts of extreme daily weather events including precipitation, maximum and minimum temperature using data collected from the Konza Prairie Long Term Ecological Research site in the central U.S. We utilize the long term weather and biomass collection data at the LTER site to examine the historical variability of extreme events and the impacts on annual carbon dynamics. Timescales of interactions between daily weather and fluxes are quantified through a multiscale information theoretic approach. In addition, we quantify the impacts of the timing and magnitude of extreme events through a Critical Climate Period (CCP) analysis. Results indicate a strong sensitivity to spring precipitation and summer temperature. Using six years of eddy covariance data, we can isolate more of the biophysical mechanisms governing the responses to extreme weather events. Of particular interest is the heat wave of July, 2011, where daily maximum temperatures were over 38 C for 24 consecutive days and resulted in drastically reduced above ground carbon allocation than in previous years. In addition, we employ the Agro-BGC model to assess the biophysical processes responsible for determining the response of water and carbon dynamics to extreme weather events. This is done by employing a stochastic weather generator with prescribed changes in annual precipitation and temperature conistent with GCM projections. Developing a more thorough understanding of extreme events and the differential responses due to the timing and magnitude of the events will potentially assist in the mitigation of future climate change.

  19. Automated cold temperature cycling improves in vitro platelet properties and in vivo recovery in a mouse model compared to continuous cold storage.

    Science.gov (United States)

    Skripchenko, Andrey; Gelderman, Monique P; Awatefe, Helen; Turgeon, Annette; Thompson-Montgomery, Dedeene; Cheng, Chunrong; Vostal, Jaroslav G; Wagner, Stephen J

    2016-01-01

    Platelets (PLTs) stored at cold temperatures (CTs) for prolonged time have dramatically reduced bacterial growth but poor survival when infused. A previous study demonstrated that human PLTs stored with manual cycling between 4 °C (12 hr) and 37 °C (30 min) and infused into severe combined immunodeficient (SCID) mice had survivals similar to or greater than those stored at room temperature (RT). In this study, the in vitro and in vivo properties of PLTs stored in an automated incubator programmed to cycle between 5 °C (11 hr) and 37 °C (1 hr) were evaluated. A Trima apheresis unit (n = 12) was aliquoted (60 mL) in CLX bags. One sample was stored with continuous agitation (RT), a second sample was stored at 4-6 °C without agitation (CT), and a third sample was placed in an automated temperature cycler with 5 minutes of agitation during the warm-up period (thermocycling [TC]). PLTs were assayed for several relevant quality variables. On Day 7, PLTs were infused into SCID mice and in vivo recovery was assessed at predetermined time points after transfusion. The glucose consumption rate, morphology score, hypotonic shock recovery level, and aggregation levels were increased and mitochondrial reactive oxygen species accumulations were decreased in TC-PLTs compared to those of CT-PLTs. The pH and Annexin V binding were comparable to those of RT-PLTs. All TC-PLTs had greater recovery than CT-PLTs and were comparable to RT-PLTs. PLTs stored under automated TC conditions have improved in vivo recovery and improved results for a number of in vitro measures compared to CT-PLTs. © 2015 AABB.

  20. Extreme climatic events: impacts of drought and high temperature on physiological processes in agronomically important plants

    Directory of Open Access Journals (Sweden)

    Urs eFeller

    2014-10-01

    Full Text Available Climate models predict more frequent and more severe extreme events (e.g. heat waves, extended drought periods, flooding in many regions for the next decades. The impact of adverse environmental conditions on crop plants is ecologically and economically relevant. This review is focused on drought and heat effects on physiological status and productivity of agronomically important plants. Stomatal opening represents an important regulatory mechanism during drought and heat stress since it influences simultaneously water loss via transpiration and CO2 diffusion into the leaf apoplast which further is utilized in photosynthesis. Along with the reversible short-term control of stomatal opening, stomata and leaf epidermis may produce waxy deposits and irreversibly down-regulate the stomatal conductance and non-stomatal transpiration. As a consequence photosynthesis will be negatively affected. Rubisco activase - a key enzyme in keeping the Calvin cycle functional – is heat-sensitive and may become a limiting factor at elevated temperature. The accumulated reactive oxygen species during stress represent an additional challenge under unfavorable conditions. Drought and heat cause accumulation of free amino acids which are partially converted into compatible solutes such as proline. This is accompanied by lower rates of both nitrate reduction and de novo amino acid biosynthesis. Protective proteins (e.g. dehydrins, chaperones, antioxidant enzymes or the key enzyme for proline biosynthesis play an important role in leaves and may be present at higher levels under water deprivation or high temperatures. On the whole plant level, effects on long-distance translocation of solutes via xylem and phloem and on leaf senescence (e.g. anticipated, accelerated or delayed senescence are important. The factors mentioned above are relevant for the overall performance of crops under drought and heat and must be considered for genotype selection and breeding programs.

