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Sample records for ambient temperature secondary

  1. Advances in ambient temperature secondary lithium cells

    Science.gov (United States)

    Subbarao, S.; Shen, D. H.; Deligiannis, F.; Huang, C-K.; Halpert, G.

    1989-01-01

    The Jet Propulsion Laboratory is involved in a Research and Development program sponsored by NASA/OAST on the development of ambient temperature secondary lithium cells for future space applications. Some of the projected applications are planetary spacecraft, planetary rovers, and astronaut equipment. The main objective is to develop secondary lithium cells with greater than 100 Wh/kg specific energy while delivering 1000 cycles at 50 percent Depth of Discharge (DOD). To realize these ambitious goals, the work was initially focused on several important basic issues related to the cell chemistry, selection of cathode materials and electrolytes, and component development. The performance potential of Li-TiS2, Li-MoS3, Li-V6O13 and Li-NbSe3 electrochemical systems was examined. Among these four, the Li-TiS2 system was found to be the most promising system in terms of realizable specific energy and cycle life. Some of the major advancements made so far in the development of Li-TiS2 cells are in the areas of cathode processing technology, mixed solvent electrolytes, and cell assembly. Methods were developed for the fabrication of large size high performance TiS2 cathodes. Among the various electrolytes examined, 1.5M LiAsF6/EC + 2-MeTHF mixed solvent electrolyte was found to be more stable towards lithium. Experimental cells activated with this electrolyte exhibited more than 300 cycles at 100 percent Depth of Discharge. Work is in progress in other areas such as selection of lithium alloys as candidate anode materials, optimization of cell design, and development of 5 Ah cells. The advances made at the Jet Propulsion Laboratory on the development of secondary lithium cells are summarized.

  2. The cycle life chemistry of ambient-temperature secondary lithium cells

    Science.gov (United States)

    Somoano, R.; Carter, B. J.; Subba Rao, S.; Shen, D.; Yen, S. P. S.

    1985-01-01

    The Jet Propulsion Laboratory is involved in a NASA-sponsored research program to demonstrate the feasibility of ambient-temperature secondary lithium batteries for geosynchronous space applications. Encouraging cycle life has been demonstrated in sealed, cathode-limited laboratory cells. However, the cell capacity declines with cycle life. The results of recent studies of the lithium electrode passivation chemistry, and of conductive diluents for TiS2 cathodes and their possible contribution to capacity decline, are here presented. Technical issues associated with the unique operational requirements of a geosynchronous mission are also described.

  3. Ambient temperature influences tolerance to plant secondary compounds in a mammalian herbivore.

    Science.gov (United States)

    Kurnath, P; Merz, N D; Dearing, M D

    2016-01-13

    Growing evidence suggests that plant secondary compounds (PSCs) ingested by mammals become more toxic at elevated ambient temperatures, a phenomenon known as temperature-dependent toxicity. We investigated temperature-dependent toxicity in the desert woodrat (Neotoma lepida), a herbivorous rodent that naturally encounters PSCs in creosote bush (Larrea tridentata), which is a major component of its diet. First, we determined the maximum dose of creosote resin ingested by woodrats at warm (28-29°C) or cool (21-22°C) temperatures. Second, we controlled the daily dose of creosote resin ingested at warm, cool and room (25°C) temperatures, and measured persistence in feeding trials. At the warm temperature, woodrats ingested significantly less creosote resin; their maximum dose was two-thirds that of animals at the cool temperature. Moreover, woodrats at warm and room temperatures could not persist on the same dose of creosote resin as woodrats at the cool temperature. Our findings demonstrate that warmer temperatures reduce PSC intake and tolerance in herbivorous rodents, highlighting the potentially adverse consequences of temperature-dependent toxicity. These results will advance the field of herbivore ecology and may hone predictions of mammalian responses to climate change. © 2016 The Author(s).

  4. The relationship between body and ambient temperature and corneal temperature

    DEFF Research Database (Denmark)

    Kessel, Line; Johnson, Leif; Arvidsson, Henrik Sven

    2010-01-01

    Exposure to elevated ambient temperatures has been mentioned as a risk factor for common eye diseases, primarily presbyopia and cataract. The aim of the present study was to examine the relationship among ambient, cornea, and body core temperature.......Exposure to elevated ambient temperatures has been mentioned as a risk factor for common eye diseases, primarily presbyopia and cataract. The aim of the present study was to examine the relationship among ambient, cornea, and body core temperature....

  5. Effect of ambient pressure on Leidenfrost temperature.

    Science.gov (United States)

    Orejon, Daniel; Sefiane, Khellil; Takata, Yasuyuki

    2014-11-01

    The accurate prediction and control of the interaction of liquids with hot surfaces is paramount in numerous areas, including cooling applications. We present results illustrating the effect of ambient pressure on the temperature required for a droplet to levitate over a hot surface, i.e., the Leidenfrost temperature. In the present study the dependence of wetting and levitating temperatures on ambient pressure in a range of subatmospheric pressures is reported. Experimental data indicate that the Leidenfrost temperature decreases with decreasing pressure at subatmospheric pressures. A physical approach for the dependence of Leidenfrost temperature on ambient pressure, based on an analogy with saturation pressure dependence, is proposed. Furthermore, previous literature data for pressures above atmospheric are also included in the analysis to support and validate the proposed approach. In addition, the effect of substrate material, substrate roughness, and type of fluid on the Leidenfrost temperature is discussed.

  6. Secondary organic aerosols: Formation potential and ambient data

    DEFF Research Database (Denmark)

    Barthelmie, R.J.; Pryor, S.C.

    1997-01-01

    Organic aerosols comprise a significant fraction of the total atmospheric particle loading and are associated with radiative forcing and health impacts. Ambient organic aerosol concentrations contain both a primary and secondary component. Herein, fractional aerosol coefficients (FAC) are used...... in conjunction with measurements of volatile organic compounds (VOC) to predict the formation potential of secondary organic aerosols (SOA) in the Lower Fraser Valley (LEV) of British Columbia. The predicted concentrations of SOA show reasonable accord with ambient aerosol measurements and indicate considerable...

  7. Ambient temperature modelling with soft computing techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bertini, Ilaria; Ceravolo, Francesco; Citterio, Marco; Di Pietra, Biagio; Margiotta, Francesca; Pizzuti, Stefano; Puglisi, Giovanni [Energy, New Technology and Environment Agency (ENEA), Via Anguillarese 301, 00123 Rome (Italy); De Felice, Matteo [Energy, New Technology and Environment Agency (ENEA), Via Anguillarese 301, 00123 Rome (Italy); University of Rome ' ' Roma 3' ' , Dipartimento di Informatica e Automazione (DIA), Via della Vasca Navale 79, 00146 Rome (Italy)

    2010-07-15

    This paper proposes a hybrid approach based on soft computing techniques in order to estimate monthly and daily ambient temperature. Indeed, we combine the back-propagation (BP) algorithm and the simple Genetic Algorithm (GA) in order to effectively train artificial neural networks (ANN) in such a way that the BP algorithm initialises a few individuals of the GA's population. Experiments concerned monthly temperature estimation of unknown places and daily temperature estimation for thermal load computation. Results have shown remarkable improvements in accuracy compared to traditional methods. (author)

  8. Significance and influence of the ambient temperature as a rate ...

    Indian Academy of Sciences (India)

    Unknown

    , undoubtedly is dependent even on the level of the ambient temperature. Therefore, the ambient temperature seems to be an important factor of the corrosion rate and the durability of the reinforced concrete structures in aggressive ...

  9. Chemical destruction of PCBs at ambient temperatures

    International Nuclear Information System (INIS)

    Dole, L.R.

    1991-01-01

    This paper reports the development and testing of a one-step process that destroys PCBs at ambient temperatures. QUALTEC's process works on contaminated auto fluffs containing 50-200 ppm PCBs. These PCBs come from capacitors, transformers, hydraulic fluids, adhesives and plasticizers from cars and appliances. This low-temperature destruction process reduces the PCB concentration by more that 40%. The results were verified in two independent laboratories. These laboratories showed a 43% destruction of PCBs at a 95% confidence level. The laboratory results also showed that the reactions released no VOCs. Also, no harmful organic reaction byproducts were found by U.S. EPA SW-846 Method 8072 of analysis. The treated waste was fixed by adding binders. After a second fixation step, the final waste form passed the U.S. EPA's TCLP requirements and was not characteristically hazardous. The fixed product is acceptable at an unlined California Class III municipal landfill. The concentration of PCBs in the final waste form was less than 25 ppm at a 99% confidence level

  10. Fundamental study of a one-step ambient temperature ferrite ...

    African Journals Online (AJOL)

    Fundamental study of a one-step ambient temperature ferrite process for treatment of acid mine drainage waters: rapid communication. ... The approach involves the controlled oxidation of ferrous-containing AMD water at ambient temperatures in the presence of magnetite seed. The resulting oxidation product is the ferrite ...

  11. Effect of ambient temperature on female endurance performance.

    Science.gov (United States)

    Renberg, Julie; Sandsund, Mariann; Wiggen, Øystein Nordrum; Reinertsen, Randi Eidsmo

    2014-10-01

    Ambient temperature can affect physical performance, and an ambient temperature range of -4 °C to 11 °C is optimal for endurance performance in male athletes. The few similar studies of female athletes appear to have found differences in response to cold between the genders. This study investigated whether ambient temperature affects female endurance performance. Nine athletes performed six tests while running on a treadmill in a climatic chamber at different ambient temperatures: 20, 10, 1, -4, -9 and -14 °C and a wind speed of 5 m s(-1). The exercise protocol consisted of a 10-min warm-up, followed by four 5-min intervals at increasing intensities at 76%, 81%, 85%, and 89% of maximal oxygen consumption. This was followed by an incremental test to exhaustion. Although peak heart rate, body mass loss, and blood lactate concentration after the incremental test to exhaustion increased as the ambient temperature rose, no changes in time to exhaustion, running economy, running speed at lactate threshold or maximal oxygen consumption were found between the different ambient temperature conditions. Endurance performance during one hour of incremental exercise was not affected by ambient temperature in female endurance athletes. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. The effect of ambient temperature and solar panel's surface ...

    African Journals Online (AJOL)

    The absorbance layer employed in the production of the solar panel is assumed to be responsible for the high temperatures retained on the solar panel's surface when compared with the ambient temperatures. The results show that the lower the temperature difference between solar panel's surface temperature and ...

  13. Patterns of Body Temperature During Feeding in Rats Under Varying Ambient Temperatures

    NARCIS (Netherlands)

    de Vries, Jan; Strubbe, Jan H.; Wildering, Wic C.; Gorter, Jan A.; Prins, Ab J.A.

    Relationships between feeding and body temperature of rats were investigated at three ambient temperatures during the whole light/dark cycle. Basal liver temperature was negatively correlated with ambient temperature. Only at 29-degrees-C liver temperature indicated activation of autonomic and

  14. Significance and influence of the ambient temperature as a rate ...

    Indian Academy of Sciences (India)

    Unknown

    ). The case of an open system of the dependence ambient temperature – corrosion rate shown in figure 5 is identical to that found in our study. It confirms that the corroding system consisting of embedded steel – porous embedding.

  15. Passive radiative cooling below ambient air temperature under direct sunlight.

    Science.gov (United States)

    Raman, Aaswath P; Anoma, Marc Abou; Zhu, Linxiao; Rephaeli, Eden; Fan, Shanhui

    2014-11-27

    Cooling is a significant end-use of energy globally and a major driver of peak electricity demand. Air conditioning, for example, accounts for nearly fifteen per cent of the primary energy used by buildings in the United States. A passive cooling strategy that cools without any electricity input could therefore have a significant impact on global energy consumption. To achieve cooling one needs to be able to reach and maintain a temperature below that of the ambient air. At night, passive cooling below ambient air temperature has been demonstrated using a technique known as radiative cooling, in which a device exposed to the sky is used to radiate heat to outer space through a transparency window in the atmosphere between 8 and 13 micrometres. Peak cooling demand, however, occurs during the daytime. Daytime radiative cooling to a temperature below ambient of a surface under direct sunlight has not been achieved because sky access during the day results in heating of the radiative cooler by the Sun. Here, we experimentally demonstrate radiative cooling to nearly 5 degrees Celsius below the ambient air temperature under direct sunlight. Using a thermal photonic approach, we introduce an integrated photonic solar reflector and thermal emitter consisting of seven layers of HfO2 and SiO2 that reflects 97 per cent of incident sunlight while emitting strongly and selectively in the atmospheric transparency window. When exposed to direct sunlight exceeding 850 watts per square metre on a rooftop, the photonic radiative cooler cools to 4.9 degrees Celsius below ambient air temperature, and has a cooling power of 40.1 watts per square metre at ambient air temperature. These results demonstrate that a tailored, photonic approach can fundamentally enable new technological possibilities for energy efficiency. Further, the cold darkness of the Universe can be used as a renewable thermodynamic resource, even during the hottest hours of the day.

  16. The Association of Ambient Temperature and Violent Crime.

    Science.gov (United States)

    Tiihonen, Jari; Halonen, Pirjo; Tiihonen, Laura; Kautiainen, Hannu; Storvik, Markus; Callaway, James

    2017-07-28

    It is controversial if global warming will result into increased crime and conflict rate, and no causal neurobiological mechanisms have been proposed for the putative association between ambient temperature and aggressive behavior. This study shows that during 1996-2013, ambient temperature explained 10% of variance in the violent crime rate in Finland, corresponding to a 1.7% increase/degree centigrade. Ambient temperature also correlated with a one month delay in circannual changes in peripheral serotonin transporter density among both offenders and healthy control subjects, which itself correlated strongly with the monthly violent crime rate. This suggests that rise in temperature modulates serotonergic transmission which may increase impulsivity and general human activity level, resulting into increase in social interaction and risk of violent incidents. Together, these results suggest that the effect of ambient temperature on occurrence of violent crime is partly mediated through the serotonergic system, and that a 2 °C increase in average temperatures would increase violent crime rates by more than 3% in non-tropical and non-subtropical areas, if other contributing factors remained constant.

  17. Effect of Gas Turbine Exhaust Temperature, Stack Temperature and Ambient Temperature on Overall Efficiency of Combine Cycle Power Plant

    OpenAIRE

    M.N.Khan; K.P.Tyagi

    2010-01-01

    The gas turbine exhaust temperature, stack temperature and ambient temperature play a very important role during the predication of the performance of combine cycle power plant. This paper covers parametric analysis of effects of gas turbine exhaust temperature, stack temperature and ambient temperature on the overall efficiency of combine cycle power plant keeping the gas turbine efficiency as well as steam turbine efficiency constant. The results shows that out of three variables i.e. turbi...

  18. Storage beyond Three Hours at Ambient Temperature Alters the ...

    African Journals Online (AJOL)

    The effect of storage on stability of human breast milk was investigated in 30 lactating mothers. Samples stored for 3, 6 and 24 hours at ambient temperature of 302K (29°) were analysed for protein, lactose, pH, and microbial content. There were significant (p < 0.01) decreases in protein, lactose and pH upon storage for 6 ...

  19. A seeded ambient temperature ferrite process for treatment of AMD ...

    African Journals Online (AJOL)

    A seeded ambient temperature ferrite process for treatment of AMD waters: magnetite formation in the presence and absence of calcium ions under steady state operation. ... promising for AMD treatment. Keywords: Ferrite process, Magnetite seed, Calcium interference, Acid mine drainage (WaterSA: 2003 29(2): 117-124) ...

  20. Low Ambient Temperature and Intracerebral Hemorrhage: The INTERACT2 Study.

    Directory of Open Access Journals (Sweden)

    Danni Zheng

    Full Text Available Rates of acute intracerebral hemorrhage (ICH increase in winter months but the magnitude of risk is unknown. We aimed to quantify the association of ambient temperature with the risk of ICH in the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trial (INTERACT2 participants on an hourly timescale.INTERACT2 was an international, open, blinded endpoint, randomized controlled trial of patients with spontaneous ICH (<6h of onset and elevated systolic blood pressure (SBP, 150-220 mmHg assigned to intensive (target SBP <140 mmHg or guideline-recommended (SBP <180 mmHg BP treatment. We linked individual level hourly temperature to baseline data of 1997 participants, and performed case-crossover analyses using a distributed lag non-linear model with 24h lag period to assess the association of ambient temperature and risk of ICH. Results were presented as overall cumulative odds ratios (ORs and 95% CI.Low ambient temperature (≤10°C was associated with increased risks of ICH: overall cumulative OR was 1.37 (0.99-1.91 for 10°C, 1.92 (1.31-2.81 for 0°C, 3.13 (1.89-5.19 for -10°C, and 5.76 (2.30-14.42 for -20°C, as compared with a reference temperature of 20°C.There was no clear relation of low temperature beyond three hours after exposure. Results were consistent in sensitivity analyses.Exposure to low ambient temperature within several hours increases the risk of ICH.ClinicalTrials.gov NCT00716079.

  1. Effect of ambient temperature on caffeine ergogenicity during endurance exercise.

    Science.gov (United States)

    Ganio, Matthew S; Johnson, Evan C; Klau, Jennifer F; Anderson, Jeffrey M; Casa, Douglas J; Maresh, Carl M; Volek, Jeff S; Armstrong, Lawrence E

    2011-06-01

    It is well established that caffeine ingestion during exercise enhances endurance performance. Conversely, the physiological and psychological strain that accompanies increased ambient temperature decreases endurance performance. Little is known about the interaction between environmental temperature and the effects of caffeine on performance. The purpose of this study was to compare the effects of ambient temperature (12 and 33°C) on caffeine ergogenicity during endurance cycling exercise. Eleven male cyclists (mean ± SD; age, 25 ± 6 years; [Formula: see text] 58.7 ± 2.9 ml kg(-1) min(-1)) completed four exercise trials in a randomized, double blind experimental design. After cycling continuously for 90 min (average 65 ± 7% [Formula: see text]) in either a warm (33 ± 1°C, 41 ± 5%rh) or cool (12 ± 1°C, 60 ± 7%rh) environment, subjects completed a 15-min performance trial (PT; based on total work accumulated). Subjects ingested 3 mg kg(-1) of encapsulated caffeine (CAF) or placebo (PLA) 60 min prior to and after 45 min of exercise. Throughout exercise, subjects ingested water so that at the end of exercise, independent of ambient temperature, their body mass was reduced 0.55 ± 0.67%. Two-way (temperature × treatment) repeated-measures ANOVA were conducted with alpha set at 0.05. Total work (kJ) during the PT was greater in 12°C than 33°C [P performance versus PLA independent of temperature (P = 0.006, η(2) = 0.542 CI: 3.60-16.86). However, performance differences with CAF were not dependent on ambient temperature (i.e., non-significant interaction; P = 0.662). CAF versus PLA in 12 and 33°C resulted in few differences in other physiological variables. However, during exercise, rectal temperature (T (re)) increased in the warm environment (peak T (re); 33°C, 39.40 ± 0.45; 12°C, 38.79 ± 0.42°C; P 0.05). Increased ambient temperature had a detrimental effect on cycling performance in both the CAF and PLA conditions. CAF improved performance

  2. The relationship of lung function with ambient temperature.

    Science.gov (United States)

    Collaco, Joseph M; Appel, Lawrence J; McGready, John; Cutting, Garry R

    2018-01-01

    Lung function is complex trait with both genetic and environmental factors contributing to variation. It is unknown how geographic factors such as climate affect population respiratory health. To determine whether ambient air temperature is associated with lung function (FEV1) in the general population. Associations between spirometry data from two National Health and Nutrition Examination Survey (NHANES) periods representative of the U.S. non-institutionalized population and mean annual ambient temperature were assessed using survey-weighted multivariate regression. The NHANES III (1988-94) cohort included 14,088 individuals (55.6% female) and the NHANES 2007-12 cohort included 14,036 individuals (52.3% female), with mean ages of 37.4±23.4 and 34.4±21.8 years old and FEV1 percent predicted values of 99.8±15.8% and 99.2±14.5%, respectively. After adjustment for confounders, warmer ambient temperatures were associated with lower lung function in both cohorts (NHANES III p = 0.020; NHANES 2007-2012 p = 0.014). The effect was similar in both cohorts with a 0.71% and 0.59% predicted FEV1 decrease for every 10°F increase in mean temperature in the NHANES III and NHANES 2007-2012 cohorts, respectively. This corresponds to ~2 percent predicted difference in FEV1 between the warmest and coldest regions in the continental United States. In the general U.S. population, residing in regions with warmer ambient air temperatures was associated with lower lung function with an effect size similar to that of traffic pollution. Rising temperatures associated with climate change could have effects on pulmonary function in the general population.

  3. The relationship of lung function with ambient temperature.

    Directory of Open Access Journals (Sweden)

    Joseph M Collaco

    Full Text Available Lung function is complex trait with both genetic and environmental factors contributing to variation. It is unknown how geographic factors such as climate affect population respiratory health.To determine whether ambient air temperature is associated with lung function (FEV1 in the general population.Associations between spirometry data from two National Health and Nutrition Examination Survey (NHANES periods representative of the U.S. non-institutionalized population and mean annual ambient temperature were assessed using survey-weighted multivariate regression.The NHANES III (1988-94 cohort included 14,088 individuals (55.6% female and the NHANES 2007-12 cohort included 14,036 individuals (52.3% female, with mean ages of 37.4±23.4 and 34.4±21.8 years old and FEV1 percent predicted values of 99.8±15.8% and 99.2±14.5%, respectively.After adjustment for confounders, warmer ambient temperatures were associated with lower lung function in both cohorts (NHANES III p = 0.020; NHANES 2007-2012 p = 0.014. The effect was similar in both cohorts with a 0.71% and 0.59% predicted FEV1 decrease for every 10°F increase in mean temperature in the NHANES III and NHANES 2007-2012 cohorts, respectively. This corresponds to ~2 percent predicted difference in FEV1 between the warmest and coldest regions in the continental United States.In the general U.S. population, residing in regions with warmer ambient air temperatures was associated with lower lung function with an effect size similar to that of traffic pollution. Rising temperatures associated with climate change could have effects on pulmonary function in the general population.

  4. Experiment of ambient temperature distribution in ICF driver's target building

    International Nuclear Information System (INIS)

    Zhou Yi; He Jie; Yang Shujuan; Zhang Junwei; Zhou Hai; Feng Bin; Xie Na; Lin Donghui

    2009-01-01

    An experiment is designed to explore the ambient temperature distribution in an ICF driver's target building, Multi-channel PC-2WS temperature monitoring recorders and PTWD-2A precision temperature sensors are used to measure temperatures on the three vertical cross-sections in the building, and the collected data have been handled by MATLAB. The experiment and analysis show that the design of the heating ventilation and air conditioning (HVAC) system can maintain the temperature stability throughout the building. However, because of the impact of heat in the target chamber, larger local environmental temperature gradients appear near the marshalling yard, the staff region on the middle floor, and equipments on the lower floor which needs to be controlled. (authors)

  5. 76 FR 59599 - Extension of Comment Period for Secondary National Ambient Air Quality Standards for Oxides of...

    Science.gov (United States)

    2011-09-27

    ... Extension of Comment Period for Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and... National Ambient Air Quality Standards for Oxides of Nitrogen and Sulfur to October 10, 2011. DATES: The... CONTACT: Questions concerning the ``Secondary National Ambient Air Quality Standards for Oxides of...

  6. The ADAM and EVE project: Heat transfer at ambient temperature

    International Nuclear Information System (INIS)

    Boltendahl, U.; Harth, R.

    1980-01-01

    In the nuclear research plant at Juelich a new heating system is at present being developed as part of the Nuclear Long-distance Heating Project. Helium is heated up in a high-temperature reactor. The heat chemically converts a gas mixture in a reformer plant (EVE). The gases 'charged' with energy can be transported through tubes over any distance required at ambient temperatures. In a methanisation plant (ADAM) the gases react with one another, releasing the energy in the form of heat which can be used for heating air or water. (orig.) [de

  7. Microbial community analysis of ambient temperature anaerobic digesters

    Energy Technology Data Exchange (ETDEWEB)

    Ciotola, R. [Ohio State Univ., Columbus, OH (United States). Dept. of Food, Agriculture and Biological Engineering

    2010-07-01

    This paper reported on a study in which designs for Chinese and Indian fixed-dome anaerobic digesters were modified in an effort to produce smaller and more affordable digesters. While these types of systems are common in tropical regions of developing countries, they have not been used in colder climates because of the low biogas yield during the winter months. Although there is evidence that sufficient biogas production can be maintained in colder temperatures through design and operational changes, there is a lack of knowledge about the seasonal changes in the composition of the microbial communities in ambient temperature digesters. More knowledge is needed to design and operate systems for maximum biogas yield in temperate climates. The purpose of this study was to cultivate a microbial community that maximizes biogas production at psychrophilic temperatures. The study was conducted on a 300 gallon experimental anaerobic digester on the campus of Ohio State University. Culture-independent methods were used on weekly samples collected from the digester in order to examine microbial community response to changes in ambient temperature. Microbial community profiles were established using universal bacterial and archaeal primers that targeted the 16S rRNA gene. In addition to the methanogenic archaea, this analysis also targeted some of the other numerically and functionally important microbial taxa in anaerobic digesters, such as hydrolytic, fermentative, acetogenic and sulfate reducing bacteria. According to preliminary results, the composition of the microbial community shifts with changes in seasonal temperature.

  8. Photoelectron Spectroscopy under Ambient Pressure and Temperature Conditions

    Energy Technology Data Exchange (ETDEWEB)

    Ogletree, D. Frank; Bluhm, Hendrik; Hebenstreit, Eleonore B.; Salmeron, Miquel

    2009-02-27

    We describe the development and applications of novel instrumentation for photoemission spectroscopy of solid or liquid surfaces in the presence of gases under ambient conditions or pressure and temperature. The new instrument overcomes the strong scattering of electrons in gases by the use of an aperture close to the surface followed by a differentially-pumped electrostatic lens system. In addition to the scattering problem, experiments in the presence of condensed water or other liquids require the development of special sample holders to provide localized cooling. We discuss the first two generations of Ambient Pressure PhotoEmission Spectroscopy (APPES) instruments developed at synchrotron light sources (ALS in Berkeley and BESSY in Berlin), with special focus on the Berkeley instruments. Applications to environmental science and catalytic chemical research are illustrated in two examples.

  9. Investigation of ambient temperature on the performance of GE-F5 gas turbine

    International Nuclear Information System (INIS)

    Ghazikhani, M.; Taffazoli, D.; Manshori, N.

    2002-01-01

    The role of ambient temperature in determining the performance of GE-F5 gas turbine is analysed by investigating the Shirvan gas turbine power plant 10 MW , 15 MW and 20 MW power output. These parameters have been brought as a function of ambient temperature. The results show when ambient temperature increases 1 deg C, The compressor pressure decreases about 20 k Pa, compressor outlet temperature increases about 1.13 deg C and exhaust temperature increases about 2.5 deg C. It is revealed that variations are due to decreasing the efficiency of compressor and less due to mass flow rate of air reduction as ambient temperature increases at constant power output. The results shows cycle efficiency reduces 3% with increasing 50 of ambient temperature, also the m increases as ambient temperature increase for constant turbine work. These are also because of reducing the compressor efficiency as ambient temperature increases

  10. 40 CFR Appendix P to Part 50 - Interpretation of the Primary and Secondary National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-07-01

    ... the data handling procedures for the reported data). 2.3Comparisons with the Primary and Secondary... Secondary National Ambient Air Quality Standards for Ozone P Appendix P to Part 50 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS NATIONAL PRIMARY AND SECONDARY AMBIENT AIR QUALITY...

  11. Ambient temperature influences the neural benefits of exercise.

    Science.gov (United States)

    Maynard, Mark E; Chung, Chasity; Comer, Ashley; Nelson, Katharine; Tran, Jamie; Werries, Nadja; Barton, Emily A; Spinetta, Michael; Leasure, J Leigh

    2016-02-15

    Many of the neural benefits of exercise require weeks to manifest. It would be useful to accelerate onset of exercise-driven plastic changes, such as increased hippocampal neurogenesis. Exercise represents a significant challenge to the brain because it produces heat, but brain temperature does not rise during exercise in the cold. This study tested the hypothesis that exercise in cold ambient temperature would stimulate hippocampal neurogenesis more than exercise in room or hot conditions. Adult female rats had exercise access 2h per day for 5 days at either room (20 °C), cold (4.5 °C) or hot (37.5 °C) temperature. To label dividing hippocampal precursor cells, animals received daily injections of BrdU. Brains were immunohistochemically processed for dividing cells (Ki67+), surviving cells (BrdU+) and new neurons (doublecortin, DCX) in the hippocampal dentate gyrus. Animals exercising at room temperature ran significantly farther than animals exercising in cold or hot conditions (room 1490 ± 400 m; cold 440 ± 102 m; hot 291 ± 56 m). We therefore analyzed the number of Ki67+, BrdU+ and DCX+ cells normalized for shortest distance run. Contrary to our hypothesis, exercise in either cold or hot conditions generated significantly more Ki67+, BrdU+ and DCX+ cells compared to exercise at room temperature. Thus, a limited amount of running in either cold or hot ambient conditions generates more new cells than a much greater distance run at room temperature. Taken together, our results suggest a simple means by which to augment exercise effects, yet minimize exercise time. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Thermal modelling of PV module performance under high ambient temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Diarra, D.C.; Harrison, S.J. [Queen' s Univ., Kingston, ON (Canada). Dept. of Mechanical and Materials Engineering Solar Calorimetry Lab; Akuffo, F.O. [Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana). Dept. of Mechanical Engineering

    2005-07-01

    When predicting the performance of photovoltaic (PV) generators, the actual performance is typically lower than test results conducted under standard test conditions because the radiant energy absorbed in the module under normal operation raises the temperature of the cell and other multilayer components. The increase in temperature translates to a lower conversion efficiency of the solar cells. In order to address these discrepancies, a thermal model of a characteristic PV module was developed to assess and predict its performance under real field-conditions. The PV module consisted of monocrystalline silicon cells in EVA between a glass cover and a tedlar backing sheet. The EES program was used to compute the equilibrium temperature profile in the PV module. It was shown that heat is dissipated towards the bottom and the top of the module, and that its temperature can be much higher than the ambient temperature. Modelling results indicate that 70-75 per cent of the absorbed solar radiation is dissipated from the solar cells as heat, while 4.7 per cent of the solar energy is absorbed in the glass cover and the EVA. It was also shown that the operating temperature of the PV module decreases with increased wind speed. 2 refs.

  13. Environmental embrittlement of ordered intermetallics at ambient temperatures

    International Nuclear Information System (INIS)

    Takasugi, Takayuki

    1993-01-01

    It is demonstrated that the environmental embrittlement of ordered intermetallics, which is caused by hydrogen released from moisture in air or hydrogen gas in environment at ambient temperatures, takes place in various kinds of crystal structures, alloys and microstructures. First, the phenomenology of the environmental embrittlement, i.e. atmosphere, temperature and strain rate dependencies, as well as alloying, doping and microstructural effects, is presented in terms of mechanical properties, fractography and microstructural features. Next, possible mechanisms of embrittlement involving the kinetics (i.e. decomposition, migration and condensation of hydrogen) and the bond breaking are discussed. Finally, some evidence indicating suppression of the embrittlement through selection of deformation condition, alloying and microstructural modification is presented. 52 refs., 11 figs., 2 tabs

  14. Association of elevated ambient temperature with death from cocaine overdose.

    Science.gov (United States)

    Auger, Nathalie; Bilodeau-Bertrand, Marianne; Labesse, Maud Emmanuelle; Kosatsky, Tom

    2017-09-01

    Ecologic data suggest that elevated outdoor temperature is correlated with mortality rates from cocaine overdose. Using non-aggregated death records, we studied the association of hot temperatures with risk of death from cocaine overdose. We carried out a case-crossover study of all deaths from cocaine or other drug overdose between the months of May and September, from 2000 through 2013 in Quebec, Canada. We used conditional logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for the association between maximum outdoor temperature and death from cocaine or other drug overdose. The main outcome measure was death from cocaine overdose as a function of maximum temperature the day of death and the days immediately preceding death. There were 316 deaths from cocaine overdose and 446 from other drug overdoses during the study. Elevated temperature the preceding week was associated with the likelihood of death from cocaine but not other drug overdose. Compared with 20°C, a maximum weekly temperature of 30°C was associated with an OR of 2.07 for death from cocaine overdose (95% CI 1.15-3.73), but an OR of 1.03 for other drug overdoses (95% CI 0.60-1.75). Associations for cocaine overdose were present with maximum daily temperature the day of and each of the three days preceding death. Elevated ambient temperature is associated with the risk of death from cocaine overdose. Public health practitioners and drug users should be aware of the added risk of mortality when cocaine is used during hot days. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Evaporation kinetics and phase of laboratory and ambient secondary organic aerosol

    Science.gov (United States)

    Vaden, Timothy D.; Imre, Dan; Beránek, Josef; Shrivastava, Manish; Zelenyuk, Alla

    2011-01-01

    Field measurements of secondary organic aerosol (SOA) find significantly higher mass loads than predicted by models, sparking intense effort focused on finding additional SOA sources but leaving the fundamental assumptions used by models unchallenged. Current air-quality models use absorptive partitioning theory assuming SOA particles are liquid droplets, forming instantaneous reversible equilibrium with gas phase. Further, they ignore the effects of adsorption of spectator organic species during SOA formation on SOA properties and fate. Using accurate and highly sensitive experimental approach for studying evaporation kinetics of size-selected single SOA particles, we characterized room-temperature evaporation kinetics of laboratory-generated α-pinene SOA and ambient atmospheric SOA. We found that even when gas phase organics are removed, it takes ∼24 h for pure α-pinene SOA particles to evaporate 75% of their mass, which is in sharp contrast to the ∼10 min time scale predicted by current kinetic models. Adsorption of “spectator” organic vapors during SOA formation, and aging of these coated SOA particles, dramatically reduced the evaporation rate, and in some cases nearly stopped it. Ambient SOA was found to exhibit evaporation behavior very similar to that of laboratory-generated coated and aged SOA. For all cases studied in this work, SOA evaporation behavior is nearly size-independent and does not follow the evaporation kinetics of liquid droplets, in sharp contrast with model assumptions. The findings about SOA phase, evaporation rates, and the importance of spectator gases and aging all indicate that there is need to reformulate the way SOA formation and evaporation are treated by models. PMID:21262848

  16. Ambient-temperature diffusion and gettering of Pt atoms in GaN with surface defect region under 60Co gamma or MeV electron irradiation

    Science.gov (United States)

    Hou, Ruixiang; Li, Lei; Fang, Xin; Xie, Ziang; Li, Shuti; Song, Weidong; Huang, Rong; Zhang, Jicai; Huang, Zengli; Li, Qiangjie; Xu, Wanjing; Fu, Engang; Qin, G. G.

    2018-01-01

    Generally, the diffusion and gettering of impurities in GaN needs high temperature. Calculated with the ambient-temperature extrapolation value of the high temperature diffusivity of Pt atoms in GaN reported in literature, the time required for Pt atoms diffusing 1 nm in GaN at ambient temperature is about 19 years. Therefore, the ambient-temperature diffusion and gettering of Pt atoms in GaN can hardly be observed. In this work, the ambient-temperature diffusion and gettering of Pt atoms in GaN is reported for the first time. It is demonstrated by use of secondary ion mass spectroscopy that in the condition of introducing a defect region on the GaN film surface by plasma, and subsequently, irradiated by 60Co gamma-ray or 3 MeV electrons, the ambient-temperature diffusion and gettering of Pt atoms in GaN can be detected. It is more obvious with larger irradiation dose and higher plasma power. With a similar surface defect region, the ambient-temperature diffusion and gettering of Pt atoms in GaN stimulated by 3 MeV electron irradiation is more marked than that stimulated by gamma irradiation. The physical mechanism of ambient-temperature diffusion and gettering of Pt atoms in a GaN film with a surface defect region stimulated by gamma or MeV electron irradiation is discussed.

  17. Etanercept (Enbrel® alternative storage at ambient temperature

    Directory of Open Access Journals (Sweden)

    Shannon E

    2017-07-01

    Full Text Available Edel Shannon,1 Joanne Daffy,2 Heather Jones,3 Andrea Paulson,4 Steven M Vicik5 1Global Chemistry, Manufacturing, and Controls Regulatory, 2Contract Operations Quality Assurance, Pfizer Ireland Pharmaceuticals, Clondalkin, Dublin, Ireland; 3Medical Affairs, Pfizer, Collegeville, PA, USA; 4Pharmaceutical Research and Development, 5Global Supply Product Portfolio Management, Pfizer Biotech, Andover, MA, USA Background: Biologic disease-modifying antirheumatic drugs, including tumor necrosis factor inhibitors such as etanercept (Enbrel®, have improved outcomes for patients with rheumatic and other inflammatory diseases, with sustained remission being the optimal goal for patients with rheumatoid arthritis. Flexible and convenient treatment options, compatible with modern lifestyle, are important in helping patients maintain treatment and manage their disease. Etanercept drug product (DP is available in lyophilized powder (Lyo for solution injection, prefilled syringe, and prefilled pen presentations and is typically stored under refrigerated conditions. We aimed to generate a comprehensive analytical data package from stability testing of key quality attributes, consistent with regulatory requirements, to determine whether the product profile of etanercept is maintained at ambient temperature. Methods: Test methods assessing key attributes of purity, quality, potency, and safety were performed over time, following storage of etanercept DP presentations under a range of conditions. Results: Results and statistical analysis from stability testing (based on size exclusion high-performance liquid chromatography, hydrophobic interaction chromatography, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis Coomassie across all etanercept presentations (10 and 25 mg/vial Lyo DP; 25 and 50 mg prefilled syringe DP; 50 mg prefilled pen DP showed key stability-indicating parameters were within acceptable limits through the alternative storage

  18. Grey water treatment in UASB reactor at ambient temperature.

    Science.gov (United States)

    Elmitwalli, T A; Shalabi, M; Wendland, C; Otterpohl, R

    2007-01-01

    In this paper, the feasibility of grey water treatment in a UASB reactor was investigated. The batch recirculation experiments showed that a maximum total-COD removal of 79% can be obtained in grey-water treatment in the UASB reactor. The continuous operational results of a UASB reactor treating grey water at different hydraulic retention time (HRT) of 20, 12 and 8 hours at ambient temperature (14-24 degrees C) showed that 31-41% of total COD was removed. These results were significantly higher than that achieved by a septic tank (11-14%), the most common system for grey water pre-treatment, at HRT of 2-3 days. The relatively lower removal of total COD in the UASB reactor was mainly due to a higher amount of colloidal COD in the grey water, as compared to that reported in domestic wastewater. The grey water had a limited amount of nitrogen, which was mainly in particulate form (80-90%). The UASB reactor removed 24-36% and 10-24% of total nitrogen and total phosphorus, respectively, in the grey water, due to particulate nutrients removal by physical entrapment and sedimentation. The sludge characteristics of the UASB reactor showed that the system had stable performance and the recommended HRT for the reactor is 12 hours.

  19. Npvf: Hypothalamic Biomarker of Ambient Temperature Independent of Nutritional Status.

    Directory of Open Access Journals (Sweden)

    Julia Jaroslawska

    2015-06-01

    Full Text Available The mechanism by which mice, exposed to the cold, mobilize endogenous or exogenous fuel sources for heat production is unknown. To address this issue we carried out experiments using 3 models of obesity in mice: C57BL/6J+/+ (wild-type B6 mice with variable susceptibility to obesity in response to being fed a high-fat diet (HFD, B6. Ucp1-/- mice with variable diet-induced obesity (DIO and a deficiency in brown fat thermogenesis and B6. Lep-/- with defects in thermogenesis, fat mobilization and hyperphagia. Mice were exposed to the cold and monitored for changes in food intake and body composition to determine their energy balance phenotype. Upon cold exposure wild-type B6 and Ucp1-/- mice with diet-induced obesity burned endogenous fat in direct proportion to their fat reserves and changes in food intake were inversely related to fat mass, whereas leptin-deficient and lean wild-type B6 mice fed a chow diet depended on increased food intake to fuel thermogenesis. Analysis of gene expression in the hypothalamus to uncover a central regulatory mechanism revealed suppression of the Npvf gene in a manner that depends on the reduced ambient temperature and degree of exposure to the cold, but not on adiposity, leptin levels, food intake or functional brown fat.

  20. 40 CFR Appendix I to Part 50 - Interpretation of the 8-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-07-01

    ... Secondary National Ambient Air Quality Standards for Ozone 1. General. This appendix explains the data.... Primary and Secondary Ambient Air Quality Standards for Ozone. 2.1 Data Reporting and Handling Conventions... and Secondary National Ambient Air Quality Standards for Ozone I Appendix I to Part 50 Protection of...

  1. The dependence of surface temperature on IGBTs load and ambient temperature

    Directory of Open Access Journals (Sweden)

    Alexander Čaja

    2015-01-01

    Full Text Available Currently, older power electronics and electrotechnics are improvement and at the same time developing new and more efficient devices. These devices produce in their activities a significant part of the heat which, if not effectively drained, causing damage to these elements. In this case, it is important to develop new and more efficient cooling system. The most widespread of modern methods of cooling is the cooling by heat pipe. This contribution is aimed at cooling the insulated-gate bipolar transistor (IGBT elements by loop heat pipe (LHP. IGBTs are very prone to damage due to high temperatures, and therefore is the important that the surface temperature was below 100°C. It was therefore created a model that examined what impact of surface temperature on the IGBT element and heat removal at different load and constant ambient temperature.

  2. Incubation Temperature during Fetal Development Influences Morphophysiological Characteristics and Preferred Ambient Temperature of Chicken Hatchlings.

    Directory of Open Access Journals (Sweden)

    Viviane de Souza Morita

    Full Text Available Skin and feather characteristics, which play a critical role in body temperature maintenance, can be affected by incubation circumstances, such as incubation temperature. However, no study to date has assessed the influence of incubation temperature during the fetal stage on morphometric characteristics and vascular development of the skin, feather characteristics, and their relationship to hormone levels and preferred temperature in later life in chickens. Broiler breeder eggs were exposed to low (36°C, control (37.5°C, or high (39°C temperatures (treatments LT, CK, and HT, respectively from day 13 of incubation onward, because it is known that the endocrine axes are already established at this time. During this period, eggshell temperature of HT eggs (38.8±0.33°C was higher than of LT (37.4±0.08°C and CK eggs (37.8 ±0.15°C. The difference between eggshell and incubator air temperature diminished with the increasing incubation temperature, and was approximately zero for HT. HT hatchlings had higher surface temperature on the head, neck, and back, and thinner and more vascularized skin than did CK and LT hatchlings. No differences were found among treatments for body weight, total feather weight, number and length of barbs, barbule length, and plasma T4 concentration. LT hatchlings showed lower plasma T3 and GH, as well as lower T3/T4 ratio and decreased vascularity in the neck, back, and thigh skin compared to CK hatchlings. On the other hand, HT hatchlings had decreased skin thickness and increased vascularity, and preferred a higher ambient temperature compared to CK and HT hatchlings. In addition, for all treatments, surface temperature on the head was higher than of the other body regions. We conclude that changes in skin thickness and vascularity, as well as changes in thyroid and growth hormone levels, are the result of embryonic strategies to cope with higher or lower than normal incubation temperatures. Additionally exposure to

  3. 75 FR 20595 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-04-20

    ... National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur AGENCY: Environmental... Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of... policy assessment by two weeks, EPA is committed to issuing a proposal addressing the nitrogen oxides (NO...

  4. 75 FR 61486 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-10-05

    ... National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur AGENCY: Environmental... Assessment for the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: Second External Review Draft (75 FR 57463, September 21, 2010). The EPA released this...

  5. 75 FR 70258 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-11-17

    ... National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur AGENCY: Environmental... Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: Second... (summary of options for elements of the nitrogen oxides (NO X ) and sulfur oxides (SO X ) standard...

  6. 75 FR 11877 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-03-12

    ... National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur AGENCY: Environmental..., Policy Assessment for the Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur: First External Review Draft. The EPA is releasing this preliminary draft...

  7. Interacting effects of ambient temperature and food quality on the foraging ecology of small mammalian herbivores.

    Science.gov (United States)

    Camp, Meghan J; Shipley, Lisa A; Milling, Charlotte R; Rachlow, Janet L; Forbey, Jennifer S

    2018-01-01

    Both temperature and diet quality play an important role in the time and energy budgets of small mammalian herbivores. However, little is known about how temperature and diet quality interact to influence diet selection, nutrient extraction, and energetics, and how these effects might differ among species. Therefore, we examined the effects of diet quality and temperature on aspects of the foraging ecology of two species of lagomorphs, pygmy rabbits (Brachylagus idahoensis), which are small dietary specialists, and mountain cottontail rabbits (Sylvilagus nuttallii), which are larger dietary and habitat generalists. In a series of feeding experiments, we investigated 1) the effects of temperature on selection of plant fiber and the plant secondary metabolite 1,8 cineole in their diets, 2) effects of temperature and plant fiber on daily intake, digestion, and passage of food, 3) effects of plant fiber and 1,8 cineole on resting metabolic rate, and 4) how these interactions differ between the rabbit species. Both species chose to eat more total food and a greater proportion of high fiber food that passed more quickly through the digestive system in colder temperatures. However, temperature did not affect how much 1,8 cineole the rabbits consumed nor how thoroughly they digested food. Food quality affected how well they digested the dry matter in the food, but not their resting metabolic rate. Understanding how the interactions between ambient temperature and food quality affect selection of diets and intake by small mammalian herbivores, and the physiological mechanisms governing these choices, is useful for predicting how these species might respond to changes in both temperature and food quality and inform conservation and restoration strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Exposure to high ambient temperatures alters embryology in rabbits

    Science.gov (United States)

    García, M. L.; Argente, M. J.

    2017-09-01

    High ambient temperatures are a determining factor in the deterioration of embryo quality and survival in mammals. The aim of this study was to evaluate the effect of heat stress on embryo development, embryonic size and size of the embryonic coats in rabbits. A total of 310 embryos from 33 females in thermal comfort zone and 264 embryos of 28 females in heat stress conditions were used in the experiment. The traits studied were ovulation rate, percentage of total embryos, percentage of normal embryos, embryo area, zona pellucida thickness and mucin coat thickness. Traits were measured at 24 and 48 h post-coitum (hpc); mucin coat thickness was only measured at 48 hpc. The embryos were classified as zygotes or two-cell embryos at 24 hpc, and 16-cells or early morulae at 48 hpc. The ovulation rate was one oocyte lower in heat stress conditions than in thermal comfort. Percentage of normal embryos was lower in heat stress conditions at 24 hpc (17.2%) and 48 hpc (13.2%). No differences in percentage of zygotes or two-cell embryos were found at 24 hpc. The embryo development and area was affected by heat stress at 48 hpc (10% higher percentage of 16-cells and 883 μm2 smaller, respectively). Zona pellucida was thicker under thermal stress at 24 hpc (1.2 μm) and 48 hpc (1.5 μm). No differences in mucin coat thickness were found. In conclusion, heat stress appears to alter embryology in rabbits.

  9. Sub-to super-ambient temperature programmable microfabricated gas chromatography column

    Science.gov (United States)

    Robinson, Alex L.; Anderson, Lawrence F.

    2004-03-16

    A sub- to super-ambient temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by combining a thermoelectric cooler and temperature sensing on the microfabricated column. Sub-ambient temperature programming enables the efficient separation of volatile organic compounds and super-ambient temperature programming enables the elution of less volatile analytes within a reasonable time. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.

  10. Surface activated room-temperature bonding in Ar gas ambient for MEMS encapsulation

    Science.gov (United States)

    Takagi, Hideki; Kurashima, Yuichi; Takamizawa, Akifumi; Ikegami, Takeshi; Yanagimachi, Shinya

    2018-02-01

    Surface activated room-temperature bonding of Si and sapphire wafers in high-purity inert gas ambient was examined. Although surface activated bonding has been mainly performed in high vacuum, Si and sapphire wafers were successfully bonded in Ar gas ambient up to 90 kPa, which is almost atmospheric pressure. The dicing test proved that the bonding prepared in Ar gas ambient was strong enough for MEMS packaging, although the bonding strength was slightly decreased compared with that prepared in vacuum. Transmission electron microscope observation revealed that the bonding interface prepared in Ar gas ambient is almost the same as that prepared in vacuum. It means that Ar atoms in the bonding ambient do not hamper the interatomic bond formation at the bonding interface. Room-temperature bonding in gas ambient enables hermetic packaging of MEMS devices, such as inertia sensors, MEMS switches, and Cs vapor cells for MEMS atomic clocks at various pressures.

  11. Properties of Palm Oil Fuel Ash (POFA) Geopolymer Mortar Cured at Ambient Temperature

    OpenAIRE

    Olivia Monita; Mona Tambunan Lora; Saputra Edy

    2017-01-01

    Geopolymer material needs high temperature curing to produce good microstructure, high strength, and durable product. However, curing at ambient temperature is more preferable and practical in application for cast in situ geopolymer. In order to allow curing at ambient temperature, the geopolymer is mixed with mineral additives that has high calcium content such as slag, Ordinary Portland Cement (OPC) and high calcium fly ash. In this study, the Ordinary Portland Cement (OPC) was added in the...

  12. Advanced Catalysts for the Ambient Temperature Oxidation of Carbon Monoxide and Formaldehyde

    Science.gov (United States)

    Nalette, Tim; Eldridge, Christopher; Yu, Ping; Alpetkin, Gokhan; Graf, John

    2010-01-01

    The primary applications for ambient temperature carbon monoxide (CO) oxidation catalysts include emergency breathing masks and confined volume life support systems, such as those employed on the Shuttle. While Hopcalite is typically used in emergency breathing masks for terrestrial applications, in the 1970s, NASA selected a 2% platinum (Pt) on carbon for use on the Shuttle since it is more active and also more tolerant to water vapor. In the last 10-15 years there have been significant advances in ambient temperature CO oxidation catalysts. Langley Research Center developed a monolithic catalyst for ambient temperature CO oxidation operating under stoichiometric conditions for closed loop carbon dioxide (CO2) laser applications which is also advertised as having the potential to oxidize formaldehyde (HCHO) at ambient temperatures. In the last decade it has been discovered that appropriate sized nano-particles of gold are highly active for CO oxidation, even at sub-ambient temperatures, and as a result there has been a wealth of data reported in the literature relating to ambient/low temperature CO oxidation. In the shorter term missions where CO concentrations are typically controlled via ambient temperature oxidation catalysts, formaldehyde is also a contaminant of concern, and requires specially treated carbons such as Calgon Formasorb as untreated activated carbon has effectively no HCHO capacity. This paper examines the activity of some of the newer ambient temperature CO and formaldehyde (HCHO) oxidation catalysts, and measures the performance of the catalysts relative to the NASA baseline Ambient Temperature Catalytic Oxidizer (ATCO) catalyst at conditions of interest for closed loop trace contaminant control systems.

  13. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    Science.gov (United States)

    Palm, Brett B.; de Sá, Suzane S.; Day, Douglas A.; Campuzano-Jost, Pedro; Hu, Weiwei; Seco, Roger; Sjostedt, Steven J.; Park, Jeong-Hoo; Guenther, Alex B.; Kim, Saewung; Brito, Joel; Wurm, Florian; Artaxo, Paulo; Thalman, Ryan; Wang, Jian; Yee, Lindsay D.; Wernis, Rebecca; Isaacman-VanWertz, Gabriel; Goldstein, Allen H.; Liu, Yingjun; Springston, Stephen R.; Souza, Rodrigo; Newburn, Matt K.; Lizabeth Alexander, M.; Martin, Scot T.; Jimenez, Jose L.

    2018-01-01

    Secondary organic aerosol (SOA) formation from ambient air was studied using an oxidation flow reactor (OFR) coupled to an aerosol mass spectrometer (AMS) during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3) or weeks (OH) of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m-3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA) after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ˜ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10-50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds) are present in ambient air and can explain such additional SOA formation. To investigate the sources of the unmeasured SOA-forming gases during this campaign

  14. Secondary organic aerosol formation from ambient air in an oxidation flow reactor in central Amazonia

    Directory of Open Access Journals (Sweden)

    B. B. Palm

    2018-01-01

    Full Text Available Secondary organic aerosol (SOA formation from ambient air was studied using an oxidation flow reactor (OFR coupled to an aerosol mass spectrometer (AMS during both the wet and dry seasons at the Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5 field campaign. Measurements were made at two sites downwind of the city of Manaus, Brazil. Ambient air was oxidized in the OFR using variable concentrations of either OH or O3, over ranges from hours to days (O3 or weeks (OH of equivalent atmospheric aging. The amount of SOA formed in the OFR ranged from 0 to as much as 10 µg m−3, depending on the amount of SOA precursor gases in ambient air. Typically, more SOA was formed during nighttime than daytime, and more from OH than from O3 oxidation. SOA yields of individual organic precursors under OFR conditions were measured by standard addition into ambient air and were confirmed to be consistent with published environmental chamber-derived SOA yields. Positive matrix factorization of organic aerosol (OA after OH oxidation showed formation of typical oxidized OA factors and a loss of primary OA factors as OH aging increased. After OH oxidation in the OFR, the hygroscopicity of the OA increased with increasing elemental O : C up to O : C ∼ 1.0, and then decreased as O : C increased further. Possible reasons for this decrease are discussed. The measured SOA formation was compared to the amount predicted from the concentrations of measured ambient SOA precursors and their SOA yields. While measured ambient precursors were sufficient to explain the amount of SOA formed from O3, they could only explain 10–50 % of the SOA formed from OH. This is consistent with previous OFR studies, which showed that typically unmeasured semivolatile and intermediate volatility gases (that tend to lack C = C bonds are present in ambient air and can explain such additional SOA formation. To investigate the sources of the

  15. Modeling Photosensitized Secondary Organic Aerosol Formation in Laboratory and Ambient Aerosols.

    Science.gov (United States)

    Tsui, William G; Rao, Yi; Dai, Hai-Lung; McNeill, V Faye

    2017-07-05

    Photosensitized reactions involving imidazole-2-carboxaldehyde (IC) have been experimentally observed to contribute to secondary organic aerosol (SOA) growth. However, the extent of photosensitized reactions in ambient aerosols remains poorly understood and unaccounted for in atmospheric models. Here we use GAMMA 4.0, a photochemical box model that couples gas-phase and aqueous-phase aerosol chemistry, along with recent laboratory measurements of the kinetics of IC photochemistry, to analyze IC-photosensitized SOA formation in laboratory and ambient settings. Analysis of the laboratory results of Aregahegn et al. (2013) suggests that photosensitized production of SOA from limonene, isoprene, α-pinene, β-pinene, and toluene by 3 IC* occurs at or near the surface of the aerosol particle. Reactive uptake coefficients were derived from the experimental data using GAMMA 4.0. Simulations of aqueous aerosol SOA formation at remote ambient conditions including IC photosensitizer chemistry indicate less than 0.3% contribution to SOA growth from direct reactions of 3 IC* with limonene, isoprene, α-pinene, β-pinene, and toluene, and an enhancement of less than 0.04% of SOA formation from other precursors due to the formation of radicals in the bulk aerosol aqueous phase. Other, more abundant photosensitizer species, such as humic-like substances (HULIS), may contribute more significantly to aqueous aerosol SOA production.

  16. Apparatus and method for maintaining an article at a temperature that is less than the temperature of the ambient air

    Energy Technology Data Exchange (ETDEWEB)

    Klett, James; Klett, Lynn

    2018-04-03

    An apparatus for maintaining the temperature of an article at a temperature that is below the ambient air temperature includes an enclosure having an outer wall that defines an interior chamber for holding a volume of sealed air. An insert is disposed inside of the chamber and has a body that is made of a porous graphite foam material. A vacuum pump penetrates the outer wall and fluidly connects the sealed air in the interior chamber with the ambient air outside of the enclosure. The temperatures of the insert and article is maintained at temperatures that are below the ambient air temperature when a volume of a liquid is wicked into the pores of the porous insert and the vacuum pump is activated to reduce the pressure of a volume of sealed air within the interior chamber to a pressure that is below the vapor pressure of the liquid.

  17. Diet selection by Japanese quail (Coturnix coturnix japonica) in relation to ambient temperature and metabolic rate.

    Science.gov (United States)

    MacLeod, M G; Dabutha, L A

    1997-12-01

    1. A choice between a high-energy, wheat-based, low protein mixture and a lower-energy, soya-based, high protein mixture offered to growing Japanese quail at ambient temperatures of 20 degrees, 25 degrees, 30 degrees and 35 degrees C. 2. the quail were kept in open-circuit respiration calorimeters, so that diet selection could be related to energy requirement. 3. Increasing ambient temperature had no significant effect on food intake by weight, but the proportion of the high energy choice decreased and, conversely, the proportion of the lower-energy but higher-protein choice increased. 4. Energy intake was therefore negatively correlated with ambient temperature, but protein intake per unit of energy intake increased, allowing the birds to gain weight at about the same rate at all temperatures. 5. Heat production decreased as ambient temperature increased. Respiratory quotient decreased with increasing temperature, which indicates a reduced utilisation of carbohydrate as an energy source. 6. Water intake increased with temperature but there were no overt signs of heat stress and there was no significant change in body temperature. 7. Japanese quail selected a dietary mixture which maintained similar growth rates over a wide range of ambient temperature, by sustaining protein intake but altering energy intake in line with thermoregulatory energy demands.

  18. Existence of a secondary flow for a temperature dependent viscous ...

    African Journals Online (AJOL)

    We model a viscous fluid flowing between parallel plates. The viscosity depends on temperature. We investigate the properties of the velocity and we show that the temperature and velocity fields have two solutions. The existence of two velocity solutions is new. This means that there exist secondary flows. Journal of the ...

  19. THERMAL COMFORT FOR REQUIRED BODY TEMPERATURES AND AMBIENT CONDITIONS

    OpenAIRE

    KAYNAKLI, Ömer; YAMANKARADENİZ, Recep

    2010-01-01

    ABSTRACTIn industrialized countries about 90 % of the time is spent indoors. The environmental parameters affecting indoor thermal comfort are air temperature, humidity, air velocity and mean radiant temperature. In assessing thermal environment, besides these environmental parameters, we should also consider some personal parameters such as clothing and human activity. In this study, we tried to determine the thermal comfort factors with reference to required skin temperature (tsk,req) and s...

  20. Effects of ambient oxygen concentration on soot temperature and concentration for biodiesel and diesel spray combustion

    KAUST Repository

    Zhang, Ji

    2015-06-01

    Ambient oxygen concentration, a key variable directly related to exhaust gas recirculation (EGR) levels in diesel engines, plays a significant role in particulate matter (PM) and nitrogen oxides (NOx) emissions. The utilization of biodiesel in diesel engines has been investigated over the last decades for its renewable characteristics and lower emissions compared to diesel. In an earlier work, we demonstrated that the soot temperature and concentration of biodiesel were lower than diesel under regular diesel engine conditions without EGR. Soot concentration was quantified by a parameter called KL factor. As a continuous effort, this paper presents an experimental investigation of the ambient oxygen concentration on soot temperature and KL factor during biodiesel and diesel spray combustion. The experiment was implemented in a constant volume chamber system, where the ambient oxygen concentration varied from 21 to 10% and the ambient temperature was kept to 1,000 K. A high speed two-color pyrometry technique was used to measure transient soot temperature and the KL factor of the spray flame. The soot temperature of biodiesel is found to be lower than that of diesel under the same conditions, which follows the same trend from our previous results found when the ambient temperature changes to 21% oxygen conditions. A reduction in ambient oxygen concentration generally reduces the soot temperature for both fuels. However, this is a complicated effect on soot processes as the change of oxygen concentration greatly affects the balance between soot formation and oxidation. The KL factor is observed to be the highest at 12% O2 for diesel and 18% O2 for biodiesel, respectively. On the other hand, the 10% O2 condition shows the lowest KL factor for both fuels. These results can provide quantitative experimental evidences to optimize the ambient oxygen concentration for diesel engines using different fuels for better emissions characteristics. © 2014 American Society of

  1. Vitrification of high level nuclear waste inside ambient temperature disposal containers using inductive heating: The SMILE system

    International Nuclear Information System (INIS)

    Powell, J.; Reich, M.; Barletta, R.

    1996-01-01

    A new approach, termed SMILE (Small Module Inductively Loaded Energy), for the vitrification of high level nuclear wastes (HLW) is described. Present vitrification systems liquefy the HLW solids and associated frit material in large high temperature melters. The molten mix is then poured into small (∼1 m 3 ) disposal canisters, where it solidifies and cools. SMILE eliminates the separate, large high temperature melter. Instead, the BLW solids and frit melt inside the final disposal containers, using inductive heating. The contents then solidify and cool in place. The SMILE modules and the inductive heating process are designed so that the outer stainless can of the module remains at near ambient temperature during the process cycle. Module dimensions are similar to those of present disposal containers. The can is thermally insulated from the high temperature inner container by a thin layer of refractory alumina firebricks. The inner container is a graphite crucible lined with a dense alumina refractory that holds the HLW and fiit materials. After the SMILE module is loaded with a slurry of HLW and frit solids, an external multi-turn coil is energized with 30-cycle AC current. The enclosing external coil is the primary of a power transformer, with the graphite crucible acting as a single turn ''secondary.'' The induced current in the ''secondary'' heats the graphite, which in turn heats the HLW and frit materials. The first stage of the heating process is carried out at an intermediate temperature to drive off remnant liquid water and water of hydration, which takes about 1 day. The small fill/vent tube to the module is then sealed off and the interior temperature raised to the vitrification range, i.e., ∼1200C. Liquefaction is complete after approximately 1 day. The inductive heating then ceases and the module slowly loses heat to the environment, allowing the molten material to solidify and cool down to ambient temperature

  2. Vitrification of high level nuclear waste inside ambient temperature disposal containers using inductive heating: The SMILE system

    Energy Technology Data Exchange (ETDEWEB)

    Powell, J.; Reich, M.; Barletta, R.

    1996-03-01

    A new approach, termed SMILE (Small Module Inductively Loaded Energy), for the vitrification of high level nuclear wastes (HLW) is described. Present vitrification systems liquefy the HLW solids and associated frit material in large high temperature melters. The molten mix is then poured into small ({approximately}1 m{sup 3}) disposal canisters, where it solidifies and cools. SMILE eliminates the separate, large high temperature melter. Instead, the BLW solids and frit melt inside the final disposal containers, using inductive heating. The contents then solidify and cool in place. The SMILE modules and the inductive heating process are designed so that the outer stainless can of the module remains at near ambient temperature during the process cycle. Module dimensions are similar to those of present disposal containers. The can is thermally insulated from the high temperature inner container by a thin layer of refractory alumina firebricks. The inner container is a graphite crucible lined with a dense alumina refractory that holds the HLW and fiit materials. After the SMILE module is loaded with a slurry of HLW and frit solids, an external multi-turn coil is energized with 30-cycle AC current. The enclosing external coil is the primary of a power transformer, with the graphite crucible acting as a single turn ``secondary.`` The induced current in the ``secondary`` heats the graphite, which in turn heats the HLW and frit materials. The first stage of the heating process is carried out at an intermediate temperature to drive off remnant liquid water and water of hydration, which takes about 1 day. The small fill/vent tube to the module is then sealed off and the interior temperature raised to the vitrification range, i.e., {approximately}1200C. Liquefaction is complete after approximately 1 day. The inductive heating then ceases and the module slowly loses heat to the environment, allowing the molten material to solidify and cool down to ambient temperature.

  3. Stable oxygen isotope reconstruction of ambient temperature during the collapse of a cod (Gadus morhua) fishery.

    Science.gov (United States)

    Jones, J Brin; Campana, Steven E

    2009-09-01

    Changing environmental conditions set against a backdrop of high exploitation can result in severe consequences for commercially harvested stocks. The collapse of the Eastern Scotian Shelf cod (Gadus morhua L.) off eastern Canada was primarily due to overexploitation but may have been exacerbated by a widespread temperature decline. Recent studies have called for accurate determination of ambient temperature (the actual temperature exposure history of the fish) before discarding environmental conditions as a factor in the collapse. We used the stable oxygen isotope composition of otoliths (delta18O(oto)) to reconstruct the ambient temperature history of Eastern Scotian Shelf cod from 1970 to 2000 in order to determine whether the stock experienced the temperature decline or shifted their distribution to avoid it. To correct delta18O(oto) for seawater isotope content (deltaO(w)), we generated a new meta-equation for the relationship between delta18O(w) (per mil) and salinity (S, in psu) on the Eastern Scotian Shelf: delta18O(w) = 0.539 x S - 18.790. The ambient temperature series revealed that the large-scale geographic distribution of mature cod remained constant through the cooling period, although their ambient temperature was cooler than expected in warmer periods and warmer than expected in cooler periods, indicating small-scale thermoregulatory movement. Although the mean hydrographic temperature was 4 degrees C, mature cod usually inhabited the coldest available waters (mean ambient temperature = 3 degrees C), while the juveniles usually inhabited warmer waters (mean ambient temperature = 5.5 degrees C). Length-at-age was significantly related to ambient temperature, especially in the early years of growth, and therefore declining ambient temperatures were at least partially responsible for declines in asymptotic length (up to age 8 yr). The most active thermoregulatory movement occurred during a moderate warming period; therefore extreme warming events (such

  4. Assessment of ambient-temperature, high-resolution detectors for nuclear safeguards applications

    International Nuclear Information System (INIS)

    Ruhter, W.D.; McQuaid, J.H.; Lavietes, A.

    1993-01-01

    High-resolution, gamma- and x-ray spectrometry are used routinely in nuclear safeguards verification measurements of plutonium and uranium in the field. These measurements are now performed with high-purity germanium (HPGe) detectors that require cooling liquid-nitrogen temperatures, thus limiting their utility in field and unattended safeguards measurement applications. Ambient temperature semiconductor detectors may complement HPGe detectors for certain safeguards verification applications. Their potential will be determined by criteria such as their performance, commercial availability, stage of development, and costs. We have conducted as assessment of ambient temperature detectors for safeguards measurement applications with these criteria in mind

  5. Ambient Temperature Based Thermal Aware Energy Efficient ROM Design on FPGA

    DEFF Research Database (Denmark)

    Saini, Rishita; Bansal, Neha; Bansal, Meenakshi

    2015-01-01

    Thermal aware design is currently gaining importance in VLSI research domain. In this work, we are going to design thermal aware energy efficient ROM on Virtex-5 FPGA. Ambient Temperature, airflow, and heat sink profile play a significant role in thermal aware hardware design life cycle. Ambient...... temperature is a temperature of surroundings. Airflow is measured in Linear Feet per Minute (LFM). Medium profile and high profile are two different heat sink profile available in XPower analyzer.When frequency goes from 4.0GHz to 1.0GHz, there is 21.8% reduction in clock power, 75% reduction in I/O Power, 35...

  6. 40 CFR 53.55 - Test for effect of variations in power line voltage and ambient temperature.

    Science.gov (United States)

    2010-07-01

    ... line voltage and ambient temperature. 53.55 Section 53.55 Protection of Environment ENVIRONMENTAL... power line voltage and ambient temperature. (a) Overview. (1) This test procedure is a combined... temperature. Tests shall be conducted in a temperature-controlled environment over four 6-hour time periods...

  7. Ambient temperature during torpor affects NREM sleep EEG during arousal episodes in hibernating European ground squirrels

    NARCIS (Netherlands)

    Strijkstra, AM; Daan, S

    1997-01-01

    Ambient temperature (T-a) systematically affects the frequency of arousal episodes in mammalian hibernation. This variation might hypothetically be attributed to temperature effects on the rate of sleep debt increase in torpor. We studied this rate by recording sleep electroencephalogram (EEG) in

  8. Pressure drop in packed beds of spherical particles at ambient and elevated air temperatures

    Directory of Open Access Journals (Sweden)

    Pešić Radojica

    2015-01-01

    Full Text Available The aim of this work was the experimental investigation of the particle friction factor for air flow through packed bed of particles at ambient and elevated temperatures. The experiments were performed by measuring the pressure drop across the packed bed, heated to the desired temperature by hot air. Glass spherical particles of seven different diameters were used. The temperature range of the air flowing through the packed bed was from 20ºC to 350ºC and the bed voidages were from 0.3574 to 0.4303. The obtained results were correlated using a number of available literature correlations. The overall best fit of all of the experimental data was obtained using Ergun [1] equation, with mean absolute deviation of 10.90%. Ergun`s equation gave somewhat better results in correlating the data at ambient temperature with mean absolute deviation of 9.77%, while correlation of the data at elevated temperatures gave mean absolute deviation of 12.38%. The vast majority of the correlations used gave better results when applied to ambient temperature data than to the data at elevated temperatures. Based on the results obtained, Ergun [1] equation is proposed for friction factor calculation both at ambient and at elevated temperatures. [Projekat Ministarstva nauke Republike Srbije, br. ON172022

  9. The influence of ambient temperature on diet in the Great Tit

    NARCIS (Netherlands)

    Wansink, Dennis; Tinbergen, Joost M.

    1994-01-01

    In winter, Great Tits Parus major have a mixed diet of insect food and seeds. Field data suggest a dietary shift towards seeds with declining ambient temperatures. We hypothesised that Great Tits increase their preference for seeds with decreasing temperatures to raise their fat intake over time. An

  10. An apparatus to measure the thermal conductivity of insulation panels at sub-ambient temperature

    NARCIS (Netherlands)

    Vanapalli, Srinivas; Klünder, T.; Hegeman, I.; Tolboom, A.H.; ter Brake, Hermanus J.M.

    2017-01-01

    A single-sided guarded-plate apparatus has been developed to measure the thermal conductivity of insulation panels of sub-meter size at sub-ambient temperatures ranging from 250 to 300 K. This apparatus allows thermal conductivity measurements to be performed at large temperature differences

  11. Does maternal exposure during pregnancy to higher ambient temperature increase the risk of hypospadias?

    Science.gov (United States)

    Kilinc, Muhammet Fatih; Cakmak, Sedat; Demir, Demirhan Orsan; Doluoglu, Omer Gokhan; Yildiz, Yildiray; Horasanli, Kaya; Dalkilic, Ayhan

    2016-12-01

    The association between ambient temperature that the mother is exposed to during pregnancy and hypospadias has not been investigated by the studies, although the recent studies showed the correlation between some congenital malformations (congenital heart disease, neural tube defect, etc.) and ambient temperature. The aim was to investigate the relation between hypospadias and the ambient temperatures that the mother is exposed to during her pregnancy. The data of patients with hypospadias that had their gestational periods in Ankara and Istanbul regions, and had other urological treatments (circumcision, urinary tract infection, pyeloplasty, nephrolithotomy, etc.) between January 2000 and November 2015 were analyzed retrospectively. The ambient temperature at 8-14 weeks of gestation was investigated for each patient by reviewing the data of the General Directorate of Meteorology, since this period was risky for development of hypospadias. The data including ambient temperature that the pregnant mother was exposed to, maternal age, parity, economical status, gestational age at birth, and birth weight were compared between two groups. The retrospective nature of the study may be a potential source for selection bias. The data of 1,709 children that had hypospadias repair and 4,946 children that had other urological treatments between 2000 and 2015 were retrospectively analyzed. There were no differences between the groups for maternal age, parity, economical status, gestational age at birth, and birth weight (Table). Analysis of exposed maximum and average ambient temperatures at 8-14 weeks of gestation revealed that July and August, hot periods in summer time, were more prevalent in the hypospadias group (p = 0.01). The average and maximum monthly ambient temperatures during summer increased the risk for hypospadias (OR, 1.32; 95% CI, 1.08-1.52; and OR, 1.22; 95% CI, 0.99-1.54, respectively. In this paper, we evaluated the relation between hypospadias and the

  12. Effects of elevated ambient temperature on embryo implantation in rats

    African Journals Online (AJOL)

    Yomi

    2012-03-22

    E2 ratio in the control group and in the group exposed to elevated temperature at three stages: day 5 afternoon, day 5 evening and day 6 of pregnancy. (A) Progesterone concentrations (ng/ml). (B) Estradiol concentrations ...

  13. Ambient air pollution, temperature and kawasaki disease in Shanghai, China.

    Science.gov (United States)

    Lin, Zhijing; Meng, Xia; Chen, Renjie; Huang, Guoying; Ma, Xiaojing; Chen, Jingjing; Huang, Min; Huang, Meirong; Gui, Yonghao; Chu, Chen; Liu, Fang; Kan, Haidong

    2017-11-01

    Kawasaki disease (KD) is a kind of pediatric vasculitis of unknown etiology which mainly affects the development of coronary artery aneurysms. Few studies have explored the potential environmental risk factors on KD incidence. We performed a time-series analysis to investigate the associations between air pollution and temperature and KD in Shanghai, China. We collected daily-hospitalized KD patients that were admitted in major pediatric specialty hospitals located in the urban areas of Shanghai from 2001 to 2010. The over-dispersed generalized additive model was used to estimate the effects of air pollutants on KD incidence on each day. Then, this model was combined with a distributed lag non-linear model to estimate the cumulative effects of temperature over a week. There were positive but statistically insignificant associations between three major air pollutants and KD incidence. The association between daily mean temperature and KD was generally J-shaped with higher risks on hot days. The cumulative relative risk of KD at extreme hot temperature (99th percentile, 32.4 °C) over a week was 1.91 [95% confidence interval (CI): 1.13, 3.23], compared with the referent temperature (10.0 °C). This study suggested that a short-term exposure to high temperature may significantly increase the incidence of KD, and the evidence linking air pollution and KD incidence was limited. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Fuelling of TCA cycle in hepatic cells Marwari goat during ambient temperature associated stress

    Directory of Open Access Journals (Sweden)

    Kataria N.

    2010-11-01

    Full Text Available The present study was launched to assess the effect of extreme ambient temperature associated stress on fuelling of TCA cycle in hepatic cells of Marwari goat. Based on the fact that whenever a hepatocyte needs fuel for TCA cycle, the activity of enzyme glutamate dehydrogenase (GD increases making alpha-ketoglutarate available for TCA cycle, 600 apparently healthy Marwari goats of either sex, between 6 months to 3 years of age were screened and blood samples were collected during moderate, cold and hot ambient temperature periods to determine the serum glutamate dehydrogenase enzyme and glucose concentration. The mean value of serum GD was significantly (p≤0.05 higher during cold and hot ambient temperature periods in comparison to overall moderate mean value. However, the rise was greater in cold (2.20 times than hot ambient temperature (1.19 times. The serum GD activity was higher in male and younger animals. Serum glucose concentration showed a reverse trend as compared to serum GD activity. The results indicated that in cold condition associated stress the fuelling to TCA cycle was more than moderate and hot ambient temperature periods. Serum GD activity was also found related with glucose homeostasis. Further the study has shown that variations in the enzyme levels are not always pathological and while interpreting clinical data, a clinician must consider these variations.

  15. Microbiological Studies of Semi-Preserved Natural Condiments Paste Stored in Refrigerator and Ambient Temperature

    Science.gov (United States)

    Dien, H. A.; Montolalu, R. I.; Mentang, F.; Mandang, A. S. K.; Rahmi, A. D.; Berhimpon, S.

    2018-01-01

    The aims of this studies were to prepare juice and raw condiment to be come semipreserve pastes, and to do microbial assessments on the both pastes during storing in refrigerator and ambient temperatures. For both pastes in refrigerator, samples were taken at 0, 2, 4, 5, 6, 8, 10, 15, 20, 25, and 30 days, and in ambient temperature samples were taken at 0, 1, 2, 3, 4, and 6 days. Assessment were done for TPC, total coliform and E. coli, Salmonella sp, Staphylococcus sp., Vibrio sp., pH and water content. The results shown that juice paste stored in refrigerator still good until 30 days (TPC 1,5x104 CFU/g), and in ambient temperature still good until 6 days (2x104 CFU/g). Condiment paste stored in refrigerator still good until 30 days (6.5x103 CFU/g), and in ambient temperature still good until 6 days (1.17x104 CFU/g). However, recommended that condiment paste stored in ambient temperature only until 4 days (7.3x103CFU/g), while that juice paste until 5 days (7.8x103CFU/g). There were no pathogenic bacteria found in all samples.

  16. Correlation between corneal and ambient temperature with particular focus on polar conditions.

    Science.gov (United States)

    Slettedal, Jon Klokk; Ringvold, Amund

    2015-08-01

    To examine the relationship between human corneal and environmental temperature. An infrared camera was used to measure the corneal surface temperature in a group of healthy volunteers as well as in an experimental setting with donor corneas and an artificial anterior chamber, employing circulating saline at +37°C. Liquid nitrogen was used to obtain a very low temperature in the experimental setting. High ambient temperature measurements were performed in a sauna. In healthy volunteers, the cornea required at least 20-30 min to adapt to change in ambient temperature. The relationship between corneal and external temperature was relatively linear. At the two extremes, +83°C and -40°C, the corneal temperature was +42°C and +25.1°C, respectively. In the experimental setting, corneal temperature was +24.3°C at air temperature -40°C. A rather stable aqueous humour temperature of +37°C and high thermal conductivity of the corneal tissue prevent corneal frostbite even at extremely low ambient temperatures. © 2015 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  17. [Insulation characteristics of transport containers for organ cultured donor corneas under different ambient temperatures].

    Science.gov (United States)

    Schroeter, J; Meltendorf, C

    2009-08-01

    The aim of this study was to evaluate the ability of different transport containers to maintain an inside temperature between +10 and +40 degrees C, which is supposed to be safe for organ cultured donor corneas in dextran containing culture media, for a period of 24 hours at ambient temperatures of -10, 0, +10 and +50 degrees C. 3 containers were tested: 1. Styrofoam box with 2.5 cm thick walls (Graft-tec, AL.CHI.MI.A., Padova, Italy). 2. Thermos jug 0.5 litre (Primus, Solna, Sweden), a double walled metal jug. 3. ThempShell-22 degrees (VWR International, Darmstadt, Germany), a box of gel filled plastic elements. The containers were exposed to -10, 0, +10 and +50 degrees C for 24 hours each. A continuous temperature recording of the ambient and internal environments was performed using electronic thermometers (Mini Intelligent Logger, Escort). The inside temperature of the styrofoam box reached the outside temperature level after 80 - 230 min for all tested settings. The Thermos jug reached the outside temperature approximately after 5 hours. In contrast, the inside temperature of the TempShell-22 degrees CC was at -10 degrees C outside temperature 21 degrees C after 6 hours, 19 degrees C after 12 hours and 12 degrees C after 24 hours. At an ambient temperature of 0 and +10 degrees C the inside temperature of the TempShell-22 degrees C was 19.2 and 17.8 degrees C respectively after 24 hours. An ambient temperature of + 50 degrees C led to an inside temperature of the TempShell-22 degrees C of 30.5 degrees C after 6, 38.3 degrees C after 12 hours and 47.0 degrees C after 24 hours. A standard Styrofoam box with 2.5 cm thick walls and the tested thermos jug are not suitable to assure a safe temperature range. The TempShell-22 degrees C assures a safe temperature range for low ambient temperatures (-10 to +10 degrees C) for at least 24 hours and for an ambient temperature of +50 degrees C for at least 10 hours. Georg Thieme Verlag KG Stuttgart.New York.

  18. Research on floral timing by ambient temperature comes into blossom

    NARCIS (Netherlands)

    Verhage, D.S.L.; Angenent, G.C.; Immink, R.G.H.

    2014-01-01

    The floral transition is an essential process in the life cycle of flower-bearing plants, because their reproductive success depends on it. To determine the right moment of flowering, plants respond to many environmental signals, including day length, light quality, and temperature. Small changes in

  19. Mathematical Modelling of Effect of Ambient Temperature and ...

    African Journals Online (AJOL)

    Temperature distributions on the soil surface strongly depend on the state of the processes of mass and energy exchanges (radiation and convection, evaporation and water condensation, supply of water through precipitation and gaseous exchange). It was assumed that soil medium is homogeneous and parameters ...

  20. Ambient temperature stress-corrosion cracking of sensitized stainless steels

    International Nuclear Information System (INIS)

    Sieradzki, K.; Isaacs, H.S.; Newman, R.C.

    1982-01-01

    Stress-corrosion cracking of sensitized Type 304 steel in low temperature borated water has been observed. The probable role of low levels of chloride ions or sulfur-containing ions is described, including the relationship of the phenomenon to polythionic acid cracking. The mechanism of the sulfur-induced cracking and its usefulness as a test for sensitization are outlined

  1. Brassinosteroid signaling-dependent root responses to prolonged elevated ambient temperature.

    Science.gov (United States)

    Martins, Sara; Montiel-Jorda, Alvaro; Cayrel, Anne; Huguet, Stéphanie; Roux, Christine Paysant-Le; Ljung, Karin; Vert, Grégory

    2017-08-21

    Due to their sessile nature, plants have to cope with and adjust to their fluctuating environment. Temperature elevation stimulates the growth of Arabidopsis aerial parts. This process is mediated by increased biosynthesis of the growth-promoting hormone auxin. How plant roots respond to elevated ambient temperature is however still elusive. Here we present strong evidence that temperature elevation impinges on brassinosteroid hormone signaling to alter root growth. We show that elevated temperature leads to increased root elongation, independently of auxin or factors known to drive temperature-mediated shoot growth. We further demonstrate that brassinosteroid signaling regulates root responses to elevated ambient temperature. Increased growth temperature specifically impacts on the level of the brassinosteroid receptor BRI1 to downregulate brassinosteroid signaling and mediate root elongation. Our results establish that BRI1 integrates temperature and brassinosteroid signaling to regulate root growth upon long-term changes in environmental conditions associated with global warming.Moderate heat stimulates the growth of Arabidopsis shoots in an auxin-dependent manner. Here, Martins et al. show that elevated ambient temperature modifies root growth by reducing the BRI1 brassinosteroid-receptor protein level and downregulating brassinosteroid signaling.

  2. Polymer Coated Electrodes in Ambient Temperature Molten Salts.

    Science.gov (United States)

    1983-08-01

    PERFORMING ORG. REPORT NUMBER ~7. AUTHOR(*) S. CONTRACT OR GRANT NuMBER(a) P.G. Pickup and Robert A. Osteryoung N00014-79-C-0682 9. PERFORMING ORGANIZATION...glassy carbon ..-r electrodes in various compositions of the am- blent temperature molten salt system aluminum 00 6 ov chloride:n-butylpyridinium...Or TrVT AJf A I I START SECO:REFERENCES N HERE. 1. R. W. Murray, ’Chemically Modified Elect- rodes", Chapter 3 in Electroanalytical Chemistry, Vol. 13

  3. Ambient-temperature incubation for the field detection of Escherichia coli in drinking water.

    Science.gov (United States)

    Brown, J; Stauber, C; Murphy, J L; Khan, A; Mu, T; Elliott, M; Sobsey, M D

    2011-04-01

     Escherichia coli is the pre-eminent microbiological indicator used to assess safety of drinking water globally. The cost and equipment requirements for processing samples by standard methods may limit the scale of water quality testing in technologically less developed countries and other resource-limited settings, however. We evaluate here the use of ambient-temperature incubation in detection of E. coli in drinking water samples as a potential cost-saving and convenience measure with applications in regions with high (>25°C) mean ambient temperatures.   This study includes data from three separate water quality assessments: two in Cambodia and one in the Dominican Republic. Field samples of household drinking water were processed in duplicate by membrane filtration (Cambodia), Petrifilm™ (Cambodia) or Colilert® (Dominican Republic) on selective media at both standard incubation temperature (35–37°C) and ambient temperature, using up to three dilutions and three replicates at each dilution. Matched sample sets were well correlated with 80% of samples (n = 1037) within risk-based microbial count strata (E. coli CFU 100 ml−1 counts of 1000), and a pooled coefficient of variation of 17% (95% CI 15–20%) for paired sample sets across all methods.   These results suggest that ambient-temperature incubation of E. coli in at least some settings may yield sufficiently robust data for water safety monitoring where laboratory or incubator access is limited.

  4. Properties of Palm Oil Fuel Ash (POFA Geopolymer Mortar Cured at Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Olivia Monita

    2017-01-01

    Full Text Available Geopolymer material needs high temperature curing to produce good microstructure, high strength, and durable product. However, curing at ambient temperature is more preferable and practical in application for cast in situ geopolymer. In order to allow curing at ambient temperature, the geopolymer is mixed with mineral additives that has high calcium content such as slag, Ordinary Portland Cement (OPC and high calcium fly ash. In this study, the Ordinary Portland Cement (OPC was added in the Palm Oil Fuel Ash (POFA geopolymer mortar to induce setting and hardening at ambient temperature. Setting time, compressive strength and porosity of the POFA geopolymer mortar were measured. The OPC was added into the geopolymer at dosages of 0%, 20%, 25%, 30%, 35%, and 40%. The alkaline activator used was a combination of NaOH (16M and sodium silicate with a ratio of 2.5 by mass. The POFA geopolymer mortar were cast and cured at ambient temperature. Results show that addition of 35% OPC increased the setting time by 99.44%, increased the compressive strength of mortar by 95.46% and decreased the porosity by 5.27% at 28 days. It can be concluded that inclusion of the OPC could improve the setting and final strength of the geopolymer material.

  5. Soot measurements for diesel and biodiesel spray combustion under high temperature highly diluted ambient conditions

    KAUST Repository

    Zhang, Ji

    2014-11-01

    This paper presents the soot temperature and KL factor for biodiesel, namely fatty acid methyl ester (FAME) and diesel fuel combustion in a constant volume chamber using a two-color technique. The KL factor is a parameter for soot concentration, where K is an absorption coefficient and proportional to the number density of soot particles, L is the geometric thickness of the flame along the optical detection axis, and KL factor is proportional to soot volume fraction. The main objective is to explore a combustion regime called high-temperature and highly-diluted combustion (HTHDC) and compare it with the conventional and low-temperature combustion (LTC) modes. The three different combustion regimes are implemented under different ambient temperatures (800 K, 1000 K, and 1400 K) and ambient oxygen concentrations (10%, 15%, and 21%). Results are presented in terms of soot temperature and KL factor images, time-resolved pixel-averaged soot temperature, KL factor, and spatially integrated KL factor over the soot area. The time-averaged results for these three regimes are compared for both diesel and biodiesel fuels. Results show complex combined effects of the ambient temperature and oxygen concentration, and that two-color temperature for the HTHDC mode at the 10% oxygen level can actually be lower than the conventional mode. Increasing ambient oxygen and temperature increases soot temperature. Diesel fuel results in higher soot temperature than biodiesel for all three regimes. Results also show that diesel and biodiesel fuels have very different burning and sooting behavior under the three different combustion regimes. For diesel fuel, the HTHDC regime offers better results in terms of lower soot than the conventional and LTC regimes, and the 10% O2, 1400 K ambient condition shows the lowest soot concentration while maintaining a moderate two-color temperature. For biodiesel, the 15% O2, 800 K ambient condition shows some advantages in terms of reducing soot

  6. Effects of Elevated Ambient Temperature on Reproductive Outcomes and Offspring Growth Depend on Exposure Time

    Directory of Open Access Journals (Sweden)

    Huda Yahia Hamid

    2012-01-01

    Full Text Available Reproductive performance has been shown to be greatly affected by changes in environmental factors, such as temperature. However, it is also crucial to identify the particular stage of pregnancy that is most adversely affected by elevated ambient temperature. The aims of this study were to determine the effect on reproductive outcomes of exposure to elevated ambient temperature during different stages of pregnancy and to determine the effect of prenatal heat stress on offspring growth. Sixty pregnant rats were used in this study. The rats were divided equally into four groups as group 1 (control, group 2 (exposed to elevated temperature following implantation, group 3 (exposed to elevated temperature during pre- and periimplantation, and group 4 (exposed to elevated temperature during pre- and periimplantation and following implantation. Groups 3 and 4 had prolonged gestation periods, reduced litter sizes, and male-biased sex ratios. Moreover, the growth patterns of group 3 and 4 pups were adversely affected by prenatal exposure to elevated temperature. The differences between group 1 and group 3 and between group 1 and group 4 were highly significant. However, no significant differences were observed between groups 1 and 2 in the gestation length, sex ratios, and growth patterns. Thus, it can be concluded that exposure to elevated ambient temperature during pre- and periimplantation has stronger adverse effects on reproductive outcomes and offspring growth than postimplantation exposure.

  7. Effect of ambient temperature and energy demands on digestive functions in leaf-eared mice (Phyllotis darwini) from central Chile

    Science.gov (United States)

    Bozinovic, F.; Nespolo, Roberto F.

    The leaf-eared mouse, Phyllotis darwini, is a nocturnal rodent inhabiting the semiarid and Mediterranean habitats of northern and central Chile. Previous observations suggested that in the field, individuals may change food intake according to seasonal changes in ambient temperature. We therefore anticipated that P. darwini should increase food intake in response to lower ambient temperature. As predicted, results of food trials and digestive measurements demonstrated that P. darwini increases food intake and assimilation at lower ambient temperatures but does not increase food mean retention time. At lower ambient temperatures, individuals increase digestive tract size thus improving body mass maintenance and perhaps survival during winter.

  8. Dependence of electric strength on the ambient temperature

    International Nuclear Information System (INIS)

    Čaja, Alexander; Nemec, Patrik; Malcho, Milan

    2014-01-01

    At present, the volume concentration of electronic components in their miniaturization to different types of microchips and increasing their performance raises the problem of cooling such elements due to the increasing density of heat flow of heat loss. Compliance with safe operating temperature of active semiconductor element is very closely related to the reliability and durability not only components, but also the entire device. Often it is also necessary to electrically isolate the unit from the side of the cooler air. Cooling demand by natural convection is typical for applications with high operating reliability. To the reliability of the system for removing heat loss increased, it is necessary to minimize need to use the mechanically or electrically powered elements, such as circulation pumps or fans. Experience to date with applications of heat pipe in specific systems appears to be the most appropriate method of cooling

  9. Dependence of electric strength on the ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Čaja, Alexander, E-mail: alexander.caja@fstroj.uniza.sk, E-mail: patrik.nemec@fstroj.uniza.sk, E-mail: milan.malcho@fstroj.uniza.sk; Nemec, Patrik, E-mail: alexander.caja@fstroj.uniza.sk, E-mail: patrik.nemec@fstroj.uniza.sk, E-mail: milan.malcho@fstroj.uniza.sk; Malcho, Milan, E-mail: alexander.caja@fstroj.uniza.sk, E-mail: patrik.nemec@fstroj.uniza.sk, E-mail: milan.malcho@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engeneering, Univerzitná 1, 010 26 Žilina (Slovakia)

    2014-08-06

    At present, the volume concentration of electronic components in their miniaturization to different types of microchips and increasing their performance raises the problem of cooling such elements due to the increasing density of heat flow of heat loss. Compliance with safe operating temperature of active semiconductor element is very closely related to the reliability and durability not only components, but also the entire device. Often it is also necessary to electrically isolate the unit from the side of the cooler air. Cooling demand by natural convection is typical for applications with high operating reliability. To the reliability of the system for removing heat loss increased, it is necessary to minimize need to use the mechanically or electrically powered elements, such as circulation pumps or fans. Experience to date with applications of heat pipe in specific systems appears to be the most appropriate method of cooling.

  10. Respiratory alkalosis and primary hypocapnia in Labrador Retrievers participating in field trials in high-ambient-temperature conditions.

    Science.gov (United States)

    Steiss, Janet E; Wright, James C

    2008-10-01

    To determine whether Labrador Retrievers participating in field trials develop respiratory alkalosis and hypocapnia primarily in conditions of high ambient temperatures. 16 Labrador Retrievers. At each of 5 field trials, 5 to 10 dogs were monitored during a test (retrieval of birds over a variable distance on land [1,076 to 2,200 m]; 36 assessments); ambient temperatures ranged from 2.2 degrees to 29.4 degrees C. For each dog, rectal temperature was measured and a venous blood sample was collected in a heparinized syringe within 5 minutes of test completion. Blood samples were analyzed on site for Hct; pH; sodium, potassium, ionized calcium, glucose, lactate, bicarbonate, and total CO2 concentrations; and values of PvO2 and PvCO2. Scatterplots of each variable versus ambient temperature were reviewed. Regression analysis was used to evaluate the effect of ambient temperature ( 21 degrees C) on each variable. Compared with findings at ambient temperatures 21 degrees C; rectal temperature did not differ. Two dogs developed signs of heat stress in 1 test at an ambient temperature of 29 degrees C; their rectal temperatures were higher and PvCO2 values were lower than findings in other dogs. When running distances frequently encountered at field trials, healthy Labrador Retrievers developed hyperthermia regardless of ambient temperature. Dogs developed respiratory alkalosis and hypocapnia at ambient temperatures > 21 degrees C.

  11. Microturbogas cogeneration systems for distributed generation: Effects of ambient temperature on global performance and components’ behavior

    International Nuclear Information System (INIS)

    Caresana, F.; Pelagalli, L.; Comodi, G.; Renzi, M.

    2014-01-01

    Highlights: • Electrical power reduces with temperature, heat recovery remains almost constant. • Thermal-to-electrical power ratio increases with ambient temperature. • Not only the density of sucked air decreases but also its volumetric flow. • Putting a limit to shaft speed causes TIT to decrease with ambient temperature. • Power reduction with ambient temperature more than doubles that of great GTs. - Abstract: Microturbines (MGTs) are a relatively new technology that is currently attracting a lot of interest in the distributed generation market. Particularly interesting is their use as backup source for integrating photovoltaic panels or/and wind turbines in hybrid systems. In this case the sensitivity to ambient conditions of the MGT adds to that of the renewables and the knowledge of the effects of ambient conditions on its performance becomes a key subject both for the sizing of the energy system and for its optimal dynamic control. Although the dependence of medium/large gas turbines performance on atmospheric conditions is well known and documented in literature, there are very limited reports available on MGTs and they regard only global parameters. The paper aims at filling this lack of information by analyzing the ambient temperature effect on the global performance of an MGT in cogeneration arrangement and by entering in detail into its machines’ behavior. A simulation code, tuned on experimental data, is used for this purpose. Starting from the nominal ISO conditions, electrical power output is shown to decrease with ambient temperature at a rate of about 1.22%/°C, due to a reduction of both air density and volumetric flow. Meanwhile, thermal to electrical power ratio increases at a rate of about 1.30%/°C. As temperature increases compressor delivers less air at a lower pressure, and the turbine expansion ratio and mass flow reduce accordingly. With the in-use control system the turbine inlet temperature reduces at a rate of 0.07%/

  12. SRF Performance of CEBAF After Thermal Cycle to Ambient Temperature

    CERN Document Server

    Rimmer, Robert; Preble, Joseph P; Reece, Charles E

    2005-01-01

    In September 2003, in the wake of Hurricane Isabel, JLab was without power for four days after a tree fell on the main power lines feeding the site. This was long enough to lose insulating vacuum in the cryomodules and cryogenic systems resulting in the whole accelerator warming up and the total loss of the liquid helium inventory. This thermal cycle stressed many of the cryomodule components causing several cavities to become inoperable due to helium to vacuum leaks. At the same time the thermal cycle released years of adsorbed gas from the cold surfaces. Over the next days and weeks this gas was pumped away, the insulating vacuum was restored and the machine was cooled back down and re-commissioned. In a testament to the robustness of SRF technology, only a small loss in energy capability was apparent, although individual cavities had quite different field-emission characteristics compared to before the event. In Summer 2004 a section of the machine was again cycled to room temperature during the long maint...

  13. SRF Performance of CEBAF After Thermal Cycle to Ambient Temperature

    International Nuclear Information System (INIS)

    Robert Rimmer; Jay Benesch; Joseph Preble; Charles Reece

    2005-01-01

    In September 2003, in the wake of Hurricane Isabel, JLab was without power for four days after a tree fell on the main power lines feeding the site. This was long enough to lose insulating vacuum in the cryomodules and cryogenic systems resulting in the whole accelerator warming up and the total loss of the liquid helium inventory. This thermal cycle stressed many of the cryomodule components causing several cavities to become inoperable due to helium to vacuum leaks. At the same time the thermal cycle released years of adsorbed gas from the cold surfaces. Over the next days and weeks this gas was pumped away, the insulating vacuum was restored and the machine was cooled back down and re-commissioned. In a testament to the robustness of SRF technology, only a small loss in energy capability was apparent, although individual cavities had quite different field-emission characteristics compared to before the event. In Summer 2004 a section of the machine was again cycled to room temperature during the long maintenance shutdown. We report on the overall SRF performance of the machine after these major disturbances and on efforts to characterize and optimize the new behavior for high-energy running

  14. Temperature enhancement of secondary electron emission from hydrogenated diamond films

    International Nuclear Information System (INIS)

    Stacey, A.; Prawer, S.; Rubanov, S.; Akhvlediani, R.; Michaelson, Sh.; Hoffman, A.

    2009-01-01

    The effect of temperature on the stability of the secondary electron emission (SEE) yield from ∼100-nm-thick continuous diamond films is reported. At room temperature, the SEE yield was found to decay as a function of electron irradiation dose. The SEE yield is observed to increase significantly upon heating of the diamond surface. Furthermore, by employing moderate temperatures, the decay of the SEE yield observed at room temperature is inhibited, showing a nearly constant yield with electron dose at 200 deg. C. The results are explained in terms of the temperature dependence of the electron beam-induced hydrogen desorption from the diamond surface and surface band bending. These findings demonstrate that the longevity of diamond films in practical applications of SEE can be increased by moderate heating.

  15. Oxidation of ST55, LH15 and Arema steels at high temperatures in ambient air

    Czech Academy of Sciences Publication Activity Database

    Kučera, Jaroslav; Million, Bořivoj; Adamaszek, K.

    2004-01-01

    Roč. 42, č. 4 (2004), s. 242-250 ISSN 0023-432X Institutional research plan: CEZ:AV0Z2041904 Keywords : high temperatures * oxidation steels * ambient air Subject RIV: JG - Metallurgy Impact factor: 1.056, year: 2004

  16. Growth responses to dietary lysine at high and low ambient temperatures in male turkeys

    NARCIS (Netherlands)

    Veldkamp, T.; Ferket, P.; Kwakkel, R.P.; Kogut, J.; Verstegen, M.W.A.

    2003-01-01

    Several researchers have postulated that dietary lysine requirements for turkeys are dependent upon ambient temperature. To test and quantify this hypothesis, a factorial experiment was designed with four dietary lysine levels (75, 90, 105, and 120% of NRC lysine recommendations) from 1 d of age

  17. Storage of whole blood for up to 24 hours at ambient temperature prior to component preparation

    NARCIS (Netherlands)

    Pietersz, R. N.; de Korte, D.; Reesink, H. W.; Dekker, W. J.; van den Ende, A.; Loos, J. A.

    1989-01-01

    The effect of rapid cooling to 20-24 degrees C of whole blood immediately after collection, using 'cooling units' with butane-1,4-diol and prolonged storage up to 24 h at ambient temperature was investigated in the whole blood and the subsequently prepared plasma, buffy coat and buffy-coat-poor red

  18. The effect of nozzle diameter, injection pressure and ambient temperature on spray characteristics in diesel engine

    Science.gov (United States)

    Rhaodah Andsaler, Adiba; Khalid, Amir; Sharifhatul Adila Abdullah, Nor; Sapit, Azwan; Jaat, Norrizam

    2017-04-01

    Mixture formation of the ignition process is a key element in the diesel combustion as it influences the combustion process and exhaust emission. Aim of this study is to elucidate the effects of nozzle diameter, injection pressure and ambient temperature to the formation of spray. This study investigated diesel formation spray using Computational Fluid Dynamics. Multiphase volume of fluid (VOF) behaviour in the chamber are determined by means of transient simulation, Eulerian of two phases is used for implementation of mixing fuel and air. The detail behaviour of spray droplet diameter, spray penetration and spray breakup length was visualised using the ANSYS 16.1. This simulation was done in different nozzle diameter 0.12 mm and 0.2 mm performed at the ambient temperature 500 K and 700 K with different injection pressure 40 MPa, 70 MPa and 140 MPa. Results show that high pressure influence droplet diameter become smaller and the penetration length longer with the high injection pressure apply. Smaller nozzle diameter gives a shorter length of the breakup. It is necessary for nozzle diameter and ambient temperature condition to improve the formation of spray. High injection pressure is most effective in improvement of formation spray under higher ambient temperature and smaller nozzle diameter.

  19. Selective hydrogen purification through graphdiyne under ambient temperature and pressure

    Science.gov (United States)

    Cranford, Steven W.; Buehler, Markus J.

    2012-07-01

    Graphdiyne, a recently synthesized one-atom-thick carbon allotrope, is atomistically porous - characterized by a regular ``nanomesh'' - and suggests application as a separation membrane for hydrogen purification. Here we report a full atomistic reactive molecular dynamics investigation to determine the selective diffusion properties of hydrogen (H2) amongst carbon monoxide (CO) and methane (CH4), a mixture otherwise known as syngas, a product of the gasification of renewable biomass (such as animal wastes). Under constant temperature simulations, we find the mass flux of hydrogen molecules through a graphdiyne membrane to be on the order of 7 to 10 g cm-2 s-1 (between 300 K and 500 K), with carbon monoxide and methane remaining isolated. Using a simple Arrhenius relation, we determine the energy required for permeation on the order of 0.11 +/- 0.03 eV for single H2 molecules. We find that addition of marginal applied force (approximately 1 to 2 pN per molecule, representing a controlled pressure gradient, ΔP, on the order of 100 to 500 kPa) can successfully enhance the separation of hydrogen gas. Addition of larger driving forces (50 to 100 pN per molecule) is required to selectively filter carbon monoxide or methane, suggesting that, under near-atmospheric conditions, only hydrogen gas will pass such a membrane. Graphdiyne provides a unique, chemically inert and mechanically stable platform facilitating selective gas separation at nominal pressures using a homogeneous material system, without a need for chemical functionalization or the explicit introduction of molecular pores.

  20. Hot dogs: High ambient temperatures impact reproductive success in a tropical carnivore.

    Science.gov (United States)

    Woodroffe, Rosie; Groom, Rosemary; McNutt, J Weldon

    2017-10-01

    Climate change imposes an urgent need to recognise and conserve the species likely to be worst affected. However, while ecologists have mostly explored indirect effects of rising ambient temperatures on temperate and polar species, physiologists have predicted direct impacts on tropical species. The African wild dog (Lycaon pictus), a tropical species, exhibits few of the traits typically used to predict climate change vulnerability. Nevertheless, we predicted that wild dog populations might be sensitive to weather conditions, because the species shows strongly seasonal reproduction across most of its geographical range. We explored associations between weather conditions, reproductive costs, and reproductive success, drawing on long-term wild dog monitoring data from sites in Botswana (20°S, 24 years), Kenya (0°N, 12 years), and Zimbabwe (20°S, 6 years). High ambient temperatures were associated with reduced foraging time, especially during the energetically costly pup-rearing period. Across all three sites, packs which reared pups at high ambient temperatures produced fewer recruits than did those rearing pups in cooler weather; at the non-seasonal Kenya site such packs also had longer inter-birth intervals. Over time, rising ambient temperatures at the (longest-monitored) Botswana site coincided with falling wild dog recruitment. Our findings suggest a direct impact of high ambient temperatures on African wild dog demography, indicating that this species, which is already globally endangered, may be highly vulnerable to climate change. This vulnerability would have been missed by simplistic trait-based assessments, highlighting the limitations of such assessments. Seasonal reproduction, which is less common at low latitudes than at higher latitudes, might be a useful indicator of climate change vulnerability among tropical species. © 2017 The Authors. Journal of Animal Ecology © 2017 British Ecological Society.

  1. 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).

  2. Effects of low ambient temperature on hemodynamics and oxygen dynamics in a porcine hemorrhagic shock model

    Directory of Open Access Journals (Sweden)

    Xue-feng ZHANG

    2013-02-01

    Full Text Available Objective  To investigate the effects of low ambient temperature on hemodynamics and oxygen dynamics in a porcine hemorrhagic shock model. Methods  Thirty-two healthy adult Bama miniature pigs were randomly divided into four groups (8 each: control (group C, shock under room temperature (22℃, group R, shock under low ambient temperature (–10℃, group L and shock under normal body temperature (keep pulmonary arterial temperature ranged from 38.5 to 39.5℃, group N. The hemorrhagic shock model was reproduced by venous bleeding (40% of total blood volume, and the core temperature (pulmonary arterial temperature and rectal temperature, heart rate (HR, mean arterial pressure (MAP, pulmonary arterial pressure (PAP, pulmonary arterial wedge pressure (PAWP, central venous pressure (CVP, cardiac output (CO, hemoglobin (Hb, saturation of mixed venous blood (SvO2 and blood gas analysis were recorded before reproduction of shock and at different time points after hemorrhagic shock. The whole body oxygen delivery index (DO2I, oxygen uptake index (VO2I, and oxygen extraction ratio (O2ER were calculated. Results  Four pigs died in group N during the experiment, meanwhile, no pig died in other groups. The core temperature in group C, R and L decreased significantly compared with group N (P<0.05, and the core temperature in group L was significantly lower than that in groups C and R from 120 minutes after shock. No difference was found in hemodynamics, oxygen dynamics and prognosis between group R and group L. The HR and VO2I in group N were significantly higher than those in group L and group R, while there was no difference in other indices between the 3 groups. Conclusion  The hemodynamics and oxygen dynamics indices don't worsen in hemorrhagic shock pigs under low ambient temperature, possibly resulting from induced hypothermia caused by anesthesia.

  3. Environmental ambient temperature and blood pressure in adults: A systematic review and meta-analysis.

    Science.gov (United States)

    Wang, Qiong; Li, Changchang; Guo, Yanfang; Barnett, Adrian G; Tong, Shilu; Phung, Dung; Chu, Cordia; Dear, Keith; Wang, Xuemei; Huang, Cunrui

    2017-01-01

    Although many individual studies have examined the association between temperature and blood pressure (BP), they used different methods and also their results were somewhat inconsistent. The aims of this study are to quantitatively summarize previous studies and to systematically assess the methodological issues to make recommendations for future research. We searched relevant empirical studies published before January 2016 concerning temperature and BP among adults using the MEDLINE, Embase and PubMed databases. Mean changes in systolic (SBP) and diastolic blood pressure (DBP) per 1°C reduction in temperature were pooled using a random-effects meta-analysis. Of 23 studies included, 14 were used for meta-analysis. Consistent, statistically significant, inverse associations were observed between ambient temperature (mean, maximum, minimum outdoor temperature and indoor temperature) and BP. An 1°C decrease in mean daily outdoor temperature was associated with an increase in SBP and DBP of 0.26mmHg (95% CI: 0.18-0.33) and 0.13 (95% CI: 0.11-0.16), respectively. The increase was greater in people with conditions related to cardiovascular disease. An 1°C decrease in indoor temperature was associated with 0.38mmHg (0.18-0.58) increase in SBP, while the effects on DBP were not estimated due to limited studies. Among the previous studies on temperature-BP relationship, temperature and BP measurements are not accurate enough and statistical methods need to be improved. Lower ambient temperatures seem to increase adults' BP and people with conditions related to cardiovascular disease are more susceptible to drops in temperature. Indoor temperature appeared to have a stronger effect on BP than outdoor temperature. To understand temperature-BP relationship well, a study combining repeated personal temperature exposure and ambulatory BP monitoring, applying improved statistical methods to examine potential non-linear relationship is warranted. Copyright © 2016 Elsevier B

  4. The monitoring and fatigue behavior of CFCCs at ambient temperature and 1000 degrees C

    International Nuclear Information System (INIS)

    Miriyala, N.; Liaw, P.K.; McHargue, C.J.

    1997-01-01

    Metallographically polished flexure bars of Nicalon/SiC and Nicalon/alumina composites were subjected to monotonic and cycle-fatigue loadings, with loading either parallel or normal to the fabric plies. The fabric orientation did not significantly affect the mechanical behavior of the Nicalon/SiC composite at ambient temperature. However, the mechanical behavior of the Nicalon/alumina composite was significantly affected by the fabric orientation at ambient temperature in air and at 1000 degrees C in argon atmosphere. In addition, there was a significant degradation in the fatigue performance of the alumina matrix composite at the elevated temperature, owing to creep in the material and degradation in the fiber strength

  5. Influence of ambient temperatures on performance of a CO2 heat pump water heating system

    International Nuclear Information System (INIS)

    Yokoyama, Ryohei; Shimizu, Takeshi; Ito, Koichi; Takemura, Kazuhisa

    2007-01-01

    In residential applications, an air-to-water CO 2 heat pump is used in combination with a domestic hot water storage tank, and the performance of this system is affected significantly not only by instantaneous ambient air and city water temperatures but also by hourly changes of domestic hot water consumption and temperature distribution in the storage tank. In this paper, the performance of a CO 2 heat pump water heating system is analyzed by numerical simulation. A simulation model is created based on thermodynamic equations, and the values of model parameters are estimated based on measured data for existing devices. The calculated performance is compared with the measured one, and the simulation model is validated. The system performance is clarified in consideration of seasonal changes of ambient air and city water temperatures

  6. Adaptation of root growth to increased ambient temperature requires auxin and ethylene coordination in Arabidopsis

    DEFF Research Database (Denmark)

    Fei, Qionghui; Wei, Shaodong; Zhou, Zhaoyang

    2017-01-01

    Key message: A fresh look at the roles of auxin, ethylene, and polar auxin transport during the plant root growth response to warmer ambient temperature (AT). Abstract: The ambient temperature (AT) affects plant growth and development. Plants can sense changes in the AT, but how this change......-naphthaleneacetic acid, but not indole-3-acetic acid (IAA). AUX1, PIN1, and PIN2 are involved in the ckrc1-1 root gravity response under increased AT. Furthermore, CKRC1-dependent auxin biosynthesis was critical for maintaining PIN1, PIN2, and AUX1 expression at elevated temperatures. Ethylene was also involved...... in this regulation through the ETR1 pathway. Higher AT can promote CKRC1-dependent auxin biosynthesis by enhancing ETR1-mediated ethylene signaling. Our research suggested that the interaction between auxin and ethylene and that the interaction-mediated polar auxin transport play important roles during the plant...

  7. Combined Effect of Ambient Temperature with Radiofrequency Electromagnetic Radiation in Rabbit

    International Nuclear Information System (INIS)

    Kim, Jin Kyu; Choi, Dae Seong; Komarova, Ludmila N.; Petin, Vladislav G.

    2010-01-01

    There has been an increasing interest in synergistic effects observed after combined action of various agents. Many studies have shown that numerous physical and chemical agents combined with hyperthermia can interact in a synergistic manner when the effect produced by both agents used in combination exceeded the expected results from simple summation of the every effect produced by heat and the particular agent. I t was found that ambient temperature had a profound effect on the thermoregulatory responses to radiofrequency electromagnetic radiation (RFR) in various animals and humans. An extensive quantitative investigation of synergistic interaction of ambient temperature and microwaves has been published for rabbit heating. I t would be of interest to estimate whether or not the general features of the combined action revealed with unicellular organisms can be expressed for animals exposed to microwave power combined with a higher environmental temperature.

  8. 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.

  9. Modeling Temperature Development of Li-Ion Battery Packs in Hybrid Refuse Truck Operating at Different Ambient Conditions

    DEFF Research Database (Denmark)

    Coman, Paul Tiberiu; Veje, Christian

    2014-01-01

    This paper presents a dynamic model for simulating the heat dissipation and the impact of Phase Change Materials (PCMs) on the peak temperature in Lithium-ion batteries during discharging operation of a hybrid truck under different ambient temperatures.......This paper presents a dynamic model for simulating the heat dissipation and the impact of Phase Change Materials (PCMs) on the peak temperature in Lithium-ion batteries during discharging operation of a hybrid truck under different ambient temperatures....

  10. Multi-spectral pyrometer for narrow space with high ambient temperature

    Science.gov (United States)

    Gao, Shan; Wang, Lixin; Feng, Chi; Xiao, Yihan; Daniel, Ketui

    2015-08-01

    A fiber-optic multi-spectral pyrometer with high spatial and temporal resolution has been applied to measure temperatures of the range from 700 to 1200 K. In a narrow space, the important problems in temperature measurement include the unknown emissivity on target surface and the thermal radiation from the high ambient temperature. This paper analyzed several critical issues affecting the multi-spectral pyrometer and calculated the corresponding model through genetic algorithm. The experiment result showed that this method has high accuracy and the measurement error is 0.44 %.

  11. To flower or not to flower, a temperature-sensitive decision. Characterization of flowering responses at high ambient temperature in Arabidopsis thaliana

    NARCIS (Netherlands)

    Rodenburg, N.

    2015-01-01

    To maximize fitness, plants use environmental cues to optimize growth processes. One of the processes under strong environmental regulation is flowering. Multiple environmental factors influence flowering, including temperature. Both a continuously increased ambient temperature as well as temporary

  12. To flower or not to flower, a temperature-sensitive decision : Characterization of flowering responses at high ambient temperature in Arabidopsis thaliana

    NARCIS (Netherlands)

    Rodenburg, Nicole

    2015-01-01

    To maximize fitness, plants use environmental cues to optimize growth processes. One of the processes under strong environmental regulation is flowering. Multiple environmental factors influence flowering, including temperature. Both a continuously increased ambient temperature as well as temporary

  13. Live pups from evaporatively dried mouse sperm stored at ambient temperature for up to 2 years.

    Directory of Open Access Journals (Sweden)

    Jie Liu

    Full Text Available The purpose of this study is to develop a mouse sperm preservation method based on evaporative drying. Mouse sperm were evaporatively dried and stored at 4°C and ambient temperature for 3 months to 2 years. Upon rehydration, a single sperm was injected into a mature oocyte to develop into a blastocyst after culture or a live birth after embryo transfer to a recipient female. For the samples stored at 4°C for 3, 6, 12, 18, and 24 months, the blastocyst formation rate was 61.5%, 49.1%, 31.5%, 32.2%, and 41.4%, respectively. The blastocyst rate for those stored at ambient temperature (∼22°C for 3, 6, 12, and 18 months was 57.8%, 36.2%, 33.6%, and 34.4%, respectively. Fifteen, eight and three live pups were produced from sperm stored at room temperature for 12, 18, and 24 months, respectively. This is the first report of live offspring produced from dried mouse sperm stored at ambient temperature for up to 2 years. Based on these results, we suggest that evaporative drying is a potentially useful method for the routine preservation of mouse sperm.

  14. Influence of Ambient Temperature and Confinement on the Chemical Immobilization of Fallow Deer ( Dama dama ).

    Science.gov (United States)

    Costa, Giovanna Lucrezia; Nastasi, Bernadette; Musicò, Marcello; Spadola, Filippo; Morici, Manuel; Cucinotta, Giuseppe; Interlandi, Claudia

    2017-04-01

    We used physiological parameters and the duration and quality of anesthesia to compare the effects of two ambient temperatures and of the duration of pre-immobilization confinement on the chemical immobilization of fallow deer. We divided 45 free-ranging fallow deer ( Dama dama ) into two groups: Group A were deer captured in winter (average 12 C), using 1 mg/kg of xylazine and 1 mg/kg of tiletamine-zolazepam; and Group B were deer captured in spring (average 24 C), using 2 mg/kg of xylazine and 1.5 mg/kg of tiletamine-zolazepam, after being confined in a pen. We observed lower mean respiratory rate and oxygen saturation in Group B. In contrast, the mean body temperature and the mean blood lactate concentration were significantly higher in Group B, and quality of anesthesia was better in Group A. Mean induction time (time to achieve recumbency) and durations of recumbency were the same in Groups A and B: approximately 8 and 50 min, respectively. Despite the lower drug dosage, better sedation was obtained in Group A than in group B. The time of year, most likely associated with differences in ambient temperature and in confinement, influenced the recommended dosage for xylazine and tiletamine-zolazepam in fallow deer. As all the animals were sound, we concluded that the only factors that influenced the outcome of the present study were the ambient temperature and the level of stress caused by confinement in the pen.

  15. Analyzing the Impact of Ambient Temperature Indicators on Transformer Life in Different Regions of Chinese Mainland

    Science.gov (United States)

    Bai, Cui-fen; Gao, Wen-Sheng; Liu, Tong

    2013-01-01

    Regression analysis is applied to quantitatively analyze the impact of different ambient temperature characteristics on the transformer life at different locations of Chinese mainland. 200 typical locations in Chinese mainland are selected for the study. They are specially divided into six regions so that the subsequent analysis can be done in a regional context. For each region, the local historical ambient temperature and load data are provided as inputs variables of the life consumption model in IEEE Std. C57.91-1995 to estimate the transformer life at every location. Five ambient temperature indicators related to the transformer life are involved into the partial least squares regression to describe their impact on the transformer life. According to a contribution measurement criterion of partial least squares regression, three indicators are conclusively found to be the most important factors influencing the transformer life, and an explicit expression is provided to describe the relationship between the indicators and the transformer life for every region. The analysis result is applicable to the area where the temperature characteristics are similar to Chinese mainland, and the expressions obtained can be applied to the other locations that are not included in this paper if these three indicators are known. PMID:23843729

  16. Influence of ambient temperature and minute ventilation on passive and active heat and moisture exchangers.

    Science.gov (United States)

    Lellouche, François; Qader, Siham; Taillé, Solenne; Lyazidi, Aissam; Brochard, Laurent

    2014-05-01

    During invasive mechanical ventilation, inspired gases must be humidified. We previously showed that high ambient temperature greatly impaired the hygrometric performance of heated wire-heated humidifiers. The aim of this bench and clinical study was to assess the humidification performance of passive and active heat and moisture exchangers (HMEs) and the impact of ambient temperature and ventilator settings. We first tested on the bench a device with passive and active humidification properties (Humid-Heat, Teleflex), and 2 passive hydrophobic/hygroscopic HMEs (Hygrobac and Hygrobac S, Tyco Healthcare). The devices were tested at 3 different ambient temperatures (from 22 to 30 °C), and at 2 minute ventilation settings (10 and 20 L/min). Inspired gas hygrometry was measured at the Y-piece with the psychrometric method. In addition to the bench study, we measured the hygrometry of inspired gases in 2 different clinical studies. In 15 mechanically ventilated patients, we evaluated Humid-Heat at different settings. Additionally, we evaluated Humid-Heat and compared it with Hygrobac in a crossover study in 10 patients. On the bench, with the Hygrobac and Hygrobac S the inspired absolute humidity was ∼ 30 mg H2O/L, and with the Humid-Heat, slightly Heat provided inspired humidity in a range from 28.5 to 42.0 mg H2O/L, depending on settings, and was only weakly influenced by the patient's body temperature. In this study both passive and active HMEs had stable humidification performance with negligible influence of ambient temperature and minute ventilation. This contrasts with previous findings with heated wire-heated humidifiers. Although there are no clear data demonstrating that higher humidification impacts outcomes, it is worth noting that humidity was significantly higher with the active HME.

  17. Apoptotic responses of zebrafish (Danio rerio) after exposure with microcystin-LR under different ambient temperatures.

    Science.gov (United States)

    Ji, Wei; Liang, Hualei; Zhou, Wenshan; Zhang, Xuezhen

    2013-08-01

    Microcystins (MCs) can cause evident hepatic apoptosis. In vitro studies indicated that uptake of MC by isolated hepatocytes was dramatically reduced as ambient temperature dropped, and some studies presented a hypothesis that differences in core body temperatures in animals result in diverse uptake of MC, as well as different toxic effects. Thus far, however, few in vivo studies have been conducted to investigate the effects of temperature on MC-induced hepatocyte apoptosis in fish, a typical poikilotherm. In the present study, zebrafish were treated with MC-LR, an MC metabolite, at three water temperatures (12, 22 and 32 °C), and evident differences in apoptotic profiles were observed. Damage to liver ultrastructures revealed temperature-dependent early-stage patterns of apoptosis. Flow-cytometric analysis indicated that hepatocyte apoptotic rates varied with a temperature-dependent effect. The transcription levels of some apoptosis-related genes were determined using quantitative real-time polymerase chain reaction, and significantly elevated gene expressions of P53, Bcl-2, Bax and caspase-3 were found in the 12 and 32 °C groups. Results of the present study indicate that different ambient temperatures can lead to various toxic effects of MCs on hepatic apoptosis in fish. Copyright © 2012 John Wiley & Sons, Ltd.

  18. Influence of Physical Activity and Ambient Temperature on Hydration: The European Hydration Research Study (EHRS)

    Science.gov (United States)

    Mora-Rodriguez, Ricardo; Ortega, Juan F.; Fernandez-Elias, Valentin E.; Kapsokefalou, Maria; Malisova, Olga; Athanasatou, Adelais; Husemann, Marlien; Domnik, Kirsten; Braun, Hans

    2016-01-01

    This study explored the effects of physical activity (PA) and ambient temperature on water turnover and hydration status. Five-hundred seventy three healthy men and women (aged 20–60 years) from Spain, Greece and Germany self-reported PA, registered all food and beverage intake, and collected 24-h urine during seven consecutive days. Fasting blood samples were collected at the onset and end of the study. Food moisture was assessed using nutritional software to account for all water intake which was subtracted from daily urine volume to allow calculation of non-renal water loss (i.e., mostly sweating). Hydration status was assessed by urine and blood osmolality. A negative association was seen between ambient temperature and PA (r = −0.277; p hydration status (i.e., lower urine and blood osmolality). PMID:27128938

  19. Evaluation of Aluminum Alloy 2050-T84 Microstructure and Mechanical Properties at Ambient and Cryogenic Temperatures

    Science.gov (United States)

    Hafley, Robert A.; Domack, Marcia S.; Hales, Stephen J.; Shenoy, Ravi N.

    2011-01-01

    Aluminum alloy 2050 is being considered for the fabrication of cryogenic propellant tanks to reduce the mass of future heavy-lift launch vehicles. The alloy is available in section thicknesses greater than that of the incumbent aluminum alloy, 2195, which will enable designs with greater structural efficiency. While ambient temperature design allowable properties are available for alloy 2050, cryogenic properties are not available. To determine its suitability for use in cryogenic propellant tanks, tensile, compression and fracture tests were conducted on 4 inch thick 2050-T84 plate at ambient temperature and at -320degF. Various metallurgical analyses were also performed in order to provide an understanding of the compositional homogeneity and microstructure of 2050.

  20. Psychophysics of a nociceptive test in the mouse: ambient temperature as a key factor for variation.

    Directory of Open Access Journals (Sweden)

    Ivanne Pincedé

    Full Text Available The mouse is increasingly used in biomedical research, notably in behavioral neurosciences for the development of tests or models of pain. Our goal was to provide the scientific community with an outstanding tool that allows the determination of psychophysical descriptors of a nociceptive reaction, which are inaccessible with conventional methods: namely the true threshold, true latency, conduction velocity of the peripheral fibers that trigger the response and latency of the central decision-making process.Basically, the procedures involved heating of the tail with a CO(2 laser, recording of tail temperature with an infrared camera and stopping the heating when the animal reacted. The method is based mainly on the measurement of three observable variables, namely the initial temperature, the heating rate and the temperature reached at the actual moment of the reaction following random variations in noxious radiant heat. The initial temperature of the tail, which itself depends on the ambient temperature, very markedly influenced the behavioral threshold, the behavioral latency and the conduction velocity of the peripheral fibers but not the latency of the central decision-making.We have validated a psychophysical approach to nociceptive reactions for the mouse, which has already been described for rats and Humans. It enables the determination of four variables, which contribute to the overall latency of the response. The usefulness of such an approach was demonstrated by providing new fundamental findings regarding the influence of ambient temperature on nociceptive processes. We conclude by challenging the validity of using as "pain index" the reaction time of a behavioral response to an increasing heat stimulus and emphasize the need for a very careful control of the ambient temperature, as a prevailing environmental source of variation, during any behavioral testing of mice.

  1. Ambient air pollution, temperature and out-of-hospital coronary deaths in Shanghai, China

    International Nuclear Information System (INIS)

    Dai, Jinping; Chen, Renjie; Meng, Xia; Yang, Changyuan; Zhao, Zhuohui; Kan, Haidong

    2015-01-01

    Few studies have evaluated the effects of ambient air pollution and temperature in triggering out-of-hospital coronary deaths (OHCDs) in China. We evaluated the associations of air pollution and temperature with daily OHCDs in Shanghai, China from 2006 to 2011. We applied an over-dispersed generalized additive model and a distributed lag nonlinear model to analyze the effects of air pollution and temperature, respectively. A 10 μg/m 3 increase in the present-day PM 10 , PM 2.5 , SO 2 , NO 2 and CO were associated with increases in OHCD mortality of 0.49%, 0.68%, 0.88%, 1.60% and 0.08%, respectively. A 1 °C decrease below the minimum-mortality temperature corresponded to a 3.81% increase in OHCD mortality on lags days 0–21, and a 1 °C increase above minimum-mortality temperature corresponded to a 4.61% increase over lag days 0–3. No effects were found for in-hospital coronary deaths. This analysis suggests that air pollution, low temperature and high temperature may increase the risk of OHCDs. - Highlights: • Few studies have evaluated the effects of air pollution and temperature on OHCDs in China. • The present-day concentrations of air pollution were associated with OHCDs. • The effect of high temperatures on OHCDs was more immediate than low temperatures. • No significant effects were found for in-hospital coronary deaths. - Ambient air pollution and temperature may trigger out-of-hospital coronary deaths but not in-hospital coronary deaths

  2. Comprehensive particle characterization of modern gasoline and diesel passenger cars at low ambient temperatures

    Science.gov (United States)

    Mathis, Urs; Mohr, Martin; Forss, Anna-Maria

    Particle measurements were performed in the exhaust of five light-duty vehicles (Euro-3) at +23, -7, and -20 °C ambient temperatures. The characterization included measurements of particle number, active surface area, number size distribution, and mass size distribution. We investigated two port-injection spark-ignition (PISI) vehicles, a direct-injection spark-ignition (DISI) vehicle, a compressed ignition (CI) vehicle with diesel particle filter (DPF), and a CI vehicle without DPF. To minimize sampling effects, particles were directly sampled from the tailpipe with a novel porous tube diluter at controlled sampling parameters. The diluted exhaust was split into two branches to measure either all or only non-volatile particles. Effect of ambient temperature was investigated on particle emission for cold and warmed-up engine. For the gasoline vehicles and the CI vehicle with DPF, the main portion of particle emission was found in the first minutes of the driving cycle at cold engine start. The particle emission of the CI vehicle without DPF was hardly affected by cold engine start. For the PISI vehicles, particle number emissions were superproportionally increased in the diameter size range from 0.1 to 0.3 μm during cold start at low ambient temperature. Based on the particle mass size distribution, the DPF removed smaller particles ( dp0.5μm). No significant effect of ambient temperature was observed when the engine was warmed up. Peak emission of volatile nanoparticles only took place at specific conditions and was poorly repeatable. Nucleation of particles was predominately observed during or after strong acceleration at high speed and during regeneration of the DPF.

  3. Deriving Deep Ocean Temperature Changes From the Ambient Acoustic Noise Field

    Science.gov (United States)

    Sambell, K.; Evers, L. G.; Snellen, M.

    2016-12-01

    Passively deriving the deep ocean temperature is a challenge. However, knowledge about changes in the deep ocean temperature are important in relation to climate change. In-situ observations are are and satellite observations are hardly applicable. Low-frequency sound waves of a few hertz can penetrate the deep oceans over long distances. As their propagation is temperature dependent, these waves contain valuable information that can be used for temperature monitoring. In this study, the use of interferometry is demonstrated by applying this technique to ambient noise measured at two hydrophone arrays located near Robinson Crusoe Island in the South Pacific Ocean. The arrays are separated by 40 km and are located at a depth of 800 m. Both arrays consist of three hydrophones with an interstation distance of 2 km. It is shown that the acoustic velocity, and with this the temperature variation, can be derived from measured hydro-acoustic data. Furthermore, the findings are supported by ocean models that describe the propagation of sound between the hydrophone arrays. This study shows the potential of using the ambient noise field for temperature monitoring in the deep ocean.

  4. Effect of high ambient temperature on behavior of sheep under semi-arid tropical environment

    Science.gov (United States)

    De, Kalyan; Kumar, Davendra; Saxena, Vijay Kumar; Thirumurugan, Palanisamy; Naqvi, Syed Mohammed Khursheed

    2017-07-01

    High environmental temperature is a major constraint in sheep production under semi-arid tropical environment. Behavior is the earliest indicator of animal's adaptation and responses to the environmental alteration. Therefore, the objective of this study was to assess the effects of high ambient temperature on the behavior of sheep under a semi-arid tropical environment. The experiment was conducted for 6 weeks on 16 Malpura cross (Garole × Malpura × Malpura (GMM)) rams. The rams were divided equally into two groups, designated as C and T. The rams of C were kept in comfortable environmental conditions served as control. The rams of T were exposed to a different temperature at different hours of the day in a climatic chamber, to simulate a high environmental temperature of summer in semi-arid tropic. The behavioral observations were taken by direct instantaneous observation at 15-min intervals for each animal individually. The feeding, ruminating, standing, and lying behaviors were recorded twice a week from morning (0800 hours) to afternoon (1700 hours) for 6 weeks. Exposure of rams to high temperature (T) significantly ( P sheep to high ambient temperature severely modulates the behavior of sheep which is directed to circumvent the effect of the stressor.

  5. Temperature Effects on Mechanical Properties of Woven Thermoplastic Composites for Secondary Aircraft Structure Applications

    Directory of Open Access Journals (Sweden)

    Wang Yue

    2017-01-01

    Full Text Available The effect of temperature on the mechanical behavior of 8-H satin woven glass fabric/polyethylene sulfide (GF/PPS was investigated in this paper. Static-tensile tests were both conducted on notched and unnotched specimens at typical temperatures (ambient, 95°C and 125°C based on the glass transition temperatures (Tg of the neat resin and composite, their strength and moduli were obtained and compared. The damage patterns of failed specimens of notched and unnotched were examined with the aid of high-definition camera and stereomicroscope. The results of stress-strain relationships showed that the slight nonlinearity of the curves were observed for these two specimens, which was associated with the plastic deformation of localized resin. The damage patterns of notched and unnotched specimens at different temperatures proved that damage and plastic deformation were two simultaneous mechanisms and it was prominent in the notched. It was the overstress accommodation mechanism that led to a relative high strength rentention for the notched and a reduction of the hole sensitivity. The results obtained in this paper indicated that GF/PPS can be used as secondary aircraft structures at elevated temperatures higher than its Tg.

  6. Stabilization of some vegetable oils by sugarcane leaf extract at ambient temperature

    International Nuclear Information System (INIS)

    Nadeem, M.; Azeem, M.W.

    2016-01-01

    The present was aimed to assess the antioxidant of ethanolic sugarcane leaf extract for the stabilisation of sunflower, (SFO), soybean and (SBO) canola oils (CO) at ambient temperature. SFO, SBO and CO were added with 600 ppm sugracane leaf extract, fielled in transparent PET bottles, stored at ambient temperature for 180 days, sampled at 0, 60, 120 and 180 days for the assessment of oxidative stability. Total phenolic content in sugracane leaf extract (SLE) was 724.3 (mg GAE/100g). 2,2, Diphenyl-2 picrylhydrazyl free radical scavenging activity of slewas 76% as compared to 88% butylated hydroxyl toluene. C18:1 in fresh, 6 months stored controls and SLE supplemented SFO were 46.12%, 42.59% and 47.15%, 40.29, 43.13%, respectively. C18:2 and 18.3 in fresh and 180 days stored control and SLE suplemented SBO were 51.19%, 45.61%, 48.97% and 6.19%, 3.37% and 5.67%, respectively. Similar trend was also recorded and canola oil. Induction period of supplemented vegetable oil was higher than the un-supplemented sample. Sensory characteristics of SLE supplemented vegetable oil were not different from the control. Sugarcane leaf extract can be used for the long term preservation of SFO, SBO and CO at ambient temperature. (author)

  7. Dynamics of antibiotic resistance genes and presence of putative pathogens during ambient temperature anaerobic digestion.

    Science.gov (United States)

    Resende, J A; Diniz, C G; Silva, V L; Otenio, M H; Bonnafous, A; Arcuri, P B; Godon, J-J

    2014-12-01

    This study was focused on evaluating the persistency of antimicrobial resistance (AR) genes and putative pathogenic bacteria in an anaerobic digesters operating at mesophilic ambient temperature, in two different year seasons: summer and winter. Abundance and dynamic of AR genes encoding resistance to macrolides (ermB), aminoglycosides (aphA2) and beta-lactams (blaTEM -1 ) and persistency of potentially pathogenic bacteria in pilot-scale anaerobic digesters were investigated. AR genes were determined in the influent and effluent in both conditions. Overall, after 60 days, reduction was observed for all evaluated genes. However, during the summer, anaerobic digestion was more related to the gene reduction as compared to winter. Persistency of potentially pathogenic bacteria was also evaluated by metagenomic analyses compared to an in-house created database. Clostridium, Acinetobacter and Stenotrophomonas were the most identified. Overall, considering the mesophilic ambient temperature during anaerobic digestion (summer and winter), a decrease in pathogenic bacteria detection through metagenomic analysis and AR genes is reported. Although the mesophilic anaerobic digestion has been efficient, the results may suggest medically important bacteria and AR genes persistency during the process. This is the first report to show AR gene dynamics and persistency of potentially pathogenic bacteria through metagenomic approach in cattle manure ambient temperature anaerobic digestion. © 2014 The Society for Applied Microbiology.

  8. Lithium doping on covalent organic framework-320 for enhancing hydrogen storage at ambient temperature

    International Nuclear Information System (INIS)

    Xia, Liangzhi; Liu, Qing

    2016-01-01

    Density Functional Theory (DFT) combines with grand canonical Monte Carlo (GCMC) simulations are performed to explore the effect of Li doping on the hydrogen storage capability of COF-320. The results show that the interaction energy between the H 2 and the Li-doped COF-320 is about three times higher than that of pristine COF-320. GCMC simulations are employed to study the hydrogen uptake of Li-doped COF-320 at ambient temperature, further confirm that the lithium doping can improve the hydrogen uptake at ambient temperature. Our results demonstrate that Li-doped COFs have good potential in the field of hydrogen storage. - Graphical abstract: Fig. 1. The optimized cluster model used here to represent the COF-320 and possible adsorption sites (A, B, C) for adsorption of metals in the COF-320. The dangling bonds are terminated by H atoms. C, H, and N atoms are shown as gray, white, and blue colors, respectively. Fig. 2. The adsorption isotherm of H 2 in the pristine and Li-doped COF-320 at 298 K. - Highlights: • The binding sites of single and two lithium atoms in COF-320 were studied. • The interaction energy between the H 2 and the Li-doped COF-320 is about three times higher than that of pristine COF-320. • H 2 uptakes on the Li-doped COFs obtain significant improvement at ambient temperature. • Lithium-doping is a successful strategy for improving hydrogen uptake.

  9. No effect of caffeine on exercise performance in high ambient temperature.

    Science.gov (United States)

    Roelands, Bart; Buyse, Luk; Pauwels, Frank; Delbeke, Frans; Deventer, Koen; Meeusen, Romain

    2011-12-01

    Caffeine, an adenosine receptor antagonist, has shown to improve performance in normal ambient temperature, presumably via an effect on dopaminergic neurotransmission through the antagonism of adenosine receptors. However, there is very limited evidence from studies that administered caffeine and examined its effects on exercise in the heat. Therefore, we wanted to study the effects of caffeine on performance and thermoregulation in high ambient temperature. Eight healthy trained male cyclists completed two experimental trials (in 30°C) in a double-blind-randomized crossover design. Subjects ingested either placebo (6 mg/kg) or caffeine (6 mg/kg) 1 h prior to exercise. Subjects cycled for 60 min at 55% W (max), immediately followed by a time trial to measure performance. The significance level was set at p Caffeine did not change performance (p = 0.462). Rectal temperature was significantly elevated after caffeine administration (p Caffeine significantly increased B-endorphin plasma concentrations at the end of the time trial (p = 0.032). The present study showed no ergogenic effect of caffeine when administered 1 h before exercise in 30°C. This confirms results from a previous study that examined the effects of caffeine administration on a short (15 min) time trial in 40°C. However, caffeine increased core temperature during exercise. Presumably, the rate of increase in core temperature may have counteracted the ergogenic effects of caffeine. However, other factors such as interindividual differences in response to caffeine and changes in neurotransmitter concentrations might also be responsible for the lack of performance improvement of caffeine in high ambient temperature.

  10. Multiplexing milli-volt transmitter for operation in high ambient temperatures

    International Nuclear Information System (INIS)

    Phillips, G.J.

    1980-01-01

    A high integrity method of multiplexing up to two hundred and fifty millivolt level signals and transmitting the data to a remote measuring station via a 12 core flexible cable is described. The system was designed for operation in the normally hazardous and therefore inaccessible areas where high ambient temperatures are experienced. Additionally, because one potential application is in nuclear reactor systems, the design is tolerant to high levels of gamma background. The system's high reliability, high integrity and relatively small and conventional cable installation, makes it applicable to situations which depend upon temperature measurement for plant or personnel safety. (author)

  11. The association between ambient temperature and childhood asthma: a systematic review

    Science.gov (United States)

    Xu, Zhiwei; Crooks, James Lewis; Davies, Janet Mary; Khan, Al Fazal; Hu, Wenbiao; Tong, Shilu

    2017-10-01

    The objectives of this study are to review available information on the association between ambient temperature and childhood asthma, and to elucidate the possible underlying mechanisms of this relationship. A systematic review was conducted based on the papers retrieved from four databases, including PubMed, ProQuest, ScienceDirect, and Scopus. Papers examining the association of absolute temperature or temperature variation with childhood asthma published from 1 January 2000 to 31 December 2016 were included. Thirteen papers have quantified the effect of absolute temperature on childhood asthma, and six papers have examined the effect of intra- or inter-day temperature variation on childhood asthma. All studies were conducted in urban areas. Aeroallergen sensitizations were only considered in the analyses of one study. Discrepancy existed in the significance of the relationship between absolute temperature and childhood asthma, and also in the shape of this relationship (i.e. linear or non-linear) and whether temperature effects were lagged. Increasing evidence is suggesting non-linear relationship between absolute temperature and childhood asthma. Future research should investigate the burden of childhood asthma specifically attributable to extreme temperatures and temperature variation using advanced statistical approach, particularly in rural areas, after properly considering aeroallergens and air pollution. Projecting future burden of childhood asthma under climate change scenarios is also warranted.

  12. The association between ambient temperature and childhood asthma: a systematic review

    Science.gov (United States)

    Xu, Zhiwei; Crooks, James Lewis; Davies, Janet Mary; Khan, Al Fazal; Hu, Wenbiao; Tong, Shilu

    2018-03-01

    The objectives of this study are to review available information on the association between ambient temperature and childhood asthma, and to elucidate the possible underlying mechanisms of this relationship. A systematic review was conducted based on the papers retrieved from four databases, including PubMed, ProQuest, ScienceDirect, and Scopus. Papers examining the association of absolute temperature or temperature variation with childhood asthma published from 1 January 2000 to 31 December 2016 were included. Thirteen papers have quantified the effect of absolute temperature on childhood asthma, and six papers have examined the effect of intra- or inter-day temperature variation on childhood asthma. All studies were conducted in urban areas. Aeroallergen sensitizations were only considered in the analyses of one study. Discrepancy existed in the significance of the relationship between absolute temperature and childhood asthma, and also in the shape of this relationship (i.e. linear or non-linear) and whether temperature effects were lagged. Increasing evidence is suggesting non-linear relationship between absolute temperature and childhood asthma. Future research should investigate the burden of childhood asthma specifically attributable to extreme temperatures and temperature variation using advanced statistical approach, particularly in rural areas, after properly considering aeroallergens and air pollution. Projecting future burden of childhood asthma under climate change scenarios is also warranted.

  13. 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 temperature affected thermoregulation in Group GA.

  14. Is ambient temperature associated with risk of infant mortality? A multi-city study in Korea.

    Science.gov (United States)

    Son, Ji-Young; Lee, Jong-Tae; Bell, Michelle L

    2017-10-01

    Although numerous studies have shown increased risk of mortality from elevated temperatures for adults, limited studies have examined temperature's effect on mortality for infants. Our study investigated the city-specific and overall effects of ambient temperature on infant mortality in seven major cities in Korea, 2004-2007. Birth cohort using a linked birth and death records included 777,570 births with 557 all-cause deaths. We estimated city-specific hazard ratios for each city using an extended Cox proportional hazards model with time-dependent covariates. Then we combined city-specific hazard ratios to generate overall hazard ratio across the seven cities using a Bayesian hierarchical model. Stratified analyses were conducted by cause of death (total and SIDS), exposure period (whole gestation, each trimester, lifetime, 1 month before death, and 2 weeks before death), sex, and maternal characteristics. Overall across the cities, we found significantly positive associations between ambient temperature during 1 month before death or 2 weeks before death and infant mortality from total or SIDS. The overall hazard ratio of infant mortality from total deaths and SIDS for a 1°C increase during 1 month before death was 1.52 (95% CI, 1.46-1.57) and 1.50 (95% CI, 1.35-1.66), respectively. We also found suggestive evidence that some factors such as mother's age may modify the association. Our findings have implications for establishment of policy to reduce the risk of infant mortality from high ambient temperature under climate change. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. High DNA stability in white blood cells and buffy coat lysates stored at ambient temperature under anoxic and anhydrous atmosphere.

    Directory of Open Access Journals (Sweden)

    Anne-Lise Fabre

    Full Text Available Conventional storage of blood-derived fractions relies on cold. However, lately, ambient temperature preservation has been evaluated by several independent institutions that see economic and logistic advantages in getting rid of the cold chain. Here we validated a novel procedure for ambient temperature preservation of DNA in white blood cell and buffy coat lysates based on the confinement of the desiccated biospecimens under anoxic and anhydrous atmosphere in original hermetic minicapsules. For this validation we stored encapsulated samples either at ambient temperature or at several elevated temperatures to accelerate aging. We found that DNA extracted from stored samples was of good quality with a yield of extraction as expected. Degradation rates were estimated from the average fragment size of denatured DNA run on agarose gels and from qPCR reactions. At ambient temperature, these rates were too low to be measured but the degradation rate dependence on temperature followed Arrhenius' law, making it possible to extrapolate degradation rates at 25°C. According to these values, the DNA stored in the encapsulated blood products would remain larger than 20 kb after one century at ambient temperature. At last, qPCR experiments demonstrated the compatibility of extracted DNA with routine DNA downstream analyses. Altogether, these results showed that this novel storage method provides an adequate environment for ambient temperature long term storage of high molecular weight DNA in dehydrated lysates of white blood cells and buffy coats.