  1. Choice of optimal working fluid for binary power plants at extremely low temperature brine

    Science.gov (United States)

    Tomarov, G. V.; Shipkov, A. A.; Sorokina, E. V.

    2016-12-01

    The geothermal energy development problems based on using binary power plants utilizing lowpotential geothermal resources are considered. It is shown that one of the possible ways of increasing the efficiency of heat utilization of geothermal brine in a wide temperature range is the use of multistage power systems with series-connected binary power plants based on incremental primary energy conversion. Some practically significant results of design-analytical investigations of physicochemical properties of various organic substances and their influence on the main parameters of the flowsheet and the technical and operational characteristics of heat-mechanical and heat-exchange equipment for binary power plant operating on extremely-low temperature geothermal brine (70°C) are presented. The calculation results of geothermal brine specific flow rate, capacity (net), and other operation characteristics of binary power plants with the capacity of 2.5 MW at using various organic substances are a practical interest. It is shown that the working fluid selection significantly influences on the parameters of the flowsheet and the operational characteristics of the binary power plant, and the problem of selection of working fluid is in the search for compromise based on the priorities in the field of efficiency, safety, and ecology criteria of a binary power plant. It is proposed in the investigations on the working fluid selection of the binary plant to use the plotting method of multiaxis complex diagrams of relative parameters and characteristic of binary power plants. Some examples of plotting and analyzing these diagrams intended to choose the working fluid provided that the efficiency of geothermal brine is taken as main priority.

  2. Extreme maximum temperature events and their relationships with large-scale modes: potential hazard on the Iberian Peninsula

    Science.gov (United States)

    Merino, Andrés; Martín, M. L.; Fernández-González, S.; Sánchez, J. L.; Valero, F.

    2017-07-01

    The aim of this paper is to analyze spatiotemporal distribution of maximum temperatures in the Iberian Peninsula (IP) by using various extreme maximum temperature indices. Thresholds for determining temperature extreme event (TEE) severity are defined using 99th percentiles of daily temperature time series for the period 1948 to 2009. The synoptic-scale fields of such events were analyzed in order to better understand the related atmospheric processes. The results indicate that the regions with a higher risk of maximum temperatures are located in the river valleys of southwest and northeast of the IP, while the Cantabrian coast and mountain ranges are characterized by lower risk. The TEEs were classified, by means of several synoptic fields (sea level pressure, temperature, and geopotential height at 850 and 500 hPa), in four clusters that largely explain their spatiotemporal distribution on the IP. The results of this study show that TEEs mainly occur associated with a ridge elongated from Subtropical areas. The relationships of TEEs with teleconnection patterns, such as the North Atlantic Oscillation (NAO), Western Mediterranean Oscillation (WeMO), and Mediterranean Oscillation (MO), showed that the interannual variability of extreme maximum temperatures is largely controlled by the dominant phase of WeMO in all seasons except wintertime where NAO is prevailing. Results related to MO pattern show less relevance in the maximum temperatures variability. The correct identification of synoptic patterns linked with the most extreme temperature event associated with each cluster will assist the prediction of events that can pose a natural hazard, thereby providing useful information for decision making and warning systems.

  3. Hinode/Extreme-Ultraviolet Imaging Spectrometer Observations of the Temperature Structure of the Quiet Corona

    CERN Document Server

    Brooks, David H; Williams, David R; Watanabe, Tetsuya

    2009-01-01

    We present a Differential Emission Measure (DEM) analysis of the quiet solar corona on disk using data obtained by the Extreme-ultraviolet Imaging Spectrometer (EIS) on Hinode. We show that the expected quiet Sun DEM distribution can be recovered from judiciously selected lines, and that their average intensities can be reproduced to within 30%. We present a subset of these selected lines spanning the temperature range log T = 5.6 to 6.4 K that can be used to derive the DEM distribution reliably, including a subset of Iron lines that can be used to derive the DEM distribution free of the possibility of uncertainties in the elemental abundances. The subset can be used without the need for extensive measurements and the observed intensities can be reproduced to within the estimated uncertainty in the pre-launch calibration of EIS. Furthermore, using this subset, we also demonstrate that the quiet coronal DEM distribution can be recovered on size scales down to the spatial resolution of the instrument (1" pixels...

  4. PRTs and Their Bonding for Long-Duration, Extreme-Temperature Environments

    Science.gov (United States)

    Ramesham, Rajeshuni; Cucullu, Gordon C., III; Mikhaylov, Rebecca L.

    2012-01-01

    Research was conducted on the qualification of Honeywell platinum resistance thermometer (PRT) bonding for use in the Mars Science Laboratory (MSL). This is the first time these sensors will be used for Mars-related projects. Different types of PRTs were employed for the Mars Exploration Rover (MER) project, and several reliability issues were experienced, even for a shortduration mission like MER compared to MSL. Therefore, the development of a qualification process for the Honeywell PRT bonding was needed for the MSL project. Reliability of the PRT sensors, and their bonding processes, is a key element to understand the health of the hardware during all stages of the project, and particularly during surface operations on Mars. Three extreme temperature summer season cycles and three winter season cycles (total: 1983 thermal cycles) were completed, and no Honeywell PRT failures associated with the bonding process were found. Seventy-eight PRTs were bonded onto six different substrate materials using four different adhesives during the thermal cycling, which included a planetary protection cycle to +125 C for two hours, three protoflight/qualification cycles (-135 to 70 C), 1,384 summer cycles (-105 to 40 C), and 599 winter cycles (-130 to 15 C). There were no observed changes in PRT resistances, bonding characteristics, or damage identified from the package evaluation as a result of the qualification tests.

  5. Low Temperature Preparation and Cold Manufacturing Techniques for Femoral Head of Al2O3 Ceramic

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The hip joint femoral head prosthesis was prepared using the Al2O3 material, which was synthesized by high purity alumina micro-powder and Mg- Zr- Y composite additives, the cold manufacturing techniques of lathe turning, grade polishing and the matching size correction of the sintered femoral head were studied. The results showed, after being pressed under 200 MPa cold isostatic pressure and being pre-sintered at 1 150 ℃, the biscuit' s strength can meet the demands of lathe turning; After being grade polished by SiC micro-powder and diamond abrading agent and being size corrected by special instruments, the femoral head prosthesis of Al2O3 ceramic has good surface degree of finish and articulates tightly with femoral handle.

  6. Anatomical Structure Comparison Between Leaves of Two Winter Wheat Cultivars with Different Cold/Freezing Tolerance Under Low Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    YU Jing; CANG Jing; ZHOU Zishan; LIU Lijie

    2011-01-01

    Winter wheat (Triticum aestivum) cultivars Dongnongdongmai 1 with strong cold/freezing tolerance and Jimai 22 with weak cold/freezing tolerance were used for investigating the difference of microstructure and ultrastructure between leaves of two cultivars under low temperature stress (5℃ and -15 ℃) using optical and electron microscope. The results showed that there was no obvious difference between leaves of Dongnongdongmai 1 and Jimai 22 in microstructure. However, the difference between those leaves was distinct in ultrastructure. The grana lamella and stroma lamella were stacked regularly and arranged parallelly along the long axis of chloroplasts in cv. Dongnongdongmai 1, while the arrangement directions of thylakoids in Jimai 22's leaves were so irregular as to form various angles with the long axis of chloroplasts. At -15℃, the mitochondrias were swelled to be round and the structure of cristaes became blurry in both cultivars' leaves, while some cristaes of Jimai 22 disappeared. These results would provide theoretical evidence for selecting cold/freezing tolerant winter wheat germplasm resources

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