  16. High DNA stability in white blood cells and buffy coat lysates stored at ambient temperature under anoxic and anhydrous atmosphere

    Science.gov (United States)

    Luis, Aurélie; Colotte, Marthe; Tuffet, Sophie; Bonnet, Jacques

    2017-01-01

    Conventional storage of blood-derived fractions relies on cold. However, lately, ambient temperature preservation has been evaluated by several independent institutions that see economic and logistic advantages in getting rid of the cold chain. Here we validated a novel procedure for ambient temperature preservation of DNA in white blood cell and buffy coat lysates based on the confinement of the desiccated biospecimens under anoxic and anhydrous atmosphere in original hermetic minicapsules. For this validation we stored encapsulated samples either at ambient temperature or at several elevated temperatures to accelerate aging. We found that DNA extracted from stored samples was of good quality with a yield of extraction as expected. Degradation rates were estimated from the average fragment size of denatured DNA run on agarose gels and from qPCR reactions. At ambient temperature, these rates were too low to be measured but the degradation rate dependence on temperature followed Arrhenius’ law, making it possible to extrapolate degradation rates at 25°C. According to these values, the DNA stored in the encapsulated blood products would remain larger than 20 kb after one century at ambient temperature. At last, qPCR experiments demonstrated the compatibility of extracted DNA with routine DNA downstream analyses. Altogether, these results showed that this novel storage method provides an adequate environment for ambient temperature long term storage of high molecular weight DNA in dehydrated lysates of white blood cells and buffy coats. PMID:29190767

  17. Influence of variable heat transfer coefficient of fireworks and crackers on thermal explosion critical ambient temperature and time to ignition

    Directory of Open Access Journals (Sweden)

    Guo Zerong

    2016-01-01

    Full Text Available To study the effect of variable heat transfer coefficient of fireworks and crackers on thermal explosion critical ambient temperature and time to ignition, considering the heat transfer coefficient as the power function of temperature, mathematical thermal explosion steady state and unsteady-state model of finite cylindrical fireworks and crackers with complex shell structures are established based on two-dimensional steady state thermal explosion theory. The influence of variable heat transfer coefficient on thermal explosion critical ambient temperature and time to ignition are analyzed. When heat transfer coefficient is changing with temperature and in the condition of natural convection heat transfer, critical ambient temperature lessen, thermal explosion time to ignition shorten. If ambient temperature is close to critical ambient temperature, the influence of variable heat transfer coefficient on time to ignition become large. For firework with inner barrel in example analysis, the critical ambient temperature of propellant is 463.88 K and the time to ignition is 4054.9s at 466 K, 0.26 K and 450.8s less than without considering the change of heat transfer coefficient respectively. The calculation results show that the influence of variable heat transfer coefficient on thermal explosion time to ignition is greater in this example. Therefore, the effect of variable heat transfer coefficient should be considered into thermal safety evaluation of fireworks to reduce potential safety hazard.

  18. On exhaust emissions from petrol-fuelled passenger cars at low ambient temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Laurikko, J. [VTT Energy, Espoo (Finland). Energy Use

    1998-11-01

    The study at hand deals with regulated and unregulated exhaust emissions from petrol-fuelled cars at low ambient temperatures with present-day or near-future exhaust after treatment systems. The subject has been investigated at VTT over a decade and this report compiles data from various sub-studies carried out between the years 1993 - 1997. Each one of them viewed different aspects of the phenomenon, like determining the low-temperature response of today`s new cars employing three-way catalytic converters or assessing the long-term durability and the influence of vehicle mileage upon the low-temperature emissions performance. Within these studies, together more than 120 cars of model years from 1990 to 1997 have been tested. Most of them were normal, in-service vehicles with total mileages differing between only a few thousand kilometres for new cars up to 80,000 km or even more for the in-use vehicles. Both the US FTP75 and the European test cycle have been employed, and the ambient temperatures ranged from the baseline (+22 deg C) down to +- O deg C, -7 deg C and in some cases even to -20 deg C. The studies attested that new cars having today`s advanced emissions control systems produced fairly low levels of emissions when tested in conditions designated in the regulations that are the basis of the current new-vehicle certification. However, this performance was not necessarily attained at ambient temperatures that were below the normative range. Fairly widespread response was recorded, and cars having almost equal emissions output at baseline could produce largely deviating outcomes in low-temperature conditions. On average, CO and HC emissions increased by a factor of five to 10, depending on the ambient temperature and vehicle type. However, emissions of NO{sub x} were largely unaffected. Apart from these regulated emissions, many unregulated species were also determined, either by using traditional sampling and chromatography methods or on-line, employing

  19. On exergy analysis of industrial plants and significance of ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Rian, Berit

    2011-07-01

    The exergy analysis has been a relatively mature theory for more than 30 years. However, it is not that developed in terms of procedures for optimizing systems, which partly explains why it is not that common. Misconceptions and prejudices, even among scientists, are also partly to blame.The main objective of this work was to contribute to the development of an understanding and methodology of the exergy analysis. The thesis was mainly based on three papers, two of which provided very different examples from existing industrial systems in Norway, thus showing the societal perspective in terms of resource utilization and thermodynamics. The last paper and the following investigation were limited to certain aspects of ambient conditions. Two Norwegian operational plants have been studied, one operative for close to 30 years (Kaarstoe steam production and distribution system), while the other has just started its expected 30 years of production (Snoehvit LNG plant). In addition to mapping the current operational status of these plants, the study of the Kaarstoe steam production and distribution system concluded that the potential for increasing the thermodynamic performance by rather cautious actions was significant, whereas the study of the Snoehvit LNG plant showed the considerable profit which the Arctic location provided in terms of reduced fuel consumption. The significance of the ambient temperature led to the study of systems with two ambient bodies (i.e. ambient water and ambient air) of different temperatures, here three different systems were investigated: A regenerative steam injection gas turbine (RSTIG), a simple Linde air liquefaction plant (Air Liq) and an air-source heat pump water heater (HPWH). In particular, the effect of the chosen environment on exergy analysis was negligible for RSTIG, modest for Air Liq and critical for HPWH. It was found that the amount of exergy received from the alternative ambient body, compared to the main exergy flow of

  20. Relationship between mean body surface temperature measured by use of infrared thermography and ambient temperature in clinically normal pigs and pigs inoculated with Actinobacillus pleuropneumoniae.

    Science.gov (United States)

    Loughmiller, J A; Spire, M F; Dritz, S S; Fenwick, B W; Hosni, M H; Hogge, S B

    2001-05-01

    To determine the relationship between ambient temperature and mean body surface temperature (MBST) measured by use of infrared thermography (IRT) and to evaluate the ability of IRT to detect febrile responses in pigs following inoculation with Actinobacillus pleuropneumoniae. 28 crossbred barrows. Pigs (n = 4) were subjected to ambient temperatures ranging from 10 to 32 C in an environmental chamber. Infrared thermographs were obtained, and regression analysis was used to determine the relationship between ambient temperature and MBST. The remaining pigs were assigned to groups in an unbalanced randomized complete block design (6 A pleuropneumoniae-inoculated febrile pigs [increase in rectal temperature > or = 1.67 C], 6 A pleuropneumoniae-inoculated nonfebrile pigs [increase in rectal temperature temperatures were obtained for the period from 2 hours before to 18 hours after inoculation, and results were analyzed by use of repeated-measures ANOVA. A significant linear relationship was observed between ambient temperature and MBST (slope, 0.40 C). For inoculated febrile pigs, a treatment X method interaction was evident for rectal temperature and MBST, whereas inoculated nonfebrile pigs only had increased rectal temperatures, compared with noninoculated pigs. A method X time interaction resulted from the longer interval after inoculation until detection of an increase in MBST by use of IRT. Infrared thermography can be adjusted to account for ambient temperature and used to detect changes in MBST and radiant heat production attributable to a febrile response in pigs.

  1. Effects of ambient temperature on energy and nitrogen utilization in lipopolysaccharide-challenged growing pigs.

    Science.gov (United States)

    Campos, P H R F; Labussière, E; Hernández-García, J; Dubois, S; Renaudeau, D; Noblet, J

    2014-11-01

    High ambient temperature impacts feed intake, growth, and nutrient utilization in pigs. However, little is known on its effects on immune function and, therefore, on how or if it could modulate the utilization of nutrients in pigs exposed to an inflammatory challenge. The aim of this study was to evaluate the effects of high ambient temperature on energy and nitrogen utilization in pigs submitted to repeated injections of Escherichia coli lipopolysaccharide (LPS). Twenty-eight catheterized and pair-housed female pigs (55 kg BW) were assigned to 1 of the 2 thermal conditions: thermoneutrality (TN, 24°C) or high ambient temperature (HT, 30°C). Within each condition, pigs had a 2-wk adaptation period in climatic-controlled rooms and then were transferred to open-circuit respiration chambers. Pigs remained in respiration chambers for a period of 18 d, which was divided into a 7-d period without LPS (baseline) and a subsequent 11-d period with LPS administration (LPSperiod). The interaction between ambient temperature and period was not significant for most of the traits studied. At baseline, pigs kept at HT had lower ADFI (1,500 vs. 2,003 g/d; P nutrient digestibility compared with those kept at TN. Pigs kept at HT also consumed less ME (1,651 vs. 2,170 kJ · kg BW(-0.60) · d(-1); P = 0.01) and produced less heat (1,146 vs. 1,365 kJ · kg BW(-0.60) · d(-1); P nitrogen (-13.7 and -7.4 g/d) and ME intake (-594 and -335 kJ · kg BW(-0.60) · d(-1)) in TN and HT conditions, respectively; fecal digestibility of nutrients was not affected by LPS. During the LPSperiod, total heat production (HP) was decreased (P < 0.01) in both TN and HT groups (-190 and -104 kJ · kg BW(-0.60) · d(-1), respectively), in connection with the lower short-term thermic effect of feeding (P = 0.01) and resting HP (P < 0.01). In addition, the LPS induced a reduction in protein (P < 0.01) and fat deposition (P = 0.01) in pigs kept at TN (-79 and -73 g/d, respectively) and at HT (-41 and -44 g

  2. Increased ambient air temperature alters the severity of soil water repellency

    Science.gov (United States)

    van Keulen, Geertje; Sinclair, Kat; Hallin, Ingrid; Doerr, Stefan; Urbanek, Emilia; Quinn, Gerry; Matthews, Peter; Dudley, Ed; Francis, Lewis; Gazze, S. Andrea; Whalley, Richard

    2017-04-01

    Soil repellency, the inability of soils to wet readily, has detrimental environmental impacts such as increased runoff, erosion and flooding, reduced biomass production, inefficient use of irrigation water and preferential leaching of pollutants. Its impacts may exacerbate (summer) flood risks associated with more extreme drought and precipitation events. In this study we have tested the hypothesis that transitions between hydrophobic and hydrophilic soil particle surface characteristics, in conjunction with soil structural properties, strongly influence the hydrological behaviour of UK soils under current and predicted UK climatic conditions. We have addressed the hypothesis by applying different ambient air temperatures under controlled conditions to simulate the effect of predicted UK climatic conditions on the wettability of soils prone to develop repellency at different severities. Three UK silt-loam soils under permanent vegetation were selected for controlled soil perturbation studies. The soils were chosen based on the severity of hydrophobicity that can be achieved in the field: severe to extreme (Cefn Bryn, Gower, Wales), intermediate to severe (National Botanical Garden, Wales), and subcritical (Park Grass, Rothamsted Research near London). The latter is already highly characterised so was also used as a control. Soils were fully saturated with water and then allowed to dry out gradually upon exposure to controlled laboratory conditions. Soils were allowed to adapt for a few hours to a new temperature prior to initiation of the controlled experiments. Soil wettability was determined at highly regular intervals by measuring water droplet penetration times. Samples were collected at four time points: fully wettable, just prior to and after the critical soil moisture concentrations (CSC), and upon reaching air dryness (to constant weight), for further (ultra)metaproteomic and nanomechanical studies to allow integration of bulk soil characterisations with

  3. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Rooftop Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shen, Bo [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Bargach, Youssef [Navigant Consulting Inc., Burlington, MA (United States)

    2016-09-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for Low-Global Warming Potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants relative to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in packaged or Rooftop Unit (RTU) air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerants selection process, the test procedures, and the final results.

  4. Ambient temperature SNAD process treating anaerobic digester liquor of swine wastewater.

    Science.gov (United States)

    Daverey, Achlesh; Hung, Nien-Tzu; Dutta, Kasturi; Lin, Jih-Gaw

    2013-08-01

    In present study, effluent from anaerobic digestion of swine wastewater was treated by the simultaneous partial nitrification, anaerobic ammonium oxidation and denitrification (SNAD) process using a lab scale 5L sequencing batch reactor (SBR) under ambient temperature. The fluctuation of anaerobic digester liquor quality (COD, 387 ± 145 mg/L; TKN, 662 ± 190 mg/L; NH₄(+)-N, 519 ± 134 mg/L) and temperature created difficulties to develop a stable SNAD process in the SBR (days 1-285). Fed batch feeding strategy was adopted to have a stable condition in the reactor and overcome the negative effects of organic nitrogen. The average total nitrogen, NH₄(+)-N and COD removal efficiencies in the SBR under steady state conditions (days 485-523) were 80%, 96% and 76%, respectively. The results showed that presence of organic nitrogen, mode of feeding and reactor temperature affects the SNAD process. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Ambient temperature and mortality: an international study in four capital cities of East Asia.

    Science.gov (United States)

    Chung, Joo-Youn; Honda, Yasushi; Hong, Yun-Chul; Pan, Xiao-Chuan; Guo, Yue-Leon; Kim, Ho

    2009-12-20

    Extreme ambient temperature has been associated with increased daily mortality across the world. We describe the ambient temperature-mortality association for four capital cities in East Asia, Seoul, Beijing, Tokyo, and Taipei, and identify a threshold temperature for each city and the percent increase in mortality. We adapted generalized linear modeling with natural cubic splines (GLM+NS) to examine the association between daily mean apparent temperature (AT) and total mortality, as well as mortality due to respiratory (RD) and cardiovascular (CVD) causes in a threshold model. We conducted a time-series analysis adjusting for day of the week and long-term time trend. The study period differed by city. The threshold temperature for all seasons was estimated to be 30.1-33.5 degrees C, 31.3-32.3 degrees C, 29.4-30.8 degrees C, and 25.2 degrees -31.5 degrees C for Seoul, Beijing, Tokyo, and Taipei, respectively, on the same day. For the mean daily AT increase of 1 degrees C above the thresholds in Seoul, Tokyo, and Taipei, estimated percentage increases in daily total mortality were 2.7 (95% confidence interval (CI)=2.2-3.1), 1.7 (95% CI=1.5-2.0), and 4.3 (95% CI=2.9-5.7), respectively. Beijing provided no total mortality counts. Estimated percentage increases were 2.7-10.5 for RD mortality, 1.1-9.3 for CVD mortality in 4 cities. This study identified increased mortality due to exposure to elevated AT. The importance of effects of AT and city-specific threshold temperatures suggests that analyses of the impact of climate change should take regional differences into consideration.

  6. Lithium doping on covalent organic framework-320 for enhancing hydrogen storage at ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Liangzhi, E-mail: 15004110853@163.com; Liu, Qing

    2016-12-15

    Density Functional Theory (DFT) combines with grand canonical Monte Carlo (GCMC) simulations are performed to explore the effect of Li doping on the hydrogen storage capability of COF-320. The results show that the interaction energy between the H{sub 2} and the Li-doped COF-320 is about three times higher than that of pristine COF-320. GCMC simulations are employed to study the hydrogen uptake of Li-doped COF-320 at ambient temperature, further confirm that the lithium doping can improve the hydrogen uptake at ambient temperature. Our results demonstrate that Li-doped COFs have good potential in the field of hydrogen storage. - Graphical abstract: Fig. 1. The optimized cluster model used here to represent the COF-320 and possible adsorption sites (A, B, C) for adsorption of metals in the COF-320. The dangling bonds are terminated by H atoms. C, H, and N atoms are shown as gray, white, and blue colors, respectively. Fig. 2. The adsorption isotherm of H{sub 2} in the pristine and Li-doped COF-320 at 298 K. - Highlights: • The binding sites of single and two lithium atoms in COF-320 were studied. • The interaction energy between the H{sub 2} and the Li-doped COF-320 is about three times higher than that of pristine COF-320. • H{sub 2} uptakes on the Li-doped COFs obtain significant improvement at ambient temperature. • Lithium-doping is a successful strategy for improving hydrogen uptake.

  7. Strength of Geopolymer Cement Curing at Ambient Temperature by Non-Oven Curing Approaches: An Overview

    Science.gov (United States)

    Wattanachai, Pitiwat; Suwan, Teewara

    2017-06-01

    At the present day, a concept of environmentally friendly construction materials has been intensively studying to reduce the amount of releasing greenhouse gases. Geopolymer is one of the cementitious binders which can be produced by utilising pozzolanic wastes (e.g. fly ash or furnace slag) and also receiving much more attention as a low-CO2 emission material. However, to achieve excellent mechanical properties, heat curing process is needed to apply to geopolymer cement in a range of temperature around 40 to 90°C. To consume less oven-curing energy and be more convenience in practical work, the study on geopolymer curing at ambient temperature (around 20 to 25°C) is therefore widely investigated. In this paper, a core review of factors and approaches for non-oven curing geopolymer has been summarised. The performance, in term of strength, of each non-oven curing method, is also presented and analysed. The main aim of this review paper is to gather the latest study of ambient temperature curing geopolymer and to enlarge a feasibility of non-oven curing geopolymer development. Also, to extend the directions of research work, some approaches or techniques can be combined or applied to the specific properties for in-field applications and embankment stabilization by using soil-cement column.

  8. Microscale solid-state thermal diodes enabling ambient temperature thermal circuits for energy applications.

    Science.gov (United States)

    Wang, Song; Cottrill, Anton L; Kunai, Yuichiro; Toland, Aubrey R; Liu, Pingwei; Wang, Wen-Jun; Strano, Michael S

    2017-05-24

    Thermal diodes, or devices that transport thermal energy asymmetrically, analogous to electrical diodes, hold promise for thermal energy harvesting and conservation, as well as for phononics or information processing. The junction of a phase change material and phase invariant material can form a thermal diode; however, there are limited constituent materials available for a given target temperature, particularly near ambient. In this work, we demonstrate that a micro and nanoporous polystyrene foam can house a paraffin-based phase change material, fused to PMMA, to produce mechanically robust, solid-state thermal diodes capable of ambient operation with Young's moduli larger than 11.5 MPa and 55.2 MPa above and below the melting transition point, respectively. Moreover, the composites show significant changes in thermal conductivity above and below the melting point of the constituent paraffin and rectification that is well-described by our previous theory and the Maxwell-Eucken model. Maximum thermal rectifications range from 1.18 to 1.34. We show that such devices perform reliably enough to operate in thermal diode bridges, dynamic thermal circuits capable of transforming oscillating temperature inputs into single polarity temperature differences - analogous to an electrical diode bridge with widespread implications for transient thermal energy harvesting and conservation. Overall, our approach yields mechanically robust, solid-state thermal diodes capable of engineering design from a mathematical model of phase change and thermal transport, with implications for energy harvesting.

  9. Design, development and implementation of the IR signaling techniques for monitoring ambient and body temperature

    International Nuclear Information System (INIS)

    Baqai, A.

    2014-01-01

    Healthcare systems such as hospitals, homecare, telemedicine, and physical rehabilitation are expected to be revolutionized by WBAN (Wireless Body Area Networks). This research work aims to investigate, design, optimize, and demonstrate the applications of IR (Infra-Red) communication systems in WBAN. It is aimed to establish a prototype WBAN system capable of measuring Ambient and Body Temperature using LM35 as temperature sensor and transmitting and receiving the data using optical signals. The corresponding technical challenges that have to be faced are also discussed in this paper. Investigations are carried out to efficiently design the hardware using low-cost and low power optical transceivers. The experimental results reveal the successful transmission and reception of Ambient and Body Temperatures over short ranges i.e. up to 3-4 meters. A simple IR transceiver with an LED (Light Emitting Diodes), TV remote control IC and Arduino microcontroller is designed to perform the transmission with sufficient accuracy and ease. Experiments are also performed to avoid interference from other sources like AC and TV remote control signals by implementing IR tags. (author)

  10. 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.

  11. Microscale solid-state thermal diodes enabling ambient temperature thermal circuits for energy applications

    KAUST Repository

    Wang, Song

    2017-05-10

    Thermal diodes, or devices that transport thermal energy asymmetrically, analogous to electrical diodes, hold promise for thermal energy harvesting and conservation, as well as for phononics or information processing. The junction of a phase change material and phase invariant material can form a thermal diode; however, there are limited constituent materials available for a given target temperature, particularly near ambient. In this work, we demonstrate that a micro and nanoporous polystyrene foam can house a paraffin-based phase change material, fused to PMMA, to produce mechanically robust, solid-state thermal diodes capable of ambient operation with Young\\'s moduli larger than 11.5 MPa and 55.2 MPa above and below the melting transition point, respectively. Moreover, the composites show significant changes in thermal conductivity above and below the melting point of the constituent paraffin and rectification that is well-described by our previous theory and the Maxwell–Eucken model. Maximum thermal rectifications range from 1.18 to 1.34. We show that such devices perform reliably enough to operate in thermal diode bridges, dynamic thermal circuits capable of transforming oscillating temperature inputs into single polarity temperature differences – analogous to an electrical diode bridge with widespread implications for transient thermal energy harvesting and conservation. Overall, our approach yields mechanically robust, solid-state thermal diodes capable of engineering design from a mathematical model of phase change and thermal transport, with implications for energy harvesting.

  12. Influence of Physical Activity and Ambient Temperature on Hydration: The European Hydration Research Study (EHRS

    Directory of Open Access Journals (Sweden)

    Ricardo Mora-Rodriguez

    2016-04-01

    Full Text Available This study explored the effects of physical activity (PA and ambient temperature on water turnover and hydration status. Five-hundred seventy three healthy men and women (aged 20–60 years from Spain, Greece and Germany self-reported PA, registered all food and beverage intake, and collected 24-h urine during seven consecutive days. Fasting blood samples were collected at the onset and end of the study. Food moisture was assessed using nutritional software to account for all water intake which was subtracted from daily urine volume to allow calculation of non-renal water loss (i.e., mostly sweating. Hydration status was assessed by urine and blood osmolality. A negative association was seen between ambient temperature and PA (r = −0.277; p < 0.001. Lower PA with high temperatures did not prevent increased non-renal water losses (i.e., sweating and elevated urine and blood osmolality (r = 0.218 to 0.163 all p < 0.001. When summer and winter data were combined PA was negatively associated with urine osmolality (r = −0.153; p = 0.001. Our data suggest that environmental heat acts to reduce voluntary PA but this is not sufficient to prevent moderate dehydration (increased osmolality. On the other hand, increased PA is associated with improved hydration status (i.e., lower urine and blood osmolality.

  13. Ambient air pollution, temperature and out-of-hospital coronary deaths in Shanghai, China.

    Science.gov (United States)

    Dai, Jinping; Chen, Renjie; Meng, Xia; Yang, Changyuan; Zhao, Zhuohui; Kan, Haidong

    2015-08-01

    Few studies have evaluated the effects of ambient air pollution and temperature in triggering out-of-hospital coronary deaths (OHCDs) in China. We evaluated the associations of air pollution and temperature with daily OHCDs in Shanghai, China from 2006 to 2011. We applied an over-dispersed generalized additive model and a distributed lag nonlinear model to analyze the effects of air pollution and temperature, respectively. A 10 μg/m(3) increase in the present-day PM10, PM2.5, SO2, NO2 and CO were associated with increases in OHCD mortality of 0.49%, 0.68%, 0.88%, 1.60% and 0.08%, respectively. A 1 °C decrease below the minimum-mortality temperature corresponded to a 3.81% increase in OHCD mortality on lags days 0-21, and a 1 °C increase above minimum-mortality temperature corresponded to a 4.61% increase over lag days 0-3. No effects were found for in-hospital coronary deaths. This analysis suggests that air pollution, low temperature and high temperature may increase the risk of OHCDs. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring.

    Science.gov (United States)

    Wei, Peng; Ning, Zhi; Ye, Sheng; Sun, Li; Yang, Fenhuan; Wong, Ka Chun; Westerdahl, Dane; Louie, Peter K K

    2018-01-23

    The increasing applications of low-cost air sensors promises more convenient and cost-effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series) for carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO₂), and oxidants (O x ) were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side-by-side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over-arching observation of this study is that the low-cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi-month stability, temperature, and humidity, and considered the interaction of oxidant gases NO₂ and ozone on a newly introduced oxidant sensor.

  15. Antioxidant compounds of kiwifruit during post-ripening process at ambient temperature

    Science.gov (United States)

    Liang, D.; Lv, X. L.; Wang, J.; Xia, H.; Xie, Y.; Li, M. Z.; Wang, Y. Z.

    2017-09-01

    Kiwifruit is well-known for an excellent source of antioxidants. In this study, contents of total phenolics (TPC), total flavonoids (TFC), total flavanols (TFAC) and vitamin C were investigated in different fruit tissues during post-ripening process at ambient temperature. The results explored that TPC and TFC showed declining trend with the increase in storage interval in different tissues. TFAC raised with the increase in storage interval in different fruit tissues, while was followed a decrease in later process. Vitamin C content was stable in outer and inner pericarp in prometaphase of post-ripening.

  16. Effect of low and high ambient temperatures on metabolism of radioiodine by the lactating goat

    International Nuclear Information System (INIS)

    Lengemann, F.W.

    1979-01-01

    Two lactating goats given an oral dose of iodine-125 excreted 16.8, 52.5, and 9.8% of the dose into the milk, urine, and feces when the ambient temperature was 33 C. The thyroids contained about .7% of the oral dose. At 5 C only 2.6% of the radioiodine was in the milk, but 71.2% was in the urine, 18.1% in the feces, and about 10% in the thyroid. The reduced competition by the thyroid plus enhanced transfer of radioiodine from blood to milk at 33 C was responsible for the large transfer of radioiodine into milk at 33 C

  17. Gold-Catalyzed Aerobic Oxidation of 5-Hydroxymethylfurfural in Water at Ambient Temperature

    DEFF Research Database (Denmark)

    Gorbanev, Yury; Kegnæs, Søren; Woodley, John

    2009-01-01

    The aerobic oxidation of 5-hydroxymethylfurfural, a versatile biomass-derived chemical, is examined in water with a titania-supported gold-nanoparticle catalyst at ambient temperature (30 degrees C). The selectivity of the reaction towords 2,5-furandicarboxylic acid and the intermediate oxidation....... product 5-hydroxymethyl-2-furancarboxylic acid is found to depend on the amount of added base and the oxygen pressure, suggesting that the reaction proceeds via initial oxidation of the aldehyde moiety followed by oxidation of the hydroxymethyl group of 5-hydroxymethylfurfural. Under optimized reaction...

  18. Volatility and lifetime against OH heterogeneous reaction of ambient isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA)

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Weiwei; Palm, Brett B.; Day, Douglas A.; Campuzano-Jost, Pedro; Krechmer, Jordan E.; Peng, Zhe; de Sá, Suzane S.; Martin, Scot T.; Alexander, M. Lizabeth; Baumann, Karsten; Hacker, Lina; Kiendler-Scharr, Astrid; Koss, Abigail R.; de Gouw, Joost A.; Goldstein, Allen H.; Seco, Roger; Sjostedt, Steven J.; Park, Jeong-Hoo; Guenther, Alex B.; Kim, Saewung; Canonaco, Francesco; Prévôt, André S. H.; Brune, William H.; Jimenez, Jose L.

    2016-01-01

    Isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA) can contribute substantially to organic aerosol (OA) concentrations in forested areas under low NO conditions, hence significantly influencing the regional and global OA budgets, accounting, for example, for 16–36 % of the submicron OA in the southeastern United States (SE US) summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR). New IEPOX-SOA formation in the reactor was negligible, as the OFR does not accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding ~100 µg m-3 of pure H2SO4 to the ambient air allows IEPOX-SOA to be efficiently formed in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH) was estimated as 4.0 ± 2.0 ×10-13 cm3 molec-1 s-1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (> 1 × 1012 molec cm-3 s), the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report, for the first time, OH reactive uptake coefficients (γOH = 0.59±0.33 in SE US and γOH = 0.68±0.38 in Amazon) for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface-area-limited OH uptake

  19. Volatility and lifetime against OH heterogeneous reaction of ambient isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA

    Directory of Open Access Journals (Sweden)

    W. Hu

    2016-09-01

    Full Text Available Isoprene-epoxydiols-derived secondary organic aerosol (IEPOX-SOA can contribute substantially to organic aerosol (OA concentrations in forested areas under low NO conditions, hence significantly influencing the regional and global OA budgets, accounting, for example, for 16–36 % of the submicron OA in the southeastern United States (SE US summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR. New IEPOX-SOA formation in the reactor was negligible, as the OFR does not accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding  ∼  100 µg m−3 of pure H2SO4 to the ambient air allows IEPOX-SOA to be efficiently formed in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH was estimated as 4.0 ± 2.0  ×  10−13 cm3 molec−1 s−1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (>  1  ×  1012 molec cm−3 s, the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report, for the first time, OH reactive uptake coefficients (γOH =  0.59 ± 0.33 in SE US and γOH =  0.68 ± 0.38 in Amazon for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface-area-limited OH uptake. No decrease of kOH was observed as OH concentrations increased. These observations of physicochemical

  20. Revealing the association between cerebrovascular accidents and ambient temperature: a meta-analysis

    Science.gov (United States)

    Zorrilla-Vaca, Andrés; Healy, Ryan Jacob; Silva-Medina, Melissa M.

    2017-05-01

    The association between cerebrovascular accidents (CVA) and weather has been described across several studies showing multiple conflicting results. In this paper, we aim to conduct a meta-analysis to further clarify this association, as well as to find the potential sources of heterogeneity. PubMed, EMBASE, and Google Scholar were searched from inception through 2015, for articles analyzing the correlation between the incidence of CVA and temperature. A pooled effect size (ES) was estimated using random effects model and expressed as absolute values. Subgroup analyses by type of CVA were also performed. Heterogeneity and influence of covariates—including geographic latitude of the study site, male percentage, average temperature, and time interval—were assessed by meta-regression analysis. Twenty-six articles underwent full data extraction and scoring. A total of 19,736 subjects with CVA from 12 different countries were included and grouped as ischemic strokes (IS; n = 14,199), intracerebral hemorrhages (ICH; n = 3798), and subarachnoid hemorrhages (SAH; n = 1739). Lower ambient temperature was significantly associated with increase in incidence of overall CVA when using unadjusted (pooled ES = 0.23, P < 0.001) and adjusted data (pooled ES = 0.03, P = 0.003). Subgroup analyses showed that lower temperature has higher impact on the incidence of ICH (pooled ES = 0.34, P < 0.001), than that of IS (pooled ES = 0.22, P < 0.001) and SAH (pooled ES = 0.11, P = 0.012). In meta-regression analysis, the geographic latitude of the study site was the most influencing factor on this association ( Z-score = 8.68). Synthesis of the existing data provides evidence supporting that a lower ambient temperature increases the incidence of CVA. Further population-based studies conducted at negative latitudes are needed to clarify the influence of this factor.

  1. Projecting future summer mortality due to ambient ozone concentration and temperature changes

    Science.gov (United States)

    Lee, Jae Young; Lee, Soo Hyun; Hong, Sung-Chul; Kim, Ho

    2017-05-01

    Climate change is known to affect the human health both directly by increased heat stress and indirectly by altering environments, particularly by altering the rate of ambient ozone formation in the atmosphere. Thus, the risks of climate change may be underestimated if the effects of both future temperature and ambient ozone concentrations are not considered. This study presents a projection of future summer non-accidental mortality in seven major cities of South Korea during the 2020s (2016-2025) and 2050s (2046-2055) considering changes in temperature and ozone concentration, which were predicted by using the HadGEM3-RA model and Integrated Climate and Air Quality Modeling System, respectively. Four Representative Concentration Pathway (RCP) scenarios (RCP 2.6, 4.5, 6.0, and 8.5) were considered. The result shows that non-accidental summer mortality will increase by 0.5%, 0.0%, 0.4%, and 0.4% in the 2020s, 1.9%, 1.5%, 1.2%, and 4.4% in the 2050s due to temperature change compared to the baseline mortality during 2001-2010, under RCP 2.6, 4.5, 6.0, and 8.5, respectively, whereas the mortality will increase by 0.0%, 0.5%, 0.0%, and 0.5% in the 2020s, and 0.2%, 0.2%, 0.4%, and 0.6% in the 2050s due to ozone concentration change. The projection result shows that the future summer morality in South Korea is increased due to changes in both temperature and ozone, and the magnitude of ozone-related increase is much smaller than that of temperature-related increase, especially in the 2050s.

  2. In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor

    Science.gov (United States)

    Palm, Brett B.; Campuzano-Jost, Pedro; Ortega, Amber M.; Day, Douglas A.; Kaser, Lisa; Jud, Werner; Karl, Thomas; Hansel, Armin; Hunter, James F.; Cross, Eben S.; Kroll, Jesse H.; Peng, Zhe; Brune, William H.; Jimenez, Jose L.

    2016-03-01

    An oxidation flow reactor (OFR) is a vessel inside which the concentration of a chosen oxidant can be increased for the purpose of studying SOA formation and aging by that oxidant. During the BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H2O, Organics & Nitrogen-Rocky Mountain Biogenic Aerosol Study) field campaign, ambient pine forest air was oxidized by OH radicals in an OFR to measure the amount of SOA that could be formed from the real mix of ambient SOA precursor gases, and how that amount changed with time as precursors changed. High OH concentrations and short residence times allowed for semicontinuous cycling through a large range of OH exposures ranging from hours to weeks of equivalent (eq.) atmospheric aging. A simple model is derived and used to account for the relative timescales of condensation of low-volatility organic compounds (LVOCs) onto particles; condensational loss to the walls; and further reaction to produce volatile, non-condensing fragmentation products. More SOA production was observed in the OFR at nighttime (average 3 µg m-3 when LVOC fate corrected) compared to daytime (average 0.9 µg m-3 when LVOC fate corrected), with maximum formation observed at 0.4-1.5 eq. days of photochemical aging. SOA formation followed a similar diurnal pattern to monoterpenes, sesquiterpenes, and toluene+p-cymene concentrations, including a substantial increase just after sunrise at 07:00 local time. Higher photochemical aging (> 10 eq. days) led to a decrease in new SOA formation and a loss of preexisting OA due to heterogeneous oxidation followed by fragmentation and volatilization. When comparing two different commonly used methods of OH production in OFRs (OFR185 and OFR254-70), similar amounts of SOA formation were observed. We recommend the OFR185 mode for future forest studies. Concurrent gas-phase measurements of air after OH oxidation illustrate the decay of primary VOCs, production of small oxidized organic

  3. Modeling seasonal surface temperature variations in secondary tropical dry forests

    Science.gov (United States)

    Cao, Sen; Sanchez-Azofeifa, Arturo

    2017-10-01

    Secondary tropical dry forests (TDFs) provide important ecosystem services such as carbon sequestration, biodiversity conservation, and nutrient cycle regulation. However, their biogeophysical processes at the canopy-atmosphere interface remain unknown, limiting our understanding of how this endangered ecosystem influences, and responds to the ongoing global warming. To facilitate future development of conservation policies, this study characterized the seasonal land surface temperature (LST) behavior of three successional stages (early, intermediate, and late) of a TDF, at the Santa Rosa National Park (SRNP), Costa Rica. A total of 38 Landsat-8 Thermal Infrared Sensor (TIRS) data and the Surface Reflectance (SR) product were utilized to model LST time series from July 2013 to July 2016 using a radiative transfer equation (RTE) algorithm. We further related the LST time series to seven vegetation indices which reflect different properties of TDFs, and soil moisture data obtained from a Wireless Sensor Network (WSN). Results showed that the LST in the dry season was 15-20 K higher than in the wet season at SRNP. We found that the early successional stages were about 6-8 K warmer than the intermediate successional stages and were 9-10 K warmer than the late successional stages in the middle of the dry season; meanwhile, a minimum LST difference (0-1 K) was observed at the end of the wet season. Leaf phenology and canopy architecture explained most LST variations in both dry and wet seasons. However, our analysis revealed that it is precipitation that ultimately determines the LST variations through both biogeochemical (leaf phenology) and biogeophysical processes (evapotranspiration) of the plants. Results of this study could help physiological modeling studies in secondary TDFs.

  4. Liquid structure of trihexyltetradecylphosphonium chloride at ambient temperature: an X-ray scattering and simulation study.

    Science.gov (United States)

    Gontrani, Lorenzo; Russina, Olga; Celso, Fabrizio Lo; Caminiti, Ruggero; Annat, Gary; Triolo, Alessandro

    2009-07-09

    We report on an experimental and simulation study done on a representative room temperature ionic liquid, namely tetradecyltrihexylphosphonium chloride, at ambient conditions. The study was conducted using small and wide angle X-ray scattering and molecular dynamics simulations. Both approaches converge in indicating that this material is characterized by the existence of strong P-Cl interactions (with characteristic distances between 3.5 and 5.0 A) and by the occurrence of nanoscale segregation, despite the symmetric nature of the cation and similarly to other room temperature ionic liquids. A good agreement is found between the structure factor and pair correlation functions obtained from MD simulations and the corresponding experimental observables, thus strongly validating the interaction potential used in the simulations.

  5. Estimating methane emissions from landfills based on rainfall, ambient temperature, and waste composition: The CLEEN model.

    Science.gov (United States)

    Karanjekar, Richa V; Bhatt, Arpita; Altouqui, Said; Jangikhatoonabad, Neda; Durai, Vennila; Sattler, Melanie L; Hossain, M D Sahadat; Chen, Victoria

    2015-12-01

    Accurately estimating landfill methane emissions is important for quantifying a landfill's greenhouse gas emissions and power generation potential. Current models, including LandGEM and IPCC, often greatly simplify treatment of factors like rainfall and ambient temperature, which can substantially impact gas production. The newly developed Capturing Landfill Emissions for Energy Needs (CLEEN) model aims to improve landfill methane generation estimates, but still require inputs that are fairly easy to obtain: waste composition, annual rainfall, and ambient temperature. To develop the model, methane generation was measured from 27 laboratory scale landfill reactors, with varying waste compositions (ranging from 0% to 100%); average rainfall rates of 2, 6, and 12 mm/day; and temperatures of 20, 30, and 37°C, according to a statistical experimental design. Refuse components considered were the major biodegradable wastes, food, paper, yard/wood, and textile, as well as inert inorganic waste. Based on the data collected, a multiple linear regression equation (R(2)=0.75) was developed to predict first-order methane generation rate constant values k as functions of waste composition, annual rainfall, and temperature. Because, laboratory methane generation rates exceed field rates, a second scale-up regression equation for k was developed using actual gas-recovery data from 11 landfills in high-income countries with conventional operation. The Capturing Landfill Emissions for Energy Needs (CLEEN) model was developed by incorporating both regression equations into the first-order decay based model for estimating methane generation rates from landfills. CLEEN model values were compared to actual field data from 6 US landfills, and to estimates from LandGEM and IPCC. For 4 of the 6 cases, CLEEN model estimates were the closest to actual. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Effect of ambient temperature on the efficiency of the PCPDTBT: PC71BM BHJ solar cells

    Science.gov (United States)

    Ahmad, Zubair; Touati, Farid; Muhammad, Fahmi F.; Najeeb, Mansoor Ani; Shakoor, R. A.

    2017-07-01

    In this research article, the influence of environment temperature on the performance of the organic bulk heterojunction organic solar cells has been investigated. We describe the effect of ambient temperature on the efficiency of poly-[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta-[2,1-b;3,4-b']dithiophene)-alt-4,7-(2,1,3-benzothiadiazole)] (PCPDTBT) and [6, 6]-phenylC71-butyric-acid-methyl-ester (PC71BM)-based bulk heterojunction (BHJ) organic solar cells. The current-voltage characteristics of the ITO/PEDOT:PSS/PCPDTBT:PC71BM/Al solar cells are recorded in the temperature range of 25-60 °C under 100 mW/cm2 solar irradiation. The short-circuit current ( J sc) of the solar cells increased from 4.28 to 9.23 mAcm-2 when the temperature elevated from 25 to 55 °C. However, the open-circuit voltage ( V oc) and fill factor (FF) of the cells almost remained unchanged over the whole investigated temperature range. The values of V oc and FF are found to be 0.58 ± 01 and 0.60 ± 0.12 V, respectively. The results clearly indicate that the maximum efficiency of the ITO/PEDOT:PSS/PCPDTBT:PC71BM/Al solar cells can be achieved in the range of 52-58 °C.

  7. Effects of ambient temperature on adaptive thermogenesis during maintenance of reduced body weight in mice

    Science.gov (United States)

    Ravussin, Yann; LeDuc, Charles A.; Watanabe, Kazuhisa

    2012-01-01

    We showed previously that, at ambient room temperature (22°C), mice maintained at 20% below their initial body weight by calorie restriction expend energy at a rate below that which can be accounted for by the decrease of fat and fat-free mass. Food-restricted rodents may become torpid at subthermoneutral temperatures, a possible confounding factor when using mice as human models in obesity research. We examined the bioenergetic, hormonal, and behavioral responses to maintenance of a 20% body weight reduction in singly housed C57BL/6J +/+ and Lepob mice housed at both 22°C and 30°C. Weight-reduced high-fat-fed diet mice (HFD-WR) showed similar quantitative reductions in energy expenditure—adjusted for body mass and composition—at both 22°C and 30°C: −1.4 kcal/24 h and −1.6 kcal/24 h below predicted, respectively, and neither group entered torpor. In contrast, weight-reduced Lepob mice (OB-WR) housed at 22°C became torpid in the late lights-off period (0200–0500) but did not when housed at 30°C. These studies indicate that mice with an intact leptin axis display similar decreases in “absolute” energy expenditure in response to weight reduction at both 22°C and 30°C ambient temperature. More importantly, the “percent” decrease in total energy expenditure observed in the HFD-WR compared with AL mice is much greater at 30°C (−19%) than at 22°C (−10%). Basal energy expenditure demands are ∼45% lower in mice housed at 30°C vs. 22°C, since the mice housed at thermoneutrality do not allocate extra energy for heat production. The higher total energy expenditure of mice housed at 22°C due to these increased thermogenic demands may mask physiologically relevant changes in energy expenditure showing that ambient temperature must be carefully considered when quantifying energy metabolism in both rodents and humans. PMID:22761182

  8. Ambient temperature and emergency department visits: Time-series analysis in 12 Chinese cities.

    Science.gov (United States)

    Zhao, Qi; Zhang, Yongming; Zhang, Wenyi; Li, Shanshan; Chen, Gongbo; Wu, Yanbin; Qiu, Chen; Ying, Kejing; Tang, Huaping; Huang, Jian-An; Williams, Gail; Huxley, Rachel; Guo, Yuming

    2017-05-01

    The association between ambient temperature and mortality has been well documented worldwide. However, limited data are available on nonfatal health outcomes, such as emergency department visits (EDVs), particularly from China. To examine the temperature-EDV association in 12 Chinese cities; and to assess the modification effects by region, gender and age. Daily meteorological data and non-accidental EDVs were collected during 2011-2014. Poisson regression with distributed lag non-linear model was applied to examine the temperature-lag-EDV association in each city. The effect estimates were pooled using multivariate meta-analysis at the national and regional level. Stratified analyses were performed by gender and age-groups. Sensitivity analyses adjusting for air pollution and relative humidity were conducted. A total of 4,443,127 EDVs were collected from the 12 cities. Both cold and hot temperatures were associated with increased risk of EDVs, with minimum-mortality temperature located at 64th percentile of temperature. The effect of cold temperature appeared on day 2 and persisted until day 30, causing a cumulative relative risk (RR) of 1.80 (1.54, 2.11). The effect of hot temperature appeared immediately and lasted until day 3, with a cumulative RR of 1.15 (1.03, 1.29). The effect of temperature on EDVs was similar in male and female but was attenuated with increasing age. The effect of cold temperature on EDVs was greater in southern areas of the country whereas the hot effect was greater in northern cities. The association was robust to a large range of sensitivity analyses. In China, there is a U-shaped association between temperature and risk of EDVs that is independent of air pollution and humidity. The temperature-EDV association varies with latitude and age-groups but is not affected by gender. Forecasting models for hospital emergency departments may be improved if temperature is included as an independent predictor. Copyright © 2017 Elsevier Ltd. All

  9. Sensor-less control of the methanol concentration of direct methanol fuel cells at varying ambient temperatures

    International Nuclear Information System (INIS)

    An, Myung-Gi; Mehmood, Asad; Ha, Heung Yong

    2014-01-01

    Highlights: • A new algorithm is proposed for the sensor-less control of methanol concentration. • Two different strategies are used depending on the ambient temperatures. • Energy efficiency of the DMFC system has been improved by using the new algorithm. - Abstract: A new version of an algorithm is used to control the methanol concentration in the feed of DMFC systems without using methanol sensors under varying ambient temperatures. The methanol concentration is controlled indirectly by controlling the temperature of the DMFC stack, which correlates well with the methanol concentration. Depending on the ambient temperature relative to a preset reference temperature, two different strategies are used to control the stack temperature: either reducing the cooling rate of the methanol solution passing through an anode-side heat exchanger; or, lowering the pumping rate of the pure methanol to the depleted feed solution. The feasibility of the algorithm is evaluated using a DMFC system that consists of a 200 W stack and the balance of plant (BOP). The DMFC system includes a sensor-less methanol controller that is operated using a LabView system as the central processing unit. The algorithm is experimentally confirmed to precisely control the methanol concentration and the stack temperature at target values under an environment of varying ambient temperatures

  10. Pressure induced ionic-superionic transition in silver iodide at ambient temperature.

    Science.gov (United States)

    Han, Y H; Wang, H B; Troyan, I A; Gao, C X; Eremets, M I

    2014-01-28

    Silver iodide (AgI-V) is an archetypical ionic compound for studying the formation mechanism of a superionic state. Previous studies have proven that superionic AgI with high ionic conductivity greater than 0.1 Ω(-1)cm(-1) could only be obtained at high temperatures. We show in this paper that high pressure could also induce the superionic state in AgI even at ambient temperature. Using electrochemical impedance spectroscopy, we investigated Ag(+) ions diffusing in rock-salt structured AgI-III and KOH-type AgI-V under high pressures and directly observed the superionic state in AgI-V. The diffusion coefficient of AgI-V is ∼3.4 × 10(-4)-8.6 × 10(-4) cm(2)/s in the investigated pressure range of 12-17 GPa, comparable with those of superionic α-AgI and AgI-III'. By analyzing the half infinite length Warburg diffusion process, two parameters α and β, which closely relate to the disordered state of Ag(+) ions, have been determined and it was suggested that Ag(+) ions in AgI-V become disordered. The ionic conductivity of AgI-V is three orders of magnitude higher than that of AgI-III, and has reached around 0.1 Ω(-1)cm(-1). Evidence for all three, the diffusion coefficient, α and β, and conductivity have proven that AgI-V is a superionic conductor at ambient temperature.

  11. Impact Analysis of Temperature and Humidity Conditions on Electrochemical Sensor Response in Ambient Air Quality Monitoring

    Directory of Open Access Journals (Sweden)

    Peng Wei

    2018-01-01

    Full Text Available The increasing applications of low-cost air sensors promises more convenient and cost-effective systems for air monitoring in many places and under many conditions. However, the data quality from such systems has not been fully characterized and may not meet user expectations in research and regulatory uses, or for use in citizen science. In our study, electrochemical sensors (Alphasense B4 series for carbon monoxide (CO, nitric oxide (NO, nitrogen dioxide (NO2, and oxidants (Ox were evaluated under controlled laboratory conditions to identify the influencing factors and quantify their relation with sensor outputs. Based on the laboratory tests, we developed different correction methods to compensate for the impact of ambient conditions. Further, the sensors were assembled into a monitoring system and tested in ambient conditions in Hong Kong side-by-side with regulatory reference monitors, and data from these tests were used to evaluate the performance of the models, to refine them, and validate their applicability in variable ambient conditions in the field. The more comprehensive correction models demonstrated enhanced performance when compared with uncorrected data. One over-arching observation of this study is that the low-cost sensors may promise excellent sensitivity and performance, but it is essential for users to understand and account for several key factors that may strongly affect the nature of sensor data. In this paper, we also evaluated factors of multi-month stability, temperature, and humidity, and considered the interaction of oxidant gases NO2 and ozone on a newly introduced oxidant sensor.

  12. Forty years increase of the air ambient temperature in Greece: The impact on buildings

    International Nuclear Information System (INIS)

    Kapsomenakis, J.; Kolokotsa, D.; Nikolaou, T.; Santamouris, M.; Zerefos, S.C.

    2013-01-01

    Highlights: • Forty years hourly data series from nine meteorological stations in Greece are analysed. • The air temperature increase influences the buildings’ energy demand. • A typical office building’s energy demand is examined. • The heating load is decreased by about 1 kWh/m 2 per decade. • The cooling load is increased by about 5 kWh/m 2 per decade. - Abstract: Air temperatures in urban areas continue to increase because of the heat island phenomenon (UHI) and the undeniable warming of the lower atmosphere during the past few decades. The observed high ambient air temperatures intensify the energy demand in cities, deteriorate urban comfort conditions, endanger the vulnerable population and amplify pollution problems especially in regions with hot climatic conditions. The present paper analyses 40 years of hourly data series from nine meteorological stations in Greece in order to understand the impact of air temperature and relative humidity trends on the energy consumption of buildings. Using a typical office building, the analysis showed that for the period in question the heating load in the Greek building sector has decreased by about 1 kWh/m 2 per decade, while the cooling load increased by about 5 kWh/m 2 per decade. This phenomenon has major environmental, economic and social consequences, which will be amplified in the upcoming decades in view of the expected man-made climatic changes in this geographic area

  13. Influence of Ambient Temperature on the CO2 Emitted With Exhaust Gases of Gasoline Vehicles

    Science.gov (United States)

    Chainikov, D.; Chikishev, E.; Anisimov, I.; Gavaev, A.

    2016-08-01

    This article focuses on the regulation of CO2 emitted in the exhaust gases of gasoline vehicles. Based on comparing the world practices of restrictive measures on greenhouse gas emissions with Russian legislation, we conclude that there is a need to adjust the limits of CO2 emission taking into account the negative impact of ambient temperature on CO2 emission. The climatic conditions of many countries stipulate the use of vehicles in temperatures below zero. At the same time, the existing regulations fully take into account the temperature features of the various countries, which casts doubt on the existence of uniform emission standards for all countries. Here, we conduct an experiment on one of the most popular cars in Russia: the Mitsubishi Lancer 9. We establish that lower temperatures are correlated with larger concentrations of CO2 in the exhaust gases. We draw a conclusion about the need to account for the actual operating conditions when establishing limit values on CO2 emissions of vehicles.

  14. A hybrid downscaling procedure for estimating the vertical distribution of ambient temperature in local scale

    Science.gov (United States)

    Yiannikopoulou, I.; Philippopoulos, K.; Deligiorgi, D.

    2012-04-01

    The vertical thermal structure of the atmosphere is defined by a combination of dynamic and radiation transfer processes and plays an important role in describing the meteorological conditions at local scales. The scope of this work is to develop and quantify the predictive ability of a hybrid dynamic-statistical downscaling procedure to estimate the vertical profile of ambient temperature at finer spatial scales. The study focuses on the warm period of the year (June - August) and the method is applied to an urban coastal site (Hellinikon), located in eastern Mediterranean. The two-step methodology initially involves the dynamic downscaling of coarse resolution climate data via the RegCM4.0 regional climate model and subsequently the statistical downscaling of the modeled outputs by developing and training site-specific artificial neural networks (ANN). The 2.5ox2.5o gridded NCEP-DOE Reanalysis 2 dataset is used as initial and boundary conditions for the dynamic downscaling element of the methodology, which enhances the regional representivity of the dataset to 20km and provides modeled fields in 18 vertical levels. The regional climate modeling results are compared versus the upper-air Hellinikon radiosonde observations and the mean absolute error (MAE) is calculated between the four grid point values nearest to the station and the ambient temperature at the standard and significant pressure levels. The statistical downscaling element of the methodology consists of an ensemble of ANN models, one for each pressure level, which are trained separately and employ the regional scale RegCM4.0 output. The ANN models are theoretically capable of estimating any measurable input-output function to any desired degree of accuracy. In this study they are used as non-linear function approximators for identifying the relationship between a number of predictor variables and the ambient temperature at the various vertical levels. An insight of the statistically derived input

  15. Ambient temperature and added heat wave effects on hospitalizations in California from 1999 to 2009.

    Science.gov (United States)

    Sherbakov, Toki; Malig, Brian; Guirguis, Kristen; Gershunov, Alexander; Basu, Rupa

    2018-01-01

    Investigators have examined how heat waves or incremental changes in temperature affect health outcomes, but few have examined both simultaneously. We utilized distributed lag nonlinear models (DLNM) to explore temperature associations and evaluate possible added heat wave effects on hospitalizations in 16 climate zones throughout California from May through October 1999-2009. We define heat waves as a period when daily mean temperatures were above the zone- and month-specific 95th percentile for at least two consecutive days. DLNMs were used to estimate climate zone-specific non-linear temperature and heat wave effects, which were then combined using random effects meta-analysis to produce an overall estimate for each. With higher temperatures, admissions for acute renal failure, appendicitis, dehydration, ischemic stroke, mental health, non-infectious enteritis, and primary diabetes were significantly increased, with added effects from heat waves observed for acute renal failure and dehydration. Higher temperatures also predicted statistically significant decreases in hypertension admissions, respiratory admissions, and respiratory diseases with secondary diagnoses of diabetes, though heat waves independently predicted an added increase in risk for both respiratory types. Our findings provide evidence that both heat wave and temperature exposures can exert effects independently. Copyright © 2017 Elsevier Inc. All rights reserved.

  16. Ambient temperature effect on pulse rate variability as an alternative to heart rate variability in young adult.

    Science.gov (United States)

    Shin, Hangsik

    2016-12-01

    Pulse rate variability (PRV) is a promising physiological and analytic technique used as a substitute for heart rate variability (HRV). PRV is measured by pulse wave from various devices including mobile and wearable devices but HRV is only measured by an electrocardiogram (ECG). The purpose of this study was to evaluate PRV and HRV at various ambient temperatures and elaborate on the interchangeability of PRV and HRV. Twenty-eight healthy young subjects were enrolled in the experiment. We prepared temperature-controlled rooms and recorded the ECG and photoplethysmography (PPG) under temperature-controlled, constant humidity conditions. The rooms were kept at 17, 25, and 38 °C as low, moderate, and high ambient temperature environments, respectively. HRV and PRV were derived from the synchronized ECG and PPG measures and they were studied in time and frequency domain analysis for PRV/HRV ratio and pulse transit time (PTT). Similarity and differences between HRV and PRV were determined by a statistical analysis. PRV/HRV ratio analysis revealed that there was a significant difference between HRV and PRV for a given ambient temperature; this was with short-term variability measures such as SDNN SDSD or RMSSD, and HF-based variables including HF, LF/HF and normalized HF. In our analysis the absolute value of PTT was not significantly influenced by temperature. Standard deviation of PTT, however, showed significant difference not only between low and moderate temperatures but also between low and high temperatures. Our results suggest that ambient temperature induces a significant difference in PRV compared to HRV and that the difference becomes greater at a higher ambient temperature.

  17. Warm ambient temperature decreases food intake in a simulated office setting: A pilot randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Molly eBernhard

    2015-08-01

    Full Text Available Background: We hypothesized that exposure to temperatures above the thermoneutral zone would decrease food intake in young adults in a sedentary office environment over a 2-hour period. Methods: Participants wearing standardized clothing were randomized to perform routine office work in either within the thermoneutral zone, considered control (19-20°C, or above the thermoneutral zone considered warmer (26-27°C treatment in parallel-group design (n=11 and 9, respectively. Thermal images of the inner canthus of their eye and middle finger nail bed, representing proxies of core and peripheral temperatures, respectively, were taken at baseline, 1st, and 2nd hour during this lunchtime study. Relative heat dissipation was estimated as peripheral temperature. General linear models were conducted to examine the effects of thermal treatment the calories intake and potential mediation. Researchers conducted the trial registered as NCT02386891 at Clinicaltrials.gov during April- May 2014. Results: During the 2 hours stay in different ambient temperatures, the participants in the control conditions ate 99.5 kcal more than those in the warmer conditions; however, the difference was not statistically significant. Female participants ate about 350 kcal less than the male participants (P=0.024 in both groups and there was no significant association between calories intake and participant’s BMI. After controlling for thermal treatment, gender and BMI, the participant’s peripheral temperature was significantly associated with calories intake (p=0.002, suggesting a mediating effect. Specifically, for every 1°C increase in peripheral temperature indicating reduced heat dissipation, participants ate 85.9 kcal less food. Conclusions: This pilot study provided preliminary evidence of effects of thermal environment on food intake and the decreased food intake in the experimental (warmer environment is potentially mediated through thermoregulatory mechanisms.

  18. Effect of ambient temperature on viral replication and serum antibody titers following administration of a commercial intranasal modified-live infectious bovine rhinotracheitis-parainfluenza-3 virus vaccine to beef cattle housed in high- and moderate-ambient temperature environments.

    Science.gov (United States)

    Grissett, Gretchen P; White, Brad J; Anderson, David E; Larson, Robert E; Miesner, Matt D

    2014-12-01

    To evaluate the effect of ambient temperature on viral replication and serum antibody titers following administration of an intranasal modified-live infectious bovine rhinotracheitis (IBR)-parainfluenza-3 (PI3) virus vaccine to beef calves housed in high- (> 32°C) and moderate- (21°C) ambient temperature environments. 28 calves (mean weight, 206.8 kg). Calves were randomly allocated to 4 treatment groups (housed outdoors during high ambient temperature with [HAT; n = 10] or without [HAC; 4] vaccination or housed indoors in a moderate ambient temperature with [MAT; 10] or without [MAC; 4] vaccination). Rectal and nasal mucosal temperatures were recorded every 2 hours from 8 AM to 8 PM on days 0 (vaccination) and 1. Nasal swab specimens were obtained on days 0 through 7 for virus isolation. Serum samples were collected on days 0, 7, 14, and 28 for determination of antibody titers. Mean rectal temperature did not differ among the treatment groups. Mean nasal temperature for the HAT group was significantly higher than that for the MAT group at 6, 24, 30, 32, and 38 hours after vaccination. Viable IBR virus was isolated from all vaccinated calves on days 1 through 6. Two weeks after vaccination, vaccinated calves had anti-IBR antibody titers that were significantly greater than those for unvaccinated calves. Mean anti-IBR antibody titers did not differ significantly between the HAT and MAT groups. Results indicated that, following vaccination with an intranasal modified-live IBR-PI3 virus vaccine, IBR viral replication and serum antibody titers did not differ significantly between calves housed in high- and moderate-ambient temperature environments.

  19. Polymer Electrolyte-Based Ambient Temperature Oxygen Microsensors for Environmental Monitoring

    Science.gov (United States)

    Hunter, Gary W.; Xu, Jennifer C.; Liu, Chung-Chiun

    2011-01-01

    An ambient temperature oxygen microsensor, based on a Nafion polymer electrolyte, has been developed and was microfabricated using thin-film technologies. A challenge in the operation of Nafion-based sensor systems is that the conductivity of Nafion film depends on the humidity in the film. Nafion film loses conductivity when the moisture content in the film is too low, which can affect sensor operation. The advancement here is the identification of a method to retain the operation of the Nafion films in lower humidity environments. Certain salts can hold water molecules in the Nafion film structure at room temperature. By mixing salts with the Nafion solution, water molecules can be homogeneously distributed in the Nafion film increasing the film s hydration to prevent Nafion film from being dried out in low-humidity environment. The presence of organics provides extra sites in the Nafion film to promote proton (H+) mobility and thus improving Nafion film conductivity and sensor performance. The fabrication of ambient temperature oxygen microsensors includes depositing basic electrodes using noble metals, and metal oxides layer on one of the electrode as a reference electrode. The use of noble metals for electrodes is due to their strong catalytic properties for oxygen reduction. A conducting polymer Nafion, doped with water-retaining components and extra sites facilitating proton movement, was used as the electrolyte material, making the design adequate for low humidity environment applications. The Nafion solution was coated on the electrodes and air-dried. The sensor operates at room temperature in potentiometric mode, which measures voltage differences between working and reference electrodes in different gases. Repeat able responses to 21-percent oxygen in nitrogen were achieved using nitrogen as a baseline gas. Detection of oxygen from 7 to 21 percent has also been demonstrated. The room-temperature oxygen micro sensor developed has extremely low power

  20. Tandem differential mobility spectrometry with ion dissociation in air at ambient pressure and temperature.

    Science.gov (United States)

    Menlyadiev, M R; Tarassov, A; Kielnecker, A M; Eiceman, G A

    2015-05-07

    Proton-bound dimers were dissociated to protonated monomers in air at ambient pressure and temperature using electric fields of ultrahigh Field Asymmetric Ion Mobility Spectrometry (ultraFAIMS) with the onset of dissociation for ethyl acetate as 96 Td and for dimethyl methyl phosphonate as 170 Td. Ions then were measured by differential mobility spectrometry (DMS). Fragment ions were formed with propyl acetate at electric fields of 90 Td or greater. The dissociation in ultraFAIMS of ions, with compensation fields near zero, to form smaller ions with new compensation fields, provided a method to improve peak capacity in DMS without gas modifiers. These findings also lay the foundation for a triple stage DMS with a centre stage for ion dissociation or fragmentation.

  1. Synthesis of ammonia directly from air and water at ambient temperature and pressure

    Science.gov (United States)

    Lan, Rong; Irvine, John T. S.; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol−1) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N2 separation and H2 production stages. A maximum ammonia production rate of 1.14 × 10−5 mol m−2 s−1 has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future. PMID:23362454

  2. Synthesis of ammonia directly from air and water at ambient temperature and pressure.

    Science.gov (United States)

    Lan, Rong; Irvine, John T S; Tao, Shanwen

    2013-01-01

    The N≡N bond (225 kcal mol⁻¹) in dinitrogen is one of the strongest bonds in chemistry therefore artificial synthesis of ammonia under mild conditions is a significant challenge. Based on current knowledge, only bacteria and some plants can synthesise ammonia from air and water at ambient temperature and pressure. Here, for the first time, we report artificial ammonia synthesis bypassing N₂ separation and H₂ production stages. A maximum ammonia production rate of 1.14 × 10⁻⁵ mol m⁻² s⁻¹ has been achieved when a voltage of 1.6 V was applied. Potentially this can provide an alternative route for the mass production of the basic chemical ammonia under mild conditions. Considering climate change and the depletion of fossil fuels used for synthesis of ammonia by conventional methods, this is a renewable and sustainable chemical synthesis process for future.

  3. Numerical analysis of composite steel-concrete beams in ambient temperature and in fire situation

    Directory of Open Access Journals (Sweden)

    Roberto Martins Gonçalves

    2005-02-01

    Full Text Available This paper presents three-dimensional numerical models of steel-concrete composite beams with full interaction (no slip between concrete slab and steel beam using a non-linear procedure. The threedimensional numerical models must be capable of predicting the response of composite beam at ambient temperature and in fire situation with accuracy. The computer program ABAQUS ® 6.3-1, based on Finite Element Method, was used to analyze the numerical modeling. The accuracy of the models is demonstrated through the results obtained, which are compared with the experimental results presented in other works. The reported results, when compared to experimental data, demonstrate that the numerical models elaborated with shell finite elements show better performance when compared to the results of the numerical models elaborated with solid finite elements.

  4. Identification of the Products of Oxidation of Quercetin by Air Oxygenat Ambient Temperature

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    Viktor A Utsal

    2007-03-01

    Full Text Available Oxidation of quercetin by air oxygen takes place in water and aqueous ethanol solutions under mild conditions, namely in moderately-basic media (pH ∼ 8-10 at ambient temperature and in the absence of any radical initiators, without enzymatic catalysis or irradiation of the reaction media by light. The principal reaction products are typical of other oxidative degradation processes of quercetin, namely 3,4-dihydroxy-benzoic (proto-catechuic and 2,4,6-trihydroxybenzoic (phloroglucinic acids, as well as the decarboxylation product of the latter – 1,3,5-trihydroxybenzene (phloroglucinol. In accordance with the literature data, this process involves the cleavage of the γ-pyrone fragment (ring C of the quercetin molecule by oxygen, with primary formation of 4,6-dihydroxy-2-(3,4-dihydroxybenzoyloxybenzoic acid (depside. However under such mild conditions the accepted mechanism of this reaction (oxidative decarbonylation with formation of carbon monoxide, CO should be reconsidered as preferably an oxidative decarboxylation with formation of carbon dioxide, CO2. Direct head-space analysis of the gaseous components formed during quercetin oxidation in aqueous solution at ambient temperature indicates that the ratio of carbon dioxide/carbon monoxide in the gas phase after acidification of the reaction media is ca. 96:4 %. Oxidation under these mild conditions is typical for other flavonols having OH groups at C3 (e.g., kaempferol, but it is completely suppressed if this hydroxyl group is substituted by a glycoside fragment (as in rutin, or a methyl substituent. An alternative oxidation mechanism involving the direct cleavage of the C2-C3 bond in the diketo-tautomer of quercetin is proposed.

  5. Lipopolysaccharide-induced neuronal activation in the paraventricular and dorsomedial hypothalamus depends on ambient temperature.

    Directory of Open Access Journals (Sweden)

    Samuel P Wanner

    Full Text Available Systemic inflammatory response syndrome is associated with either fever or hypothermia, but the mechanisms responsible for switching from one to the other are unknown. In experimental animals, systemic inflammation is often induced by bacterial lipopolysaccharide (LPS. To identify the diencephalic and brainstem structures involved in the fever-hypothermia switch, we studied the expression of c-Fos protein, a marker of neuronal activation, in rats treated with the same high dose of LPS (0.5 mg/kg, intravenously either in a thermoneutral (30 °C or cool (24 °C environment. At 30 °C, LPS caused fever; at 24 °C, the same dose caused profound hypothermia. Both fever and hypothermia were associated with the induction of c-Fos in many brain areas, including several structures of the anterior preoptic, paraventricular, lateral, and dorsal hypothalamus, the bed nucleus of the stria terminalis, the posterior pretectal nucleus, ventrolateral periaqueductal gray, lateral parabrachial nucleus, area postrema, and nucleus of the solitary tract. Every brain area studied showed a comparable response to LPS at the two different ambient temperatures used, with the exception of two areas: the dorsomedial hypothalamic nucleus (DMH, which we studied together with the adjacent dorsal hypothalamic area (DA, and the paraventricular hypothalamic nucleus (PVH. Both structures had much stronger c-Fos expression during LPS hypothermia than during fever. We propose that PVH and DMH/DA neurons are involved in a circuit, which - depending on the ambient temperature - determines whether the thermoregulatory response to bacterial LPS will be fever or hypothermia.

  6. The Burden of COPD Morbidity Attributable to the Interaction between Ambient Air Pollution and Temperature in Chengdu, China

    Directory of Open Access Journals (Sweden)

    Hang Qiu

    2018-03-01

    Full Text Available Evidence on the burden of chronic obstructive pulmonary disease (COPD morbidity attributable to the interaction between ambient air pollution and temperature has been limited. This study aimed to examine the modification effect of temperature on the association of ambient air pollutants (including particulate matter (PM with aerodynamic diameter <10 μm (PM10 and <2.5 μm (PM2.5, nitrogen dioxide (NO2, sulfur dioxide (SO2, carbon monoxide (CO and ozone (O3 with risk of hospital admissions (HAs for COPD, as well as the associated morbidity burden in urban areas of Chengdu, China, from 2015 to 2016. Based on the generalized additive model (GAM with quasi-Poisson link, bivariate response surface model and stratification parametric model were developed to investigate the potential interactions between ambient air pollution and temperature on COPD HAs. We found consistent interactions between ambient air pollutants (PM2.5, PM10 and SO2 and low temperature on COPD HAs, demonstrated by the stronger associations between ambient air pollutants and COPD HAs at low temperatures than at moderate temperatures. Subgroup analyses showed that the elderly (≥80 years and males were more vulnerable to this interaction. The joint effect of PM and low temperature had the greatest impact on COPD morbidity burden. Using WHO air quality guidelines as reference concentration, about 17.30% (95% CI: 12.39%, 22.19% and 14.72% (95% CI: 10.38%, 19.06% of COPD HAs were attributable to PM2.5 and PM10 exposures on low temperature days, respectively. Our findings suggested that low temperature significantly enhanced the effects of PM and SO2 on COPD HAs in urban Chengdu, resulting in increased morbidity burden. This evidence has important implications for developing interventions to reduce the risk effect of COPD morbidity.

  7. Short communication: Changes in body temperature of calves up to 2 months of age as affected by time of day, age, and ambient temperature.

    Science.gov (United States)

    Hill, T M; Bateman, H G; Suarez-Mena, F X; Dennis, T S; Schlotterbeck, R L

    2016-11-01

    Extensive measurements of calf body temperature are limited in the literature. In this study, body temperatures were collected by taping a data logger to the skin over the tail vein opposing the rectum of Holstein calves between 4 and 60d of age during 3 different periods of the summer and fall. The summer period was separated into moderate (21-33°C average low to high) and hot (25-37°C) periods, whereas the fall exhibited cool (11-19°C) ambient temperatures. Tail temperatures were compared in a mixed model ANOVA using ambient temperature, age of calf, and time of day (10-min increments) as fixed effects and calf as a random effect. Measures within calf were modeled as repeated effects of type autoregressive 1. Calf temperature increased 0.0325°C (±0.00035) per 1°C increase in ambient temperature. Body temperature varied in a distinct, diurnal pattern with time of day, with body temperatures being lowest around 0800h and highest between 1700 and 2200h. During periods of hot weather, the highest calf temperature was later in the day (~2200h). Calf minimum, maximum, and average body temperatures were all higher in hot than in moderate periods and higher in moderate than in cool periods. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  8. Experimental Assessment of residential split type air-conditioning systems using alternative refrigerants to R-22 at high ambient temperatures

    International Nuclear Information System (INIS)

    Joudi, Khalid A.; Al-Amir, Qusay R.

    2014-01-01

    Highlights: • R290, R407C and R410A in residential split A/C units at high ambient. • 1 and 2 TR residential air conditioners with R22 alternatives at high ambient. • Residential split unit performance at ambients up to 55 °C with R22 alternatives. - Abstract: Steady state performance of residential air conditioning systems using R22 and alternatives R290, R407C, R410A, at high ambient temperatures, have been investigated experimentally. System performance parameters such as optimum refrigerant charge, coefficient of performance, cooling capacity, power consumption, pressure ratio, power per ton of refrigeration and TEWI environmental factor have been determined. All refrigerants were tested in the cooling mode operation under high ambient air temperatures, up to 55 °C, to determine their suitability. Two split type air conditioner of 1 and 2 TR capacities were used. A psychrometric test facility was constructed consisting of a conditioned cool compartment and an environmental duct serving the condenser. Air inside the conditioned compartment was maintained at 25 °C dry bulb and 19 °C wet bulb for all tests. In the environmental duct, the ambient air temperature was varied from 35 °C to 55 °C in 5 °C increments. The study showed that R290 is the better candidate to replace R22 under high ambient air temperatures. It has lower TEWI values and a better coefficient of performance than the other refrigerants tested. It is suitable as a drop-in refrigerant. R407C has the closest performance to R22, followed by R410A

  9. State of charge estimation of lithium-ion batteries using the open-circuit voltage at various ambient temperatures

    International Nuclear Information System (INIS)

    Xing, Yinjiao; He, Wei; Pecht, Michael; Tsui, Kwok Leung

    2014-01-01

    Highlights: • An offline OCV–SOC–temperature table was established to infer battery SOC. • A temperature-based model was developed to estimate SOC at different temperatures. • The algorithm for SOC estimation was verified by dynamic current load. • The robustness of the approach was validated by different initial SOC values. - Abstract: Ambient temperature is a significant factor that influences the accuracy of battery SOC estimation, which is critical for remaining driving range prediction of electric vehicles (EVs) and optimal charge/discharge control of batteries. A widely used method to estimate SOC is based on an online inference of open-circuit voltage (OCV). However, the fact that the OCV–SOC is dependent on ambient temperature can result in errors in battery SOC estimation. To address this problem, this paper presents an SOC estimation approach based on a temperature-based model incorporated with an OCV–SOC–temperature table. The unscented Kalman filtering (UKF) was applied to tune the model parameters at each sampling step to cope with various uncertainties arising from the operation environment, cell-to-cell variation, and modeling inaccuracy. Two dynamic tests, the dynamic stress test (DST) and the federal urban driving schedule (FUDS), were used to test batteries at different temperatures. Then, DST was used to identify the model parameters while FUDS was used to validate the performance of the SOC estimation. The estimation was made covering the major working range from 25% to 85% SOC. The results indicated that our method can provide accurate SOC estimation with smaller root mean squared errors than the method that does not take into account ambient temperature. Thus, our approach is effective and accurate when battery operates at different ambient temperatures. Since the developed method takes into account the temperature factor as well as the complexity of the model, it could be effectively applied in battery management systems for

  10. Low ambient temperature elevates plasma triiodothyronine concentrations while reducing digesta mean retention time and methane yield in sheep.

    Science.gov (United States)

    Barnett, M C; McFarlane, J R; Hegarty, R S

    2015-06-01

    Ruminant methane yield (MY) is positively correlated with mean retention time (MRT) of digesta. The hormone triiodothyronine (T3 ), which is negatively correlated with ambient temperature, is known to influence MRT. It was hypothesised that exposing sheep to low ambient temperatures would increase plasma T3 concentration and decrease MRT of digesta within the rumen of sheep, resulting in a reduction of MY. To test this hypothesis, six Merino sheep were exposed to two different ambient temperatures (cold treatment, 9 ± 1 °C; warm control 26 ± 1 °C). The effects on MY, digesta MRT, plasma T3 concentration, CO2 production, DM intake, DM digestibility, change in body weight (BW), rumen volatile fatty acid (VFA) concentrations, estimated microbial protein output, protozoa abundance, wool growth, water intake, urine output and rectal temperature were studied. Cold treatment resulted in a reduction in MY (p sheep to cold ambient temperatures reduces digesta retention time in the gastrointestinal tract, leading to a reduction in enteric methane yield. Further research is warranted to determine whether T3 could be used as an indirect selection tool for genetic selection of low enteric methane-producing ruminants. Journal of Animal Physiology and Animal Nutrition © 2014 Blackwell Verlag GmbH.

  11. Effects of reproductive status and high ambient temperatures on the body temperature of a free-ranging basoendotherm.

    Science.gov (United States)

    Levesque, Danielle L; Lobban, Kerileigh D; Lovegrove, Barry G

    2014-12-01

    Tenrecs (Order Afrosoricida) exhibit some of the lowest body temperatures (T b) of any eutherian mammal. They also have a high level of variability in both active and resting T bs and, at least in cool temperatures in captivity, frequently employ both short- and long-term torpor. The use of heterothermy by captive animals is, however, generally reduced during gestation and lactation. We present data long-term T b recordings collected from free-ranging S. setosus over the course of two reproductive seasons. In general, reproductive females had slightly higher (~32 °C) and less variable T b, whereas non-reproductive females and males showed both a higher propensity for torpor as well as lower (~30.5 °C) and more variable rest-phase T bs. Torpor expression defined using traditional means (using a threshold or cut-off T b) was much lower than predicted based on the high degree of heterothermy in captive tenrecs. However, torpor defined in this manner is likely to be underestimated in habitats where ambient temperature is close to T b. Our results caution against inferring metabolic states from T b alone and lend support to the recent call to define torpor in free-ranging animals based on mechanistic and not descriptive variables. In addition, lower variability in T b observed during gestation and lactation confirms that homeothermy is essential for reproduction in this species and probably for basoendothermic mammals in general. The relatively low costs of maintaining homeothermy in a sub-tropical environment might help shed light on how homeothermy could have evolved incrementally from an ancestral heterothermic condition.

  12. Test Standard Developed for Determining the Slow Crack Growth of Advanced Ceramics at Ambient Temperature

    Science.gov (United States)

    Choi, Sung R.; Salem, Jonathan A.

    1998-01-01

    The service life of structural ceramic components is often limited by the process of slow crack growth. Therefore, it is important to develop an appropriate testing methodology for accurately determining the slow crack growth design parameters necessary for component life prediction. In addition, an appropriate test methodology can be used to determine the influences of component processing variables and composition on the slow crack growth and strength behavior of newly developed materials, thus allowing the component process to be tailored and optimized to specific needs. At the NASA Lewis Research Center, work to develop a standard test method to determine the slow crack growth parameters of advanced ceramics was initiated by the authors in early 1994 in the C 28 (Advanced Ceramics) committee of the American Society for Testing and Materials (ASTM). After about 2 years of required balloting, the draft written by the authors was approved and established as a new ASTM test standard: ASTM C 1368-97, Standard Test Method for Determination of Slow Crack Growth Parameters of Advanced Ceramics by Constant Stress-Rate Flexural Testing at Ambient Temperature. Briefly, the test method uses constant stress-rate testing to determine strengths as a function of stress rate at ambient temperature. Strengths are measured in a routine manner at four or more stress rates by applying constant displacement or loading rates. The slow crack growth parameters required for design are then estimated from a relationship between strength and stress rate. This new standard will be published in the Annual Book of ASTM Standards, Vol. 15.01, in 1998. Currently, a companion draft ASTM standard for determination of the slow crack growth parameters of advanced ceramics at elevated temperatures is being prepared by the authors and will be presented to the committee by the middle of 1998. Consequently, Lewis will maintain an active leadership role in advanced ceramics standardization within ASTM

  13. Ambient Temperature Flotation of Sedimentary Phosphate Ore Using Cottonseed Oil as a Collector

    Directory of Open Access Journals (Sweden)

    Yaoyang Ruan

    2017-04-01

    Full Text Available The mid-low grade sedimentary phosphate ore, abundant in silicate and carbonate gangue minerals, exhibits a poor processability. It is conventionally enriched using high temperature flotation to remove silicate gangues with fatty acid as a collector. Cottonseed oil has been proved to be an efficient collector for achieving ambient temperature flotation of the sedimentary phosphate ore used in this study. Flotation kinetics was investigated to ascertain the excellent collecting performance of cottonseed oil, as compared with oleic acid, and the phosphate flotation fitted well with the first-order flotation model. Based on the analysis of flotation reagent effect on the direct flotation process using the response surface methodology (RSM, a closed circuit of direct-reverse flotation for stepwise removing silicate and carbonate gangues from the sedimentary phosphate ore was established. Consequently, a required high quality of phosphate concentrate containing 30.16% P2O5 was obtained, with a recovery of 90.90%. Scanning electron microscopy (SEM and X-ray diffraction analysis (XRD of the flotation products confirmed that the majority of silicate and carbonate gangues were effectively removed from the concentrate products.

  14. Enrichment of denitrifying methanotrophic bacteria from Taihu sediments by a membrane biofilm bioreactor at ambient temperature.

    Science.gov (United States)

    Wang, Shenghui; Wu, Qing; Lei, Ting; Liang, Peng; Huang, Xia

    2016-03-01

    Denitrification coupled to anaerobic methane oxidation is a recently discovered process performed by bacteria affiliated to the NC10 phylum. These microorganisms could play important roles in the energy-efficient way of anaerobic wastewater treatment where residual dissolved methane might be removed at the expense of nitrate or nitrite. The difficulty to enrich these microorganisms due to a slow growth rate, especially at low temperatures, limited its application in engineering field. In this study, an NC10 bacteria community was enriched from Taihu sediments by a membrane biofilm bioreactor at ambient temperature of 10-25 °C. After 13 months enrichment, the maximum denitrification rate of the enriched culture reached 0.54 mM day(-1) for nitrate and 1.06 mM day(-1) for nitrite. Anaerobic methane oxidation coupled denitrification was estimated from the (13)C-labeled CO2 ((13)CO2) production during batch incubations with (13)CH4. Furthermore, analysis of 16S rRNA genes clone library confirmed the presence of NC10 phylum bacteria and fluorescence in situ hybridization showed that NC10 bacteria dominated the reactor. All of the results indicated the NC10 bacteria community was competitive in terms of treating nitrate-contaminated water or wastewater under natural conditions.

  15. Screening of agrochemicals in foodstuffs using low-temperature plasma (LTP) ambient ionization mass spectrometry.

    Science.gov (United States)

    Wiley, Joshua S; García-Reyes, Juan F; Harper, Jason D; Charipar, Nicholas A; Ouyang, Zheng; Cooks, R Graham

    2010-05-01

    Low-temperature plasma (LTP) permits direct ambient ionization and mass analysis of samples in their native environment with minimal or no prior preparation. LTP utilizes dielectric barrier discharges (DBDs) to create a low power plasma which is guided by gas flow onto the sample from which analytes are desorbed and ionized. In this study, the potential of LTP-MS for the detection of pesticide residues in food is demonstrated. Thirteen multi-class agricultural chemicals were studied (ametryn, amitraz, atrazine, buprofezin, DEET, diphenylamine, ethoxyquin, imazalil, isofenphos-methyl, isoproturon, malathion, parathion-ethyl and terbuthylazine). To evaluate the potential of the proposed approach, LTP-MS experiments were performed directly on fruit peels as well as on fruit/vegetable extracts. Most of the agrochemicals examined displayed remarkable sensitivity in the positive ion mode, giving limits of detection (LOD) for the direct measurement in the low picogram range. Tandem mass spectrometry (MS/MS) was used to confirm identification of selected pesticides by using for these experiments spiked fruit/vegetable extracts (QuEChERS, a standard sample treatment protocol) at levels as low as 1 pg, absolute, for some of the analytes. Comparisons of the data obtained by direct LTP-MS were made with the slower but more accurate conventional LC-MS/MS procedure. Herbicides spiked in aqueous solutions were detectable at LODs as low as 0.5 microg L(-1) without the need for any sample preparation. The results demonstrate that ambient LTP-MS can be applied for the detection and confirmation of traces of agrochemicals in actual market-purchased produce and in natural water samples. Quantitative analysis was also performed in a few selected cases and displayed a relatively high degree of linearity over four orders of magnitude.

  16. 40 CFR Appendix H to Part 50 - Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 2 2010-07-01 2010-07-01 false Interpretation of the 1-Hour Primary and Secondary National Ambient Air Quality Standards for Ozone H Appendix H to Part 50 Protection of... AIR QUALITY STANDARDS Pt. 50, App. H Appendix H to Part 50—Interpretation of the 1-Hour Primary and...

  17. Direct Observations of Isoprene Secondary Organic Aerosol Formation in Ambient Cloud Droplets

    Science.gov (United States)

    Zelenyuk, A.; Bell, D.; Thornton, J. A.; Fast, J. D.; Shrivastava, M. B.; Berg, L. K.; Imre, D. G.; Mei, F.; Shilling, J.; Suski, K. J.; Liu, J.; Tomlinson, J. M.; Wang, J.

    2017-12-01

    Multiphase chemistry of isoprene photooxidation products has been shown to be one of the major sources of secondary organic aerosol (SOA) in the atmosphere. A number of recent studies indicate that aqueous aerosol phase provides a medium for reactive uptake of isoprene photooxidation products, and in particular, isomeric isoprene epoxydiols (IEPOX), with reaction rates and yields being dependent on aerosol acidity, water content, sulfate concentration, and organic coatings. However, very few studies focused on chemistry occurring within actual cloud droplets. We will present data acquired during recent Holistic Interactions of Shallow Clouds, Aerosols, and Land Ecosystems (HI-SCALE) Campaign, which provide direct evidence for IEPOX-SOA formation in cloud droplets. Single particle mass spectrometer, miniSPLAT, and a high-resolution, time-of-flight aerosol mass spectrometer were used to characterize the composition of aerosol particles and cloud droplet residuals, while a high-resolution, time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) was used to characterize gas-phase compounds. We find that the composition of cloud droplet residuals was markedly different than that of aerosol particles sampled outside the cloud. Cloud droplet residuals were comprised of individual particles with high relative fractions of sulfate and nitrate and significant fraction of particles with mass spectra that are nearly identical to those of laboratory-generated IEPOX-SOA particles. The observed cloud-induced formation of IEPOX-SOA was accompanied by simultaneous decrease in measured concentrations of IEPOX and other gas-phase isoprene photooxidation products. Ultimately, the combined cloud, aerosol, and gas-phase measurements conducted during HI-SCALE will be used to develop and evaluate model treatments of aqueous-phase isoprene SOA formation.

  18. High ambient temperature increases 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy")-induced Fos expression in a region-specific manner.

    Science.gov (United States)

    Hargreaves, G A; Hunt, G E; Cornish, J L; McGregor, I S

    2007-03-16

    3,4-Methylenedioxymethamphetamine (MDMA, "Ecstasy") is a popular drug that is often taken under hot conditions at dance clubs. High ambient temperature increases MDMA-induced hyperthermia and recent studies suggest that high temperatures may also enhance the rewarding and prosocial effects of MDMA in rats. The present study investigated whether ambient temperature influences MDMA-induced expression of Fos, a marker of neural activation. Male Wistar rats received either MDMA (10 mg/kg i.p.) or saline, and were placed in test chambers for 2 h at either 19 or 30 degrees C. MDMA caused significant hyperthermia at 30 degrees C and a modest hypothermia at 19 degrees C. The 30 degrees C ambient temperature had little effect on Fos expression in vehicle-treated rats. However MDMA-induced Fos expression was augmented in 15 of 30 brain regions at the high temperature. These regions included (1) sites associated with thermoregulation such as the median preoptic nucleus, dorsomedial hypothalamus and raphe pallidus, (2) the supraoptic nucleus, a region important for osmoregulation and a key mediator of oxytocin and vasopressin release, (3) the medial and central nuclei of the amygdala, important in the regulation of social and emotional behaviors, and (4) the shell of the nucleus accumbens and (anterior) ventral tegmental area, regions associated with the reinforcing effects of MDMA. MDMA-induced Fos expression was unaffected by ambient temperature at many other sites, and was diminished at high temperature at one site (the islands of Calleja), suggesting that the effect of temperature on MDMA-induced Fos expression was not a general pharmacokinetic effect. Overall, these results indicate that high temperatures accentuate key neural effects of MDMA and this may help explain the widespread use of the drug under hot conditions at dance parties as well as the more hazardous nature of MDMA taken under such conditions.

  19. Sloths like it hot: ambient temperature modulates food intake in the brown-throated sloth (Bradypus variegatus

    Directory of Open Access Journals (Sweden)

    Rebecca N. Cliffe

    2015-04-01

    Full Text Available Sloths are considered to have one of the lowest mass-specific metabolic rates of any mammal and, in tandem with a slow digestive rate, have been theorized to have correspondingly low rates of ingestion. Here, we show in a study conducted over five months, that three captive Bradypus variegatus (Brown-throated sloths had a remarkably low mean food intake of 17 g kg−1day−1 (SD 4.2. Food consumption was significantly affected by ambient temperature, with increased intake at higher temperatures. We suggest that the known fluctuation of sloth core body temperature with ambient temperature affects the rate at which gut fauna process digesta, allowing for increased rates of fermentation at higher temperatures. Since Bradypus sloths maintain a constantly full stomach, faster rates of fermentation should enhance digestive throughput, increasing the capacity for higher levels of food intake, thereby allowing increased energy acquisition at higher ambient temperatures. This contrasts with other mammals, which tend to show increased levels of food intake in colder conditions, and points to the importance of temperature in regulating all aspects of energy use in sloths.

  20. Sloths like it hot: ambient temperature modulates food intake in the brown-throated sloth (Bradypus variegatus).

    Science.gov (United States)

    Cliffe, Rebecca N; Haupt, Ryan J; Avey-Arroyo, Judy A; Wilson, Rory P

    2015-01-01

    Sloths are considered to have one of the lowest mass-specific metabolic rates of any mammal and, in tandem with a slow digestive rate, have been theorized to have correspondingly low rates of ingestion. Here, we show in a study conducted over five months, that three captive Bradypus variegatus (Brown-throated sloths) had a remarkably low mean food intake of 17 g kg(-1)day(-1) (SD 4.2). Food consumption was significantly affected by ambient temperature, with increased intake at higher temperatures. We suggest that the known fluctuation of sloth core body temperature with ambient temperature affects the rate at which gut fauna process digesta, allowing for increased rates of fermentation at higher temperatures. Since Bradypus sloths maintain a constantly full stomach, faster rates of fermentation should enhance digestive throughput, increasing the capacity for higher levels of food intake, thereby allowing increased energy acquisition at higher ambient temperatures. This contrasts with other mammals, which tend to show increased levels of food intake in colder conditions, and points to the importance of temperature in regulating all aspects of energy use in sloths.

  1. Staying cool in a changing landscape: the influence of maximum daily ambient temperature on grizzly bear habitat selection.

    Science.gov (United States)

    Pigeon, Karine E; Cardinal, Etienne; Stenhouse, Gordon B; Côté, Steeve D

    2016-08-01

    To fulfill their needs, animals are constantly making trade-offs among limiting factors. Although there is growing evidence about the impact of ambient temperature on habitat selection in mammals, the role of environmental conditions and thermoregulation on apex predators is poorly understood. Our objective was to investigate the influence of ambient temperature on habitat selection patterns of grizzly bears in the managed landscape of Alberta, Canada. Grizzly bear habitat selection followed a daily and seasonal pattern that was influenced by ambient temperature, with adult males showing stronger responses than females to warm temperatures. Cutblocks aged 0-20 years provided an abundance of forage but were on average 6 °C warmer than mature conifer stands and 21- to 40-year-old cutblocks. When ambient temperatures increased, the relative change (odds ratio) in the probability of selection for 0- to 20-year-old cutblocks decreased during the hottest part of the day and increased during cooler periods, especially for males. Concurrently, the probability of selection for 21- to 40-year-old cutblocks increased on warmer days. Following plant phenology, the odds of selecting 0- to 20-year-old cutblocks also increased from early to late summer while the odds of selecting 21- to 40-year-old cutblocks decreased. Our results demonstrate that ambient temperatures, and therefore thermal requirements, play a significant role in habitat selection patterns and behaviour of grizzly bears. In a changing climate, large mammals may increasingly need to adjust spatial and temporal selection patterns in response to thermal constraints.

  2. Association between ambient carbon monoxide and secondary hyperparathyroidism in nondiabetic patients undergoing peritoneal dialysis

    Directory of Open Access Journals (Sweden)

    Weng CH

    2015-09-01

    Full Text Available Cheng-Hao Weng,1,2 Ching-Chih Hu,3 Tzung-Hai Yen,1,2 Wen-Hung Huang1,2 1Department of Nephrology, Division of Clinical Toxicology, Chang Gung Memorial Hospital, Linkou, 2College of Medicine, Chang Gung University, Taoyuan, 3Liver Research Unit, Department of Hepatogastroenterology, Chang Gung Memorial Hospital, Keelung, Taiwan Background: Secondary hyperparathyroidism (SHPT is a major disorder in patients with chronic renal disease with or without dialysis. Air pollution has been confirmed as being associated with increased incidence of human morbidity and mortality. To our knowledge, investigating air pollution as a dialysis-unrelated factor for SHPT in patients undergoing dialysis is limited. We developed this study to assess the effect of air pollution and other important risk factors on SHPT in patients undergoing peritoneal dialysis (PD. Materials and methods: We recruited a total of 141 patients who did not have diabetes mellitus, were nonsmokers, and were undergoing PD in this cross-sectional study. We analyzed the difference in air quality based on the patients’ living areas. We estimated demographic, hematological, nutritional, inflammatory, biochemical, air pollutant, and dialysis-related data based on this cross-sectional study. Subgroup analysis of the relationship between air pollutants and the clinical variables and having or not having hyperparathyroidism (HPT (intact parathyroid hormone level ≥180 pg/dL was also performed. Results: A total of 141 patients undergoing PD (30 men and 111 women were enrolled in the study. Sixty-eight patients had SHPT. In a binary logistic regression, high environmental CO exposure (odds ratio [OR] 3.22, 95% confidence interval [CI] 1.42–7.28; P=0.005, serum phosphate levels (OR 1.66, 95% CI 1.17–2.37; P=0.005, hypoalbuminemia (OR 3.76, 95% CI 1.29–10.94; P=0.015, and use of calcitriol (OR 8.25, 95% CI 3.43–19.85; P<0.001 were positively associated with SHPT. Conclusion: The findings of

  3. Individual variation in metabolic reaction norms over ambient temperature causes low correlation between basal and standard metabolic rate

    NARCIS (Netherlands)

    Briga, Michael; Verhulst, Simon

    2017-01-01

    Basal metabolic rate (BMR) is often assumed to be indicative of the energy turnover at ambient temperatures (T-a) below the thermoneutral zone (SMR), but this assumption has remained largely untested. Using a new statistical approach, we quantified the consistency in nocturnal metabolic rate across

  4. Synchronous Crepuscular Flight of Female Asian Gypsy Moths: Relationships of Light Intensity and Ambient and Body Temperatures

    Science.gov (United States)

    Ralph E. Charlton; Ring T. Carde; William E. Wallner; William E. Wallner

    1999-01-01

    Female gypsy moths (Lymantria dispar) of Asian heritage studied in central Siberia and Germany exhibit a highly synchronous flight at dusk, after light intensity falls to about 2 lux. This critical light intensity sets the timing of flight behaviors independent of ambient temperature. Flight follows several minutes of preflight wing fanning during which females in...

  5. Effects of ambient temperature and soybean meal supplementation on intake and digestion of two sheep breeds differing in mature size

    NARCIS (Netherlands)

    Lourenço, A.L.; Cone, J.W.; Fontes, P.; Dias-Da-Silva, A.

    2010-01-01

    The aim of this study was to compare the intake and digestive physiology of mature ewes of two breeds - Ile-de-France (mature weight: 75–80 kg) and Churra-da-Terra-Quente (CTQ; mature weight: 45–50 kg) - and evaluate the effects of ambient temperature and protein supplementation in the comparison.

  6. Effect of Sodium Bicarbonate Supplementation on Carcass Characteristics of Lambs Fed Concentrate Diets at Different Ambient Temperature Levels

    Directory of Open Access Journals (Sweden)

    Demba B. Jallow

    2014-08-01

    Full Text Available The objective of this study was to investigate the influence of ambient temperatures on carcass characteristics of lambs fed concentrate diets with or without NaHCO3 supplementation. A slaughter study was carried on 12 male Black Belly Barbados lambs randomly drawn from a growth trial (35 weeks. The lambs were divided into four equal groups and allotted in a 2×2 factorial design. The lambs were allotted at random to two dietary treatments of a basal diet (35:65 roughage:concentrate or basal diet supplemented with 4% NaHCO3 at different ambient temperatures (20°C and 30°C in an environment controlled chamber for 10 days. Lambs were slaughtered for carcass evaluation at about 262 days of age (245 days of growth trial, 7 days adaptation and 10 days of experimental period. Ambient temperature had significant (p0.05 effects on pH, and water holding capacity on both muscles. These results indicated that NaHCO3 supplementation at low ambient temperatures had caused an increase in carcass characteristics leading to significant effect on meat quality.

  7. A new predictive dynamic model describing the effect of the ambient temperature and the convective heat transfer coefficient on bacterial growth.

    Science.gov (United States)

    Ben Yaghlene, H; Leguerinel, I; Hamdi, M; Mafart, P

    2009-07-31

    In this study, predictive microbiology and food engineering were combined in order to develop a new analytical model predicting the bacterial growth under dynamic temperature conditions. The proposed model associates a simplified primary bacterial growth model without lag, the secondary Ratkowsky "square root" model and a simplified two-parameter heat transfer model regarding an infinite slab. The model takes into consideration the product thickness, its thermal properties, the ambient air temperature, the convective heat transfer coefficient and the growth parameters of the micro organism of concern. For the validation of the overall model, five different combinations of ambient air temperature (ranging from 8 degrees C to 12 degrees C), product thickness (ranging from 1 cm to 6 cm) and convective heat transfer coefficient (ranging from 8 W/(m(2) K) to 60 W/(m(2) K)) were tested during a cooling procedure. Moreover, three different ambient air temperature scenarios assuming alternated cooling and heating stages, drawn from real refrigerated food processes, were tested. General agreement between predicted and observed bacterial growth was obtained and less than 5% of the experimental data fell outside the 95% confidence bands estimated by the bootstrap percentile method, at all the tested conditions. Accordingly, the overall model was successfully validated for isothermal and dynamic refrigeration cycles allowing for temperature dynamic changes at the centre and at the surface of the product. The major impact of the convective heat transfer coefficient and the product thickness on bacterial growth during the product cooling was demonstrated. For instance, the time needed for the same level of bacterial growth to be reached at the product's half thickness was estimated to be 5 and 16.5 h at low and high convection level, respectively. Moreover, simulation results demonstrated that the predicted bacterial growth at the air ambient temperature cannot be assumed to be

  8. Individual variation in metabolic reaction norms over ambient temperature causes low correlation between basal and standard metabolic rate

    OpenAIRE

    Briga, Michael; Verhulst, Simon

    2017-01-01

    Basal metabolic rate (BMR) is often assumed to be indicative of the energy turnover at ambient temperatures (T-a) below the thermoneutral zone (SMR), but this assumption has remained largely untested. Using a new statistical approach, we quantified the consistency in nocturnal metabolic rate across a temperature range in zebra finches (N=3213 measurements on 407 individuals) living permanently in eight outdoor aviaries. Foraging conditions were either benign or harsh, and body mass and mass-a...

  9. Effects of PCM on power consumption and temperature control performance of a thermal control system subject to periodic ambient conditions

    International Nuclear Information System (INIS)

    Ye, Hong; Wang, Zijun; Wang, Liwei

    2017-01-01

    Highlights: • Phase change thermal control with under periodic ambient condition was studied. • Influences of PCM on thermal control effects were explored. • The simulated results agreed well with the experimental results. • Conditions of achieving the optimal thermal control effects were proposed. • An optimal phase change range can be obtained according to TMY data. - Abstract: Thermal control systems operating under periodic outdoor ambient conditions have numerous important applications in industrial fields. Reducing system energy consumption and enhancing temperature control effects are crucial to improving the performance of these systems. To this end, the application of phase change material (PCM) in the envelope of a thermal control system was investigated through experiment and simulation. A simulation model of an active ventilated thermal control system was constructed and verified with experimental results, and the influences of PCM incorporated in the envelope on the power consumption and temperature control effects were discussed in two time scales. The results for typical meteorological days indicate that excellent thermal control effects can be achieved when the phase change range of PCM brackets the temperature control setpoint and is consistent with the fluctuation range of the ambient temperature. The results for a typical meteorological year (TMY) demonstrate that an optimal phase change range can be determined according to TMY data to realize the optimal thermal control effects of PCM. When the required temperature control setpoint is not within the optimal phase change range, the phase change range bracketing the temperature control setpoint is recommended.

  10. Water quality comparison of secondary effluent and reclaimed water to ambient river water of southern Okinawa Island via biological evaluation.

    Science.gov (United States)

    Mano, Hiroyuki; Takeda, Fumihiko; Kitamura, Tomokazu; Okamoto, Seiichiro; Suzuki, Yutaka; Park, Chang-Beom; Yasui, Nobuhito; Kobayashi, Kentarou; Tanaka, Yuji; Yamashita, Naoyuki; Minamiyama, Mizuhiko

    2017-08-08

    The objective of this work was to evaluate the biological effect of the secondary effluent (SE) of a wastewater treatment plant and reclaimed water treated via ultrafiltration (UF) followed by either reverse osmosis (RO) membrane filtration or nanofiltration (NF) to be used for environmental use by comparing the results of algal growth inhibition tests of concentrated samples of the SE and permeates of RO and NF with those of six rivers in southern Okinawa Island. Although the SE water had no adverse effects on the growth of the algae Pseudokirchneriella subcapitata, it could lead to water quality degradation of rivers in terms of its toxic unit value, whereas the use of RO and NF permeates would not lead to such degradation. The recharge of rivers, into which domestic wastewater and livestock effluents might be discharged in southern Okinawa Island, with reclaimed water subjected to advanced treatment could dilute the concentrations of chemicals that cause biological effects and improve the water quality of the rivers, based on the results of the bioassay using P. subcapitata. Comparing the results of bioassays of reclaimed water with those of the ambient water at a site might be effective in assessing the water quality of reclaimed water for environmental use at the site.

  11. Adsorptive removal of sulfur compounds using IRMOF-3 at ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiao-Ling [Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024 (China); Fan, Hui-Ling, E-mail: fanhuiling@tyut.edu.cn [Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024 (China); Tian, Zhen [Shanghai Second Polytechnic University, Shanghai 201209 (China); He, En-Yun; Li, Ye; Shangguan, Ju [Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024 (China)

    2014-01-15

    Zinc-based metal–organic framework (IRMOF-3) was used as adsorbent for removal of dimethyl sulfide, ethyl mercaptan and hydrogen sulfide in fixed bed reactor at ambient temperature. These samples before and after exposure to sulfur compounds were characterized by Fourier transform infrared (FTIR), and X-ray diffraction (XRD), and thermo gravimetric (TG), and X-ray photoelectron spectroscopy (XPS). The results show that IRMOF-3 exhibit the best performance for hydrogen sulfide removal with the highest breakthrough sulfur capacity, followed by ethyl mercaptan and dimethyl sulfide. This is in consistent with the interaction strength between IRMOF-3 and sulfur compounds. In the case of dimethyl sulfide and ethyl mercaptan, the interaction comes from the weak interaction between the amino group in the MOFs and the sulfur atom of the adsorbate. This can also be considered as a hydrogen bond complex in which the amino group in the MOFs and the S atom of the sulfur compounds play the role of H-donor and H-acceptor, respectively. In the case of hydrogen sulfide, the interaction with sulfur atom originates from the amino group and zinc site in the MOFs. The former is more like an acid–base interaction, whereas the latter results in new products of ZnS and H{sub 2}O and serious destruction of the MOFs.

  12. Adsorptive removal of sulfur compounds using IRMOF-3 at ambient temperature

    Science.gov (United States)

    Wang, Xiao-Ling; Fan, Hui-Ling; Tian, Zhen; He, En-Yun; Li, Ye; Shangguan, Ju

    2014-01-01

    Zinc-based metal-organic framework (IRMOF-3) was used as adsorbent for removal of dimethyl sulfide, ethyl mercaptan and hydrogen sulfide in fixed bed reactor at ambient temperature. These samples before and after exposure to sulfur compounds were characterized by Fourier transform infrared (FTIR), and X-ray diffraction (XRD), and thermo gravimetric (TG), and X-ray photoelectron spectroscopy (XPS). The results show that IRMOF-3 exhibit the best performance for hydrogen sulfide removal with the highest breakthrough sulfur capacity, followed by ethyl mercaptan and dimethyl sulfide. This is in consistent with the interaction strength between IRMOF-3 and sulfur compounds. In the case of dimethyl sulfide and ethyl mercaptan, the interaction comes from the weak interaction between the amino group in the MOFs and the sulfur atom of the adsorbate. This can also be considered as a hydrogen bond complex in which the amino group in the MOFs and the S atom of the sulfur compounds play the role of H-donor and H-acceptor, respectively. In the case of hydrogen sulfide, the interaction with sulfur atom originates from the amino group and zinc site in the MOFs. The former is more like an acid-base interaction, whereas the latter results in new products of ZnS and H2O and serious destruction of the MOFs.

  13. Examination of design options for 35 Ah ambient temperature Li-TiS sub 2 cells

    Science.gov (United States)

    Shen, D. H.; Rao, S. S.; Yen, S. P. S.; Somoano, R. B.

    1986-01-01

    The Jet Propulsion Laboratory is actively engaged in the development of ambient temperature rechargable lithium cells for future NASA geosynchronous Earth orbit (GEO) missions. To achieve these ambitious goals, Li-TiS2, Li-MoS3, and Li-V6O13 systems were examined in detail. Among these three, the Li-TiS2 system has shown the longest life cycle and highest rate capability. Experimental Li-TiS2 batteries (10.5 V, 0.4 Ah) developed in-house have completed eight simulated and accelerated GEO seasons successfully. Inview of the encouraging results, the design options were examined for a scaled-up Li-TiS2 cell. It is hoped that the results of these studies will provide guidelines for prioritizing the research efforts and guiding the selection of optimized materials. Designs for 35 Ah Li-TiS2 cell were examined because present day geosynchronous satellites are powered by batteries of 35 Ah capacity. A computer program was developed to evaluate the influence of various design parameters on the specific energy and the rate capability of the cells.

  14. Effect of ambient temperature on phenotype and functions of professional phagocytes of athymic nude mice.

    Science.gov (United States)

    Vetvicka, V; Holub, M; Houstek, J

    1993-02-01

    Cytofluorometric analysis of surface marker expression was performed on myeloid cells isolated from bone marrow, spleen and lymph nodes of nude mice and nu/+ and +/+ mice (haired controls) exposed for various time periods to ambient temperature of 22 degrees C or 28 degrees C. A rise in the proportion of cells bearing macrophage markers (MAC-1, MAC-3 and F4/80) in the spleen and of FcR+ cells in all tissues tested was found in 22 degrees C-exposed nudes with high nonshivering thermogenesis. Numbers of MAC-1+ macrophages and actively phagocytic cells increased also in peritoneal exudates. There was a conspicuous predominance of large macrophages in the exudates and the specific markers decreased in density on their surface. Ia expression declined in all tissues tested with the length of exposure to cold. In the granulocytic series (BP-2+ cells), there was a decrease in the bone marrow and lymph nodes and an increase in the spleen and circulation, which suggested an enhanced mobilization and increased production at extramedullary sites in cold-exposed nude mice. The changes in haired mice were negligible.

  15. Catalytic oxidation of low-concentration CO at ambient temperature over supported Pd-Cu catalysts.

    Science.gov (United States)

    Wang, Fagen; Zhang, Haojie; He, Dannong

    2014-01-01

    The CO catalytic oxidation at ambient temperature and high space velocity was studied over the Pd-Cu/MOx (MOx = TiO2 and AI203) catalysts. The higher Brunauer-Emmett-Teller area surface of the A1203 support facilitates the dispersion of Pd2+ species, and the presence of Cu2Cl(OH)3 accelerates the re-oxidation of Pd0 to Pd2+ over the Pd-Cu/Al203 catalyst, which contributed to better performance of CO catalytic oxidation. The poorer activity of the Pd-Cu/TiO2 catalyst was attributed to the lower dispersion of Pd2+ species because of the less surface area and the non-formation of Cu2CI(OH)3 species. The presence of saturated moisture showed a negative effect on CO conversion over the two catalysts. This might be because of the competitive adsorption, the formation of carbonate species and the transformation of Cu2CI(OH)3 to inactive CuCI over the Pd-Cu/AI2O3 catalyst, which facilitates the aggregation of PdO species over the Pd-Cu/TiO2 catalyst under the moisture condition.

  16. Short-term preservation of porcine oocytes in ambient temperature: novel approaches.

    Directory of Open Access Journals (Sweden)

    Cai-Rong Yang

    Full Text Available The objective of this study was to evaluate the feasibility of preserving porcine oocytes without freezing. To optimize preservation conditions, porcine cumulus-oocyte complexes (COCs were preserved in TCM-199, porcine follicular fluid (pFF and FCS at different temperatures (4°C, 20°C, 25°C, 27.5°C, 30°C and 38.5°C for 1 day, 2 days or 3 days. After preservation, oocyte morphology, germinal vesicle (GV rate, actin cytoskeleton organization, cortical granule distribution, mitochondrial translocation and intracellular glutathione level were evaluated. Oocyte maturation was indicated by first polar body emission and spindle morphology after in vitro culture. Strikingly, when COCs were stored at 27.5°C for 3 days in pFF or FCS, more than 60% oocytes were still arrested at the GV stage and more than 50% oocytes matured into MII stages after culture. Almost 80% oocytes showed normal actin organization and cortical granule relocation to the cortex, and approximately 50% oocytes showed diffused mitochondria distribution patterns and normal spindle configurations. While stored in TCM-199, all these criteria decreased significantly. Glutathione (GSH level in the pFF or FCS group was higher than in the TCM-199 group, but lower than in the non-preserved control group. The preserved oocytes could be fertilized and developed to blastocysts (about 10% with normal cell number, which is clear evidence for their retaining the developmental potentiality after 3d preservation. Thus, we have developed a simple method for preserving immature pig oocytes at an ambient temperature for several days without evident damage of cytoplasm and keeping oocyte developmental competence.

  17. Extended storage of gamma-irradiated mango at tropical ambient temperature by film wrap packaging

    International Nuclear Information System (INIS)

    Janave, Machhindra T.; Sharma, A.

    2005-01-01

    Low dose gamma-irradiation of pre-climacteric mango (Mangifera indica L var.'Alphonso') fruits at 100 Gy extended the shelf-life at ambient temperature (28-32 degC) by 5-6 days. The extension of shelf-life was dose dependent, maximum being at 200 Gy by about 8-10 days. Wrapping the fruits in food grade Klin Wrap film resulted in more number of fruits remaining in semiripe condition after 21 days of storage as revealed by colour of the fruits, texture, TSS, pH, acidity and vitamin C content. The fruits retained about 40% of chlorophyll however, unwrapped fruits were complete yellow. Physiological weight loss (PWL) was reduced by 50% in Klin film wrapped fruits as compared to that in unwrapped fruits. More than 70-80% fruits remained as marketable fruits at the end of experiment when control fruits were slightly overripe. The shelf-life in Klin film wrapped irradiated mangoes was extended by about 10-15 days over irradiated unwrapped fruits resulting in total shelf-life of about 25-30 days at room temperature. In mangoes of variety 'Dasheri', gamma-irradiation extended the shelf-life by 4-5 days, which could be increased further, by another 7-10 days by Klin wrap packaging. These fruits also remained green at the end of experiment, confirming the observations with 'Alphonso' mango. These results show that low dose gamma-irradiation in combination with Klin film packaging delayed ripening as indicated by higher retention of fruit colour and reduction of PWL. (author)

  18. Wheel-running activity and energy metabolism in relation to ambient temperature in mice selected for high wheel-running activity

    NARCIS (Netherlands)

    Vaanholt, Lobke M.; Garland, Theodore; Daan, Serge; Visser, G. Henk; Garland Jr., Theodore; Heldmaier, G.

    Interrelationships between ambient temperature, activity, and energy metabolism were explored in mice that had been selectively bred for high spontaneous wheel-running activity and their random-bred controls. Animals were exposed to three different ambient temperatures (10, 20 and 30 degrees C) and

  19. Brain responses to ambient temperature fluctuations in fish: reduction of blood volume and initiation of a whole-body stress response.

    NARCIS (Netherlands)

    Burg, E.H. van den; Peeters, RR; Verhoye, M.; Meek, J.; Flik, G.; Linden, A. van der

    2005-01-01

    Spatial and temporal ambient temperature variations directly influence cellular biochemistry and thus the physiology of ectotherms. However, many aquatic ectothermic species maintain coordinated sensorimotor function during large acute body-temperature changes, which points to a compensatory

  20. A Combined State of Charge Estimation Method for Lithium-Ion Batteries Used in a Wide Ambient Temperature Range

    Directory of Open Access Journals (Sweden)

    Fei Feng

    2014-05-01

    Full Text Available Ambient temperature is a significant factor that influences the characteristics of lithium-ion batteries, which can produce adverse effects on state of charge (SOC estimation. In this paper, an integrated SOC algorithm that combines an advanced ampere-hour counting (Adv Ah method and multistate open-circuit voltage (multi OCV method, denoted as “Adv Ah + multi OCV”, is proposed. Ah counting is a simple and general method for estimating SOC. However, the available capacity and coulombic efficiency in this method are influenced by the operating states of batteries, such as temperature and current, thereby causing SOC estimation errors. To address this problem, an enhanced Ah counting method that can alter the available capacity and coulombic efficiency according to temperature is proposed during the SOC calculation. Moreover, the battery SOCs between different temperatures can be mutually converted in accordance with the capacity loss. To compensate for the accumulating errors in Ah counting caused by the low precision of current sensors and lack of accurate initial SOC, the OCV method is used for calibration and as a complement. Given the variation of available capacities at different temperatures, rated/non-rated OCV–SOCs are established to estimate the initial SOCs in accordance with the Ah counting SOCs. Two dynamic tests, namely, constant- and alternated-temperature tests, are employed to verify the combined method at different temperatures. The results indicate that our method can provide effective and accurate SOC estimation at different ambient temperatures.

  1. Effects of ambient temperature on daily hospital admissions for mental disorders in Shanghai, China: A time-series analysis.

    Science.gov (United States)

    Peng, Zhuoxin; Wang, Qi; Kan, Haidong; Chen, Renjie; Wang, Weibing

    2017-07-15

    Evidence for extreme ambient temperature effects on the risk of mental disorders (MDs) is limited. In this study, we evaluated the short-term effects of daily mean temperature on hospital admissions of MDs in Shanghai, China. We obtained daily hospital admission data for MDs, daily meteorological and ambient pollution data in Shanghai from January 2008 to December 2015. Adjusted for time trend, air pollution, relative humidity and other confounders, a quasi-Poisson generalized additive model (GAM) combined with a distributed lag non-linear model (DLNM) was used to analyze the lag-exposure-response relationship between daily mean temperature and hospital admissions for MDs. Total daily hospital admissions for MDs during the study period were 93,971. With a reference of median temperature (18.3°C), there was a significant positive association between the temperature above threshold (24.6°C) and MD hospital admission visits at a lag of 0-1days. The relative risks of extreme hot temperatures (33.1°C, 99% percentile) over the lag 0-1days compared to median temperature were 1.266 (95% confidence intervals: 1.074-1.493). No effect of cold weather on the hospital admissions for MDs was observed. This study suggests that extreme hot temperature poses significant risks on MD; health counseling and cooling measures should be considered for the susceptible population. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Convergent acclimation of leaf photosynthesis and respiration to prevailing ambient temperatures under current and warmer climates in Eucalyptus tereticornis.

    Science.gov (United States)

    Aspinwall, Michael J; Drake, John E; Campany, Courtney; Vårhammar, Angelica; Ghannoum, Oula; Tissue, David T; Reich, Peter B; Tjoelker, Mark G

    2016-10-01

    Understanding physiological acclimation of photosynthesis and respiration is important in elucidating the metabolic performance of trees in a changing climate. Does physiological acclimation to climate warming mirror acclimation to seasonal temperature changes? We grew Eucalyptus tereticornis trees in the field for 14 months inside 9-m tall whole-tree chambers tracking ambient air temperature (Tair ) or ambient Tair  + 3°C (i.e. 'warmed'). We measured light- and CO2 -saturated net photosynthesis (Amax ) and night-time dark respiration (R) each month at 25°C to quantify acclimation. Tree growth was measured, and leaf nitrogen (N) and total nonstructural carbohydrate (TNC) concentrations were determined to investigate mechanisms of acclimation. Warming reduced Amax and R measured at 25°C compared to ambient-grown trees. Both traits also declined as mean daily Tair increased, and did so in a similar way across temperature treatments. Amax and R (at 25°C) both increased as TNC concentrations increased seasonally; these relationships appeared to arise from source-sink imbalances, suggesting potential substrate regulation of thermal acclimation. We found that photosynthesis and respiration each acclimated equivalently to experimental warming and seasonal temperature change of a similar magnitude, reflecting a common, nearly homeostatic constraint on leaf carbon exchange that will be important in governing tree responses to climate warming. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  3. Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

    Directory of Open Access Journals (Sweden)

    J. A. Olorunmaiye

    2012-12-01

    Full Text Available One of the manifestations of climate change is increase.in ambient air temperature usually referred to as global warming. For sustainable development in a country, there is need to identify impacts of climate change and the necessary adaptation and mitigation strategies to adopt. To simulate the effect of global warming on the power consumption of refrigerators, a (model No. 150 THERMOCOOL refrigerator filled with twenty-five 750cl packaged water bottleswas run in an air-conditioned room, in a room with the air-conditioner switched off and near an oven in a bakery. The electric power consumption of the refrigerator was measured using "Watts up?.net" Watt meter and the ambient temperature was measured using FLUKE temperature/humidity meter. The average hourly energy consumption of the refrigerator operating at mean ambient temperatures of 25.4°C, 30.7oC, 38.8°C were 93.844 Wh, 100.32 Wh and 105.08 Wh respectively. Some possible ways to reduce the increase in power consumption of refrigerators due to global warming include using compressors of higher efficiency and condensers of greater effectiveness.

  4. Cold Start Emissions of Spark-Ignition Engines at Low Ambient Temperatures as an Air Quality Risk

    Directory of Open Access Journals (Sweden)

    Bielaczyc Piotr

    2014-12-01

    Full Text Available SI engines are highly susceptible to excess emissions when started at low ambient temperatures. This phenomenon has multiple air quality and climate forcing implications. Direct injection petrol engines feature a markedly different fuelling strategy, and so their emissions behaviour is somewhat different from indirect injection petrol engines. The excess emissions of direct injection engines at low ambient temperatures should also differ. Additionally, the direct injection fuel delivery process leads to the formation of PM, and DISI engines should show greater PM emissions at low ambient temperatures. This study reports on laboratory experiments quantifying excess emissions of gaseous and solid pollutants over a legislative driving cycle following cold start at a low ambient temperature for both engine types. Over the legislative cycle for testing at -7°C (the UDC, emissions of HC, CO, NOx and CO2 were higher when tested at -7°C than at 24°C. Massive increases in emissions of HC and CO were observed, together with more modest increases in NOx and CO2 emissions. Results from the entire driving cycle showed excess emissions in both phases (though they were much larger for the UDC. The DISI vehicle showed lower increases in fuel consumption than the port injected vehicles, but greater increases in emission of HC and CO. DISI particle number emissions increased by around 50%; DISI particle mass by over 600%. The observed emissions deteriorations varied somewhat by engine type and from vehicle to vehicle. Excesses were greatest following start-up, but persisted, even after several hundred seconds’ driving. The temperature of the intake air appeared to have a limited but significant effect on emissions after the engine has been running for some time. All vehicles tested here comfortably met the relevant EU limits, providing further evidence that these limits are no longer challenging and need updating.

  5. High ambient temperature reverses hypothalamic MC4 receptor overexpression in an animal model of anorexia nervosa.

    Science.gov (United States)

    Gutiérrez, E; Churruca, I; Zárate, J; Carrera, O; Portillo, M P; Cerrato, M; Vázquez, R; Echevarría, E

    2009-04-01

    The potential involvement of the melanocortin system in the beneficial effects of heat application in rats submitted to activity-based anorexia (ABA), an analogous model of anorexia nervosa (AN), was studied. Once ABA rats had lost 20% of body weight, half of the animals were exposed to a high ambient temperature (HAT) of 32 degrees C, whereas the rest were maintained at 21 degrees C. Control sedentary rats yoked to ABA animals received the same treatment. ABA rats (21 degrees C) showed increased Melanocortin 4 (MC4) receptor and Agouti gene Related Peptide (AgRP) expression, and decreased pro-opiomelanocortin (POMC) mRNA levels (Real Time PCR), with respect to controls. Heat application increased weight gain and food intake, and reduced running rate in ABA rats, when compared with ABA rats at 21 degrees C. However, no changes in body weight and food intake were observed in sedentary rats exposed to heat. Moreover, heat application reduced MC4 receptor, AgRP and POMC expression in ABA rats, but no changes were observed in control rats. These results indicate that hypothalamic MC4 receptor overexpression could occur on the basis of the characteristic hyperactivity, weight loss, and self-starvation of ABA rats, and suggest the involvement of hypothalamic melanocortin neural circuits in behavioural changes shown by AN patients. Changes in AgRP and POMC expression could represent an adaptative response to equilibrate energy balance. Moreover, the fact that HAT reversed hypothalamic MC4 receptor overexpression in ABA rats indicates the involvement of brain melanocortin system in the reported beneficial effects of heat application in AN. A combination of MC4 receptor antagonists and heat application could improve the clinical management of AN.

  6. Reactor Design for CO2 Photo-Hydrogenation toward Solar Fuels under Ambient Temperature and Pressure

    Directory of Open Access Journals (Sweden)

    Chun-Ying Chen

    2017-02-01

    Full Text Available Photo-hydrogenation of carbon dioxide (CO2 is a green and promising technology and has received much attention recently. This technique could convert solar energy under ambient temperature and pressure into desirable and sustainable solar fuels, such as methanol (CH3OH, methane (CH4, and formic acid (HCOOH. It is worthwhile to mention that this direction can not only potentially depress atmospheric CO2, but also weaken dependence on fossil fuel. Herein, 1 wt % Pt/CuAlGaO4 photocatalyst was successfully synthesized and fully characterized by ultraviolet-visible light (UV-vis spectroscopy, X-ray diffraction (XRD, Field emission scanning electron microscopy using energy dispersive spectroscopy analysis (FE-SEM/EDS, transmission electron microscopy (TEM, X-ray photoelectron spectroscopy (XPS, and Brunauer-Emmett-Teller (BET, respectively. Three kinds of experimental photo-hydrogenation of CO2 in the gas phase, liquid phase, and gas-liquid phase, correspondingly, were conducted under different H2 partial pressures. The remarkable result has been observed in the gas-liquid phase. Additionally, increasing the partial pressure of H2 would enhance the yield of product. However, when an extra amount of H2 is supplied, it might compete with CO2 for occupying the active sites, resulting in a negative effect on CO2 photo-hydrogenation. For liquid and gas-liquid phases, CH3OH is the major product. Maximum total hydrocarbons 8.302 µmol·g−1 is achieved in the gas-liquid phase.

  7. 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. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Energy from Biomass - Comparision of biogas production at ambient temperature and at mesophilic temperature in semicontenous anaerobic digester using vegetable market waste

    Directory of Open Access Journals (Sweden)

    Dhanalakshmi Sridevi V.

    2014-03-01

    Full Text Available Studies are conducted in semicontinuous anaerobic reactors of 2 L Capacity with effective volume of 1.5 L. Experiments were carried out in the mesophilic temperature range maintained at 35°C in a thermostat, and parallel experiments were performed at ambient temperature on biogas production from the month of Februray to August. The reactors were operated with an organic loading rate of 0.5 gVS/L/d with 25 days HRT. The feed stock used for the study was vegetable market waste obtained from Koyambedu vegetable market. The specific biogas production was found to be 0.530 L gVS add-1 for the reactor operated at mesophilic temperature and in the range of 0.431 to 0.732 L gVSadd -1 for the reactor operated in the ambient temperature condition from the month of February to August. The daily biogas production was found to be similar (approximately 350 mL/d when reactors were operated at mesophilic and ambient temperature except for the period of May and June wherein higher amount of daily biogas production (472 and 529 mL/d was observed in the reactor operated at ambient temperature. The ratio of total VFA and alkalinity and propionic acid to acetic acid (PA/AA was found to be in the range of 0.25 – 0.4 and 0.34 - 1.38 during the operation of the reactor for the entire period, which was within the range reported for digester stability.

  9. Ambient Air Temperature Does Not Predict whether Small or Large Workers Forage in Bumble Bees (Bombus impatiens

    Directory of Open Access Journals (Sweden)

    Margaret J. Couvillon

    2010-01-01

    Full Text Available Bumble bees are important pollinators of crops and other plants. However, many aspects of their basic biology remain relatively unexplored. For example, one important and unusual natural history feature in bumble bees is the massive size variation seen between workers of the same nest. This size polymorphism may be an adaptation for division of labor, colony economics, or be nonadaptive. It was also suggested that perhaps this variation allows for niche specialization in workers foraging at different temperatures: larger bees might be better suited to forage at cooler temperatures and smaller bees might be better suited to forage at warmer temperatures. This we tested here using a large, enclosed growth chamber, where we were able to regulate the ambient temperature. We found no significant effect of ambient or nest temperature on the average size of bees flying to and foraging from a suspended feeder. Instead, bees of all sizes successfully flew and foraged between 16∘C and 36∘C. Thus, large bees foraged even at very hot temperatures, which we thought might cause overheating. Size variation therefore could not be explained in terms of niche specialization for foragers at different temperatures.

  10. Structural Studies of NH4-exchanged Natrolites at Ambient Conditions and High Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Y Lee; D Seoung; Y Jang; J Bai; Y Lee

    2011-12-31

    We report here for the first time that fully and partially NH{sub 4}-exchanged natrolites can be prepared in hydrated states using the solution exchange method with potassium-natrolite. The structural models of the as-prepared hydrated phases and their dehydrated forms at elevated temperature were refined in space group Fdd2 using in situ synchrotron X-ray powder diffraction data and Rietveld methods. The unit-cell volumes of the hydrated NH{sub 4}-exchanged natrolites at ambient conditions, (NH{sub 4}){sub 16(2)}Al{sub 16}Si{sub 24}O{sub 80}{center_dot}14.1(9)H{sub 2}O and (NH{sub 4}){sub 5.1(1)}K{sub 10.9(1)}Al{sub 16}Si{sub 24}O{sub 80}{center_dot}15.7(3)H{sub 2}O, are found to be larger than that the original sodium-natrolite by ca. 15.6% and 12.8%, respectively. Upon temperature increase, the fully NH{sub 4}-exchanged natrolite undergoes dehydration at ca. 150 C with ca. 16.4% contraction in the unit-cell volume. The dehydrated phase of the fully NH{sub 4}-exchanged natrolite exhibits marginal volume expansion up to 425 C and then becomes amorphized during temperature decrease and exposure to atmospheric condition. In the case of the partially NH{sub 4}-exchanged natrolite, the dehydration starts from ca. 175 C with {approx}15.1% volume contraction and leads to a partial phase separation to show a phase related to the dehydrated K-natrolite. The degree of the phase separation decreases with temperature increase up to 475 C, concomitant to the gradual volume contraction occurring in the partially NH{sub 4}-exchanged natrolite in the dehydrared state. Upon temperature decrease and exposure to atmospheric condition, only the dehydrated K-natrolite is recovered as a crystalline phase from the partially NH{sub 4}-exchanged natrolite. In the hydrated model of the fully NH{sub 4}-exchanged natrolite, the ammonium cations and water molecules are statistically distributed along the elliptical channels, similar to the disordered pattern observed in natrolites exchanged

  11. Dietary l-arginine supplementation improves semen quality and libido of boars under high ambient temperature.

    Science.gov (United States)

    Chen, J Q; Li, Y S; Li, Z J; Lu, H X; Zhu, P Q; Li, C M

    2017-12-04

    l-Arginine is a nutritionally essential amino acid for spermatogenesis and plays versatile roles in animal health and can be utilized as a potential agent to improve reproductive performance of boars under high ambient temperature. The present study aimed to determine whether dietary l-arginine could alleviate heat stress-induced infertility in boars. In all, 20 boars (PIC 1040; 248.59±3.84 kg BW and 407.65±6.40 days of age) were selected and randomly assigned to four groups (group 0.0%, basal diet; group 0.6%, 0.8% or 1.0%, basal diet added with 0.6%, 0.8% or 1.0% l-arginine (wt:wt), respectively.) The four diets were made isonitrogenous by addition of appropriate amounts of l-alanine. Boars were pre-fed the corresponding experimental diet for 42 days. Then, the semen characteristics and libido were accessed for 6 weeks during the hot summer period (25.5° to 33.0°C). Results show that dietary l-arginine remarkably improved sperm motility, normality, total sperm number and effective total sperm number. Also, dietary l-arginine improved semen antioxidant capacity, such as decrease of malondialdehyde and 8-Hydroxy-2'-deoxyguanosine content in sperm (Pl-arginine-supplemented group which also accompany with higher ATP content than the 0.0% group. The boars fed 0.8% l-arginine show increased levels of estradiol-17β and testosterone and exhibit improved libido performance than boars in the 0.0% group. Adding dietary l-arginine linearly increased (P=0.002) nitric oxide content (as l-arginine increased). The scrotal surface temperature in the 0.6%, 0.8% and 1.0% group were decreased by 0.9°C, 0.9°C and 0.4°C, respectively, compared with the 0.0% group. l-Arginine levels caused linear effect on semen quality and antioxidant capacity, also caused quadratic effect on libido performance. During the hot summer months, the predicted optimal l-arginine levels for best semen quality and antioxidant capacity was 0.8% to 1.0% and for best libido performance was 0.8%. It can

  12. Silver nanowires network encapsulated by low temperature sol-gel ZnO for transparent flexible electrodes with ambient stability

    Science.gov (United States)

    Shin, Wonjung; Cho, Wonki; Baik, Seung Jae

    2018-01-01

    As a geometrically engineered realization of transparent electrode, Ag nanowires network is promising for its superior characteristics both on electrical conductivity and optical transmittance. However, for a potential commercialization of Ag nanowires network, further investigations on encapsulation materials are necessary to prevent degradation caused by ambient aging. In addition, the temperature range of the coating process for the encapsulation material needs to be low enough to prevent degradation of polymer substrates during the film coating processes, when considering emerging flexible device application of transparent electrodes. We present experimental results showing that low temperature sol-gel ZnO processed under 130 °C is an effective encapsulation material preventing ambient oxidation of Ag nanowires network without degrading electrical, optical, and mechanical properties.

  13. Ambient Levels of Primary and Secondary Pollutants in a Residential Area: Population Risk and Hazard Index Calculation over a Three Years Study Period

    OpenAIRE

    S. Al-Salem; A. Al-Fadhlee

    2007-01-01

    This paper aims at presenting data collected over the period of three years (2004-2006) in a residential area in the state of Kuwait. The data collected include ambient levels of primary and secondary pollutants with a number of metrological parameters. A series of unfiltered and filtered concentration roses were plotted to determine the predominant sources as well as the prevailing winds affecting the area under investigation. Local and international air quality regulations were cross refere...

  14. The temperature control and water quality regulation for steam generator secondary side hydrostatic test

    International Nuclear Information System (INIS)

    Xiao Bo; Liu Dongyong

    2014-01-01

    The secondary side hydrostatic test for the steam generator of M310 unit is to verify the pressure tightness of steam generator secondary side tube sheet and related systems. As for the importance of the steam generator, the water temperature and water quality of hydrostatic test has strict requirements. The discussion on the water temperature control and water quality regulation for the secondary loop hydrostatic test of Fuqing Unit 1 contribute greatly to the guiding work for the preparation of the steam generator pressure test for M310 unit. (authors)

  15. Effects of ambient temperature on sleep and cardiovascular regulation in mice: the role of hypocretin/orexin neurons.

    Directory of Open Access Journals (Sweden)

    Viviana Lo Martire

    Full Text Available The central neural pathways underlying the physiological coordination between thermoregulation and the controls of the wake-sleep behavior and cardiovascular function remain insufficiently understood. Growing evidence supports the involvement of hypocretin (orexin peptides in behavioral, cardiovascular, and thermoregulatory functions. We investigated whether the effects of ambient temperature on wake-sleep behavior and cardiovascular control depend on the hypothalamic neurons that release hypocretin peptides. Orexin-ataxin3 transgenic mice with genetic ablation of hypocretin neurons (n = 11 and wild-type controls (n = 12 were instrumented with electrodes for sleep scoring and a telemetric blood pressure transducer. Simultaneous sleep and blood pressure recordings were performed on freely-behaving mice at ambient temperatures ranging between mild cold (20°C and the thermoneutral zone (30°C. In both mouse groups, the time spent awake and blood pressure were higher at 20°C than at 30°C. The cold-related increase in blood pressure was significantly smaller in rapid-eye-movement sleep (REMS than either in non-rapid-eye-movement sleep (NREMS or wakefulness. Blood pressure was higher in wakefulness than either in NREMS or REMS at both ambient temperatures. This effect was significantly blunted in orexin-ataxin3 mice irrespective of ambient temperature and particularly during REMS. These data demonstrate that hypocretin neurons are not a necessary part of the central pathways that coordinate thermoregulation with wake-sleep behavior and cardiovascular control. Data also support the hypothesis that hypocretin neurons modulate changes in blood pressure between wakefulness and the sleep states. These concepts may have clinical implications in patients with narcolepsy with cataplexy, who lack hypocretin neurons.

  16. Effects of ambient temperature on sleep and cardiovascular regulation in mice: the role of hypocretin/orexin neurons.

    Science.gov (United States)

    Lo Martire, Viviana; Silvani, Alessandro; Bastianini, Stefano; Berteotti, Chiara; Zoccoli, Giovanna

    2012-01-01

    The central neural pathways underlying the physiological coordination between thermoregulation and the controls of the wake-sleep behavior and cardiovascular function remain insufficiently understood. Growing evidence supports the involvement of hypocretin (orexin) peptides in behavioral, cardiovascular, and thermoregulatory functions. We investigated whether the effects of ambient temperature on wake-sleep behavior and cardiovascular control depend on the hypothalamic neurons that release hypocretin peptides. Orexin-ataxin3 transgenic mice with genetic ablation of hypocretin neurons (n = 11) and wild-type controls (n = 12) were instrumented with electrodes for sleep scoring and a telemetric blood pressure transducer. Simultaneous sleep and blood pressure recordings were performed on freely-behaving mice at ambient temperatures ranging between mild cold (20°C) and the thermoneutral zone (30°C). In both mouse groups, the time spent awake and blood pressure were higher at 20°C than at 30°C. The cold-related increase in blood pressure was significantly smaller in rapid-eye-movement sleep (REMS) than either in non-rapid-eye-movement sleep (NREMS) or wakefulness. Blood pressure was higher in wakefulness than either in NREMS or REMS at both ambient temperatures. This effect was significantly blunted in orexin-ataxin3 mice irrespective of ambient temperature and particularly during REMS. These data demonstrate that hypocretin neurons are not a necessary part of the central pathways that coordinate thermoregulation with wake-sleep behavior and cardiovascular control. Data also support the hypothesis that hypocretin neurons modulate changes in blood pressure between wakefulness and the sleep states. These concepts may have clinical implications in patients with narcolepsy with cataplexy, who lack hypocretin neurons.

  17. Experimental Investigation of the Effect of Change in Ambient Air Temperature on Power Consumption of Domestic Refrigerators

    OpenAIRE

    J. A. Olorunmaiye; O. O. Awolola; J. F. Oladiji

    2012-01-01

    One of the manifestations of climate change is increase.in ambient air temperature usually referred to as global warming. For sustainable development in a country, there is need to identify impacts of climate change and the necessary adaptation and mitigation strategies to adopt. To simulate the effect of global warming on the power consumption of refrigerators, a (model No. 150) THERMOCOOL refrigerator filled with twenty-five 750cl packaged water bottleswas run in an air-conditioned room, in...

  18. Measurements of Potential Secondary Organic Aerosol Formation from OH, O3, and NO3 oxidation of Ambient Air: a Contrast of Different Anthropogenically-Influenced Biogenic Environments

    Science.gov (United States)

    Jimenez, J. L.

    2016-12-01

    Oxidation flow reactors (OFRs) are useful tools for studying potential secondary organic aerosol (SOA) formation from OH, O3, or NO3 oxidation in both laboratory and field experiments. With a several-minute residence time and a portable design with no inlet, OFRs are particularly well-suited for oxidizing ambient air to investigate in situ SOA formation from real ambient precursors. In recent years, our team has pioneered the use of OFRs to quantify SOA potential from a wide variety of environments, including a rural pine forest in the Rocky Mountains, a regionally polluted deciduous/coniferous forest in the SE US, the Amazon rain forest, air influenced by biomass burning, and urban outflow. We present a comparison of the SOA production from these contrasting sources. In all settings, the amount of SOA formed was larger at night than during the day. In forests, the amount of potential SOA after oxidation of ambient air correlated with biogenic precursors (e.g., monoterpenes). In urban air, potential SOA formation correlated instead with reactive anthropogenic tracers (e.g., trimethylbenzene). Despite these correlations, the SOA predicted to be formed by the oxidation of speciated ambient VOC concentrations could only explain approximately 10-50% of the total SOA formed from the oxidation of ambient air, regardless of location. Evidence suggests that lower-volatility gases (semivolatile and intermediate-volatility organic compounds; S/IVOCs) are present in ambient air and are a likely source of the SOA formation that cannot be explained by VOCs. These measurements show that S/IVOCs likely play an important intermediary role in ambient SOA formation in all of the sampled locations, from rural forests to urban air. Characteristics of the SOA formed from different air masses, e.g., H:C and O:C ratios of newly formed SOA as well as PMF factor analysis, will also be discussed.

  19. Effect of ambient temperature on nutrient digestibility and nitrogen balance in sheep fed brown-midrib maize silage.

    Science.gov (United States)

    Gorniak, Tobias; Meyer, Ulrich; Südekum, Karl-Heinz; Dänicke, Sven

    2014-01-01

    The aim of the experiment was to determine the impact of heat stress on nutrient digestibility and nitrogen balance in sheep fed silages differing in fibre quality. The digestibility trial was conducted at three different ambient temperatures (15°C, 25°C and 35°C for 24 h/d). The tested brown-midrib maize (Bm) silage had a higher nutrient digestibility, except for ether extract (EE) and a higher metabolisable energy (ME) content than the control maize (Con) silage. Nitrogen (N) excretion with faeces was higher but N excretion with urine was lower for sheep fed Bm silage, subsequently N balance did not differ between the two silages. Temperature had no effect on nutrient digestibility, except for crude protein (CP), but N excretion with urine was lower at elevated temperatures. A diet by temperature interaction was found for dry matter (DM) and organic matter (OM) digestibility. When the ambient temperature increased from 15°C to 25°C, the DM and OM digestibility increased in animals fed Con silage, but decreased in animals fed Bm silage. Concomitantly, ME estimated from digestible nutrients was higher for Bm than for Con at 15°C, but no differences were found at 25°C and 35°C. Effects of diet by temperature interaction, furthermore, were observed for EE and CP digestibility. Therefore, forage quality has to be considered when feeding heat-stressed animals.

  20. Effects of Ambient Temperature on Growth Performance, Blood Metabolites, and Immune Cell Populations in Korean Cattle Steers

    Directory of Open Access Journals (Sweden)

    H. J. Kang

    2016-03-01

    Full Text Available Exposure to cold may affect growth performance in accordance with the metabolic and immunological activities of animals. We evaluated whether ambient temperature affects growth performance, blood metabolites, and immune cell populations in Korean cattle. Eighteen Korean cattle steers with a mean age of 10 months and a mean weight of 277 kg were used. All steers were fed a growing stage-concentrate diet at a rate of 1.5% of body weight and Timothy hay ad libitum for 8 weeks. Experimental period 1 (P1 was for four weeks from March 7 to April 3 and period 2 (P2 was four weeks from April 4 to May 1. Mean (8.7°C and minimum (1.0°C indoor ambient temperatures during P1 were lower (p<0.001 than those (13.0°C and 6.2°C, respectively during P2. Daily dry matter feed intake in both the concentrate diet and forage groups was higher (p<0.001 during P2 than P1. Average daily weight gain was higher (p<0.001 during P2 (1.38 kg/d than P1 (1.13 kg/d. Feed efficiency during P2 was higher (p = 0.015 than P1. Blood was collected three times; on March 7, April 4, and May 2. Nonesterified fatty acids (NEFA were higher on March 7 than April 4 and May 2. Blood cortisol, glucose, and triglyceride concentrations did not differ among months. Blood CD4+, CD8+, and CD4+CD25+ T cell percentages were higher, while CD8+CD25+ T cell percentage was lower, during the colder month of March than during May, suggesting that ambient temperature affects blood T cell populations. In conclusion, colder ambient temperature decreased growth and feed efficiency in Korean cattle steers. The higher circulating NEFA concentrations observed in March compared to April suggest that lipolysis may occur at colder ambient temperatures to generate heat and maintain body temperature, resulting in lower feed efficiency in March.

  1. Impact of Ambient Temperatures on Exhaust Thermal Characteristics during Cold Start for Real World SI Car Urban Driving Tests

    OpenAIRE

    Li, H; Andrews, GE; Zhu, G; Daham, BK; Bell, MC; Tate, JE; Ropkins, K

    2005-01-01

    Thermal characteristics of SI engine exhaust during cold start and warm up period were investigated for different ambient temperatures (-2 to 32 °C). A Euro 1 emission compliance SI car was tested using a real world urban driving cycle to represent typical city driving patterns and simulate ECE15 urban driving cycle. The test car was equipped with 27 thermocouples along the engine and exhaust pipes so as to measure metal and exhaust gas temperatures along the engine, exhaust and catalyst. The...

  2. Electrochemistry of Centered Hexanuclear Zirconium Halide Clusters in Ambient-Temperature Chloroaluminate Molten Salts.

    Science.gov (United States)

    Sun, Dong; Hughbanks, Timothy

    1999-03-08

    Ambient temperature AlCl(3)-1-ethyl-3-methylimidazolium chloride (ImCl) molten salts, both basic (40/60 mol % AlCl(3)/ImCl) and acidic (60/40 mol % AlCl(3)/ImCl), were used in an electrochemical investigation of centered hexanuclear zirconium halide clusters. In the basic molten salt, these [(Zr(6)ZCl(12))Cl(6)](n-) (Z = Be, B, C, Mn, Fe) centered clusters exhibit the following electrochemical reactions on a glassy carbon electrode (potentials vs Al/Al(3+)): [(Zr(6)BeCl(12))Cl(6)](n)()(-) + e(-) right harpoon over left harpoon [(Zr(6)BeCl(12))Cl(6)](()(n)()(+1))(-), E(1/2) = -0.613 V (n = 4), E(1/2) = -1.085 V (n = 5); [(Zr(6)BCl(12))Cl(6)](n)()(-) + e(-) right harpoon over left harpoon [(Zr(6)BCl(12))Cl(6)](()(n)()(+1))(-), E(1/2) = -0.365 V (n = 4), E(1/2) = 0.072 V (n = 3); [(Zr(6)CCl(12))Cl(6)](n)()(-) + e(-) right harpoon over left harpoon [(Zr(6)CCl(12))Cl(6)](()(n)()(+1))(-), E(1/2) = 0.230 V (n = 3); [(Zr(6)MnCl(12))Cl(6)](4)(-) + e(-) right harpoon over left harpoon [(Zr(6)MnCl(12))Cl(6)](5)(-), E(1/2) = -0.432 V. In the acidic melt, only electrochemical reactions [(Zr(6)BeCl(12))(AlCl(4))(6)](n)()(-) + e(-) right harpoon over left harpoon [(Zr(6)BeCl(12))(AlCl(4))(6)](()(n)()(+1))(-), E(1/2) = -0.069 V (n = 5), E(1/2) = 0.504 V (n = 4), and [(Zr(6)BCl(12))(AlCl(4))(6)](4)(-) + e(-) right harpoon over left harpoon [(Zr(6)BCl(12))(AlCl(4))(6)](5)(-), E(1/2) = 0.700 V are clearly observed. These data is consistent with less systematic observations of oxidation of these clusters in solution. No unambiguous one-electron electrochemical reduction nor oxidation is observable for the Fe-centered cluster in the ionic liquids. The half-wave potentials of the above reactions of the Be-, B-, C-, and Mn-centered clusters are controlled largely by clusters' charges. This correlation of redox potentials allows a useful direct comparison with data for related hexanuclear niobium clusters in the literature.

  3. Experimental investigation on heating performance of heat pump for electric vehicles at −20 °C ambient temperature

    International Nuclear Information System (INIS)

    Qin, Fei; Xue, Qingfeng; Albarracin Velez, Giovanny Marcelo; Zhang, Guiying; Zou, Huiming; Tian, Changqing

    2015-01-01

    Highlights: • An ASHP system with refrigerant injection for EVs is designed, for cold regions. • The heat performances of the system are tested at −20 °C ambient temperature. • The system cycle process with refrigerant injection are analyzed on lgP-H diagrams. • The effects of refrigerant injection, dryness, and in-car inlet state are discussed. • The new system can improve heating and own better application prospect. - Abstract: Since the performance of conventional air source heat pump (ASHP) for electric vehicles (EVs) is apt to decline sharply in low ambient temperature, it will consume more electricity of the cell, and affect driving mileage in cold regions. Aiming at developing high efficiency heating system for EVs in cold regions, an ASHP system applying refrigerant injection for EVs is designed, as well as the test bench is built to investigate its performance. According to the operation condition of EVs, heating performances are tested on different in-car inlet air temperature and various fresh air ratios under −20 °C ambient temperature. The system cycle process with refrigerant injection, as well as the influences of refrigerant injection and dryness are also analyzed and discussed. The results show that the heating capacity of the ASHP with refrigerant injection can be increased up to 31%, and in comparison with the conventional heat pump system its heating performance is better when in-car inlet temperature is above −10 °C. Therefore, ASHP with refrigerant injection has great potentiality to be applied for the EVs in cold regions

  4. Elongated Hypocotyl 5-Homolog (HYH Negatively Regulates Expression of the Ambient Temperature-Responsive MicroRNA Gene MIR169

    Directory of Open Access Journals (Sweden)

    Phanu T. Serivichyaswat

    2017-12-01

    Full Text Available Arabidopsis microRNA169 (miR169 is an ambient temperature-responsive microRNA that plays an important role in stress responses and the floral transition. However, the transcription factors that regulate the expression of MIR169 have remained unknown. In this study, we show that Elongated Hypocotyl 5-Homolog (HYH directly binds to the promoter of MIR169a and negatively regulates its expression. Absolute quantification identified MIR169a as the major locus producing miR169. GUS reporter assays revealed that the deletion of a 498-bp fragment (–1,505 to –1,007, relative to the major transcriptional start site of MIR169a abolished its ambient temperature-responsive expression. DNA-affinity chromatography followed by liquid chromatography-mass spectrometry analysis identified transcription factor HYH as a trans-acting factor that binds to the 498-bp promoter fragment of pri-miR169a. Electrophoretic mobility shift assays and chromatin immunoprecipitation–quantitative PCR demonstrated that the HYH.2 protein, a predominant isoform of HYH, directly associated with a G-box-like motif in the 498-bp fragment of pri-miR169a. Higher enrichment of HYH.2 protein on the promoter region of MIR169a was seen at 23°C, consistent with the presence of more HYH.2 protein in the cell at the temperature. Transcript levels of pri-miR169a increased in hyh mutants and decreased in transgenic plants overexpressing HYH. Consistent with the negative regulation of MIR169a by HYH, the diurnal levels of HYH mRNA and pri-miR169a showed opposite patterns. Taken together, our results suggest that HYH is a transcription factor that binds to a G-box-like motif in the MIR169a promoter and negatively regulates ambient temperature-responsive expression of MIR169a at higher temperatures in Arabidopsis.

  5. Effect of Different Arbuscular Mycorrhizal Fungi on Growth and Physiology of Maize at Ambient and Low Temperature Regimes

    Directory of Open Access Journals (Sweden)

    Xiaoying Chen

    2014-01-01

    Full Text Available The effect of four different arbuscular mycorrhizal fungi (AMF on the growth and lipid peroxidation, soluble sugar, proline contents, and antioxidant enzymes activities of Zea mays L. was studied in pot culture subjected to two temperature regimes. Maize plants were grown in pots filled with a mixture of sandy and black soil for 5 weeks, and then half of the plants were exposed to low temperature for 1 week while the rest of the plants were grown under ambient temperature and severed as control. Different AMF resulted in different root colonization and low temperature significantly decreased AM colonization. Low temperature remarkably decreased plant height and total dry weight but increased root dry weight and root-shoot ratio. The AM plants had higher proline content compared with the non-AM plants. The maize plants inoculated with Glomus etunicatum and G. intraradices had higher malondialdehyde and soluble sugar contents under low temperature condition. The activities of catalase (CAT and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology and AM symbiosis can improve maize seedlings tolerance to low temperature stress.

  6. The potential effect of differential ambient and deployment chamber temperatures on PRC derived sampling rates with polyurethane foam (PUF) passive air samplers

    International Nuclear Information System (INIS)

    Kennedy, Karen; Hawker, Darryl W.; Bartkow, Michael E.; Carter, Steve; Ishikawa, Yukari; Mueller, Jochen F.

    2010-01-01

    Performance reference compound (PRC) derived sampling rates were determined for polyurethane foam (PUF) passive air samplers in both sub-tropical and temperate locations across Australia. These estimates were on average a factor of 2.7 times higher in summer than winter. The known effects of wind speed and temperature on mass transfer coefficients could not account for this observation. Sampling rates are often derived using ambient temperatures, not the actual temperatures within deployment chambers. If deployment chamber temperatures are in fact higher than ambient temperatures, estimated sampler-air partition coefficients would be greater than actual partition coefficients resulting in an overestimation of PRC derived sampling rates. Sampling rates determined under measured ambient temperatures and estimated deployment chamber temperatures in summer ranged from 7.1 to 10 m 3 day -1 and 2.2-6.8 m 3 day -1 respectively. These results suggest that potential differences between ambient and deployment chamber temperatures should be considered when deriving PRC-based sampling rates. - Internal deployment chamber temperatures rather than ambient temperatures may be required to accurately estimate PRC-based sampling rates.

  7. Effects of stimulus mode and ambient temperature on cerebral responses to local thermal stimulation: An EEG study.

    Science.gov (United States)

    Lv, Bin; Su, Chang; Yang, Lei; Wu, Tongning

    2017-03-01

    The physiological responses to human thermal stimulation have been widely investigated, but most of them are mainly concerned about the whole body thermal stimulation. In this study, we investigated the effects of stimulus mode and ambient temperature on cerebral responses during local thermal stimulation on hand. The left hands were stimulated by metal thermostat based and thermostatic water based stimulators at different stimulated temperatures (38°C, 40°C, 42°C and 44°C) and different ambient temperatures (25°C and 32°C). EEG data were recorded over the whole brain during the experiments. Then the statistical comparisons were conducted on the EEG relative power among different experimental sessions. We observed that EEG activities were alternated between thermal stimulated periods and the baseline in all four frequency bands. And there was a higher percentage of delta band power in the right temporal and parietal regions under the ambient temperature of 32°C while compared to 25°C. In addition, the theta band activity under the metal based stimulation showed significantly higher EEG relative power than that under the water based stimulation over the whole brain. Compared with the water based stimulation, there was a lower EEG relative power of the beta band activity during the metal based stimulation in the bilateral frontal and right temporal regions. The experimental results suggested that the neural physiological responses in different EEG frequency bands were sensitive to different influence factors during the local hand thermal stimulation. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Alternative Refrigerant Evaluation for High-Ambient Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [ORNL; Munk, Jeffrey D [ORNL; Shrestha, Som S [ORNL; Linkous, Randall Lee [ORNL; Goetzler, William [Navigant Consulting Inc.; Guernsey, Matt [Navigant Consulting Inc.; Kassuga, Theo [Navigant Consulting Inc.

    2015-08-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient Temperature Testing Program for Low-GWP Refrigerants aims to develop an understanding of the performance of low-Global Warming Potential (low-GWP) alternatives to Hydrochlorofluorocarbon (HCFC) and Hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high ambient temperature conditions. This interim working paper describes the parties involved, the alternative refrigerants selection process, the test procedures, and the preliminary results.

  9. Alternative Refrigerant Evaluation for High-Ambient-Temperature Environments: R-22 and R-410A Alternatives for Mini-Split Air Conditioners

    Energy Technology Data Exchange (ETDEWEB)

    Abdelaziz, Omar [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Shrestha, Som S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Munk, Jeffrey D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Linkous, Randall Lee [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Goetzler, William [Navigant Consulting Inc., Burlington, MA (United States); Guernsey, Matt [Navigant Consulting Inc., Burlington, MA (United States); Kassuga, Theo [Navigant Consulting Inc., Burlington, MA (United States)

    2015-10-01

    The Oak Ridge National Laboratory (ORNL) High-Ambient-Temperature Evaluation Program for low– global warming potential (Low-GWP) Refrigerants aims to develop an understanding of the performance of low-GWP alternative refrigerants to hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants in mini-split air conditioners under high-ambient-temperature conditions. This final report describes the parties involved, the alternative refrigerant selection process, the test procedures, and the final results.

  10. Analysis of high injection pressure and ambient temperature on biodiesel spray characteristics using computational fluid dynamics

    Science.gov (United States)

    Hashim, Akasha; Khalid, Amir; Jaat, Norrizam; Sapit, Azwan; Razali, Azahari; Nizam, Akmal

    2017-09-01

    Efficiency of combustion engines are highly affected by the formation of air-fuel mixture prior to ignition and combustion process. This research investigate the mixture formation and spray characteristics of biodiesel blends under variant in high ambient and injection conditions using Computational Fluid Dynamics (CFD). The spray characteristics such as spray penetration length, spray angle and fluid flow were observe under various operating conditions. Results show that increase in injection pressure increases the spray penetration length for both biodiesel and diesel. Results also indicate that higher spray angle of biodiesel can be seen as the injection pressure increases. This study concludes that spray characteristics of biodiesel blend is greatly affected by the injection and ambient conditions.

  11. Air Ambient-Operated pNIPAM-Based Flexible Actuators Stimulated by Human Body Temperature and Sunlight.

    Science.gov (United States)

    Yamamoto, Yuki; Kanao, Kenichiro; Arie, Takayuki; Akita, Seiji; Takei, Kuniharu

    2015-05-27

    Harnessing a natural power source such as the human body temperature or sunlight should realize ultimate low-power devices. In particular, macroscale and flexible actuators that do not require an artificial power source have tremendous potential. Here we propose and demonstrate electrically powerless polymer-based actuators operated at ambient conditions using a packaging technique in which the stimulating power source is produced by heat from the human body or sunlight. The actuating angle, force, and reliability are discussed as functions of temperature and exposure to sunlight. Furthermore, a wearable device platform and a smart curtain actuated by the temperature of human skin and sunlight, respectively, are demonstrated as the first proof-of-concepts. These nature-powered actuators should realize a new class of ultimate low-power devices.

  12. Supplementation with turmeric residue increased survival of the Chinese soft-shelled turtle (Pelodiscus sinensis) under high ambient temperatures.

    Science.gov (United States)

    Chen, Yong; Zhang, Yi-Fan; Qian, Hao-Cheng; Wang, Jing-Liang; Chen, Zhe; Ordovas, Jose M; Lai, Chao-Qiang; Shen, Li-Rong

    Turmeric residue (TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the effects of TR on the survival of Chinese soft-shelled turtles (SSTs), Pelodiscus sinensis, under a high ambient temperature. A total of 320 female SSTs were assigned randomly to two diets: basal diet (the control group, n=160) and an interventional diet supplemented with 10% TR (the TR group, n=160). Our results demonstrated that supplementation of TR increased the SST survival rate by 135.5%, and superoxide dismutase (SOD) activity of SST liver by 112.8%, and decreased the malondialdehyde (MDA) content of SST liver by 36.4%, compared to the control group. The skin of the SST fed TR showed a golden color. High-performance liquid chromatography (HPLC) analysis indicated that the concentrations of curcumin in TR and the skin of the SST fed TR were (1.69±0.30) and (0.14±0.03) μg/g, respectively. Our observation suggests that supplementation of TR increased the survival rate of SST under high ambient temperatures. We speculated that the increased survival rate and tolerance at the high ambient temperature were associated with the anti-oxidation activity of curcumin from TR. Moreover, curcumin in TR could be deposited in SST skin, which made it more favored in the market of China. Our findings provide new knowledge and evidence to effectively reuse TR as a feed additive in animal and aquatic farming.

  13. Short communication: Comparison of ambient temperature, relative humidity, and temperature-humidity index between on-farm measurements and official meteorological data.

    Science.gov (United States)

    Schüller, L K; Burfeind, O; Heuwieser, W

    2013-01-01

    The objectives of the study were to compare the climate conditions of 7 dairy farms with the climate recorded at the closest official meteorological station. Specifically, we set out to compare the ambient temperature, relative humidity, and the resulting temperature-humidity index (THI) from 7 different barns with those data obtained from the closest official meteorological stations and to compare the climate conditions between 4 different locations within 1 barn. Measures of correlation and agreement demonstrated that climate conditions differ significantly between the barn and the corresponding official meteorological stations as well as between 4 different locations inside 1 barn. The ambient temperature was higher (6.4±3.6°C) in the barn than at the official meteorological station. The relative humidity was higher at the official meteorological station (0.2±7.2%) than in the barn. The THI was higher (11.1±6.5) in the barn than at the official meteorological station. Days with an average THI≥72 were 64 and 4 out of 756 experimental d in the barn and at the official meteorological station, respectively. Also, in a comparison of 7 different barns, ambient temperature and THI were significantly higher than at the closest corresponding official meteorological station. These results indicate that climate conditions should be obtained from on-farm measurements to evaluate potential heat stress and to develop effective measures to abate heat stress of dairy cows. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Static force tests of a sharp leading edge delta-wing model at ambient and cryogenic temperatures with a description of the apparatus employed

    Science.gov (United States)

    Kilgore, R. A.; Davenport, E. E.

    1976-01-01

    A sharp leading edge delta-wing model was tested through an angle-of-attack range at Mach numbers of 0.75, 0.80, and 0.85 at both ambient and cryogenic temperatures in the Langley 1/3-meter transonic cryogenic tunnel. Total pressure was varied with total temperature in order to hold test Reynolds number constant at a given Mach number. Agreement between the aerodynamic data obtained at ambient and cryogenic temperatures indicates that flows with leading-edge vortex effects are duplicated properly at cryogenic temperatures. The test results demonstrate that accurate aerodynamic data can be obtained by using conventional force-testing techniques if suitable measures are taken to minimize temperature gradients across the balance and to keep the balance at ambient (warm) temperatures during cryogenic operation of the tunnel.

  15. Bar shoes and ambient temperature are risk factors for exercise-induced pulmonary haemorrhage in Thoroughbred racehorses.

    Science.gov (United States)

    Crispe, E J; Lester, G D; Robertson, I D; Secombe, C J

    2016-07-01

    Ambient temperature has been identified as a risk factor for exercise-induced pulmonary haemorrhage (EIPH) in racing Thoroughbreds. This warranted a more expansive investigation of climatic conditions on the incidence and severity of EIPH. The impact of other variables such as the type of bit used, tongue ties and nonstandard shoes has not been reported and also warrant investigation. To examine the effect of various climatic variables as contributing risk factors for EIPH. Other previously uninvestigated variables as well as standard track and population factors will also be examined. Cross-sectional study. Thoroughbred racehorses competing at metropolitan racetracks in Perth, Western Australia were examined 30-200 min post race with tracheobronchoscopy. Examination took place at 48 race meetings over a 12 month period. Examinations were graded (0-4), independently by two experienced veterinarians. Univariable analyses were performed and variables with a Pshoes were significantly associated with EIPH grades ≥1 (OR 6.35; 95% CI 2.17-18.54) and EIPH grades ≥2 (OR 2.72; 95% CI 1.3-5.68). Increasing race distance was significantly associated with EIPH grade ≥1 and increasing lifetime starts was significantly associated with EIPH grade ≥2. Ambient temperature is a risk factor for EIPH in Thoroughbred racehorses, with lower temperatures associated with increased risk. Bar shoes are a novel risk factor for EIPH in this population. © 2015 EVJ Ltd.

  16. Design and Application of Variable Temperature Setup for Scanning Electron Microscopy in Gases and Liquids at Ambient Conditions.

    Science.gov (United States)

    Al-Asadi, Ahmed S; Zhang, Jie; Li, Jianbo; Potyrailo, Radislav A; Kolmakov, Andrei

    2015-06-01

    Scanning electron microscopy (SEM) of nanoscale objects in dry and fully hydrated conditions at different temperatures is of critical importance in revealing details of their interactions with an ambient environment. Currently available WETSEM capsules are equipped with thin electron-transparent membranes and allow imaging of samples at atmospheric pressure, but do not provide temperature control over the sample. Here, we developed and tested a thermoelectric cooling/heating setup for WETSEM capsules to allow ambient pressure in situ SEM studies with a temperature range between -15 and 100°C in gaseous, liquid, and frozen conditions. The design of the setup also allows for correlation of the SEM with optical microscopy and spectroscopy. As a demonstration of the possibilities of the developed approach, we performed real-time in situ microscopy studies of water condensation on a surface of Morpho sulkowskyi butterfly wing scales. We observed that initial water nucleation takes place on top of the scale ridges. These results confirmed earlier discovery of a preexisting polarity gradient of the ridges of Morpho butterflies. Our developed thermoelectric cooling/heating setup for environmental capsules meets the diverse needs for in situ nanocharacterization in material science, catalysis, microelectronics, chemistry, and biology.

  17. Kinetics of Antibody Aggregation at Neutral pH and Ambient Temperatures Triggered by Temporal Exposure to Acid.

    Science.gov (United States)

    Imamura, Hiroshi; Honda, Shinya

    2016-09-15

    The purification process of an antibody in manufacturing involves temporal exposure of the molecules to low pH followed by neutralization-pH-shift stress-which causes aggregation. It remains unclear how aggregation triggered by pH-shift stress grows at neutral pH and how it depends on the temperature in an ambient range. We used static and dynamic light scattering to monitor the time-dependent evolution of the aggregate size of the pH-shift stressed antibody between 4.0 and 40.0 °C. A power-law relationship between the effective molecular weight and the effective hydrodynamic radius was found, indicating that the aggregates were fractal with a dimension of 1.98. We found that the aggregation kinetics in the lower-temperature range, 4.0-25.0 °C, were well described by the Smoluchowski aggregation equation. The temperature dependence of the effective aggregation rate constant gave 13 ± 1 kcal/mol of endothermic activation energy. Temporal acid exposure creates an enriched population of unfolded protein molecules that are competent of aggregating. Therefore, the energetically unfavorable unfolding step is not required and the aggregation proceeds faster. These findings provide a basis for predicting the growth of aggregates during storage under practical, ambient conditions.

  18. Design, Development and Implementation of the IR Signalling Techniques for Monitoring Ambient and Body Temperature in WBANs

    Directory of Open Access Journals (Sweden)

    Attiya Baqai

    2014-07-01

    Full Text Available Healthcare systems such as hospitals, homecare, telemedicine, and physical rehabilitation are expected to be revolutionized by WBAN (Wireless Body Area Networks. This research work aims to investigate, design, optimize, and demonstrate the applications of IR (Infra-Red communication systems in WBAN. It is aimed to establish a prototype WBAN system capable of measuring Ambient and Body Temperature using LM35 as temperature sensor and transmitting and receiving the data using optical signals. The corresponding technical challenges that have to be faced are also discussed in this paper. Investigations are carried out to efficiently design the hardware using low-cost and low power optical transceivers. The experimental results reveal the successful transmission and reception of Ambient and Body Temperatures over short ranges i.e. up to 3-4 meters. A simple IR transceiver with an LED (Light Emitting Diodes, TV remote control IC and Arduino microcontroller is designed to perform the transmission with sufficient accuracy and ease. Experiments are also performed to avoid interference from other sources like AC and TV remote control signals by implementing IR tags

  19. Spatial distribution of unspecified chronic kidney disease in El Salvador by crop area cultivated and ambient temperature.

    Science.gov (United States)

    VanDervort, Darcy R; López, Dina L; Orantes, Carlos M; Rodríguez, David S

    2014-04-01

    Chronic kidney disease of unknown etiology is occurring in various geographic areas worldwide. Cases lack typical risk factors associated with chronic kidney disease, such as diabetes and hypertension. It is epidemic in El Salvador, Central America, where it is diagnosed with increasing frequency in young, otherwise-healthy male farmworkers. Suspected causes include agrochemical use (especially in sugarcane fields), physical heat stress, and heavy metal exposure. To evaluate the geographic relationship between unspecified chronic kidney disease (unCKD) and nondiabetic chronic renal failure (ndESRD) hospital admissions in El Salvador with the proximity to cultivated crops and ambient temperatures. Data on unCKD and ndESRD were compared with environmental variables, crop area cultivated (indicator of agrochemical use) and high ambient temperatures. Using geographically weighted regression analysis, two model sets were created using reported municipal hospital admission rates are per thousand population for unCKD 2006-2010 and rates of ndESRD 2005-2010 [corrected]. These were assessed against local percent of land cultivated by crop (sugarcane, coffee, corn, cotton, sorghum, and beans) and mean maximum ambient temperature, with Moran's indices determining data clustering. Two-dimensional geographic models illustrated parameter spatial distribution. Bivariate geographically weighted regressions showed statistically significant correlations between percent area of sugarcane, corn, cotton, coffee, and bean cultivation, as well as mean maximum ambient temperature with both unCKD and ndESRD hospital admission rates. Percent area of sugarcane cultivation had greatest statistical weight (p ≤ 0.001; Rp2 = 0.77 for unCKD). The most statistically significant multivariate geographically weighted regression model for unCKD included percent area of sugarcane, cotton and corn cultivation (p ≤ 0.001; Rp2 = 0.80), while, for ndESRD, it included the percent area of sugarcane, corn

  20. International Normalized Ratio (INR), coagulation factor activities and calibrated automated thrombin generation - influence of 24 h storage at ambient temperature

    DEFF Research Database (Denmark)

    Christensen, T D; Jensen, C; Larsen, T B

    2010-01-01

    International Normalized Ratio (INR) measurements are used to monitor oral anticoagulation therapy with coumarins. Single coagulation factor activities and calibrated automated thrombin (CAT) generation are considered as more advanced methods for evaluating overall haemostatic capacity. The aims...... were to assess the variability of INR, coagulation factor activities, and CAT, during 24 h of storage of blood samples at ambient temperature. A total of 24 patients on stable coumarin treatment were followed prospectively for 6 weeks. INR was analyzed at 0, 6 and 24 h after blood sampling and 1-stage...

  1. 75 FR 57463 - Review of the Secondary National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides...

    Science.gov (United States)

    2010-09-21

    ... National Ambient Air Quality Standards for Oxides of Nitrogen and Oxides of Sulfur AGENCY: Environmental... Oxides of Nitrogen and Oxides of Sulfur: Second External Review Draft. The EPA is releasing this... for oxides of nitrogen (NO X ) and oxides of sulfur (SO X ). Because NO X , SO X , and their...

  2. Coolant and ambient temperature control for chillerless liquid cooled data centers

    Science.gov (United States)

    Chainer, Timothy J.; David, Milnes P.; Iyengar, Madhusudan K.; Parida, Pritish R.; Simons, Robert E.

    2016-02-02

    Cooling control methods include measuring a temperature of air provided to a plurality of nodes by an air-to-liquid heat exchanger, measuring a temperature of at least one component of the plurality of nodes and finding a maximum component temperature across all such nodes, comparing the maximum component temperature to a first and second component threshold and comparing the air temperature to a first and second air threshold, and controlling a proportion of coolant flow and a coolant flow rate to the air-to-liquid heat exchanger and the plurality of nodes based on the comparisons.

  3. On-Board State-of-Health Estimation at a Wide Ambient Temperature Range in Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Tiansi Wang

    2015-08-01

    Full Text Available A state-of-health (SOH estimation method for electric vehicles (EVs is presented with three main advantages: (1 it provides joint estimation of cell’s aging states in terms of power and energy (i.e., SOHP and SOHE—because the determination of SOHP and SOHE can be reduced to the estimation of the ohmic resistance increase and capacity loss, respectively, the ohmic resistance at nominal temperature will be taken as a health indicator, and the capacity loss is estimated based on a mechanistic model that is developed to describe the correlation between resistance increase and capacity loss; (2 it has wide applicability to various ambient temperatures—to eliminate the effects of temperature on the resistance, another mechanistic model about the resistance against temperature is presented, which can normalize the resistance at various temperatures to its standard value at the nominal temperature; and (3 it needs low computational efforts for on-board application—based on a linear equation of cell’s dynamic behaviors, the recursive least-squares (RLS algorithm is used for the resistance estimation. Based on the designed performance and validation experiments, respectively, the coefficients of the models are determined and the accuracy of the proposed method is verified. The results at different aging states and temperatures show good accuracy and reliability.

  4. Antimicrobial properties and the influence of temperature on secondary metabolite production in cold environment soil fungi

    Science.gov (United States)

    Yogabaanu, U.; Weber, Jean-Frederic Faizal; Convey, Peter; Rizman-Idid, Mohammed; Alias, Siti Aisyah

    2017-12-01

    The Arctic and Antarctic share environmental extremes. To survive in such environments, microbes such as soil fungi need to compete with or protect themselves effectively from other soil microbiota and to obtain the often scarce nutrients available, and many use secondary metabolites to facilitate this. We therefore (i) screened for antimicrobial properties of cold-environment Arctic and Antarctic soil fungi, and (ii) identified changes in the secreted secondary metabolite profiles of a subset of these strains in response to temperature variation. A total of 40 polar soil fungal strains from King George Island, maritime Antarctic and Hornsund, Svalbard, High Arctic, were obtained from the Malaysian National Antarctic Research Centre culture collections. The plug assay technique was used to screen for antimicrobial potential against Gram-positive and Gram-negative human pathogenic bacteria (Bacillus subtilis, B. cereus, Pseudomonas aeruginosa, Enterococcus faecalis and Escherichia coli). About 45% of the tested fungal strains showed antimicrobial activity against at least one tested microorganism. Three fungal isolates showed good bioactivity and were subjected to secondary metabolite profiling at different temperatures (4, 10, 15 and 28 °C). We observed a range of responses in fungal metabolite production when incubated at varying temperatures, confirming an influence of environmental conditions such as temperature on the production of secondary metabolites.

  5. Low-Temperature Positive Secondary Ion Mass Spectrometry of Neat and Argon-Diluted Organic Solids

    NARCIS (Netherlands)

    Jonkman, Harry T.; Michl, Josef; King, Robert N.; Andrade, Joseph D.

    1978-01-01

    Secondary ion mass spectrometry of neat solid propane, n-pentane, benzene, toluene, and of propane imbedded in an argon matrix were observed at temperatures varying from 10 to 110 K and show fragmentation patterns similar to those known from ordinary electron impact mass spectrometry. The effects of

  6. Application of tire chips to reduce the temperature of secondary geomembranes in municipal solid waste landfills.

    Science.gov (United States)

    Hoor, Azadeh; Rowe, R Kerry

    2012-05-01

    Heat generated by the biodegradation of waste and other chemical processes in a landfill can potentially affect the long-term performance of landfill liner system, in particular that of a high-density polyethylene geomembrane. In a double liner system, the difference in leachate exposure and temperature might improve the long-term performance of the secondary geomembrane compared to that of the primary geomembrane. However, in some cases, the temperature is likely to be high enough to substantially reduce the service-life of the secondary geomembrane. This study explores the possible effectiveness of using tire chips as thermal insulation between primary and secondary liners to reduce the temperature of secondary geomembranes as compared to traditional soil materials. Heat and contaminant migration analyses are performed for cases with no insulation and for cases in which a layer of soil or tire chips has been used as thermal insulation between the primary and secondary liners. The effect of insulation on prolonging the service-life of a secondary geomembrane and, consequently, on contaminant transport through a liner system is examined for the case of a volatile organic compound (dichloromethane) found in landfill leachate. The study suggests that the use of tire chips warrants consideration, however there are other practical issues that require consideration in the detailed design and construction of landfill liners. Issues such as finite service-life, low working temperature, excessive settlement, ability to generate internal heat, leaching of tire chips and limitations in performing electrical resistivity leak detection tests are identified. Copyright © 2012 Elsevier Ltd. All rights reserved.

  7. Environmental control of drilling mud discharge through dewatering in cold weather climates: effect of ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wojtanowicz, A. K. [Louisiana State Univ., Baton Rouge, LA (United States); Ye, Y. [Jianghan Petroleum Institute, Beijing, (China)

    1998-05-01

    Results of an experimental study of the effects of drilling mud temperature upon dewatering performance at various temperatures were presented. Three temperature ranges (from flowline temperature to room temperature, from room temperature to freezing point, and freeze/thaw, i.e. from -20 degrees C to 12 degrees C) were considered. Both unweighted and weighted fresh water muds and weighted salt water mud were tested using a sealed laboratory batch reactor, to prevent rapid vaporization of separated water at temperatures above 60 degrees C. Deep freezing was achieved by using ice or ice-salt baths. Net water removal was measured with a bench-top plate press under constant expression pressure of 270 kPa. Results showed that the freeze/thaw treatment process proved to be very effective, enhancing water removal by 34 to 39 per cent, and reducing waste mud volume by 64 to 72 per cent. No advantage to dewatering hot drilling mud from active systems was observed at temperatures above 21 degrees C. It was suggested that at temperatures under 21 degrees C, the waste drilling mud diverted from an active system should be dewatered when its temperature is still over 40 degrees C. to reduce the amount of chemicals needed for separation enhancement. 14 refs., 4 tabs., 4 figs.

  8. Ambient temperature effects on photo induced gonadal cycles and hormonal secretion patterns in Great Tits from three different breeding latitudes.

    Science.gov (United States)

    Silverin, Bengt; Wingfield, John; Stokkan, Karl-Arne; Massa, Renato; Järvinen, Antero; Andersson, Nils-Ake; Lambrechts, Marcel; Sorace, Alberto; Blomqvist, Donald

    2008-06-01

    The present study determines how populations of Great Tits (Parus major) breeding in southern, mid and northern European latitudes have adjusted their reproductive endocrinology to differences in the ambient temperature during the gonadal cycle. A study based on long-term breeding data, using the Colwell predictability model, showed that the start of the breeding season has a high predictability ( approximately 0.8-0.9) at all latitudes, and that the environmental information factor (I(e)) progressively decreased from mid Italy (I(e)>4) to northern Finland (I(e)photoperiodic initial predictive information (day length), becomes progressively more important in maintaining the predictability of the breeding season with decreasing latitude. This hypothesis was verified by exposing photosensitive Great Tits from northern Norway, southern Sweden and northern Italy to sub-maximal photo-stimulatory day lengths (13L:11D) under two different ambient temperature regimes (+4 degrees C and +20 degrees C). Changes in testicular size, plasma levels of LH and testosterone were measured. The main results were: (1) Initial testicular growth rate, as well as LH secretion, was affected by temperature in the Italian, but not in birds from the two Scandinavian populations. (2) Maximum testicular size, maximum LH and testosterone levels were maintained for a progressively shorter period of time with increasing latitude, regardless of whether the birds were kept on a low or a high ambient temperature. (3) In birds from all latitudes, the development of photorefractoriness, as indicated by testicular regression and a decrease in plasma levels of LH and testosterone, started much earlier (with the exception for LH Great Tits from northern Scandinavia) when kept on +20 degrees C than when kept on +4 degrees C. The prolonging effects of a low temperature was more pronounced in Mediterranean birds, than in birds from Scandinavia, and more pronounced in Great Tits from southern Scandinavia than

  9. Large scale synthesis and formation mechanism of silver nanoparticles in solid-state reactions at ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Aiqin, E-mail: zhangaiqin@zzuli.edu.cn [State Laboratory of Surface and Interface Science and Technology, Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Tian, Yakun; Xiao, Yuanhua; Sun, Yuan [State Laboratory of Surface and Interface Science and Technology, Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); Li, Feng [State Laboratory of Surface and Interface Science and Technology, Henan Collaborative Innovation Center of Environmental Pollution Control and Ecological Restoration, Zhengzhou University of Light Industry, Zhengzhou 450002 (China); American Advanced Nanotechnology, Houston, TX 77459 (United States)

    2015-07-15

    Highlights: • AgNPs were prepared by solid state reaction at ambient temperature. • Only silver nitrate and ascorbic acid were needed in this reaction. • The size of the AgNPs can be tuned conveniently. • Formation mechanism of the AgNPs was investigated. - Abstract: A one-step strategy for preparing Ag nanoparticles (AgNPs) on large scale is demonstrated successfully, based on solid-state reactions at ambient temperature. The environmentally friendly synthesis can be achieved by simply grinding AgNO{sub 3} and ascorbic acid (AA) for about 30 min without adding any solvent and organic protectors. The size of AgNPs can be readily controlled by adjusting the reaction parameters such as AgNO{sub 3}/AA molar ratio and reaction time. The nanostructures of AgNPs and their formation mechanism have been also investigated with XRD, FTIR, FESEM, HRTEM and HPLC–MS. It was found that AA can reduce Ag{sup +} into Ag{sup 0} to form AgNPs directly in accompanying with its first oxidation into 2,3-diketogulonic acid (2,3-DKG) and then a series of fragmentary species of 2,3-DKG.

  10. Comparative analysis of insect succession data from Victoria (Australia) using summary statistics versus preceding mean ambient temperature models.

    Science.gov (United States)

    Archer, Mel

    2014-03-01

    Minimum postmortem interval (mPMI) can be estimated with preceding mean ambient temperature models that predict carrion taxon pre-appearance interval. But accuracy has not been compared with using summary statistics (mean ± SD of taxon arrival/departure day, range, 95% CI). This study collected succession data from ten experimental and five control (infrequently sampled) pig carcasses over two summers (n = 2 experimental, n = 1 control per placement date). Linear and exponential preceding mean ambient temperature models for appearance and departure times were constructed for 17 taxa/developmental stages. There was minimal difference in linear or exponential model success, although arrival models were more often significant: 65% of linear arrival (r2 = 0.09–0.79) and exponential arrival models (r2 = 0.05–81.0) were significant, and 35% of linear departure (r2 = 0.0–0.71) and exponential departure models (r2 = 0.0–0.72) were significant. Performance of models and summary statistics for estimating mPMI was compared in two forensic cases. Only summary statistics produced accurate mPMI estimates.

  11. Thermal behavior of human eye in relation with change in blood perfusion, porosity, evaporation and ambient temperature.

    Science.gov (United States)

    Rafiq, Aasma; Khanday, M A

    2016-12-01

    Extreme environmental and physiological conditions present challenges for thermal processes in body tissues including multi-layered human eye. A mathematical model has been formulated in this direction to study the thermal behavior of the human eye in relation with the change in blood perfusion, porosity, evaporation and environmental temperatures. In this study, a comprehensive thermal analysis has been performed on the multi-layered eye using Pennes' bio-heat equation with appropriate boundary and interface conditions. The variational finite element method and MATLAB software were used for the solution purpose and simulation of the results. The thermoregulatory effect due to blood perfusion rate, porosity, ambient temperature and evaporation at various regions of human eye was illustrated mathematically and graphically. The main applications of this model are associated with the medical sciences while performing laser therapy and other thermoregulatory investigation on human eye. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. The burden of ambient temperature on years of life lost: A multi-community analysis in Hubei, China.

    Science.gov (United States)

    Zhang, Yunquan; Yu, Chuanhua; Peng, Minjin; Zhang, Lan

    2018-04-15

    Compared with death rates, years of life lost (YLL) has been widely used as a more informative indicator to quantify the burden of premature death. In the context of global climate change, existing evidence linking ambient temperatures and YLL was very scarce across the globe. Daily mortality and meteorological data during 2009-2012 were obtained from 12 communities across Hubei Province in central China. A two-stage approach was used for statistical analysis. At the first stage, a generalized linear regression combined with distributed lag non-linear model was applied to estimate community-specific temperature-YLL associations. A second-stage multivariable meta-analysis was then conducted to pool the community-specific estimates of temperature-related effects on YLL. A pooled J- or U-shaped association was observed between ambient temperature and YLL due to different mortality categories. Heat effects occurred immediately and only persisted for several days, whereas cold effects were delayed and much longer-lasting. At the provincial level, heat effect (per 1°C increase from 75th to 99th percentile of temperature) at lag 0-2days and cold effect (per 1°C decrease from 25th to 1st percentile of temperature) at lag 0-21days was associated with an increase of 1.91% (95% CI: 0.83, 3.00) and 5.09% (2.79, 7.40) in YLL due to non-accidental deaths, respectively. Much greater effect estimates of cold than heat were also observed for other mortality-specific YLLs (except for respiratory mortality). Heat effects on YLL were higher for males and the youth, while cold effects were greater for females and the elderly. Additionally, relatively stronger associations between heat, cold and YLL were consistently observed in low-educated persons. This multi-community study strengthened the evidence that both cold and hot temperatures were associated with increased years of life lost. Our findings may have important implications for better understanding the burden of premature

  13. Effect of ambient temperature and sodium bicarbonate supplementation on water and electrolyte balances in dry and lactating Holstein cows.

    Science.gov (United States)

    Khelil-Arfa, H; Faverdin, P; Boudon, A

    2014-01-01

    The aim of this study was to quantify the effect of the interaction between 2 constant ambient temperatures [thermoneutrality (TN; 15°C) and high temperature (HT; 28°C)] and 2 levels of Na bicarbonate supplementation [calculated to provide diet Na contents of 0.20%DM (Na-) and 0.50%DM (Na+)] on water partitioning in dairy cows. Treatments were compared on 4 dry and 4mid-lactation Holstein cows according to 2 Latin squares (1 for each physiological stage) over the course of 4 periods of 15d. Diets consisted of a total mixed ration based on maize silage. Dry cows were restricted to their protein and energy requirements, whereas lactating cows were fed ad libitum. The daily average temperature-humidity index was 59.4 for TN and 73.2 for HT. Lactating and dry cows had higher vaginal temperatures at HT than at TN, but the increase was more pronounced in lactating cows (+1.05 vs. +0.12°C for vaginal temperature, respectively). Dry matter intake (DMI) of lactating cows decreased by 2.3kg/d at HT. Free water intake (FWI) and estimated volume of water lost to evaporation increased at HT in both lactating and dry cows; no interactions were observed between temperature and physiological stage. When expressed as a proportion of DMI, the increase in evaporation that occurred with increasing temperature was completely compensated for by an increase in FWI for both physiological stages. The urinary water excretion increased slightly at HT in lactating cows but not in dry cows, which may be related to the low chloride content of the offered diet. High Na supplementation increased DMI slightly in lactating cows, but milk yield was not affected. Sodium supplementation did not limit the decrease in DMI observed in lactating cows at HT; this observation is likely due to the high diet electrolyte balance of the offered diets. Sodium supplementation increased FWI in lactating cows and urinary flow in both physiological states. The interaction between ambient temperature and Na

  14. Model Study of the Influence of Ambient Temperature and Installation Types on Surface Temperature Measurement by Using a Fiber Bragg Grating Sensor.

    Science.gov (United States)

    Liu, Yi; Zhang, Jun

    2016-07-01

    Surface temperature is an important parameter in clinical diagnosis, equipment state control, and environmental monitoring fields. The Fiber Bragg Grating (FBG) temperature sensor possesses numerous significant advantages over conventional electrical sensors, thus it is an ideal choice to achieve high-accuracy surface temperature measurements. However, the effects of the ambient temperature and installation types on the measurement of surface temperature are often overlooked. A theoretical analysis is implemented and a thermal transfer model of a surface FBG sensor is established. The theoretical and simulated analysis shows that both substrate strain and the temperature difference between the fiber core and hot surface are the most important factors which affect measurement accuracy. A surface-type temperature standard setup is proposed to study the measurement error of the FBG temperature sensor. Experimental results show that there are two effects influencing measurement results. One is the "gradient effect". This results in a positive linear error with increasing surface temperature. Another is the "substrate effect". This results in a negative non-linear error with increasing surface temperature. The measurement error of the FBG sensor with single-ended fixation are determined by the gradient effect and is a linear error. It is not influenced by substrate expansion. Thus, it can be compensated easily. The measurement errors of the FBG sensor with double-ended fixation are determined by the two effects and the substrate effect is dominant. The measurement error change trend of the FBG sensor with fully-adhered fixation is similar to that with double-ended fixation. The adhesive layer can reduce the two effects and measurement error. The fully-adhered fixation has lower error, however, it is easily affected by substrate strain. Due to its linear error and strain-resistant characteristics, the single-ended fixation will play an important role in the FBG sensor

  15. Model Study of the Influence of Ambient Temperature and Installation Types on Surface Temperature Measurement by Using a Fiber Bragg Grating Sensor

    Directory of Open Access Journals (Sweden)

    Yi Liu

    2016-07-01

    Full Text Available Surface temperature is an important parameter in clinical diagnosis, equipment state control, and environmental monitoring fields. The Fiber Bragg Grating (FBG temperature sensor possesses numerous significant advantages over conventional electrical sensors, thus it is an ideal choice to achieve high-accuracy surface temperature measurements. However, the effects of the ambient temperature and installation types on the measurement of surface temperature are often overlooked. A theoretical analysis is implemented and a thermal transfer model of a surface FBG sensor is established. The theoretical and simulated analysis shows that both substrate strain and the temperature difference between the fiber core and hot surface are the most important factors which affect measurement accuracy. A surface-type temperature standard setup is proposed to study the measurement error of the FBG temperature sensor. Experimental results show that there are two effects influencing measurement results. One is the “gradient effect”. This results in a positive linear error with increasing surface temperature. Another is the “substrate effect”. This results in a negative non-linear error with increasing surface temperature. The measurement error of the FBG sensor with single-ended fixation are determined by the gradient effect and is a linear error. It is not influenced by substrate expansion. Thus, it can be compensated easily. The measurement errors of the FBG sensor with double-ended fixation are determined by the two effects and the substrate effect is dominant. The measurement error change trend of the FBG sensor with fully-adhered fixation is similar to that with double-ended fixation. The adhesive layer can reduce the two effects and measurement error. The fully-adhered fixation has lower error, however, it is easily affected by substrate strain. Due to its linear error and strain-resistant characteristics, the single-ended fixation will play an

  16. Physical mechanism or evolutionary trade-off? Factors dictating the relationship between metabolic rate and ambient temperature in carabid beetles.

    Science.gov (United States)

    Gudowska, Agnieszka; Schramm, Bartosz W; Czarnoleski, Marcin; Kozłowski, Jan; Bauchinger, Ulf

    2017-08-01

    The tight association between ambient temperature (T) and metabolic rate (MR) is a common occurrence in ectotherms, but the determinants of this association are not fully understood. This study examined whether the relationship between MR and T is the same among individuals, as predicted by the Universal Temperature Dependence hypothesis, or whether this relationship differs between them. We used flow-through respirometry to measure standard MR and to determine gas exchange patterns for 111 individuals of three Carabidae species which differ in size (Abax ovalis, Carabus linnei and C. coriaceus), exposed to four different temperatures (ten individuals of each species measured at 6, 11, 16 and 21°C). We found a significant interaction between ln body mass and the inverse of temperature, indicating that in a given species, the effect of temperature on MR was weaker in larger individuals than in smaller individuals. Overall, this finding shows that the thermal dependence of MR is not body mass invariant. We observed three types of gas exchange patterns among beetles: discontinuous, cyclic and continuous. Additionally, the appearance of these patterns was associated with MR and T. Evolution in diverse terrestrial environments could affect diverse ventilation patterns, which accommodate changes in metabolism in response to temperature variation. In conclusion, explaining the variance in metabolism only through fundamental physical laws of thermodynamics, as predicted by the Universal Temperature Dependence hypothesis, appears to oversimplify the complexity of nature, ignoring evolutionary trade-offs that should be taken into account in the temperature - metabolism relationship. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Effects of high ambient temperature on ambulance dispatches in different age groups in Fukuoka, Japan.

    Science.gov (United States)

    Kotani, Kazuya; Ueda, Kayo; Seposo, Xerxes; Yasukochi, Shusuke; Matsumoto, Hiroko; Ono, Masaji; Honda, Akiko; Takano, Hirohisa

    2018-01-01

    The elderly population has been the primary target of intervention to prevent heat-related illnesses. According to the literature, the highest risks have been observed among the elderly in the temperature-mortality relationship. However, findings regarding the temperature-morbidity relationship are inconsistent. This study aimed to examine the association of temperature with ambulance dispatches due to acute illnesses, stratified by age group. Specifically, we explored the optimum temperature, at which the relative health risks were found to be the lowest, and quantified the health risk associated with higher temperatures among different age groups. We used the data for ambulance dispatches in Fukuoka, Japan, during May and September from 2005 to 2012. The data were grouped according to age in 20-year increments. We explored the pattern of the association of ambulance dispatches with temperature using a smoothing spline curve to identify the optimum temperature for each age group. Then, we applied a distributed lag nonlinear model to estimate the risks of the 85th-95th percentile temperature relative to the overall optimum temperature, for each age group. The relative risk of ambulance dispatches at the 85th and 95th percentile temperature for all ages was 1.08 [95% confidence interval (CI): 1.05, 1.12] and 1.12 (95% CI: 1.08, 1.16), respectively. In comparison, among age groups, the optimum temperature was observed as 25.0°C, 23.2°C, and 25.3°C for those aged 0-19, 60-79, and ≥80, respectively. The optimum temperature could not be determined for those aged 20-39 and 40-59. The relative risks of high temperature tended to be higher for those aged 20-39 and 40-59 than those for other age groups. We did not find any definite difference in the effect of high temperature on ambulance dispatches for different age groups. However, more measures should be taken for younger and middle-aged people to avoid heat-related illnesses.

  18. Ambient temperature effects on growth of milkfish (Chanos chanos) at aquaculture scale in Blanakan, West Java

    Science.gov (United States)

    A'yun, Q.; Takarina, N. D.

    2017-07-01

    Growth and survival of fishes can be influenced by temperature [1]. Variation among size like weight and length could be the preference how temperature works on growth of fishes [2]. This could be key factor in determining in production as well as market demand since people like heavy and large fishes. The main purpose of this study was to determine the effects of temperature on the growth of milkfish (Chanos Chanos) on weight and length parameters in fish farms Blanakan. This study conducted to assess the optimal temperature for the growth of fish of different sizes to optimize the culture conditions for raising milkfishes in scale cultivation in Blanakan, West Java. Milkfishes were reared in the aquaculture Blanakan ponds because they can adapt very well. The weight and length of milkfishes were measured together with water temperature. The results showed the temperature min (tmin) and max (tmax) were ranged from 29-35 °C. Based on the result, there were significant differences in mean weight (p = 0.00) between temperature with the fish reared in tmax group having the lowest mean weight (99.87±11.51 g) and fish reared in tmin group having the highest mean weight (277.17±33.76 g). Likewise, the significant differences were also observed in mean length (p = 0.00) between temperature with the fish reared in tmax group having the lowest mean length (176.50±12.50 mm) and fish reared in tmin group having the highest mean length (183.60±23.86 mm). Therefore, this paper confirmed the significant effects of temperature on the fish growth reared in aquaculture ponds. More, maintaining aquaculture to lower temperature can be considered as way to keep growth of milkfish well.

  19. Statistical relationship between ambient temperature and diarrheal diseases in Coatzacoalcos, Veracruz (Mexico

    Directory of Open Access Journals (Sweden)

    Irving Rafael Méndez Pérez

    2011-02-01

    Full Text Available To research the relationship between room temperature and diarrhea diseases, we statistically analyzed the showed diarrhea's cases in Sanitary Jurisdiction from Coatzacoalcos, Ver., during the period 2000-2003. By means of time series and a model of linear regression, we have find out that the variability in the frequency of diarrheas can be explained in terms of 40% by the temperature. Therefore, the frequency of the diarrhea's cases increases during June, July and August. On the other hand in rainy seasons (September, October and November both diarrhea's cases and temperatures fall linearly.

  20. Interactive effects of ambient temperature and light sources at high relative humidity on growth performance and blood physiological variables in broilers grown to 42 day of age

    Science.gov (United States)

    The interactive effects of ambient temperature and light sources at high relative humidity on growth performance and blood physiological reactions in broilers grown to 42 day of age were investigated. The experiment consisted of 2 levels (Moderate=21.1, High=26.7 °C) of temperatures and 2 light sour...

  1. The effect of ambient temperature on type-2-diabetes: case-crossover analysis of 4+ million GP consultations across England.

    Science.gov (United States)

    Hajat, S; Haines, A; Sarran, C; Sharma, A; Bates, C; Fleming, L E

    2017-07-12

    Given the double jeopardy of global increases in rates of obesity and climate change, it is increasingly important to recognise the dangers posed to diabetic patients during periods of extreme weather. We aimed to characterise the associations between ambient temperature and general medical practitioner consultations made by a cohort of type-2 diabetic patients. Evidence on the effects of temperature variation in the primary care setting is currently limited. Case-crossover analysis of 4,474,943 consultations in England during 2012-2014, linked to localised temperature at place of residence for each patient. Conditional logistic regression was used to assess associations between each temperature-related consultation and control days matched on day-of-week. There was an increased odds of seeking medical consultation associated with high temperatures: Odds ratio (OR) = 1.097 (95% confidence interval = 1.041, 1.156) per 1 °C increase above 22 °C. Odds during low temperatures below 0 °C were also significantly raised: OR = 1.024 (1.019, 1.030). Heat-related consultations were particularly high among diabetics with cardiovascular comorbidities: OR = 1.171 (1.031, 1.331), but there was no heightened risk with renal failure or neuropathy comorbidities. Surprisingly, lower odds of heat-related consultation were associated with the use of diuretics, anticholinergics, antipsychotics or antidepressants compared to non-use, especially among those with cardiovascular comorbidities, although differences were not statistically significant. Type-2 diabetic patients are at increased odds of medical consultation during days of temperature extremes, especially during hot weather. The common assumption that certain medication use heightens the risk of heat illness was not borne-out by our study on diabetics in a primary care setting and such advice may need to be reconsidered in heat protection plans.

  2. Physical exercise-induced changes in the core body temperature of mice depend more on ambient temperature than on exercise protocol or intensity

    Science.gov (United States)

    Wanner, Samuel Penna; Costa, Kátia Anunciação; Soares, Anne Danieli Nascimento; Cardoso, Valbert Nascimento; Coimbra, Cândido Celso

    2014-08-01

    The mechanisms underlying physical exercise-induced hyperthermia may be species specific. Therefore, the present study aimed to investigate the effects of exercise intensity and ambient temperature on the core body temperature ( T core) of running mice, which provide an important experimental model for advancing the understanding of thermal physiology. We evaluated the influence of different protocols (constant- or incremental-speed exercises), treadmill speeds and ambient temperatures ( T a) on the magnitude of exercise-induced hyperthermia. To measure T core, a telemetric sensor was implanted in the abdominal cavity of male adult Swiss mice under anesthesia. After recovering from the surgery, the animals were familiarized to running on a treadmill and then subjected to the different running protocols and speeds at two T a: 24 °C or 34 °C. All of the experimental trials resulted in marked increases in T core. As expected, the higher-temperature environment increased the magnitude of running-induced hyperthermia. For example, during incremental exercise at 34 °C, the maximal T core achieved was increased by 1.2 °C relative to the value reached at 24 °C. However, at the same T a, neither treadmill speed nor exercise protocol altered the magnitude of exercise-induced hyperthermia. We conclude that T core of running mice is influenced greatly by T a, but not by the exercise protocols or intensities examined in the present report. These findings suggest that the magnitude of hyperthermia in running mice may be regulated centrally, independently of exercise intensity.

  3. Germination of tropical forage seeds stored for six years in ambient and controlled temperature and humidity conditions in Thailand

    Directory of Open Access Journals (Sweden)

    Michael D. Hare

    2018-01-01

    Full Text Available The germination performances of fresh seed lots were determined for 5 tropical forage species: Mulato II hybrid brachiaria [Urochloa ruziziensis (syn. Brachiaria ruziziensis x U. decumbens (syn. B. decumbens x U. brizantha (syn. B. brizantha], Mombasa guinea [Megathyrsus maximus (syn. Panicum maximum], Tanzania guinea [M. maximus (syn. P. maximum], Ubon paspalum (Paspalum atratum and Ubon stylo (Stylosanthes guianensis, stored under ambient conditions in Thailand (mean monthly temperatures 23‒34 ºC; mean monthly relative humidity 40‒92% or in a cool room (18‒20 ºC and 50% relative humidity for up to 6 years. The first paper of this study showed all seeds, except unscarified Ubon stylo seed, were dead after a single year of storage in ambient conditions. This second paper shows that cool-room storage extended seed viability, but performance varied considerably between species. Germination percentage under laboratory conditions declined to below 50%, after 3 years storage for Mombasa guinea seed and Tanzania guinea seed, 4 years for Ubon paspalum seed and 4‒5 years for Mulato II seed. Ubon stylo seed maintained high germination for 5 years, in both cool-room storage (96% and ambient-room storage (84%. Apparent embryo dormancy in acid-scarified Mulato II seed steadily increased with time in cool-storage and this seed had to be acid-scarified again each year at the time of germination testing to overcome dormancy. Physical dormancy of Mulato II seeds, imposed by the tightly bound lemma and palea in unscarified seed, was not overcome by length of time in cool-storage and these seeds had to be acid-scarified to induce germination. Hardseeded percentage in Ubon stylo seed remained high throughout the study and could be overcome only by acid-scarification. The difficulties of maintaining acceptable seed germination percentages when storing forage seeds in the humid tropics are discussed.

  4. Examining the Effects of Ambient Temperature on Pre-Term Birth in Central Australia

    Directory of Open Access Journals (Sweden)

    Supriya Mathew

    2017-02-01

    Full Text Available Preterm birth (born before 37 completed weeks of gestation is one of the leading causes of death among children under 5 years of age. Several recent studies have examined the association between extreme temperature and preterm births, but there have been almost no such studies in arid Australia. In this paper, we explore the potential association between exposures to extreme temperatures during the last 3 weeks of pregnancy in a Central Australian town. An immediate effect of temperature exposure is observed with an increased relative risk of 1%–2% when the maximum temperature exceeded the 90th percentile of the summer season maximum temperature data. Delayed effects are also observed closer to 3 weeks before delivery when the relative risks tend to increase exponentially. Immediate risks to preterm birth are also observed for cold temperature exposures (0 to –6 °C, with an increased relative risk of up to 10%. In the future, Central Australia will face more hot days and less cold days due to climate change and hence the risks posed by extreme heat is of particular relevance to the community and health practitioners.

  5. How Does Ambient Air Temperature Affect Diabetes Mortality in Tropical Cities?

    Science.gov (United States)

    Seposo, Xerxes T; Dang, Tran Ngoc; Honda, Yasushi

    2017-04-05

    Diabetes is well-known as one of the many chronic diseases that affect different age groups. Currently, most studies that evaluated the effects of temperature on diabetes mortality focused on temperate and subtropical settings, but no study has been conducted to assess the relationship in a tropical setting. We conducted the first multi-city study carried out in tropical cities, which evaluated the temperature-diabetes relationship. We collected daily diabetes mortality (ICD E10-E14) of four Philippine cities from 2006 to 2011. Same period meteorological data were obtained from the National Oceanic and Atmospheric Administration. We used a generalized additive model coupled with a distributed lag non-linear model (DLNM) in determining the relative risks. Results showed that both low and high temperatures pose greater risks among diabetics. Likewise, the study was able to observe the: (1) high risk brought about by low temperature, aside from the largely observed high risks by high temperature; and (2) protective effects in low temperature percentile. These results provide significant policy implications with strategies related to diabetes risk groups in relation to health service and care strategies.

  6. Increasing Gas Hydrate Formation Temperature for Desalination of High Salinity Produced Water with Secondary Guests

    Energy Technology Data Exchange (ETDEWEB)

    Cha, Jong-Ho; Seol, Yongkoo

    2013-10-07

    We suggest a new gas hydrate-based desalination process using water-immiscible hydrate formers; cyclopentane (CP) and cyclohexane (CH) as secondary hydrate guests to alleviate temperature requirements for hydrate formation. The hydrate formation reactions were carried out in an isobaric condition of 3.1 MPa to find the upper temperature limit of CO2 hydrate formation. Simulated produced water (8.95 wt % salinity) mixed with the hydrate formers shows an increased upper temperature limit from -2 °C for simple CO2 hydrate to 16 and 7 °C for double (CO2 + CP) and (CO2 + CH) hydrates, respectively. The resulting conversion rate to double hydrate turned out to be similar to that with simple CO2 hydrate at the upper temperature limit. Hydrate formation rates (Rf) for the double hydrates with CP and CH are shown to be 22 and 16 times higher, respectively, than that of the simple CO2 hydrate at the upper temperature limit. Such mild hydrate formation temperature and fast formation kinetics indicate increased energy efficiency of the double hydrate system for the desalination process. Dissociated water from the hydrates shows greater than 90% salt removal efficiency for the hydrates with the secondary guests, which is also improved from about 70% salt removal efficiency for the simple hydrates.

  7. The Effect of Ambient Temperatures of Two Threatened Caribbean Coral Species: a Proteomic Study

    Science.gov (United States)

    Ricaurte, M.; Schizas, N. V.; Weil, E.; Ciborowski, P.; Boukli, N. M.

    2016-02-01

    Coral reefs are among the most valuable ecosystems on the earth. Increasing water temperatures as a consequence of global warming have been identified, as an overriding cause of coral decline (e.g. increased incidence of diseases, bleaching), and one of the regions that has been identified vulnerable to climatic changes, is the Caribbean. Laboratory experiments have shown negative effects of different temperatures in coral growth, larval and adult survival, and gene expression. In order to understand the molecular and cellular basis in the protein regulation during changes in temperature in the field, a comparative proteomic analysis associated with thermal fluctuations was made from wet and dry season of 2014. In the study, we investigated alterations in proteins of Acropora palmata and Orbicella faveolata by two-dimensional gel electrophoresis (2D-GE) followed by liquid chromatography-tandem mass spectrometry, protein identification, and confirmation at the gene expression level by qRT-PCR.Proteomes of related samples demonstrated 195 differentially expressed proteins (DEP) in A. palmata during dry season and 108 (DEP) during wet season of 2014. O. faveolata overexpressed 62 (DEP) in dry season and 190 (DEP) during wet season of 2014. All proteins had a two-fold or greater change in expression due to temperature, altering several components of the cellular stress response that include chaperones, stress proteins, antioxidant enzymes, proteases, cytoskeletal and apoptosis regulating proteins. Our results suggest that A. palmata and O. faveolata display a distinct response by expressing these key protein signatures in dry and wet season. This proteomic approach may open new avenues of research to detect potential early biomarkers involved in response to these stressors, during seasonal changes in water temperatures. The results provide insight into targets and mechanistic strategies to detect potential markers involved in response to temperature change for A

  8. How Does Ambient Air Temperature Affect Diabetes Mortality in Tropical Cities?

    Directory of Open Access Journals (Sweden)

    Xerxes T. Seposo

    2017-04-01

    Full Text Available Diabetes is well-known as one of the many chronic diseases that affect different age groups. Currently, most studies that evaluated the effects of temperature on diabetes mortality focused on temperate and subtropical settings, but no study has been conducted to assess the relationship in a tropical setting. We conducted the first multi-city study carried out in tropical cities, which evaluated the temperature–diabetes relationship. We collected daily diabetes mortality (ICD E10–E14 of four Philippine cities from 2006 to 2011. Same period meteorological data were obtained from the National Oceanic and Atmospheric Administration. We used a generalized additive model coupled with a distributed lag non-linear model (DLNM in determining the relative risks. Results showed that both low and high temperatures pose greater risks among diabetics. Likewise, the study was able to observe the: (1 high risk brought about by low temperature, aside from the largely observed high risks by high temperature; and (2 protective effects in low temperature percentile. These results provide significant policy implications with strategies related to diabetes risk groups in relation to health service and care strategies.

  9. Effects of ambient temperature, humidity, and other meteorological variables on hospital admissions for angina pectoris.

    Science.gov (United States)

    Abrignani, Maurizio G; Corrao, Salvatore; Biondo, Giovan B; Lombardo, Renzo M; Di Girolamo, Paola; Braschi, Annabella; Di Girolamo, Alberto; Novo, Salvatore

    2012-06-01

    Seasonal peaks in cardiovascular disease incidence have been widely reported, suggesting weather has a role. The aim of our study was to determine the influence of climatic variables on angina pectoris hospital admissions. We correlated the daily number of angina cases admitted to a western Sicilian hospital over a period of 12 years and local weather conditions (temperature, humidity, wind force and direction, precipitation, sunny hours and atmospheric pressure) on a day-to-day basis. A total of 2459 consecutive patients were admitted over the period 1987-1998 (1562 men, 867 women; M/F - 1:8). A seasonal variation was found with a noticeable winter peak. The results of Multivariate Poisson analysis showed a significant association between the daily number of angina hospital admission, temperature, and humidity. Significant incidence relative ratios (95% confidence intervals/measure unit) were, in males, 0.988 (0.980-0.996) (p = 0.004) for minimal temperature, 0.990 (0.984-0.996) (p = 0.001) for maximal humidity, and 1.002 (1.000-1.004) (p = 0.045) for minimal humidity. The corresponding values in females were 0.973 (0.951-0.995) (p < 0.017) for maximal temperature and 1.024 (1.001-1.048) (p = 0.037) for minimal temperature. Environmental temperature and humidity may play an important role in the pathogenesis of angina, although it seems different according to the gender. These data may help to understand the mechanisms that trigger ischemic events and to better organize hospital assistance throughout the year.

  10. All-solid-state lithium-oxygen battery with high safety in wide ambient temperature range

    OpenAIRE

    Hirokazu Kitaura; Haoshen Zhou

    2015-01-01

    There is need to develop high energy storage devices with high safety to satisfy the growing industrial demands. Here, we show the potential to realize such batteries by assembling a lithium-oxygen cell using an inorganic solid electrolyte without any flammable liquid or polymer materials. The lithium-oxygen battery using Li1.575Al0.5Ge1.5(PO4)3 solid electrolyte was examined in the pure oxygen atmosphere from room temperature to 120??C. The cell works at room temperature and first full disch...

  11. Investigation of structural and magnetic properties of rapidly-solidified iron-silicon alloys at ambient and elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Jayaraman, T. V.; Meka, V. M.; Jiang, X.; Overman, N. R.; Doyle, J.; Shield, J. E.; Mathaudhu, S. N.

    2018-04-01

    In this work, we investigated the ambient temperature structural properties (~300 K) and the ambient and high temperature (up to 900 K) direct current (DC) magnetic properties of melt-spun Fe-x wt.% Si (x = 3, 5, & 8) alloys. The wheel surface speeds selected for the study were 30 m/s and 40 m/s. The thickness, width, lattice parameter, saturation magnetization (MS), and intrinsic coercivity (HCI) of the melt spun ribbons are presented and compared with data in the literature. The ribbons produced at the lower wheel surface speed (30 m/s) were continuous having relatively uniform edges compared to the ribbons produced at the higher wheel surface speed. The thickness and the width of the melt-spun ribbons ranged between ~15-60 μm and 500-800 μm, respectively. The x-ray diffraction spectra of the melt-spun ribbons indicated the presence of disordered α-phase, irrespective of the composition, and the wheel-surface speed. The lattice parameter decreased gradually as a function of increasing silicon content from ~0.2862 nm (Fe-3 wt.% Si) to ~0.2847 nm (Fe-8 wt.% Si). Wheel surface speed was not shown to have a significant effect on the magnetization, but primarily impacted the ribbon structure. A decreasing trend in the saturation magnetization was observed as a function of increased silicon content. The intrinsic coercivity of the melt-spun alloys ranged between ~50 to 200 A/m. Elevated temperature evaluation of the magnetization in the case of Fe-3 & 5 wt.% Si alloy ribbons was distinctly different from the Fe-8 wt.% Si alloy ribbons. The curves of the as-prepared Fe-3 wt.% Si and Fe-5 wt.% Si alloy ribbons were irreversible while that of Fe-8 wt.% Si was reversible. The MS for any of the combinations of wheel surface speed and composition decreased monotonically with the increase in temperature (from 300 – 900 K). The percentage decrease in MS from 300 K to 900 K for the Fe-3 wt.% Si and Fe-5 wt.% Si alloys was ~19-22 %, while the percentage decrease in the same

  12. Mapping the orthorhombic-to-tetragonal transition at ambient temperature in YBa2Cu3O/sub y/ ceramics

    International Nuclear Information System (INIS)

    The orthorhombic-to-tetragonal transition at ambient temperature in YBa 2 Cu 3 O/sub y/ ceramics is empirically mapped as a function of oxygen content (y) based on published neutron and x-ray diffraction studies. On approaching the transition region (y∼6.5) from the orthorhombic phase, there is a noticeable anomaly in the c-axis length, a smooth evolution of the b axis, and a rather abrupt transition of the a axis (the axis along which oxygen deficiency obtains at larger values of y in the orthorhombic phase). Finally, the empirical method developed here for ascertaining oxygen content from crystallographic data is compared to neutron, hydrogen reduction, and iodometric titration results for several metastable YBa 2 Cu 3 O/sub y/ ceramics and Fe- and Co-doped materials

  13. Effects of developmental age, ambient temperature, and dietary alterations on delta(12) desaturase activity in the house cricket, Acheta domesticus.

    Science.gov (United States)

    Batcabe, J P; Howell, J D; Blomquist, G J; Borgeson, C E

    2000-07-01

    Double bond formation in polyunsaturated fatty acids (PUFA) is mediated by desaturase enzymes. Certain insect species have been found to possess a Delta(12) desaturase, previously thought to occur exclusively in plants. We have begun to characterize this enzyme to determine its relatedness to those found in plants and animals. Desaturase activity can be altered significantly by a number of environmental factors in protozoa, cyanobacteria, plants, fish, and rats. We present evidence here that Delta(12) desaturase activity in Acheta domesticus is affected by developmental stage, starvation, dietary alterations, and fluctuations in ambient temperature. Highest activity is observed during the middle of the penultimate instar and 3 to 6 days after adult emergence. Starvation markedly decreases Delta(12) activity, whereas resumption of feeding on fat-free or low fat diets increases activity.

  14. Closing the Loop - Utilization of Secondary Resources by Low Temperature Thermal Gasification

    OpenAIRE

    Thomsen, Tobias Pape; Ahrenfeldt, Jesper; Henriksen, Ulrik Birk; Hauggaard-Nielsen, Henrik; Holm, Jens Kai

    2016-01-01

    This study addresses certain issues related to unsustainable management of secondary resources like organic waste, sewage sludge and residues from agriculture and industry with a focus on losses of nonfossil energy potential and valuable elements. In this context it is investigated how suitable application of low temperature thermal gasification could be applied to reduce the environmental impact of such management systems and increase the value and positive awareness of the resources in ques...

  15. Secondary heat exchanger design and comparison for advanced high temperature reactor

    International Nuclear Information System (INIS)

    Sabharwall, P.; Kim, E. S.; Siahpush, A.; McKellar, M.; Patterson, M.

    2012-01-01

    Next generation nuclear reactors such as the advanced high temperature reactor (AHTR) are designed to increase energy efficiency in the production of electricity and provide high temperature heat for industrial processes. The efficient transfer of energy for industrial applications depends on the ability to incorporate effective heat exchangers between the nuclear heat transport system and the industrial process heat transport system. This study considers two different types of heat exchangers - helical coiled heat exchanger and printed circuit heat exchanger - as possible options for the AHTR secondary heat exchangers with distributed load analysis and comparison. Comparison is provided for all different cases along with challenges and recommendations. (authors)

  16. [The Relationship Study between Expressions of P2X5 Receptor and Deficiency-cold Syndrome/Deficiency-heat Syndrome at Various Ambient Temperatures].

    Science.gov (United States)

    Yang, Li-ping; Yu, Hong-jie; Huang, Rui; Li, Xin-min; Zhan, Xiang-hong; Hou, Jun-lin

    2015-05-01

    To detect the expression of the peripheral blood P2X5 receptor at various ambient temperatures, and to explore its relationship with deficiency-cold syndrome and deficiency-heat syndrome. Subjects were selected by questionnaire and expert diagnosis, and assigned to the normal control group, the deficiency-cold syndrome group, and the deficiency-heat syndrome group, 20 in each group. 5 mL venous blood was collected at room temperature (25 °C) and cold temperature (-4-5 °C) respectively. Then the expression of P2X5 receptor was relatively quantified by real-time fluorescence quantitative PCR, and compared at room temperature and cold temperature respectively. The expression of P2X5 receptor in deficiency-cold syndrome and deficiency-heat syndrome groups was lower than that in the normal control group at room temperature (P cold temperature in the deficiency-cold syndrome group than in the normal control group (P receptor showed no difference in all groups at two different temperatures (P > 0.05). The expression of P2X5 receptor was different in different syndrome groups at various ambient temperatures. Ambient temperatures had insignificant effect on the expression of P2X5 receptor of the population with the same syndrome.

  17. Facile palladium catalyzed Suzuki-Miyaura coupling in air and water at ambient temperature

    KAUST Repository

    Marziale, Alexander N.

    2010-01-01

    A new palladacyclic catalyst yields high activities in aqueous Suzuki-Miyaura coupling at room temperature. Using an optimized protocol, a broad range of products can be isolated in good to excellent yields and high purity by simple filtration. © 2010 The Royal Society of Chemistry.

  18. Evolution of the cyclic plastic response of Sanicro 25 steel cycled at ambient and elevated temperatures

    Czech Academy of Sciences Publication Activity Database

    Polák, Jaroslav; Petráš, Roman; Heczko, Milan; Kruml, Tomáš; Chai, G.

    2016-01-01

    Roč. 83, FEB (2016), s. 75-83 ISSN 0142-1123 R&D Projects: GA ČR(CZ) GA13-23652S Institutional support: RVO:68081723 Keywords : Cyclic plasticity * Hysteresis loop analysis * Heat resistant steel * Dislocation structure * Effect of temperature Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.899, year: 2016

  19. Ambient temperature impacts on pH of exhaled breath condensate.

    Science.gov (United States)

    Koczulla, Andreas R; Noeske, Sarah; Herr, Christian; Dette, Frank; Pinkenburg, Olaf; Schmid, Severin; Jörres, Rudolf A; Vogelmeier, Claus; Bals, Robert

    2010-01-01

    Analysis of exhaled breath condensate (EBC) pH is a non-invasive method to study airway inflammation. Low pH is correlated with inflammatory diseases like asthma and COPD. The aim of this study was to assess the influence of measurement temperature on pH values of EBC. EBC was collected using the RTube in 10 healthy non-smoking controls, 10 smokers before and after cigarette smoking, 10 stable COPD patients and 10 patients with exacerbated COPD. pH was determined directly after degassing at temperatures of 23 degrees C and 37 degrees C. When comparing all groups pH was significantly (P = 0.0002) higher (mean +/- SD 7.88 +/- 0.92) at 37 degrees C as compared with 23 degrees C (7.44 +/- 0.90). Specifically, at 23 degrees C pH was significantly lower in the group of exacerbated COPD (6.78 +/- 1.27) and healthy non-smoking controls (8.04 +/- 0.39). In contrast, subgroup analysis of values assessed at 37 degrees C did not display significant differences. Our data indicate a considerable influence of temperature on pH values in EBC. Thus the temperature at which pH measurements in EBC studies are performed should be declared.

  20. All-solid-state lithium-oxygen battery with high safety in wide ambient temperature range.

    Science.gov (United States)

    Kitaura, Hirokazu; Zhou, Haoshen

    2015-08-21

    There is need to develop high energy storage devices with high safety to satisfy the growing industrial demands. Here, we show the potential to realize such batteries by assembling a lithium-oxygen cell using an inorganic solid electrolyte without any flammable liquid or polymer materials. The lithium-oxygen battery using Li1.575Al0.5Ge1.5(PO4)3 solid electrolyte was examined in the pure oxygen atmosphere from room temperature to 120 °C. The cell works at room temperature and first full discharge capacity of 1420 mAh g(-1) at 10 mA g(-1) (based on the mass of carbon material in the air electrode) was obtained. The charge curve started from 3.0 V, and that the majority of it lay below 4.2 V. The cell also safely works at high temperature over 80 °C with the improved battery performance. Furthermore, fundamental data of the electrochemical performance, such as cyclic voltammogram, cycle performance and rate performance was obtained and this work demonstrated the potential of the all-solid-state lithium-oxygen battery for wide temperature application as a first step.

  1. Individual variation in metabolic reaction norms over ambient temperature causes low correlation between basal and standard metabolic rate.

    Science.gov (United States)

    Briga, Michael; Verhulst, Simon

    2017-09-15

    Basal metabolic rate (BMR) is often assumed to be indicative of the energy turnover at ambient temperatures ( T a ) below the thermoneutral zone (SMR), but this assumption has remained largely untested. Using a new statistical approach, we quantified the consistency in nocturnal metabolic rate across a temperature range in zebra finches ( N =3213 measurements on 407 individuals) living permanently in eight outdoor aviaries. Foraging conditions were either benign or harsh, and body mass and mass-adjusted BMR (BMR m ) and SMR (SMR m ) were lower in individuals living in a harsh foraging environment. The correlation between SMR m at different T a was high ( r =0.91), independent of foraging environment, showing that individuals are consistently ranked according to their SMR m However, the correlations between BMR m and SMR m were always lower (average: r =0.29; range: 0metabolic response to lower T a at least in part reflected differential body temperature ( T b ) regulation: early morning T b was lower at low T a , and more so in individuals with a weaker metabolic response to lower T a Our findings have implications for the use of BMR in the estimation of time-energy budgets and comparative analyses: we suggest that the use of metabolic rates at ecologically relevant T a , such as the easily tractable SMR, will be more informative than the use of BMR as a proxy for energy turnover. © 2017. Published by The Company of Biologists Ltd.

  2. Comparison of waste heat driven and electrically driven cooling systems for a high ambient temperature, off-grid application

    Science.gov (United States)

    Horvath, Christopher P.

    Forward army bases in off-grid locations with high temperatures require power and cooling capacity. Each gallon of fuel providing electrical power passes through a complex network, introducing issues of safety and reliability if this network is interrupted. Instead of using an engine and an electrically powered cooling system, a more efficient combined heat and power (CHP) configuration with a smaller engine and LiBr/Water absorption system (AS) powered by waste heat could be used. These two configurations were simulated in both steady state and transient conditions, in ambient temperatures up to 52°C, providing up to 3 kW of non-cooling electricity, and 5.3 kW of cooling. Unlike conventional AS's which crystallize at high temperatures and use bulky cooling towers, the proposed AS's avoid crystallization and have air-cooled HXs for portability. For the hottest transient week, the results showed fuel savings of 34-37%, weight reduction of 11-19%, and a volumetric footprint 3-10% smaller.

  3. Ambient high temperature and mortality in Jinan, China: A study of heat thresholds and vulnerable populations.

    Science.gov (United States)

    Li, Jing; Xu, Xin; Yang, Jun; Liu, Zhidong; Xu, Lei; Gao, Jinghong; Liu, Xiaobo; Wu, Haixia; Wang, Jun; Yu, Jieqiong; Jiang, Baofa; Liu, Qiyong

    2017-07-01

    Understanding the health consequences of continuously rising temperatures-as is projected for China-is important in terms of developing heat-health adaptation and intervention programs. This study aimed to examine the association between mortality and daily maximum (T max ), mean (T mean ), and minimum (T min ) temperatures in warmer months; to explore threshold temperatures; and to identify optimal heat indicators and vulnerable populations. Daily data on temperature and mortality were obtained for the period 2007-2013. Heat thresholds for condition-specific mortality were estimated using an observed/expected analysis. We used a generalised additive model with a quasi-Poisson distribution to examine the association between mortality and T max /T min /T mean values higher than the threshold values, after adjustment for covariates. T max /T mean /T min thresholds were 32/28/24°C for non-accidental deaths; 32/28/24°C for cardiovascular deaths; 35/31/26°C for respiratory deaths; and 34/31/28°C for diabetes-related deaths. For each 1°C increase in T max /T mean /T min above the threshold, the mortality risk of non-accidental-, cardiovascular-, respiratory, and diabetes-related death increased by 2.8/5.3/4.8%, 4.1/7.2/6.6%, 6.6/25.3/14.7%, and 13.3/30.5/47.6%, respectively. Thresholds for mortality differed according to health condition when stratified by sex, age, and education level. For non-accidental deaths, effects were significant in individuals aged ≥65 years (relative risk=1.038, 95% confidence interval: 1.026-1.050), but not for those ≤64 years. For most outcomes, women and people ≥65 years were more vulnerable. High temperature significantly increases the risk of mortality in the population of Jinan, China. Climate change with rising temperatures may bring about the situation worse. Public health programs should be improved and implemented to prevent and reduce health risks during hot days, especially for the identified vulnerable groups. Copyright

  4. Safety characteristics of hydrogen at super ambient conditions: lubricant contamination influencing the auto ignition temperature

    International Nuclear Information System (INIS)

    Liebner, C.; Schroder, V.; Holtappels, K.

    2006-01-01

    Inventing hydrogen as a commonly used future energy carrier the long term social acceptance as well as the clean energy image strongly depends upon the safety of its applications. The safety characteristics of hydrogen build a special challenge e.g. in the field of combustion engine development. Small impurities from lubricants used in motors and pumps, may serve as radical source, strongly influencing the auto ignition temperature of hydrogen. Auto Ignition Temperature (AIT) of Hydrogen-Air mixtures were measured in closed autoclaves made from stainless steel, similar to the closed bomb method described in the European standard EN 1839. Initial pressures of 10 bar(a) and 30 bar(a) of a premixed stoichiometric hydrogen-air mixture were investigated. Auto ignition can be obtained about 100 K below the standard AIT (560 deg C, atmospheric pressure) and 300 K below the standard AIT when contaminated through motor oil. (authors)

  5. Ambient-temperature superconductor symetrical metal-dihalide bis-(ethylenedithio)-tetrathiafulvalene compounds

    Science.gov (United States)

    Williams, Jack M.; Wang, Hsien-Hau; Beno, Mark A.

    1987-01-01

    A new class of organic superconductors having the formula (ET).sub.2 MX.sub.2 wherein ET represents bis(ethylenedithio)-tetrathiafulvalene, M is a metal such as Au, Ag, In, Tl, Rb, Pd and the like and X is a halide. The superconductor (ET).sub.2 AuI.sub.2 exhibits a transition temperature of 5 K. which is high for organic superconductors.

  6. Characterisation of iron oxide nanoparticles by Mössbauer spectroscopy at ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Joos, Alexander; Rümenapp, Christine [Zentralinstitut für Medizintechnik (IMETUM), Technische Universität München, Boltzmannstraße 11, 85748 Garching (Germany); Wagner, Friedrich E. [Physik-Department E15, Technische Universität München, James-Franck-Straße 1, 85748 Garching (Germany); Gleich, Bernhard, E-mail: gleich@tum.de [Zentralinstitut für Medizintechnik (IMETUM), Technische Universität München, Boltzmannstraße 11, 85748 Garching (Germany)

    2016-02-01

    Magnetite (Fe{sub 3}O{sub 4}) nanoparticles are important as contrast agents in magnetic resonance imaging or for magnetic drug targeting. Such particles can be made by different ways of synthesis, but depending on their size they tend to oxidise to maghemite (γ-Fe{sub 2}O{sub 3}), which is often less desirable because of its lower magnetisation. Mössbauer spectroscopy is well suited for determining the relative amounts of the two iron oxides in a sample. When measured at 4.2 K the nanoparticles typically exhibit well-defined but complicated hyperfine spectra that may present some problems of evaluation, but eventually yield reliable results for the degree of oxdation. At room temperature, however, particles smaller than about 15 nm are affected by superparamagnetic relaxation, which renders Mössbauer spectroscopy useless for their characterisation. To characterise magnetic nanoparticles even at room temperature, we designed an arrangement of permanent magnets to apply an external magnetic field of about 0.7 T to the Mössbauer absorbers. This has been found to be sufficient to give rise to magnetically split Mössbauer spectra that allow a distinction between magnetite and maghemite and to determine their relative amounts in a sample. - Highlights: • Mössbauer spectroscopy can be used to characterise magnetic nanoparticles (MNP). • Interpretation of room temperature spectra of MNP smaller than 15 nm is impossible. • We built a permanent magnet construction to apply a homogeneous field of 725 mT. • This field is enough to generate useful spectra of the MNP even at room temperature. • The magnetite content of small MNP can thus be determined.

  7. Potential energy savings using dynamically optimizing control in refrigeration systems under daily variations in ambient temperature

    DEFF Research Database (Denmark)

    Larsen, Lars Finn Sloth; Thybo, Claus; Wisniewski, Rafal

    2007-01-01

    The objective of this study is to investigate the energy saving potential for refrigeration systems by refrigeration more at the colder night time than at the warmer day time. The potential is evaluated using an optimal control policy and illustrated on a simulation example. The results show...... that the significant potential savings depends on two system parameters and the variation of the outdoor temperature. The system dependency is illustrated in a parameter study....

  8. Observation of immobile regions in natural rubber at ambient temperature by solid-state C-13 CP/MAS NMR spectroscopy

    DEFF Research Database (Denmark)

    Larsen, F.H.; Rasmussen, T.; Pedersen, Walther Batsberg

    1999-01-01

    Employing C-13 CP/MAS NMR spectroscopy, the existence of immobile regions in natural rubber (cis-1,4-polyisoprene) corresponding to a few percent of the monomer units has been detected at ambient temperature. For synthetic rubbers no immobile regions have been detected at all. Applying different ...... physical and chemical treatments to natural rubber it is shown that mastication, gamma-irradiation, and increasing the temperature, slightly above the ambient, reduce the amount of immobile regions. (C) 1999 Elsevier Science Ltd. All rights reserved....

  9. Environmental and Physiological Factors Associated With Stamina in Dogs Exercising in High Ambient Temperatures

    Directory of Open Access Journals (Sweden)

    Patrick J. Robbins

    2017-09-01

    Full Text Available This IACUC approved study was performed to evaluate the environmental, physiological, and hematological components that contribute to stamina following successive bouts of exercise that included searching (5-min, agility (5-min, and ball retrieve (<10-min. Regularly exercised dogs (N = 12 were evaluated on five separate occasions. The population consisted of eight males and four females ranging in age from 8 to 23 months, which included six Labrador retrievers, three German shepherds, and one each English springer spaniel, German wirehaired pointer, and Dutch shepherd. The exercise period was up to 30 min with 5 min of intermittent rest between the exercise bouts or until a designated trainer determined that the dog appeared fatigued (e.g., curled tongue while panting, seeking shade, or voluntary reluctance to retrieve. At the end of the exercise period, pulse rate (PR, core temperature, blood lactate, and venous blood gas were collected. The median outdoor temperature was 28.9°C (84°F (IQR; 27.2–30°C/81–86°F and median humidity was 47% (IQR; 40–57%. Median duration of exercise was 27 min (IQR; 25–29. No dog showed signs of heat stress that required medical intervention. The components used to measure stamina in this study were total activity, post-exercise core body temperature (CBT, and increase in CBT. When controlling for breed, total activity, as measured by omnidirectional accelerometer device, could be predicted from a linear combination of the independent variables: pre-exercise activity (p = 0.008, post-exercise activity (p < 0.001, outdoor temperature (p = 0.005, reduction in base excess in extracellular fluid compartment (BEecf (p = 0.044, and decrease in TCO2 (p = 0.005. When controlling for breed and sex, increase in CBT could be predicted from a linear combination of the independent variables: study day (p = 0.005, increase in PR (p < 0.001, increase in lactate (p = 0

  10. Environmental and Physiological Factors Associated With Stamina in Dogs Exercising in High Ambient Temperatures.

    Science.gov (United States)

    Robbins, Patrick J; Ramos, Meghan T; Zanghi, Brian M; Otto, Cynthia M

    2017-01-01

    This IACUC approved study was performed to evaluate the environmental, physiological, and hematological components that contribute to stamina following successive bouts of exercise that included searching (5-min), agility (5-min), and ball retrieve (dogs ( N  = 12) were evaluated on five separate occasions. The population consisted of eight males and four females ranging in age from 8 to 23 months, which included six Labrador retrievers, three German shepherds, and one each English springer spaniel, German wirehaired pointer, and Dutch shepherd. The exercise period was up to 30 min with 5 min of intermittent rest between the exercise bouts or until a designated trainer determined that the dog appeared fatigued (e.g., curled tongue while panting, seeking shade, or voluntary reluctance to retrieve). At the end of the exercise period, pulse rate (PR), core temperature, blood lactate, and venous blood gas were collected. The median outdoor temperature was 28.9°C (84°F) (IQR; 27.2-30°C/81-86°F) and median humidity was 47% (IQR; 40-57%). Median duration of exercise was 27 min (IQR; 25-29). No dog showed signs of heat stress that required medical intervention. The components used to measure stamina in this study were total activity, post-exercise core body temperature (CBT), and increase in CBT. When controlling for breed, total activity, as measured by omnidirectional accelerometer device, could be predicted from a linear combination of the independent variables: pre-exercise activity ( p  = 0.008), post-exercise activity ( p  < 0.001), outdoor temperature ( p  = 0.005), reduction in base excess in extracellular fluid compartment (BEecf) ( p  = 0.044), and decrease in TCO 2 ( p  = 0.005). When controlling for breed and sex, increase in CBT could be predicted from a linear combination of the independent variables: study day ( p  = 0.005), increase in PR ( p  < 0.001), increase in lactate ( p  = 0.001), reduction in BEecf ( p

  11. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    Science.gov (United States)

    Ortega, Amber M.; Hayes, Patrick L.; Peng, Zhe; Palm, Brett B.; Hu, Weiwei; Day, Douglas A.; Li, Rui; Cubison, Michael J.; Brune, William H.; Graus, Martin; Warneke, Carsten; Gilman, Jessica B.; Kuster, William C.; de Gouw, Joost; Gutiérrez-Montes, Cándido; Jimenez, Jose L.

    2016-06-01

    Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA) that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR) was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex) campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS) and a scanning mobility particle sizer (SMPS) alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days-6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA) from aging showed a maximum net SOA production between 0.8-6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH ˜ 0.3 day) SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs) in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope ˜ -0.65). Oxidation state of carbon (OSc) in reactor SOA increased steeply with age and remained elevated (OSC ˜ 2) at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background) vs. photochemical age is similar to previous studies at low to moderate ages and also extends to

  12. Real-time measurements of secondary organic aerosol formation and aging from ambient air in an oxidation flow reactor in the Los Angeles area

    Directory of Open Access Journals (Sweden)

    A. M. Ortega

    2016-06-01

    Full Text Available Field studies in polluted areas over the last decade have observed large formation of secondary organic aerosol (SOA that is often poorly captured by models. The study of SOA formation using ambient data is often confounded by the effects of advection, vertical mixing, emissions, and variable degrees of photochemical aging. An oxidation flow reactor (OFR was deployed to study SOA formation in real-time during the California Research at the Nexus of Air Quality and Climate Change (CalNex campaign in Pasadena, CA, in 2010. A high-resolution aerosol mass spectrometer (AMS and a scanning mobility particle sizer (SMPS alternated sampling ambient and reactor-aged air. The reactor produced OH concentrations up to 4 orders of magnitude higher than in ambient air. OH radical concentration was continuously stepped, achieving equivalent atmospheric aging of 0.8 days–6.4 weeks in 3 min of processing every 2 h. Enhancement of organic aerosol (OA from aging showed a maximum net SOA production between 0.8–6 days of aging with net OA mass loss beyond 2 weeks. Reactor SOA mass peaked at night, in the absence of ambient photochemistry and correlated with trimethylbenzene concentrations. Reactor SOA formation was inversely correlated with ambient SOA and Ox, which along with the short-lived volatile organic compound correlation, indicates the importance of very reactive (τOH  ∼  0.3 day SOA precursors (most likely semivolatile and intermediate volatility species, S/IVOCs in the Greater Los Angeles Area. Evolution of the elemental composition in the reactor was similar to trends observed in the atmosphere (O : C vs. H : C slope  ∼  −0.65. Oxidation state of carbon (OSc in reactor SOA increased steeply with age and remained elevated (OSC  ∼  2 at the highest photochemical ages probed. The ratio of OA in the reactor output to excess CO (ΔCO, ambient CO above regional background vs. photochemical age is similar to

  13. Passive control of temperature excursion and uniformity in high-energy Li-ion battery packs at high current and ambient temperature

    Energy Technology Data Exchange (ETDEWEB)

    Kizilel, R.; Lateef, A.; Sabbah, R.; Selman, J.R.; Al-Hallaj, S. [Center for Electrochemical Science and Engineering, Department of Chemical and Biological Engineering, Illinois Institute of Technology, Chicago, IL 60616 (United States); Farid, M.M. [Department of Chemical and Materials Engineering, Private Bag 92019, University of Auckland, Auckland (New Zealand)

    2008-08-15

    A strategy for portable high-power applications with a controlled thermal environment has been developed and has demonstrated the advantage of using the novel phase change material (PCM) thermal management systems over conventional active cooling systems. A passive thermal management system using PCM for Li-ion batteries is tested for extreme conditions, such as ambient temperature of 45 C and discharge rate of 2.08C-rate (10 A). Contrary to Li-ion packs without thermal management system, high-energy packs with PCM are discharged safely at high currents and degrading rate of capacity of the Li-ion packs lowered by half. Moreover, the compactness of the packs not only decreases the volume occupied by the packs and its associated complex cooling system, but also decreases the total weight for large power application. (author)

  14. The Effect of Ambient Temperature and Exercise to the Level of Exhaustion on

    Directory of Open Access Journals (Sweden)

    Somaye Kasharafifard

    2014-06-01

    Full Text Available Background: The increase in the amount of heat shock protein and C-reactive protein occurring as a result of stress was done with the aims of returning cell homeostasis, successful restoration of cell injury and protection of cell against more injuries. Materials and Methods: Fifteen climber and 15 non athlete subjects were chosen. A selected aerobic test was done by the subjects using Monark bicycle under two different conditions. Before starting the test, the subjects were exposed to a normal condition with the temperature of 24±2°C for an hour and a blood sample was taken from all the subjects. Then immediately, the subjects took the selected aerobic test to the level of exhaustion and blood sample was taken again. A week later, these subjects were exposed to a heated environment with the temperature of 38±2°C, followed by blood sample taking. Finally, the test was done by the subjects to the level of exhaustion and the last blood sample was taken. Then, the amount of heat shock protein (HSP and C - reactive protein (CRP in blood samples was measured. Results: A meaningful difference was observed in the changes of heat shock proteins (p=0.012 and C-reactive protein (p=0.02 between athlete and non athlete subjects. There was no meaningful difference in CRP and HSP in normal and hot condition for non athlete subjects before and after the test. But the result of the study demonstrates that There was a meaningful difference for athletes in both conditions before and after the test (p=0.002. Conclusion: Based on the study, it is claimed that while an athlete is exposed to several stressful conditions (e.g. high temperature and physical exercise, compared to a non athlete, the reaction of his body cells is more significant in order to prevent the injury.

  15. Research Update: Direct conversion of amorphous carbon into diamond at ambient pressures and temperatures in air

    International Nuclear Information System (INIS)

    Narayan, Jagdish; Bhaumik, Anagh

    2015-01-01

    We report on fundamental discovery of conversion of amorphous carbon into diamond by irradiating amorphous carbon films with nanosecond lasers at room-temperature in air at atmospheric pressure. We can create diamond in the form of nanodiamond (size range <100 nm) and microdiamond (>100 nm). Nanosecond laser pulses are used to melt amorphous diamondlike carbon and create a highly undercooled state, from which various forms of diamond can be formed upon cooling. The quenching from the super undercooled state results in nucleation of nanodiamond. It is found that microdiamonds grow out of highly undercooled state of carbon, with nanodiamond acting as seed crystals

  16. Effect of Surrogate Aggregates on the Thermal Conductivity of Concrete at Ambient and Elevated Temperatures

    Directory of Open Access Journals (Sweden)

    Tae Sup Yun

    2014-01-01

    Full Text Available The accurate assessment of the thermal conductivity of concretes is an important part of building design in terms of thermal efficiency and thermal performance of materials at various temperatures. We present an experimental assessment of the thermal conductivity of five thermally insulated concrete specimens made using lightweight aggregates and glass bubbles in place of normal aggregates. Four different measurement methods are used to assess the reliability of the thermal data and to evaluate the effects of the various sensor types. The concrete specimens are also assessed at every 100°C during heating to ~800°C. Normal concrete is shown to have a thermal conductivity of ~2.25 W m−1 K−1. The surrogate aggregates effectively reduce the conductivity to ~1.25 W m−1 K−1 at room temperature. The aggregate size is shown not to affect thermal conduction: fine and coarse aggregates each lead to similar results. Surface contact methods of assessment tend to underestimate thermal conductivity, presumably owing to high thermal resistance between the transducers and the specimens. Thermogravimetric analysis shows that the stages of mass loss of the cement paste correspond to the evolution of thermal conductivity upon heating.

  17. Influence of Ti in the β-Zr(Fe) phase stability at ambient temperature

    International Nuclear Information System (INIS)

    Coelho, J.S.

    1980-12-01

    Investigations of the Fe-Ti-Zr alloy system with concentrations ranging from 1 at.% Ti to 20 at.% Ti and with a fixed concentration of 4 at.% Fe were performed using X-Ray diffraction, Mossbauer Spectroscopy and Optical and Electronic Metallographies. The alloys were melted in arc furnace in argon atmosphere and after being homogenized, they were quenched from the beta field into cold water in order to retain the high temperature β-Zr(Fe)-Ti phase. The obtained results show that the beta phase was partially retained until the concentration of 7 at.% Ti and was completely retained at the concentration equal to or higher than 8 at.% Ti. It is assumed in Moessbauer Spectroscopy a doublet for the beta phase and a singlet for the supersatured α'-Zr(Fe)-Ti phase resulting from the martensitic transformation. The relative amount of each phase detected by Moessbauer Spectroscopy was measured by the relative area of the each spectral line. The stability of the beta phase at room temperature was discussed in terms of short-range ordering caused by the Fe-Ti bonds. Some related properties were discussed through the changing of the lattice parameter, isomer shift and quadrupole splitting. (Author) [pt

  18. Geomechanical behaviour of boom clay under ambient and elevated temperature conditions

    International Nuclear Information System (INIS)

    Neerdael, B.; Beaufays, R.; Buyens, M.; Bruyn, D. de; Voet, M.

    1992-01-01

    This research is focused upon in-situ investigations related to the (thermo-) mechanical behaviour of clay. Three main items are covered in this research area: Stress measurements around the underground research facility for radioactive waste disposal using hydraulical stress monitoring stations; detection of micro-fractures in the clay host, mainly using geophysical seismic techniques; long term mechanical behaviour of clay (this last item, studied by ANDRA at Mol, is not described in this paper). The stress monitoring stations appear to be more reliable in getting relative pressure variations with time rather than absolute values of stress, even after studying and improving the characteristics of the surrounding grout. The seismic techniques used to appear to be sensitive and accurate enough for detecting induced fracturation in the clay host, even for the low temperature. This is also in agreement with bench-scale experiments on clay samples intended to quantify the influence of both temperature and consolidation on the velocity. 10 refs., 80 figs., 3 tabs

  19. Long-term prediction of fish growth under varying ambient temperature using a multiscale dynamic model

    Directory of Open Access Journals (Sweden)

    Radde Nicole

    2009-11-01

    Full Text Available Abstract Background Feed composition has a large impact on the growth of animals, particularly marine fish. We have developed a quantitative dynamic model that can predict the growth and body composition of marine fish for a given feed composition over a timespan of several months. The model takes into consideration the effects of environmental factors, particularly temperature, on growth, and it incorporates detailed kinetics describing the main metabolic processes (protein, lipid, and central metabolism known to play major roles in growth and body composition. Results For validation, we compared our model's predictions with the results of several experimental studies. We showed that the model gives reliable predictions of growth, nutrient utilization (including amino acid retention, and body composition over a timespan of several months, longer than most of the previously developed predictive models. Conclusion We demonstrate that, despite the difficulties involved, multiscale models in biology can yield reasonable and useful results. The model predictions are reliable over several timescales and in the presence of strong temperature fluctuations, which are crucial factors for modeling marine organism growth. The model provides important improvements over existing models.

  20. Measurement of the thermal inertia of the skin using successive thermograms taken at a stepwise change in ambient radiation temperature.

    Science.gov (United States)

    Huang, J; Togawa, T

    1995-11-01

    Skin thermal properties are difficult to measure in vivo in the steady state because there is a constant temperature gradient across the skin surface. However, measurement of skin thermal properties is postulated in quantitative evaluation for thermographic observation. In this study, imaging of the thermal inertia of the skin was attempted by thermographic measurements at a stepwise change in ambient radiation temperature achieved by quickly switching two hoods maintained at different temperatures. Using this technique, a total of 65 thermograms were sequentially recorded at intervals of 0.5 s beginning 2 s before the stepwise change. The image of skin thermal inertia was estimated by applying statistical curve fitting at each pixel of the thermograms. In addition, the emissivity and true temperature of the skin were also determined, together with thermal inertia, in a single measurement. Measurements were made at different sites on 10 subjects. The average values of thermal inertia of normal skin were scattered throughout a range from 1.4 x 10(3) to 2.1 x 10(3) W s1/2 m-2 K-1. Investigations of the relationship between skin blood flow and thermal inertia were also made by imaging thermal inertia when skin blood flow was changed by applying a vasodilator or vasoconstrictor on the skin surface. In a comparison with the data measured by laser Doppler flowmetry, the average slope of skin blood flow versus thermal inertia was 2.88 x 10(-4) V per W s1/2 m-2 K-1, and the thermal inertia of the skin with no blood flow was 1.03 x 10(3) W s1/2 m-2 K-1. The results also show an almost linear correlation between skin blood flow and thermal inertia in each individual, but inter-individual differences were also observed. The results suggest that skin blood flow distribution can be estimated by non-contact imaging of thermal inertia.

  1. Evaluation of an Absorption Heat Pump to Mitigate Plant Capacity Reduction Due to Ambient Temperature Rise for an Air-Cooled Ammonia and Water Cycle: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Bharathan, D.; Nix, G.

    2001-08-06

    Air-cooled geothermal plants suffer substantial decreases in generating capacity at increased ambient temperatures. As the ambient temperature rises by 50 F above a design value of 50 F, at low brine-resource temperatures, the decrease in generating capacity can be more than 50%. This decrease is caused primarily by increased condenser pressure. Using mixed-working fluids has recently drawn considerable attention for use in power cycles. Such cycles are more readily amenable to use of absorption ''heat pumps.'' For a system that uses ammonia and water as the mixed-working fluid, this paper evaluates using an absorption heat pump to reduce condenser backpressure. At high ambient temperatures, part of the turbine exhaust vapor is absorbed into a circulating mixed stream in an absorber in series with the main condenser. This steam is pumped up to a higher pressure and heated to strip the excess vapor, which is recondensed using an additional air-cooled condenser. The operating conditions are chosen to reconstitute this condensate back to the same concentration as drawn from the original system. We analyzed two power plants of nominal 1-megawatt capacity. The design resource temperatures were 250 F and 300 F. Ambient temperature was allowed to rise from a design value of 50 F to 100 F. The analyses indicate that using an absorption heat pump is feasible. For the 300 F resource, an increased brine flow of 30% resulted in a net power increase of 21%. For the 250 F resource, the increase was smaller. However, these results are highly plant- and equipment-specific because evaluations must be carried out at off-design conditions for the condenser. Such studies should be carried out for specific power plants that suffer most from increased ambient temperatures.

  2. Role of wing color and seasonal changes in ambient temperature and solar irradiation on predicted flight efficiency of the Albatross.

    Science.gov (United States)

    Hassanalian, M; Throneberry, G; Ali, M; Ben Ayed, S; Abdelkefi, A

    2018-01-01

    Drag reduction of the wings of migrating birds is crucial to their flight efficiency. Wing color impacts absorption of solar irradiation which may affect drag but there is little known in this area. To this end, the drag reduction induced by the thermal effect of the wing color of migrating birds with unpowered flight modes is presented in this study. Considering this natural phenomenon in the albatross as an example of migrating birds, and applying an energy balance for this biological system, a thermal analysis is performed on the wings during the summer and winter to obtain different ranges of air density, viscosity, and wing surface temperature brought about from a range of ambient temperatures and climatic conditions seen in different seasons and to study their effects. The exact shape of the albatross wing is used and nine different wing colors are considered in order to gain a better understanding of the effect different colors' absorptivities make on the change in aerodynamic performances. The thermal effect is found to be more important during the summer than during the winter due to the higher values of solar irradiation and a maximum drag reduction of 7.8% is found in summer changing the wing color from light white to dark black. The obtained results show that albatrosses with darker colored wings are more efficient (constant lift to drag ratio and drag reduction) and have better endurance due to this drag reduction. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of season and high ambient temperature on activity levels and patterns of grizzly bears (Ursus arctos).

    Science.gov (United States)

    McLellan, Michelle L; McLellan, Bruce N

    2015-01-01

    Understanding factors that influence daily and annual activity patterns of a species provides insights to challenges facing individuals, particularly when climate shifts, and thus is important in conservation. Using GPS collars with dual-axis motion sensors that recorded the number of switches every 5 minutes we tested the hypotheses: 1. Grizzly bears (Ursus arctos) increase daily activity levels and active bout lengths when they forage on berries, the major high-energy food in this ecosystem, and 2. Grizzly bears become less active and more nocturnal when ambient temperature exceeds 20°C. We found support for hypothesis 1 with both male and female bears being active from 0.7 to 2.8 h longer in the berry season than in other seasons. Our prediction under hypothesis 2 was not supported. When bears foraged on berries on a dry, open mountainside, there was no relationship between daily maximum temperature (which varied from 20.4 to 40.1°C) and the total amount of time bears were active, and no difference in activity levels during day or night between warm (20.4-27.3°C) and hot (27.9-40.1°C) days. Our results highlight the strong influence that food acquisition has on activity levels and patterns of grizzly bears and is a challenge to the heat dissipation limitation theory.

  4. Effects of ambient air temperature, humidity and rainfall on annual survival of adult little penguins Eudyptula minor in southeastern Australia

    Science.gov (United States)

    Ganendran, L. B.; Sidhu, L. A.; Catchpole, E. A.; Chambers, L. E.; Dann, P.

    2016-08-01

    Seabirds are subject to the influences of local climate variables during periods of land-based activities such as breeding and, for some species, moult; particularly if they undergo a catastrophic moult (complete simultaneous moult) as do penguins. We investigated potential relationships between adult penguin survival and land-based climate variables (ambient air temperature, humidity and rainfall) using 46 years of mark-recapture data of little penguins Eudyptula minor gathered at a breeding colony on Phillip Island in southeastern Australia. Our results showed that adult penguin survival had a stronger association with land-based climate variables during the moult period, when birds were unable to go to sea for up to 3 weeks, than during the breeding period, when birds could sacrifice breeding success in favour of survival. Annual adult survival probability was positively associated with humidity during moult and negatively associated with rainfall during moult. Prolonged heat during breeding and moult had a negative association with annual adult survival. Local climate projections suggest increasing days of high temperatures, fewer days of rainfall which will result in more droughts (and by implication, lower humidity) and more extreme rainfall events. All of these predicted climate changes are expected to have a negative impact on adult penguin survival.

  5. The effects of day length, hibernation, and ambient temperature on incisor dentin in the Turkish hamster (Mesocricetus brandti).

    Science.gov (United States)

    Batavia, Mariska; Nguyen, George; Zucker, Irving

    2013-05-01

    Dentin is deposited on a circadian basis, and daily layers manifest as bands on the medial surfaces of rodent incisors. Hibernation alters dentin deposition, and a distinct hibernation mark has been described on incisor surfaces of several rodent species; the factors that influence the morphology of this mark are poorly understood. We tested the effects of day length, torpor expression, and ambient temperature on incisor surface morphology in Turkish hamsters housed in one of four conditions: long days (LDs) at 22 °C, short days (SDs) at 22 °C, SDs at 5 °C, and SDs at 13 °C. Body temperature was monitored continuously with implanted radio transmitters, and teeth examined postmortem. Teeth of SD hamsters had narrower, less distinct circadian increments than those of LD hamsters, but the width of ultradian increments was similar in both photoperiods. Hibernation at both 5 and 13 °C was associated in most specimens with very narrow, sharply defined dentin increments and increased tooth heterogeneity. Hamsters in SDs at 5 °C that did not hibernate lacked characteristic hibernation increments. At 5 °C, but not 13 °C, the number and cumulative width of hibernation increments were related to number and cumulative duration of periodic arousals. Our results suggest that incremental deposition of dentin in rodent incisors may be a useful trait for characterizing hibernation behavior in both evolutionary and historical contexts.

  6. Effects of ambient temperature and water vapor on chamber pressure and oxygen level during low atmospheric pressure stunning of poultry.

    Science.gov (United States)

    Holloway, Paul H; Pritchard, David G

    2017-08-01

    The characteristics of the vacuum used in a low atmospheric pressure stunning system to stun (render unconscious) poultry prior to slaughter are described. A vacuum chamber is pumped by a wet screw compressor. The vacuum pressure is reduced from ambient atmospheric pressure to an absolute vacuum pressure of ∼250 Torr (∼33 kPa) in ∼67 sec with the vacuum gate valve fully open. At ∼250 Torr, the sliding gate valve is partially closed to reduce effective pumping speed, resulting in a slower rate of decreasing pressure. Ambient temperature affects air density and water vapor pressure and thereby oxygen levels and the time at the minimum total pressure of ∼160 Torr (∼21 kPa) is varied from ∼120 to ∼220 sec to ensure an effective stun within the 280 seconds of each cycle. The reduction in total pressure results in a gradual reduction of oxygen partial pressure that was measured by a solid-state electrochemical oxygen sensor. The reduced oxygen pressure leads to hypoxia, which is recognized as a humane method of stunning poultry. The system maintains an oxygen concentration of controller and the human machine interface enable precise and accurate control. The vacuum system operates in the turbulent viscous flow regime, and is best characterized by absolute vacuum pressure rather than gauge pressure. Neither the presence of broiler chickens nor different fore-line pipe designs of four parallel commercial systems affected the pressure-time data. Water in wet air always reduces the oxygen concentrations to a value lower than in dry air. The partial pressure of water and oxygen were found to depend on the pump down parameters due to the formation of fog in the chamber and desorption of water from the birds and the walls of the vacuum chamber. © The Author 2017. Published by Oxford University Press on behalf of Poultry Science Association.

  7. Rod-Shaped Magnetite Nano/Microparticles Synthesis at Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Balaprasad Ankamwar

    2013-01-01

    Full Text Available Here, we reported room temperature synthesis of Fe3O4 rod-shaped nano/microparticles by chemical reduction method from FeCl3 precursor and NaBH4 as the reducing agent in the presence of the pyrrole as a capping agent. The magnetic Fe3O4 particles were characterized by several methods, such as SEM, XRD, FTIR, and TGA. The average aspect ratio of Fe3O4 rod-shaped particles was ~2.8. These particles were redispersed in deionised water to form a colloidal solution and showed magnetic properties. This economical synthesis route is scalable, and Fe3O4 particles can be exploited for various applications such as MRI contrast enhancement, biodiseperations, Ni-Fe batteries, and as a catalyst.

  8. Non-Contacting Finger Seals Static Performance Test Results at Ambient and High Temperatures

    Science.gov (United States)

    Proctor, Margaret P.

    2016-01-01

    The non-contacting finger seal is an advanced seal concept with potential to reduce specific fuel consumption in gas turbine engines by 2 to 3 with little to no wear of the seal or rotor. Static performance tests and bind-up tests of eight different non-contacting finger seal configurations were conducted in air at pressure differentials up to 689.4 kPa and temperatures up to 922 K. Four of the seals tested were designed to have lift pads concentric to a herringbone-grooved rotor which generates hydrodynamic lift when rotating. The remaining seals were tested with a smooth rotor; one seal had a circumferential taper and one had an axial taper on the lift pad inner diameter to create hydrodynamic lift during rotation. The effects of the aft finger axial thickness and of the forward finger inner diameter on leakage performance were investigated as well and compared to analytical predictions.

  9. INFLUENCE OF TEMPERATURE ON THE CORROSION POTENTIAL OF THE 241-AN-102 MULTI PROBE CORROSION MONITORING SYSTEM SECONDARY REFERENCE ELECTRODES

    Energy Technology Data Exchange (ETDEWEB)

    EDGEMON GL; TAYLOR TM

    2008-09-30

    A test program using 241-AN-102 waste simulants and metallic secondary reference electrodes similar to those used on the 241-AN-102 MPCMS was performed to characterize the relationship between temperature and secondary reference electrode open-circuit corrosion potential. This program showed that the secondary reference electrodes can be used to make tank and tank steel corrosion potential measurements, but that a correction factor of approximately 2 mV per degree Celsius of temperature difference must be applied, where temperature difference is defined as the difference between tank temperature at the time of measurement and 30 C, the average tank temperature during the first several months of 241-AN-102 MPCMS operation (when the corrosion potentials of the secondary reference electrodes were being recorded relative to the primary reference electrodes).

  10. Variability of the breathing pattern in newborn rats: effects of ambient temperature in normoxia or hypoxia.

    Science.gov (United States)

    Cameron, Y L; Merazzi, D; Mortola, J P

    2000-06-01

    We hypothesized that the inter-breath variability of the breathing pattern in newborn rats varied with temperature and oxygenation. Breathing pattern was recorded in 4-day-old rats by airflow plethysmography, during normoxia in warm (control) and cold conditions, or during hypoxia (inspired O2 = 10%) in warm or cold conditions, each lasting 15 min. The warm phase (36 degrees C) either preceded or followed the cold (24 degrees C). Time-domain analysis was applied to 500 continuous breaths recorded toward the end of each phase. All parameters describing the breathing pattern (instantaneous ventilation, tidal volume, and inspiratory and expiratory time) had lower variability when the condition differed from control i.e. in cold or hypoxia, with no correlation with the absolute level of ventilation. The difference in variability between warm-normoxia and the other conditions was reduced when cold preceded the warm phase. Gaseous metabolism was increased in cold because of thermogenesis. When the cold preceded the warm phase the increased thermogenesis partly persisted into the warm phase, raising the metabolic level. We conclude that the variability of the breathing pattern in newborn rats 1) does not depend on the absolute level of ventilation, and 2) is reduced by the increased chemical stimuli occurring during cold-hypermetabolism or hypoxia. In normoxia in warm condition metabolic and chemical stimuli are low, and the variability is the highest. The results are in agreement with the clinical observations of a higher incidence of apneic episodes in infants during warm conditions.

  11. Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

    Science.gov (United States)

    Romero-Trigueros, Cristina; Doval Miñarro, Marta; González Duperón, Esther; González Ferradás, Enrique

    2017-10-01

    Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID) is studied. Two reference gas mixtures (40 and 5 µg m-3 nominal concentration benzene in air) were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C) and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C). When measuring a concentration of 0.5 µg m-3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m-3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m-3), biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm-3 - corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

  12. Treatment of strong domestic sewage in a 96 m3 UASB reactor operated at ambient temperatures: two-stage versus single-stage reactor

    NARCIS (Netherlands)

    Halalsheh, M.M.I.; Sawajneh, Z.; Zu'bi, M.; Zeeman, G.; Lier, van J.B.; Fayyad, M.; Lettinga, G.

    2005-01-01

    A 96 m(3) UASB reactor was operated for 2.5 years under different conditions to assess the feasibility of treating strong sewage (CODtot = 1531 mg/l) at ambient temperatures, with averages of 18 and 25 degreesC for winter and summer respectively. During the first year, the reactor was operated as a

  13. Development of rabbit embryos during a 96-h period of in vitro culture after superovulatory treatment under conditions of elevated ambient temperature.

    Science.gov (United States)

    Cheng, H; Dooley, M P; Hopkins, S M; Anderson, L L; Yibchok-anun, S; Hsu, W H

    1999-08-16

    The effects of elevated ambient temperature on the response to exogenous gonadotropins were evaluated in female New Zealand White rabbits exposed to 33+/-1 degrees C (mean +/- SE) and 10-30% relative humidity (8 h/day) during a 5-day period. Does were treated with pFSH (0.3 mg/0.3 ml Standard Armour) twice daily during three consecutive days with a minimum interval of 8 h between injections. Six hours after the last FSH injection all does were removed from the experimental chamber, given hCG (25 IU/kg) and paired overnight. Nineteen hours after pairing, embryos were flushed from the reproductive tracts, evaluated, and subjected to in vitro culture during a 96-h period. The ovulatory responses to exogenous gonadotropins and fertilization rates did not differ significantly under conditions of elevated ambient temperature, whereas fewer blastocysts and increased number of degenerate embryos were observed after culture. We conclude that although hyperthermia was induced during exposure to elevated ambient temperature, it did not alter the ovulatory responses to gonadotropin treatment and plasma concentrations of FSH and LH compared with does in a thermoneutral environment. Exposure of donor rabbits to elevated ambient temperature before mating, however, increased embryonic degeneration.

  14. Patients presenting with miliaria while wearing flame resistant clothing in high ambient temperatures: a case series

    Directory of Open Access Journals (Sweden)

    Garcia Anisa M

    2011-09-01

    Full Text Available Abstract Introduction Clothing can be a cause of occupational dermatitis. Frequent causes of clothing-related dermatological problems can be the fabric itself and/or chemical additives used in the laundering process, friction from certain fabrics excessively rubbing the skin, or heat retention from perspiration-soaked clothing in hot working environments. To the best of our knowledge, these are the first reported cases of miliaria rubra associated with prolonged use of flame resistant clothing in the medical literature. Case presentation We report 18 cases (14 men and 4 women, with an age range of 19 to 37 years of moderate to severe skin irritation associated with wearing flame resistant clothing in hot arid environments (temperature range: 39 to 50°C, 5% to 25% relative humidity. We describe the medical history in detail of a 23-year-old Caucasian woman and a 31-year-old African-American man. A summary of the other 16 patients is also provided. Conclusions These cases illustrate the potential serious nature of miliaria with superimposed Staphylococcus infections. All 18 patients fully recovered with topical skin treatment and modifications to their dress ensemble. Clothing, in particular blend fabrics, must be thoroughly laundered to adequately remove detergent residue. While in hot environments, individuals with sensitive skin should take the necessary precautions such as regular changing of clothing and good personal hygiene to ensure that their skin remains as dry and clean as possible. It is also important that they report to their health care provider as soon as skin irritation or rash appears to initiate any necessary medical procedures. Miliaria rubra can take a week or longer to clear, so removal of exposure to certain fabric types may be necessary.

  15. Hydration products of lime-metakaolin pastes at ambient temperature with ageing

    Energy Technology Data Exchange (ETDEWEB)

    Gameiro, A., E-mail: agameiro@lnec.pt [National Laboratory of Civil Engineering, Materials Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Santos Silva, A., E-mail: ssilva@lnec.pt [National Laboratory of Civil Engineering, Materials Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Veiga, R., E-mail: rveiga@lnec.pt [National Laboratory of Civil Engineering, Buildings Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Velosa, A., E-mail: avelosa@ua.pt [Department of Civil Engineering, Geobiotec, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)

    2012-05-10

    Highlights: Black-Right-Pointing-Pointer We study the compounds formed in lime/MK blended pastes and their stability over time. Black-Right-Pointing-Pointer Different mixes of lime/MK pastes show different reaction kinetics during curing time, being the pozzolanic compounds formed directly proportional to the lime by MK replacement. Black-Right-Pointing-Pointer Some pozzolanic products are found to be unstable during the hydration reaction employed in our study. - Abstract: Mortars constituted of lime mixtures with pozzolanic additions have been extensively used in the past for the construction of historic and traditional buildings. This paper presents the results of blended pastes of lime and metakaolin (MK), namely compounds formed and their stability over time. This research is part of an extensive study aiming at the formulation of lime based mortars for restoration purposes. It has been shown for several years that MK has been applied in inorganic binders due to its capacity to react vigorously with calcium hydroxide (CH). In the presence of water originating a series of major hydrated phases, namely tetra calcium aluminate hydrate (C{sub 4}AH{sub 13}), calcium silicates hydrates (CSH) and calcium aluminium silicate hydrates (stratlingite - C{sub 2}ASH{sub 8}). Several blended pastes of lime and MK, with different substitution rates of lime by MK (wt%) were prepared and cured at a temperature of 20 Degree-Sign C and relative humidity RH > 95%. The phase composition of the formed hydrated phases was determined by X-ray diffraction (XRD) and simultaneous thermal analysis (TG-DTA). The obtained results showed that lime/MK pastes compositions displayed different reaction kinetics during curing time, being the pozzolanic products content directly proportional to the substitution rate of lime by MK. Also, a relationship between the increase stratlingite content and the MK substitution rate of lime by MK was found.

  16. Degradation of the unbiodegradable particulate fraction (XU) from different activated sludges during batch digestion tests at ambient temperature.

    Science.gov (United States)

    Habermacher, Jonathan; Benetti, Antonio Domingues; Derlon, Nicolas; Morgenroth, Eberhard

    2016-07-01

    One strategy for the management of excess sludge in small wastewater treatment plants (WWTPs) consists in minimizing the excess sludge production by operating the WWTP at very long solids retention times (SRTs > 30 days). A number of recent studies have suggested that sludge minimization at very long SRT results from the degradation of the unbiodegradable particulate fraction (XU) (influent unbiodegradable compounds and endogenous decay products). But the biodegradability of the unbiodegradable particulate fraction has only been evaluated during batch digestion test performed at ambient temperature with sludge fed with synthetic wastewaters. It is not clear to what extent observations made for sludge fed with synthetic influents can be transposed to sludge fed with real influent. The current study thus focused on evaluating the biodegradability of the unbiodegradable particulate fraction for sludge fed with real wastewater. Batch digestion tests (400 days, ambient temperature) were conducted with three different sludges fed with either synthetic or real influents and exposed to aerobic or intermittent aeration conditions. Our results indicate that volatile suspended solids (VSS) decreased even after complete decay of the active biomass (i.e., after 30 days of aerobic batch digestion) indicating that the unbiodegradable particulate fraction is biodegradable. However, very low degradation rates of the unbiodegradable particulate fraction were monitored after day 30 of digestion (0.7-1.7·10(-3) d(-1)). These values were in the lower range of previously published values for synthetic wastewaters (1-7.5·10(-3) d(-1)). The low values determined in our study indicate that the rate could decrease over time or that sludge composition influences the degradability of the unbiodegradable particulate fraction. But our results also demonstrate that extracellular polymeric substances (EPS) have a minor impact on the biodegradability of the unbiodegradable particulate

  17. Effects of ambient temperature and oxygen concentration on diesel spray combustion using a single-nozzle injector in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei

    2013-09-02

    This work investigates the effects of ambient conditions on diesel spray combustion in an optically accessible, constant volume chamber using a single-nozzle fuel injector. The ambient O2 concentration was varied between five discrete values from 10% to 21% and three different ambient temperatures (800 K, 1000 K, and 1200 K). These conditions simulate different exhaust gas recirculation (EGR) levels and ambient temperatures in diesel engines. Both conventional diesel combustion and low temperature combustion (LTC) modes were observed under these conditions. A transient analysis and a quasi-steady state analysis are employed in this article. The transient analysis focuses on the flame development from beginning to the end, illustrating how the flame structure changes during this process; the quasi-steady state analysis focuses on the stable flame structure. The transient analysis was conducted using high-speed imaging of both OH* chemiluminescence and natural luminosity (NL). In addition, three different images were acquired using an ICCD camera, corresponding to OH* chemiluminescence, narrow-band flame emission at 430 nm (Band A) and at 470 nm (Band B), and were used to investigate the quasi-steady state combustion process. From the transient analysis, it was found that the NL signal becomes stronger and confined to narrow regions when the temperature and O2 concentration increase during the development of flame. The OH* intensity is much lower for the 10% ambient O2 and 800 K conditions compared to the higher temperatures and O2 levels. This implies the occurrence of LTC under these conditions. Results from the quasi-steady combustion stage indicate that high-temperature reactions effectively oxidize the soot in the downstream locations where only OH* signal is observed. In addition, an area was calculated for each spectral region, and results show that the area of Band A and Band B emissions in these images is larger than the area of OH* emissions at the lower O2

  18. The effect of ambient temperature and type of wound on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis).

    OpenAIRE

    Smith, D A; Barker, I K; Allen, O B

    1988-01-01

    The effects of ambient temperature (13.5 degrees C, 21 degrees C, 30 degrees C) and type of wound on healing of skin wounds were evaluated in common garter snakes (Thamnophis sirtalis). Linear unsutured incisions and circular excisional wounds were evaluated grossly and microscopically in three snakes held at each temperature at each of two, five and ten days after surgery. Linear sutured and unsutured incisions and circular and square excisional wounds were similarly evaluated three and six ...

  19. KCl-Induced High-Temperature Corrosion Behavior of HVAF-Sprayed Ni-Based Coatings in Ambient Air

    Science.gov (United States)

    Jafari, Reza; Sadeghimeresht, Esmaeil; Farahani, Taghi Shahrabi; Huhtakangas, Matti; Markocsan, Nicolaie; Joshi, Shrikant

    2018-02-01

    KCl-induced high-temperature corrosion behavior of four HVAF-sprayed Ni-based coatings (Ni21Cr, Ni5Al, Ni21Cr7Al1Y and Ni21Cr9Mo) under KCl deposit has been investigated in ambient air at 600 °C up to 168 h. The coatings were deposited onto 16Mo3 steel—a widely used boiler tube material. Uncoated substrate, 304L and Sanicro 25 were used as reference materials in the test environment. SEM/EDS and XRD techniques were utilized to characterize the as-sprayed and exposed samples. The results showed that the small addition of KCl significantly accelerated degradation to the coatings. All coatings provided better corrosion resistance compared to the reference materials. The alumina-forming Ni5Al coating under KCl deposit was capable of forming a more protective oxide scale compared to the chromia-forming coatings as penetration of Cl through diffusion paths was hindered. Both active corrosion and chromate formation mechanisms were found to be responsible for the corrosion damages. The corrosion resistance of the coatings based on the microstructure analysis and kinetics had the following ranking (from the best to worst): Ni5Al > Ni21Cr > Ni21Cr7Al1Y > Ni21Cr9Mo.

  20. In Situ Ambient Pressure X-ray Photoelectron Spectroscopy of Cobalt Perovskite Surfaces under Cathodic Polarization at High Temperatures

    KAUST Repository

    Crumlin, Ethan J.

    2013-08-08

    Heterostructured oxide interfaces have demonstrated enhanced oxygen reduction reaction rates at elevated temperatures (∼500-800 C); however, the physical origin underlying this enhancement is not well understood. By using synchrotron-based in situ ambient pressure X-ray photoelectron spectroscopy (APXPS), we focus on understanding the surface electronic structure, elemental composition, and chemical nature of epitaxial La0.8Sr 0.2CoO3-δ (LSC113), (La 0.5Sr0.5)2CoO4±δ (LSC214), and LSC214-decorated LSC113 (LSC 113/214) thin films as a function of applied electrical potentials (0 to -800 mV) at 520 C and p(O2) of 1 × 10-3 atm. Shifts in the top of the valence band binding energy and changes in the Sr 3d and O 1s spectral components under applied bias reveal key differences among the film chemistries, most notably in the degree of Sr segregation to the surface and quantity of active oxygen sites in the perovskite termination layer. These differences help to identify important factors governing the enhanced activity of oxygen electrocatalysis observed for the LSC113/214 heterostructured surface. © 2013 American Chemical Society.

  1. Excimer laser assisted very fast exfoliation and reduction of graphite oxide at room temperature under air ambient for Supercapacitors electrode

    Science.gov (United States)

    Malek Hosseini, S. M. B.; Baizaee, S. M.; Naderi, Hamid Reza; Dare Kordi, Ali

    2018-01-01

    Excimer laser was used for reduction and exfoliation of graphite oxide (GO) at room temperature under air ambient. The prepared excimer laser reduced graphite oxide (XLRGO) is characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), nitrogen adsorption/desorption (BET method), X-ray diffraction (XRD), X-ray photoemission spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and UV-vis absorption techniques for surface, structural functional groups and band gap analysis. Electrochemical properties are investigated using cyclic voltammetry, galvanostatic charge-discharge, electrochemical impedance spectroscopy (EIS) and continues cyclic voltammetry (CCV) in 0.5 M Na2SO4 as electrolyte. Electrochemical investigations revealed that XLRGO electrode has enhanced supercapacitive performance including specific capacitance of 299 F/g at a scan rate of 2 mV/s. Furthermore, CCV measurement showed that XLRGO electrode kept 97.8% of its initial capacitance/capacity after 4000 cycles. The obtained results from electrochemical investigations confirm that the reduction of GO by using an excimer laser produces high-quality graphene for supercapacitor applications without the need for additional operations.

  2. Impact of ambient air temperature and heat load variation on the performance of air-cooled heat exchangers in propane cycles in LNG plants – Analytical approach

    International Nuclear Information System (INIS)

    Fahmy, M.F.M.; Nabih, H.I.

    2016-01-01

    Highlights: • An analytical method regulated the air flow rate in an air-cooled heat exchanger. • Performance of an ACHE in a propane cycle in an LNG plant was evaluated. • Summer inlet air temperature had higher impact on ACHE air flow rate requirement. - Abstract: An analytical method is presented to evaluate the air flow rate required in an air-cooled heat exchanger used in a propane pre-cooling cycle operating in an LNG (liquefied natural gas) plant. With variable ambient air inlet temperature, the air flow rate is to be increased or decreased so as to assure and maintain good performance of the operating air-cooled heat exchanger at the designed parameters and specifications. This analytical approach accounts for the variations in both heat load and ambient air inlet temperature. The ambient air inlet temperature is modeled analytically by simplified periodic relations. Thus, a complete analytical method is described so as to manage the problem of determining and accordingly regulate, either manually or automatically, the flow rate of air across the finned tubes of the air-cooled heat exchanger and thus, controls the process fluid outlet temperature required for the air-cooled heat exchangers for both cases of constant and varying heat loads and ambient air inlet temperatures. Numerical results are obtained showing the performance of the air-cooled heat exchanger of a propane cycle which cools both NG (natural gas) and MR (mixed refrigerant) streams in the LNG plant located at Damietta, Egypt. The inlet air temperature variation in the summer time has a considerable effect on the required air mass flow rate, while its influence becomes relatively less pronounced in winter.

  3. Chemometric optimization of a low-temperature plasma source design for ambient desorption/ionization mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Albert, Anastasia [University of Muenster, Institute of Inorganic and Analytical Chemistry, Corrensstraße 30, 48149 Muenster (Germany); Engelhard, Carsten, E-mail: engelhard@chemie.uni-siegen.de [University of Siegen, Department of Chemistry and Biology, Adolf-Reichwein-Straße 2, 57076 Siegen (Germany)

    2015-03-01

    Low-temperature plasmas (LTPs) are attractive sources for atomic and molecular mass spectrometry (MS). In the past, the LTP probe, which was first described by Harper et al., was used successfully for direct molecular mass spectrometric analysis with minimal sample pretreatment in a variety of applications. Unfortunately, the desorption/ionization source itself is commercially not available and custom-built LTP set-ups with varying geometry and operational configurations were utilized in the past. In the present study, a rapid chemometrics approach based on systematic experiments and multivariate data analysis was used to optimize the LTP probe geometry and positioning relative to the atmospheric-pressure inlet of a mass spectrometer. Several parameters were studied including the probe geometry, electrode configuration, quartz tube dimensions, probe positioning and operating conditions. It was found that the plasma-to-MS-inlet distance, the plasma-to-sample-plate distance, and the angle between the latter are very important. Additional effects on the analytical performance were found for the outer electrode width, the positioning of the electrodes, the inner diameter of the quartz tube, the quartz wall thickness, and the gas flow. All experiments were performed using additional heating of the sample to enhance thermal desorption and maximize the signal (T = 150 °C). After software-assisted optimization, attractive detection limits were achieved (e.g., 1.8 × 10{sup −7} mol/L for 4-acetamidothiophenol). Moreover, relative standard deviation (RSD) improved from values of up to 30% before optimization to < 15% RSD after the procedure was completed. This chemometrics approach for method optimization is not limited to LTP-MS and considered to be attractive for other plasma-based instrumentation as well. - Highlights: • Plasmas are useful in ambient desorption/ionization mass spectrometry. • Rapid and direct analysis is performed without sample preparation.

  4. Physiological Effects of Ergot Alkaloid and Indole-Diterpene Consumption on Sheep under Hot and Thermoneutral Ambient Temperature Conditions

    Directory of Open Access Journals (Sweden)

    Michelle L. E. Henry

    2016-06-01

    Full Text Available A controlled feeding study was undertaken to determine the physiological and production effects of consuming perennial ryegrass alkaloids (fed via seed under extreme heat in sheep. Twenty-four Merino ewe weaners (6 months; initial BW 30.8 ± 1.0 kg were selected and the treatment period lasted 21 days following a 14 day acclimatisation period. Two levels of two factors were used. The first factor was alkaloid, fed at a nil (NilAlk or moderate level (Alk; 80 μg/kg LW ergovaline and 20.5 μg/kg·LW lolitrem B. The second factor was ambient temperature applied at two levels; thermoneutral (TN; constant 21–22 °C or heat (Heat; 9:00 AM–5:00 PM at 38 °C; 5:00 PM–9:00 AM at 21–22 °C, resulting in four treatments, NilAlk TN, NilAlk Heat, Alk TN and Alk Heat. Alkaloid consumption reduced dry matter intake ( p = 0.008, and tended to reduce liveweight ( p = 0.07. Rectal temperature and respiration rate were increased by both alkaloid and heat ( p < 0.05 for all. Respiration rate increased to severe levels when alkaloid and heat were combined, indicating the short term effects which may be occurring in perennial ryegrass toxicosis (PRGT areas during severe weather conditions, a novel finding. When alkaloid ingestion and heat were administered separately, similar physiological responses occurred, indicating alkaloid ingestion causes a similar heat stress response to 38 °C heat.

  5. Correlation of rectal temperature and peripheral temperature from implantable radio-frequency microchips in Holstein steers challenged with lipopolysaccharide under thermoneutral and high ambient temperatures.

    Science.gov (United States)

    Reid, E D; Fried, K; Velasco, J M; Dahl, G E

    2012-12-01

    Early detection of disease can speed treatment, slow spread of disease in a herd, and improve health status of animals. Immune stimulation increases rectal temperature (RT). Injectable radio-frequency implants (RFI) can provide temperature at the site of implantation. The fidelity of peripheral site temperature, determined by RFI, relative to RT is unknown in cattle. We hypothesized that during lipopolysaccharide (LPS) challenge, temperature at 3 peripheral sites would be similar to RT in steers (n = 4; BW 77 ± 2.1 kg). The 3 sites were 1) subcutaneous (SC) at the base of the ear (ET); 2) SC posterior to the poll (PT); and 3) SC beneath the umbilical fold (UT). Steers were housed in controlled temperature (CT) rooms (between 18 and 21°C; n = 2/room). Rectal temperature, ET, PT, and UT were recorded every 8 h daily. On d 7, 21, 22, 36, and 37, RT and RFI were taken every 5 min for 6 h, every 15 min for 3 h, and every 30 min for 15 h. To test RFI during a simulated immune challenge, LPS (E. coli 055:B5) was injected intravenously (i.v.) at 1000 h on d 22 and 37. Basal temperatures (°C) were RT (38.7 ± 0.20), ET (37.1 ± 0.86), PT (36.7 ± 0.57), and UT (36.3 ± 0.97). Rectal temperature increased to 39.9 ± 0.30°C after LPS, but ET, PT, and UT decreased. Heat stress also increases RT, which makes it difficult to identify sick animals using RT. The second hypothesis tested was that ET positively correlates to RT and negatively correlates to RT during LPS under heat stress. Four steers (127 ± 7.3 kg) were housed in CT chambers (n = 2/chamber), implanted with a RFI, and allowed 2 wk to acclimate. One chamber remained at 20°C, the other was increased to 34°C starting at 0800 h for a period of 48 h. The LPS was administered i.v. to all steers at 1000 h on d 2. After a 2-wk recovery at 20°C, the temperature was increased in the other chamber, resulting in a crossover design with each steer serving as its own control. Pearson's correlation coefficients for ET and

  6. Modification of the association between high ambient temperature and health by urban microclimate indicators: A systematic review and meta-analysis.

    Science.gov (United States)

    Schinasi, Leah H; Benmarhnia, Tarik; De Roos, Anneclaire J

    2018-02-01

    Landscape characteristics, including vegetation and impervious surfaces, influence urban microclimates and may lead to within-city differences in the adverse health effects of high ambient temperatures. Our objective was to quantitatively summarize the epidemiologic literature that assessed microclimate indicators as effect measure modifiers (EMM) of the association between ambient temperature and mortality or morbidity. We systematically identified papers and abstracted relative risk estimates for hot and cool microclimate indicator strata. We calculated the ratio of the relative risks (RRR) and 95% confidence intervals (95% CI) to assess differences in health effects across strata, and pooled the RRR estimates using random effects meta-analyses. Eleven papers were retained. In the pooled analyses, people living in hotter areas within cities (based on land surface temperature or modeled estimates of air temperature) had 6% higher risk of mortality/morbidity compared to those in cooler areas (95% CI: 1.03-1.09). Those living in less vegetated areas had 5% higher risk compared to those living in more vegetated areas (95% CI: 1.00-1.11). There is epidemiologic evidence that those living in hotter, and less vegetated areas of cities have higher risk of morbidity or mortality from higher ambient temperature. Further research with improved assessment of landscape characteristics and investigation of the joint effects of physiologic adaptation and landscape will advance the current understanding. This review provides quantitative evidence that intra-urban differences in landscape characteristics and micro-urban heat islands contribute to within-city variability in the health effects of high ambient temperatures. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Disturbances in pro-oxidant-antioxidant balance after passive body overheating and after exercise in elevated ambient temperatures in athletes and untrained men.

    Science.gov (United States)

    Pilch, Wanda; Szygula, Zbigniew; Tyka, Anna K; Palka, Tomasz; Tyka, Aleksander; Cison, Tomasz; Pilch, Pawel; Teleglow, Aneta

    2014-01-01

    The aim of the study was to investigate pro-oxidant-antioxidant balance in two series of examinations with two types of stressors (exogenous heat and the combined exogenous and endogenous heat) in trained and untrained men. The exogenous stressor was provided by Finnish sauna session, whereas the combined stressor was represented by the exercise in elevated ambient temperature. The men from the two groups performed the physical exercise on a cycle ergometer with the load of 53 ± 2% maximal oxygen uptake at the temperature of 33 ± 1 °C and relative humidity of 70% until their rectal temperature rose by 1.2 °C. After a month from completion of the exercise test the subjects participated in a sauna bathing session with the temperature of 96 ± 2 °C, and relative humidity of 16 ± 5%. 15-minutes heating and 2-minute cool-down in a shower with the temperature of 20 °C was repeated until rectal temperature rose by 1.2 °C compared to the initial value. During both series of tests rectal temperature was measured at 5-minute intervals. Before both series of tests and after them body mass was measured and blood samples were taken for biochemical tests. Serum total protein, serum concentration of lipid peroxidation products and serum antioxidants were determined. The athletes were characterized by higher level of antioxidant status and lower concentration of lipid peroxidation products. Physical exercise at elevated ambient temperature caused lower changes in oxidative stress indices compared to sauna bathing. Sauna induced a shift in pro-oxidant-antioxidant balance towards oxidation, which was observed less intensively in the athletes compared to the untrained men. This leads to the conclusion that physical exercise increases tolerance to elevated ambient temperature and oxidative stress.

  8. Disturbances in Pro-Oxidant-Antioxidant Balance after Passive Body Overheating and after Exercise in Elevated Ambient Temperatures in Athletes and Untrained Men

    Science.gov (United States)

    Pilch, Wanda; Szygula, Zbigniew; Tyka, Anna K.; Palka, Tomasz; Tyka, Aleksander; Cison, Tomasz; Pilch, Pawel; Teleglow, Aneta

    2014-01-01

    The aim of the study was to investigate pro-oxidant-antioxidant balance in two series of examinations with two types of stressors (exogenous heat and the combined exogenous and endogenous heat) in trained and untrained men. The exogenous stressor was provided by Finnish sauna session, whereas the combined stressor was represented by the exercise in elevated ambient temperature. The men from the two groups performed the physical exercise on a cycle ergometer with the load of 53±2% maximal oxygen uptake at the temperature of 33±1°C and relative humidity of 70% until their rectal temperature rose by 1.2°C. After a month from completion of the exercise test the subjects participated in a sauna bathing session with the temperature of 96±2°C, and relative humidity of 16±5%. 15-minutes heating and 2-minute cool-down in a shower with the temperature of 20°C was repeated until rectal temperature rose by 1.2°C compared to the initial value. During both series of tests rectal temperature was measured at 5-minute intervals. Before both series of tests and after them body mass was measured and blood samples were taken for biochemical tests. Serum total protein, serum concentration of lipid peroxidation products and serum antioxidants were determined. The athletes were characterized by higher level of antioxidant status and lower concentration of lipid peroxidation products. Physical exercise at elevated ambient temperature caused lower changes in oxidative stress indices compared to sauna bathing. Sauna induced a shift in pro-oxidant-antioxidant balance towards oxidation, which was observed less intensively in the athletes compared to the untrained men. This leads to the conclusion that physical exercise increases tolerance to elevated ambient temperature and oxidative stress. PMID:24465535

  9. Monte Carlo simulations of the secondary neutron ambient and effective dose equivalent rates from surface to suborbital altitudes and low Earth orbit.

    Science.gov (United States)

    El-Jaby, Samy; Richardson, Richard B

    2015-07-01

    Occupational exposures from ionizing radiation are currently regulated for airline travel (Earth orbit (∼300-400 km). Aircrew typically receive between 1 and 6 mSv of occupational dose annually, while aboard the International Space Station, the area radiation dose equivalent measured over just 168 days was 106 mSv at solar minimum conditions. It is anticipated that space tourism vehicles will reach suborbital altitudes of approximately 100 km and, therefore, the annual occupational dose to flight crew during repeated transits is expected to fall somewhere between those observed for aircrew and astronauts. Unfortunately, measurements of the radiation environment at the high altitudes reached by suborbital vehicles are sparse, and modelling efforts have been similarly limited. In this paper, preliminary MCNPX radiation transport code simulations are developed of the secondary neutron flux profile in air from surface altitudes up to low Earth orbit at solar minimum conditions and excluding the effects of spacecraft shielding. These secondary neutrons are produced by galactic cosmic radiation interacting with Earth's atmosphere and are among the sources of radiation that can pose a health risk. Associated estimates of the operational neutron ambient dose equivalent, used for radiation protection purposes, and the neutron effective dose equivalent that is typically used for estimates of stochastic health risks, are provided in air. Simulations show that the neutron radiation dose rates received at suborbital altitudes are comparable to those experienced by aircrew flying at 7 to 14 km. We also show that the total neutron dose rate tails off beyond the Pfotzer maximum on ascension from surface up to low Earth orbit. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  10. Influence of sample temperature and environmental humidity on measurements of benzene in ambient air by transportable GC-PID

    Directory of Open Access Journals (Sweden)

    C. Romero-Trigueros

    2017-10-01

    Full Text Available Calibration of in situ analysers of air pollutants is usually done with dry standards. In this paper, the influence of sample temperature and environmental humidity on benzene measurements by gas chromatography coupled with a photoionisation detector (GC-PID is studied. Two reference gas mixtures (40 and 5 µg m−3 nominal concentration benzene in air were subjected to two temperature cycles (20/5/20 °C and 20/35/20 °C and measured with two identical GC-PIDs. The change in sample temperature did not produce any significant change in readings. Regarding ambient humidity, the chromatographs were calibrated for benzene with dry gases and subjected to measure reference standards with humidity (20 and 80 % at 20 °C. When measuring a concentration of 0.5 µg m−3 benzene in air, the levels of humidity tested did not produce any significant interference in measurements taken with any of the analysers. However, when measuring a concentration of 40 µg m−3, biases in measurements of 18 and 21 % for each respective analyser were obtained when the relative humidity of the sample was 80 % at 20 °C. Further tests were carried out to study the nature of this interference. Results show that humidity interference depends on both the amount fractions of water vapour and benzene. If benzene concentrations in an area are close to its annual limit value (5 µg m−3, biases of 2.2 % can be expected when the absolute humidity is 8.6 g cm−3 – corresponding to a relative humidity of 50 % at 20 °C. This can be accounted for in the uncertainty budget of measurements with no need for corrections. If benzene concentrations are above the annual limit value, biases become higher. Thus, in these cases, actions should be taken to reduce the humidity interference, as an underestimation of benzene concentrations may cause a mismanagement of air quality in these situations.

  11. Diurnal variations of airborne pollen concentration and the effect of ambient temperature in three sites of Mexico City.

    Science.gov (United States)

    Ríos, B; Torres-Jardón, R; Ramírez-Arriaga, E; Martínez-Bernal, A; Rosas, I

    2016-05-01

    Pollen is an important cause of allergic respiratory ailments in the Mexico City Metropolitan Area (MCMA). However, very little is known if ambient air temperature correlates with the early blooming of plants observed in other urban areas around the world. A research study was conducted during the dry season of 2012-2013 at three representative sites of the MCMA with different urban characteristics with the aim to understand the relationships between the profusion and diversity of pollen against temperature and other meteorological variables and degree of urbanization. Pollen samples were collected using a Hirst-type trap sampler in the sites: Merced (highly urbanized), Iztapalapa (medium-high urbanized) and Coyoacan (moderately urbanized). Urbanization levels were determined using a composite index based on population density, proportion of surface covered by construction and asphalt, and urban heat island intensity. A set of representative pollen sampling tapes were assayed under a light microscope at magnification of ×1,000 and converted to grains per cubic meter. The most representative pollen types found in the three sites were, regardless of urbanization levels were: Fraxinus, Cupressaceae/Taxodiaceae, Casuarina, Alnus, Myrtaceae, and Pinus. Total pollen concentration was greatest in the moderately urbanized area, although earlier blooming took place at the highly urbanized zone. Total pollen concentration in the medium-high urbanized site has the lowest because the green areas in this zone of MCMA are few. In a diurnal basis, the most abundant pollen types peaked near midday or in the afternoon evening at the three sites. A Spearman test showed a positive correlation among bihourly pollen concentrations, temperature and relative humidity in all sites, but wind speed just correlated in Iztapalapa and Coyoacan. The results obtained suggest that Urban Heat Island Intensity can disturb flowering periods and pollen concentrations, largely in the highly urbanized

  12. [Effect of temperature on activity of Acidithiobacillus ferrooxidan and formation of biogenic secondary iron minerals].

    Science.gov (United States)

    Song, Yong-Wei; Zhao, Bo-Wen; Huo, Min-Bo; Cui, Chun-Hong; Zhou, Li-Xiang

    2013-08-01

    In this study, batch experiments were performed to investigate the effect of temperature on the Fe (II) oxidation and the formation of biogenic secondary iron minerals by Acidithiobacillus ferrooxidan. Results showed that the low temperature significantly inhibited the oxidation activity of A. ferrooxidan. In the FeSO4-H2O biological oxidation system facilitated by A. ferrooxidan, it was found that after 5 days culture, the oxidation rates of Fe (II) in treatments of 10 degrees C and 28 degrees C were 11.81% and 100%, respectively. In addition, it rapidly rose to 95.10% when the temperature was adjusted from 10 degrees C (cultured for 7 days) to 28 degrees C in 1 day, and the maximum oxidation rates were as follows: 10 degrees C (cultured for 7 days) +28 degrees C (2.25 h(-1)) > 28 degrees C (1.42 h(-1)) >10 degrees C (0.81 h(-1)). Furthermore, the XRD patterns showed that the lower Fe (III) supply rate was more conducive to the formation of amorphous schwertmannite in 9K medium at 10 degrees C. Correspondingly, the generation of amorphous schwertmannite was preceded to ihleite at 28 degrees C, and the crystallinity degree of ihleite was getting better with the extension of culture time. Combined with the SEM characteristics, it was judged that the 28 degrees C sample contained jarosite and schwertmannite.

  13. Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Tian, Shulei [Tsinghua Univ., Beijing (China). Dept. of Environmental Science and Engineering; Wang, Qi [Chinese Research Academy of Environmental Science, Beijing (China); Wu, Ziyu [Chinese Academy of Sciences, Beijing (China). Inst. of High Energy Physics; Univ. of Science and Technology of China, Hefei (China). National Synchrotron Radiation Lab.; Chinese Academy of Sciences, Beijing (China). Theoretical Physics Center for Science Facilities

    2009-07-15

    The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

  14. Speciation of zinc in secondary fly ashes of municipal solid waste at high temperatures

    International Nuclear Information System (INIS)

    Yu, Meijuan; Chu, Wangsheng; Chen, Dongliang; Wu, Ziyu; Univ. of Science and Technology of China, Hefei; Chinese Academy of Sciences, Beijing

    2009-01-01

    The evaporation aerosols produced during the vitrification process of municipal solid waste incinerators (MSWI) fly ash represent a potential environmental risk owing to their high content of heavy metals. In this research, high-temperature heating processes were carried out on fly ashes collected from bag houses in a Chinese MSWI plant and the secondary fly ashes (SFA) were separately collected at three high temperatures (1273 K, 1423 K and 1523 K) below the melting range. Elemental analysis showed that high contents of both zinc and chlorine were present in these SFA samples and, according to the standard of the heavy metals industrial grade of ore, SFAs can be re-used as metallurgical raw materials or rich ore. Moreover, as shown by XAS analysis and for different high temperatures, zinc environments in the three SFA samples were characterized by the same local structure of the zinc chloride. As a consequence, a zinc recycling procedure can be easily designed based on the configuration information. (orig.)

  15. Variability of Battery Wear in Light Duty Plug-In Electric Vehicles Subject to Ambient Temperature, Battery Size, and Consumer Usage: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Wood, E.; Neubauer, J.; Brooker, A. D.; Gonder, J.; Smith, K. A.

    2012-08-01

    Battery wear in plug-in electric vehicles (PEVs) is a complex function of ambient temperature, battery size, and disparate usage. Simulations capturing varying ambient temperature profiles, battery sizes, and driving patterns are of great value to battery and vehicle manufacturers. A predictive battery wear model developed by the National Renewable Energy Laboratory captures the effects of multiple cycling and storage conditions in a representative lithium chemistry. The sensitivity of battery wear rates to ambient conditions, maximum allowable depth-of-discharge, and vehicle miles travelled is explored for two midsize vehicles: a battery electric vehicle (BEV) with a nominal range of 75 mi (121 km) and a plug-in hybrid electric vehicle (PHEV) with a nominal charge-depleting range of 40 mi (64 km). Driving distance distributions represent the variability of vehicle use, both vehicle-to-vehicle and day-to-day. Battery wear over an 8-year period was dominated by ambient conditions for the BEV with capacity fade ranging from 19% to 32% while the PHEV was most sensitive to maximum allowable depth-of-discharge with capacity fade ranging from 16% to 24%. The BEV and PHEV were comparable in terms of petroleum displacement potential after 8 years of service, due to the BEV?s limited utility for accomplishing long trips.

  16. Influence of day length, ambient temperature, and seasonality on daily travel distance in the Yunnan snub-nosed monkey at Jinsichang, Yunnan, China.

    Science.gov (United States)

    Baoping, Ren; Ming, Li; Yongcheng, Long; Fuwen, Wei

    2009-03-01

    This article examines the effect of ambient temperature, day length, weather conditions, and seasonality on daily path length (DPL) of a free-ranging group of Yunnan snub-nosed monkeys (Rhinopithecus bieti) using an auto-released GPS collar. Data were collected from December 17, 2003 to October 22, 2004 at Laojunshan in northwestern Yunnan province, China. The average DPL of the monkey group was 909+/-472 m (n=291), with the shortest distance being 180 m and the longest distance 3,626 m. Ambient temperature and day length were found to affect DPL. Both factors were positively correlated with DPL, which means that the monkey group traveled greater distances on longer and warmer days. At the study site, three distinct seasons were identified, and DPL did not vary significantly across these periods. The time of sunrise was not correlated with DPL. Nevertheless, we sometimes observed the group starting its daily trip later on cloudy days than on sunny days. Furthermore, weather conditions (e.g. rainy, cloudy, and sunny) did not influence the average DPL of the study group. Overall we found that the primary factors affecting DPL in R. bieti were day length and ambient temperature, especially daily highest temperature. (c) 2008 Wiley-Liss, Inc.

  17. Method of forming components for a high-temperature secondary electrochemical cell

    Science.gov (United States)

    Mrazek, F.C.; Battles, J.E.

    1981-05-22

    A method of forming a component for a high-temperature secondary electrochemical cell having a positive electrode including a sulfide selected from the group consisting of iron sulfides, nickel sulfides, copper sulfides and cobalt sulfides, a negative electrode including an alloy of aluminum and an electrically insulating porous separator between said electrodes is described. The improvement comprises forming a slurry of solid particles dispersed in a liquid electrolyte such as the lithium chloride-potassium chloride eutectic, casting the slurry into a form having the shape of one of the components and smoothing the exposed surface of the slurry, cooling the cast slurry to form the solid component, and removing same. Electrodes and separators can be thus formed.

  18. EBR-II secondary sodium loop Plugging Temperature Indicator control system upgrade

    International Nuclear Information System (INIS)

    Carlson, R.B.; Gehrman, R.L.

    1995-01-01

    The Experimental Breeder Reactor II (EBR-II) secondary sodium coolant loop Plugging Temperature Indicator (PTI) control system was upgraded in 1993 to a real-time computer based system. This was done to improve control, to remove obsolete and high maintenance equipment, and to provide a graphical CRT based operator interface. A goal was to accomplish this inexpensively using small, reliable computer and display hardware with a minimum of purchased software. This paper describes the PTI system, the upgraded control system and its operator interface, and development methods and tools. The paper then assesses how well the system met its goals, discusses lessons learned and operational improvements noted, and provides some recommendations and suggestions on applying small real-time control systems of this type

  19. Experimental study on the effect of ambient temperature on ready-mix concrete strength. Part 2: Industrial implementation

    Directory of Open Access Journals (Sweden)

    Puig Montraveta, J.

    2010-06-01

    Full Text Available This paper is the second part of an experimental study about the effect of environmental temperature on the concrete performance, from an industrial perspective. An earlier article on its effect on aggregate, paste, mortar and concrete workability and mechanical properties reported that high temperature had a clearly adverse impact on strength, which can generally be offset with overdoses of both cement and water to maintain the original water/cement ratio. In this second part of the paper the basis of a methodological formulation is presented, with the purpose of carry out the optimization of the overdosage of cement in concrete in hot climates, in order to be industrially implemented in ready mix concrete plants. This proposal has been successfully applied in some ready mix concrete plants of the company Promotora Mediterránea 2, S.A. (PROMSA, considering that the cement content (overdosage in concrete can be optimized without any adverse effect in its performance, reason why it is possible to reduce the production costs of concrete without reducing its quality.

    El presente artículo constituye la segunda parte de un estudio experimental sobre la influencia de la temperatura ambiental sobre las prestaciones del hormigón, desde una perspectiva industrial. En la primera, se estudió el efecto sobre las propiedades de trabajabilidad y mecánicas, en áridos, pasta, mortero y hormigones, detectando un claro efecto negativo de la temperatura elevada sobre la resistencia, que se suele solucionarcon una sobredosificación en cemento y agua, para mantenerla relación agua/cemento original.En esta segunda parte del artículo, se presentan las bases de una formulación metodológica para llevar a cabo la optimización de la sobredosificación de cemento en el hormigón en climas cálidos, para ser implementada industrialmente en plantas de hormigón preparado. Dicha propuesta se ha aplicado con éxito a escala industrial en plantas de producci

  20. Dietary enzymatically treated Artemisia annua L. supplementation alleviates liver oxidative injury of broilers reared under high ambient temperature

    Science.gov (United States)

    Wan, Xiaoli; Zhang, Jingfei; He, Jintian; Bai, Kaiwen; Zhang, Lili; Wang, Tian

    2017-09-01

    Heat stress induced by high ambient temperature is a major concern in commercial broiler production. To evaluate the effects of dietary enzymatically treated Artemisia annua L. (EA) supplementation on growth performance and liver oxidative injury of broilers reared under heat stress, a total of 320 22-day-old male broilers were randomly allotted into five groups with eight replicates of eight birds each. Broilers in the control group were housed at 22 ± 1 °C and fed the basal diet. Broilers in the HS, HS-EA1, HS-EA2, and HS-EA3 groups were fed basal diet supplemented with 0, 0.75, 1.00, and 1.25 g/kg EA, respectively, and reared under cyclic high temperature (34 ± 1 °C for 8 h/day and 22 ± 1 °C for 16 h/day). Broilers fed EA diets had higher final body weight, average daily body weight gain, and average daily feed intake, as well as liver concentration of reduced glutathione, activities of antioxidant enzymes, abilities to inhibit hydroxyl radical and superoxide radical (HS-EA2 and HS-EA3), and lower liver concentrations of reactive oxygen metabolites, malondialdehyde, and protein carbonyl (HS-EA1, HS-EA2, and HS-EA3) than HS group ( P < 0.05). EA treatment downregulated the mRNA levels of heat shock proteins 70 and 90, upregulated the mRNA levels of nuclear factor erythroid 2-related factor 2 (HS-EA1, HS-EA2, and HS-EA3) and heme oxygenase 1 (HS-EA2 and HS-EA3) in liver of heat-treated broilers ( P < 0.05). In conclusion, EA alleviated heat stress-induced growth depression and liver oxidative injury in broilers, possibly through improving the antioxidant capacity and regulating the pertinent mRNA expression. The appropriate inclusion level of EA in broiler diet is 1.00-1.25 g/kg.

  1. α-Pinene secondary organic aerosol at low temperature: chemical composition and implications for particle viscosity

    Science.gov (United States)

    Huang, Wei; Saathoff, Harald; Pajunoja, Aki; Shen, Xiaoli; Naumann, Karl-Heinz; Wagner, Robert; Virtanen, Annele; Leisner, Thomas; Mohr, Claudia

    2018-02-01

    Chemical composition, size distributions, and degree of oligomerization of secondary organic aerosol (SOA) from α-pinene (C10H16) ozonolysis were investigated for low-temperature conditions (223 K). Two types of experiments were performed using two simulation chambers at the Karlsruhe Institute of Technology: the Aerosol Preparation and Characterization (APC) chamber, and the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) chamber. Experiment type 1 simulated SOA formation at upper tropospheric conditions: SOA was generated in the AIDA chamber directly at 223 K at 61 % relative humidity (RH; experiment termed cold humid, CH) and for comparison at 6 % RH (experiment termed cold dry, CD) conditions. Experiment type 2 simulated SOA uplifting: SOA was formed in the APC chamber at room temperature (296 K) and warm dry, WD) or 21 % RH (experiment termed warm humid, WH) conditions, and then partially transferred to the AIDA chamber kept at 223 K, and 61 % RH (WDtoCH) or 30 % RH (WHtoCH), respectively. Precursor concentrations varied between 0.7 and 2.2 ppm α-pinene, and between 2.3 and 1.8 ppm ozone for type 1 and type 2 experiments, respectively. Among other instrumentation, a chemical ionization mass spectrometer (CIMS) coupled to a filter inlet for gases and aerosols (FIGAERO), deploying I- as reagent ion, was used for SOA chemical composition analysis. For type 1 experiments with lower α-pinene concentrations and cold SOA formation temperature (223 K), smaller particles of 100-300 nm vacuum aerodynamic diameter (dva) and higher mass fractions (> 40 %) of adducts (molecules with more than 10 carbon atoms) of α-pinene oxidation products were observed. For type 2 experiments with higher α-pinene concentrations and warm SOA formation temperature (296 K), larger particles ( ˜ 500 nm dva) with smaller mass fractions of adducts (climate models.

  2. Milk and Blood Cortisol and T3 Hormones Content and Milk Composition in Buffaloes as a Function of Lactating Number and Ambient Temperature

    International Nuclear Information System (INIS)

    Habeeb Alsaied, A.M.; Ibahim, M.KH.

    1998-01-01

    The effect of lactating number and ambient temperature on T 3 and cortisol levels in each of milk and blood and milk composition of lactating Water buffaloes was the objective of this study. The experiment was carried out on 72 animals including two periods through 1994. The first was carried out on 36 animals in February where the average of ambient temperature was 17.5 degree, while the second was conducted on another 36 animals in July where the average of ambient temperature was 37.1 degree . In both two periods, the animals were classified according to lactating number into 6 equal groups from the 1st to 6 th lactation number. The data showed that milk yield and T 3 , either in milk or in blood and milk fat, protein and lactose were significantly lower in July than in February. Whereas the opposite was true with cortisol level either in milk or in blood. Concerning the effect of lactation number, it was observed that milk and blood T 3 , milk and blood cortisol and milk fat, protein and lactose were affected significantly due to lactation number

  3. Economic benefits of keeping vaccines at ambient temperature during mass vaccination: the case of meningitis A vaccine in Chad.

    Science.gov (United States)

    Lydon, Patrick; Zipursky, Simona; Tevi-Benissan, Carole; Djingarey, Mamoudou Harouna; Gbedonou, Placide; Youssouf, Brahim Oumar; Zaffran, Michel

    2014-02-01

    To evaluate the potential economic benefits of keeping a meningitis A vaccine at or near ambient temperature for up to 4 days during a mass vaccination campaign. During a 10-day mass vaccination campaign against meningitis A in three regions of Chad in 2011, the costs associated with storage and transport of the vaccine in a traditional cold chain system were evaluated. A mathematical model was used to estimate the savings that could have been achieved if the vaccine had been stored at or near ambient temperature--in a "controlled temperature" chain--at the peripheral levels of the supply chain system. The cost of the cold chain and associated logistics used in the campaign in Chad was 0.24 United States dollars (US$) per person vaccinated. In the modelled scenario for a controlled temperature chain, however, these costs dropped by 50% and were estimated to be only US$ 0.12 per person vaccinated. The implementation of a "controlled temperature" chain at the most peripheral levels of the supply chain system--assuming no associated loss of vaccine potency, efficacy or safety--could result in major economic benefits and allow vaccine coverage to be extended in low-resource settings.

  4. Low temperature and moisture swing sorption of CO2 from ambient air using a Na-based adsorbent

    NARCIS (Netherlands)

    Rodriguez Mosqueda, Rafael; Brem, Gerrit; Bramer, Eduard A.

    2017-01-01

    The continuous increase of the carbon dioxide concentration in the atmosphere is a recognized problem that will lead the humanity to catastrophic scenarios unless it is drastically reduced. One option to tackle this issue is to retrieve CO2 directly from ambient air, which has the advantage that it

  5. Ambient Space and Ambient Sensation

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central...

  6. Heat or Cold: Which One Exerts Greater Deleterious Effects on Health in a Basin Climate City? Impact of Ambient Temperature on Mortality in Chengdu, China.

    Science.gov (United States)

    Cui, Yan; Yin, Fei; Deng, Ying; Volinn, Ernest; Chen, Fei; Ji, Kui; Zeng, Jing; Zhao, Xing; Li, Xiaosong

    2016-12-10

    Background : Although studies from many countries have estimated the impact of ambient temperature on mortality, few have compared the relative impacts of heat and cold on health, especially in basin climate cities. We aimed to quantify the impact of ambient temperature on mortality, and to compare the contributions of heat and cold in a large basin climate city, i.e., Chengdu (Sichuan Province, China); Methods : We estimated the temperature-mortality association with a distributed lag non-linear model (DLNM) with a maximum lag-time of 21 days while controlling for long time trends and day of week. We calculated the mortality risk attributable to heat and cold, which were defined as temperatures above and below an "optimum temperature" that corresponded to the point of minimum mortality. In addition, we explored effects of individual characteristics; Results : The analysis provides estimates of the overall mortality burden attributable to temperature, and then computes the components attributable to heat and cold. Overall, the total fraction of deaths caused by both heat and cold was 10.93% (95%CI: 7.99%-13.65%). Taken separately, cold was responsible for most of the burden (estimate 9.96%, 95%CI: 6.90%-12.81%), while the fraction attributable to heat was relatively small (estimate 0.97%, 95%CI: 0.46%-2.35%). The attributable risk (AR) of respiratory diseases was higher (19.69%, 95%CI: 14.45%-24.24%) than that of cardiovascular diseases (11.40%, 95%CI: 6.29%-16.01%); Conclusions : In Chengdu, temperature was responsible for a substantial fraction of deaths, with cold responsible for a higher proportion of deaths than heat. Respiratory diseases exert a larger effect on death than other diseases especially on cold days. There is potential to reduce respiratory-associated mortality especially among the aged population in basin climate cities when the temperature deviates beneath the optimum. The result may help to comprehensively assess the impact of ambient

  7. An investigation of a low-variability tire treadwear test procedure and of treadwear adjustment for ambient temperature. Volume 2 : appendices A, B, C, D and E, test data files

    Science.gov (United States)

    1985-01-01

    This volume is the first part of a two-part appendix to the report on a low variability : tire treadwear procedure and treadwear adjustment for ambient : temperature. This volume contains Appendices A through E, covering data sheets : describing equi...

  8. An investigation of a low-variability tire treadwear test procedure and of treadwear adjustment for ambient temperature. Volume 3 : appendices F, G, H, I, J and K, analytical files

    Science.gov (United States)

    1985-01-01

    This volume is the second part of a two-part appendix to the report on a low variability : tire treadwear procedure and treadwear adjustment for ambient : temperature. This volume contains Appendices F through K, covering the fundamental : statistica...

  9. Seasonality and ambient temperature at time of conception in term-born individuals - influences on cardiovascular disease and obesity in adult life.

    Science.gov (United States)

    Schreier, Nadja; Moltchanova, Elena; Forsén, Tom; Kajantie, Eero; Eriksson, Johan G

    2013-01-01

    The influence of environmental conditions early in life - including temperature and season - on health later in life has so far not attracted much attention. Using data from the Helsinki Birth Cohort Study of 13,345 men and women, the influence of temperature and season at month of conception on birth weight, and on cardiovascular diseases and obesity-related traits in later life was studied. Linear regressions were fitted to examine the relationship between birth weight/obesity-related variables/hypertension and alternatively month of conception and average temperature of month of conception. The incidence of both coronary heart disease and cerebrovascular disease was assumed to follow a Weibull hazard model, and was modelled accordingly using survival analysis techniques. In women, unusually cold temperatures at month of conception predicted lower body mass index (BMI) and fat percentage, and protected from obesity. Warmer temperatures at month of conception were associated with higher risk for hypertension. In men, warmer temperatures around conception predicted lower BMI. No seasonal influences were detected on obesity-related variables, nor were there seasonal or temperature mediated influences on birth weight, coronary heart disease or cerebrovascular disease observed. We suggest that ambient temperature has an influence on obesity-related outcomes and hypertension. This merits further study, also with regard to other health outcomes and from a global perspective.

  10. Heat or Cold: Which One Exerts Greater Deleterious Effects on Health in a Basin Climate City? Impact of Ambient Temperature on Mortality in Chengdu, China

    Directory of Open Access Journals (Sweden)

    Yan Cui

    2016-12-01

    Full Text Available Background: Although studies from many countries have estimated the impact of ambient temperature on mortality, few have compared the relative impacts of heat and cold on health, especially in basin climate cities. We aimed to quantify the impact of ambient temperature on mortality, and to compare the contributions of heat and cold in a large basin climate city, i.e., Chengdu (Sichuan Province, China; Methods: We estimated the temperature-mortality association with a distributed lag non-linear model (DLNM with a maximum lag-time of 21 days while controlling for long time trends and day of week. We calculated the mortality risk attributable to heat and cold, which were defined as temperatures above and below an “optimum temperature” that corresponded to the point of minimum mortality. In addition, we explored effects of individual characteristics; Results: The analysis provides estimates of the overall mortality burden attributable to temperature, and then computes the components attributable to heat and cold. Overall, the total fraction of deaths caused by both heat and cold was 10.93% (95%CI: 7.99%–13.65%. Taken separately, cold was responsible for most of the burden (estimate 9.96%, 95%CI: 6.90%–12.81%, while the fraction attributable to heat was relatively small (estimate 0.97%, 95%CI: 0.46%–2.35%. The attributable risk (AR of respiratory diseases was higher (19.69%, 95%CI: 14.45%–24.24% than that of cardiovascular diseases (11.40%, 95%CI: 6.29%–16.01%; Conclusions: In Chengdu, temperature was responsible for a substantial fraction of deaths, with cold responsible for a higher proportion of deaths than heat. Respiratory diseases exert a larger effect on death than other diseases especially on cold days. There is potential to reduce respiratory-associated mortality especially among the aged population in basin climate cities when the temperature deviates beneath the optimum. The result may help to comprehensively assess the

  11. Serial femtosecond X-ray diffraction of 30S ribosomal subunit microcrystals in liquid suspension at ambient temperature using an X-ray free-electron laser

    International Nuclear Information System (INIS)

    Demirci, Hasan; Sierra, Raymond G.; Laksmono, Hartawan; Shoeman, Robert L.; Botha, Sabine; Barends, Thomas R. M.; Nass, Karol; Schlichting, Ilme; Doak, R. Bruce; Gati, Cornelius; Williams, Garth J.; Boutet, Sébastien; Messerschmidt, Marc; Jogl, Gerwald; Dahlberg, Albert E.; Gregory, Steven T.; Bogan, Michael J.

    2013-01-01

    Serial femtosecond X-ray (SFX) diffraction extending beyond 6 Å resolution using T. thermophilus 30S ribosomal subunit crystals is reported. High-resolution ribosome structures determined by X-ray crystallography have provided important insights into the mechanism of translation. Such studies have thus far relied on large ribosome crystals kept at cryogenic temperatures to reduce radiation damage. Here, the application of serial femtosecond X-ray crystallography (SFX) using an X-ray free-electron laser (XFEL) to obtain diffraction data from ribosome microcrystals in liquid suspension at ambient temperature is described. 30S ribosomal subunit microcrystals diffracted to beyond 6 Å resolution, demonstrating the feasibility of using SFX for ribosome structural studies. The ability to collect diffraction data at near-physiological temperatures promises to provide fundamental insights into the structural dynamics of the ribosome and its functional complexes

  12. Thermo-economic optimization of secondary distribution network of low temperature district heating network under local conditions of South Korea

    DEFF Research Database (Denmark)

    Park, Byung Sik; Imran, Muhammad; Hoon, Im-Yong

    2017-01-01

    A secondary distribution network of a low temperature district heating system is designed and optimized for a residential apartment complex under the local conditions of South Korea in the TRNSYS simulation environment. The residential apartment complex is a typical example of Korean residential...... °C, area of heat exchanger is increased by 68.2%, pumping power is also increased by 9.8% and heat loss is reduced by 15.6%. These results correspond to a temperature difference of 20 °C, the standard temperature difference in South Korea residential heating system. Economic assessment...

  13. Effects of dietary Spirulina on antioxidant status, lipid profile, immune response and performance characteristics of broiler chickens reared under high ambient temperature

    Science.gov (United States)

    Hosseini, Seyed Abdollah

    2018-01-01

    Objective Spirulina has been recognized formerly as a filamentous spiral-shaped blue-green algae but more recently as a genus of photosynthetic bacteria (Arthrospira). This microorganism is considered as a rich source of essential nutrients for human and animals. The present study was conducted to determine potential application of Spirulina for heat-exposed broilers. Methods Two hundred and fifty Cobb 500 chicks with male to female in equal ratio with average initial weight of 615.6 g at 17 days of age were divided into 5 treatments with 5 replicates of 10 chicks. Treatment groups were as follows: positive and negative controls with 0% Spirulina supplement and three Spirulina receiving groups with 5 g/kg (0.5%), 10 g/kg (1%), and 20 g/kg (2%) supplementation. Spirulina receiving groups as well as positive control were exposed to high ambient temperature at 36°C for 6 h/d from 38 to 44 days of age. Biochemical variables were measured in serum samples at 35, 38, 42, and 45 days of broiler chickens age. Results The results showed that supplementation of the diet with Spirulina decreased concentration of stress hormone and some serum lipid parameters while enhanced humoral immunity response and elevated antioxidant status whereas it didn’t meaningfully affect performance characteristics. Nevertheless, feed conversion ratio was improved numerically but not statistically in broilers fed with 1% Spirulina under high ambient temperature. Conclusion Overall, the present study suggests that alleviation of adverse impacts due to high ambient temperature at biochemical level including impaired enzymatic antioxidant system, elevated stress hormone and lipid profile can be approached in broiler chickens through supplementation of the diet with Spirulina platensis. PMID:28920419

  14. Effect of different levels of alpha tocopherol on performance traits, serum antioxidant enzymes, and trace elements in Japanese quail ( Coturnix coturnix japonica under low ambient temperature

    Directory of Open Access Journals (Sweden)

    Assar Ali Shah

    Full Text Available ABSTRACT This study was designed to find the effect of vitamin E supplementation on growth, serum antioxidant enzymes, and some trace elements in Japanese quail (Coturnix coturnix japonica under low ambient temperature. A total of 180 day-old Japanese quails were randomly divided into four groups and provided with 0 (group A, 50 (group B, 100 (group C, and 150 IU/kg (group D vitamin E (dl-α-tocopherol acetate under an average temperature of 9±0.5 °C for an experimental period of 42 days. The result showed that feed intake per day, body weight, weight gain per day, and feed conversion ratio did not differ significantly between the groups. Serum concentrations of superoxide and glutathione peroxidase were significantly high in birds supplemented with 150 mg/kg of vitamin E. The concentration of aspartate aminotransferase was not significantly affected between the control and treated groups; however, alanine transaminase concentration significantly reduced in group D. Zinc concentration in the blood increased significantly in group D, with no significant effect on copper and manganese between the control and treated groups. Vitamin E at the level of 150 IU/kg of feed improves the blood antioxidant status and zinc concentration, with no effect on the performance traits of quail reared under low ambient temperature.

  15. Technology Development Roadmap for the Advanced High Temperature Reactor Secondary Heat Exchanger

    Energy Technology Data Exchange (ETDEWEB)

    P. Sabharwall; M. McCllar; A. Siahpush; D. Clark; M. Patterson; J. Collins

    2012-09-01

    This Technology Development Roadmap (TDRM) presents the path forward for deploying large-scale molten salt secondary heat exchangers (MS-SHX) and recognizing the benefits of using molten salt as the heat transport medium for advanced high temperature reactors (AHTR). This TDRM will aid in the development and selection of the required heat exchanger for: power production (the first anticipated process heat application), hydrogen production, steam methane reforming, methanol to gasoline production, or ammonia production. This TDRM (a) establishes the current state of molten salt SHX technology readiness, (b) defines a path forward that systematically and effectively tests this technology to overcome areas of uncertainty, (c) demonstrates the achievement of an appropriate level of maturity prior to construction and plant operation, and (d) identifies issues and prioritizes future work for maturing the state of SHX technology. This study discusses the results of a preliminary design analysis of the SHX and explains the evaluation and selection methodology. An important engineering challenge will be to prevent the molten salt from freezing during normal and off-normal operations because of its high melting temperature (390°C for KF ZrF4). The efficient transfer of energy for industrial applications depends on the ability to incorporate cost-effective heat exchangers between the nuclear heat transport system and industrial process heat transport system. The need for efficiency, compactness, and safety challenge the capabilities of existing heat exchanger technology. The description of potential heat exchanger configurations or designs (such as printed circuit, spiral or helical coiled, ceramic, plate and fin, and plate type) were covered in an earlier report (Sabharwall et al. 2011). Significant future work, much of which is suggested in this report, is needed before the benefits and full potential of the AHTR can be realized. The execution of this TDRM will focuses

  16. The effect of irradiation temperatures between ambient and 80 deg. C on the response of alanine dosimeters

    DEFF Research Database (Denmark)

    Sharpe, P.H.G.; Miller, Arne; Sephton, J.P.

    2009-01-01

    dosimeters at temperatures up to 80 °C and doses up to 70 kGy. Data have been obtained for both 60Co and electron beam irradiations and the effect of temperature on the stability of the radiation-induced signal has also been investigated. At temperatures above 50 °C the irradiation temperature coefficient......Published data on the effect of irradiation temperature on the response of alanine dosimeters does not extend to the temperatures that may be experienced in high-dose industrial irradiations, particularly in the case of electron beams. We describe here results of the irradiation of alanine...

  17. Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

    Directory of Open Access Journals (Sweden)

    Bąk Joanna

    2018-01-01

    Full Text Available At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water – air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

  18. Measurements of water temperature in fountains as an indicator of potential secondary water pollution caused by Legionella bacteria

    Science.gov (United States)

    Bąk, Joanna

    2018-02-01

    At high air temperatures persisting for a long time, water temperature in the fountains may also increase significantly. This can cause a sudden and significant increase in Legionella bacteria, which results in secondary water contamination. This phenomenon with water - air aerosol generated by fountains can be very dangerous for people. During the test, water temperature measurements in fountains in Poland were made. These research tests was conducted in the spring and summer. The research was conducted in order to determine whether there is a possibility of growth of Legionella bacteria. One of the aims of the study was to determine what temperature range occurs in the fountains and how the temperature changes in the basin of the fountain and when the highest temperature occurs. Single temperature measurements were made and also the temperature distribution was measured during daylight hours. The water temperature in most cases was greater than 20°C, but in no case exceed 26°C. The paper presents also the review about the effect of water temperature on the presence and bacterial growth. The study confirmed the existence of the risk of increasing the number of bacteria of the genus Legionella in the water in the fountains.

  19. Effect of different arbuscular mycorrhizal fungi on growth and physiology of maize at ambient and low temperature regimes

    DEFF Research Database (Denmark)

    Chen, Xiaoying; Song, Fengbin; Liu, Fulai

    2014-01-01

    and soluble sugar contents under low temperature condition. The activities of catalase (CAT) and peroxidase of AM inoculated maize were higher than those of non-AM ones. Low temperature noticeably decreased the activities of CAT. The results suggest that low temperature adversely affects maize physiology...

  20. The effects of ambient temperature and mixing time of glass ionomer cement material on the survival rate of proximal ART restorations in primary molars

    Directory of Open Access Journals (Sweden)

    Arthur M Kemoli

    2014-01-01

    Full Text Available Objective: Temperature fluctuations and material mixing times are likely to affect the consistency and integrity of the material mixture, and hence the restoration made out of it. The purpose of the present study was to determine the influence of the ambient temperature and the mixing time of glass ionomer cement (GIC restorative material on the survival rate of proximal atraumatic restorative treatment (ART restorations placed in primary molars. Materials and Methods: A total of 804 restorations were placed in the primary molars of 6-8-year-olds using the ART approach. The restorations were then followed for a period of 2 years and evaluated at given intervals. The data collected were analyzed using SPSS computer statistical program, and the results tested and compared using the Chi-square, Kaplan Meier survival analysis and Cox Proportional hazard statistical tests. Results: The cumulative survival rate of the restorations dropped from the initial 94.4% to 30.8% at the end of 2 years. The higher survival rate of the restorations was associated with the experienced operators and assistants when using the rubber dam isolation method. However, there was no statistically significant difference in the survival rate of the restorations when related to the room temperature and the mixing time of the GIC materials used in spite of the variations in the temperature recoded and the methods used in mixing the materials. Conclusion: The ambient temperature and mixing time of GIC did not have a significant effect on the survival of the proximal ART restorations.

  1. Gene expression analysis of disabled and re-induced isoprene emission by the tropical tree Ficus septica before and after cold ambient temperature exposure.

    Science.gov (United States)

    Mutanda, Ishmael; Saitoh, Seikoh; Inafuku, Masashi; Aoyama, Hiroaki; Takamine, Tomonori; Satou, Kazuhito; Akutsu, Masako; Teruya, Kuniko; Tamotsu, Hinako; Shimoji, Makiko; Sunagawa, Haruki; Oku, Hirosuke

    2016-07-01

    Isoprene is the most abundant type of nonmethane, biogenic volatile organic compound in the atmosphere, and it is produced mainly by terrestrial plants. The tropical tree species Ficus septica Burm. F. (Rosales: Moraceae) has been shown to cease isoprene emissions when exposed to temperatures of 12 °C or lower and to re-induce isoprene synthesis upon subsequent exposure to temperatures of 30 °C or higher for 24 h. To elucidate the regulation of genes underlying the disabling and then induction of isoprene emission during acclimatization to ambient temperature, we conducted gene expression analyses of F. septica plants under changing temperature using quantitative real-time polymerase chain reaction and western blotting. Transcription levels were analyzed for 17 genes that are involved in metabolic pathways potentially associated with isoprene biosynthesis, including isoprene synthase (ispS). The protein levels of ispS were also measured. Changes in transcription and protein levels of the ispS gene, but not in the other assessed genes, showed identical temporal patterns to isoprene emission capacity under the changing temperature regime. The ispS protein levels strongly and positively correlated with isoprene emission capacity (R(2) = 0.92). These results suggest that transcriptional regulation of ispS gave rise to the temporal variation in isoprene emission capacity in response to changing temperature. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  2. The effect of ambient temperature and type of wound on healing of cutaneous wounds in the common garter snake (Thamnophis sirtalis).

    Science.gov (United States)

    Smith, D A; Barker, I K; Allen, O B

    1988-01-01

    The effects of ambient temperature (13.5 degrees C, 21 degrees C, 30 degrees C) and type of wound on healing of skin wounds were evaluated in common garter snakes (Thamnophis sirtalis). Linear unsutured incisions and circular excisional wounds were evaluated grossly and microscopically in three snakes held at each temperature at each of two, five and ten days after surgery. Linear sutured and unsutured incisions and circular and square excisional wounds were similarly evaluated three and six weeks after wound production in groups of six snakes held at each temperature. The rates of stabilization of wound margins, scab formation, migration and maturation of the regenerating epithelium, resolution of dermal inflammation, and fibroplasia varied directly with temperature. The inflammatory reaction to wounding was similar in character and intensity in snakes held at all three temperatures two days after surgery. Unsutured linear incisions, compared to sutured incisions, tended to have more rapid epithelial maturation and a less intense inflammatory response. Healing of square and circular excisional wounds was similar; contraction of round wounds was slightly more irregular and, at a few observations, dermal maturation was slower and inflammation more widespread. It was concluded that healing of skin wounds can be accelerated by holding reptiles at the upper end of their voluntary temperature range. Wounds, if possible, should be created along the axis of lines of skin tension. Suturing small incisional wounds may not be advantageous.

  3. Ambient Space and Ambient Sensation

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    The ambient is the aesthetic production of the sensation of being surrounded. As a concept, 'ambient' is mostly used in relation to the music genre 'ambient music' and Brian Eno's idea of environmental background music. However, the production of ambient sensations must be regarded as a central......, dehierarchization, ubiquity and the production of unfocused sensations in contrast to the conventional notion of the aesthetic experience as a focused contemplation of a stationary object....

  4. Influência da temperatura na solubilidade de beta-caroteno em solventes orgânicos à pressão ambiente Effect of temperature on the solubility of beta-carotene in organic solvents under ambient pressure

    Directory of Open Access Journals (Sweden)

    Marcus Vinícius Três

    2007-12-01

    Full Text Available O presente trabalho reporta dados experimentais de solubilidade em pressão ambiente de beta-caroteno em solventes orgânicos puros (etanol, acetona, acetato de etila e diclorometano e em misturas de tais solventes no intervalo de temperatura de 10 a 60 °C. Para este fim, adotou-se o método gravimétrico para a determinação da solubilidade, utilizando células encamisadas de equilíbrio. Os resultados mostraram que valores mais elevados de solubilidade são obtidos quando foram empregados solventes com parâmetros de solubilidade mais próximos daquele do soluto. Verificou-se que o aumento da temperatura, tanto para solventes puros, como para as misturas de solventes, acarretou num aumento da solubilidade do beta-caroteno para todas as condições experimentais. Observou-se ainda, que nas condições experimentais investigadas, não houve sinergismo significativo para as misturas de solventes quando comparadas aos valores de solubilidade obtidos para os solventes puros. O modelo UNIFAC se mostrou útil na previsão qualitativa dos resultados de solubilidade.This work reports experimental data of the solubility of beta-carotene in pure acetone, ethyl acetate, ethanol and dichloromethane and in mixtures of these organic solvents in the temperature range of 10 to 60 °C under ambient pressure. The gravimetric method was employed to determine the solubility, using glass equilibrium cells. The results showed that the best solvents were those having solubility parameter values close to that of the solute. It was found that raising the temperature caused the solute solubility values for both pure and solvent mixtures to increase under all the experimental conditions. Moreover, no synergetic effects were observed on the solubility of beta-carotene in solvent mixtures compared to pure solvents in the temperature range investigated. The UNIFAC model proved to be useful in predicting the solubility data.

  5. Room temperature magnetism of few-nanometers-thick Fe3O4(111) films on Pt(111) and Ru(0001) studied in ambient conditions

    International Nuclear Information System (INIS)

    Lewandowski, M.; Miłosz, Z.; Michalak, N.; Ranecki, R.; Sveklo, I.; Kurant, Z.; Maziewski, A.; Mielcarek, S.; Luciński, T.; Jurga, S.

    2015-01-01

    Few-nanometers-thick Fe 3 O 4 (111) films were epitaxially grown on Pt(111) and Ru(0001) single crystal supports by sequential iron deposition and oxidation in an ultra-high vacuum chamber. The growth of well-ordered magnetite films was confirmed by low energy electron diffraction. The films were covered with a protective Au layer and subjected to magnetic and structural studies in ambient conditions. Magnetic hysteresis loops, recorded using magneto-optical Kerr effect apparatus, confirmed magnetic ordering in both films at room temperature. The Kerr measurements indicated in-plane orientation of magnetization, which was supported by the lack of magnetic contrast in magnetic force microscopy images. Atomic force microscopy revealed significant differences in morphology of the films, tentatively attributed to different lattice mismatch with Pt(111) and Ru(0001) single crystal supports. - Highlights: • Few-nanometers-thick Fe 3 O 4 (111) films were grown on Pt(111) and Ru(0001). • Magnetic properties were studied using MOKE and AFM/MFM in ambient conditions. • The films exhibited in-plane magnetic ordering at room temperature. • Differences in magnetic properties were tentatively assigned to structural differences.

  6. Efficient and stable CH3NH3PbI3-x(SCN)x planar perovskite solar cells fabricated in ambient air with low-temperature process

    Science.gov (United States)

    Zhang, Zongbao; Zhou, Yang; Cai, Yangyang; Liu, Hui; Qin, Qiqi; Lu, Xubing; Gao, Xingsen; Shui, Lingling; Wu, Sujuan; Liu, Jun-Ming

    2018-02-01

    Planar perovskite solar cells (PSCs) based on CH3NH3PbI3-x(SCN)x (SCN: thiocyanate) active layer and low-temperature processed TiO2 films are fabricated by a sequential two-step method in ambient air. Here, alkali thiocyanates (NaSCN, KSCN) are added into Pb(SCN)2 precursor to improve the microstructure of CH3NH3PbI3-x(SCN)x perovskite layers and performance of the as-prepared PSCs. At the optimum concentrations of alkali thiocyanates as additives, the as-prepared NaSCN-modified and KSCN-modified PSCs demonstrate the efficiencies of 16.59% and 15.63% respectively, being much higher than 12.73% of the reference PSCs without additives. This improvement is primarily ascribed to the enhanced electron transport, reduced recombination rates and much improved microstructures with large grain size and low defect density at grain boundaries. Importantly, it is revealed that the modified PSCs at the optimized concentrations of alkali thiocyanates additives exhibit remarkably improved stability than the reference PSCs against humid circumstance, and a continuous exposure to humid air without encapsulation over 45 days only records about 5% degradation of the efficiency. These findings provide a facile approach to fabricate efficient and stable PSCs by low processing temperature in ambient air, both of which are highly preferred for future practical applications of PSCs.

  7. Neutral gas temperature maps of the pin-to-plate argon micro discharge into the ambient air

    International Nuclear Information System (INIS)

    Xu, S. F.; Zhong, X. X.; Majeed, Asif

    2015-01-01

    This study is designed to explore the two dimensional temperature maps of the atmospheric argon discharge consisting of pin-to-plane electrodes supplied by a high voltage DC source. After checking the stability of the micro discharge, the two dimensional image plane focused by a quartz lens was scanned by the fiber probe driven by a 3D Mobile Platform. The rotational and vibrational temperatures are calculated using nitrogen emissions collected by the high resolution spectrometer and high sensitive intensified charge coupled device. The rotational temperature varies from 1558.15 K to 2621.14 K and vibrational temperature varies from 3010.38 K to 3774.69 K, indicating a great temperature gradient due to small discharge size. The temperature maps show a lateral expansion and a sharp truncation in the radial direction. A double layers discharge is identified, where an arc discharge coats the glow discharge

  8. Development of Secondary Lithium-Sulfur Batteries for Low Temperature Environments

    Data.gov (United States)

    National Aeronautics and Space Administration — The next generation of space suits, landers, rovers, and spacecraft will require secondary batteries capable of storing larger amounts of energy. As missions venture...

  9. Time budgets of Snow Geese Chen caerulescens and Ross's Geese Chen rossii in mixed flocks: Implications of body size, ambient temperature and family associations

    Science.gov (United States)

    Jonsson, J.E.; Afton, A.D.

    2009-01-01

    Body size affects foraging and forage intake rates directly via energetic processes and indirectly through interactions with social status and social behaviour. Ambient temperature has a relatively greater effect on the energetics of smaller species, which also generally are more vulnerable to predator attacks than are larger species. We examined variability in an index of intake rates and an index of alertness in Lesser Snow Geese Chen caerulescens caerulescens and Ross's Geese Chen rossii wintering in southwest Louisiana. Specifically we examined variation in these response variables that could be attributed to species, age, family size and ambient temperature. We hypothesized that the smaller Ross's Geese would spend relatively more time feeding, exhibit relatively higher peck rates, spend more time alert or raise their heads up from feeding more frequently, and would respond to declining temperatures by increasing their proportion of time spent feeding. As predicted, we found that Ross's Geese spent more time feeding than did Snow Geese and had slightly higher peck rates than Snow Geese in one of two winters. Ross's Geese spent more time alert than did Snow Geese in one winter, but alert rates differed by family size, independent of species, in contrast to our prediction. In one winter, time spent foraging and walking was inversely related to average daily temperature, but both varied independently of species. Effects of age and family size on time budgets were generally independent of species and in accordance with previous studies. We conclude that body size is a key variable influencing time spent feeding in Ross's Geese, which may require a high time spent feeding at the expense of other activities. ?? 2008 The Authors.

  10. The Short-Term Effect of Ambient Temperature on Mortality in Wuhan, China: A Time-Series Study Using a Distributed Lag Non-Linear Model

    Directory of Open Access Journals (Sweden)

    Yunquan Zhang

    2016-07-01

    Full Text Available Less evidence concerning the association between ambient temperature and mortality is available in developing countries/regions, especially inland areas of China, and few previous studies have compared the predictive ability of different temperature indictors (minimum, mean, and maximum temperature on mortality. We assessed the effects of temperature on daily mortality from 2003 to 2010 in Jiang’an District of Wuhan, the largest city in central China. Quasi-Poisson generalized linear models combined with both non-threshold and double-threshold distributed lag non-linear models (DLNM were used to examine the associations between different temperature indictors and cause-specific mortality. We found a U-shaped relationship between temperature and mortality in Wuhan. Double-threshold DLNM with mean temperature performed best in predicting temperature-mortality relationship. Cold effect was delayed, whereas hot effect was acute, both of which lasted for several days. For cold effects over lag 0–21 days, a 1 °C decrease in mean temperature below the cold thresholds was associated with a 2.39% (95% CI: 1.71, 3.08 increase in non-accidental mortality, 3.65% (95% CI: 2.62, 4.69 increase in cardiovascular mortality, 3.87% (95% CI: 1.57, 6.22 increase in respiratory mortality, 3.13% (95% CI: 1.88, 4.38 increase in stroke mortality, and 21.57% (95% CI: 12.59, 31.26 increase in ischemic heart disease (IHD mortality. For hot effects over lag 0–7 days, a 1 °C increase in mean temperature above the hot thresholds was associated with a 25.18% (95% CI: 18.74, 31.96 increase in non-accidental mortality, 34.10% (95% CI: 25.63, 43.16 increase in cardiovascular mortality, 24.27% (95% CI: 7.55, 43.59 increase in respiratory mortality, 59.1% (95% CI: 41.81, 78.5 increase in stroke mortality, and 17.00% (95% CI: 7.91, 26.87 increase in IHD mortality. This study suggested that both low and high temperature were associated with increased mortality in Wuhan, and

  11. Thermal degradation of concrete in the temperature range from ambient to 315 degree C (600 degree F). Revision 10/96

    International Nuclear Information System (INIS)

    Kassir, M.K.; Bandyopadhyay, K.K.; Reich, M.

    1996-10-01

    This report is concerned with determining the effect of elevated temperatures on the behavior of concrete. Emphasis is placed on quantifying the degree of potential degradation of the physical properties of concrete in high-level waste storage tanks. The temperature elevation range of interest is from ambient to 315 C (600 F). The literature has been reviewed to examine the applicable experimental data and quantify the degradation in the concrete and reinforcing steel. Since many variables and test conditions control the results in the data base, upper and lower bounds of the degraded properties at temperatures applicable to the environments of the storage tanks are summarized and presented in explicit forms. For properties with large data bases, a normal logarithmic distribution of the data is assumed and a statistical analysis is carried out to find the mean and 84% values of the degraded property in the temperature range of interest. Such results are useful in assessing the effect of elevated temperatures on the structural behavior of the tanks. In addition, the results provide the technical basis for a parametric study that may be necessary to investigate the thermal aspects of the structural integrity of the tanks. 50 refs., 23 figs

  12. Online Estimation of Model Parameters and State of Charge of LiFePO4 Batteries Using a Novel Open-Circuit Voltage at Various Ambient Temperatures

    Directory of Open Access Journals (Sweden)

    Fei Feng

    2015-04-01

    Full Text Available This study describes an online estimation of the model parameters and state of charge (SOC of lithium iron phosphate batteries in electric vehicles. A widely used SOC estimator is based on the dynamic battery model with predeterminate parameters. However, model parameter variances that follow with their varied operation temperatures can result in errors in estimating battery SOC. To address this problem, a battery online parameter estimator is presented based on an equivalent circuit model using an adaptive joint extended Kalman filter algorithm. Simulations based on actual data are established to verify accuracy and stability in the regression of model parameters. Experiments are also performed to prove that the proposed estimator exhibits good reliability and adaptability under different loading profiles with various temperatures. In addition, open-circuit voltage (OCV is used to estimate SOC in the proposed algorithm. However, the OCV based on the proposed online identification includes a part of concentration polarization and hysteresis, which is defined as parametric identification-based OCV (OCVPI. Considering the temperature factor, a novel OCV–SOC relationship map is established by using OCVPI under various temperatures. Finally, a validating experiment is conducted based on the consecutive loading profiles. Results indicate that our method is effective and adaptable when a battery operates at different ambient temperatures.

  13. The effect of temperature on the secondary electron emission yield from single crystal and polycrystalline diamond surfaces

    International Nuclear Information System (INIS)

    Stacey, A.; Prawer, S.; Rubanov, S.; Ahkvlediani, R.; Michaelson, Sh.; Hoffman, A.

    2009-01-01

    The effect of temperature in the 293-473 K range, on the secondary electron emission (SEE) yield of single crystal and polycrystalline diamond film surfaces is reported. For the polycrystalline films the SEE yield was found to decay as function of electron irradiation dose while for the single crystal an increase occurs first, followed by a decrease. For both surfaces, the SEE yield increases significantly upon heating and obtained a nearly constant value with electron dose at 473 K. These effects are explained as due to the temperature dependence of the electron beam induced hydrogen desorption and surface band bending.

  14. Analysis of chiller units capacity for different heat loads considering variation of ambient air and cooling water temperature

    International Nuclear Information System (INIS)

    Coman, Aurelia Camelia; Tenescu, Mircea

    2010-01-01

    The paper purpose is to analyze the chiller units capacity to determine whether they can cope with high air and cooling water temperatures during summer time to remove heat loads imposed from Heating, Ventilation and Air Conditioning (HVAC) units in a CANDU 6 Nuclear Power Plant. The starting point is calculation of the overall heat transfer coefficient at the evaporator and condenser. They are used in heat balance equations of heat exchangers. A mathematical model was developed that simulates the refrigeration cycle to assess the response of chilled water system and its performance at different heat loads. In this analysis there were calculated values for inlet/outlet chilled water temperature and the refrigerant cycle thermodynamic parameters (condenser and evaporator pressure/temperature, refrigerant mass flowrate, refrigerant quality at the evaporator, refrigerant vapour superheated temperature at the compressor outlet, refrigerant subcooled temperature at the condenser outlet). To find the adequate functioning parameters of the installation, the MathCAD 13 software was used in all cases analyzed. The behaviour of the chiller units was investigated by examining the variation of three basic parameters, namely: - cooling water (river water) temperature; - air temperature; - heat load. The simultaneous variation of these three independent parameters allows to identify the actual chillers unit operating point (including chiller trip). (authors)

  15. Interactive Matching between the Temperature Profile and Secondary Reactions of Oil Shale Pyrolysis

    DEFF Research Database (Denmark)

    Zhang, Yu; Han, Zhennan; Wu, Hao

    2016-01-01

    This article investigates the effect of the reactor temperature profile on the distribution and characteristics of the products from fixed-bed pyrolysis of oil shale. Experiments were performed in a one-stage fixed-bed reactor and in a two-stage fixed-bed reactor. In the one-stage reactor......, the shale oil yield reached 7.40 wt % with a reactor temperature profile from 900 to 550 degrees C and decreased to 2.23 wt % with the reverse temperature profile. The effect of the temperature profile was investigated further in the two-stage fixed-bed reactor combining a pyrolysis stage operating at 550...... degrees C and a shale char bed operating at different temperatures. At low temperatures (550 degrees C), severe cracking occurred, converting both heavy and light oil to carbon and gas. The desirably matched reactor temperature profile for high oil yield is discussed via analysis of the tendency...

  16. The effects of ambient temperature and heatwaves on daily Campylobacter cases in Adelaide, Australia, 1990-2012.

    Science.gov (United States)

    Milazzo, A; Giles, L C; Zhang, Y; Koehler, A P; Hiller, J E; Bi, P

    2017-09-01

    Campylobacter spp. is a commonly reported food-borne disease with major consequences for morbidity. In conjunction with predicted increases in temperature, proliferation in the survival of microorganisms in hotter environments is expected. This is likely to lead, in turn, to an increase in contamination of food and water and a rise in numbers of cases of infectious gastroenteritis. This study assessed the relationship of Campylobacter spp. with temperature and heatwaves, in Adelaide, South Australia. We estimated the effect of (i) maximum temperature and (ii) heatwaves on daily Campylobacter cases during the warm seasons (1 October to 31 March) from 1990 to 2012 using Poisson regression models. There was no evidence of a substantive effect of maximum temperature per 1 °C rise (incidence rate ratio (IRR) 0·995, 95% confidence interval (95% CI) 0·993-0·997) nor heatwaves (IRR 0·906, 95% CI 0·800-1·026) on Campylobacter cases. In relation to heatwave intensity, which is the daily maximum temperature during a heatwave, notifications decreased by 19% within a temperature range of 39-40·9 °C (IRR 0·811, 95% CI 0·692-0·952). We found little evidence of an increase in risk and lack of association between Campylobacter cases and temperature or heatwaves in the warm seasons. Heatwave intensity may play a role in that notifications decreased with higher temperatures. Further examination of the role of behavioural and environmental factors in an effort to reduce the risk of increased Campylobacter cases is warranted.

  17. Influence of deuterium content on tensile behavior of Zr-2.5Nb pressure tube material in the temperature range of ambient to 300 degC

    International Nuclear Information System (INIS)

    Bind, A.K.; Singh, R.N.; Chakravartty, J.K.; Dhandharia, Priyesh; Ghosh, Agnish; More, Nitin S.; Chhatre, A.G.; Vijayakumar, S.

    2011-08-01

    Tensile properties of autoclaved zirconium-2.5 wt. % niobium pressure tube material were evaluated by uniaxial tension tests at temperatures between 25 and 300 degC and under strain-rates of 1.075 x 10 -4 /s. Six number of Zr-2.5Nb alloy pressure tube spools of length 130 mm were obtained from pressure tube number 19-2557-2. Five spools were polished with abrasive paper to remove the oxide layer. These spools were gaseously charged with controlled amount of deuterium. The target deuterium concentrations were 25, 50, 75, 100 and 200 wppm of hydrogen equivalent. Ten samples were machined by EDM wire cutting from every spool. The tensile specimen axis was oriented along longitudinal direction of the tube. Metallographic examination of the deuterium charged samples suggested that the deuterides were predominantly circumferential deuterides. Analysis of tensile results showed that both yield and ultimate tensile strengths of this alloy decreased monotonically with increasing test temperatures. The tensile ductility decreased marginally with increase in test temperature from ambient to 300 degC. It was also observed that both strength and ductility appear to be unaffected by deuterium content at all temperatures, thereby suggesting that at least up to 200 wppm (Heq.) of deuterium tensile properties are not influenced by deuterium. (author)

  18. Use of ethyl lactate to extract bioactive compounds from Cytisus scoparius: Comparison of pressurized liquid extraction and medium scale ambient temperature systems.

    Science.gov (United States)

    Lores, Marta; Pájaro, Marta; Álvarez-Casas, Marta; Domínguez, Jorge; García-Jares, Carmen

    2015-08-01

    An important trend in the extraction of chemical compounds is the application of new environmentally friendly, food grade solvents. Ethyl lactate (ethyl 2-hydroxypropanoate), produced by fermentation of carbohydrates, is miscible with both hydrophilic and hydrophobic compounds being a potentially good solvent for bioactive compounds. Despite its relatively wide use as a general solvent, the utilization of ethyl lactate as an extraction solvent has only recently been considered. Here, we evaluate the possible use of ethyl lactate to extract phenolic compounds from wild plants belonging to Cytisus scoparius, and we compare the characteristics of the extracts obtained by Pressurized Solvent Extraction (the total phenolics content, the antioxidant activity and the concentration of the major polyphenols) with those of other extracts obtained with methanol. In order to explore the industrial production of the ethyl lactate Cytisus extract, we also evaluate medium scale ambient temperature setups. The whole plant and the different parts (flowers, branches, and seed pods) were evaluated separately as potential sources of polyphenols. All extracts were analyzed by LC-MS/MS for accurate identification of the major polyphenols. Similar phenolic profiles were obtained when using ethyl lactate or methanol. The main bioactives found in the Cytisus extract were the non-flavonoid phenolic compounds caffeic and protocatechuic acids and 3,4-dihydroxybenzaldehyde; the flavonoids rutin, kaempferol and quercetin; the flavones chrysin, orientin and apigenin; and the alkaloid lupanine. Regarding the comparison of the extraction systems, although the performance of the PLE was much better than that of the ambient-temperature columns, the energy consumption was also much higher. Ethyl lactate has resulted an efficient extraction solvent for polyphenols from C. scoparius, yielding extracts with high levels of plant phenolics and antioxidant activity. The antimicrobial activity of these

  19. Changes in ambient temperature and oxygenation during the proestrus do not affect duration, regularity and repeatability of the estrus cycle in female rats.

    Directory of Open Access Journals (Sweden)

    Grazyna Wójcik

    2009-12-01

    Full Text Available There are a lot of factors affecting the release of hormones from the anterior part of pituitary gland and their interactions with other parts of the endocrine, nervous and immune systems. The special significance of the proestrus phase of the estrous cycle of the rat, during which LH and FSH levels increase, followed by ovulation is known. The short length of the estrous cycle and the well recognized sequence of vaginal lavage cytology make it useful for investigating the influence of a stressful environment on the reproductive function. Short duration and mild changes in environmental conditions is considered as a factor analogous to psychological stress. The study was undertaken to determine the effects of a short duration change in the ambient temperature and oxygenation (30 minutes on the proestrus phase of reproductive cycle and on the repeatability and regularity of phases of the reproductive cycle of Wistar strain rats. The animals were kept under standard conditions and had food and water available ad libitum. The climatic chamber with automatically adjustable and monitored internal parameters (temperature, oxygenation, humidity was used to develop stress conditions. An estimation of the vaginal lavage using the microscope was done to determine the estrous cycle. The animals were divided into 6 groups. On the day of experiment: the control group (CG stayed in the climatic chamber for 30 minutes (ambient temperature 21 degrees C, normoxia - 21% O(2, the five test groups (TG - I - V remained in the climatic chamber for 30 minutes, in the established environmental conditions (I - 21 degrees C, 10% O(2; II - 10 degrees C, 21% O(2; III - 10 degrees C, 10% O(2; IV - 35 degrees C, 21% O(2; V - 35 degrees C, 10% O(2. During the following days after the experiment, a microscopic estimation of vaginal lavage was collected over again. There were no changes of duration and sequence of the present estrous cycle and repeatability of the next cycles

  20. The impact of ambient operating room temperature on neonatal and maternal hypothermia and associated morbidities: a randomized controlled trial.

    Science.gov (United States)

    Duryea, Elaine L; Nelson, David B; Wyckoff, Myra H; Grant, Erica N; Tao, Weike; Sadana, Neeti; Chalak, Lina F; McIntire, Donald D; Leveno, Kenneth J

    2016-04-01

    Neonatal hypothermia is common at the time of cesarean delivery and has been associated with a constellation of morbidities in addition to increased neonatal mortality. Additionally, maternal hypothermia is often uncomfortable for the surgical patient and has been associated with intraoperative and postoperative complications. Various methods to decrease the rates of neonatal and maternal hypothermia have been examined and found to have varying levels of success. We sought to determine whether an increase in operating room temperature at cesarean delivery results in a decrease in the rate of neonatal hypothermia and associated morbidities. In this single-center randomized trial, operating room temperatures were adjusted weekly according to a cluster randomization schedule to either 20°C (67°F), which was the standard at our institution, or 23°C (73°F), which was the maximum temperature allowable per hospital policy. Neonatal hypothermia was defined as core body temperature temperature was 23°C (5%); in contrast such hypothermia occurred in 19% of the standard management group, P temperature in the operating room immediately following delivery and stabilization was also higher in the study group, 37.1 ± 0.6°C vs 36.9 ± 0.6°C, P temperature >38.0°C or 100.4°F) on arrival to the admitting unit was uncommon and did not differ between the study groups. Maternal temperature on arrival to the operating room was not different between the 2 groups, however by delivery it was significantly lower in the standard management group, 36.2 ± 0.6°C vs 36.4 ± 0.6°C, P temperature on arrival to the postoperative care area was lower in the standard management group, 36.1 ± 0.6°C vs 36.2 ± 0.6°C, P temperature at the time of cesarean reduces the rate of neonatal and maternal hypothermia. We did not detect a decrease in neonatal morbidity, but the power to detect a small change in these outcomes was limited. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Non-Linear Association between Exposure to Ambient Temperature and Children's Hand-Foot-and-Mouth Disease in Beijing, China.

    Directory of Open Access Journals (Sweden)

    Meimei Xu

    Full Text Available Hand, foot and mouth disease (HFMD was listed as a notifiable communicable disease in 2008 and is an emerging public health problem in China, especially for children. However, few data are available on the risk assessment of the potential reasons for HFMD in Beijing. This study examined the association of temperature with the incidence of children's HFMD in Beijing at the daily scale for the first time.A newly developed case-crossover design with a distributed lag nonlinear model (DLNM was used to assess the delayed and cumulative associations of daily temperature with gender- and age-specific HFMD in Beijing, China, during 2010-2012. Relative humidity, day of the week, public holiday, season and long-term trends were controlled in the model.Among the total of 113,475 cases, the ratio between males and females was 1.52:1. HFMD was more prevalent in May-July. The temperature-HFMD relationships were non-linear in most age groups except for children aged 6-15 years, with a peak at 25.0~27.5°C. The high-temperature risks were greater, appeared earlier and lasted longer than the low-temperature risks. The relative risks for female children and those aged 6-15 years were higher than those among other groups.Rising temperatures increased the incidence of children's HFMD, with the largest association at 25.0~27.5°C. Females and children aged 6-15 years were more vulnerable to changes in temperature with regard to the transmission of HFMD than males and other age groups, respectively. Further studies are warranted to confirm these findings in other populations.

  2. Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains

    DEFF Research Database (Denmark)

    Nielsen, Birte Lindstrøm

    2012-01-01

    in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted......Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity...... and weighing more, and with a less efficient feed conversion than HH chickens, with HC birds intermediate. A similar effect was found for Ross 208 only for feed intake from 27 to 41 days of age. Ross 208 chickens distributed themselves in the pen with a preference for cooler areas in the hottest ambient...

  3. The effects of fabric for sleepwear and bedding on sleep at ambient temperatures of 17°C and 22°C

    Directory of Open Access Journals (Sweden)

    Shin M

    2016-04-01

    Full Text Available Mirim Shin,1 Mark Halaki,1 Paul Swan,2 Angus Ireland,2 Chin Moi Chow1 1Exercise, Health and Performance Research Group, Faculty of Health Sciences, The University of Sydney, Lidcombe, 2Australian Wool Innovation Limited, The Woolmark Company, Sydney, NSW, Australia Abstract: The fibers used in clothing and bedding have different thermal properties. This study aimed to investigate the influences of textile fabrics on sleep under different ambient temperature (Ta conditions. Seventeen healthy young participants (ten males underwent nine nights of polysomnography testing including an adaptation night. Participants were randomized to each of the three binary factors: sleepwear (cotton vs wool, bedding (polyester vs wool, and Ta (17°C vs 22°C with relative humidity set at 60%. Skin temperature (Tsk and core temperature (Tc were monitored throughout the sleep period. Sleep onset latency (SOL was significantly shortened when sleeping in wool with trends of increased total sleep time and sleep efficiency compared to cotton sleepwear. At 17°C, the proportion of sleep stages 1 (%N1 and 3 (%N3 and rapid eye movement sleep was higher, but %N2 was lower than at 22°C. Interaction effects (sleepwear × Ta showed a significantly shorter SOL for wool than cotton at 17°C but lower %N3 for wool than cotton at 22°C. A significantly lower %N2 but higher %N3 was observed for wool at 17°C than at 22°C. There was no bedding effect on sleep. Several temperature variables predicted the sleep findings in a stepwise multiple regression analysis and explained 67.8% of the variance in SOL and to a lesser degree the %N2 and %N3. These findings suggest that sleepwear played a contributory role to sleep outcomes and participants slept better at 17°C than at 22°C.Keywords: cotton, polyester, wool, polysomnography, skin temperature, core body temperature

  4. Effect of Primary Recrystallized Microstructure and Nitriding on Secondary Recrystallization in Grain Oriented Silicon Steel by Low Temperature Slab Reheating

    Directory of Open Access Journals (Sweden)

    LIU Gong-tao

    2018-01-01

    Full Text Available Different primary recrystallized grain sizes were obtained by controlling decarburization process in grain oriented silicon steel produced by low temperature slab reheating technique. The effect of primary grain size on secondary recrystallization and magnetic properties was studied. The appropriate nitrogen content after nitriding was explored in case of very large primary grain size, and the effect of {411}〈148〉 primary recrystallized texture on the abnormal growth behavior was discussed. The results show that an increase in average primary grain size from 10μm to 15μm leads to an increase of secondary recrystallization temperature and a sharper Goss texture with higher magnetic permeability, in the condition of a very large average primary grain size of 28μm, the suitable amount of nitrogen increases to about 6×10-4. The {411}〈148〉 oriented grains in primary recrystallized microstructure can easily grow into larger sizes due to their size advantage, and thus hinder the abnormal growth of secondary grains, moreover, the hindering effect is more pronounced in the abnormal growth of Brass-oriented grains due to their misorientation with low migration rate other than Goss grains.

  5. Influence of ambient oxygenation and temperature on metabolic scope and scope for heart rate in the common sole Solea solea

    OpenAIRE

    Lefrancois, Christelle; Claireaux, Guy

    2003-01-01

    The objective of this study was to quantify the constraints exerted by temperature and oxygenation on both metabolic scope and scope for heart rate of the common sole Solea solea. We exposed sole to a large range of temperature and oxygenation conditions and a modelling procedure was implemented to describe metabolic and cardiac responses. Standard metabolic rate (SMR) rose exponentially from 4 to 24degreesC, whereas active metabolic rate (AMR) increased from 55.4 to 159.2 mgO(2) kg(-1) h(-1)...

  6. Det ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Om begrebet "det ambiente", der beskriver, hvad der sker, når vi fornemmer baggrundsmusikkens diskrete beats, betragter udsigten gennem panoramavinduet eller tager 3D-brillerne på og læner os tilbage i biografsædet. Bogen analyserer, hvorfan ambiente oplevelser skabes, og hvilke konsekvenser det...

  7. Ambient Sensors

    NARCIS (Netherlands)

    Börner, Dirk; Specht, Marcus

    2014-01-01

    This software sketches comprise two custom-built ambient sensors, i.e. a noise and a movement sensor. Both sensors measure an ambient value and process the values to a color gradient (green > yellow > red). The sensors were built using the Processing 1.5.1 development environment. Available under

  8. Cationic Protic Imidazolylidene NHC Complexes of Cp*IrCl+ and Cp*RhCl+ with a Pyridyl Tether Formed at Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Douglas B. Grotjahn

    2018-02-01

    Full Text Available Protic NHC (PNHC complexes with N1H, N2-alkyl/aryl imidazolylidene ligands are relatively rare, and routes for their synthesis differ from what is used to make non-protic analogs. Prior work from our group and others showed that in the presence of a tethering ligand (phosphine or in one case, pyridine, CpM and Cp*M (M = Ir, Ru PNHC complexes could be made by heating. Here, we find that the use of ionizing agents to activate [Cp*MIIICl(μ-Cl]2 (M = Ir, Rh allows for what we believe is unprecedented ambient temperature formation of PNHC complexes from neutral imidazoles; the product complexes are able to perform transfer hydrogenation.

  9. High-T(sub c) Superconductor-Normal-Superconductor Junctions with Polyimide-Passivated Ambient Temperature Edge Formation

    Science.gov (United States)

    Barner, J. B.; Kleinsasser, A. W.; Hunt, B. D.

    1996-01-01

    The ability to controllably fabricate High-Temperature Superconductor (HTS) S-Normal-S (SNS) Josephson Juntions (JJ's) enhances the possibilities fro many applications, including digital circuits, SQUID's, and mixers. A wide variety of approaches to fabricating SNS-like junctions has been tried and analyzed in terms of proximity effect behavior.

  10. Ambient temperature aqueous synthesis of ultrasmall copper doped ceria nanocrystals for the water gas shift and carbon monoxide oxidation reactions

    Energy Technology Data Exchange (ETDEWEB)

    Curran, Christopher D. [Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem; USA; Lu, Li [Department of Materials Science and Engineering; Lehigh University; Bethlehem; USA; Kiely, Christopher J. [Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem; USA; Department of Materials Science and Engineering; McIntosh, Steven [Department of Chemical and Biomolecular Engineering; Lehigh University; Bethlehem; USA

    2018-01-01

    Ultra-small CuxCe1-xO2-δnanocrystals were prepared through a room temperature, aqueous synthesis method, achieving high copper doping and low water gas shift activation energy.

  11. Modulation of ambient temperature promotes inflammation and initiates atherosclerosis in wild type C57BL/6 mice

    Directory of Open Access Journals (Sweden)

    Daniel A. Giles

    2016-11-01

    Conclusions: In sum, our novel data in WT C57Bl/6 mice suggest that modulation of a single environmental variable, temperature, dramatically alters mouse physiology, metabolism, and inflammation, allowing for an improved mouse model of atherosclerosis. Thus, thermoneutral housing of mice shows promise in yielding a better understanding of the cellular and molecular pathways underlying the pathogenesis of diverse diseases.

  12. Cyclic deformation of NI/sub 3/(Al,Nb) single crystals at ambient and elevated temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Bonda, N.R.

    1985-01-01

    Cyclic tests were performed on Ni/sub 3/(Al,Nb) (..gamma..' phase) single crystals by using a servo-hydraulic machine under fully reversed plastic strain control at a frequency of 0.1-0.2 Hz at room temperature, 400/sup 0/C and 700/sup 0/C. Since the monotonic behavior is orientation dependent, three orientations were studied. Asymmetry in tensile and compressive stresses was observed in the cyclic hardening curves of specimens tested at these temperatures and they were discussed with regard to the model suggested by Paider et al for monotonic behavior. The stress levels in the cyclic stress-strain curves (CSSC) at room temperature depended on orientation and cyclic history. No CSSCs were established at 400/sup 0/C and 700/sup 0/C. The deformation in cyclic tests at small plastic strain amplitudes was found to be different from that in monotonic tests in the microplastic regions in which the deformation is believed to be carried by a small density of edge dislocations. But in cyclic deformation, to and from motion of dislocations trap the edge dislocations into dipoles and therefore screw dislocations will be forced to participate in the deformation. Cracks on the surfaces of specimens tested at room temperature and 400/sup 0/C were found to be of stage I type, whereas at 700/sup 0/C, they were of stage II type.

  13. Periodic usage of low-protein methionine-fortified diets in broiler chickens under high ambient temperature conditions: effects on performance, slaughter traits, leukocyte profiles and antibody response

    Science.gov (United States)

    Ghasemi, Hossein Ali; Ghasemi, Rohollah; Torki, Mehran

    2014-09-01

    This study was performed to evaluate the effects of adding methionine supplements to low-protein diets and subsequent re-feeding with a normal diet on the productive performance, slaughter parameters, leukocyte profiles and antibody response in broiler chickens reared under heat stress conditions. During the whole experimental period (6-49 days), the birds were raised in battery cages located in high ambient temperature in an open-sided housing system. A total of 360 6-day-old male chickens were divided into six treatments in six replicates with ten chicks each. Six isoenergetic diets, with similar total sulfur amino acids levels, were formulated to provide 100 and 100 (control), 85 and 100 (85S), 70 and 100 (70S), 85 and 85 (85SG), 70 and 85 (70S85G), and 70 and 70 % (70SG) of National Research Council recommended levels for crude protein during the starter (6-21 day) and grower (22-42 day) periods, respectively. Subsequently, all groups received a diet containing the same nutrients during the finisher period (43-49 day). The results showed that, under heat stress conditions, average daily gain and feed conversion ratio and performance index from day 6 to 49, breast and thigh yields and antibody titer against Newcastle disease in the birds fed diets 85S, 70S and 85SG were similar to those of birds fed control diet, whereas feeding diets 70S85G and 70SG significantly decreased the values of above-mentioned parameters. Additionally, diets 85S, 70S and 85SG significantly decreased mortality rate and heterophil:lymphocyte ratio compared with the control diet. In conclusion, the results indicate that supplementation of methionine to diets 85S, 70S and 85SG, and then re-feeding with a conventional diet is an effective tool to maintain productive performance and to improve health indices and heat resistance in broilers under high ambient temperature conditions.

  14. The Combined Effect of High Ambient Temperature and Antihypertensive Treatment on Renal Function in Hospitalized Elderly Patients.

    Directory of Open Access Journals (Sweden)

    Iftach Sagy

    Full Text Available The aging kidney manifests structural, functional as well as pharmacological changes, rendering elderly patients more susceptible to adverse environmental influences on their health, dehydration in particular.Higher temperature is associated with renal function impairment in patients 65 years and older who routinely take thiazide and/or ACE-inhibitors/ARBs.We obtained health data of patients older than 65 who were admitted to a large tertiary center during the years 2006-2011, with a previous diagnosis of hypertension, and treated with thiazide, ACE-inhibitors/ARBs or both. We collected environmental data of daily temperature, available from collaborative public and governmental institutions. In order to estimate the effect of daily temperature on renal function we performed linear mixed models, separately for each treatment group and creatinine change during hospital admission.We identified 26,286 admissions for 14, 268 patients with a mean age of 75.6 (±6.9 years, of whom 53.6% were men. Increment in daily temperature on admission of 5°C had significant effect on creatinine increase in the no treatment (baseline creatinine adjusted 0.824 mg/dL, % change 1.212, % change 95% C.I 0.082-2.354 and dual treatment groups (baseline creatinine adjusted 1.032mg/dL, % change 3.440, % change 95% C.I 1.227-5.700. Sub-analysis stratified by advanced age, chronic kidney disease and primary diagnosis on hospital admission, revealed a significant association within patients admitted due to acute infection and treated with dual therapy.Whereas previous studies analyzed sporadic climate effects during heat waves and/or excluded older population taking anti-hypertensive medications, the present study is novel by showing a durable association of temperature and decreased renal function specifically in elderly patients taking anti-hypertensive medications.

  15. Barium isotope fractionation during experimental formation of the double carbonate BaMn[CO3](2) at ambient temperature.

    Science.gov (United States)

    Böttcher, Michael E; Geprägs, Patrizia; Neubert, Nadja; von Allmen, Katja; Pretet, Chloé; Samankassou, Elias; Nägler, Thomas F

    2012-09-01

    In this study, we present the first experimental results for stable barium (Ba) isotope ((137)Ba/(134)Ba) fractionation during low-temperature formation of the anhydrous double carbonate BaMn[CO(3)](2). This investigation is part of an ongoing work on Ba fractionation in the natural barium cycle. Precipitation at a temperature of 21±1°C leads to an enrichment of the lighter Ba isotope described by an enrichment factor of-0.11±0.06‰ in the double carbonate than in an aqueous barium-manganese(II) chloride/sodium bicarbonate solution, which is within the range of previous reports for synthetic pure BaCO (3) (witherite) formation.

  16. Room temperature reaction of oxygen with gold: an in situ ambient-pressure X-ray photoelectron spectroscopy investigation

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Peng; Porsgaard, Soeren; Borondics, Ferenc; Kober, Mariana; Caballero, Alfonso; Bluhm, Hendrik; Besenbacher, Flemming; Salmeron, Miquel

    2010-02-01

    Gold is commonly regarded as the most inert element.1 However, the discovery of the exceptional catalytic properties of gold nanoparticles (NPs) for low temperature CO oxidation2 initiated great interest due to its promising applications and spawned a large number of studies devoted to the understanding of the reaction mechanism.3-6 Nevertheless, no consistent and conclusive picture has arisen.7-13

  17. Tensile deformation behaviors of Zircaloy-4 alloy at ambient and elevated temperatures: In situ neutron diffraction and simulation study

    International Nuclear Information System (INIS)

    Li, Hongjia; Sun, Guangai; Woo, Wanchuck; Gong, Jian; Chen, Bo; Wang, Yandong; Fu, Yong Qing; Huang, Chaoqiang; Xie, Lei; Peng, Shuming

    2014-01-01

    Tensile stress–strain relationship of a rolled Zircaloy-4 (Zr-4) plate was examined in situ using a neutron diffraction method at room temperature (RT, 25 °C) and an elevated temperature (250 °C). Variations of lattice strains were obtained as a function of macroscopic bulk strains along prismatic (101 ¯ 0), basal (0 0 0 2) and pyramidal (101 ¯ 1) planes in the hexagonal close-packed structure of the Zr-4. The mechanisms of strain responses in these three major planes were simulated using elastic–plastic self-consistent (EPSC) model based on Hill–Hutchinson method, thus the inter-granular stresses and deformation systems of each individual grain under loading were obtained. Results show that there is a good agreement between the EPSC modeling and neutron diffraction measurements in terms of macroscopic stress–strain relationship and lattice strain evolutions of the planes at RT. However, there is a slight discrepancy in the lattice strains obtained from the EPSC modeling and neutron diffraction when the specimen was deformed at 250 °C. Analysis of grain structure and texture obtained using electron back-scattered diffraction suggests that dynamic recovery process is significant during the tensile deformation at the elevated temperature, which was not considered in the simulation

  18. Det Ambiente

    DEFF Research Database (Denmark)

    Schmidt, Ulrik

    Det ambiente er iscenesættelsen af en karakteristisk sanseoplevelse, der er kendetegnet ved fornemmelsen af at være omgivet. I dag bliver begrebet om det ambiente mest anvendt i forbindelse med musikgenren ’ambient musik’. Det ambiente er dog ikke essentielt knyttet til det musikalske, men må...... forstås som et betydeligt bredere fænomen i den moderne æstetiske kultur, der spiller en væsentlig rolle i oplevelsen af moderne transportformer, arkitektur, film, lydkunst, installationskunst og digitale multimedieiscenesættelser. En forståelse af det ambiente er derfor centralt for forståelsen af en...... moderne æstetiseret oplevelseskultur i almindelighed. Da det ambiente ikke hidtil har været gjort til genstand for en mere indgående teoretisk behandling, er der dog stor usikkerhed omkring, hvad fænomenet overhovedet indebærer. Hovedformålet med Det ambiente – Sansning, medialisering, omgivelse er derfor...

  19. Modificações nas atividades da poligalacturonase e pectinametilesterase em morangos armazenados a temperatura ambiente Modifications in the activities of poligalacturonase and pectinametilesterase in stored strawberries the ambient temperature

    Directory of Open Access Journals (Sweden)

    Polyanna Alves Silva

    2009-01-01

    Full Text Available Objetivou-se, neste trabalho, avaliar as modificações da poligalacturonase (PG e da pectinametilesterase (PME em morangos cultivados na região de Lavras, MG, e armazenados em temperatura ambiente. Foram utilizados morangos das cultivares 'Oso-grande', 'Toyorrinho' e 'Tudla'. Utilizou-se o delineamento inteiramente casualizado com 4 repetições, sendo os tratamentos arranjados em esquema fatorial (3X2, sendo 3 cultivares e 2 dias de análises (0 e 5 dias. A parcela experimental foi constituída por 10 frutos. Durante o armazenamento houve uma diminuição nos teores de pectina total e um aumento nos de pectina solúvel em todas as variedades analisadas. A atividade da PG e PME aumentaram com o período de armazenamento, independente da cultivar.The objective of this research was to evaluate the modifications of the polygalacturonase (PG and the pectinmethilesterase (PME in strawberries cultivated in the region of Lavras, MG, and stored at room temperature. Strawberries of the research were used for plantation of 'Oso-grande', 'Toyorrinho' and 'Tudla'. The entirely randomized design with 4 replicates was used, being the treatments arranged in factorial (3x2, being 3 plantations and 2 days of analyses (0 and 5 days. The experimental parcel was consisted by 10 fruits. During the storage there was a reduction in the levels of total pectin and an increase in the ones of soluble pectin in all the analyzed varieties. With the period of storage the PG and PME activity grew, independent of the cultivar.

  20. Performance of a pilot scale microbial electrolysis cell fed on domestic wastewater at ambient temperatures for a 12 month period.

    Science.gov (United States)

    Heidrich, Elizabeth S; Edwards, Stephen R; Dolfing, Jan; Cotterill, Sarah E; Curtis, Thomas P

    2014-12-01

    A 100-L microbial electrolysis cell (MEC) was operated for a 12-month period fed on raw domestic wastewater at temperatures ranging from 1°C to 22°C, producing an average of 0.6 L/day of hydrogen. Gas production was continuous though decreased with time. An average 48.7% of the electrical energy input was recovered, with a Coulombic efficiency of 41.2%. COD removal was inconsistent and below the standards required. Limitations to the cell design, in particular the poor pumping system and large overpotential account for many of the problems. However these are surmountable hurdles that can be addressed in future cycles of pilot scale research. This research has established that the biological process of an MEC will to work at low temperatures with real wastewater for prolonged periods. Testing and demonstrating the robustness and durability of bioelectrochemical systems far beyond that in any previous study, the prospects for developing MEC at full scale are enhanced. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  1. Influence of substrate metal alloy type on the properties of hydroxyapatite coatings deposited using a novel ambient temperature deposition technique.

    Science.gov (United States)

    Barry, J N; Cowley, A; McNally, P J; Dowling, D P

    2014-03-01

    Hydroxyapatite (HA) coatings are applied widely to enhance the level of osteointegration onto orthopedic implants. Atmospheric plasma spray (APS) is typically used for the deposition of these coatings; however, HA crystalline changes regularly occur during this high-thermal process. This article reports on the evaluation of a novel low-temperature (alloy substrates. This study addresses the suitability of the CoBlast technique for the deposition of HA coatings on a number of alternative metal alloys utilized in the fabrication of orthopedic devices. In addition to titanium grade 5, both cobalt chromium and stainless steel 316 were investigated. In this study, HA coatings were deposited using both the CoBlast and the plasma sprayed techniques, and the resultant HA coating and substrate properties were evaluated and compared. The CoBlast-deposited HA coatings were found to present similar surface morphologies, interfacial properties, and composition irrespective of the substrate alloy type. Coating thickness however displayed some variation with the substrate alloy, ranging from 2.0 to 3.0 μm. This perhaps is associated with the electronegativity of the metal alloys. The APS-treated samples exhibited evidence of both coating, and significantly, substrate phase alterations for two metal alloys; titanium grade 5 and cobalt chrome. Conversely, the CoBlast-processed samples exhibited no phase changes in the substrates after depositions. The APS alterations were attributed to the brief, but high-intensity temperatures experienced during processing. Copyright © 2013 Wiley Periodicals, Inc.

  2. Influence of ageing on the quasistatic fracture toughness of an SS 316(N) weld at ambient and elevated temperatures

    International Nuclear Information System (INIS)

    Sasikala, G.; Ray, S.K.

    2011-01-01

    The leak before break analysis of SS 316L(N) components of the prototype fast breeder reactor requires the elastic plastic fracture toughness parameter J for 0.2 mm crack extension, J 0.2 , especially for the welds, at the operating temperatures. The J-R curves for the welds produced using the consumable developed by Indira Gandhi Centre for Atomic Research, were determined in the as-welded condition as well as after thermal ageing (923 K/4200 h) conditions at 298 K and 643 K, using unloading compliance method for 298 K and normalization method for 643 K. The aged material exhibited pop-in crack extensions of magnitudes that, according to ASTM E1820 standard, could be ignored for multi-specimen data analysis for determining J 0.2 . Therefore, for this condition, J nom -Δa curves were established using the multiple specimen method and also single specimen normalization method; for the latter, a modification earlier developed by the authors for accounting for small pop-in crack extensions was used. The value of J 0.2 from both methods showed excellent reproducibility. Ageing is seen to reduce the toughness of this material considerably at both the testing temperatures.

  3. Effects of ambient temperature on egg and larval development of the invasive emerald ash borer (Coleoptera: Buprestidae): implications for laboratory rearing.

    Science.gov (United States)

    Duan, Jian J; Watt, Tim; Taylor, Phil; Larson, Kristi; Lelito, Jonathan P

    2013-10-01

    The emerald ash borer, Agrilus planipennis Fairmaire, an invasive beetle from Asia causing large scale ash (Fraxinus) mortality in North America, has been extremely difficult to rear in the laboratory because of its long life cycle and cryptic nature of immature stages. This lack of effective laboratory-rearing methods has not only hindered research into its biology and ecology, but also mass production of natural enemies for biological control of this invasive pest. Using sticks from the alternate host plant, Fraxinus uhdei (Wenzig) Lingelsh, we characterized the stage-specific development time and growth rate of both emerald ash borer eggs and larvae at different constant temperatures (12-35 degrees C) for the purpose of developing effective laboratory-rearing methods. Results from our study showed that the median time for egg hatching decreased from 20 d at 20 degrees C to 7 d at 35 degrees C, while no emerald ash borer eggs hatched at 12 degrees C. The developmental time for 50% of emerald ash borer larvae advancing to third, fourth, and J-larval stages at 20 degrees C were 8.3, 9.1, and 12.3 wk, respectively, approximately two times longer than at 30 degrees C for the corresponding instars or stages. In contrast to 30 degrees C, however, the development times of emerald ash borer larvae advancing to later instars (from oviposition) were significantly increased at 35 degrees C, indicating adverse effects of this high temperature. The optimal range of ambient temperature to rear emerald ash borer larvae should be between 25-30 degrees C; however, faster rate of egg and larval development should be expected as temperature increases within this range.

  4. The Effect of Seasonal Ambient Temperatures on Fire-Stimulated Germination of Species with Physiological Dormancy: A Case Study Using Boronia (Rutaceae)

    Science.gov (United States)

    Auld, Tony D.; Keith, David A.; Hui, Francis K. C.; Ooi, Mark K. J.

    2016-01-01

    Dormancy and germination requirements determine the timing and magnitude of seedling emergence, with important consequences for seedling survival and growth. Physiological dormancy is the most widespread form of dormancy in flowering plants, yet the seed ecology of species with this dormancy type is poorly understood in fire-prone vegetation. The role of seasonal temperatures as germination cues in these habitats is often overlooked due to a focus on direct fire cues such as heat shock and smoke, and little is known about the combined effects of multiple fire-related cues and environmental cues as these are seldom assessed in combination. We aimed to improve understanding of the germination requirements of species with physiological dormancy in fire-prone floras by investigating germination responses across members of the Rutaceae from south eastern Australia. We used a fully factorial experimental design to quantify the individual and combined effects of heat shock, smoke and seasonal ambient temperatures on germination of freshly dispersed seeds of seven species of Boronia, a large and difficult-to-germinate genus. Germination syndromes were highly variable but correlated with broad patterns in seed morphology and phylogenetic relationships between species. Seasonal temperatures influenced the rate and/or magnitude of germination responses in six species, and interacted with fire cues in complex ways. The combined effects of heat shock and smoke ranged from neutral to additive, synergistic, unitive or negative and varied with species, seasonal temperatures and duration of incubation. These responses could not be reliably predicted from the effect of the application of single cues. Based on these findings, fire season and fire intensity are predicted to affect both the magnitude and timing of seedling emergence in wild populations of species with physiological dormancy, with important implications for current fire management practices and for population

  5. ANALYSIS OF SECONDARY ORGANIC AEROSOL COMPOUNDS FROM THE PHOTOOXIDATION OF D-LIMONENE IN THE PRESENCE OF NO X AND THEIR DETECTION IN AMBIENT PM 2.5

    Science.gov (United States)

    Chemical analysis of secondary organic aerosol (SOA) from the photooxidation of a d-limonene/NOx/air mixture was carried out. SOA, generated in a smog chamber, was collected on Zefluor filters. To determine the structural characteristics of the compounds, the filter sample...

  6. Development of high temperature resistant geomembranes for oil sands secondary containments

    Energy Technology Data Exchange (ETDEWEB)

    Mills, A. [Layfield Environmental Systems Ltd., Edmonton, AB (Canada); Martin, D. [Layfield Geosynthetics and Industrial Fabrics Ltd., Edmonton, AB (Canada)

    2008-07-01

    Plastic liner materials are often adversely impacted by chemicals at elevated temperatures. Heat accelerates the oxidation of the polymeric chains, which in turn accelerates the degradation of the plastic. This paper discussed geomembrane containment systems placed under heated petroleum storage tanks at an oil sands processing plant. Various high temperature-resistant geomembrane materials were tested. Compatibility testing procedures for the various fluids contained by the systems were outlined. Installation procedures for the membranes were also discussed. The membrane systems were designed for use with heavy gas oil; light gas oil; and naphtha. Temperatures in the ground below the tanks were approximately 79 degrees C. Testing was done using sealed containers held in an oil bath at temperatures of 105 degrees C. Heat applied to the chemicals during the tests pressurized the test vessels. Liner materials used in the initial tests included an ester-based thermoplastic polyurethane liner; high density polyethylene (HDPE); linear low-density polyethylene (LLDPE), polypropylene (PP) olefins; polyvinyl chloride (PVC); and polyvinylidene (PVDF) materials. A second set of tests was then conducted using alloy materials and PVC. Heat stability tests demonstrated that the blue 0.75 mm alloy showed a tensile strength ratio within the industry's 15 per cent pass criteria. The samples were then tested with diluted bitumen and diluents at 65, 85 and 100 degrees C. The developed liners were installed underneath petroleum tanks with leak detection chambers. It was concluded that the geomembrane liners prevented the hot liquids from leaking. 4 refs., 8 tabs.

  7. Isolating lattice from electronic contributions in thermal transport measurements of metals and alloys above ambient temperature and an adiabatic model

    Science.gov (United States)

    Criss, Everett M.; Hofmeister, Anne M.

    2017-06-01

    From femtosecond spectroscopy (fs-spectroscopy) of metals, electrons and phonons reequilibrate nearly independently, which contrasts with models of heat transfer at ordinary temperatures (T > 100 K). These electronic transfer models only agree with thermal conductivity (k) data at a single temperature, but do not agree with thermal diffusivity (D) data. To address the discrepancies, which are important to problems in solid state physics, we separately measured electronic (ele) and phononic (lat) components of D in many metals and alloys over ˜290-1100 K by varying measurement duration and sample length in laser-flash experiments. These mechanisms produce distinct diffusive responses in temperature versus time acquisitions because carrier speeds (u) and heat capacities (C) differ greatly. Electronic transport of heat only operates for a brief time after heat is applied because u is high. High Dele is associated with moderate T, long lengths, low electrical resistivity, and loss of ferromagnetism. Relationships of Dele and Dlat with physical properties support our assignments. Although kele reaches ˜20 × klat near 470 K, it is transient. Combining previous data on u with each D provides mean free paths and lifetimes that are consistent with ˜298 K fs-spectroscopy, and new values at high T. Our findings are consistent with nearly-free electrons absorbing and transmitting a small fraction of the incoming heat, whereas phonons absorb and transmit the majority. We model time-dependent, parallel heat transfer under adiabatic conditions which is one-dimensional in solids, as required by thermodynamic law. For noninteracting mechanisms, k≅ΣCikiΣCi/(ΣCi2). For metals, this reduces to k = klat above ˜20 K, consistent with our measurements, and shows that Meissner’s equation (k≅klat + kele) is invalid above ˜20 K. For one mechanism with multiple, interacting carriers, k≅ΣCiki/(ΣCi). Thus, certain dynamic behaviors of electrons and phonons in metals have been

  8. The effect of ambient air temperature and precipitation on monthly counts of salmonellosis in four regions of Kazakhstan, Central Asia, in 2000-2010.

    Science.gov (United States)

    Grjibovski, A M; Kosbayeva, A; Menne, B

    2014-03-01

    We studied associations between monthly counts of laboratory-confirmed cases of salmonellosis, ambient air temperature and precipitation in four settings in Kazakhstan. We observed a linear association between the number of cases of salmonellosis and mean monthly temperature during the same months only in Astana: an increase of 1°C was associated with a 5·5% [95% confidence interval (CI) 2·2-8·8] increase in the number of cases. A similar association, although not reaching the level of significance was observed in the Southern Kazakhstan region (3·5%, 95% CI -2·1 to 9·1). Positive association with precipitation with lag 2 was found in Astana: an increase of 1 mm was associated with a 0·5% (95% CI 0·1-1·0) increase in the number of cases. A similar association, but with lag 0 was observed in Southern Kazakhstan region (0·6%, 95% CI 0·1-1·1). The results may have implications for the future patterns of salmonellosis in Kazakhstan with regard to climate change.

  9. Contraction Twinning Dominated Tensile Deformation and Subsequent Fracture in Extruded Mg-1Mn (Wt Pct) at Ambient Temperature

    Science.gov (United States)

    Chakkedath, A.; Maiti, T.; Bohlen, J.; Yi, S.; Letzig, D.; Eisenlohr, P.; Boehlert, C. J.

    2018-03-01

    Due to their excellent strength-to-weight ratio, Mg alloys are attractive for applications where weight savings are critical. However, the limited cold formability of wrought Mg alloys severely restricts their widespread usage. In order to study the role that deformation twinning might play in limiting the elongation-to-failure ({ɛ} f ), in-situ tensile tests along the extrusion axis of Mg-1Mn (wt pct) were performed at 323 K, 423 K, and 523 K. The alloy exhibited a strong basal texture such that most of the grains experienced compression along their -axis during deformation. At 323 K, fracture occurred at about 10 pct strain. Although basal, prismatic, and pyramidal slip activity was observed along with extension twinning, contraction twinning significantly influenced the deformation, and such twins evolved into {10{\\bar{1}} 1}-{10{\\bar{1}} 2} double twins. Crystal plasticity simulation showed localized shear deformation within the contraction twins and double twins due to the enhanced activity of basal slip in the reoriented twin volume. Due to this, the twin-matrix interface was identified to be a potential crack initiation site. Thus, contraction twins were considered to have led to the failure of the material at a relatively low strain, suggesting that this deformation mode is detrimental to the cold formability of Mg and its alloys. With increasing temperature, there was a significant decrease in the activity of contraction twinning as well as extension twinning, along with a decrease in the tensile strength and an increase in the {ɛ} f value. A combination of basal, prismatic, and pyramidal slips accounted for a large percentage of the observed deformation activity at 423 K and 523 K. The lack of contraction twinning was explained by the expected decrease in the critical resolved shear stress values for pyramidal slip, and the improved {ɛ} f values at elevated temperatures were attributed to the vanishing activity of contraction twinning.

  10. Predicting the behavior of a grid-connected photovoltaic system from measurements of solar radiation and ambient temperature

    International Nuclear Information System (INIS)

    Hernandez, J.; Gordillo, G.; Vallejo, W.

    2013-01-01

    Highlights: ► A model to predict in a reliable way the behavior of a GCPV system is presented. ► Radiation and temperature behavior were shaped with probability density functions. ► This probability density functions were made from real measurements. ► This model was verified for comparing their behavior with real measurements. ► It can be used in any electrical systems language which have programming routines. - Abstract: This paper presents a methodology to predict in a statistically reliable way the behavior of a grid-connected photovoltaic system. The methodology developed can be implemented either in common programming software or through an off-the-shelf simulation of electrical systems. Initially, the atmospheric parameters that influence the behavior of PV generators (radiation and temperature) are characterized in a probabilistic manner. In parallel, a model compound by various PV generator components is defined: the modules (and their electrical and physical characteristics), their connection to form the generator, and the inverter type. This model was verified for comparing their behavior with output measured on a real installed system of 3.6 kWp. The solar resource characterized and the photovoltaic system model are integrated in a non-deterministic approach using the stochastic Monte Carlo method, developed in the programming language DPL of the electrical-systems simulation software DIGSILENT®. It is done to estimate the steady-state electrical parameters describing the influence of the grid-connected photovoltaic system. Specifically, we estimated the nominal peak power of the PV generator to minimize network losses, subject to constraints on nodes voltages and conductor currents

  11. Temperature Dependency of the Correlation between Secondary Organic Aerosol and Monoterpenes Concentrations at a Boreal Forest Site in Finland

    Science.gov (United States)

    Zhou, Y.; Zhang, W.; Rinne, J.

    2016-12-01

    Climate feedbacks represent the large uncertainty in the climate projection partly due to the difficulties to quantify the feedback mechanisms in the biosphere-atmosphere interaction. Recently, a negative climate feedback mechanism whereby higher temperatures and CO2-levels boost continental biomass production, leading to increased biogenic secondary organic aerosol (SOA) and cloud condensation nuclei concentrations, tending to cause cooling, has been attached much attention. To quantify the relationship between biogenic organic compounds (BVOCs) and SOA, a five-year data set (2008, 2010-2011,2013-2014) for SOA and monoterpenes concentrations (the dominant fraction of BVOCs) measured at the SMEAR II station in Hyytiälä, Finland, is analyzed. Our results show that there is a moderate linear correlation between SOA and monoterpenes concentration with the correlation coefficient (R) as 0.66. To rule out the influence of anthropogenic aerosols, the dataset is further filtered by selecting the data at the wind direction of cleaner air mass, leading to an improved R as 0.68. As temperature is a critical factor for vegetation growth, BVOC emissions, and condensation rate, the correlation between SOA and monoterpenes concentration at different temperature windows are studied. The result shows a higher R and slope of linear regression as temperature increases. To identify the dominant oxidant responsible for the BVOC-SOA conversion, the correlations between SOA concentration and the monoterpenes oxidation rates by O3 and OH are compared, suggesting more SOA is contributed by O3 oxidation process. Finally, the possible processes and factors such as the atmospheric boundary layer depth, limiting factor in the monoterpenes oxidation process, as well as temperature sensitivity in the condensation process contributing to the temperature dependence of correlation between BVOA and SOA are investigated.

  12. Thermal conductivity of silver loaded conductive epoxy from cryogenic to ambient temperature and its application for precision cryogenic noise measurements

    Science.gov (United States)

    Amils, Ricardo I.; Gallego, Juan Daniel; Sebastián, José Luis; Muñoz, Sagrario; Martín, Agustín; Leuther, Arnulf

    2016-06-01

    The pressure to increase the sensitivity of instrumentation has pushed the use of cryogenic Low Noise Amplifier (LNA) technology into a growing number of fields. These areas range from radio astronomy and deep space communications to fundamental physics. In this context manufacturing for cryogenic environments requires a proper thermal knowledge of the materials to be able to achieve adequate design behavior. In this work, we present experimental measurements of the thermal conductivity of a silver filled conductive epoxy (EPO-TEK H20E) which is widely used in cryogenic electronics applications. The characterization has been made using a sample preparation which mimics the practical use of this adhesive in the fabrication of cryogenic devices. We apply the data obtained to a detailed analysis of the effects of the conductive epoxy in a monolithic thermal noise source used for high accuracy cryogenic microwave noise measurements. In this application the epoxy plays a fundamental role since its limited thermal conductivity allows heating the chip with relatively low power. To our knowledge, the cryogenic thermal conductivity data of this epoxy has not been reported before in the literature in the 4-300 K temperature range. A second non-conductive epoxy (Gray Scotch-Weld 2216 B/A), also widely used in cryogenic applications, has been measured in order to validate the method by comparing with previous published data.

  13. Vaulted trans-bis(salicylaldiminato)platinum(II) crystals: heat-resistant, chromatically sensitive platforms for solid-state phosphorescence at ambient temperature.

    Science.gov (United States)

    Komiya, Naruyoshi; Okada, Minoru; Fukumoto, Kanako; Kaneta, Kenji; Yoshida, Atsushi; Naota, Takeshi

    2013-04-08

    The synthesis, structure, and solid-state emission of vaulted trans-bis(salicylaldiminato)platinum(II) complexes are described. A series of polymethylene (1: n=8; 2: n=9; 3: n=10; 4: n=11; 5: n=12; 6: n=13) and polyoxyethylene (7: m=2; 8: m=3; 9: m=4) vaulted complexes (R=H (a), 3-MeO (b), 4-MeO (c), 5-MeO (d), 6-MeO (e), 4-CF3O (f), 5-CF3O (g)) was prepared by treating [PtCl2(CH3CN)2] with the corresponding N,N'-bis(salicylidene)-1,ω-alkanediamines. The trans coordination, vaulted structures, and the crystal packing of 1-9 have been unequivocally established from X-ray diffraction studies. Unpredictable, structure-dependent phosphorescent emission has been observed for crystals of the complexes under UV excitation at ambient temperature, whereas these complexes are entirely nonemissive in the solution state under the same conditions. The long-linked complex crystals 4-6, 8, and 9 exhibit intense emission (Φ77K =0.22-0.88) at 77 K, whereas short-linked complexes 1-3 and 7 are non- or slightly emissive at the same temperature (Φ77K crystals, 4a, 4b, 5c, 5e, 6c, 6e, and 9b, completely lose their high-emission properties with elevation of the temperature (Φ298K crystals, 5a, 6a, 9a, and 9d, exhibit high heat resistance towards emission decay with increasing temperature (Φ298K =0.21-0.38). Chromogenic control of solid-state emission over the range of 98 nm can be performed simply by introducing MeO groups at different positions on the aromatic rings. Orange, yellow-green, red, and yellow emissions are observed in the glass and crystalline state upon 3-, 4-, 5-, and 6-MeO substitution, respectively, whereas those with CF3 O substituents have orange emission, irrespective of the substitution position. DFT calculations (B3LYP/6-31G*, LanL2DZ) showed that such chromatic variation is ascribed to the position-specific influence of the substituents on the highest-occupied molecular orbital (HOMO) and lowest-unoccupied molecular orbital (LUMO) levels of the trans

  14. Dieta de Mazama gouazoubira (Mammalia, Cervidae en un ambiente secundario de Yungas, Argentina Diet of Mazama gouazoubira (Mammalia, Cervidae in a secondary environment of Yungas, Argentina

    Directory of Open Access Journals (Sweden)

    Enrique Richard

    Full Text Available The trophic spectrum of the Brown brocket deer, Mazama gouazoubira Fischer, 1814, was analyzed between September 1993 to February 1994, in a secondary environment of Yungas, Argentina and in semicaptivity conditions. Seventy three vegetable species and two fungi species were recorded. It was registered also the consumption of ticks, salt, land, bricks and scats of another animals. The main vegetable parts consumed in order of importance were young leaves and outbreaks (green parts, fruit and flowers.

  15. Impact of lyophilized Lactobacillus salivarius DSPV 001P administration on growth performance, microbial translocation, and gastrointestinal microbiota of broilers reared under low ambient temperature.

    Science.gov (United States)

    Blajman, J E; Olivero, C A; Fusari, M L; Zimmermann, J A; Rossler, E; Berisvil, A P; Romero Scharpen, A; Astesana, D M; Soto, L P; Signorini, M L; Zbrun, M V; Frizzo, L S

    2017-10-01

    This study was undertaken with the aim of investigating the effects of dietary supplementation of probiotic strain Lactobacillus salivarius DSPV 001P on growth performance, microbial translocation, and gastrointestinal microbiota of broilers reared under low ambient temperature. Two hundred and forty, one-day-old male Cobb broilers were randomly distributed into two treatment groups, a probiotic group and a control group, with four replicates per treatment and 30 broilers per replicate. The temperature of the broiler house was maintained at 18-22°C during the first three weeks, after which the temperature was at range of 8°C to 12°C. The results showed that probiotic treatment significantly improved body weight of broilers when compared with the control group. After 42days, the weight means were 2905±365.4g and 2724±427.0g, respectively. Although there were no significant differences, dietary inclusion of L. salivarius tended to increase feed intake and to reduce feed conversion ratio during the six-week experimental period. Similarly, supplementation tended to reduce the rate of mortality, with 12 deaths occurring in the probiotic group, and 20 in the control group. However, no differences were observed in intestinal bacterial concentrations of Enterobacteriaceae, E.coli, and lactic acid bacteria in both crop and caecum among treatments. Through our study, it appears that L. salivarius DSPV 001P was non-pathogenic, safe and beneficial to broilers, which implies that it could be a promising feed additive, thus enhancing the growth performance of broilers and improving their health. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Ambient temperature does not affect fuelling rate in absence of digestive constraints in long-distance migrant shorebird fuelling up in captivity.

    Science.gov (United States)

    Petit, Magali; Vézina, François; Piersma, Theunis

    2010-08-01

    Pre-flight fuelling rates in free-living red knots Calidris canutus, a specialized long-distance migrating shorebird species, are positively correlated with latitude and negatively with temperature. The single published hypothesis to explain these relationships is the heat load hypothesis that states that in warm climates red knots may overheat during fuelling. To limit endogenous heat production (measurable as basal metabolic rate BMR), birds would minimize the growth of digestive organs at a time they need. This hypothesis makes the implicit assumption that BMR is mainly driven by digestive organ size variation during pre-flight fuelling. To test the validity of this assumption, we fed captive knots with trout pellet food, a diet previously shown to quickly lead to atrophied digestive organs, during a fuelling episode. Birds were exposed to two thermal treatments (6 and 24 degrees C) previously shown to generate different fuelling rates in knots. We made two predictions. First, easily digested trout pellet food rather than hard-shelled prey removes the heat contribution of the gut and would therefore eliminate an ambient temperature effect on fuelling rate. Second, if digestive organs were the main contributors to variations in BMR but did not change in size during fuelling, we would expect no or little change in BMR in birds fed ad libitum with trout pellets. We show that cold-acclimated birds maintained higher body mass and food intake (8 and 51%) than warm-acclimated birds. Air temperature had no effect on fuelling rate, timing of fuelling, timing of peak body mass or BMR. During fuelling, average body mass increased by 32% while average BMR increased by 15% at peak of mass and 26% by the end of the experiment. Our results show that the small digestive organs characteristic of a trout pellet diet did not prevent BMR from increasing during premigratory fuelling. Our results are not consistent with the heat load hypothesis as currently formulated.

  17. Effects of ambient temperature and dietary glycerol addition on growth performance, blood parameters and immune cell populations of Korean cattle steers

    Directory of Open Access Journals (Sweden)

    Hyeok Joong Kang

    2017-04-01

    Full Text Available Objective This study was performed to evaluate whether ambient temperature and dietary glycerol addition affect growth performance, and blood metabolic and immunological parameters, in beef cattle. Methods Twenty Korean cattle steers (405.1±7.11 kg of body weight [BW], 14.2±0.15 months of age were divided into a conventional control diet group (n = 10 and a 2% glycerol- added group (n = 10. Steers were fed 1.6% BW of a concentrate diet and 0.75% BW of a timothy hay diet for 8 weeks (4 weeks from July 28th to August 26th and 4 weeks from August 27th to September 26th. Blood was collected four times on July 28th, August 11th, August 27th, and September 26th. Results The maximum indoor ambient temperature-humidity index in August (75.8 was higher (p<0.001 than that in September (70.0, and in August was within the mild heat stress (HS category range previously reported for dairy cattle. The average daily gain (ADG; p = 0.03 and feed efficiency (p<0.001 were higher in hotter August than in September. Glycerol addition did not affect ADG and feed efficiency. Neither month nor glycerol addition affected blood concentrations of cortisol, triglyceride, or non-esterified fatty acid. Blood concentrations of cholesterol, low-density lipoprotein, high-density lipoprotein, glucose, and albumin were lower (p<0.05 on August 27th than on September 26 th, and blood phosphorus, calcium and magnesium concentrations were also lower on August 27th than on September 27th. Glycerol addition did not affect these blood parameters. Percentages of CD4+ T cells and CD8+ T cells were higher (p<0.05 on July 28th than on August 27th and September 26th. The blood CD8+ T cell population was lower in the glycerol supplemented-group compared to the control group on July 28th and August 27th. Conclusion Korean cattle may not be significantly affected by mild HS, considering that growth performance of cattle was better in hotter conditions, although some changes in blood metabolic

  18. Solids filtration of high-temperature feedwater in a PWR secondary circuit: Final report

    International Nuclear Information System (INIS)

    Siegwarth, D.P.; Friedman, K.A.; Chakravorti, R.K.; Alibutod, L.J.

    1988-11-01

    Pressurized water reactor steam generators and turbines have experienced a variety of corrosion problems as a result of ionic, corrosion product and oxidizing species transport to the steam generators. Installation of high temperature filters on final feedwater, high pressure drains and moisture separator drains to reduce corrosion product ingress to the steam generators of a 1160 MWe design basis plant are specified and evaluated. Cost estimates for installing electromagnetic filters, and added operating and maintenance costs are given. 18 refs., 12 figs., 9 tabs

  19. Periodismo ambiental

    Directory of Open Access Journals (Sweden)

    Lucía Lemos

    2015-01-01

    Full Text Available Los periodistas toman el tema del medio ambiente cada vez más en serio. El uso de temas relacionados con el medio ambiente, debe estar ligado al análisis socio-económico y a las posibilidades de comunicación y educación de diferentes regiones del mundo. A continuación se presenta un resumen de la situación ambiental, las acciones de prensa y comunicación que se llevan a cabo en América Central (Panamá, El Salvador, Costa Rica y en Sudamérica Brasil,Colombia, Chile, México, y Perú. Se concluye en la necesidad de formar hábitos ecológicos. Los comunicadores deben presentar soluciones a los problemas, fomentar campañas comunes, compartir información y velar por el ambiente ambiente para que las generaciones futuras no tengan que perecer.

  20. Dependence of the coefficient of environmental thermal losses of radiation-absorbing thermal exchange panels of flat solar collectors for heating heat-transfer fluid from their average operating and ambient temperatures

    International Nuclear Information System (INIS)

    Avezova, N.R.; Avezov, R.R.

    2015-01-01

    The approximation formula is derived for calculating the normalized coefficient of thermal losses of flat solar collectors (FSCs) for heating heat-transfer fluid (HTF). These are used in hot water supply systems in the warmer part of the year, depending on the average working surface temperature of their radiation-absorbing thermal exchange panels (RATEPs) (t - wsr ) and the ambient temperature (t amb ) in their realistic variation range. (author)

  1. Effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid supplementation on growth performance, indices of ascites syndrome, and antioxidant capacity of broilers reared at low ambient temperature

    Science.gov (United States)

    Yang, G. L.; Zhang, K. Y.; Ding, X. M.; Zheng, P.; Luo, Y. H.; Bai, S. P.; Wang, J. P.; Xuan, Y.; Su, Z. W.; Zeng, Q. F.

    2016-08-01

    This study examined the effects of dietary DL-2-hydroxy-4(methylthio)butanoic acid (DL-HMTBA) supplementation on growth performance, antioxidant capacity, and ascites syndrome (AS) in broilers reared at low ambient temperature (LAT) from 7 to 28 days of age. Eight hundred 7-day-old broilers were randomly assigned to two ambient temperatures (LAT and normal ambient temperature [NAT]), four supplemental DL-HMTBA levels (0.17, 0.34, 0.51, and 0.68 %) of the basal diet in a 2 × 4 factorial arrangement (ten replicate pens; ten birds/pen). LAT and NAT indicate temperatures of 12-14 and 24-26 °C in two chambers, respectively, and broilers were reared at these temperatures from 7 to 28 days of age. LAT significantly decreased body weight gain ( P weight ratio (RV/TV) at 21 days ( P = 0.012) and 28 days ( P = 0.046). Supplementation of DL-HMTBA markedly decreased RV/TV at day 28 ( P = 0.021), RBC (day 21, P = 0.008), HCT (day 21, P supplemental DL-HMTBA levels in basal diet of broilers aged from 7 to 28 days under low or normal temperatures were similar, so the authors recommended supplemental of DL-HMTBA level was 0.46 %.

  2. Application of Simplified Anaerobic Digestion Models (SADM’s for Studying the Biodegradability and Kinetics of Cow Manure at Ambient Temperature

    Directory of Open Access Journals (Sweden)

    Yusuf O.L. MOMOH

    2014-02-01

    Full Text Available The application of a set of simplified anaerobic digestion models (SADM’s to describe the anaerobic biodegradability and kinetics of cow manure at ambient temperature was conducted in this study. It was observed that the Hill’s based biogas yield rate model was the most appropriate in describing biogas yield rate from cow manure. Parameter estimation revealed that the half saturation constant expressed as acidified substrate and volatile solids (VS equivalent were 0.163g/l and 21.9g VS/l respectively while the maximum biogas yield rate was estimated to be 1.957ml/g VS/day. The coefficient of acidogenic bacteria adaptation (n and coefficient of acetogenic/methanogenic bacterial cooperativity (m were estimated to be 1.28 and 0.65 respectively. The poor cooperativity amongst the acetogenic/methanogenic bacterial species can be attributed to poor adaptation, possibly due to interaction between ammonia and volatile fatty acids. In addition, the biodegradability and recalcitrance was estimated to be 0.42 and 0.433 respectively, while hydrolysis/acidogenesis was identified as the rate limiting step.

  3. The influence of boron on the crystal structure and properties of mullite. Investigations at ambient, high-pressure, and high-temperature conditions

    Energy Technology Data Exchange (ETDEWEB)

    Luehrs, Hanna

    2013-11-21

    Mullite is one of the most important synthetic compounds for advanced structural and functional ceramic materials. The crystal structure of mullite with the composition Al{sub 2}[Al{sub 2+2x}Si{sub 2-2x}]O{sub 10-x} can incorporate a large variety of foreign cations, including (amongst others) significant amounts of boron. However, no chemical or crystal structure analyses of boron-mullites (B-mullites) were available prior to this work, thus representing the key aspects of this thesis. Furthermore, the influence of boron on selected properties of mullite under ambient, high-temperature, and high-pressure conditions are addressed. Starting from a 3:2 mullite composition (Al{sub 4.5}Si{sub 1.5}O{sub 9.75}), the initial hypothesis for this study was a 1:1 isomorphous replacement of silicon by boron according to the coupled substitution mechanism: 2 Si{sup 4+} + O{sup 2-} → 2 B{sup 3+} + □. Based on a series of compounds synthesized from sol-gel derived precursors at ambient pressure and 1200 C, the formation conditions and physical properties of B-mullites were investigated. The formation temperature for B-mullites decreases with increasing boron-content, as revealed by thermal analyses. An anisotropic development of lattice parameters is observed: Whereas lattice parameters a and b only exhibit minor changes, a linear relationship between lattice parameter c and the amount of boron in the crystal structure was established, on the basis of prompt gamma activation analyses (PGAA) and Rietveld refinements. According to this relationship about 15% of the silicon in mullite can be replaced by boron yielding single-phase B-mullite. B-mullites with significantly higher (∝ factor 3) boron-contents in the mullite structure were also observed but the respective samples contain alumina impurities. Fundamental new details regarding the response of B-mullite to high-temperature and highpressure are presented in this thesis. On the one hand, long-term thermal stability at

  4. Effect of Dietary L-ascorbic Acid (L-AA on Production Performance, Egg Quality Traits and Fertility in Japanese Quail ( at Low Ambient Temperature

    Directory of Open Access Journals (Sweden)

    N. Shit

    2012-07-01

    Full Text Available Environmental stress boosts the levels of stress hormones and accelerates energy expenditure which subsequently imbalance the body’s homeostasis. L-ascorbic acid (L-AA has been recognized to mitigate the negative impact of environmental stress on production performances in birds. The present investigation was carried out to elucidate the effect of different dietary levels of L-AA on production performance, egg quality traits and fertility in Japanese quail at low ambient temperature. Sixty matured females (15 wks were equally divided into three groups (20/group based on the different dietary levels of L-AA (0, 250 and 500 ppm and coupled with an equal number of males (1:1 obtained from the same hatch. They were managed in uniform husbandry conditions without restriction of feed and water at 14 h photo-schedule. Except for feed efficiency, body weight change, feed consumption and hen-day egg production were recorded highest in 500 ppm L-AA supplemented groups. Among the all egg quality traits studied, only specific gravity, shell weight and thickness differed significantly (p<0.05 in the present study. Fertility was improved significantly (p<0.01 to a dose dependent manner of L-AA. The findings of the present study concluded that dietary L-AA can be a caring management practice at least in part to alleviate the adverse effect of cold induced stress on production performance in Japanese quail.

  5. Influence of applied voltage on the performance of bioelectrochemical anaerobic digestion of sewage sludge and planktonic microbial communities at ambient temperature.

    Science.gov (United States)

    Feng, Qing; Song, Young-Chae; Bae, Byung-Uk

    2016-11-01

    The influence of applied voltage on the bioelectrochemical anaerobic digestion of sewage sludge was studied at ambient temperature (25±2°C). The stability of the bioelectrochemical anaerobic digestion was considerably good in terms of pH, alkalinity and VFAs at 0.3V and 0.5V, but VFA accumulation occurred at 0.7V. The specific methane production rate (370mLCH4/L.d) was the highest at 0.3V, but the methane content (80.6%) in biogas and the methane yield (350mLCH4/gCODr) were higher at 0.5V, significantly better than those of 0.7V. The VS removal efficiency was 64-66% at 0.3V and 0.5V, but only 31% at 0.7V. The dominant species of planktonic microbial communities was Cloacamonas at 0.3V and 0.5V, but the percentage of hydrolytic bacteria species such as Saprospiraceae, Fimbriimonas, and Ottowia pentelensis was much higher at 0.7V. The optimal applied voltage for bioelectrochemical anaerobic digestion was 0.3-0.5V according to digestion performance and planktonic microbial communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. A novel gel-based method for self-collection and ambient temperature postal transport of urine for PCR detection of Chlamydia trachomatis.

    Science.gov (United States)

    Bialasiewicz, S; Whiley, D M; Buhrer-Skinner, M; Bautista, C; Barker, K; Aitken, S; Gordon, R; Muller, R; Lambert, S B; Debattista, J; Nissen, M D; Sloots, T P

    2009-04-01

    The aim of this study was to develop a novel urine transport method to be used in self-collection-based screening for Chlamydia trachomatis. The method needed to be suitable for C trachomatis PCR detection, be economical and suitable for transport by standard envelope mailing. An anhydrous gel composed of super-absorbent polymer and buffering agent was used to desiccate urine into a dry granulous state, which could subsequently be reconstituted upon arrival at a laboratory. DNA was then extracted from the reconstituted solution using the Roche MagNA Pure protocol for the detection of C trachomatis by PCR. Collections of urine specimens from three populations with widely differing chlamydia prevalence (100%,n = 56; 47%, n = 70; 3%, n = 97) were used. We determined the gel method's impact on C trachomatis PCR sensitivity and specificity using neat and gel-processed urine specimens. An equine herpes virus PCR was used to test for assay inhibition. Overall, the sensitivity of the gel-based method ranged from 94.6-100% compared with neat urine, with a specificity of 100%. No PCR inhibition or decrease in analytical sensitivity was observed using the gel-processed extracts. The gel-based method was found to be suitable for the detection of C trachomatis by PCR. In addition, its ease of use, effectiveness at ambient temperature and low cost makes it well-suited for self-collection kits used in population-based C trachomatis screening, particularly for geographically and socially isolated individuals.

  7. Dynamic Polymorph Formation during Evaporative Crystallization from Solution: The Key Role of Liquid-Like Clusters as "Crucible" at Ambient Temperature.

    Science.gov (United States)

    Oka, Narumi; Ito, Fuyuki; Haketa, Yohei; Maeda, Hiromitsu; Miyano, Tetsuya; Tohnai, Norimitsu; Ito, Syoji; Miyasaka, Hiroshi; Ozeki, Sumio

    2018-03-20

    Understanding the polymorph phenomenon for organic crystals is essential for the development of organic solid materials. Here, the fluorescence study of the evaporative crystallization of 1,3-dipyrrol-2-yl-1,3-propanedione boron difluoride complex (1), which has three polymorphs showing different emission profiles, is reported. The droplet of 1 in 1,2-dichloroethane showed blue emission just after dropping. Solids with bluish-green emission were observed. As time elapsed, a solid with red or orange emission was observed around the droplet. Time evolution of the fluorescence spectra, observed for the first time, implied that the molten state of 1 was observed by emission of an intermediate, even at ambient temperature. These findings suggested that the liquid-like cluster incidentally forms an ordered array as the crystallites nucleate. The liquid-like cluster can be considered as the "crucible" in the nucleation of polymorphs. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Grafting of Poly(methyl methacrylate Brushes from Magnetite Nanoparticles Using a Phosphonic Acid Based Initiator by Ambient Temperature Atom Transfer Radical Polymerization (ATATRP

    Directory of Open Access Journals (Sweden)

    Babu Kothandapani

    2008-01-01

    Full Text Available AbstractPoly(methyl methacrylate in the brush form is grown from the surface of magnetite nanoparticles by ambient temperature atom transfer radical polymerization (ATATRP using a phosphonic acid based initiator. The surface initiator was prepared by the reaction of ethylene glycol with 2-bromoisobutyrl bromide, followed by the reaction with phosphorus oxychloride and hydrolysis. This initiator is anchored to magnetite nanoparticles via physisorption. The ATATRP of methyl methacrylate was carried out in the presence of CuBr/PMDETA complex, without a sacrificial initiator, and the grafting density is found to be as high as 0.90 molecules/nm2. The organic–inorganic hybrid material thus prepared shows exceptional stability in organic solvents unlike unfunctionalized magnetite nanoparticles which tend to flocculate. The polymer brushes of various number average molecular weights were prepared and the molecular weight was determined using size exclusion chromatography, after degrafting the polymer from the magnetite core. Thermogravimetric analysis, X-ray photoelectron spectra and diffused reflection FT-IR were used to confirm the grafting reaction.

  9. Chemical composition and source of fine and nanoparticles from recent direct injection gasoline passenger cars: Effects of fuel and ambient temperature

    Science.gov (United States)

    Fushimi, Akihiro; Kondo, Yoshinori; Kobayashi, Shinji; Fujitani, Yuji; Saitoh, Katsumi; Takami, Akinori; Tanabe, Kiyoshi

    2016-01-01

    Particle number, mass, and chemical compositions (i.e., elemental carbon (EC), organic carbon (OC), elements, ions, and organic species) of fine particles emitted from four of the recent direct injection spark ignition (DISI) gasoline passenger cars and a port fuel injection (PFI) gasoline passenger car were measured under Japanese official transient mode (JC08 mode). Total carbon (TC = EC + OC) dominated the particulate mass (90% on average). EC dominated the TC for both hot and cold start conditions. The EC/TC ratios were 0.72 for PFI and 0.88-1.0 (average = 0.92) for DISI vehicles. A size-resolved chemical analysis of a DISI car revealed that the major organic components were the C20-C28 hydrocarbons for both the accumulation-mode particles and nanoparticles. Contribution of engine oil was estimated to be 10-30% for organics and the sum of the measured elements. The remaining major fraction likely originated from gasoline fuel. Therefore, it is suggested that soot (EC) also mainly originated from the gasoline. In experiments using four fuels at three ambient temperatures, the emission factors of particulate mass were consistently higher with regular gasoline than with premium gasoline. This result suggest that the high content of less-volatile compounds in fuel increase particulate emissions. These results suggest that focusing on reducing fuel-derived EC in the production process of new cars would effectively reduce particulate emission from DISI cars.

  10. Mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. Effect of pre-treatment at elevated temperature

    DEFF Research Database (Denmark)

    Gavala, Hariklia N.; Yenal, U.; Skiadas, Ioannis V.

    2003-01-01

    Anaerobic digestion is an appropriate technique for the treatment of sludge before final disposal and it is employed worldwide as the oldest and most important process for sludge stabilization. In general, mesophilic anaerobic digestion of sewage sludge is more widely used compared to thermophilic...... digestion. Furthermore, thermal pre-treatment is suitable for the improvement of stabilization, enhancement of dewatering of the sludge, reduction of the numbers of pathogens and could be realized at relatively low cost especially at low temperatures. The present study investigates (a) the differences...... between mesophilic and thermophilic anaerobic digestion of sludge and (b) the effect of the pretreatment at 70 degreesC on mesophilic and thermophilic anaerobic digestion of primary and secondary sludge. The pretreatment step showed very positive effect on the methane potential and production rate upon...

  11. Room Temperature Reactivity Of Silicon Nanocrystals With Solvents: The Case Of Ketone And Hydrogen Production From Secondary Alcohols: Catalysis?

    KAUST Repository

    El Demellawi, Jehad K.

    2015-05-29

    Although silicon nanoparticles dispersed in liquids are used in various applications ranging from bio-labeling to hydrogen production, their reactivities with their solvents and their catalytic properties re-main still unexplored. Here, we discovered that, because of their surface structures and mechanical strain, silicon nanoparticles react strongly with their solvents and may act as catalysts for the dehydrogenation, at room temperature, of secondary alcohols (e.g. isopropanol) to ketones and hydrogen. This catalytic reaction was followed by gas chromatography, pH measurements, mass spectroscopy and solidstate NMR. This discovery provides new understanding of the role played by silicon nanoparticles, and nanosilicon in general, in their stability in solvents in general as well as being candidates in catalysis.

  12. A stochastic model for transmission, extinction and outbreak of Escherichia coli O157:H7 in cattle as affected by ambient temperature and cleaning practices

    KAUST Repository

    Wang, Xueying

    2013-07-18

    Many infectious agents transmitting through a contaminated environment are able to persist in the environment depending on the temperature and sanitation determined rates of their replication and clearance, respectively. There is a need to elucidate the effect of these factors on the infection transmission dynamics in terms of infection outbreaks and extinction while accounting for the random nature of the process. Also, it is important to distinguish between the true and apparent extinction, where the former means pathogen extinction in both the host and the environment while the latter means extinction only in the host population. This study proposes a stochastic-differential equation model as an approximation to a Markov jump process model, using Escherichia coli O157:H7 in cattle as a model system. In the model, the host population infection dynamics are described using the standard susceptible-infected-susceptible framework, and the E. coli O157:H7 population in the environment is represented by an additional variable. The backward Kolmogorov equations that determine the probability distribution and the expectation of the first passage time are provided in a general setting. The outbreak and apparent extinction of infection are investigated by numerically solving the Kolmogorov equations for the probability density function of the associated process and the expectation of the associated stopping time. The results provide insight into E. coli O157:H7 transmission and apparent extinction, and suggest ways for controlling the spread of infection in a cattle herd. Specifically, this study highlights the importance of ambient temperature and sanitation, especially during summer. © 2013 Springer-Verlag Berlin Heidelberg.

  13. Effect of ambient temperature on the thermoregulatory and locomotor stimulant effects of 4-methylmethcathinone in Wistar and Sprague-Dawley rats.

    Directory of Open Access Journals (Sweden)

    M Jerry Wright

    Full Text Available The drug 4-methylmethcathinone (4-MMC; aka, mephedrone, MMCAT, "plant food", "bath salts" is a recent addition to the list of popular recreational psychomotor-stimulant compounds. Relatively little information about this drug is available in the scientific literature, but popular media reports have driven recent drug control actions in the UK and several US States. Online user reports of subjective similarity to 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy" prompted the current investigation of the thermoregulatory and locomotor effects of 4-MMC. Male Wistar and Sprague-Dawley rats were monitored after subcutaneous administration of 4-MMC (1-10 mg/kg using an implantable radiotelemetry system under conditions of low (23°C and high (27°C ambient temperature. A reliable reduction of body temperature was produced by 4-MMC in Wistar rats at 23°C or 27°C with only minimal effect in Sprague-Dawley rats. Increased locomotor activity was observed after 4-MMC administration in both strains with significantly more activity produced in the Sprague-Dawley strain. The 10 mg/kg s.c. dose evoked greater increase in extracellular serotonin, compared with dopamine, in the nucleus accumbens. Follow-up studies confirmed that the degree of locomotor stimulation produced by 10 mg/kg 4-MMC was nearly identical to that produced by 1 mg/kg d-methamphetamine in each strain. Furthermore, hypothermia produced by the serotonin 1(A/7 receptor agonist 8-hydroxy-N,N-dipropyl-2-aminotetralin (8-OH-DPAT was similar in each strain. These results show that the cathinone analog 4-MMC exhibits thermoregulatory and locomotor properties that are distinct from those established for methamphetamine or MDMA in prior work, despite recent evidence of neuropharmacological similarity with MDMA.

  14. Aging of secondary organic aerosol generated from the ozonolysis of α-pinene: effects of ozone, light and temperature

    Science.gov (United States)

    Denjean, C.; Formenti, P.; Picquet-Varrault, B.; Camredon, M.; Pangui, E.; Zapf, P.; Katrib, Y.; Giorio, C.; Tapparo, A.; Temime-Roussel, B.; Monod, A.; Aumont, B.; Doussin, J. F.

    2015-01-01

    A series of experiments was conducted in the CESAM (French acronym for Experimental Multiphasic Atmospheric Simulation Chamber) simulation chamber to investigate the evolution of the physical and chemical properties of secondary organic aerosols (SOAs) during different forcings. The present experiments represent a first attempt to comprehensively investigate the influence of oxidative processing, photochemistry, and diurnal temperature cycling upon SOA properties. SOAs generated from the ozonolysis of α-pinene were exposed under dry conditions (ozone concentrations, (2) light (under controlled temperature conditions) or (3) light and heat (6 °C light-induced temperature increase), and the resultant changes in SOA optical properties (i.e. absorption and scattering), hygroscopicity and chemical composition were measured using a suite of instrumentation interfaced to the CESAM chamber. The complex refractive index (CRI) was derived from integrated nephelometer measurements of 525 nm wavelength, using Mie scattering calculations and measured number size distributions. The particle size growth factor (GF) was measured with a hygroscopic tandem differential mobility analyzer (H-TDMA). An aerosol mass spectrometer (AMS) was used for the determination of the f44 / f43 and O : C ratio of the particles bulk. No change in SOA size or chemical composition was observed during O3 and light exposure at constant temperature; in addition, GF and CRI of the SOA remained constant with forcing. On the contrary, illumination of SOAs in the absence of temperature control led to an increase in the real part of the CRI from 1.35 (±0.03) to 1.49 (±0.03), an increase of the GF from 1.04 (±0.02) to 1.14 (±0.02) and an increase of the f44 / f43 ratio from 1.73 (±0.03) to 2.23 (±0.03). The simulation of the experiments using the master chemical mechanism (MCM) and the Generator for Explicit Chemistry and Kinetics of Organics in the Atmosphere (GECKO-A) shows that these changes resulted

  15. Um banho termostático de baixo custo (temperatura ambiente até 0ºC A low cost thermal bath (room temperature to 0 ºC

    Directory of Open Access Journals (Sweden)

    Cristina M. Quintella

    2003-01-01

    Full Text Available Thermal baths to decrease ambient temperature are an indispensable tool for most research and teaching laboratories, especially those in tropical or equatorial regions. A simple and inexpensive thermal bath has been developed based on a scratched compressor. It has three possible setups for cooling: sample immersed into the bath, sample flowing through the bath, and cooling liquid flowing in a jacket around the sample. It has been tested for 40 months. The temperature ranges from room temperature to 0 °C, when using water. The repeatability is better than 3% and the precision varies from 0.5% to 2%.

  16. Role of ammonium ion and transition metals in the formation of secondary organic aerosol and metallo-organic complex within fog processed ambient deliquescent submicron particles collected in central part of Indo-Gangetic Plain.

    Science.gov (United States)

    Singh, Dharmendra Kumar; Gupta, Tarun

    2017-08-01

    In this study we observed the role of ammonium ion (NH 4 + ) and transition metals (Fe, Mn, Cr, and Cu) present in ambient submicron particles in stabilizing and enhancing the yield of water soluble organic carbon (WSOC). A good correlation of WSOC with transition metals and NH 4 + was found (R 2  = 0.87 and 0.71), respectively within foggy episode collected ambient PM 1 (particles having aerodynamic diameter ≤1.0 μm) suggesting plausibleness of alternate oxidation (primarily various carbonyls into their respective organic acids, esters and other derivatives.) and aging mechanisms. Molar concentration of ammonium ion was observed to be exceeded over and above to require in neutralizing the sulphate and nitrate which further hints its role in the neutralization, stabilization and enhancement of subset of WSOC such as water soluble organic acids. Transition metals were further apportioned using enrichment factor analysis. The source of Fe, Mn, and Cr was found to be crustal and Cu was tagged to anthropogenic origin. This study also described the plausible role of significant predictors (Fe and Cu) in the secondary organic aerosol (SOA) formation through effect of Fenton chemistry. Mass-to-charge ratio of identified oxalic acid from our published recent field study (carried out from same sampling location) was used for understanding the possible metallo-organic complex with Fe supports the substantial role of Fe in SOA formation in the deliquescent submicron particles facilitated by aqueous-phase chemistry. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Structure and properties of Fe-modified Na[subscript 0.5]Bi[subscript 0.5]TiO[subscript 3] at ambient and elevated temperature

    Energy Technology Data Exchange (ETDEWEB)

    Aksel, Elena; Forrester, Jennifer S.; Kowalski, Benjamin; Deluca, Marco; Damjanovic, Dragan; Jones, Jacob L. (SFIT); (Montanuniversität); (Florida)

    2012-03-15

    Sodium bismuth titanate (NBT) ceramics are among the most promising lead-free materials for piezoelectric applications. This work reports the crystal structure and phase evolution of NBT and Fe-modified NBT (from 0-2 at.% Fe) using synchrotron x-ray diffraction and Raman spectroscopy, at both ambient and elevated temperatures. The crystallographic results are discussed with reference to permittivity and piezoelectric thermal depolarization measurements of the same compositions. Changes in the depolarization temperature due to Fe substitution were detected by Raman spectroscopy and were found to correlate closely with depolarization temperatures obtained from converse piezoelectric coefficient and permittivity measured in situ. The depolarization temperatures obtained from direct piezoelectric coefficient measured ex situ as well as the phase transition temperatures obtained from synchrotron x-ray diffraction were found to be at higher temperatures. The mechanisms underlying the relationship between permittivity and piezoelectric depolarization to structural transitions observed in Raman spectroscopy and x-ray diffraction are discussed.

  18. Heat Transfer and Observation of Droplet-Surface Interactions During Air-Mist Cooling at CSP Secondary System Temperatures

    Science.gov (United States)

    Huerta L., Mario E.; Mejía G., M. Esther; Castillejos E., A. Humberto

    2016-04-01

    Air-mists are key elements in the secondary cooling of modern thin steel slab continuous casters. The selection of water, W, and air, A, flow rates, and pressures in pneumatic nozzles open up a wide spectrum of cooling possibilities by their influence on droplet diameter, d, droplet velocity, v, and water impact flux, w. Nonetheless, due to the harsh environment resulting from the high temperatures and dense mists involved, there is very little information about the correlation between heat flux extracted, - q, and mist characteristics, and none about the dynamics of drop-wall interactions. For obtaining both kinds of information, this work combines a steady-state heat flux measuring method with a visualization technique based on a high-speed camera and a laser illumination system. For wall temperatures, T w, between ~723 K and ~1453 K (~450 °C and ~1180 °C), which correspond to film boiling regime, it was confirmed that - q increases with increase in v, w, and T w and with decrease in d. It should be noticed, however, that the increase in w generally decreases the spray cooling effectiveness because striking drops do not evaporate efficiently due to the interference by liquid remains from previous drops. Visualization of the events happening close to the surface also reveals that the contact time of the liquid with the surface is very brief and that rebounding, splashing, sliding, and levitation of drops lead to ineffective contact with the surface. At the center of the mist footprint, where drops impinge nearly normal to the surface those with enough momentum establish intimate contact with it before forming a vapor layer that pushes away the remaining liquid. Also, some drops are observed sliding upon the surface or levitating close to it; these are drops with low momentum which are influenced by the deflecting air stream. At footprint positions where oblique impingement occurs, frequently drops are spotted sliding or levitating and liquid films flowing in

  19. 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

    regionalization method algorithmically forms eight climatically homogeneous regions for Conterminous US from satellite Remote Sensing inputs. The relative risk of hospitalizations due to extreme ambient temperature varied across climatic regions. Difference in regional hospitalization rates suggests presence of an adaptation effect to a prevailing climate. In various climatic regions the hospitalizations peaked earlier than the peak of exposure. This suggests disproportionally high impact of extreme weather events, such as cold spells or heat waves when they occur early in the season. These findings provide an insight into the use of high frequency disjoint data sets for the assessment of the magnitude, timing, synchronization and non-linear properties of adverse health consequences due to exposure to extreme weather events to the elderly in defined climatic regions. These findings assist in the creation of decision support frameworks targeting preventions and adaptation strategies such as improving infrastructure, providing energy assistance, education and early warning notifications for the vulnerable population. This dissertation offers a number of methodological innovations for the assessment of the high frequency spatio-temporal and non-linear impacts of extreme weather events on human health. These innovations help to ensure an improved protection of the elderly population, aid policy makers in the development of efficient disaster prevention strategies, and facilitate more efficient allocation of scarce resources.

  20. Blood and Milk Contents of Triiodothyronine (T3) and Cortisol in Lactating Buffaloes and Changes in Milk Yield and Composition as a Function of Lactation Number and Ambient Temperature

    International Nuclear Information System (INIS)

    Habeeb, A.M. Al-Saied.; Ibrahim, M.Kh.

    2000-01-01

    The effect of lactation number and ambient temperature on T 3 and cortisol levels in milk and blood and milk composition of lactating Water buffaloes was the objective of this study. Two experiment were carried out on 72 animals in two periods through 1994. The first one was carried out on 36 animals during February, where the average of ambient temperature was 17.5 degree while the second was conducted on another 36 animals during July where the average of ambient temperature was 37.1 degree. In both two periods, the animals were classified according to lactation number into 6 equal groups from the 1 st to the 6 Th lactation number. The data showed that milk yield and T-3 either in milk or in blood besides milk fat, protein and lactose were significantly lower in july than in february. Whereas the opposite trend was noted for cortisol levels either in milk or in blood. Concerning the effect of lactation lactation number, it was observed that milk and blood T 3 , mil and blood cortisol, milk fat, protein and lactose were affected significantly by lactation number

  1. Fast and Living Ring-Opening Polymerization of α-Amino Acid N-Carboxyanhydrides Triggered by an "Alliance" of Primary and Secondary Amines at Room Temperature

    KAUST Repository

    Zhao, Wei

    2015-04-13

    A novel highly efficient strategy, based on an "alliance" of primary and secondary amine initiators, was successfully developed allowing the fast and living ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCAs) at room temperature. (Chemical Equation Presented). © 2015 American Chemical Society.

  2. Ambient diagnostics

    CERN Document Server

    Cai, Yang

    2014-01-01

    Part I. FundamentalsIntroductionWhat is Ambient Diagnostics?Diagnostic ModelsMultimedia IntelligenceCrowd SourcingSoft SensorsScience of SimplicityPersonal DiagnosesBasic AlgorithmsBasic ToolsSummaryProblemsTransformationEarly Discoveries of Heartbeat PatternsTransforms, Features, and AttributesSequential FeaturesSpatiotemporal FeaturesShape FeaturesImagery FeaturesFrequency Domain FeaturesMulti-Resolution FeaturesSummaryProblemsPattern RecognitionSimilarities and DistancesClustering MethodsClassification MethodsClassifier Accuracy MeasuresSummaryProblemsPart II. Multimedia IntelligenceSound RecognitionMicrophone AppsModern Acoustic Transducers (Microphones)Frequency Response CharacteristicsDigital Audio File FormatsHeart Sound SensingLung Sound SensingSnore MeterSpectrogram (STFT)Ambient Sound AnalysisSound RecognitionRecognizing Asthma SoundPeak ShiftFeature CompressionRegroupingNoise IssuesFuture ApplicationsSummaryProblemsColor SensorsColor SensingHuman Color VisionColor SensorsColor Matching ExperimentsC...

  3. Elasto-viscoplastic self consistent modeling of the ambient temperature plastic behavior of periclase deformed up to 5.4 GPa

    Science.gov (United States)

    Lin, F.; Hilairet, N.; Raterron, P.; Addad, A.; Immoor, J.; Marquardt, H.; Tomé, C. N.; Miyagi, L.; Merkel, S.

    2017-11-01

    Anisotropy has a crucial effect on the mechanical response of polycrystalline materials. Polycrystal anisotropy is a consequence of single crystal anisotropy and texture (crystallographic preferred orientation) development, which can result from plastic deformation by dislocation glide. The plastic behavior of polycrystals is different under varying hydrostatic pressure conditions, and understanding the effect of hydrostatic pressure on plasticity is of general interest. Moreover, in the case of geological materials, it is useful for understanding material behavior in the deep earth and for the interpretation of seismic data. Periclase is a good material to test because of its simple and stable crystal structure (B1), and it is of interest to geosciences, as (Mg,Fe)O is the second most abundant phase in Earth's lower mantle. In this study, a polycrystalline sintered sample of periclase is deformed at ˜5.4 GPa and ambient temperature, to a total strain of 37% at average strain rates of 2.26 × 10-5/s and 4.30 × 10-5/s. Lattice strains and textures in the polycrystalline sample are recorded using in-situ synchrotron x-ray diffraction and are modeled with Elasto-Viscoplastic Self Consistent (EVPSC) methods. Parameters such as critical resolved shear stress (CRSS) for the various slip systems, strain hardening, initial grain shape, and the strength of the grain-neighborhood interaction are tested in order to optimize the simulation. At the beginning of deformation, a transient maximum occurs in lattice strains, then lattice strains relax to a "steady-state" value, which, we believe, corresponds to the true flow strength of periclase. The "steady state" CRSS of the {" separators="| 110 } ⟨" separators="| 1 1 ¯ 0 ⟩ slip system is 1.2 GPa, while modeling the transient maximum requires a CRSS of 2.2 GPa. Interpretation of the overall experimental data via modeling indicates dominant {" separators="| 110 } ⟨" separators="| 1 1 ¯ 0 ⟩ slip with initial strain

  4. Structural studies on volatile, air and moisture sensitive liquids at ambient and elevated temperatures using liquid X-ray scattering. The structure of liquid gallium (III) chloride systems

    Science.gov (United States)

    Ulvenlund, Stefan; Bengtsson, Lars A.

    1994-09-01

    An X-ray scattering method is presented which provides accurate structural information on air and moisture sensitive liquids at ambient and elevated temperatures using a standard θ-θ X-ray diffractometer. The method utilizes capillary glass tubes as sample containers and requires no corrections for sample container absorption or scattering, as shown by structural studies of well-known systems such as benzene, carbon tetrachloride and antimony trichloride. Artefacts produced by the sample holder are insignificant and very easy to correct for. The major drawback of the method is the long time of experiment, due to the small (compared with the standard set-up) area/volume ratio of the liquid which contributes to the intensity of the scattered radiation. However, the time required is not unduly long except for liquids containing light elements only (very low scattering power) or very heavy ones (high liner absorptivity). Liquid GaCl 3 is shown to have a dimeric structure consisting of edge-sharing GaCl 4 tetrahedra. This structure is analogous to that previously found for GaCl 3 in the gaseous and solid state and for AlCl 3 in the gaseous and liquid state. Concentrated solutions of GaCl 3 in benzene have been shown to comprise monomeric GaCl 3 units with C3v symmetry. However, it is suggested that such units form as a result of a radiolytically induced cleavage of the Ga 2Cl 6 moieties. No GaC correlation is resolved, which is explained by assuming a σ-type complex GaCl 3 and benzene and/or an ill-defined interaction between the GaCl 3 unit and benzene. The former sitution would most probably produce too few GaC correlation to be observable by the present method, whereas the latter situation would produce a very broad GaC correlation difficult to separate from the background. However, the deviation from the D3h symmetry adopted by GaCl 3 in the gas phase indicates a specific interation between GaCl 3 and benzene.

  5. Ambient Light Intensity, Actigraphy, Sleep and Respiration, Circadian Temperature and Melatonin Rhythms and Daytime Performance of Crew Members During Space Flight on STS-90 and STS-95 Missions

    Science.gov (United States)

    Czeisler, Charles A.; Dijk, D.-J.; Neri, D. F.; Hughes, R. J.; Ronda, J. M.; Wyatt, J. K.; West, J. B.; Prisk, G. K.; Elliott, A. R.; Young, L. R.

    1999-01-01

    Sleep disruption and associated waking sleepiness and fatigue are common during space flight. A survey of 58 crew members from nine space shuttle missions revealed that most suffered from sleep disruption, and reportedly slept an average of only 6.1 hours per day of flight as compared to an average of 7.9 hours per day on the ground. Nineteen percent of crewmembers on single shift missions and 50 percent of the crewmembers in dual shift operations reported sleeping pill usage (benzodiazepines) during their missions. Benzodiazepines are effective as hypnotics, however, not without adverse side effects including carryover sedation and performance impairment, anterograde amnesia, and alterations in sleep EEG. Our preliminary ground-based data suggest that pre-sleep administration of 0.3 mg of the pineal hormone melatonin may have the acute hypnotic properties needed for treating the sleep disruption of space flight without producing the adverse side effects associated with benzodiazepines. We hypothesize that pre-sleep administration of melatonin will result in decreased sleep latency, reduced nocturnal sleep disruption, improved sleep efficiency, and enhanced next-day alertness and cognitive performance both in ground-based simulations and during the space shuttle missions. Specifically, we have carried out experiments in which: (1) ambient light intensity aboard the space shuttle is assessed during flight; (2) the impact of space flight on sleep (assessed polysomnographically and actigraphically), respiration during sleep, circadian temperature and melatonin rhythms, waking neurobehavioral alertness and performance is assessed in crew members of the Neurolab and STS-95 missions; (3) the effectiveness of melatonin as a hypnotic is assessed independently of its effects on the phase of the endogenous circadian pacemaker in ground-based studies, using a powerful experimental model of the dyssomnia of space flight; (4) the effectiveness of melatonin as a hypnotic is

  6. Involvement of magnitude of ambient temperature change in nonspecific effect in perceived placebo effect on lower urinary tract symptoms: study on switching of naftopidil in patients with benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    Morita T

    2013-04-01

    Full Text Available Tatsuo Morita, Kenji Komatsu, Taro Kubo, Akira Fujisaki, Shinsuke Natsui, Akinori Nukui, Minoru Kobayashi, Shinsuke Kurokawa Department of Urology, Jichi Medical University, Tochigi, Japan Purpose: To determine if switching from one brand of the α1-adrenoceptor antagonist naftopidil (Avishot™ to another brand (Flivas™ under the same conditions causes the same changes in lower urinary tract symptoms (LUTS and quality of life (QOL as the perceived placebo effect, and if ambient temperature as a nonspecific factor is related to those changes in benign prostatic hyperplasia (BPH patients. Patients and methods: A retrospective study was carried out on 217 BPH patients who had received Avishot™ for more than 6 months and then were switched to Flivas™ at the same dose and timing. The two drugs contain the same principal ingredient and display the same pharmacokinetic properties. The International Prostate Symptom Score (IPSS, QOL score, and average monthly ambient temperature at the patients’ residence area from the Automated Meteorological Data Acquisition System in Japan were used for the evaluation. Results: A significant change in urinary storage symptoms (P = 0.006, and especially in nighttime frequency (P < 0.001, was observed by switching drugs, suggesting the perceived placebo effect. There was significant improvement of daytime frequency (P < 0.05, nighttime frequency (P < 0.001, storage symptoms (P < 0.001, and total IPSS (P < 0.05 when the magnitude of ambient temperature change from before and 3 months after switching drugs was higher than 10°C, while no significant improvement was noted in any